U.S. patent application number 14/126020 was filed with the patent office on 2014-11-27 for control channel design for new carrier type (nct).
The applicant listed for this patent is Xiaogang Chen, Jong-Kae Fwu, Seunghee Han, Yuan Zhu. Invention is credited to Xiaogang Chen, Jong-Kae Fwu, Seunghee Han, Yuan Zhu.
Application Number | 20140348077 14/126020 |
Document ID | / |
Family ID | 50825387 |
Filed Date | 2014-11-27 |
United States Patent
Application |
20140348077 |
Kind Code |
A1 |
Chen; Xiaogang ; et
al. |
November 27, 2014 |
CONTROL CHANNEL DESIGN FOR NEW CARRIER TYPE (NCT)
Abstract
Technology for allocating at least one physical resource block
(PRB) for an Enhanced Physical Hybrid-ARQ Indicator Channel
(EPHICH) transmission for a New Carrier Type (NCT) is disclosed. In
one method, a number of bits associated with channel coding for an
acknowledgement (ACK) or negative acknowledgement (NACK) in the
EPHICH transmission is determined. A plurality of modulation
symbols for each ACK or NACK in the EPHICH transmission is
generated based in part on the number of bits associated with the
ACK or NACK. The plurality of modulation symbols are mapped as
EPHICH quadrants in one or more resource element blocks (REGs),
wherein the EPHICH quadrants are mapped to a plurality of physical
resource blocks (PRBs) allocated for EPHICH to increase frequency
diversity gain.
Inventors: |
Chen; Xiaogang; (Beijing,
CN) ; Han; Seunghee; (Anyangshi, KR) ; Zhu;
Yuan; (Beijing, CN) ; Fwu; Jong-Kae;
(Sunnyvale, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Chen; Xiaogang
Han; Seunghee
Zhu; Yuan
Fwu; Jong-Kae |
Beijing
Anyangshi
Beijing
Sunnyvale |
CA |
CN
KR
CN
US |
|
|
Family ID: |
50825387 |
Appl. No.: |
14/126020 |
Filed: |
September 27, 2013 |
PCT Filed: |
September 27, 2013 |
PCT NO: |
PCT/US2013/062180 |
371 Date: |
December 13, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61732851 |
Dec 3, 2012 |
|
|
|
Current U.S.
Class: |
370/329 |
Current CPC
Class: |
H04W 72/1242 20130101;
H04W 92/18 20130101; H04W 72/1205 20130101; Y02D 70/1226 20180101;
Y02D 70/164 20180101; H04L 25/0202 20130101; H04W 24/02 20130101;
Y02D 30/70 20200801; Y02D 70/1224 20180101; H04L 1/1854 20130101;
H04L 5/0092 20130101; H04W 72/0406 20130101; Y02D 70/146 20180101;
H04W 72/048 20130101; H04W 72/121 20130101; H04W 84/18 20130101;
H04B 7/0452 20130101; H04L 1/1867 20130101; Y02D 70/1242 20180101;
Y02D 70/21 20180101; H04B 1/12 20130101; H04B 1/3827 20130101; H04W
40/16 20130101; H04B 17/26 20150115; H04L 5/0007 20130101; H04L
25/03305 20130101; H04W 52/40 20130101; Y02D 70/144 20180101; Y02D
70/24 20180101; H04B 7/15557 20130101; H04W 52/0261 20130101; H04L
5/0053 20130101; H04J 11/0053 20130101; H04L 5/0057 20130101; H04W
72/0486 20130101; H04W 72/042 20130101; Y02D 70/142 20180101; H04J
11/005 20130101; H04L 1/0003 20130101; H04W 72/12 20130101; Y02D
70/1264 20180101; H04W 76/27 20180201; H04W 76/28 20180201; H04B
7/0617 20130101; H04B 17/345 20150115; H04L 1/0054 20130101; H04L
27/0008 20130101; H04W 84/042 20130101; Y02D 70/1262 20180101; H04L
5/0055 20130101; H04W 72/08 20130101; H04W 72/082 20130101; H04W
24/10 20130101; H04L 25/0206 20130101; H04W 36/10 20130101; H04W
72/1247 20130101; H04B 17/24 20150115; H04L 5/0048 20130101; H04L
5/0058 20130101; H04W 76/14 20180201 |
Class at
Publication: |
370/329 |
International
Class: |
H04W 72/12 20060101
H04W072/12; H04L 5/00 20060101 H04L005/00 |
Claims
1. An evolved node B (eNB) operable to provide physical broadcast
channel (PBCH) transmissions and physical downlink shared channel
(PDSCH) transmissions in a New Carrier Type (NCT), the eNB having
computer circuitry configured to: determine that the PDSCH is
scheduled to transmit information in at least one physical resource
block (PRB) that is used to transmit information in the PBCH;
determine a reference signal type for communicating the information
in the PDSCH and the PBCH; and identify a reference signal location
in the NCT for PBCH demodulation so that the PDSCH is not scheduled
to transmit information in the same reference signal location as
the PBCH, wherein the information in the PDSCH and the PBCH are
communicated according to the reference signal type.
2. The computer circuitry of claim 1, further configured to
communicate information in the PDSCH, at the eNB, by using user
equipment (UE) specific reference signal (UERS) based open loop
transmission mode (TM) for accommodating an UERS based PBCH
transmission.
3. The computer circuitry of claim 1, further configured to utilize
demodulation reference signal (DMRS) for communicating information
in the PBCH in the NCT.
4. The computer circuitry of claim 1, further configured to reserve
at least one DMRS port for communicating information in the PBCH in
the NCT, such that the reserved DMRS ports for communicating
information in the PBCH does not correspond to DMRS ports for
communicating information in the PDSCH.
5. The computer circuitry of claim 1, further configured to precode
at least one resource block (RB) or at least one resource element
(RE) included in the physical resource block (PRB) in response to
determining that random beamforming is used to communicate
information in the PBCH.
6. The computer circuitry of claim 1, further configured to:
determine that a closed loop transmission mode (TM) is being used
to communicate information in the PDSCH; and identify, at the eNB,
a DMRS port to communicate information in the PDSCH different than
the DMRS port used to communicate information in the PBCH.
7. The computer circuitry of claim 1, further configured to
identify at least one physical resource block (PRB) pattern
allocated in a common search space (CSS) resource using a cyclic
redundancy check (CRC) scrambling code.
8. The computer circuitry of claim 1, further configured to
identify common search space (CSS) resources using one or more
information bits to indicate at least one physical resource block
(PRB) pattern used for the CSS resources.
9. The computer circuitry of claim 8, wherein the one or more
information bits are information bits used to indicate a Physical
Hybrid-ARQ Indicator Channel (PHICH) configuration in the PBCH.
10. The computer circuitry of claim 8, wherein the one or more
information bits are one or more dummy bits in the PBCH.
11. A method for allocating at least one physical resource block
(PRB) for an Enhanced Physical Hybrid-ARQ Indicator Channel
(EPHICH) transmission for a New Carrier Type (NCT), the method
comprising: determining a number of bits associated with channel
coding for an acknowledgement (ACK) or negative acknowledgement
(NACK) in the EPHICH transmission; generating a plurality of
modulation symbols for each ACK or NACK in the EPHICH transmission
based in part on the number of bits associated with the ACK or
NACK; and mapping the plurality of modulation symbols as EPHICH
quadrants in one or more resource element blocks (REGs), wherein
the EPHICH quadrants are mapped to a plurality of physical resource
blocks (PRBs) allocated for EPHICH to increase frequency diversity
gain.
12. The method of claim 11, further comprising mapping the EPHICH
quadrants to the REGs across a frequency domain and mapping the
EPHICH quadrants to the REGs across a time domain.
13. The method of claim 11, further comprising interleaving an REG
index and sequentially mapping the EPHICH quadrants to an
interleaved REG.
14. The method of claim 11, further comprising allocating the
plurality of PRBs for EPHICH transmission by radio resource control
(RRC) signaling for the NCT.
15. The method of claim 11, further comprising: determining that
the plurality of PRBs allocated for the EPHICH overlap with at
least one PRB allocated for the physical downlink shared channel
(PDSCH); and applying rate mapping to the plurality of PRBs
allocated for the EPHICH while mapping resource elements (REs)
associated with the PDSCH.
16. The method of claim 11, further comprising: identifying an
orphan resource element (RE) in the resource element group (REG);
and excluding the REG with the orphan RE or an Orthogonal Frequency
Division Multiplexing (OFDM) symbol associated with the REG from
the EPHICH transmission.
17. A node operable to assign a plurality of physical resource
block (PRB) for an Enhanced Physical Hybrid-ARQ Indicator Channel
(EPHICH) transmission for a New Carrier Type (NCT), the node having
computer circuitry configured to: generate a plurality of EPHICH
modulation symbols for each acknowledgement (ACK) or negative
acknowledgement (NACK) in a EPHICH transmission based in part on a
number of bits associated with the ACK or NACK; index a plurality
of resource elements (REs) in one subframe available for the EPHICH
transmission in a frequency or time first order and interleave the
REs that are indexed with an interleaver; and allocate EPHICH
resources by mapping the plurality of EPHICH modulation symbols in
the one subframe to the interleaved indexed REs, wherein the EPHICH
modulation symbols are mapped as REs in the plurality of PRBs,
wherein a plurality of enhanced control channel elements (ECCEs)
associated with the REs are assigned for the EPHICH
transmission.
18. The computer circuitry of claim 17, wherein the ECCEs are
associated with a distributed enhanced Physical Downlink Control
Channel (EPDCCH) set.
19. The computer circuitry of claim 17, further configured to
multiplex one or more user equipments (UEs) associated with the
EPHICH in a frequency domain or a time domain.
20. The computer circuitry of claim 17, further configured to
allocate the EPHICH resources by multiplexing the EPHICH with the
EPDCCH in a common search space (CSS) or a UE-specific search space
(USS).
21. The computer circuitry of claim 17, further configured to
perform frequency division multiplexing (FDM) or time division
multiplexing (TDM) with the EPHICHs that are associated with at
least one user equipment (UE).
22. The computer circuitry of claim 17, further configured to map
the EPHICH used by at least one user equipment (UE) to a plurality
of PRBs to increase frequency diversity gain.
23. The computer circuitry of claim 17, further configured to
multiplex at least one user equipment (UE) associated with the
EPHICHs using code division multiplexing (CDM).
24. The computer circuitry of claim 17, further configured to
assign enhanced resource element groups (EREGs) in a distributed
enhanced Physical Downlink Control Channel (EPDCCH) set for the
EPHICH.
25. The computer circuitry of claim 17, further configured to
puncture the ECCEs equally with the EPHICH for balancing the number
of available REs in each ECCE for the EPDCCH transmission.
26. The computer circuitry of claim 17, wherein the node is
selected from a group consisting of a base station (BS), a Node B
(NB), an evolved Node B (eNB), a baseband unit (BBU), a remote
radio head (RRH), a remote radio equipment (RRE), or a remote radio
unit (RRU).
Description
RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional
Patent Application No. 61/732,851, filed Dec. 3, 2012 with a docket
number of P51116Z, the entire specification of which is hereby
incorporated by reference in its entirety for all purposes.
BACKGROUND
[0002] Wireless mobile communication technology uses various
standards and protocols to transmit data between a node (e.g. a
transmission station or a transceiver node) and a wireless device
(e.g. a mobile device). Some wireless devices communicate using
orthogonal frequency-division multiple access (OFDMA) in a downlink
(DL) transmission and single carrier frequency division multiple
access (SC-FDMA) in an uplink (UL) transmission. Standards and
protocols that use orthogonal frequency-division multiplexing
(OFDM) for signal transmission include the third generation
partnership project (3GPP) long term evolution (LTE), the Institute
of Electrical and Electronics Engineers (IEEE) 802.16 standard
(e.g., 802.16e, 802.16m), which is commonly known to industry
groups as WiMAX (Worldwide interoperability for Microwave Access),
and the IEEE 802.11 standard, which is commonly known to industry
groups as Wi-Fi.
[0003] In 3GPP radio access network (RAN) LTE systems, the node can
be a combination of Evolved Universal Terrestrial Radio Access
Network (E-UTRAN) Node Bs (also commonly denoted as evolved Node
Bs, enhanced Node Bs, eNodeBs, or eNBs) and Radio Network
Controllers (RNCs), which communicates with the wireless device,
known as a user equipment (UE). The downlink (DL) transmission can
be a communication from the node (e.g., eNodeB) to the wireless
device (e.g., UE), and the uplink (UL) transmission can be a
communication from the wireless device to the node.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Features and advantages of the invention will be apparent
from the detailed description which follows, taken in conjunction
with the accompanying drawings, which together illustrate, by way
of example, features of the invention; and, wherein:
[0005] FIG. 1 illustrates a block diagram of an orthogonal
frequency division multiple access (OFDMA) frame structure in
accordance with an example;
[0006] FIG. 2 illustrates the generation of an enhanced physical
hybrid automatic repeat request (ARQ) indicator channel (EPHICH)
and EPHICH quadrant to resource element group (REG) mapping in
accordance with an example
[0007] FIG. 3 illustrates the generation of an enhanced physical
hybrid automatic repeat request (ARQ) indicator channel (EPHICH)
for frequency division multiplexed (FDMed) or time division
multiplexed (TDMed) mapping in accordance with an example
[0008] FIGS. 4A and 4B illustrate an enhanced physical hybrid
automatic repeat request (ARQ) indicator channel (EPHICH) that is
frequency division multiplexed (FDMed) or time division multiplexed
(TDMed) being multiplexed with an enhanced physical downlink
control channel (EPDCCH) in accordance with an example;
[0009] FIG. 5 illustrates an enhanced physical hybrid automatic
repeat request (ARQ) indicator channel (EPHICH) multiplexed with an
enhanced physical downlink control channels (EPDCCH) with an
enhanced resource element group (EREG) granularity in accordance
with an example;
[0010] FIG. 6 depicts functionality of computer circuitry of an
evolved node B (eNB) operable to provide physical broadcast channel
(PBCH) transmissions and physical downlink shared channel (PDSCH)
transmissions in a New Carrier Type (NCT) in accordance with an
example;
[0011] FIG. 7 depicts a flow chart of a method for allocating at
least one physical resource block (PRB) for an Enhanced Physical
Hybrid-ARQ Indicator Channel (EPHICH) transmission for a New
Carrier Type (NCT) in accordance with an example;
[0012] FIG. 8 depicts functionality of computer circuitry of a node
operable to assign a plurality of physical resource block (PRB) for
an Enhanced Physical Hybrid-ARQ Indicator Channel (EPHICH)
transmission for a New Carrier Type (NCT) in accordance with an
example; and
[0013] FIG. 9 illustrates a block diagram of a mobile device (e.g.,
a user equipment) in accordance with an example.
[0014] Reference will now be made to the exemplary embodiments
illustrated, and specific language will be used herein to describe
the same. It will nevertheless be understood that no limitation of
the scope of the invention is thereby intended.
DETAILED DESCRIPTION
[0015] Before the present invention is disclosed and described, it
is to be understood that this invention is not limited to the
particular structures, process steps, or materials disclosed
herein, but is extended to equivalents thereof as would be
recognized by those ordinarily skilled in the relevant arts. It
should also be understood that terminology employed herein is used
for the purpose of describing particular embodiments only and is
not intended to be limiting.
DEFINITIONS
[0016] As used herein, the term "substantially" refers to the
complete or nearly complete extent or degree of an action,
characteristic, property, state, structure, item, or result. For
example, an object that is "substantially" enclosed would mean that
the object is either completely enclosed or nearly completely
enclosed. The exact allowable degree of deviation from absolute
completeness may in some cases depend on the specific context.
However, generally speaking the nearness of completion will be so
as to have the same overall result as if absolute and total
completion were obtained. The use of "substantially" is equally
applicable when used in a negative connotation to refer to the
complete or near complete lack of an action, characteristic,
property, state, structure, item, or result.
Example Embodiments
[0017] An initial overview of technology embodiments is provided
below and then specific technology embodiments are described in
further detail later. This initial summary is intended to aid
readers in understanding the technology more quickly but is not
intended to identify key features or essential features of the
technology nor is it intended to limit the scope of the claimed
subject matter. The following definitions are provided for clarity
of the overview and embodiments described below.
[0018] FIG. 1 illustrates a downlink radio frame structure type 2.
In the example, a radio frame 100 of a signal used to transmit the
data can be configured to have a duration, T.sub.f, of 10
milliseconds (ms). Each radio frame can be segmented or divided
into ten subframes 110i that are each 1 ms long. Each subframe can
be further subdivided into two slots 120a and 120b, each with a
duration. T.sub.slot, of 0.5 ms. The first slot (#0) 120a can
include a legacy physical downlink control channel (PDCCH) 160
and/or a physical downlink shared channel (PDSCH) 166, and the
second slot (#1) 120b can include data transmitted using the
PDSCH.
[0019] Each slot for a component carrier (CC) used by the node and
the wireless device can include multiple resource blocks (RBs)
130a, 130b, 130i, 130m, and 130n based on the CC frequency
bandwidth. The CC can have a carrier frequency having a bandwidth
and center frequency. Each subframe of the CC can include downlink
control information (DCI) found in the legacy PDCCH. The legacy
PDCCH in the control region can include one to three columns of the
first OFDM symbols in each subframe or RB, when a legacy PDCCH is
used. The remaining 11 to 13 OFDM symbols (or 14 OFDM symbols, when
legacy PDCCH is not used) in the subframe may be allocated to the
PDSCH for data (for short or normal cyclic prefix).
[0020] The control region can include physical control format
indicator channel (PCFICH), physical hybrid automatic repeat
request (hybrid-ARQ) indicator channel (PHICH), and the PDCCH. The
control region has a flexible control design to avoid unnecessary
overhead. The number of OFDM symbols in the control region used for
the PDCCH can be determined by the control channel format indicator
(CFI) transmitted in the physical control format indicator channel
(PCFICH). The PCFICH can be located in the first OFDM symbol of
each subframe. The PCFICH and PHICH can have priority over the
PDCCH, so the PCFICH and PHICH are scheduled prior to the
PDCCH.
[0021] Each RB (physical RB or PRB) 130i can include 12-15 kHz
subcarriers 136 (on the frequency axis) and 6 or 7 orthogonal
frequency-division multiplexing (OFDM) symbols 132 (on the time
axis) per slot. The RB can use seven OFDM symbols if a short or
normal cyclic prefix is employed. The RB can use six OFDM symbols
if an extended cyclic prefix is used. The resource block can be
mapped to 84 resource elements (REs) 140i using short or normal
cyclic prefixing, or the resource block can be mapped to 72 REs
(not shown) using extended cyclic prefixing. The RE can be a unit
of one OFDM symbol 142 by one subcarrier (i.e., 15 kHz) 146.
[0022] Each RE can transmit two bits 150a and 150b of information
in the case of quadrature phase-shift keying (QPSK) modulation.
Other types of modulation may be used, such as 16 quadrature
amplitude modulation (QAM) or 64 QAM to transmit a greater number
of bits in each RE, or bi-phase shift keying (BPSK) modulation to
transmit a lesser number of bits (a single bit) in each RE. The RB
can be configured for a downlink transmission from the eNodeB to
the UE, or the RB can be configured for an uplink transmission from
the UE to the eNodeB.
[0023] Downlink physical channels for transmitting information
transferred to a downlink transport channel to a radio interval
between the UE and the network include a Physical Broadcast Channel
(PBCH) for transmitting BCH information, a Physical Downlink Shared
Channel (PDSCH) for transmitting downlink shared channel (SCH)
infomnnation, and a Physical Downlink Control Channel (PDCCH) (also
called a DL L1/L2 control channel) for transmitting control
information, such as DL/UL Scheduling Grant information, received
from first and second layers (L1 and L2).
[0024] In general, the PBCH may broadcast a limited number of
parameters essential for initial access of the cell such as
downlink system bandwidth, the Physical Hybrid ARQ Indicator
Channel structure, and the most significant eight-bits of the
System Frame Number. These parameters may be carried in a Master
Information Block which is 14 bits long. The PBCH may be designed
to be detectable without prior knowledge of system bandwidth and to
be accessible at the cell edge. The MIB can be coded at a very low
coding rate and mapped to the 72 center sub-carriers (6 RBs) of the
OFDM structure. The PBCH transmission is spread over four 10 ms
frames (over subframe #0) to span a 40 ms period.
[0025] In general, the PDSCH is the main downlink data-bearing
channel in LTE. The PDSCH can be used to transmit all user data, as
well as for broadcast system information that is not communicated
on the PBCH. In addition, the user data can be mapped to spatial
layers according to the type of multi-antenna technique (e.g.
closed loop spatial multiplexing, open-loop, spatial multiplexing,
transmit diversity, etc.) and then mapped to a modulation symbol
which includes Quadrature Phase Shift Keying (QPSK), 16 Quadrature
Amplitude Modulation (QAM) and 64 QAM.
[0026] In one example, the PCFICH can communicate the Control Frame
Indicator (CFI), which includes the number of OFDM symbols used for
control channel transmission in each subframe (typically 1, 2, or
3). The 32-bit long CFI is mapped to 16 Resource Elements in the
first OFDM symbol of each downlink frame using QPSK modulation.
[0027] In one configuration, the PHICH can communicate the HARQ
ACK/NAK, which indicates to the UE whether the eNodeB correctly
received uplink user data carried on the PUSCH. In addition. BPSK
modulation can be used with a repetition factor of 3 to increase
robustness.
[0028] In one example, the PDCCH can communicate the resource
assignment for UEs which are contained in a Downulink Control
Information (DCI) message. Multiple wireless devices can be
scheduled in one subframe of a radio frame. Therefore, multiple DCI
messages can be sent using multiple PDCCHs. QPSK modulation can be
used for the PDCCH. Four QPSK symbols can be mapped to each REG.
The DCI information in a PDCCH can be transmitted using one or more
control channel elements (CCE). A CCE can be comprised of a group
of resource element groups (REGs). A legacy CCE can include up to
nine REGs. Each legacy REG can be comprised of four resource
elements (REs). Each resource element can include two bits of
information when quadrature modulation is used. Therefore, a legacy
CCE can include up to 72 bits of information. When more than 72
bits of information are needed to convey the DCI message, multiple
CCEs can be employed. The use of multiple CCEs can be referred to
as an aggregation level. In one example, the aggregation levels can
be defined as 1, 2, 4 or 8 consecutive CCEs allocated to one
PDCCH.
[0029] The legacy PDCCH can create limitations to advances made in
other areas of wireless communication. For example, mapping of CCEs
to subframes in OFDM symbols can typically be spread over the
control region to provide frequency diversity. However, no beam
forming diversity may be possible with the current mapping
procedures.
[0030] Moreover, the capacity of the legacy PDCCH may not be
sufficient for advanced control signaling. For instance, networks
may be configured as heterogeneous networks (HetNets) that can
include a number of different kinds of nodes in a single macro cell
serving area. More wireless devices can be served simultaneously by
macro and pico cells in the HetNet. The PDCCH can be designed to
demodulate based on cell-specific reference signals (CRS), which
can make fully exploring cell splitting gain difficult. The legacy
PDCCH may not be adequate to convey the information needed to allow
a wireless device to take advantage of the multiple transmission
nodes in the HetNet to increase bandwidth and decrease battery
usage at the wireless device.
[0031] In addition, an increased capacity in the PDCCH can be
useful in the use of multi-user multiple-input multiple-output
(MU-MIMIO), machine to machine communication (M2M), PDSCH
transmission in a multicast\broadcast single-frequency network, and
cross carrier scheduling. The use of UE specific reference signals
(UERS) in PDCCH demodulation at the wireless device can allow the
use of multiple nodes in the HetNet. Rather than relying on a
single common reference symbol (e.g., CRS) for an entire cell, each
reference symbol can be UE specific (e.g., UERS).
[0032] To overcome the limitations of the legacy PDCCH an enhanced
PDCCH (EPDCCH) can use the REs in an entire PRB or PRB pair (where
a PRB pair is two contiguous PRBs using the same subcarrier's
subframe), instead of just the first one to three columns of OFDM
symbols in a first slot PRB in a subframe as in the legacy PDCCH.
Accordingly, the EPDCCH can be configured with increased capacity
to allow advances in the design of cellular networks and to
minimize currently known challenges and limitations.
[0033] Unlike the legacy PDCCH the EPDCCH can be mapped to the same
REs or region in a PRB as the PDSCH, but in different PRBs. In an
example, the PDSCH and the EPDCCH may not be multiplexed within a
same PRB (or a same PRB pair). Thus if one PRB (or one PRB pair)
contains an EPDCCH, the unused REs in the PRB (or PRB pair) may be
blanked, since the REs may not be used for the PDSCH.
[0034] As the evolution of LTE-advanced (LTE-A) keeps increasing
support for multi-user MIMO (MU-MIMO), more UEs can be scheduled
per sub-frame for the MU-MIMO operation, which can increase the
physical down link control channel (PDCCH) resource demand for
downlink scheduling. The legacy PDCCH design (e.g., LTE Rel-8/9/10)
with the maximum PDCCH size of 3 OFDM symbols may not meet an
increased demand, which can consequently limit the gain from
MU-MIMO. The PDCCH extension design, called enhanced PDCCH (EPDCCH
or E-PDCCH), can be located in the PDSCH region for an advanced
PDCCH (e.g. LTE Release 11 and subsequent releases). The EPDCCH can
use a PRB-based (instead of CCE-based PDCCH design) multiplexing
scheme to increase the PDCCH capacity and improve enhanced
inter-cell interference coordination (eICIC) support in HetNet
scenarios. The limitation of the legacy PDCCH design to effectively
perform inter-cell interference coordination (ICIC) on the legacy
PDCCH can be due to PDCCH interleaving, where the control channel
elements (CCEs) used for the transmission of DCI formats in PDCCH
are distributed over the entire bandwidth (BW). Conversely, the
enhanced PDCCH (EPDCCH) in PDSCH region can be designed using a
PRB-based scheme to achieve the benefit to support frequency-domain
ICIC.
[0035] In some carrier types supporting EPDCCH (e.g. carrier types
in LTE-Release 11), the location and size of the EPDCCH regions can
be indicated to the user equipment/mobile station (UE/MS) through
radio resource control (RRC) signaling, which can use the PDCCH and
UE's reading of PDCCH to obtain such RRC configuration from a
primary cell (PCell). However, new carrier types (NCT), which may
be used by next generation UEs/MSs (e.g., UEs/MSs using LTE-Release
12 and subsequent releases), may use stand-alone carriers without a
legacy PDDCH.
[0036] In LTE Release 12 or Release 11, the NCT is a non-backward
compatible carrier for boosting throughput by reducing the emphasis
on common reference symbols (CRS). The NCT can reduce and/or
eliminate legacy control signaling and/or CRS. In addition, the
density of the CRS may be reduced in both the frequency domain and
the time domain. The new carrier type can enhance spectral
efficiency, improved support for heterogeneous networks (HetNets),
and improve energy efficiency. Either a synchronized or
unsynchronized carrier type can support the new carrier type. The
new carrier type can be non-stand alone or stand alone
[0037] Legacy control channels, such as the physical broadcast
channel (PBCH), the physical hybrid automatic repeat request (ARQ)
indicator channel (PHICH), the physical control format indicator
channel (PCFICH), and the physical downlink control channel (PDCCH)
that rely on CRS for demodulation may be optimized for NCT. In LTE
Release 11, EPDCCH which was demodulated based on demodulation
reference signals (DMRS), was introduced as an enhanced version of
legacy PDCCH for UE search space (USS). Similarly, the PHICH, PBCH,
PCFICH, and the common search space (CSS) in the PDCCH may be
optimized for NCT.
[0038] In one configuration, at least three alternatives may be
used to indicate the CSS resources for the NCT. In alternative one,
a cyclic redundancy check (CRC) scrambling code for the PBCH may be
used to indicate the CSS resources. In general, the CRC is used for
error detection in DCI messages. Since CRS is not used for
demodulation in the NCT, the CRC scrambling code used for the PBCH
is not needed to indicate a CRS antenna port. Thus, this signaling
may be reused to indicate CSS resources for the user equipment (UE)
to monitor for blind decoding. In general, the UE may perform blind
decoding when unaware of the detailed control channel structure,
including the number of control channels and the number of control
channel elements (CCEs) to which each control channel is mapped. In
one example, one or more PRB patterns may be hard coded into the
3GPP LTE Technical Specification (TS), and the CRC scrambling code
may be used to indicate one or more PRB patterns that are allocated
for the CSS resources.
[0039] In alternative two, a plurality of bits used to configure
the legacy PHICH may be used to indicate the CSS resources. In one
example, 3 bits used to configure the legacy PHICH may be reused
for the PBCH. If the exclusive PRBs are allocated for EPHICH
transmission, then the 3 bits used to indicate the configuration of
the PHICH may be reused for indication of the CSS resources.
[0040] In alternative three, dummy bits in the PBCH may be used to
indicate one or more PRB patterns that are allocated for the CSS
resources. In one example, there may be 10 dummy bits out of 24
information bits in the PBCH. Thus, any one, or a combination of,
these 10 dummy bits may be used to indicate one or more PRB
patterns that are allocated for the CSS resources.
[0041] In one example, any combination of alternative one,
alternative two, and alternative three may be combined for
indicating the CSS resources in the NCT. For example, three bits
may be carried by alternative two and two additional bits may be
carried by alternative one. Thus, the five combined bits may be
used to indicate the CSS resources in the NCT.
[0042] In one configuration, demodulation reference signals (DRMS)
may be utilized for PBCH transmission in the NCT, as CRS may not be
used for PBCH demodulation in the NCT. In general, DMRS can be used
to enable coherent signal demodulation at the eNodeB. If random
beamforming is used, a precoder may cycle per RB or per several RE
within a PRB, including a single RE.
[0043] The changes in the NCT have created some potential problems.
In one example, the PDSCH may be scheduled to transmit information
in PRBs in the same PRBs that the PBCH is to transmit information.
However, the same resources cannot be concurrently used to transmit
information for both the PDSCH and the PBCH. At least three
solutions may be presented to avoid the same PRBs being scheduled
for use at the same time for both the PDSCH and the PBCH.
[0044] In solution one, the DMRS ports used for PBCH transmission
may be hard coded in the 3GPP LTE TS. As an example, DMRS ports 7
and 8 may be reserved for PBCH demodulation. As a result, the DMRS
ports reserved for PBCH demodulation may not be scheduled for use
by the PDSCH, and therefore, the PDSCH transmission may not
conflict with the PBCH transmission.
[0045] In solution two, the eNB may transmit information in the
PDSCH using a UERS based open loop transmission mode (TM). The UERS
based open loop TM may accommodate the UERS based PBCH
transmission. Thus, the PDSCH transmission may not conflict with
the PBCH transmission.
[0046] In solution three, when an open loop TM is used for the
PDSCH transmission, the eNB may use a different DMRS port for the
PBCH transmission as compared to the PBCH transmission. For
example, the PBCH transmission may occur with DMRS ports 7 and 8.
The UE may assume an offset is added on top of the DMRS port
indicated in the DCI for the PDSCH demodulation. The value of the
offset may be the number of DMRS ports used in the PBCH
transmission. Thus, if the DMRS port indicated in the DCI is 7 and
DMRS ports 7 and 8 are reserved for PBCH demodulation, then the UE
may use DMRS port 9 for PDSCH demodulation because 7+2 (the offset
value)=9.
[0047] FIG. 2 is an example illustrating the generation of an
EPHICH and EPHICH quadrant to resource element group (REG) mapping.
The EPHICH symbol generation procedure may reuse the legacy PHICH
physical layer structure, i.e., constructing the REG and then
mapping the EPHICH quadrant to the REG.
[0048] In one configuration, exclusive PRBs may be assigned for
EPHICH transmissions. In addition, one or more PRBs may be
allocated for the EPHICH transmissions using radio resource control
(RRC) signaling for the NCT. If the PRBs allocated for the PDSCH
transmission overlap with the PRBs allocated for the EPHICH
transmission, then rate matching may be applied around the EPHICH
PRBs in the PDSCH RE mapping process. In general, the rate matching
(RM) process can adapt the code rate of the LTE data transmissions
such that the number of information and parity bits to be
transmitted matches the resource allocation.
[0049] As shown in FIG. 2, channel coding for ACK is 111 (3 bits)
and for NAK is 000 (3 bits). In other words. ACK is 1 (1 bit) with
a Nx repetition of N=3 and NAK is 0 (1 bit) with a Nx repetition of
N=3. The EPHICH may use binary phase shift keying (BPSK) modulation
so that 3 modulation symbols are generated for each ACK or NAK. In
general, BPSK is a modulation scheme that conveys one bit per
symbol, whereby the values of the bit are represented by opposite
phases of the carrier. The modulation symbols may be multiplied by
an orthogonal cover code with a spreading factor of four (i.e.,
OCC4) for the normal cyclic prefix, resulting in a total of 12
modulation symbols. Since each REG contains 4 REs and each RE can
carry one modulation symbol, 3 REs are needed for a single EPHICH.
As shown in FIG. 2. REG0, REG1 and REG2 may be included in EPHICH
group 1. In addition. REG3, REG4 and REG5 may be included in EPHICH
group 2.
[0050] In one configuration, EPHICH quadrant to REG mapping may
include distributing the PHICH quadrant to as many PRBs (that are
allocated for EPHICH) as possible for reaping financial diversity
gain. As shown in FIG. 2, the EPHICH quadrant is mapped to the REG
across the frequency domain and then across the time domain. In an
alternative configuration, an REG index may be interleaved and then
the EPHICH quadrant may be sequentially mapped to the interleaved
REG.
[0051] In one example, the EPHICH demodulation may be based on the
DMRS. Thus, the EPHICH may reuse the same DMRS port as the
distributed EPDCCH. In addition, the DMRS sequence scrambling
initialization may reuse the conclusion of the EPDCCH, i.e., the
virtual cell identifier (ID) may be configured from higher layer
signaling. In one example, a per RE/REG cycled random precoding may
be applied to the EPHICH demodulation. In addition, DMRS based
transmit diversity may be used, but orphan REs may be accounted.
Thus, if there is an orphan RE in one REG, the entire REG or the
OFDM symbol associated with the REG may not be used for the EPHICH
transmission.
[0052] In order to indicate the EPHICH resource (e.g. group ID,
sequence ID), the implicit PHICH group and sequence indication may
be reused from LTE Release 11 and earlier releases. Furthermore,
since the EPHICH and the EPDCCH are not multiplexed in the same
PRB, at least 3 bits in the PBCH for the indication of the PHICH
configuration may be saved. Thus, these 3 bits may be reused for
indicating the CSS resources in the NCT.
[0053] FIG. 3 illustrates an example of the generation of an
enhanced physical hybrid automatic repeat request (ARQ) indicator
channel (EPHICH) for frequency division multiplexed (FDMed) or time
division multiplexed (TDMed) mapping. The ACK/NAK bit may be
repeated N times and then BPSK modulated. A phase rotation process
may be added to support additional UEs in a single EPHICH group. In
general, N may dominate the spectrum efficiency of the EPHICH. In
one example. N=3 results in SE=2 bits/3 REs. M may be the number of
UEs supported in the single EPHICH group. M may be the same as the
legacy PHICH, i.e., M=8 to facilitate reusing the PHICH
group/sequence indication as used in the legacy PHICH.
[0054] In the EPICH to RE mapping process, the REs available for
the EPHICH may be indexed in a frequency domain or a time domain to
generate i(0), i(1), . . . i(N_RE), wherein N_RE is the number of
REs available for the EPHICH transmission in one subframe. The
indices may be interleaved with an interleaver to generate j(0),
j(1), . . . j(N.sub.RE). The EPHICH symbols may be sequentially
mapped in one subframe to j(0), j(1), . . . j(N.sub.RE). In one
example, the interleaver may reuse the sub-block interleaver in
legacy turbo coding or another interleaver.
[0055] As shown in FIG. 3, the REs associated with A/N bit 1 &
2 may be mapped to the plurality of PRBs, the REs associated
withA/N bit 3 & 4 may be mapped to the plurality of PRBs, and
the REs associated with A/N bit M-1 & M may be mapped to the
plurality of PRBs. In EPHICH to RE mapping, the EPHICH for one UE
may be distributed to as many different PRBs as possible for
procuring frequency diversity gain.
[0056] FIGS. 4A and 4B illustrate an example of the EPHICH
multiplexed with the EPDCCH. In one example. ECCEs (in a
distributed EPDCCH set) may be assigned for the EPHICH. In
addition, EPHICHs associated with different UEs may be frequency
division multiplexed (FDMed) or time division multiplexed (TDMied).
In general, FDM relates to multiplexing different data signals for
transmission on a single communications channel, whereby each
signal is assigned a non-overlapping frequency range within the
main channel. In addition, TDM relates to multiplexing different
data signals, whereby the channel is divided into multiple time
slots and the different signals are mapped to different time
slots.
[0057] As shown in FIGS. 4A and 4B, EPHICHs associated with
different UEs may be FDMed or TDMed and multiplexed with the
EPDCCH. Two A/N bits may be transmitted and each of the two A/N
bits may be repeated four times (i.e., N=4). In this example, the
ECCE which is constructed by EREG 0, 4, 8, and 12 is allocated for
the EPHICH transmission. In particular, EREG 0, 4, 8 and 12 may be
associated with EPHICH 1 or EPHICH 2. FIGS. 4A and 4B illustrate
two types of checkered patterns to indicate the resources for
EPHICH 1 and EPHICH 2. A third type of checkered pattern may
indicate all resources of one ECCE, which may include the EREGs 0,
4, 8 or 12. The remaining EREGs shown in FIGS. 4A and 4B (i.e.
represented by the solid boxes without a checkered pattern) may be
associated with the EPDCCH.
[0058] In one example, the EECEs allocated for EPHICH transmissions
are punctured by the EPHICH. In coding theory, puncturing is the
process of removing some of the parity bits after encoding with an
error-correction code. Puncturing can have the same effect as
encoding with an error-correction code with a higher rate (e.g.,
modulation and coding scheme (MCS)), or less redundancy. With
puncturing a same decoder can be used regardless of how many bits
have been punctured, thus puncturing can considerably increase the
flexibility of a system without significantly increasing the
system's complexity.
[0059] For EPHICH resource allocation, the EPHICH may be
multiplexed with the EPDCCH in common search space (CSS) or UE
search space (USS). The 3 bits that are used in the PBCH to
indicate the legacy PHICH configuration may be reused to indicate
the EPHICH resources. In addition, 8 ECCE patterns may be
predefined and 3 bits may be used to indicate which ECCE pattern is
applied in the serving cell. For example, a single bit may indicate
that either the CSS or the USS is multiplexed with the EPHICH, and
the remaining two bits may be used to select the ECCE pattern.
[0060] In one example, the EPHICH demodulation may be based on the
DMRS. Thus, the EPHICH may reuse the same DMRS port as the
distributed EPDCCH. In addition, the DMRS sequence scrambling
initialization may reuse the conclusion of the EPDCCH. i.e., the
virtual cell identifier (ID) may be configured from higher layer
signaling. In one example, a per RE/REG cycled random precoding may
be applied to the EPHICH demodulation. The UE may search ECCEs that
are allocated to the EPHICH during EPDCCH blind detection.
Alternatively, the UE may not search ECCEs that are allocated to
the EPHICH during EPDCCH blind detection. In order to indicate the
EPHICH resource (e.g., group ID, sequence ID), the implicit PHICH
group and sequence indication may be reused from LTE Release 11 and
earlier releases.
[0061] In an alternative configuration, the EPHICH may be
multiplexed with the EPDCCH, wherein the EECEs (in the distributed
EPDCCH set) may be assigned for the EPHICH and EPHICHs of different
UEs may be code division multiplexed (CDMed). In general, CDM
relates to multiplexing different data signals by means of
different codes, rather than different frequencies or timeslots.
The codes used for different signals may be orthogonal to each
other, or may be pseudo-random and have a wider bandwidth than the
data signals. In one example, the EPHICH symbol generation
procedure may reuse the legacy PHICH processor for generating
symbols. In addition, other procedures may reuse the procedures as
previously described.
[0062] FIG. 5 illustrates an example of an EPHICH multiplexed with
an EPDCCH with an enhanced resource element group (EREG)
granularity. The EREGs (in the distributed EPDCCH set) may be
assigned for the EPHICH. While in one configuration, the EPHICH may
puncture the ECCEs allocated for the EPHICH transmission, in an
alternative configuration, all of the ECCEs may be equally
punctured with the EPHICH to balance the number of available REs in
each ECCE for the EPDCCH transmission. The EPHICH symbol generation
procedure may reuse the TDM/FDM procedure or the CDM procedure as
previously described. In addition, the resources allocated for the
EPHICH transmission may be measured in terms of EREGs. As shown in
FIG. 5, each ECCE may be equally punctured. The unfilled EREG may
be allocated for the EPHICH transmission, whereas the filled EREG
may be allocated for EPDCCH transmission. Subsequently, each ECCE
may be equally punctured by the EPHICH. In addition, the PRBs may
be assigned to the EPDCCH and can be distributed across an entire
bandwidth.
[0063] Another example provides functionality 600 of computer
circuitry of an evolved node B (eNB) operable to provide physical
broadcast channel (PBCH) transmissions and physical downlink shared
channel (PDSCH) transmissions in a New Carrier Type (NCT), as shown
in the flow chart in FIG. 6. The functionality may be implemented
as a method or the functionality may be executed as instructions on
a machine, where the instructions are included on at least one
computer readable medium or one non-transitory machine readable
storage medium. The computer circuitry can be configured to
determine that the PDSCH is scheduled to transmit information in at
least one physical resource block (PRB) that is used to transmit
information in the PBCH, as in block 610. The computer circuitry
can be configured to determine a reference signal type for
communicating the information in the PDSCH and the PBCH, as in
block 620. The computer circuitry can be further configured to
identify a reference signal location in the NCT for PBCH
demodulation so that the PDSCH is not scheduled to transmit
information in the same reference signal location as the PBCH,
wherein the information in the PDSCH and the PBCH are communicated
according to the reference signal type, as in block 630.
[0064] In one example, the computer circuitry can be configured to
communicate information in the PDSCH, at the eNB, by using user
equipment (UE) specific reference signal (UERS) based open loop
transmission mode (TM) for accommodating an UERS based PBCH
transmission. In addition, the computer circuitry can be configured
to utilize demodulation reference signal (DMRS) for communicating
information in the PBCH in the NCT.
[0065] In one configuration, the computer circuitry can be
configured to reserve at least one DMRS port for communicating
information in the PBCH in the NCT, such that the reserved DMRS
ports for communicating information in the PBCH does not correspond
to DMRS ports for communicating information in the PDSCH. In one
example, the computer circuitry can be configured to precode at
least one resource block (RB) or at least one resource element (RE)
included in the physical resource block (PRB) in response to
determining that random beamforming is used to communicate
information in the PBCH.
[0066] In one configuration, the computer circuitry can be
configured to determine that a closed loop transmission mode (TM)
is being used to communicate information in the PDSCH; and
identify, at the eNB, a DMRS port to communicate information in the
PDSCH different than the DMRS port used to communicate information
in the PBCH. In addition, the computer circuitry can be configured
to identify at least one physical resource block (PRB) pattern
allocated in a common search space (CSS) resource using a cyclic
redundancy check (CRC) scrambling code.
[0067] Furthermore, the computer circuitry can be configured to
identify common search space (CSS) resources using one or more
information bits to indicate at least one physical resource block
(PRB) pattern used for the CSS resources. In one example, the one
or more information bits are information bits used to indicate a
Physical Hybrid-ARQ Indicator Channel (PHICH) configuration in the
PBCH. In an alternative example, the one or more information bits
are one or more dummy bits in the PBCH.
[0068] Another example provides a method 700 for allocating at
least one physical resource block (PRB) for an Enhanced Physical
Hybrid-ARQ Indicator Channel (EPHICH) transmission for a New
Carrier Type (NCT), as shown in the flow chart in FIG. 7. The
method may be executed as instructions on a machine, where the
instructions are included on at least one computer readable medium
or one non-transitory machine readable storage medium. The method
includes the operation of determining a number of bits associated
with channel coding for an acknowledgement (ACK) or negative
acknowledgement (NACK) in the EPHICH transmission, as in block 710.
The method includes generating a plurality of modulation symbols
for each ACK or NACK in the EPHICH transmission based in part on
the number of bits associated with the ACK or NACK, as in block
720. The method additionally includes mapping the plurality of
modulation symbols as EPHICH quadrants in one or more resource
element blocks (REGs), wherein the EPHICH quadrants are mapped to a
plurality of physical resource blocks (PRBs) allocated for EPHICH
to increase frequency diversity gain, as in block 730.
[0069] In one configuration, the method can include mapping the
EPHICH quadrants to the REGs across a frequency domain and mapping
the EPHICH quadrants to the REGs across a time domain. In addition,
the method can include interleaving an REG index and sequentially
mapping the EPHICH quadrants to an interleaved REG.
[0070] In one example, the method can include allocating the
plurality of PRBs for EPHICH transmission by radio resource control
(RRC) signaling for the NCT. In addition, the method can include
determining that the plurality of PRBs allocated for the EPHICH
overlap with at least one PRB allocated for the physical downlink
shared channel (PDSCH); and applying rate mapping to the plurality
of PRBs allocated for the EPHICH while mapping resource elements
(REs) associated with the PDSCH. Furthermore, the method can
include identifying an orphan resource element (RE) in the resource
element group (REG); and excluding the REG with the orphan RE or an
Orthogonal Frequency Division Multiplexing (OFDM) symbol associated
with the REG from the EPHICH transmission.
[0071] FIG. 8 provides functionality 800 of computer circuitry of a
node operable to assign a plurality of physical resource block
(PRB) for an Enhanced Physical Hybrid-ARQ Indicator Channel
(EPHICH) transmission for a New Carrier Type (NCT). The
functionality may be implemented as a method or the functionality
may be executed as instructions on a machine, where the
instructions are included on at least one computer readable medium
or one non-transitory machine readable storage medium. The computer
circuitry can be configured to generate a plurality of EPHICH
modulation symbols for each acknowledgement (ACK) or negative
acknowledgement (NACK) in an EPHICH transmission based in part on a
number of bits associated with the ACK or NACK, as in block 810.
The computer circuitry can be configured to index a plurality of
resource elements (REs) in one subframe available for the EPHICH
transmission in a frequency or time first order and interleave the
REs that are indexed with an interleaver, as in block 820. The
computer circuitry can be further configured to allocate EPHICH
resources by mapping the plurality of EPHICH modulation symbols in
the one subframe to the interleaved indexed REs, wherein the EPHICH
modulation symbols are mapped as REs in the plurality of PRBs,
wherein a plurality of enhanced control channel elements (ECCEs)
associated with the REs are assigned for the EPHICH transmission,
as in block 830.
[0072] In one example, the ECCEs can be associated with a
distributed enhanced Physical Downlink Control Channel (EPDCCH)
set. In addition, the computer circuitry can be further configured
to perform frequency division multiplexing (FDM) or time division
multiplexing (TDM) with the EPHICHs that are associated with at
least one user equipment (UE). Furthermore, the computer circuitry
can be configured to allocate the EPHICH resources by multiplexing
the EPHICH with the EPDCCH in a common search space (CSS) or a
UE-specific search space (USS).
[0073] In one configuration, the computer circuitry can be further
configured to multiplex at least one user equipment (UE) associated
with the EPHICHs in a frequency domain or a time domain. In
addition, the computer circuitry can be further configured to map
the EPHICH used by at least one user equipment (UE) to a plurality
of PRBs to increase frequency diversity gain. Furthermore, the
computer circuitry can be configured to multiplex at least one user
equipment (UE) associated with the EPHICHs using code division
multiplexing (CDM).
[0074] In one configuration, the computer circuitry can be further
configured to assign enhanced resource element groups (EREGs) in a
distributed enhanced Physical Downlink Control Channel (EPDCCH) set
for the EPHICH. In addition, the computer circuitry can be further
configured to puncture the ECCEs equally with the EPHICH for
balancing the number of available REs in each ECCE for the EPDCCH
transmission. In one example, the node is selected from a group
consisting of a base station (BS), a Node B (NB), an evolved Node B
(eNB), a baseband unit (BBU), a remote radio head (RRH), a remote
radio equipment (RRE), or a remote radio unit (RRU).
[0075] FIG. 9 provides an example illustration of the mobile
device, such as a user equipment (UE), a mobile station (MS), a
mobile wireless device, a mobile communication device, a tablet, a
handset, or other type of mobile wireless device. The mobile device
can include one or more antennas configured to communicate with a
node, macro node, low power node (LPN), or, transmission station,
such as a base station (BS), an evolved Node B (eNB), a base band
unit (BBU), a remote radio head (RRH), a remote radio equipment
(RRE), a relay station (RS), a radio equipment (RE), or other type
of wireless wide area network (WWAN) access point. The mobile
device can be configured to communicate using at least one wireless
communication standard including 3GPP LTE, WiMAX, High Speed Packet
Access (HSPA), Bluetooth, and Wi-Fi. The mobile device can
communicate using separate antennas for each wireless communication
standard or shared antennas for multiple wireless communication
standards. The mobile device can communicate in a wireless local
area network (WLAN), a wireless personal area network (WPAN),
and/or a WWAN.
[0076] FIG. 9 also provides an illustration of a microphone and one
or more speakers that can be used for audio input and output from
the mobile device. The display screen may be a liquid crystal
display (LCD) screen, or other type of display screen such as an
organic light emitting diode (OLED) display. The display screen can
be configured as a touch screen. The touch screen may use
capacitive, resistive, or another type of touch screen technology.
An application processor and a graphics processor can be coupled to
internal memory to provide processing and display capabilities. A
non-volatile memory port can also be used to provide data
input/output options to a user. The non-volatile memory port may
also be used to expand the memory capabilities of the mobile
device. A keyboard may be integrated with the mobile device or
wirelessly connected to the mobile device to provide additional
user input. A virtual keyboard may also be provided using the touch
screen.
[0077] Various techniques, or certain aspects or portions thereof,
may take the form of program code (i.e. instructions) embodied in
tangible media, such as floppy diskettes, CD-ROMs, hard drives,
non-transitory computer readable storage medium, or any other
machine-readable storage medium wherein, when the program code is
loaded into and executed by a machine, such as a computer, the
machine becomes an apparatus for practicing the various techniques.
In the case of program code execution on programmable computers,
the computing device may include a processor, a storage medium
readable by the processor (including volatile and non-volatile
memory and/or storage elements), at least one input device, and at
least one output device. The volatile and non-volatile memory
and/or storage elements may be a RAM, EPROM, flash drive, optical
drive, magnetic hard drive, or other medium for storing electronic
data. The base station and mobile device may also include a
transceiver module, a counter module, a processing module, and/or a
clock module or timer module. One or more programs that may
implement or utilize the various techniques described herein may
use an application programming interface (API), reusable controls,
and the like. Such programs may be implemented in a high level
procedural or object oriented programming language to communicate
with a computer system. However, the program(s) may be implemented
in assembly or machine language, if desired. In any case, the
language may be a compiled or interpreted language, and combined
with hardware implementations.
[0078] It should be understood that many of the functional units
described in this specification have been labeled as modules, in
order to more particularly emphasize their implementation
independence. For example, a module may be implemented as a
hardware circuit comprising custom VLSI circuits or gate arrays,
off-the-shelf semiconductors such as logic chips, transistors, or
other discrete components. A module may also be implemented in
programmable hardware devices such as field programmable gate
arrays, programmable array logic, programmable logic devices or the
like.
[0079] Modules may also be implemented in software for execution by
various types of processors. An identified module of executable
code may, for instance, comprise one or more physical or logical
blocks of computer instructions, which may, for instance, be
organized as an object, procedure, or function. Nevertheless, the
executables of an identified module need not be physically located
together, but may comprise disparate instructions stored in
different locations which, when joined logically together, comprise
the module and achieve the stated purpose for the module.
[0080] Indeed, a module of executable code may be a single
instruction, or many instructions, and may even be distributed over
several different code segments, among different programs, and
across several memory devices. Similarly, operational data may be
identified and illustrated herein within modules, and may be
embodied in any suitable form and organized within any suitable
type of data structure. The operational data may be collected as a
single data set, or may be distributed over different locations
including over different storage devices, and may exist, at least
partially, merely as electronic signals on a system or network. The
modules may be passive or active, including agents operable to
perform desired functions.
[0081] Reference throughout this specification to "one embodiment"
or "an embodiment" means that a particular feature, structure, or
characteristic described in connection with the embodiment is
included in at least one embodiment of the present invention. Thus,
appearances of the phrases "in one embodiment" or "in an
embodiment" in various places throughout this specification are not
necessarily all referring to the same embodiment.
[0082] As used herein, a plurality of items, structural elements,
compositional elements, and/or materials may be presented in a
common list for convenience. However, these lists should be
construed as though each member of the list is individually
identified as a separate and unique member. Thus, no individual
member of such list should be construed as a de facto equivalent of
any other member of the same list solely based on their
presentation in a common group without indications to the contrary.
In addition, various embodiments and example of the present
invention may be referred to herein along with alternatives for the
various components thereof. It is understood that such embodiments,
examples, and alternatives are not to be construed as defacto
equivalents of one another, but are to be considered as separate
and autonomous representations of the present invention.
[0083] Furthermore, the described features, structures, or
characteristics may be combined in any suitable manner in one or
more embodiments. In the following description, numerous specific
details are provided, such as examples of materials, fasteners,
sizes, lengths, widths, shapes, etc., to provide a thorough
understanding of embodiments of the invention. One skilled in the
relevant art will recognize, however, that the invention can be
practiced without one or more of the specific details, or with
other methods, components, materials, etc. In other instances,
well-known structures, materials, or operations are not shown or
described in detail to avoid obscuring aspects of the
invention.
[0084] While the forgoing examples are illustrative of the
principles of the present invention in one or more particular
applications, it will be apparent to those of ordinary skill in the
art that numerous modifications in form, usage and details of
implementation can be made without the exercise of inventive
faculty, and without departing from the principles and concepts of
the invention. Accordingly, it is not intended that the invention
be limited, except as by the claims set forth below.
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