U.S. patent number 9,271,248 [Application Number 13/037,598] was granted by the patent office on 2016-02-23 for system and method for timing and frequency synchronization by a femto access point.
This patent grant is currently assigned to QUALCOMM Incorporated. The grantee listed for this patent is Olufunmilola O. Awoniyi, Kaushik Chakraborty, Samir Salib Soliman. Invention is credited to Olufunmilola O. Awoniyi, Kaushik Chakraborty, Samir Salib Soliman.
United States Patent |
9,271,248 |
Soliman , et al. |
February 23, 2016 |
System and method for timing and frequency synchronization by a
Femto access point
Abstract
Techniques are provided for frequency and timing synchronization
of a femto access point (FAP). In one example, the FAP may be
configured to establish an out-of-band (OOB) link with at least
user equipment (UE), and receive aiding parameters from the at
least one UE via the OOB link. The FAP may be configured to extract
frequency and timing information from at least one uplink packet of
the at least one UE based at least in part on the aiding
parameters. Extracting the frequency and timing information may
involve sniffing the at least one uplink packet to a macro base
station (e.g., eNB).
Inventors: |
Soliman; Samir Salib (San
Diego, CA), Awoniyi; Olufunmilola O. (San Diego, CA),
Chakraborty; Kaushik (San Diego, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
Soliman; Samir Salib
Awoniyi; Olufunmilola O.
Chakraborty; Kaushik |
San Diego
San Diego
San Diego |
CA
CA
CA |
US
US
US |
|
|
Assignee: |
QUALCOMM Incorporated (San
Diego, CA)
|
Family
ID: |
44065443 |
Appl.
No.: |
13/037,598 |
Filed: |
March 1, 2011 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20120052855 A1 |
Mar 1, 2012 |
|
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
61309730 |
Mar 2, 2010 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W
56/0025 (20130101); H04W 92/10 (20130101); H04W
84/045 (20130101) |
Current International
Class: |
H04W
36/00 (20090101); H04W 56/00 (20090101); H04W
92/10 (20090101); H04W 84/04 (20090101) |
Field of
Search: |
;455/456.1,422.1,436,411,41.2,67.13,1,432.1,437,458,522,63.1,67.11,103,404.2,408,444,450,456.6
;370/328,252,329,331,254,310,338,401 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
1398079 |
|
Feb 2003 |
|
CN |
|
1875648 |
|
Dec 2006 |
|
CN |
|
101155167 |
|
Apr 2008 |
|
CN |
|
101330322 |
|
Dec 2008 |
|
CN |
|
1089499 |
|
Apr 2001 |
|
EP |
|
1809056 |
|
Jul 2007 |
|
EP |
|
1871035 |
|
Dec 2007 |
|
EP |
|
2446192 |
|
Aug 2008 |
|
GB |
|
6334593 |
|
Dec 1994 |
|
JP |
|
2002505542 |
|
Feb 2002 |
|
JP |
|
2004112225 |
|
Apr 2004 |
|
JP |
|
2005184824 |
|
Jul 2005 |
|
JP |
|
2007534221 |
|
Nov 2007 |
|
JP |
|
2007536788 |
|
Dec 2007 |
|
JP |
|
2008172380 |
|
Jul 2008 |
|
JP |
|
4352281 |
|
Oct 2009 |
|
JP |
|
2009232434 |
|
Oct 2009 |
|
JP |
|
2009239568 |
|
Oct 2009 |
|
JP |
|
2010041537 |
|
Feb 2010 |
|
JP |
|
2010512054 |
|
Apr 2010 |
|
JP |
|
2010166163 |
|
Jul 2010 |
|
JP |
|
20100034579 |
|
Apr 2010 |
|
KR |
|
200926649 |
|
Jun 2009 |
|
TW |
|
9809390 |
|
Mar 1998 |
|
WO |
|
WO-9937037 |
|
Jul 1999 |
|
WO |
|
WO-9944306 |
|
Sep 1999 |
|
WO |
|
WO-2005048628 |
|
May 2005 |
|
WO |
|
WO-2005109767 |
|
Nov 2005 |
|
WO |
|
WO-2008066957 |
|
Jun 2008 |
|
WO |
|
2008094334 |
|
Aug 2008 |
|
WO |
|
2008139707 |
|
Nov 2008 |
|
WO |
|
WO-2008140225 |
|
Nov 2008 |
|
WO |
|
WO2009006041 |
|
Jan 2009 |
|
WO |
|
2009049207 |
|
Apr 2009 |
|
WO |
|
2010017226 |
|
Feb 2010 |
|
WO |
|
WO-2010022371 |
|
Feb 2010 |
|
WO |
|
2010033438 |
|
Mar 2010 |
|
WO |
|
WO-2010033413 |
|
Mar 2010 |
|
WO |
|
WO2010059750 |
|
May 2010 |
|
WO |
|
WO2011011760 |
|
Jan 2011 |
|
WO |
|
WO2011063044 |
|
May 2011 |
|
WO |
|
Other References
Yavuz M., et al.,"Interference management and performance analysis
of UMTS/HSPA+ femtocells", IEEE Communications Magazine, IEEE
Service Center, Piscataway, US, vol. 47, No. 9, Sep. 1, 2009, pp.
102-109, XP011283371, ISSN: 0163-6804, DOI:
10.1109/MCOM.2009.5277462. cited by applicant .
Co-pending U.S. Appl. No. 61/094,100, filed Sep. 4, 2008. cited by
applicant .
3GPP TR 36.922 version 9.0.0 Release 9; LTE; Evolved Universal
Terrestrial Radio Access (E-UTRA);TDD Home eNode B (HeNB) Radio
Frequency (RF) requirements analysis, ETSI TR 136 922 V9.0.0, pp.
1-77, Apr. 2010. cited by applicant .
"3rd Generation Partnership Project; Technical Specification Group
Radio Access Network; Evolved Universal Terrestrial Radio Access
(E-UTRA); TDD Home eNode B (HeNB) Radio Frequency (RF) requirements
analysis (Release 9)", 3GPP Standard; 3GPP TR 36.922, 3rd
Generation Partnership Project (3GPP), Mobile Competence Centre ;
650, Route Des Lucioles ; F-06921 Sophia-Antipolis Cedex ; France,
No. V9.1.0, Jun. 21, 2010, pp. 1-74, XP050441979, [retrieved on
Jun. 21, 2010]. cited by applicant .
3rd Generation Partnership Project, Technical Specification Group
Radio Access Networks, Home Node B Radio Frequency (RF)
Requirements (FDD) (Release 9), 3GPP Standard, 3GPP TR 25.967, 3rd
Generation Partnership Project (3GPP), Mobile Competence Centre,
650, Route Des Lucioles, F-06921 Sophia-Antipolis Cedex, France,
No. 9.0.0, May 1, 2009, pp. 1-55, XP050369580, paragraph [0007].
cited by applicant .
International Search Report and Written
Opinion--PCT/US2011/026800--ISA/EPO--Jun. 16, 2011. cited by
applicant .
LG Electronics: "Methods to facilitate the inter-cell coordination
in heterogeneous networks", 3GPP Draft; R1-105358
Coordinati0n.sub.--Method, 3rd Generation Partnership Project
(3GPP), Mobile Competence Centre ; 650, Route Des Lucioles ;
F-06921 Sophia-Antipolis Cedex ; France, vol. RAN WG1, No. Xi'an;
20101011, Oct. 5, 2010, XP050450509, [retrieved on Oct. 5, 2010].
cited by applicant .
Mediatek Inc: "Further Discussion on HeNB Downlink Power Setting in
HetNet", 3GPP Draft; R1-105238 Power Setting in HETNET, 3rd
Generation Partnership Project (3GPP), Mobile Competence Centre ;
650, Route Des Lucioles ; F-06921 Sophia-Antipolis Cedex; France,
vol. RAN WG1, No. Xi 'an; 20101011, Oct. 5, 2010, XP050450424,
[retrieved on Oct. 5, 2010]. cited by applicant .
Mitsubishi Electric: "Dynamic Setup of HNBs for Energy Savings and
Interference Reduction", 3GPP Draft; R3-081949 (Dynamic Setup
HNBS), 3rd Generation Partnership Project (3GPP), Mobile Competence
Centre ; 650, Route Des Lucioles ; F-06921 Sophia-Antipolis Cedex ;
France, vol . RAN WG3, no. Jeju Island; 20080813, Aug. 13, 2008,
XP050165010, [retrieved on Aug. 13, 2008]. cited by applicant .
Qualcomm Europe et al., "TDD HeNB Synchronization Requirement for
Large Propagation Distance Case", 3GPP Draft, R4-094985, 3rd
Generation Partnership Project (3GPP), Mobile Competence Centre,
650, Route Des Lucioles, F-06921 Sophia-Antipolis Cedex, France,
no. Jeju, 20091109, Nov. 9, 2009, XP050394434, [retrieved on Nov.
17, 2009]. cited by applicant .
Qualcomm Europe: "HeNB Timing Requirements", 3GPP Draft, R4-091902
Timing Requirements, 3rd Generation Partnership Project (3GPP),
Mobile Competence Centre, 650, Route Des Lucioles, F-06921
Sophia-Antipolis Cedex, France, no. San Francisco, 20090427, Apr.
27, 2009, XP050342629, [retrieved on Apr. 27, 2009] paragraph
[0002]. cited by applicant .
Qualcomm Europe: "Text Proposal on TDD HeNB Synchronization
Requirement", 3GPP Draft, R4-093725 Text Proposal for HeNB Sync
Requirements, 3rd Generation Partnership Project (3GPP), Mobile
Competence Centre, 650, Route Des Lucioles, F-06921
Sophia-Antipolis Cedex, France, no. Miyazaki, 20091012, Oct. 12,
2009, XP050393326, [retrieved on Oct. 6, 2009]. cited by applicant
.
Qualcomm Europe: "Synchronization Requirements and Techniques",
3GPP Draft, R4-091336, 3rd Generation Partnership Project (3GPP),
Mobile Competence Centre, 650, Route Des Lucioles, F-06921
Sophia-Antipolis Cedex, France, no. Seoul, Korea, 20090319, Mar.
19, 2009, XP050342103, [retrieved on Mar. 19, 2009]. cited by
applicant .
Universal Mobile Telecommunications System (UMTS), Physical layer,
Measurements (TDD) (3GPP TS 25.225 version 8.2.0 Release 8), ETSI
TS 125 225, ETSI Standard, European Telecommunications Standards
Institute (ETSI), Sophia Antipolis Cedex, France, vol. 3-R1, No.
V8.2.0, Mar. 1, 2009, XP014043978, paragraph [0007]. cited by
applicant .
Motorola: "PCID confusion", R2-092307, 3GPP TSG RAN WG2 #65bis Mar.
23-27, 2009, Seoul, Korea, pp. 1-3. cited by applicant .
Qualcomm Europe: "Network support for inbound handover of pre-Rel-9
UMTS UEs", R3-091213, 3GPP TSG RAN WG 3 #64, May 4-8, 2009 San
Francisco, USA, pp. 1-3. cited by applicant .
Damnjanovic et al., "A Survey on 3GPP Heterogeneous Networks", IEEE
Wireless Communications, pp. 10-21 (Jun. 2011). cited by applicant
.
Domenico A.D., et al., "A Survey on MAC Strategies for Cognitive
Radio Networks", IEEE Communications Surveys, IEEE, New York, NY,
US, vol. 14, No. 1, Jan. 1, 2012, pp. 21-44, XP011420410, ISSN:
1553-877X, DOI: 10.1109/SURV.2011.111510.00108. cited by
applicant.
|
Primary Examiner: Casca; Fred
Parent Case Text
CLAIM OF PRIORITY UNDER 35 U.S.C. .sctn.119
The present Application for patent claims priority to Provisional
Application No. 61/309,730, entitled "METHOD AND APPARATUS TO
ENABLE TIMING AND FREQUENCY SYNCHRONIZATION BASED ON INTERFERENCE
FROM WIRELESS DEVICES," filed Mar. 2, 2010, and is assigned to the
assignee hereof, and is hereby expressly incorporated in its
entirety by reference herein.
Claims
What is claimed is:
1. A method for frequency and timing synchronization by a femto
access point (FAP), comprising: establishing, by a processor of the
FAP, an out-of-band (OOB) link between the FAP and at least one
user equipment (UE), wherein the at least one UE is being serviced
by a network entity macro base station other than the FAP;
receiving aiding parameters from the at least one UE via the OOB
link; and in response to the at least one UE being in a CELL_DCH
state or a CELL_FACH state, sniffing, by the FAP, at least one
uplink packet directed from the at least one UE to the network
entity macro base station at least by extracting frequency and
timing information from the at least one uplink packet of the at
least one UE based at least in part on the aiding parameters.
2. The method of claim 1, wherein receiving the aiding parameters
comprises receiving information regarding at least one of UE
state(s), UE technology type(s), and channel detection parameter(s)
from the at least one UE.
3. The method of claim 2, wherein the channel detection
parameter(s) comprise scrambling code(s).
4. The method of claim 1, wherein receiving the aiding parameters
comprises requesting the aiding parameters from the at least one UE
via the OOB link.
5. The method of claim 1, wherein the macro base station comprises
one of a Node B and an evolved Node B (eNB).
6. The method of claim 5, wherein sniffing further comprises: in
response to the network entity macro base station comprising an
eNB, monitoring information in at least one of a physical random
access channel (PRACH), a demodulation reference signal (DMRS), and
a sounding reference signal (SRS) between the at least one UE and
the eNB.
7. The method of claim 1, wherein the aiding parameters comprise
information regarding: signatures, spreading codes and scrambling
codes for the at least one UE which the at least one UE received as
broadcasted system information from the network entity macro base
station determining the timing and frequency information based at
least in part on the obtained information.
8. The method of claim 1, wherein, the extracting is in response to
the FAP being in an active set of the at least one UE.
9. The method of claim 1, wherein, the extracting is in response to
the FAP not being in an active set of the at least one UE.
10. The method of claim 1, wherein the OOB link comprises a
Bluetooth link.
11. An apparatus for frequency and timing synchronization of a
femto access point (FAP), comprising: at least one processor
configured to: establish, by the FAP, an out-of-band (OOB) link
between the FAP and at least one user equipment (UE), wherein the
at least one UE is being serviced by a network entity macro base
station other than the FAP; receive aiding parameters from the at
least one UE via the OOB link; and in response to the at least one
UE being in a CELL_DCH state or a CELL_FACH state, sniff, by the
FAP, at least one uplink packet directed from the at least one UE
to the network entity macro base station at least by extracting
frequency and timing information from the at least one uplink
packet of the at least one UE based at least in part on the aiding
parameters; and a memory coupled to the at least one processor for
storing data.
12. The apparatus of claim 11, wherein the at least one processor
receives the aiding parameters by receiving information regarding
at least one of UE state(s), UE technology type(s), and channel
detection parameter(s) from the at least one UE.
13. The apparatus of claim 11, wherein the at least one processor
requests the aiding parameters from the at least one UE via the OOB
link.
14. The apparatus of claim 11, wherein the aiding parameters
comprise information regarding: signatures, spreading codes and
scrambling codes for the at least one UE which the at least one UE
received as broadcasted system information from the network entity
macro base station.
15. The apparatus of claim 11, wherein the at least one processor
sniffs by: in response to the network entity macro base station
comprising an evolved Node B (eNB), monitoring information in at
least one of a physical random access channel (PRACH), a
demodulation reference signal (DMRS), and a sounding reference
signal (SRS) between the at least one UE and the eNB.
16. An apparatus, comprising: means for establishing an out-of-band
(OOB) link between the apparatus and at least one user equipment
(UE), wherein the at least one UE is being serviced by a network
entity serving macro base station other than the apparatus; means
for receiving aiding parameters from the at least one UE via the
OOB link; and means for, in response to the at least one UE being
in a CELL_DCH state or a CELL_FACH state, sniffing, by the FAP, at
least one uplink packet directed from the at least one UE to the
network entity macro base station at least by extracting frequency
and timing information from the at least one uplink packet of the
at least one UE based at least in part on the aiding
parameters.
17. The apparatus of claim 16, further comprising means for
receiving information regarding at least one of UE state(s), UE
technology type(s), and channel detection parameter(s) from the at
least one UE.
18. The apparatus of claim 16, further comprising means for
requesting the aiding parameters from the at least one UE via the
OOB link.
19. The apparatus of claim 16, wherein the aiding parameters
comprise information regarding: signatures, spreading codes and
scrambling codes for the at least one UE which the at least one UE
received as broadcasted system information from the network entity
macro base station, in response to the at least one UE being in a
CELL_FACH state; and means for determining the timing and frequency
information based at least in part on the obtained information.
20. The apparatus of claim 16, wherein the at least one processor
further sniffs by: means for monitoring information in at least one
of a physical random access channel (PRACH), a demodulation
reference signal (DMRS), and a sounding reference signal (SRS)
between the at least one UE and the network entity macro base
station, in response to the network entity macro base station
comprising an eNB.
21. A non-transitory computer-readable medium having
computer-readable instructions stored therein that when executed
cause a computing device to: establish, by a processor of a femto
access point (FAP), an out-of-band (OOB) link between the computing
device and at least one user equipment (UE), wherein the at least
one UE is being serviced by a network entity macro base station
other than the computing device; receive aiding parameters from the
at least one UE via the OOB link; and in response to the at least
one UE being in a CELL_DCH state or a CELL_FACH state, sniff, by
the FAP, at least one uplink packet directed from the at least one
UE to the network entity macro base station at least by extracting
frequency and timing information from the at least one uplink
packet of the at least one UE based at least in part on the aiding
parameters.
22. The computer readable medium of claim 21, wherein the
computer-readable instructions, when executed, further cause the
computing device to receive information regarding at least one of
UE state(s), UE technology type(s), and channel detection
parameter(s) from the at least one UE.
23. The computer readable medium of claim 21, wherein the
computer-readable instructions, when executed, further cause the
computing device to request the aiding parameters from the at least
one UE via the OOB link.
24. The computer readable medium of claim 21, wherein the aiding
parameters comprise information regarding: signatures, spreading
codes and scrambling codes for the at least one UE which the at
least one UE received as broadcasted system information from the
network entity macro base station.
25. The computer readable medium of claim 21, wherein the
computer-readable instructions, when executed, further cause the
computing device to: monitor information in at least one of a
physical random access channel (PRACH), a demodulation reference
signal (DMRS), and a sounding reference signal (SRS) between the at
least one UE and the network entity macro base station, in response
to the network entity macro base station comprising an eNB.
26. A method for femto access point (FAP) synchronization by a user
equipment (UE), comprising: determining whether an out-of-band
(OOB) link is established, by a processor of a FAP, between the UE
and the FAP, wherein the UE is being serviced by a network entity
macro base station other than the FAP; and in response to
determining that the OOB link is established, providing aiding
parameters to the FAP via the OOB link, wherein, in response to the
UE being in a CELL_DCH state or a CELL_FACH state, frequency and
timing information from at least one uplink packet directed from
the UE to the network entity macro base station is extracted, by
sniffing of the at least one uplink packet by the FAP, based at
least in part on the aiding parameters.
27. The method of claim 26, wherein providing the aiding parameters
comprises sending information regarding at least one of UE
state(s), UE technology type(s), and channel detection parameter(s)
to the FAP.
28. The method of claim 27, wherein the channel detection
parameter(s) comprise scrambling codes.
29. The method of claim 26, wherein the network entity macro base
station comprises one of a Node B and an evolved Node B (eNB).
30. The method of claim 26, further comprising: receiving
broadcasted system information from the network entity macro base
station, in response to the UE being in a CELL_FACH state; and
sending the broadcasted system information to the FAP.
31. The method of claim 30, wherein sending comprises sending the
broadcasted system to the FAP via the OOB link.
32. The method of claim 26, wherein the aiding parameters comprise
information regarding: spreading codes, scrambling codes, and
timing offsets to the FAP over an OOB link.
33. The method of claim 26, further comprising initiating
establishment of the OOB link, in response to determining that the
OOB link is not already established.
34. The method of claim 26, wherein providing comprises initiating
the transfer of the aiding parameters to the FAP via the OOB
link.
35. The method of claim 26, further comprising, in response to
determining that the OOB link is not established, paging the FAP to
establish the OOB link.
36. The method of claim 26, further comprising: receiving at least
one of broadcasted system information and dedicated system
information from the network entity macro base station, in response
to the UE being in a LTE connected state; and sending the at least
one the broadcasted system information and the dedicated signaling
information to the FAP over an OOB link.
37. An apparatus for femto access point (FAP) synchronization by a
user equipment (UE), comprising: at least one processor configured
to: determine whether an out-of-band (OOB) link is established
between the UE and a FAP, wherein the UE is being serviced by a
network entity macro base station other than the FAP; and provide
aiding parameters to the FAP via the OOB link, in response to
determining that the OOB link is established, wherein, in response
to the UE being in a CELL_DCH state or a CELL_FACH state, frequency
and timing information from at least one uplink packet directed
from the UE to the network entity macro base station is extracted,
by sniffing of the at least one uplink packet by the FAP, based at
least in part on the aiding parameters; and a memory coupled to the
at least one processor for storing data.
38. The apparatus of claim 37, wherein the at least one processor
provides the aiding parameters by sending information regarding at
least one of UE state(s), UE technology type(s), and channel
detection parameter(s) to the FAP.
39. The apparatus of claim 37, wherein the at least one processor:
receives broadcasted system information from the network entity
macro base station, in response to the UE being in a CELL_FACH
state; and sends the broadcasted system information to the FAP.
40. The apparatus of claim 39, wherein the at least one processor
sends the broadcasted system to the FAP via the OOB link.
41. The apparatus of claim 37, wherein the aiding parameters
comprise information regarding: spreading codes, scrambling codes,
and timing offsets to the FAP over an OOB link.
42. The apparatus of claim 37, wherein the at least one processor
initiates establishment of the OOB link, in response to determining
that the OOB link is not already established.
43. The apparatus of claim 37, wherein the at least one processor
initiates the transfer of the aiding parameters to the FAP via the
OOB link.
44. The apparatus of claim 37, wherein the at least one processor
pages the FAP to establish the OOB link, in response to determining
that the OOB link is not established.
45. The apparatus of claim 37, wherein the at least one processor:
receives at least one of broadcasted system information and
dedicated system information from the network entity macro base
station, in response to the UE being in a LTE connected state; and
sends the at least one the broadcasted system information and the
dedicated signaling information to the FAP over an OOB link.
46. User equipment (UE), comprising: means for determining whether
an out-of-band (OOB) link is established between the UE and a FAP,
wherein the UE is being serviced by a network entity macro base
station other than the FAP; and means for providing aiding
parameters to the FAP via the OOB link, in response to determining
that the OOB link is established, wherein, in response to the UE
being in a CELL_DCH state or a CELL_FACH state, frequency and
timing information from at least one uplink packet directed from
the UE to the network entity macro base station is extracted, by
sniffing of the at least one uplink packet by the FAP, based at
least in part on the aiding parameters.
47. The UE of claim 46, further comprising means for sending
information regarding at least one of UE state(s), UE technology
type(s), and channel detection parameter(s) to the FAP.
48. The UE of claim 46, further comprising: means for receiving
broadcasted system information from the network entity macro base
station, in response to the UE being in a CELL_FACH state; and
means for sending the broadcasted system information to the
FAP.
49. The UE of claim 48, further comprising means for sending the
broadcasted system to the FAP via the OOB link.
50. The UE of claim 46, wherein the aiding parameters comprise
information regarding: spreading codes, scrambling codes, and
timing offsets to the FAP over an OOB link.
51. The UE of claim 46, further comprising means for initiating
establishment of the OOB link, in response to determining that the
OOB link is not already established.
52. The UE of claim 46, further comprising means for initiating the
transfer of the aiding parameters to the FAP via the OOB link.
53. The UE of claim 46, further comprising means for paging the FAP
to establish the OOB link, in response to determining that the OOB
link is not established.
54. The UE of claim 46, further comprising: means for receiving at
least one of broadcasted system information and dedicated system
information from the network entity macro base station, in response
to the UE being in a LTE connected state; and means for sending the
at least one the broadcasted system information and the dedicated
signaling information to the FAP over an OOB link.
55. A non-transitory computer-readable medium having
computer-readable instructions stored therein that when executed
cause user equipment (UE) to: determine whether an out-of-band
(OOB) link is established between the UE and a FAP, wherein the UE
is being serviced by a network entity macro base station other than
the FAP; and in response to determining that the OOB link is
established, provide aiding parameters to the FAP via the OOB link,
wherein, in response to the UE being in a CELL_DCH state or a
CELL_FACH state, frequency and timing information from at least one
uplink packet directed from the UE to the network entity macro base
station is extracted, by sniffing of the at least one uplink packet
by the FAP, based at least in part on the aiding parameters.
56. The computer readable medium of claim 55, wherein the
computer-readable instructions, when executed, further cause the
computing device to send information regarding at least one of UE
state(s), UE technology type(s), and channel detection parameter(s)
to the FAP.
57. The computer readable medium of claim 55, wherein the
computer-readable instructions, when executed, further cause the
computing device to: receive broadcasted system information from
the network entity macro base station, in response to the UE being
in a CELL_FACH state; and send the broadcasted system information
to the FAP.
58. The computer readable medium of claim 57, further comprising
means for sending the broadcasted system to the FAP via the OOB
link.
59. The computer readable medium of claim 55, wherein the aiding
parameters comprise information regarding: spreading codes,
scrambling codes, and timing offsets to the FAP over an OOB
link.
60. The computer readable medium of claim 55, wherein the
computer-readable instructions, when executed, further cause the
computing device to initiate establishment of the OOB link, in
response to determining that the OOB link is not already
established.
61. The computer readable medium of claim 55, wherein the
computer-readable instructions, when executed, further cause the
computing device to initiate the transfer of the aiding parameters
to the FAP via the OOB link.
62. The computer readable medium of claim 55, wherein the
computer-readable instructions, when executed, further cause the
computing device to page the FAP to establish the OOB link, in
response to determining that the OOB link is not established.
63. The computer readable medium of claim 55, wherein the
computer-readable instructions, when executed, further cause the
computing device to: receive at least one of broadcasted system
information and dedicated system information from the network
entity macro base station, in response to the UE being in a LTE
connected state; and send the at least one the broadcasted system
information and the dedicated signaling information to the FAP over
an OOB link.
64. A method for frequency and timing synchronization by a femto
access point (FAP) and a user equipment (UE), comprising:
establishing, by a processor of the FAP, an out-of-band (OOB) link
with the UE, wherein the UE is being serviced by a network entity
macro base station other than the FAP; determining, by the UE,
whether the out-of-band (OOB) link is established with the FAP; in
response to determining that the OOB link is established, providing
aiding parameters to the FAP via the OOB link; receiving the aiding
parameters from the UE via the OOB link; and in response to the at
least one UE being in a CELL_DCH state or a CELL_FACH state,
sniffing, by the FAP, at least one uplink packet directed from the
at least one UE to the network entity macro base station at least
by extracting frequency and timing information from at least one
uplink packet of the UE based at least in part on the aiding
parameters.
Description
BACKGROUND
1. Field
The present application relates generally to wireless
communications, and more specifically to techniques for
synchronizing a femto cell to a macro cell in a wireless
communication network.
2. Background
Wireless communication networks are widely deployed to provide
various communication content such as voice, video, packet data,
messaging, broadcast, etc. These wireless networks may be
multiple-access networks capable of supporting multiple users by
sharing the available network resources. Examples of such
multiple-access networks include Code Division Multiple Access
(CDMA) networks, Time Division Multiple Access (TDMA) networks,
Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA
(OFDMA) networks, and Single-Carrier FDMA (SC-FDMA) networks.
In recent years, users have started to replace fixed line broadband
communications with mobile broadband communications and have
increasingly demanded great voice quality, reliable service, and
low prices, especially at their home or office locations. In order
to provide indoor services, network operators may deploy different
solutions. For networks with moderate traffic, operators may rely
on macro cellular base stations to transmit the signal into
buildings. However, in areas where building penetration loss is
high, it may be difficult to maintain acceptable signal quality,
and thus other solutions are desired. New solutions are frequently
desired to make the best of the limited radio resources such as
space and spectrum. Some of these solutions include intelligent
repeaters, remote radio heads, pico cells, and femto cells.
The Femto Forum, a non-profit membership organization focused on
standardization and promotion of femto cell solutions, defines
femto access points (FAPs), also referred to as femto cell units,
to be low-powered wireless access points that operate in licensed
spectrum and are controlled by the network operator, can be
connected with existing handsets, and use a residential digital
subscriber line (DSL) or cable connection for backhaul. In various
standards or contexts, a FAP may be referred to as a home node B
(HNB), home e-node B (HeNB), access point base station, etc.
In order to keep the expenses low, it is desired for FAPs to
require very little for installation and setup. This means that a
FAP may be designed to auto-configure itself such that the user
only needs to plug in the cables for the internet connection and
electricity, and the timing and frequency synchronization of the
FAP with the macro cell is taken care of automatically.
SUMMARY
The following presents a simplified summary of one or more
embodiments in order to provide a basic understanding of such
embodiments. This summary is not an extensive overview of all
contemplated embodiments, and is intended to neither identify key
or critical elements of all embodiments nor delineate the scope of
any or all embodiments. Its sole purpose is to present some
concepts of one or more embodiments in a simplified form as a
prelude to the more detailed description that is presented
later.
In accordance with one or more embodiments and corresponding
disclosure thereof, various aspects are described in connection
with methods for frequency and timing synchronization by a femto
access point (FAP). The method may involve establishing an
out-of-band (OOB) link with at least one user equipment (UE). The
method may involve receiving aiding parameters from the at least
one UE via the OOB link. The method may involve extracting
frequency and timing information from at least one uplink packet of
the at least one UE based at least in part on the aiding
parameters. In further related aspects, an electronic device may be
configured to execute the above described methodology.
In accordance with one or more embodiments and corresponding
disclosure thereof, various aspects are described in connection
with a FAP synchronization method that may be performed by a mobile
entity, such as a UE. In one embodiment, the method may involve
determining whether an OOB link is established with a FAP. The
method may involve, in response to determining that the OOB link is
established, providing aiding parameters to the FAP via the OOB
link. In further related aspects, an electronic device may be
configured to execute the above described methodology.
To the accomplishment of the foregoing and related ends, the one or
more embodiments comprise the features hereinafter fully described
and particularly pointed out in the claims. The following
description and the annexed drawings set forth in detail certain
illustrative aspects of the one or more embodiments. These aspects
are indicative, however, of but a few of the various ways in which
the principles of various embodiments may be employed and the
described embodiments are intended to include all such aspects and
their equivalents.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a wireless communication network.
FIG. 2 is a conceptual diagram illustrating an example of a
hardware implementation for an apparatus employing a processing
system.
FIG. 3 illustrates an exemplary communication system to enable
deployment of FAPs within a network environment.
FIGS. 4A-B are a block diagrams illustrating a FAP and a UE
according to an aspect of the disclosure.
FIG. 5A is a conceptual diagram illustrating the utilization of
interference from UEs by a neighboring FAP according to an aspect
of the disclosure.
FIG. 5B shows an embodiment of a system for communicating aiding
parameters over an OOB link.
FIG. 6 is a timing diagram illustrating timing relationships
between transmissions on the P-CCPCH and AICH channels.
FIG. 7 is a timing diagram illustrating timing relationships
between transmissions on the PRACH and AICH channels.
FIG. 8 is a timing diagram illustrating timing relationships
between the PRACH, AICH, F-DPCH, and DPCCH transmissions.
FIG. 9 is a timing diagram illustrating a timing relationship at
the UE between the F-DPCH and the UL DPCCH transmissions.
FIG. 10 is a conceptual diagram illustrating the generation of a
preamble signal.
FIG. 11 is a conceptual diagram illustrating PRACH physical layer
processing.
FIG. 12 is a conceptual diagram illustrating UL DPCCH and UL DPDCH
physical layer processing.
FIGS. 13A-B are timing diagrams illustrating timing relationships
between UL DPCCH, P-CCPCH and DPCH or F-DPCH transmissions.
FIG. 14 is a timing diagram illustrating the determination of the
slot timing of the P-CCPCH using the PRACH preamble and PRACH
message part in the CELL_FACH state in accordance with an aspect of
the disclosure.
FIG. 15 is a timing diagram illustrating the determination of the
slot timing of the P-CCPCH using the PRACH message part in the
CELL_FACH state in accordance with an aspect of the disclosure.
FIG. 16 is a timing diagram illustrating the determination of the
slot timing of the P-CCPCH using the UL DPCCH in the CELL_FACH
state in accordance with an aspect of the disclosure.
FIG. 17 is a timing diagram illustrating the determination of the
slot and frame timing of the P-CCPCH using the UL DPCCH in the
CELL_DCH state in accordance with an aspect of the disclosure.
FIGS. 18A-B are flow charts illustrating a process for determining
the slot timing of the P-CCPCH as shown in the timing diagrams of
FIGS. 14-17 in accordance with an aspect of the disclosure.
FIG. 19 illustrates an example methodology for frequency and timing
synchronization by a FAP.
FIGS. 20A-B illustrate further aspects of the methodology of FIG.
19.
FIG. 21 illustrates an example methodology for FAP synchronization
by a mobile entity.
FIGS. 22A-B illustrate further aspects of the methodology of FIG.
21.
FIG. 23 shows an example apparatus for FAP synchronization, in
accordance with the methodology of FIGS. 19-20B.
FIG. 24 shows an example apparatus for FAP synchronization, in
accordance with the methodology of FIGS. 21-22B.
DETAILED DESCRIPTION
The word "exemplary" is used herein to mean "serving as an example,
instance, or illustration." Any embodiment described herein as
"exemplary" is not necessarily to be construed as preferred or
advantageous over other embodiments. The techniques described
herein may be used for various wireless communication networks such
as CDMA, TDMA, FDMA, OFDMA, SC-FDMA and other wireless networks.
The terms "network" and "system" are often used interchangeably. A
CDMA network may implement a radio technology such as Universal
Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes
Wideband CDMA (WCDMA), Time Division Synchronous CDMA (TD-SCDMA),
and other variants of CDMA. cdma2000 covers IS-2000, IS-95 and
IS-856 standards. A TDMA network may implement a radio technology
such as Global System for Mobile Communications (GSM). An OFDMA
network may implement a radio technology such as Evolved UTRA
(E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE
802.16 (WiMAX), IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are
part of Universal Mobile Telecommunication System (UMTS). 3GPP Long
Term Evolution (LTE) and LTE-Advanced (LTE-A), in both FDD and TDD,
are new releases of UMTS that use E-UTRA, which employs OFDMA on
the downlink and SC-FDMA on the uplink. UTRA, E-UTRA, UMTS, LTE,
LTE-A and GSM are described in documents from an organization named
"3rd Generation Partnership Project" (3GPP). cdma2000 and UMB are
described in documents from an organization named "3rd Generation
Partnership Project 2" (3GPP2). The techniques described herein may
be used for the wireless networks and radio technologies mentioned
above as well as other wireless networks and radio technologies.
For clarity, certain aspects of the techniques are described below
for LTE, and LTE terminology is used in much of the description
below.
FIG. 1 shows a wireless communication network 100, which may be an
LTE network or some other wireless network. Wireless network 100
may include a number of evolved Node Bs (eNBs) 110 and other
network entities. An eNB may be an entity that communicates with
the UEs and may also be referred to as a base station, a Node B, an
access point, etc. Although the eNB typically has more
functionalities than a base station, the terms "eNB" and "base
station" are used interchangeably herein. Each eNB 110 may provide
communication coverage for a particular geographic area and may
support communication for mobile entities (MEs), such as, for
example, user equipment (UEs) located within the coverage area. To
improve network capacity, the overall coverage area of an eNB may
be partitioned into multiple (e.g., three) smaller areas. Each
smaller area may be served by a respective eNB subsystem. In 3GPP,
the term "cell" can refer to the smallest coverage area of an eNB
and/or an eNB subsystem serving this coverage area, depending on
the context in which the term is used.
An eNB may provide communication coverage for a macro cell, a pico
cell, a femto cell, and/or other types of cell. A macro cell may
cover a relatively large geographic area (e.g., several kilometers
in radius) and may allow unrestricted access by UEs with service
subscription. A pico cell may cover a relatively small geographic
area and may allow unrestricted access by UEs with service
subscription. A femto cell may cover a relatively small geographic
area (e.g., a home) and may allow restricted access by UEs having
association with the femto cell (e.g., UEs in a Closed Subscriber
Group (CSG)). In the example shown in FIG. 1, eNBs 110a, 110b, and
110c may be macro eNBs for macro cell groups 102a, 102b, and 102c,
respectively. Each of the cell groups 102a, 102b, and 102c may
include a plurality (e.g., three) of cells or sectors. An eNB 110d
may be a pico eNB for a pico cell 102d. An eNB 110e may be a femto
eNB or femto access point (FAP) for a femto cell 102e.
Wireless network 100 may also include relays (not shown in FIG. 1).
A relay may be an entity that can receive a transmission of data
from an upstream station (e.g., an eNB or a UE) and send a
transmission of the data to a downstream station (e.g., a UE or an
eNB). A relay may also be a UE that can relay transmissions for
other UEs.
A network controller 130 may couple to a set of eNBs and may
provide coordination and control for these eNBs. Network controller
130 may comprise a single network entity or a collection of network
entities. Network controller 130 may communicate with the eNBs via
a backhaul. The eNBs may also communicate with one another, e.g.,
directly or indirectly via a wireless or wireline backhaul.
UEs 120 may be dispersed throughout wireless network 100, and each
UE may be stationary or mobile. A UE may also be referred to as a
mobile station, a terminal, an access terminal, a subscriber unit,
a station, etc. A UE may be a cellular phone, a personal digital
assistant (PDA), a wireless modem, a wireless communication device,
a handheld device, a laptop computer, a cordless phone, a wireless
local loop (WLL) station, a smart phone, a netbook, a smartbook,
etc. A UE may be able to communicate with eNBs, relays, etc. A UE
may also be able to communicate peer-to-peer (P2P) with other
UEs.
Wireless network 100 may support operation on a single carrier or
multiple carriers for each of the downlink and uplink. A carrier
may refer to a range of frequencies used for communication and may
be associated with certain characteristics. Operation on multiple
carriers may also be referred to as multi-carrier operation or
carrier aggregation. A UE may operate on one or more carriers for
the downlink (or downlink carriers) and one or more carriers for
the uplink (or uplink carriers) for communication with an eNB. The
eNB may send data and control information on one or more downlink
carriers to the UE. The UE may send data and control information on
one or more uplink carriers to the eNB. In one design, the downlink
carriers may be paired with the uplink carriers. In this design,
control information to support data transmission on a given
downlink carrier may be sent on that downlink carrier and an
associated uplink carrier. Similarly, control information to
support data transmission on a given uplink carrier may be sent on
that uplink carrier and an associated downlink carrier. In another
design, cross-carrier control may be supported. In this design,
control information to support data transmission on a given
downlink carrier may be sent on another downlink carrier (e.g., a
base carrier) instead of the downlink carrier.
Wireless network 100 may support carrier extension for a given
carrier. For carrier extension, different system bandwidths may be
supported for different UEs on a carrier. For example, the wireless
network may support (i) a first system bandwidth on a downlink
carrier for first UEs (e.g., UEs supporting LTE Release 8 or 9 or
some other release) and (ii) a second system bandwidth on the
downlink carrier for second UEs (e.g., UEs supporting a later LTE
release). The second system bandwidth may completely or partially
overlap the first system bandwidth. For example, the second system
bandwidth may include the first system bandwidth and additional
bandwidth at one or both ends of the first system bandwidth. The
additional system bandwidth may be used to send data and possibly
control information to the second UEs.
Wireless network 100 may support data transmission via single-input
single-output (SISO), single-input multiple-output (SIMO),
multiple-input single-output (MISO), and/or multiple-input
multiple-output (MIMO). For MIMO, a transmitter (e.g., an eNB) may
transmit data from multiple transmit antennas to multiple receive
antennas at a receiver (e.g., a UE). MIMO may be used to improve
reliability (e.g., by transmitting the same data from different
antennas) and/or to improve throughput (e.g., by transmitting
different data from different antennas).
Wireless network 100 may support single-user MIMO, multi-user MIMO,
Coordinated Multi-Point (CoMP), etc. For SU-MIMO, a cell may
transmit multiple data streams to a single UE on a given
time-frequency resource with or without precoding. For MU-MIMO, a
cell may transmit multiple data streams to multiple UEs (e.g., one
data stream to each UE) on the same time-frequency resource with or
without precoding. CoMP may include cooperative transmission and/or
joint processing. For cooperative transmission, multiple cells may
transmit one or more data streams to a single UE on a given
time-frequency resource such that the data transmission is steered
toward the intended UE and/or away from one or more interfered UEs.
For joint processing, multiple cells may transmit multiple data
streams to multiple UEs (e.g., one data stream to each UE) on the
same time-frequency resource with or without precoding.
Wireless network 100 may support hybrid automatic retransmission
(HARQ) in order to improve reliability of data transmission. For
HARQ, a transmitter (e.g., an eNB) may send a transmission of a
data packet (or transport block) and may send one or more
additional transmissions, if needed, until the packet is decoded
correctly by a receiver (e.g., a UE), or the maximum number of
transmissions has been sent, or some other termination condition is
encountered. The transmitter may thus send a variable number of
transmissions of the packet. For synchronous HARQ, all
transmissions of the packet may be sent in subframes of a single
HARQ interlace, which may include every Q-th subframes, where Q may
be equal to 4, 6, 8, 10, or some other value. For asynchronous
HARQ, each transmission of the packet may be sent in any
subframe.
Wireless network 100 may support synchronous or asynchronous
operation. For synchronous operation, the eNBs may have similar
frame timing, and transmissions from different eNBs may be
approximately aligned in time. For asynchronous operation, the eNBs
may have different frame timing, and transmissions from different
eNBs may not be aligned in time.
Wireless network 100 may utilize FDD or TDD. For FDD, the downlink
and uplink may be allocated separate frequency channels, and
downlink transmissions and uplink transmissions may be sent
concurrently on the two frequency channels. For TDD, the downlink
and uplink may share the same frequency channel, and downlink and
uplink transmissions may be sent on the same frequency channel in
different time periods. In related aspects, the FAP synchronization
algorithm described in further detail below may be applied to the
FAPs using FDD or TDD duplexing.
FIG. 2 is a conceptual diagram illustrating an example of a
hardware implementation for an apparatus 200 employing a processing
system 214. For example, the apparatus 200 may comprise a mobile
entity, such as a UE or the like, or a network entity, such as a
macro base station (e.g., an eNB), a FAP, or the like. In this
example, the processing system 214 may be implemented with a bus
architecture, represented generally by the bus 202. The bus 202 may
include any number of interconnecting buses and bridges depending
on the specific application of the processing system 214 and the
overall design constraints. The bus 202 links together various
circuits including one or more processors, represented generally by
the processor 204, and computer-readable media, represented
generally by the computer-readable medium 206. The bus 202 may also
link various other circuits such as timing sources, peripherals,
voltage regulators, and power management circuits, which are well
known in the art, and therefore, will not be described any further.
A bus interface 208 provides an interface between the bus 202 and a
transceiver 210. The transceiver 210 provides a means for
communicating with various other apparatus over a transmission
medium. Depending upon the nature of the apparatus, a user
interface 212 (e.g., keypad, display, speaker, microphone, and/or
joystick) may also be provided.
The processor 204 may be responsible for managing the bus 202 and
general processing, including the execution of software stored on
the computer-readable medium 206. The software, when executed by
the processor 204, causes the processing system 214 to perform the
various functions described infra for any particular apparatus. The
computer-readable medium 206 may also be used for storing data that
is manipulated by the processor 204 when executing software.
FIG. 3 illustrates an exemplary communication system to enable
deployment of femto cells within a network environment. As shown in
FIG. 3, the system 300 includes a FAP 310 installed in a
corresponding small scale network environment, such as, for
example, in one or more user residences 330, and being configured
to serve associated, as well as alien, mobile stations 320a and
320b. The FAP 310 may be coupled to the Internet 340 by way of a
backhaul connection 335, for example, a cable or digital subscriber
line (DSL) connection. The FAP 310 is further communicatively
coupled to a mobile operator core network 350 via the Internet 340
utilizing suitable communication hardware and software. Further,
the FAP 310 may be communicatively coupled to one or more macro
cell base stations 360 utilizing a network listen component 370 for
sniffing the air interface broadcasted by one or more of the macro
cell base stations 360 and/or for sniffing uplink packets from
mobile entities (e.g., UEs).
FIG. 4A is a conceptual block diagram that illustrates one example
of the FAP 310 shown in FIG. 3. In the figure, a number of blocks
are labeled as processors or controllers. Those skilled in the art
will comprehend that each of these processors may be implemented as
hardware processors such as the processor 204 or the processing
system 214 illustrated in FIG. 2, or alternatively, the functions
performed by any number of the illustrated processors may be
combined into and implemented by a single hardware processor.
Further, the illustrated processors in FIG. 4A may represent
functions to be implemented by processors, software, or the
like.
As noted above, the FAP 310 may include a network listen component
370. The network listen component 370 generally functions like the
eyes and ears of the FAP 310 to configure the FAP 310 and retrieve
timing and frequency information for synchronization. The network
listen component 370 may include a downlink receiver 371 and a
receive processor 372 for receiving and measuring signal and
interference levels on various available channels. The network
listen component 370 may further utilize the receiver 371 and
receive processor 372 to acquire timing and frequency information
from neighboring cells and decode broadcast messages from those
cells for mobility and interference management purposes. For
example, the network listen component 370 may achieve this by
periodically scanning the surrounding cells. The FAP 310 may
further include wireless wide area network (WWAN) components
including a WWAN transceiver 311 and WWAN processor 312, and
wireless personal area network (WPAN) components including a WPAN
transceiver 313 and WPAN processor 314. Here, the WPAN components
are optional, and may be utilized for out-of-band (OOB)
communication with UEs in proximity to the FAP 310. The FAP 310 may
further include a backhaul I/O unit 316 for facilitating
communication with a modem 400, which may be internal or external
to the FAP 310, a controller/processor 315 for controlling and
coordinating the various functionalities of the FAP 310, and a
memory 317 for storing information for utilization by the
controller/processor 315. In related aspects, the transmission
functions of the FAP's WWAN transceiver 311 and WPAN transceiver
313 may be turned off to facilitate operation of the network listen
component 370.
FIG. 4B is a block diagram illustrating an embodiment of a UE 410
according to an exemplary aspect of the disclosure. In FIG. 4B, a
number of blocks are labeled as processors or controllers. Those
skilled in the art will comprehend that each of these processors
may be implemented as hardware processors such as the processor 204
or the processing system 214 illustrated in FIG. 2, or
alternatively, the functions performed by any number of the
illustrated processors may be combined into and implemented by a
single hardware processor. Further, the illustrated processors in
FIG. 4B may represent functions to be implemented by processors,
software, or the like. Here, the UE 410 may include a WWAN
transceiver 420 and WWAN processor 430, as well as a WPAN
transceiver 440 and a WPAN processor 450. Accordingly, the UE 410
may be configured to establish a WWAN link and/or a WPAN link with
the FAP 310. Further, the UE 410 may include an I/O for accepting
user input, for example, from a keypad (not illustrated) and
providing output, for example, to a display (not illustrated).
Further, the UE 410 may include a controller/processor 460 for
controlling the various functions of the UE 410, and a memory 480
for storing information for use by the controller/processor
460.
FIG. 5A is a conceptual diagram illustrating an exemplary system in
which aspects of the present disclosure may be implemented. Here, a
femto cell 510 is located in the general vicinity of a neighboring
macro cell 520. To illustrate the example, two UEs 521, 522 are
camped on the macro cell 520, which concomitantly acts as their
serving cell. The UEs 521, 522 may be configured to receive
downlink transmissions in accordance with scheduling resources
provided by the macro cell 520, and to send uplink transmissions
intended to be received and decoded by the macro cell 520. Since
the antennas of the UEs 521 and 522 may not be directional in
nature, if the UEs 521, 522 are located proximally to the femto
cell 510, the uplink transmissions may be received at the femto
cell 510. Ordinarily, uplink transmissions from the UEs 521, 522
would be considered to be undesirable interference from the
perspective of the WWAN transceiver and the network listen module
of the FAP servicing the femto cell 510. However, in accordance
with some aspects of the present disclosure, the femto cell may
sniff these uplink transmissions to obtain aiding information, such
as to synchronize timing and frequency of the femto cell. In
related aspects, as described in further detail below, the aiding
information may be obtained by a FAP based as least upon aiding
parameters obtained from the UEs 521 and/or 522 via an OOB link
(e.g., a Bluetooth link).
In accordance with aspects of the embodiments described herein, a
FAP of the femto cell 510 may sniff uplink packets transmitted by
UE(s) 521 and/or 522 (e.g., packets directed to the macro cell
520), and may retrieve aiding information, such as, for example,
timing and frequency synchronization information of the particular
macro cell 520 serving the respective UEs 521 and/or 522. That is,
packets transmitted by the UEs 521 and/or 522 directed to
neighboring cells, which otherwise are considered as interference
by a FAP, may be utilized by the FAP to improve the timing and/or
frequency synchronization of the FAP.
In related aspects, the aiding information retrieved by sniffing
the uplink transmissions from UEs may be utilized for refining
coarse timing estimates obtained by other approaches, for example,
utilizing the backhaul I/O module 316, the network listen component
370, or the like, shown in the embodiment of FIG. 3.
In further related aspects, a FAP may sniff packets from UEs that
are transmitting packets. In UMTS, UEs that are transmitting
packets may be in the CELL_FACH or CELL_DCH mode. In other
connected modes, such as the URA_PCH or the CELL_PCH states, the
UEs are not transmitting packets on the uplink. Similarly, in idle
mode, the UEs are also not transmitting packets on the uplink, and
the FAP cannot sniff packets from the UEs in those states.
In order to sniff an uplink packet transmitted by a UE in the
CELL_FACH state, the FAP may utilize scrambling code(s), spreading
code(s), and signature(s) used by the UE in its uplink
transmission(s). For example, the signatures and code numbers may
be included in broadcasted system information (e.g., a given system
information block (SIB)) in a macro cell, and may be obtained by a
network listen entity of the FAP.
That is, to sniff packets from a UE in the CELL_FACH state, the
network listen entity of the FAP may obtain broadcasted system
information (e.g., SIB-5) from the macro cell. With this
information, the FAP may extract signatures (e.g., a signature
index), spreading codes (e.g., orthogonal variable spreading factor
(OVSF) codes), and scrambling codes for the UEs in CELL_FACH from
the broadcasted system information. The FAP may utilize such
information to obtain timing and frequency information from uplink
packets transmitted by the UE(s).
In order to sniff an uplink packet transmitted by an UE in the
CELL_DCH state, the FAP may similarly utilize scrambling code(s),
spreading code(s), and timing offset information used by the UE in
its uplink transmissions. A FAP in the UE's active set will
generally have access to such information, and may utilize this
information to sniff the packets and obtain the timing and
frequency information.
In accordance with aspects of the embodiments described herein,
there are provided techniques for parameter communication for
OOB-based uplink sniffing. As mentioned above, aiding information
for synchronizing the timing and frequency of the FAP may be
obtained by the FAP based as least upon aiding parameters obtained
via an OOB link with UE(s). With reference to the embodiment of
FIG. 5B, there is shown a UE 550 in communication with a FAP 570
via an OOB link 560, which may be a Bluetooth link or the like. The
UE 550 may comprise a WWAN modem 552, a WWAN processor and storage
554, an OOB processor 556, and an OOB modem 558 in operative
communication with each other. The FAP 570 may comprise an OOB
modem 572, an OOB processor 574, a WWAN processor and storage 576,
and a WWAN modem 578 in operative communication with each
other.
At the UE 550, WWAN aiding parameters may be extracted from the
WWAN modem 552 and sent to the WWAN processor and storage 554 to be
stored in registers. The WWAN aiding parameters may be read from
the registers and passed to the OOB processor 556. The OOB aiding
parameters may also optionally be sent to the OOB processor 556
from OOB modem 558. The combined aiding parameters may be sent to
the OOB modem 558. The aiding parameters may be then sent over the
OOB link 560 to the femto OOB modem 572 of the FAP 570. The aiding
parameters may be sent from the femto OOB modem 572 to the OOB
processor 574, which in turn may send the aiding parameters to the
WWAN processor and storage 576. The femto WWAN modem 578 may be
configured to use these aiding parameters in sniffing UE packets
(e.g., uplink packets from the UE to a macro base station).
CELL_FACH: In the CELL_FACH state, the UE may be transmitting a
preamble to gain access to the channel, or transmitting data to the
network. If transmitting a preamble, the UE uses the physical
random access channel (PRACH). UEs in the CELL_FACH state, which
support Release 7 of the 3GPP family of standards and earlier
releases of UMTS, may transmit data only on the PRACH, however, for
later releases the UE may use the enhanced uplink dedicated channel
dedicated physical control channel (E-DPDCH) for transmitting high
data rate uplink messages.
FIG. 6 is a timing diagram that conceptually illustrates some of
the channels discussed herein. In UMTS, the primary common control
physical channel (P-CCPCH) 610 is the timing reference for all
physical channels in a particular cell, directly for the downlink
and indirectly for the uplink. Therefore, in order to obtain the
timing reference of the macro cell, the timing relationship between
the PRACH or the E-DPDCH the UE is using for uplink transmissions
and the P-CCPCH of the macro cell is derived. This timing
relationship is derived from the acquisition indicator channel
(AICH) 620, i.e., the downlink channel carrying the macro cell's
ACK/NAK response to preambles. The AICH 620 has 15 slots labeled
#0-#14, which overlap two P-CCPCH frames including 30 regular
slots. The start of the AICH access slot #0 aligns with the start
of P-CCPCH subframe number (SFN) modulo 2=0.
For each preamble transmitted in an uplink access slot there is a
corresponding access slot from which the UE expects to receive an
ACK/NAK from the network. In the event that an ACK was received,
the timing of the UE's uplink data transmission (called the message
part) is tied to the PRACH and AICH channel timing as shown in FIG.
6. FIG. 7 shows the PRACH 710, the AICH 720, and the access slot
the UE uses for transmission. Here, preambles 715 are 4096 chips
long in slots that are 5120 chips wide. The time difference between
the transmitted preamble and an expected ACK/NAK on the AICH is
depicted as in FIG. 7.
If an ACK 730 is received on the AICH channel 720, then a message
740 of length 10 or 20 ms (data) is transmitted with a time
difference of .tau..sub.p-m from when the original preamble was
sent. If a NAK is received, then another preamble 715 is
transmitted .tau..sub.p-p seconds after the previous preamble 715
was sent. The values for .tau..sub.p-p, .tau..sub.p-m, and
.tau..sub.p-a depend on a parameter called the AICH Transmission
Timing (ATT), which may takes on a value of 0 or 1. The value of
the ATT parameter is derived from the cell broadcast information
and the UE's access service class (ASC). The typical values for
.tau..sub.p-p, .tau..sub.p-m, and .tau..sub.p-a are presented in
Table 1 below.
TABLE-US-00001 TABLE 1 AICH Trans. AICH Trans. Timing = 0 (chips)
Timing = 1 (chips) .tau..sub.p-p, min 15360 20480 .tau..sub.p-a
7680 12800 .tau..sub.p-m 15360 20480
As mentioned above, UEs in the CELL_FACH state supporting Release 8
and beyond are allowed to transmit data with a high data rate on
the E-DPDCH, which may be 2 ms or 10 ms long. The transmission of
E-DPDCH on the uplink 810 relies on the transmission of dedicated
physical control channels, i.e., E-DPCCH and UL DPCCH. When UEs
transmit on the E-DPDCH, the E-DPDCH and E-DPCCH are frame aligned
with UL DPCCH. The UL DPCCH timing is tied to the timing of
downlink channels 820 received during the preamble transmission and
acknowledgement. These timing relationships are illustrated in FIG.
8. Further, the values of the timing parameters illustrated in FIG.
8 are shown in Table 2 below.
The timing relationship between an UE's preamble transmission 830
on the PRACH and acknowledgement 840 on the AICH is the same as
discussed previously, the difference here being when data can be
transmitted after the reception of the ACK 840. After an ACK 840 is
transmitted on the AICH, the Node B transmits control information
to the UE using the fractional dedicated physical channel (F-DPCH).
The F-DPCH is transmitted 10240+256.times.S.sub.offset chips from
the start of the AICH channel. Here, S.sub.offset is an
UE-dependent offset chosen by the network and used in staggering
F-DPCH transmissions to multiple UEs so as to prevent overlaps. The
range of S.sub.offset is shown in Table 2.
TABLE-US-00002 TABLE 2 AICH Trans. AICH Trans. Timing = 0 (chips)
Timing = 1 (chips) .tau..sub.p-p, min 15360 20480 .tau..sub.p-a
7680 12800 .tau..sub.p-m 15360 20480 .tau..sub.a-m 10240 + 256
.times. S.sub.offset + .tau..sub.0 chips .tau..sub.0 1024
S.sub.offset 0, 1, . . . , 9
Once the UE receives the F-DPCH, the UE sends its corresponding
uplink transmission in the UL DPCCH .tau..sub.0 (1024) chips
afterward, as shown in FIG. 9.
While sniffing the UEs' uplink packets in the CELL_FACH state, the
network may determine whether the packet is a PRACH preamble, a
PRACH message, or UL DPCCH (for release 8 and beyond UEs). The FAP
may determine the type of transmission based on the packet
structure of each of the transmissions. The PRACH preamble, PRACH
message, and UL DPCCH structure are discussed below. In related
aspects, the PRACH preambles 1030 are generated by the
multiplication of a preamble signature 1010 with a scrambling code
sequence 1020 as illustrated in FIG. 10.
For example, there may be sixteen possible preamble signatures
available in a particular cell. Each signature is made up of a
16-chip sequence repeated 256 times. While the indices of the
available signatures are typically broadcasted in SIB-5, the subset
available to a particular UE is derived based on the UE's ASC. In
event that the ASC information is not available to the femto
sniffing uplink packets, the femto would have to search through all
sixteen signatures to find the particular signature that was used
by the UE in generating the preamble signal.
The scrambling code used for the PRACH preamble is selected from a
group of 8192 sequences divided into 512 code groups with 16 codes
per group. Hence, the preamble scrambling code can be expressed as
a code with index n, where n=m.times.16+k, where m is the index
identifying the code group with values within the range 0, 1, . . .
, 511 and k, and the specific code number within each group value
is in the range of 0, 1, . . . , 15. The code group index has a
one-to-one relationship with the primary scrambling code used by
the cell (the macro cell in this case). Further information
regarding these codes may be found in 3GPP TS25.213 section
4.3.3.2, incorporated herein by reference. The code number k is
broadcasted in SIB 5.
The PRACH message is made of data and control information masked
with the OVSF spreading and scrambling codes as shown in FIG.
11.
The control part 1110 carries an 8-bit pilot pattern used for
channel estimation at the Node B. There are 14 such patterns
defined 3GPP TS25.211 section 5.2.2.1.3, incorporated herein by
reference. The pilot pattern used in each slot can vary from slot
to slot.
The OVSF code 1120 used for the control part has a fixed spreading
factor of 256 given as C.sub.256,m, where m=16.times.s+15, and s is
the index of the preamble signature, discussed above, which values
ranging from 0, 1, . . . , 15. The OVSF code 1140 for the data part
1130 is based on the spreading factor (SF) used for transmission,
i.e., 256, 128, 64 and 32. The OVSF code 1140 can be expressed as
C.sub.SF,m, where m=SF.times.s/16. Further information about OVSF
codes may be found in 3GPP TS25.213, section 4.3.1.3, incorporated
herein by reference.
The scrambling code 1150 used for the PRACH message part may have a
direct one to one mapping with the scrambling code used in
scrambling the PRACH preamble.
Given that the search space for the data part is higher than the
data, it is recommended that the OVSF code 1120 for the control
part be used in the femto cell search during sniffing. The pilot
sequence could also be employed in the search but since the pilot
sequence can change every slot, it is therefore not efficient to
use the pilot sequences.
FIG. 12 is a block diagram that illustrates UL DPCCH and UL DPDCH
physical layer processing during transmission. It is noteworthy
that although the gain factors are applied during transmissions as
shown in FIG. 12, the FAP may not be required to know the gain
factors during detection.
The UL DPCCH contains control bits such as pilot sequences used for
channel estimation and synchronization. There are six possible
pilot patterns used in the UL DPCCH. The specific pattern used for
transmission is typically signaled to the UE from the network.
The UL DPCCH may be transmitted alone or with other channels such
as the E-DPDCH, E-DPCCH, and UL DPDCH. The transmission of UL DPCCH
1210 with the UL DPDCH 1220 is shown in FIG. 12. The UL DPCCH 1210
may be transmitted on the quadrature component 1230 and spread
using a known OVSF code 1240 with SF 256 and index 0, C.sub.256,0.
After data scaling with the beta factor and combining with the
in-phase component (if transmitted with other channels), the UL
DPCCH 1210 is scrambled using a UE specific scrambling code.
CELL_DCH: In the CELL_DCH state, the UE is actively exchanging data
with the network. Similar to the CELL_FACH state described above,
the timing reference for uplink transmission is the UL DPCCH 1302.
The timing of the UL DPCCH 1302 is derived from the timing of the
DPCH 1310 or the F-DPCH 1320 as shown in FIGS. 13A and 13B,
respectively. Here, the DPCH 1310 and F-DPCH 1320 have
.tau..sub.DPCH and .tau..sub.F-DPCH timing offsets from the cell
P-CCPCH, respectively. Further, the
.tau..sub.DPCH,n=T.sub.n.times.256 chips, and the
.tau..sub.F-DPCH,p=T.sub.p.times.256 chips, where T.sub.n, T.sub.p
is in the range {0, 1, . . . , 149}.
The scrambling code index, beta factors, and .tau..sub.DPCH and
.tau..sub.F-DPCH offsets corresponding to the UL DPCCH are
typically signaled to the UE from the Node B through the Radio
Bearer Configuration (RB Config.) or the Radio Bearer
Reconfiguration (RB Re-config.) message.
Detection Parameters Used for Sniffing: A FAP may sniff uplink
transmissions from UEs to obtain aiding information. The parameters
utilized by the FAP for detection of the uplink transmissions,
possible values of those parameters, and the sources of those
values are presented in Table 3.
TABLE-US-00003 TABLE 3 Detection Parameter Possible Values UE
source of Information UE state CELL_FACH/CELL_DCH Signaled to UE in
the RRC Connection set-up, RB configuration or RB re- configuration
message UE Type Pre-release 5, Release 5, Information is internal
to UE 6, 7, 8, 9 but communicated to the network during UE
capability information exchange PRACH Detection ATT Parameter 0, 1
Obtained from SIB 5/5 bis ASC Parameter 0, 1, . . . , 7 Determined
by UE based information from SIB 5 or 5 bis and USIM information
Preamble signature s = 0, 1, . . . , 15 Available set is signaled
through in SIB 5/5 bis but UE randomly selects a sequence Preamble
Scrambling code 0, 1, . . . , 511 Tied to PSC on serving cell group
signaled. PSC is derived during UE synchronization Preamble code
Number k = 0, 1, . . . , 15 Obtained from SIB 5/5 bis Pilot bit
pattern for the PRACH 14 possible bit patterns Value is signaled
from the message control Part network to UE OVSF code for the PRACH
C.sub.256,m, where m = 16 .times. s + Depends on the selected
message control part 15, and s = 0, 1, . . . , 15 preamble
signature OVSF codes for the PRACH C.sub.SF,m = SF .times. s/16,
where s = SF is chosen by UE based on message data part 0, 1, . . .
, 15, and SF = 32, data rate. 64, 128, 256 s is based on selected
preamble signature UL DPCCH Detection Pilot bit pattern for the UL
6 possible bit patterns Signaled to UE in the RB DPCCH
configuration or RB re- configuration message OVSF code for UL
DPCCH One option - C.sub.256,0 Fixed Scrambling code for UL
2.sup.24 options Signaled to UE in the RB DPCCH configuration or RB
re- configuration message Time offsets - .tau..sub.DPCH and
.tau..sub.F-DPCH .tau..sub.DPCH,n = T.sub.n .times. 256 chip
Signaled to UE in the RB .tau..sub.F-DPCH,p = T.sub.p .times. 256
configuration or RB re- T.sub.n, T.sub.p is in the range {0,
configuration message 1, . . . , 149} S.sub.offset {0, 1, . . . ,
9} Value is signaled from the network to UE
Almost all the parameters presented in Table 3 are provided from
the macro cell to the UE in a broadcast or dedicated message, with
the exception of the preamble signature, which is randomly selected
by the UE. Therefore, the FAP would need to obtain this information
from the UE over the OOB link.
If only a subset of the information is available, then the FAP may
perform an exhaustive search of the possibilities of the unknown
parameters to retrieve the macro cell timing information. Since the
search space of the UL DPCCH scrambling code for the UE is very
large (i.e., 2.sup.24), a system may benefit if the UL DPCCH
detection is used when the UL DPCCH scrambling code of the UE is
known.
Slot and Frame Timing Determination: The detection of the slot or
the frame timing of the P-CCPCH using the PRACH preamble and PRACH
message part in CELL_FACH, UL DPCCH in CELL_FACH and UL DPCCH in
CELL_DCH are illustrated in FIGS. 14-17. In each figure, the order
of the steps used for the determination of the slot timing of the
P-CCPCH is also noted. A flow chart illustrating each of these
detection processes is presented in FIG. 18B. FIG. 18A illustrates
a general process illustrating details of a preliminary procedure
prior to the determination of the slot or the frame timing.
In FIG. 18A, the process depends on the state in which the UE
exists. If the UE is in the CELL_FACH state, then in block 1801,
the process receives detection parameters, for example, utilizing a
backhaul connection to retrieve the information from a network node
such as a neighboring Node B or an RNC. In block 1803, the process
extracts information about the cell from the SIB information
retrieved in block 1801, to be utilized for the reception of uplink
information from the UE as illustrated in FIG. 18B. If the UE is in
the CELL_DCH state, then in block 1805, the process receives
detection parameters, for example, utilizing a backhaul connection
to retrieve the information from a network node such as a
neighboring Node B or an RNC. In block 1807, the process extracts
information about the cell and the UE from the radio bearer message
retrieved in block 1805, to be utilized for the reception of uplink
information from the UE as illustrated in FIG. 18B.
FIG. 14 illustrates the determination of the slot timing of the
P-CCPCH using the PRACH preamble in the CELL_FACH state. FIG. 15
illustrates the determination of the slot timing of the P-CCPCH
using the PRACH message part in the CELL_FACH state. As shown in
FIG. 18B, in block 1802, the process determines whether the cell is
in a CELL_FACH state or a CELL_DCH state. If the process determines
that the UE state is the CELL_FACH state, then the process branches
to block 1804. In block 1804, the process determines whether the UE
is a pre-release-8 UE. If the UE is a pre-release-8 UE, the process
branches to block 1806. In block 1806, the process determines
whether the PRACH preamble or the message part is detected. If the
PRACH preamble or message part is not detected, the process returns
to the start. If the PRACH preamble or message part is detected, as
shown at {circle around (1)} in FIG. 14 or at {circle around (1)}
in FIG. 15; respectively, then the process branches to block 1808.
In block 1808, the process determines the offset from the AICH,
which carries the macro cell's ACK/NAK response to preambles, as
shown at {circle around (2)} in FIG. 14 for the PRACH preamble and
at {circle around (2)} in FIG. 15 for the message part. In block
1810, the process determines the P-CCPCH slot boundary, utilizing
the relationship between the start of the AICH access slot #0 and
the P-CCPCH slots, as shown at {circle around (3)} in FIG. 14 for
the PRACH preamble and at {circle around (3)} in FIG. 15 for the
message part.
As shown in FIG. 18B, in block 1802, if the UE state is determined
to be the CELL_FACH state, the process branches to block 1804. In
block 1804, if the UE is determined not to be a pre-release-8 UE,
the process branches to block 1812. In block 1812, the process
determines whether the PRACH preamble, message part, or UL DPCCH
are detected. If the PRACH preamble, message part, or UL DPCCH are
not detected, the process returns to the start. If the PRACH
preamble, message part, or UL DPCCH are detected, the process
branches to block 1814. In block 1814, the process determines
whether the PRACH preamble or message part are detected. If the
PRACH preamble or message part are detected, the process branches
to block 1818. In block 1818, the process determines the offset
from AICH, which carries the macro cell's ACK/NAK response to
preambles, as shown at {circle around (2)} in FIG. 14 for the PRACH
preamble and at {circle around (2)} in FIG. 15 for the message
part. In block 1820, the process determines the P-CCPCH slot
boundary, utilizing the relationship between the start of the AICH
access slot #0 and the P-CCPCH slots, as shown at {circle around
(3)} in FIG. 14 for the PRACH preamble and at {circle around (3)}
in FIG. 15 for the message part.
FIG. 16 illustrates the determination of the slot timing of the
P-CCPCH using the UL DPCCH in the CELL_FACH state. As shown in FIG.
18B, in block 1802, if the UE state is determined to be the
CELL_FACH state, the process branches to block 1804. In block 1804,
if the UE is determined not to be a pre-release-8 UE, the process
branches to block 1812. In block 1812, the process determines
whether the PRACH preamble, message part, or UL DPCCH are detected.
If the PRACH preamble, message part, or UL DPCCH are not detected,
the process returns to the start. If the PRACH preamble, message
part, or UL DPCCH are detected, the process branches to block 1814.
In block 1814, the process determines whether the PRACH preamble or
message part are detected. If the PRACH preamble and message part
are not detected, the process branches to block 1816. In block
1816, the process determines the offset from F-DPCH, utilizing the
relationship between UL-DPCCH and the F-DPCH, as shown at {circle
around (2)} in FIG. 16. In block 1818, the process determines the
offset from AICH, which carries the macro cell's ACK/NAK response
to preambles, as shown at {circle around (3)} in FIG. 16. In block
1820, the process determines the P-CCPCH slot boundary, utilizing
the relationship between the start of the AICH access slot #0 and
the P-CCPCH slots, as shown at {circle around (4)} in FIG. 16.
FIG. 17 illustrates the determination of the slot and frame timing
of the P-CCPCH using the UL DPCCH in the CELL_DCH state. As shown
in FIG. 18, in block 1802, if the UE state is determined to be the
CELL_DCH state, the process branches to block 1822. In block 1822,
the process determines whether the UL DPCCH is detected, as shown
at {circle around (1)}. If UL DPCCH is not detected, the process
returns to the start. If the UL DPCCH is detected on the downlink,
then in block 1824, as shown at {circle around (2)} in FIG. 17, the
process determines the offset of the DPCH 1310 or the F-DPCH 1320
(see FIGS. 13A and 13B). In block 1826, the process determines the
P-CCPCH frame boundary, as shown at {circle around (3)} in FIG. 17.
In block 1828, the process determines the P-CCPCH slot boundary, as
shown at {circle around (4)} in FIG. 17.
In view of exemplary systems shown and described herein,
methodologies that may be implemented in accordance with the
disclosed subject matter, will be better appreciated with reference
to various flow charts. While, for purposes of simplicity of
explanation, methodologies are shown and described as a series of
acts/blocks, it is to be understood and appreciated that the
claimed subject matter is not limited by the number or order of
blocks, as some blocks may occur in different orders and/or at
substantially the same time with other blocks from what is depicted
and described herein. Moreover, not all illustrated blocks may be
required to implement methodologies described herein. It is to be
appreciated that functionality associated with blocks may be
implemented by software, hardware, a combination thereof or any
other suitable means (e.g., device, system, process, or component).
Additionally, it should be further appreciated that methodologies
disclosed throughout this specification are capable of being stored
on an article of manufacture to facilitate transporting and
transferring such methodologies to various devices. Those skilled
in the art will understand and appreciate that a methodology could
alternatively be represented as a series of interrelated states or
events, such as in a state diagram.
In accordance with one or more aspects of the subject of this
disclosure, there are provided methods for frequency and timing
synchronization of a FAP. With reference to FIG. 19, illustrated is
a methodology 1900 that may be performed by a FAP, or component(s)
thereof. The method 1900 may involve, at 1910, establishing an OOB
link (e.g., Bluetooth link or the like) with at least one UE. The
method 1900 may involve, at 1920, receiving aiding parameters from
the at least one UE via the OOB link. The method 1900 may involve,
at 1930, extracting frequency and timing information from at least
one uplink packet of the at least one UE based at least in part on
the aiding parameters.
With reference to FIG. 20A, there are shown further operations or
aspects of method 1900 that are optional and may be performed by a
FAP for frequency and timing synchronization. It is noted that the
blocks shown in FIGS. 20A-B are not required to perform the method
1900. If the method 1900 includes at least one block of FIGS.
20A-B, then the method 1900 may terminate after the at least one
block, without necessarily having to include any subsequent
downstream block(s) that may be illustrated. It is further noted
that numbers of the blocks do not imply a particular order in which
the blocks may be performed according to the method 1900. For
example, receiving the aiding parameters may involve, at 1940,
receiving information regarding at least one of UE state(s), UE
technology type(s), and channel detection parameter(s) (e.g.,
scrambling codes) from the at least one UE. In the alternative, or
in addition, receiving the aiding parameters may involve, at 1950,
requesting the aiding parameters from the at least one UE via the
OOB link. Extracting the frequency and timing information may
involve, at 1960, sniffing the at least one uplink packet from the
at least one UE to a network entity (e.g., Node B or eNB).
In related aspects, extracting the frequency and timing information
may involve, at 1970, in response to the at least one UE being in a
CELL_FACH state, obtaining via the OOB link information regarding
signatures, spreading codes and scrambling codes for the at least
one UE which the at least one UE received as broadcasted system
information from the macro base station. Extracting may further
involve, at 1972, determining the timing and frequency information
based at least in part on the obtained information.
With reference to FIG. 20B, in further related aspects, extracting
the frequency and timing information may involve, at 1980, in
response to the at least one UE being in a CELL_DCH state,
obtaining information regarding spreading codes, scrambling codes,
and timing offsets based at least in part on the aiding parameters.
Extracting may further involve, at 1982, determining timing and
frequency information based at least in part on the obtained
information. Obtaining may involve, at 1984, obtaining the
information from the at least one UE, in response to the FAP being
in an active set of the at least one UE. In the alternative,
obtaining may involve, at 1986, obtaining the information from the
OOB link, in response to the FAP not being in an active set of the
at least one UE.
In yet further related aspects, sniffing may involve, at 1990, in
response to the macro base station comprising an eNB and the UE
being in a LTE connected mode, monitoring information in at least
one of the LTE channels used by a connected mode LTE UE, a physical
random access channel (PRACH), a demodulation reference signal
(DMRS), and a sounding reference signal (SRS) between the at least
one UE and the macro base station. Sniffing may further involve, at
1992, determining timing and frequency information based at least
in part on the monitored information.
In related aspects, the PRACH parameters may include: (a)
PRACH_Config; (b) PRACH_Mapping; (c) PRACH_PrmbleIndex; (d)
PRACH_RBOffset; (e) PRACH_u; (f) PRACH_Ncs; and/or (g)
PRACH_PwrOffset. Analogously, the PRACH parameters for LTE uplink
signals may include: (a) PRACH configuration index; (b) PRACH
mapping patterns (in FDD, it indicates the subframe number where
the preamble starts; in TDD, it indicates the index of preamble
mapping pattern in time and frequency); (c) preamble indexes (e.g.,
used to select preamble sequences from 64 preambles available in a
given cell); (d) PRACH frequency offset (e.g., the first RB
available for PRACH); (e) logical index of root Zadoff-Chu (ZC)
sequence (u); (f) cyclic shifts of ZC sequence; and/or (g) the
power offset in dB for PRACH.
In further related aspects, the DMRS parameters may include: (a)
physical uplink shared channel (PUSCH) parameters; (b) physical
uplink control channel (PUCCH) parameters; (c) GroupHop_Enable;
and/or (d) SeqHop_Enable. Analogously, the DMRS parameters for LTE
uplink signals may include: (a) PUSCH parameters for LTE uplink
signals; (b) PUCCH parameters for LTE uplink signals; (c) whether
or not to enable group hopping for DMRS on PUCCH and PUSCH; and/or
(d) whether or not to enable sequence hopping for DMRS on PUSCH. It
is noted that not all PUSCH and PUCCH parameters are required for
DMRS. The FAP may try to determine location of DMRS within these
channels by using the difference in correlation properties of DMRS
patterns versus quadrature phase shift keying (QPSK) patterns.
In yet related aspects, the SRS parameters may include: (a) SRS_BW;
(b) SRS_SC Start; (c) SRS_SF_Config; (d) SRS_CS; and/or (e)
SRS_PwrOffset. Analogously, the SRS parameters for LTE uplink
signals may include: (a) the SRS bandwidth in RB; (b) the start
subcarrier of the SRS; (c) SRS subframe configuration; (d) used in
computing the cyclic shift of SRS; and/or (e) the power offset in
dB for SRS.
In accordance with one or more aspects of the subject of this
disclosure, FIG. 21 illustrates a methodology 2100 for FAP
synchronization by a mobile entity (e.g., UE), or component(s)
thereof. The method 2100 may involve, at 2110, determining whether
an OOB link is established with a FAP. The method 2100 may involve,
at 2120, in response to determining that the OOB link is
established, providing aiding parameters to the FAP via the OOB
link. In related aspects, if the UE determines that the OOB link is
not established, the UE may choose to establish that connection by
paging the FAP.
With reference to FIG. 22A, there are shown further operations or
aspects of method 2100 that are optional and may be performed by a
UE for FAP synchronization. It is noted that the blocks shown in
FIGS. 22A-B are not required to perform the method 2100. If the
method 2100 includes at least one block of FIGS. 22A-B, then the
method 2100 may terminate after the at least one block, without
necessarily having to include any subsequent downstream block(s)
that may be illustrated. It is further noted that numbers of the
blocks do not imply a particular order in which the blocks may be
performed according to the method 2100. For example, with reference
to FIG. 22A, providing the aiding parameters may involve, at 2130,
sending information regarding at least one of UE state(s), UE
technology type(s) (e.g., UMTS, LTE, etc.), and channel detection
parameter(s) to the FAP. The method 2100 may further involve, at
2140, sending at least one uplink packet to a network entity.
In related aspects, the method 2100 may further involve, at 2150,
receiving broadcasted system information from the network entity,
in response to the UE being in a CELL_FACH state. The method 2100
may further involve, at 2152, sending the broadcasted system
information to the FAP. Sending may involve, at 2154, sending the
broadcasted system information to the FAP via the OOB link.
In further related aspects, the method 2100 may further involve, at
2160, receiving dedicated signaling information from the network
entity, in response to the UE being in a CELL_DCH state. The method
2100 may further involve, at 2162, providing the signaling
information regarding spreading codes, scrambling codes, and timing
offsets to the FAP over an OOB link.
In yet further related aspects, the method 2100 may further
involve, at 2170, initiating establishment of the OOB link, in
response to determining that the OOB link is not already
established. Providing may involve, at 2180, initiating the
transfer of the aiding parameters to the FAP via the OOB link. In
still further related aspects, the method 2100 may involve, at
2190, in response to determining that the OOB link is not
established, paging the FAP to establish the OOB link.
It is noted that the blocks in FIG. 22A are applicable to UMTS or
LTE. With reference to FIG. 22B, there are provided blocks that are
specific to LTE. For example, the method 2100 may further involve,
at 2210, sending at least one uplink packet to a network entity. In
related aspects, the method 2100 may further involve, at 2220,
receiving broadcasted and/or dedicated system information from the
network entity, in response to the UE being in a LTE connected
state. The method 2100 may further involve, at 2222, sending the
broadcasted system information and/or dedicated signaling
information to the FAP. Sending may involve sending the broadcasted
system information and/or the dedicated signaling information to
the FAP via the OOB link or the like. In further related aspects,
the method 2100 may further involve, at 2230, initiating
establishment of the OOB link, in response to determining that the
OOB link is not already established. Providing may involve, at
2240, initiating the transfer of the aiding parameters to the FAP
via the OOB link.
In accordance with one or more aspects of the embodiments described
herein, there are provided devices and apparatuses for frequency
and timing synchronization of a FAP, as described above with
reference to FIGS. 19-20B. With reference to FIG. 23, there is
provided an exemplary apparatus 2300 that may be configured as a
FAP, or as a processor or similar device for use within the FAP.
The apparatus 2300 may include functional blocks that can represent
functions implemented by a processor, software, or combination
thereof (e.g., firmware).
For example, the apparatus 2300 of FIG. 23 may comprise an
electrical component or module 2302 for establishing an OOB link
with at least one UE. The apparatus 2300 may comprise an electrical
component 2304 for receiving aiding parameters from the at least
one UE via the OOB link. The apparatus 2300 may comprise an
electrical component 2306 for extracting frequency and timing
information from at least one uplink packet of the at least one UE
based at least in part on the aiding parameters.
In related aspects, the apparatus 2300 may optionally include a
processor component 2310 having at least one processor, in the case
of the apparatus 2300 configured as a network entity, rather than
as a processor. The processor 2310, in such case, may be in
operative communication with the components 2302-2306 via a bus
2312 or similar communication coupling. The processor 2310 may
effect initiation and scheduling of the processes or functions
performed by electrical components 2302-2306.
In further related aspects, the apparatus 2300 may include a radio
transceiver component 2314. A stand alone receiver and/or stand
alone transmitter may be used in lieu of or in conjunction with the
transceiver 2314. The apparatus 2300 may optionally include a
component for storing information, such as, for example, a memory
device/component 2316. The computer readable medium or the memory
component 2316 may be operatively coupled to the other components
of the apparatus 2300 via the bus 2312 or the like. The memory
component 2316 may be adapted to store computer readable
instructions and data for effecting the processes and behavior of
the components 2302-2306, and subcomponents thereof, or the
processor 2310, or the methods disclosed herein. The memory
component 2316 may retain instructions for executing functions
associated with the components 2302-2306. While shown as being
external to the processor 2310, the transceiver 2314, and the
memory 2316, it is to be understood that one or more of the
components 2302-2306 can exist within the processor 2310, the
transceiver 2314, and/or the memory 2316.
In accordance with one or more aspects of the embodiments described
herein, there are provided devices and apparatuses (e.g., mobile
entities) configured to facilitate synchronization of a FAP, as
described above with reference to FIGS. 21-22B. With reference to
FIG. 24, the apparatus 2400 may comprise an electrical component or
module 2402 for determining whether an OOB link is established with
a FAP. The apparatus 2400 may comprise an electrical component 2404
for, in response to determining that the OOB link is established,
providing aiding parameters to the FAP via the OOB link. For the
sake of conciseness, the rest of the details regarding apparatus
2400 are not further elaborated on; however, it is to be understood
that the remaining features and aspects of the apparatus 2400 are
substantially similar to those described above with respect to
apparatus 2300 of FIG. 23.
Those of skill in the art would understand that information and
signals may be represented using any of a variety of different
technologies and techniques. For example, data, instructions,
commands, information, signals, bits, symbols, and chips that may
be referenced throughout the above description may be represented
by voltages, currents, electromagnetic waves, magnetic fields or
particles, optical fields or particles, or any combination
thereof.
Those of skill would further appreciate that the various
illustrative logical blocks, modules, circuits, and algorithm steps
described in connection with the disclosure herein may be
implemented as electronic hardware, computer software, or
combinations of both. To clearly illustrate this interchangeability
of hardware and software, various illustrative components, blocks,
modules, circuits, and steps have been described above generally in
terms of their functionality. Whether such functionality is
implemented as hardware or software depends upon the particular
application and design constraints imposed on the overall system.
Skilled artisans may implement the described functionality in
varying ways for each particular application, but such
implementation decisions should not be interpreted as causing a
departure from the scope of the present disclosure.
The various illustrative logical blocks, modules, and circuits
described in connection with the disclosure herein may be
implemented or performed with a general-purpose processor, a
digital signal processor (DSP), an application specific integrated
circuit (ASIC), a field programmable gate array (FPGA) or other
programmable logic device, discrete gate or transistor logic,
discrete hardware components, or any combination thereof designed
to perform the functions described herein. A general-purpose
processor may be a microprocessor, but in the alternative, the
processor may be any conventional processor, controller,
microcontroller, or state machine. A processor may also be
implemented as a combination of computing devices, e.g., a
combination of a DSP and a microprocessor, a plurality of
microprocessors, one or more microprocessors in conjunction with a
DSP core, or any other such configuration.
The steps of a method or algorithm described in connection with the
disclosure herein may be embodied directly in hardware, in a
software module executed by a processor, or in a combination of the
two. A software module may reside in RAM memory, flash memory, ROM
memory, EPROM memory, EEPROM memory, registers, hard disk, a
removable disk, a CD-ROM, or any other form of storage medium known
in the art. An exemplary storage medium is coupled to the processor
such that the processor can read information from, and write
information to, the storage medium. In the alternative, the storage
medium may be integral to the processor. The processor and the
storage medium may reside in an ASIC. The ASIC may reside in a user
terminal. In the alternative, the processor and the storage medium
may reside as discrete components in a user terminal.
In one or more exemplary designs, the functions described may be
implemented in hardware, software, firmware, or any combination
thereof. If implemented in software, the functions may be stored on
or transmitted over as one or more instructions or code on a
computer-readable medium. Computer-readable media includes both
computer storage media and communication media including any medium
that facilitates transfer of a computer program from one place to
another. A storage media may be any available media that can be
accessed by a general purpose or special purpose computer. By way
of example, and not limitation, such computer-readable media can
comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage,
magnetic disk storage or other magnetic storage devices, or any
other medium that can be used to carry or store desired program
code means in the form of instructions or data structures and that
can be accessed by a general-purpose or special-purpose computer,
or a general-purpose or special-purpose processor. Also, any
connection is properly termed a computer-readable medium. For
example, if the software is transmitted from a website, server, or
other remote source using a coaxial cable, fiber optic cable,
twisted pair, digital subscriber line (DSL), or non-transitory
wireless technologies, then the coaxial cable, fiber optic cable,
twisted pair, DSL, or the non-transitory wireless technologies are
included in the definition of medium. Disk and disc, as used
herein, includes compact disc (CD), laser disc, optical disc,
digital versatile disc (DVD), floppy disk and blu-ray disc where
disks usually reproduce data magnetically, while discs reproduce
data optically with lasers. Combinations of the above should also
be included within the scope of computer-readable media.
The previous description of the disclosure is provided to enable
any person skilled in the art to make or use the disclosure.
Various modifications to the disclosure will be readily apparent to
those skilled in the art, and the generic principles defined herein
may be applied to other variations without departing from the
spirit or scope of the disclosure. Thus, the disclosure is not
intended to be limited to the examples and designs described herein
but is to be accorded the widest scope consistent with the
principles and novel features disclosed herein.
* * * * *