U.S. patent application number 15/564872 was filed with the patent office on 2018-04-19 for frequency hopping method for machine type communication.
The applicant listed for this patent is NOKIA SOLUTIONS AND NETWORKS OY. Invention is credited to Nitin MANGALVEDHE, Rapeepat RATASUK, Chun Hai YAO.
Application Number | 20180109286 15/564872 |
Document ID | / |
Family ID | 57073268 |
Filed Date | 2018-04-19 |
United States Patent
Application |
20180109286 |
Kind Code |
A1 |
YAO; Chun Hai ; et
al. |
April 19, 2018 |
FREQUENCY HOPPING METHOD FOR MACHINE TYPE COMMUNICATION
Abstract
A method and apparatus may include receiving, by a machine type
communication user equipment, parameters for frequency hopping in
downlink or uplink. The parameters comprise an "X," `Y," and "Z"
parameters, "X" corresponds to a duration for which the same
physical resource blocks are used for transmission. `Y" corresponds
to a frequency hopping period, and "Z" corresponds to a frequency
hopping pattern indication. The method may also include performing
frequency hopping in accordance with the parameters.
Inventors: |
YAO; Chun Hai; (Beijing,
CN) ; RATASUK; Rapeepat; (Hoffman Estates, IL)
; MANGALVEDHE; Nitin; (Hoffman Estates, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NOKIA SOLUTIONS AND NETWORKS OY |
Espoo |
|
FI |
|
|
Family ID: |
57073268 |
Appl. No.: |
15/564872 |
Filed: |
April 9, 2015 |
PCT Filed: |
April 9, 2015 |
PCT NO: |
PCT/US2015/025138 |
371 Date: |
October 6, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 4/70 20180201; H04B
2001/7154 20130101; H04W 72/042 20130101; H04L 69/323 20130101;
H04B 1/7143 20130101 |
International
Class: |
H04B 1/7143 20060101
H04B001/7143; H04W 4/00 20060101 H04W004/00 |
Claims
1. A method, comprising: receiving, by a machine type communication
user equipment, parameters for frequency hopping in downlink or
uplink, wherein the parameters comprise an "X," "Y," and "Z"
parameters, "X" corresponds to a duration for which the same
physical resource blocks are used for transmission, "Y" corresponds
to a frequency hopping period, and "Z" corresponds to a frequency
hopping pattern indication; and performing frequency hopping in
accordance with the parameters, wherein "X" and "Y" are based on
physical downlink shared channel or machine type communication
downlink control channel or physical uplink shared channel or
physical random access channel repetition levels.
2. The method according to claim 1, wherein the one or more
parameters for frequency hopping are broadcast, configured via
radio resource control signalling or configured via Layer 1 (L1)
signalling.
3. (canceled)
4. The method according to claim 1, wherein "X" is based on a
channel estimation filter length.
5. The method according to claim 1, wherein "Y" corresponds to
ceiling (K/n), "K" corresponds to a number of repetitions, "n" is
an integer greater than or equal to 2, and "n" is the number of
hops in one data transmission configured by an evolved Node B.
6. The method according to claim 1, wherein the values of "X" and
"Y" are the same for all repetition levels, the number of hops is
determined according to the repetition number of the related
repetition level and "Y".
7. The method according to claim 1, wherein "X" corresponds to
Y-1.
8. The method according to claim 1, wherein "Z" is based on an
offset or a predefined pattern for physical downlink shared channel
or machine type communication downlink control channel or physical
uplink shared channel or physical random access channel frequency
hopping.
9. The method according to claim 8, wherein, the predefined pattern
includes half-bandwidth frequency hopping or one-fourth-bandwidth
frequency hopping.
10. The method according to claim 1, wherein "Z" comprises an index
of a pattern of pre-defined PRB blocks, where 6 PRBs constitute a
PRB block, for physical downlink shared channel or physical uplink
shared channel frequency hopping.
11. The method according to claim 1, wherein "Z" comprises an index
of any consecutive 6 PRBs, for physical downlink shared channel or
physical uplink shared channel frequency hopping.
12. The method according to claim 10, wherein a position of
frequency hopping is indicated by DCI, where additional bits
provide the information of the position of the 6 PRBs for each
hop.
13. The method according to claim 1, wherein "Z" is indicated by
higher layer signaling, "Z" is indicated for the physical downlink
shared channel and physical uplink shared channel by the frequency
hopping configuration for the respective channel, and indicated by
the frequency hopping configuration in the random access response
for the machine type communication downlink control channel.
14. An apparatus, comprising: at least one processor; and at least
one memory including computer program code, the at least one memory
and the computer program code configured, with the at least one
processor, to cause the apparatus at least to receive parameters
for frequency hopping in downlink or uplink, wherein the parameters
comprise an "X," "Y," and "Z" parameters, "X" corresponds to a
duration for which the same physical resource blocks are used for
transmission, "Y" corresponds to a frequency hopping period, and
"Z" corresponds to a frequency hopping pattern indication; and
perform frequency hopping in accordance with the parameters,
wherein "X" and "Y" are based on physical downlink shared channel
or machine type communication downlink control channel or physical
uplink shared channel or physical random access channel repetition
levels.
15. The apparatus according to claim 14, wherein the one or more
parameters for frequency hopping are broadcast, configured via
radio resource control signalling or configured via Layer 1 (L1)
signalling.
16. (canceled)
17. The apparatus according to claim 14, wherein "X" is based on a
channel estimation filter length.
18. The apparatus according to claim 14, wherein "Y" corresponds to
ceiling (K/n), "K" corresponds to a number of repetitions, "n"
comprising an integer greater than or equal to 2, and "n" comprises
a number of hops in one data transmission configured by an evolved
Node B.
19. The apparatus according to claim 14, wherein values of "X" and
"Y" are same for all repetition levels, and a number of hops is
determined according to a repetition number of a related repetition
level and "Y".
20. The apparatus according to claim 14, wherein "X" corresponds to
Y-1.
21. The apparatus according to claim 14, wherein "Z" is based on an
offset or a predefined pattern for physical downlink shared channel
or machine type communication downlink control channel or physical
uplink shared channel or physical random access channel frequency
hopping.
22. The apparatus according to claim 21, wherein the predefined
pattern includes half-bandwidth frequency hopping or
one-fourth-bandwidth frequency hopping.
23. The apparatus according to claim 14, wherein "Z" comprises an
index of a pattern of pre-defined PRB blocks, where 6 PRBs
constitute a PRB block, for physical downlink shared channel or
physical uplink shared channel frequency hopping.
24. The apparatus according to claim 14, wherein "Z" comprises an
index of any consecutive 6 PRBs, for physical downlink shared
channel or physical uplink shared channel frequency hopping.
25. The apparatus according to claim 23, wherein a position of
frequency hopping is indicated by DCI, where additional bits
provide information of the position of the 6 PRBs for each hop.
26. The apparatus according to claim 14, wherein "Z" is indicated
by higher layer signaling, "Z" is indicated for the physical
downlink shared channel and physical uplink shared channel by the
frequency hopping configuration for the respective channel, and
indicated by the frequency hopping configuration in the random
access response for the machine type communication downlink control
channel.
27. A computer program product, embodied on a non-transitory
computer readable medium, the computer program product configured
to control a processor to perform a process, comprising: receiving,
by a machine type communication user equipment, parameters for
frequency hopping in downlink and uplink, wherein the parameters
comprise an "X," "Y," and "Z" parameters, "X" corresponds to a
duration for which the same physical resource blocks are used for
transmission, "Y" corresponds to a frequency hopping period, and
"Z" corresponds to a frequency hopping pattern indication; and
performing frequency hopping in accordance with the parameters,
wherein "X" and "Y" are based on physical downlink shared channel
or machine type communication downlink control channel or physical
uplink shared channel or physical random access channel repetition
levels.
28. The computer program product according to claim 27, wherein the
one or more parameters for frequency hopping are broadcast,
configured via radio resource control signalling or configured via
Layer 1 (L1) signalling.
29. (canceled)
30. The computer program product according to claim 27, wherein "X"
is based on a channel estimation filter length.
31. The computer program product according to claim 27, wherein "Y"
corresponds to ceiling (K/n), "K" corresponds to a number of
repetitions, "n" is an integer greater than or equal to 2, and "n"
is the number of hops in one data transmission configured by an
evolved Node B.
32. The computer program product according to claim 1, wherein the
values of "X" and "Y" are the same for all repetition levels, a
number of hops is determined according to the repetition number of
the related repetition level and "Y".
33. The computer program product according to claim 27, wherein "X"
corresponds to Y-1.
34. The computer program product according to claim 27, wherein "Z"
is based on an offset or a predefined pattern for physical downlink
shared channel or machine type communication downlink control
channel or physical uplink shared channel or physical random access
channel frequency hopping.
35. The computer program product according to claim 34, wherein,
the predefined pattern includes half-bandwidth frequency hopping or
one-fourth-bandwidth frequency hopping.
36. The computer program product according to claim 27, wherein "Z"
comprises an index of a pattern of pre-defined PRB blocks, where 6
PRBs constitute a PRB block, for physical downlink shared channel
or physical uplink shared channel frequency hopping.
37. The computer program product according to claim 27, wherein "Z"
is the index of any consecutive 6 PRBs, for physical downlink
shared channel or physical uplink shared channel frequency
hopping.
38. The computer program product according to claim 36, wherein a
position of frequency hopping is indicated by DCI, where additional
bits provide the information of the position of the 6 PRBs for each
hop.
39. The computer program product according to claim 27, wherein "Z"
is indicated by higher layer signaling, "Z" is indicated for the
physical downlink shared channel and physical uplink shared channel
by the frequency hopping configuration for the respective channel,
and indicated by the frequency hopping configuration in the random
access response for the machine type communication downlink control
channel.
Description
BACKGROUND
Field
[0001] Embodiments of the present invention relate to a frequency
hopping method for machine type communication.
Description of the Related Art
[0002] Machine type communication (MTC) is wireless communication
that seeks to communicate with devices by using new
modulation/signal processing techniques. MTC has been described by
the 3th Generation Partnership Project (3GPP), and is based upon
previous network technologies. Since its inception, MTC has seen
extensive deployment in a wide variety of contexts involving the
communication of data.
SUMMARY
[0003] According to a first embodiment, a method may include
receiving, by a machine type communication user equipment,
parameters for frequency hopping in downlink or uplink. The
parameters may include an "X," "Y," and "Z" parameters. "X"
corresponds to a duration for which the same physical resource
blocks are used for transmission. "Y" corresponds to a frequency
hopping period. "Z" corresponds to a frequency hopping pattern
indication. The method may also include performing frequency
hopping in accordance with the parameters.
[0004] In the method of the first embodiment, the one or more
parameters for frequency hopping are broadcast, configured via
radio resource control signalling or configured via Layer 1 (L1)
signalling.
[0005] In the method of the first embodiment, "X" and "Y" are based
on physical downlink shared channel or machine type communication
downlink control channel or physical uplink shared channel or
physical random access channel repetition levels.
[0006] In the method of the first embodiment, "X" is based on a
channel estimation filter length.
[0007] In the method of the first embodiment, "Y" corresponds to
ceiling (K/n), "K" corresponds to a number of repetitions, "n" is
an integer greater than or equal to 2, and "n" is the number of
hops in one data transmission configured by an evolved Node B.
[0008] In the method of the first embodiment, the values of "X" and
"Y" are the same for all repetition levels. The number of hops is
determined according to the repetition number of the related
repetition level and "Y".
[0009] In the method of the first embodiment, "X" corresponds to
Y-1.
[0010] In the method of the first embodiment, "Z" is based on an
offset or a predefined pattern for physical downlink shared channel
or machine type communication downlink control channel or physical
uplink shared channel or physical random access channel frequency
hopping.
[0011] In the method of the first embodiment, the predefined
pattern includes half-bandwidth frequency hopping or
one-fourth-bandwidth frequency hopping.
[0012] In the method of the first embodiment, "Z" is the index of a
pattern of pre-defined PRB blocks, where 6 PRBs constitute a PRB
block, for physical downlink shared channel or physical uplink
shared channel frequency hopping.
[0013] In the method of the first embodiment, "Z" is the index of
any consecutive 6 PRBs, for physical downlink shared channel or
physical uplink shared channel frequency hopping.
[0014] In the method of the first embodiment, the position of
frequency hopping is indicated by DCI, where additional bits
provide the information of the position of the 6 PRBs for each
hop.
[0015] In the method of the first embodiment, "Z" is indicated by
higher layer signaling, more specifically, "Z" is indicated for the
physical downlink shared channel and physical uplink shared channel
by the frequency hopping configuration for the respective channel,
and indicated by the frequency hopping configuration in the random
access response for the machine type communication downlink control
channel.
[0016] According to a second embodiment, an apparatus may include
at least one processor. The apparatus may also include at least one
memory including computer program code. The at least one memory and
the computer program code may be configured, with the at least one
processor, to cause the apparatus at least to receive parameters
for frequency hopping in downlink or uplink. The parameters
comprise an "X," "Y," and "Z" parameters. "X" corresponds to a
duration for which the same physical resource blocks are used for
transmission. "Y" corresponds to a frequency hopping period. "Z"
corresponds to a frequency hopping pattern indication. The
apparatus may also be caused to perform frequency hopping in
accordance with the parameters.
[0017] In the apparatus of the second embodiment, the one or more
parameters for frequency hopping are broadcast, configured via
radio resource control signalling or configured via Layer 1 (L1)
signalling.
[0018] In the apparatus of the second embodiment, "X" and "Y" are
based on physical downlink shared channel or machine type
communication downlink control channel or physical uplink shared
channel or physical random access channel repetition levels.
[0019] In the apparatus of the second embodiment, "X" is based on a
channel estimation filter length.
[0020] In the apparatus of the second embodiment, "Y" corresponds
to ceiling (K/n). "K" corresponds to a number of repetitions. "n"
is an integer greater than or equal to 2, and "n" is the number of
hops in one data transmission configured by an evolved Node B.
[0021] In the apparatus of the second embodiment, the values of "X"
and "Y" are the same for all repetition levels. The number of hops
is determined according to the repetition number of the related
repetition level and "Y".
[0022] In the apparatus of the second embodiment, "X" corresponds
to Y-1.
[0023] In the apparatus of the second embodiment, "Z" is based on
an offset or a predefined pattern for physical downlink shared
channel or machine type communication downlink control channel or
physical uplink shared channel or physical random access channel
frequency hopping.
[0024] In the apparatus of the second embodiment, the predefined
pattern includes half-bandwidth frequency hopping or
one-fourth-bandwidth frequency hopping.
[0025] In the apparatus of the second embodiment, "Z" is the index
of a pattern of pre-defined PRB blocks, where 6 PRBs constitute a
PRB block, for physical downlink shared channel or physical uplink
shared channel frequency hopping.
[0026] In the apparatus of the second embodiment, "Z" is the index
of any consecutive 6 PRBs, for physical downlink shared channel or
physical uplink shared channel frequency hopping.
[0027] In the apparatus of the second embodiment, the position of
frequency hopping is indicated by DCI, where additional bits
provide the information of the position of the 6 PRBs for each
hop.
[0028] In the apparatus of the second embodiment, "Z" is indicated
by higher layer signaling, more specifically, "Z" is indicated for
the physical downlink shared channel and physical uplink shared
channel by the frequency hopping configuration for the respective
channel, and indicated by the frequency hopping configuration in
the random access response for the MTC downlink control
channel.
[0029] According to a third embodiment, a computer program product
may be embodied on a non-transitory computer readable medium. The
computer program product may be configured to control a processor
to perform a process, including receiving, by a machine type
communication user equipment, parameters for frequency hopping in
downlink and uplink. The parameters may include an "X," "Y," and
"Z" parameters. "X" corresponds to a duration for which the same
physical resource blocks are used for transmission. "Y" corresponds
to a frequency hopping period. "Z" corresponds to a frequency
hopping pattern indication. The process may also include performing
frequency hopping in accordance with the parameters.
[0030] In the computer program product of the third embodiment, the
one or more parameters for frequency hopping are broadcast,
configured via radio resource control signalling or configured via
Layer 1 (L1) signalling.
[0031] In the computer program product of the third embodiment, "X"
and "Y" are based on physical downlink shared channel or machine
type communication downlink control channel or physical uplink
shared channel or physical random access channel repetition
levels.
[0032] In the computer program product of the third embodiment, "X"
is based on a channel estimation filter length.
[0033] In the computer program product of the third embodiment, "Y"
corresponds to ceiling (K/n). "K" corresponds to a number of
repetitions. "n" is an integer greater than or equal to 2, and "n"
is the number of hops in one data transmission configured by an
evolved Node B.
[0034] In the computer program product of the third embodiment, the
values of "X" and "Y" are the same for all repetition levels, the
number of hops is determined according to the repetition number of
the related repetition level and "Y".
[0035] In the computer program product of the third embodiment, "X"
corresponds to Y-1.
[0036] In the computer program product of the third embodiment, "Z"
is based on an offset or a predefined pattern for physical downlink
shared channel or machine type communication downlink control
channel or physical uplink shared channel or physical random access
channel frequency hopping.
[0037] In the computer program product of the third embodiment, the
predefined pattern includes half-bandwidth frequency hopping or
one-fourth-bandwidth frequency hopping.
[0038] In the computer program product of the third embodiment, "Z"
is the index of a pattern of pre-defined PRB blocks, where 6 PRBs
constitute a PRB block, for physical downlink shared channel or
physical uplink shared channel frequency hopping.
[0039] In the computer program product of the third embodiment, "Z"
is the index of any consecutive 6 PRBs, for physical downlink
shared channel or physical uplink shared channel frequency
hopping.
[0040] In the computer program product of the third embodiment, the
position of frequency hopping is indicated by DCI, where additional
bits provide the information of the position of the 6 PRBs for each
hop.
[0041] In the computer program product of the third embodiment, "Z"
is indicated by higher layer signaling, more specifically, "Z" is
indicated for the physical downlink shared channel and physical
uplink shared channel by the frequency hopping configuration for
the respective channel, and indicated by the frequency hopping
configuration in the random access response for the MTC downlink
control channel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] For proper understanding of the invention, reference should
be made to the accompanying drawings, wherein:
[0043] FIG. 1 illustrates a frequency hopping frequency and
configuration.
[0044] FIG. 2 illustrates frequency hopping with half-system
bandwidth.
[0045] FIG. 3 illustrates frequency hopping with a physical
resource blocks (PRBs) pattern.
[0046] FIG. 4 illustrates a flowchart of a method in accordance
with certain embodiments of the invention.
[0047] FIG. 5 illustrates an apparatus in accordance with certain
embodiments of the invention.
[0048] FIG. 6 illustrates an apparatus in accordance with certain
embodiments of the invention.
DETAILED DESCRIPTION
[0049] Certain embodiments of the present invention relate to a
frequency hopping method for machine type communication. Certain
embodiments of the present invention relate to the 3GPP Release 13
Work Item entitled "Further LTE Physical Layer Enhancements for
MTC." One of the objectives of certain embodiments is to improve
coverage enhancement. Another objective may be to implement related
techniques such as frequency hopping, for example.
[0050] In RAN1#79 meeting, it was agreed that Release 13 low-cost
machine type communications (MTC) user equipment (UE) can only
transmit and receive data in a narrow bandwidth (such as a
bandwidth of 6 physical resource blocks (PRBs), for example).
[0051] As shown by contribution R1-150255, for the event timer unit
channel 1 (ETU1 channel), the gain from hopping is negligible at a
10% block error rate (BLER) point. At the 1% BLER point, there is a
gain of up to 1 dB. Such a gain may result in up to a 25% reduction
in the number of required repetitions for this channel.
[0052] Hence, frequency hopping may be a promising technique for
further consideration. For improvement of physical uplink shared
channel coverage, R1-150254 has provided a similar observation.
R1-150254 has described the following: "Observation 2: For PUSCH,
cross-subframe channel estimation reduces the number of required
repetitions significantly. At high coverage enhancement level,
increased DMRS density and PSD boosting below 1 PRB can also reduce
the number of required repetitions significantly. Frequency hopping
is also promising techniques but requires further study." As such,
frequency hopping may be a promising technique for enhancing
coverage for physical uplink shared channel (PUSCH) and for
physical downlink shared channel (PDSCH).
[0053] In RAN1#80 meeting, the following agreements were reached,
as described below. PDSCH and PUSCH frequency hopping will be
supported when MTC user equipment (UE) is located in enhanced
coverage. With regard to the reached agreements, for Release 13 low
complexity UE in enhanced coverage, the following techniques that
are related to, at least, unicast PDSCH should be supported.
[0054] In order to allow cross-subframe channel estimation, the
scheduled PRB is in the same (frequency domain) position during at
least X subframes. Assuming that the channel does not vary
significantly during those X subframes, the channel for that PRB
can be estimated by using reference symbols in all X subframes with
the help of an appropriate filter. The value of "X" and the
configuration are intended to be studied further. Having the PRB
position as the same for X subframes does not preclude
discontinuous transmission for unicast PDSCH.
[0055] Frequency hopping is supported over the system bandwidth
(BW). If/when frequency hopping is applied, a frequency location
should be switched after every Y consecutive subframes, where Y is
equal to or larger than X, assuming that a re-tuning time is
included in Y. Configurability is intended to be studied
further.
[0056] With regard to other agreements that are reached, for
physical channel(s) carrying UL data repetition (including
different redundancy versions (RVs)) for Release 13 low complexity
MTC UEs with a coverage enhancement mode, a variety of techniques
are supported. For example, the following techniques are supported:
(1) Cross-subframe channel estimation, and/or (2) Frequency hopping
over system bandwidth across subframes. The network can enable or
disable the hopping. The details of configuration are intended to
be studied further.
[0057] It was agreed that Release 13 low cost MTC UE can only
transmit and receive data in a narrow bandwidth (such as a
bandwidth of 6 PRBs, for example). Considering the agreements of
RAN1#80 meeting, PDSCH and PUSCH for MTC could change the frequency
domain location in different subframes. Several issues related to
frequency hopping may need to be addressed. For example, frequency
hopping patterns for UL and DL physical channels may need to be
addressed. Frequency hopping configurations in UL and DL may need
to be addressed.
[0058] Based on the RAN1#80 agreements, frequency hopping patterns
and configurations can be described by three parameters as
illustrated by FIG. 1. FIG. 1 illustrates a frequency hopping
frequency and configuration.
[0059] The parameters are described as follows. "X" may correspond
to a duration of same PRB position (to enable cross-subframe
channel estimation), and the unit of measurement may be a subframe.
"Y" may correspond to a frequency hopping period (equal to or
greater than X, including a re-tuning time), and the unit of
measurement may be a subframe. "Z" may correspond to a frequency
hopping pattern indication.
[0060] Certain embodiments of the present invention may be directed
to the configuration of (X, Y, Z) parameters for frequency hopping
in DL and UL.
[0061] With respect to X & Y configuration, X and Y are based
on the
Enhanced-Physical-Downlink-Control-Channel/Physical-Downlink-Shared-Chann-
el or Physical-Uplink-Shared-Channel/Physical-Random-Access-Channel
repetition level, or based on a coverage enhancement level in UL
and DL. The repetition level is configured by the eNB and each
transmission is repeated a pre-defined number of times for each
repetition level. The maximum values of X and Y should be less than
the number of repetitions configured for the UE.
[0062] Y depends on a channel estimation filter length to allow UE
to start cross-subframe channel estimation prior to PDSCH/PUSCH
transmission by the eNB. Cross-subframe channel estimation also
depends on the phase continuity at the eNB/UE. So, in one
embodiment, Y can depend on the assumed phase continuity at the
eNB/UE. In one embodiment, Y=ceiling(K/n), where K=number
ofrepetition, and "n" is an integer greater than or equal to 2. "n"
is a parameter configured by the eNB. There may be one parameter
"n" that can be used to calculate X and Y, regardless of the
repetition level. In other words, if MTC knows the repetition
numbers of all repetition levels, the X and Y will update
automatically if a repetition level is adjusted. This is more
suitable for the case that frequency hopping pattern is indicated
by DCI.
[0063] With a second embodiment for X and Y configuration, the
values of X and Y are the same for all repetition levels and, with
the information of configured maximum repetition number for the
repetition level, an MTC UE can derive the number of frequency hops
via dividing the repetition number by Y. If repetition level
adaptation is allowed, the eNB needs to inform the UE the
repetition numbers corresponding to all repetition levels;
therefore, UE could simply adjust the number of frequency hops when
the repetition level is updated, in case the half-system-bandwidth
frequency hopping pattern is applied
[0064] The value of X may correspond to Y-1, for example, when the
re-tuning time does not exceed a subframe duration. In another
embodiment, the initial X and Y are based on a preamble repetition
level that is used in a random access procedure. During an initial
system access, the preamble repetition level is used as a starting
point for a UE coverage enhancement level.
[0065] With respect to Hopping Pattern Z, with a first embodiment,
when an eNB schedules a coverage enhancement MTC UE, the UE can be
scheduled in any continuous 6 PRBs.
[0066] In DL, frequency hopping of enhanced physical downlink
control channel (EPDCCH) and PDSCH is implemented by switching a
fixed frequency position, for example, switching by half of the
system bandwidth or one-fourth of the system bandwidth. More
specifically, for half-bandwidth frequency hopping, the PRB
position after frequency hopping is determined by adding a
half-system-bandwidth with the PRB position prior to the hopping
and wrapping around to remain inside the system bandwidth.
n PRB hopping = { ( n first PRB + N RB DL / 2 ) mod N RB DL if ( n
first PRB + N RB DL / 2 ) mod N RB DL .ltoreq. N RB DL - 6 ( n
first PRB + N RB DL / 2 ) mod N RB DL - 3 if N RB DL - 6 < ( n
first PRB + N RB DL / 2 ) mod N RB DL .ltoreq. N RB DL - 3 n first
PRB + N RB DL / 2 ) mod N RB DL + 3 if N RB DL - 3 < ( n first
PRB + N RB DL / 2 ) mod N RB DL .ltoreq. N RB DL ##EQU00001##
[0067] N.sub.RB.sup.DL is a system bandwidth, expressed in multiple
of PRB. n.sub.first PRB is the first PRB index of a continuous 6
PRBs before the frequency hopping. n.sub.PRB hopping is the first
PRB index of a continuous 6 PRBs after the frequency hopping.
[0068] In UL, the PUSCH or physical random access channel (PRACH)
frequency hopping is similar to PDSCH frequency hopping, and only
the PRBs allocated to PUCCH are precluded from system bandwidth to
avoid collision with PUCCH PRBs.
[0069] The frequency hopping pattern can be determined as
n PRB hopping = { ( n first PRB + N RB DL / 2 - N RB PUCCH ) mod (
N RB DL - 2 N RB PUCCH ) if ( n first PRB + N RB DL / 2 - N RB
PUCCH ) mod ( N RB DL - 2 N RB PUCCH ) - 3 .ltoreq. N RB DL - 2 N
RB PUCCH - 6 ( n first PRB + N RB DL / 2 - N RB PUCCH ) mod ( N RB
DL - 2 N RB PUCCH ) - 3 if N RB DL - 2 N RB PUCCH - 6 < ( n
first PRB + N RB DL / 2 - N RB PUCCH ) mod ( N RB DL - 2 N RB PUCCH
) - 3 .ltoreq. N RB DL - 2 N RB PUCCH ( n first PRB + N RB DL / 2 -
N RB PUCCH ) mod ( N RB DL - 2 N RB PUCCH ) + 3 else
##EQU00002##
N.sub.RB.sup.PUCCH are the PRB numbers allocated for PUCCH
transmission in half of the system bandwidth.
[0070] Frequency hopping of EPDCCH, PDSCH, and PUSCH can be
configured separately by higher layer signalling. The frequency
location of physical channels can be switched several times
according to the configured repetition level. Enabling of frequency
hopping can be indicated by higher layer signalling, such as by
Random Access Response (RAR) or by physical layer signalling. For
example, enabling of frequency hopping can be signalled by, for
example, 1 bit in downlink control information (DCI). For PRACH,
frequency-hopping-related information is embedded in the PRACH
configuration, including whether frequency hopping is enabled or
not, X or Y value indication, and frequency hopping pattern
indication such as half-system bandwidth frequency hopping or
one-fourth bandwidth frequency hopping. The PUCCH PRBs are excluded
from the system bandwidth. Some potential specification impacts on
TS36.331 are shown below. Here, it is assumed that the number of
repetitions for each repetition level is already defined.
TABLE-US-00001 PRACH-Config information elements -- ASN1START
PRACH-ConfigSIB ::= SEQUENCE { rootSequenceIndex INTEGER (0..837),
prach-ConfigInfo PRACH-ConfigInfo } PRACH-Config ::= SEQUENCE {
rootSequenceIndex INTEGER (0..837), prach-ConfigInfo
PRACH-ConfigInfo OPTIONAL -- Need ON } PRACH-ConfigInfo ::=
SEQUENCE { prach-ConfigIndex INTEGER (0..63), highSpeedFlag
BOOLEAN, zeroCorrelationZoneConfig INTEGER (0..15),
prach-FreqOffset INTEGER (0..94) frequency hopping enabling BOOLEAN
frquency hopping period INTERGER (0..63) frquency hopping pattern
INTERGER (0,1) } } -- ASN1STOP
[0071] The pattern may also include an offset that depends on a
physical cell ID (PCI) to randomize inter-cell interference.
[0072] With a second embodiment, a MTC UE can only be scheduled
within predefined 6-PRB regions, according to the system bandwidth.
The UL or DL PRB(s) position (after each frequency hopping) is
signalled in DCI carried by EPDCCH (when scheduling PDSCH or
PUSCH). Alternatively, the frequency hopping information can be
carried by higher layer signalling with PDSCH or PUSCH
configuration. The frequency hopping information may include the
initial 6 PRBs position and duration, the 6 PRBs position in a
first frequency hopping and duration, and so on. For EPDCCH
frequency hopping, the PRB(s) position indication can be configured
for the UE, in terms of the operating 6-PRB allocation, by higher
layer signalling, such as RAR signalling.
[0073] With a third embodiment, MTC UE can be scheduled in any
continuous 6 PRBs in the system bandwidth. The UL or DL PRB(s)
position after frequency hopping is signaled in DCI carried by
EPDCCH (scheduling PDSCH or PUSCH). Alternatively, the frequency
hopping information can be carried by higher layer signalling with
PDSCH or PUSCH configuration, such as the initial 6 PRBs position
and duration, 6 PRBs position in first frequency hopping and
duration, and so on. For EPDCCH frequency hopping, the PRB position
indication can be configured for the UE, in terms of the operating
6-PRB allocation, by higher layer signalling such as RAR
signalling.
[0074] Further, with certain embodiments of the present invention,
when hopping is applied on one link (DL or UL), the same pattern is
also simultaneously applied on the other link. In case UE needs to
maintain the same Tx-Rx separation, certain embodiments may
synchronize hopping.
[0075] Certain embodiments of the present invention implement UL
and DL frequency hopping for low cost MTC in coverage mode.
[0076] With respect to X & Y Configuration, configuration of X
& Y may be straightforward.
[0077] In one embodiment, X and Y may be based on a EPDCCH/PDSCH
repetition level, a PUSCH/PRACH repetition level, or based on a
configured coverage enhancement level in UL and DL. In another
embodiment, X and Y are separately configured for EPDCCH, PDSCH,
PUSCH, and PRACH.
[0078] In another embodiment, X and Y can either be semi-statically
configured, dynamically assigned, and/or derived from another
transmission. For example, X & Y for Msg3 transmission can be
derived from the number of PRACH repetitions.
[0079] In another embodiment, X and Y are dependent on the type of
transmission. For example, X & Y could be different for a RAR,
Paging, unicast, System Information Block (SIB), or broadcast
channel.
[0080] In another embodiment, Y=ceiling(K/n), where K=number of
repetitions, and n is an integer greater than or equal to 2 (that
is configured by eNB).
[0081] One parameter "n" can be specified that can be used to
calculate X and Y, regardless of the repetition level. In other
words, the X and Y values may update automatically if the
repetition level is adjusted.
[0082] With respect to Hopping Pattern Z, in one embodiment,
frequency hopping is based on an offset or a predefined pattern. In
another embodiment, the offset is based on the system bandwidth, is
provided in the DCI, is based on a physical cell ID, and/or is
configured via higher layer signalling.
[0083] In another embodiment, the predefined pattern may be based
on a system bandwidth or a physical cell ID, and the hopping
information may be configured via higher layer signalling.
[0084] In one embodiment, when hopping is applied on one link (DL
or UL), the same pattern is also simultaneously applied on the
other link.
[0085] With a first embodiment, the MTC UE can be scheduled in any
6 continuous PRBs by eNB, if frequency hopping is enabled. After
repeated transmission with a predefined number of repetitions in
the same 6 PRBs, the MTC UE may transmit or receive in another 6
PRBs. The frequency location may be shifted by half the system
bandwidth. For instance, if the system bandwidth is 100 PRBs and
the PDSCH is initially transmitted in PRB #5-12, then after the
frequency hopping, the PDSCH will be transmitted in PRB #55-62.
Also, frequency hopping can be performed several times according to
a repetition level. Then, after another frequency hopping, the
PDSCH will be transmitted again in PRB #5-12.
[0086] FIG. 2 illustrates frequency hopping with a
half-system-bandwidth. As illustrated by FIG. 2, with repetition
level 2, frequency hopping is performed twice. Also according to
these embodiments, the frequency hopping configuration can be
different for different MTC UEs.
[0087] With this embodiment, different MTC UEs (or UEs in different
repetition levels) could get the most of the frequency diversity
gains. It may be easier for MTC UE implementation.
[0088] With a second embodiment of the present invention, the
available 6 PRBs for MTC UE is determined according to the center 6
PRBs. The central 6 PRBs may be used for PBCH/SIB/Paging reception,
and the 6 PRBs allocated to MTC UE are not overlapped with the
center 6 PRBs. If the system bandwidth is 20 MHz (corresponding to
100 PRBs, for example), each half of the bandwidth could have 47
PRBs available for MTC usage. 7.times.6 PRBs can be allocated to
MTC UEs, and 5 PRBs may not be used within the half-bandwidth. So,
there are a total of 15 (7+1+7) PRB blocks for MTC usage. With
these embodiments, 4 bits are needed to indicate the frequency
location of 6 PRBs for each hopping. The 4.times.m bits of hopping
information can be included in DCI (carried by EPDCCH), where m is
the number of hops for one data transmission. If frequency hopping
information is accompanying an indication of MTC operating PRBs,
the hopping information could comprise {initial 6 PRBs position, 6
PRBs position in first hopping, 6 PRBs position in second hopping .
. . }. In another way, the 6-PRB allocation does not depend on
isolating the central 6 PRBs; for example, if 6 PRBs constitute a
PRB block, there are at most 16 PRB blocks available for MTC usage,
and again 4 bits are needed in DCI for each frequency hopping.
[0089] For this embodiment, the frequency position for each hopping
in one data transmission can be flexibly determined by the eNB.
However, the available PRBs for MTC usage are less than the first
embodiment and more DCI bits are required for frequency hopping.
The illustration of a second embodiment is illustrated by FIG. 3.
FIG. 3 illustrates frequency hopping with a PRBs pattern.
[0090] With a third embodiment, there may be no PRBs allocation
restrictions for MTC, the first PRB index of the allocated PRB
block can be flexibly configured by the eNB. However, more bits in
DCI are required to indicate the PRB position after the hopping.
The eNB has more flexibility to scheduling MTC UE and hopping. But,
with an increase in MTC devices, the eNB scheduling could get more
complex and the frequency diversity gain will decrease.
[0091] For the frequency hopping period and duration determination,
certain embodiments of the present invention may be robust and
automatically adapted to implicitly update a repetition level, and
additional Radio Resource Control (RRC) signaling may not be
required.
[0092] For the frequency hopping patterns, the first embodiment has
little impact on standards, while most of frequency diversity gains
can be achieved.
[0093] The second embodiment may allow the eNB to have more
flexibility to configure the frequency position location. The cost
could be an increase in DCI size, and the EPDCCH transmission may
need more repetition.
[0094] The third embodiment may be more flexible than the second
embodiment, but the third embodiment may need to add more bits in
DCI.
[0095] FIG. 4 illustrates a flowchart of a method in accordance
with certain embodiments of the invention. The method illustrated
in FIG. 4 includes, at 410, receiving, by a machine type
communication user equipment, parameters for frequency hopping in
downlink or uplink. The parameters comprise an "X," "Y," and "Z"
parameters. "X" corresponds to a duration for which the same
physical resource blocks are used for transmission. "Y" corresponds
to a frequency hopping period, and "Z" corresponds to a frequency
hopping pattern indication. The method may also include, at 420,
performing frequency hopping in accordance with the parameters.
[0096] FIG. 5 illustrates an apparatus in accordance with certain
embodiments of the invention. In one embodiment, the apparatus can
be a user equipment, a base station, and/or a MTC device, for
example. The apparatus can be a network node. Apparatus 10 can
include a processor 22 for processing information and executing
instructions or operations. Processor 22 can be any type of general
or specific purpose processor. While a single processor 22 is shown
in FIG. 5, multiple processors can be utilized according to other
embodiments. Processor 22 can also include one or more of
general-purpose computers, special purpose computers,
microprocessors, digital signal processors (DSPs),
field-programmable gate arrays (FPGAs), application-specific
integrated circuits (ASICs), and processors based on a multi-core
processor architecture, as examples.
[0097] Apparatus 10 can further include a memory 14, coupled to
processor 22, for storing information and instructions that can be
executed by processor 22. Memory 14 can be one or more memories and
of any type suitable to the local application environment, and can
be implemented using any suitable volatile or nonvolatile data
storage technology such as a semiconductor-based memory device, a
magnetic memory device and system, an optical memory device and
system, fixed memory, and removable memory. For example, memory 14
include any combination of random access memory (RAM), read only
memory (ROM), static storage such as a magnetic or optical disk, or
any other type of non-transitory machine or computer readable
media. The instructions stored in memory 14 can include program
instructions or computer program code that, when executed by
processor 22, enable the apparatus 10 to perform tasks as described
herein.
[0098] Apparatus 10 can also include one or more antennas (not
shown) for transmitting and receiving signals and/or data to and
from apparatus 10. Apparatus 10 can further include a transceiver
28 that modulates information on to a carrier waveform for
transmission by the antenna(s) and demodulates information received
via the antenna(s) for further processing by other elements of
apparatus 10. In other embodiments, transceiver 28 can be capable
of transmitting and receiving signals or data directly.
[0099] Processor 22 can perform functions associated with the
operation of apparatus 10 including, without limitation, precoding
of antenna gain/phase parameters, encoding and decoding of
individual bits forming a communication message, formatting of
information, and overall control of the apparatus 10, including
processes related to management of communication resources.
[0100] For example, apparatus 10 may receive parameters for
frequency hopping in downlink or uplink. The parameters may include
an "X," "Y," and "Z" parameters. "X" may correspond to a duration
for which the same physical resource blocks are used for
transmission. "Y" may correspond to a frequency hopping period. "Z"
may correspond to a frequency hopping pattern indication. Apparatus
10 may also perform frequency hopping in accordance with the
parameters.
[0101] In an embodiment, memory 14 can store software modules that
provide functionality when executed by processor 22. The modules
can include an operating system 15 that provides operating system
functionality for apparatus 10. The memory can also store one or
more functional modules 18, such as an application or program, to
provide additional functionality for apparatus 10. The components
of apparatus 10 can be implemented in hardware, or as any suitable
combination of hardware and software.
[0102] FIG. 6 illustrates an apparatus in accordance with certain
embodiments of the invention. Apparatus 600 can be a network
element/entity such as a user equipment, for example. Apparatus 600
can include a receiving unit 610 that receives, by a machine type
communication user equipment, parameters for frequency hopping in
downlink or uplink, wherein the parameters comprise an "X," "Y,"
and "Z" parameters, "X" corresponds to a duration for which the
same physical resource blocks are used for transmission. "Y"
corresponds to a frequency hopping period, and "Z" corresponds to a
frequency hopping pattern indication. Apparatus 600 can also
include a performing unit 620 that performs frequency hopping in
accordance with the parameters.
[0103] The described features, advantages, and characteristics of
the invention can be combined in any suitable manner in one or more
embodiments. One skilled in the relevant art will recognize that
the invention can be practiced without one or more of the specific
features or advantages of a particular embodiment. In other
instances, additional features and advantages can be recognized in
certain embodiments that may not be present in all embodiments of
the invention. One having ordinary skill in the art will readily
understand that the invention as discussed above may be practiced
with steps in a different order, and/or with hardware elements in
configurations which are different than those which are disclosed.
Therefore, although the invention has been described based upon
these preferred embodiments, it would be apparent to those of skill
in the art that certain modifications, variations, and alternative
constructions would be apparent, while remaining within the spirit
and scope of the invention.
* * * * *