U.S. patent application number 15/321783 was filed with the patent office on 2017-06-08 for methods for enb, ue uplink transmission and reception.
This patent application is currently assigned to MEDIATEK SINGAPORE PTE. LTD.. The applicant listed for this patent is Feifei SUN, Xiangyang ZHUANG. Invention is credited to Feifei SUN, Xiangyang ZHUANG.
Application Number | 20170164350 15/321783 |
Document ID | / |
Family ID | 55063534 |
Filed Date | 2017-06-08 |
United States Patent
Application |
20170164350 |
Kind Code |
A1 |
SUN; Feifei ; et
al. |
June 8, 2017 |
METHODS FOR ENB, UE UPLINK TRANSMISSION AND RECEPTION
Abstract
Methods and apparatus are provided for narrowband UEs. In one
novel aspect, frequency hopping is used. The UE stays on the first
frequency band for consecutive number of subframes before hopping
to another frequency band. In another embodiment, the first set of
resource elements and the second set of resource elements are
discontinued with a gap in the time domain. In another novel
aspect, the UE obtains sub-band information and a resource index
and generates a communication channel for data frame transmission
and receiving. In one embodiment, the UE further acquires the
sub-band set information through system information. In yet another
embodiment, the resource index is acquired from DCI. In yet another
novel aspect, resource blocks are selected for a PUCCH for a
narrowband UE. The UE determines an operating sub-band information
and selects one or more narrowband regions for the PUCCH.
Inventors: |
SUN; Feifei; (Beijing,
CN) ; ZHUANG; Xiangyang; (Lake Zurich, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SUN; Feifei
ZHUANG; Xiangyang |
Beijing
Lake Zurich |
IL |
CN
US |
|
|
Assignee: |
MEDIATEK SINGAPORE PTE.
LTD.
Singapore
SG
|
Family ID: |
55063534 |
Appl. No.: |
15/321783 |
Filed: |
July 10, 2015 |
PCT Filed: |
July 10, 2015 |
PCT NO: |
PCT/CN2015/083807 |
371 Date: |
December 23, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 5/0007 20130101;
H04W 72/0406 20130101; H04W 72/1263 20130101; H04L 5/0044 20130101;
H04L 27/2636 20130101; H04W 72/0453 20130101; H04L 5/0012 20130101;
H04L 1/1812 20130101; H04L 5/0053 20130101; H04W 76/27 20180201;
H04W 72/02 20130101; H04L 1/1854 20130101; H04L 5/003 20130101;
H04L 27/2607 20130101; H04W 74/0808 20130101; H04W 72/0446
20130101; H04L 5/00 20130101; H04L 5/0028 20130101; H04L 5/0048
20130101; H04W 72/0413 20130101; H04W 72/042 20130101 |
International
Class: |
H04W 72/04 20060101
H04W072/04; H04L 5/00 20060101 H04L005/00; H04W 72/02 20060101
H04W072/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 11, 2014 |
CN |
PCTCN2014/082096 |
Claims
1. A method, comprising: generating a communication channel by a
user equipment (UE) in a wireless communication network, wherein
the communication channel is mapped to a sequence of resource
elements, each resource element is with a frequency sub-band of a
system frequency bandwidth and a time domain subframe number;
selecting a first set of resource elements with a first frequency
band for consecutive number N of subframes for the communication
channel, wherein the first frequency band is a sub-band of the
system bandwidth; hopping to a second set of resource elements with
a second frequency band every N consecutive number of subframes for
the communication channel, wherein the second frequency band is a
sub-band of the system bandwidth, and wherein the first and the
second frequency band are different; and sending or receiving
information bits on the communication channel.
2. The method of claim 1, wherein N is greater than or equals to
the number of subframes needed for cross subframe channel
estimation for the UE.
3. The method of claim 1, wherein the first and second frequency
bands are determined based on a type of the UE.
4. The method of claim 1, wherein the first set of resource
elements and the second set of resource elements are discontinued
with a gap in the time domain.
5. The method of claim 4, wherein the gap number of subframes is at
least based on a frequency re-tuning time for the UE.
6. The method of claim 4, resource elements in the gap time domain
are occupied by one or more different UEs.
7. A method, comprising: obtaining sub-band information and a
resource index by a user equipment (UE) in a wireless network;
generating a communication channel based on the obtained sub-band
information and the resource index; and sending or receiving
information bits on the communication channel.
8. The method of claim 7, wherein prior to obtaining a sub-band
information and a resource index further comprise: obtaining a set
of narrowband information by the UE, wherein the set of narrowband
information includes one or more sub-band information, and wherein
each sub-band is a subset of contiguous resource blocks in a system
bandwidth.
9. The method of claim 8, wherein the set of narrowband information
is obtained through system information.
10. The method of claim 7, wherein the sub-band information is
determined based on at least one sub-band conditions, comprising: a
channel condition, a transmission mode, a transport block size, a
latency requirement, a UE category, a traffic type, timing advance
requirement, and transmitting random access preamble
requirement.
11. The method of claim 7, wherein the sub-band information is
indicated in downlink control information (DCI).
12. The method of claim 7, wherein the sub-band information is
configured through radio resource control (RRC).
13. The method of claim 12, wherein the resource index is indicated
in downlink control information (DCI).
14. The method of claim 13, wherein the resource index is a
physical resource block (PRB) index, and wherein PRB index is a
relative index in the sub-band.
15. The method of claim 7, wherein the resource index is a physical
resource block (PRB) index, and wherein PRB index is defined for
the system bandwidth.
16. A method, comprising: determining an operating sub-band
information by a user equipment (UE) in a wireless network, wherein
the operating sub-band is smaller than a system bandwidth, and
wherein the UE operates in the sub-band; selecting one or more
narrowband regions for a physical uplink control channel (PUCCH)
for the UE based on the determined operating sub-band information,
wherein the one or more selected narrowband regions are at
corresponding known locations of the operating sub-band; and
sending control information to the wireless network on the
PUCCH.
17. The method of claim 16, wherein the selected one or more
narrowband regions are at one or two edges of the operating
sub-band of the UE.
18. The method of claim 16, wherein resource blocks of the selected
one or more narrowband regions occupy different frequency
bands.
19. The method of claim 18, wherein the PUCCH stays on a same
frequency band for a consecutive number N of subframes before
hopping to a different frequency.
20. The method of claim 19, wherein one or more subframes in the
selected narrowband regions are guard subframes.
21. The method of claim 20, wherein the guard subframes are at
least based on a frequency re-tuning time of the UE.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a national stage application of
International Application No. PCT/CN2015/083807 filed Jul. 10,
2015, which is a continuation-in-part of International Application
No. PCT/CN2014/082096 entitled "Method for eNB, UE Uplink
transmission and reception" filed on Jul. 11, 2014; the subject
matter of which is incorporated herein by reference.
TECHNICAL FIELD
[0002] This disclosure relates generally to wireless communications
and, more particularly, to uplink transmission and reception from
different UEs.
BACKGROUND
[0003] Recently, there are more and more diverse requirements to
the wireless communication system and correspondingly UE may have
different capabilities. For example, in 3GPP LTE Release 12, a new
UE category is defined with the capabilities of single Rx, limited
to 1000 bit Transport Block Size (TBS) for unicast channel, and
also can support half duplex FDD with single oscillator. The new
defined UE category is for machine to machine (M2M) communication
which has small data package but requires low device cost. On the
other hand, a massive number of M2M device subscribers are
predicted within dozens of years. In Rel-10, 3GPP studied on
Machine Type Communication (MTC) congestion for RAN and core
network. Furthermore, some of the M2M devices are very often
installed in the basements of residential buildings or locations
shielded by foil-backed insulations, metalized windows, or
traditional thick-walled building constructions, such as metering.
The coverage is a big issue for these metering. 3GPP RAN1 Rel-12
studied on 20 dB coverage extension for MTC devices. However, the
solutions needs hundreds of repetitions, which is neither not very
efficient from cell throughput point of view nor for device power
consumption. On the other hand, in wireless network, some other
applications such as vehicle to vehicle communication may require
very short latency. These quite diverse requirements need a more
efficient communication system. The benefit of wireless network
transmission and reception technique is not limited to the examples
above.
SUMMARY
[0004] Methods and apparatus are provided for the base station to
handle different uplink channel from different UEs. Methods and
apparatus are provided for the UE with different downlink and
uplink channel and for the UE with narrowband operation.
[0005] In one novel aspect, the UE receives a downlink transmission
and transmits an uplink channel with has different frequency domain
subcarrier spacing and different time domain symbol duration. In
one embodiment, the uplink channel is a SC-FMDA-based channel. In
another embodiment, for uplink channels with large enough CP, the
UE transmits the uplink channel without any transmission of the
random access preamble and/or timing advance information from the
eNB. In yet another embodiment, the base station receives a first
uplink channel from a first UE and receives a second uplink channel
from a second UE. The base station processes the different uplink
channel by first applying filter process. In one embodiment, the
first and the second uplink channel is not different and not
overlapping. In yet another embodiment, the base station indicates
to a second UE that the uplink resource elements. In one
embodiment, the base station selects a second uplink subcarrier for
the second UE.
[0006] In another novel aspect, frequency hopping is used. In one
embodiment, the UE stays on the first frequency band for
consecutive number of subframes before hopping to another frequency
band. In one embodiment, the number of consecutive subframes is at
least based on the number of subframes needed for cross subframe
channel estimation. In another embodiment, the first set of
resource elements and the second set of resource elements are
discontinued with a gap in the time domain, wherein there is no
resource element allocated for the communication channel for a gap
number of subframes.
[0007] In another novel aspect, the UE obtains sub-band information
and a resource index and generates a communication channel for data
frame transmission and receiving. In one embodiment, the UE further
acquires the sub-band set information through system information.
In yet another embodiment, the resource index is acquired from DCI.
In one embodiment, the UE acquires sub-band information in the
wireless network. In one embodiment, the resource index is a PRB.
In another embodiment, different resource blocks are selected for
PUCCH. In one embodiment, PUCCH stays on a same frequency band for
a consecutive number N of subframes before hopping to a different
frequency.
[0008] In yet another novel aspect, resource blocks are selected
for the PUCCH for a narrowband UE. The UE determines an operating
sub-band information and selects one or more narrowband regions for
the PUCCH.
[0009] Other embodiments and advantages are described in the
detailed description below. This summary does not purport to define
the invention. The invention is defined by the claims.
BRIEF DESCRIPTION OF DRAWINGS
[0010] The accompanying drawings, where like numerals indicate like
components, illustrate embodiments of the invention.
[0011] FIG. 1 illustrates a wireless communication system in
accordance with embodiments of the current invention.
[0012] FIG. 2 illustrates an exemplary diagram of the UE receiving
a downlink channel with downlink subcarrier spacing and
transmitting an uplink channel with uplink subcarrier spacing in
accordance with embodiments of the current invention.
[0013] FIG. 3 illustrates an exemplary diagram of generating a
SC-FDMA based uplink channel in accordance with embodiments of the
current invention.
[0014] FIG. 4 illustrates an exemplary diagram of different
subcarrier spacing for reference signals and data signals in
accordance with embodiments of the current invention.
[0015] FIG. 5 illustrates an exemplary diagram of eNB receiving
uplink channels from multiple UEs with different subcarrier spacing
in accordance with embodiments of the current invention.
[0016] FIG. 6 illustrates an exemplary diagram of multiplexing
schemes of different UEs in accordance with embodiments of the
current invention.
[0017] FIG. 7 illustrates an exemplary diagram of eNB receiving
uplink channels with different subcarrier spacing in accordance
with embodiments of the current invention.
[0018] FIG. 8 illustrates an exemplary diagram of symbol length and
CP length of different subcarrier spacing values in accordance with
embodiments of the current invention.
[0019] FIG. 9 illustrates an exemplary diagram of resource
grid.
[0020] FIG. 10 illustrates exemplary diagrams of different
definitions of resource block with different subcarrier spacing
values in accordance with embodiments of the current invention.
[0021] FIG. 11A illustrates top level flow chart for the UE and/or
eNB to decide subcarrier spacing in accordance with embodiments of
the current invention.
[0022] FIG. 11B illustrates an exemplary diagram of UE and/or eNB
to decide subcarrier spacing in accordance with embodiments of the
current invention.
[0023] FIG. 11C illustrates behaviors of UE and/or eNB to decide
subcarrier spacing in accordance with embodiments of the current
invention.
[0024] FIG. 12A illustrates an exemplary diagram of the eNB
acquires information of UEs to decide subcarrier spacing in
accordance with some embodiments of the current invention.
[0025] FIG. 12B illustrates an exemplary diagram of the eNB
acquires information of UEs to decide subcarrier spacing in
accordance with some embodiments of the current invention.
[0026] FIG. 13 illustrates an exemplary diagram of radio resource
regions for different subcarrier spacing values in accordance with
embodiments of the current invention.
[0027] FIG. 14 illustrates an exemplary diagram of how UE obtaining
the uplink configurations including radio resource regions for
different subcarrier spacing values and uplink assignment in
accordance with embodiments of the current invention.
[0028] FIG. 15A illustrates an exemplary diagram of UL assignment
indication to the UE for the uplink subcarrier spacing or the
second uplink subcarrier spacing in accordance with embodiments of
the current invention.
[0029] FIG. 15B illustrates an exemplary diagram of UL assignment
indication to the UE for the uplink subcarrier spacing or the
second uplink subcarrier spacing in accordance with embodiments of
the current invention
[0030] FIG. 16 illustrates some exemplary diagrams of subcarrier
spacing configuration for different UEs with some embodiments of
the current invention.
[0031] FIG. 17 illustrates some exemplary diagrams of resource
allocations for different subcarrier spacing in accordance with
some embodiments of the current invention.
[0032] FIG. 18 illustrates some exemplary diagrams of control
channel design for narrow RF bandwidth UEs in accordance with some
embodiments of the current invention.
[0033] FIG. 19 illustrates some exemplary diagrams of HARQ timing
in accordance with some embodiments of the current invention.
[0034] FIG. 20 illustrates some exemplary diagram of PRACH
configuration for normal coverage UE and coverage enhancement mode
UE with some embodiments of the current invention.
[0035] FIG. 21 illustrates some exemplary diagrams of PUCCH
resource in time-frequency domain and code domain with some
embodiments of the current invention.
[0036] FIG. 23 shows an exemplary flow chart for a base station to
handle the uplink channel occupies a set of uplink resource
elements that are different from the downlink resource elements in
accordance with embodiments of the current invention.
[0037] FIG. 24 shows an exemplary flow chart for a UE to perform
frequency hopping for narrowband configuration in accordance with
embodiments of the current invention.
[0038] FIG. 25 shows an exemplary flow chart for a UE to perform
resource allocation for narrowband configuration in accordance with
embodiments of the current invention.
[0039] FIG. 26 shows an exemplary flow chart for a UE to perform
PUCCH selection for narrowband configuration in accordance with
embodiments of the current invention.
[0040] Corresponding numerals and symbols in the different figures
generally refer to corresponding parts unless otherwise indicated.
The figures are drawn to clearly illustrate the relevant aspects of
the embodiments and are not necessarily drawn to scale.
DETAILED DESCRIPTION
[0041] Reference will now be made in detail to some embodiments of
the invention, examples of which are illustrated in the
accompanying drawings.
[0042] FIG. 1 illustrates a wireless communication system in
accordance with some embodiments. Wireless communication system 100
includes one or more wireless networks, each of the wireless
communication network has a fixed base infrastructure unit, such as
wireless communications base stations 102, 103, and 104, forming
wireless networks distributed over a geographical region. The base
unit may also be referred to as an access point, an access
terminal, a base station, a Node-B, an eNode-B, or by other
terminology used in the art. Each of the receiving wireless
communications base stations 102, 103, and 104 serves a geographic
area. Backhaul connections 113, 114 and 115 connect the
non-co-located wireless communications stations, such as base
station 102, 103, and 104. These backhaul connections can be either
ideal or non-ideal
[0043] A wireless communications device, UE 101 in wireless network
100 is served by base station 102 via uplink 111 and downlink 112.
Other wireless communications devices, UE 105, 106, 107, and 108
are served by different base stations. UE 105 and 106 are served by
base station 102. UE 107 is served by base station 104. UE 108 is
served by base station 103.
[0044] In one embodiment, the eNB can serve different kind of UEs.
UE 101 and 106 may belong to different categories, such as having
different RF bandwidth or different subcarrier spacing. UE
belonging to different categories may be designed for different use
cases or scenarios. For example, some use case such as Machine Type
Communication (MTC) may require very low throughput, delay torrent,
the traffic packet size may be very small (e.g., 1000 bit per
message), extension coverage. Some other use case, e.g. intelligent
transportation system, may be very strict with latency, e.g. orders
of 1 ms of end to end latency. Different UE categories may be
introduced for these diverse requirements. Different frame
structures or system parameters may also be used in order to
achieve some special requirement. For example, different UEs may
have different RF bandwidths, subcarrier spacing values, omitting
some system functionalities (e.g., random access, CSI feedback), or
use physical channels/signals for the same functionality (e.g.,
different reference signals).
[0045] FIG. 1 further shows simplified block diagrams of UE 101 and
base station 102 in accordance with the current invention.
[0046] Base station 102 has an antenna 126, which transmits and
receives radio signals. A RF transceiver module 123, coupled with
the antenna, receives RF signals from antenna 126, converts them to
baseband signals and sends them to processor 122. RF transceiver
123 also converts received baseband signals from processor 122,
converts them to RF signals, and sends out to antenna 126.
Processor 122 processes the baseband signals, generates a
communication channel and invokes different functional modules to
perform features in base station 102. Memory 121 stores program
instructions and data 124 to control the operations of base station
102.
[0047] Base station 102 also includes a set of control modules that
carry out functional tasks. A resource allocation module 181
handles resource allocation related functions including sub-bands
information for one or more UEs. A frequency hopping module 182
that handles UE frequency hopping related functions. A PUCCH module
183 handles related functions for PUCCH of narrowband UEs. A
sub-carrier module 184 handles sub-carrier spacing related
functions for one or more UEs. A HARQ module handles HARQ related
functions for narrowband UEs. A random access module handles random
access or a contention based uplink message from UEs.
[0048] UE 101 has an antenna 135, which transmits and receives
radio signals. A RF transceiver module 134, coupled with the
antenna, receives RF signals from antenna 135, converts them to
baseband signals and sends them to processor 132. RF transceiver
134 also converts received baseband signals from processor 132,
converts them to RF signals, and sends out to antenna 135.
Processor 132 processes the baseband signals and invokes different
functional modules to perform features in UE 101. Memory 131 stores
program instructions and data 136 to control the operations of UE
101.
[0049] UE 101 also includes a set of control modules that carry out
functional tasks. A resource allocation handler 191 obtains
resource allocation comprising sub-band information and a resource
index and generates a communication channel. A frequency hopping
handler 192 handles frequency hopping related functions for
narrowband UEs. A PUCCH handler 193 handles PUCCH allocation for
narrowband UEs. A subcarrier handler 194 handles subcarrier spacing
related functions for UEs. A HARQ module handles HARQ related
functions for narrowband UEs. A random access module handles random
access or a contention based uplink message related functions.
[0050] In one embodiment, the wireless communication system 100
utilizes an OFDMA or a multi-carrier based architecture including
Adaptive Modulation and Coding (AMC) on the downlink and next
generation single-carrier (SC) based FDMA architecture for uplink
transmissions. SC based FDMA architectures include Interleaved FDMA
(IFDMA), Localized FDMA (LFDMA), and DFT-spread OFDM (DFT-SOFDM)
with IFDMA or LFDMA. In OFDMA based systems, UE 103 and 110 are
served by assigning downlink or uplink radio resources that
typically comprises a set of sub-carriers over one or more OFDM
symbols. Exemplary OFDMA-based protocols include the developing
Long Term Evolution (LTE) of the 3GPP UMTS standard and the IEEE
802.16 standard. The architecture may also include the use of
spreading techniques such as multi-carrier CDMA (MC-CDMA),
multi-carrier direct sequence CDMA (MC-DS-CDMA), Orthogonal
Frequency and Code Division Multiplexing (OFCDM) with one or two
dimensional spreading. In other embodiments, the architecture may
be based on simpler time and/or frequency division
multiplexing/multiple access techniques, or a combination of these
various techniques. In alternate embodiments, the wireless
communication system 100 may utilize other cellular communication
system protocols including, but not limited to, TDMA or direct
sequence CDMA.
[0051] For example, in the 3GPP LTE system based on SC-FDMA uplink,
the radio resource is partitioned into subframes, and each of the
subframes comprises 2 slots and each slot has 7 SC-FDMA symbols in
the case of normal Cyclic Prefix (CP). For each user, each SC-FDMA
symbol further comprises a number of subcarriers depending on the
uplink assignment. The basic unit of the radio resource grid is
called Resource Element (RE) which spans an SC-FDMA subcarrier over
one SC-FDMA symbol.
[0052] Each UE gets an assignment, i.e., a set of REs in a Physical
Uplink Shared Channel (PUSCH), when an uplink packet is sent from a
UE to an eNB. The UE gets the downlink and uplink assignment
information and other control information from its Physical
Downlink Control Channel (PDCCH) or Enhanced Physical Downlink
Control Channel (EPDCCH) whose content is dedicated to that UE. The
uplink assignment is indicated in downlink control information
(DCI) in PDCCH/EPDCCH. Usually, the uplink assignment indicated the
resource allocation within one certain subframe, for example k+4
subframe if DCI is received in subframe k for FDD and for TDD, the
timing relationship is given in a table in TS 36.213. TTI bundling
is used in uplink transmission in LTE system to improve uplink
coverage. If TTI bundle is enabled, one uplink assignment indicates
several subframes to transmit one transport block using different
redundancy version (RV).
[0053] Uplink control information is transmitted in Physical Uplink
Control Channel (PUCCH) or transmitted with or without a transport
block in PUSCH. UCI includes HARQ, scheduling request (SR), channel
status information (CSI). PUCCH is allocated the border PRBs in
uplink system bandwidth. Frequency diversity gain for PUCCH is
obtained by frequency hopping between two slots in one subframe.
Code Division Multiplexing (CDM) is used for PUCCH multiplexing
between different UEs on the same radio resource.
[0054] In one embodiment of the disclosure, a method for UE to
transmit to an eNB an uplink channel carrying data or control
information bits is provided, the method comprising: receiving an
OFDM-based downlink channel occupying a set of downlink resource
elements, where each downlink resource element has a downlink
subcarrier spacing in the frequency domain and a downlink symbol
duration in the time domain; generating a SC-FDMA based uplink
channel from the information bits, where the uplink channel
occupies a set of uplink resource elements and each uplink resource
element has a uplink subcarrier spacing in the frequency domain
different from the downlink subcarrier spacing, and a uplink symbol
duration in the time domain different from the downlink symbol
duration; and transmitting the SC-FDMA based uplink channel. In one
embodiment, the information bits are uplink data information bits.
In another embodiment, the information bits are uplink control
information bits.
[0055] In one embodiment, generating a SC-FDMA based uplink channel
further comprising: mapping the information bits to a block of QPSK
or QAM symbols; transforming the block of QPSK/QAM symbols via DFT
to obtain multiple complex-valued symbols; mapping the multiple
complex-valued symbols to the set of uplink resource elements. The
uplink channel may further include reference signals for
information bits demodulation. The location and waveform of the
reference signals are pre-known by both eNB and UE, which can be
configured via RRC message, or indicated with uplink assignment or
pre-defined in the specification. The subcarrier spacing values of
the reference signals can be same or different with the uplink
subcarrier spacing for the modulated information bits. The
modulated information bits and reference singles can be multiplexed
in frequency domain or time domain.
[0056] For the sake of eNB decoding complexity and signaling
overhead, in one embodiment, the uplink subcarrier spacing is
pre-defined. On the other hand, in order to increase the
flexibility, in another embodiment, the uplink subcarrier spacing
is configured to the UE by higher layer signaling. For example, UE
receives system information to obtain the uplink subcarrier spacing
of the uplink resource elements. In another example, UE receives
the RRC message to obtain the uplink subcarrier spacing of the
uplink resource elements. In this example, the uplink subcarrier
spacing can be uni-casted or group-casted. And the uplink
subcarrier spacing information can be UE-specific. Alternatively,
it can be cell-specific. In another embodiment, for some special
cases, the uplink subcarrier spacing can be dynamically configured.
For example, UE can receive an uplink assignment message to obtain
the uplink subcarrier spacing of the uplink resource elements.
Sometimes, UE needs to obtain the uplink subcarrier spacing
information with both higher layer singling and physical layer
signaling. For example, UE receives a uplink subcarrier spacing
value set in a higher layer signaling, e.g., in System Information
(SI), and the uplink subcarrier spacing is indicated by a physical
layer signaling, e.g. in Downlink Control Information (DCI).
[0057] Alternatively, the uplink subcarrier spacing value set can
be pre-defined and known to the UE. Another example for UE to
obtain the uplink subcarrier spacing is that UE obtains the uplink
subcarrier spacing information by obtaining the radio resource
region (e.g., a sub-band) for its uplink transmission. UE obtains
the uplink subcarrier spacing value set and the radio resource
region corresponding to each uplink subcarrier spacing in the
uplink subcarrier spacing set. The corresponded radio resource
region can be configured by higher layer signaling (e.g., in SI),
which can be changed semi-statically. Alternatively, the
corresponded radio resource region can be defined in specification.
The corresponding radio resource region can be UE-specific, which
means different UEs can have different radio resource regions to
transmit with the same uplink subcarrier spacing, or different UEs
may transmit with the same uplink subcarrier spacing in same radio
resource region or different radio resource regions. Alternatively,
the corresponded radio resource region can be cell-specific, which
means all the UEs in the cell will transmitted uplink waveform with
the same uplink subcarrier value. Since each value in the uplink
subcarrier spacing value set is associated with one corresponding
radio resource region, e.g., a sub-band, the uplink subcarrier
spacing can be implied by the resource allocation for the uplink
assignment (e.g., by a physical layer signaling) or the configured
corresponding radio resource region (e.g., by a higher layer
signaling to configure which radio resource is configured to the UE
for uplink transmission). Note that, not all the UEs in the cell
need to know all the subcarrier spacing values. eNB is expected to
handle it if some UEs do not know more than one subcarrier spacing
values. For example, legacy UEs may assume subcarrier spacing is 15
kHz for uplink data channel and control channel. Also noted that,
in another embodiment, a default uplink subcarrier spacing can be
used by the UE, which is the same with the downlink subcarrier
spacing, until the UE gets an indication of a new uplink subcarrier
spacing value (e.g., the uplink subcarrier spacing), e.g., by RRC
signaling or physical layer signaling.
[0058] In another embodiment of the disclosure, a method for an eNB
to receive uplink channels carrying data or control information
bits is provided, the method comprising: receiving a first uplink
channel from a first UE on a first set of uplink resource elements
where each uplink resource element has a first uplink subcarrier
spacing in the frequency domain and a first uplink symbol duration
in the time domain; and receiving a second uplink channel from a
second UE on a second set of uplink resource elements where each
uplink resource element has a second uplink subcarrier spacing in
the frequency domain differing from the first uplink subcarrier
spacing, and a second uplink symbol duration in the time domain
differing from the first uplink symbol duration. In one example,
the uplink channel carries the uplink data information bits from
the UE. In another example, the uplink channel carries the uplink
control information bits from the UE. In one example, the uplink
channel is based on SC-FDMA.
[0059] The multiplexing scheme of two UEs, e.g. the first UE and
the second UE can be frequency division multiplexed (FDM). For
example, the first set of uplink resource elements and second set
of uplink resource elements are not overlapping in the frequency
domain, but occupy the same time duration. More than one UE may use
the same set of uplink resource elements for the transmissions of
uplink channels with the second uplink subcarrier spacing. These
more than one UE can be code-division multiplexed (CDM) or space
division multiplexed (SDM) using the same set of uplink resource
elements. Multiple UEs using the second uplink subcarrier spacing
can also be frequency division multiplexed (FDM) by using different
sets of uplink resource elements. In an example, the first uplink
subcarrier is the same as the downlink subcarrier spacing of the
downlink resource elements.
[0060] Similar as previous embodiments, the second subcarrier
spacing is pre-defined. Alternatively, eNB configures the second
subcarrier spacing by higher layer signaling or in physical layer
signaling, e.g. SI, or in RRC message. And the second subcarrier
spacing information can be UE-specific or cell-specific. In another
embodiment, eNB configure the uplink subcarrier spacing value set
in higher layer signaling (e.g., in system information) and further
indicate the second subcarrier spacing value later via a higher
layer signaling (e.g., in RRC message) or a physical layer
signaling (e.g., in DCI). Alternatively, the uplink subcarrier
spacing value set can be pre-defined and known to the UE. In
another embodiment, eNB can indicate explicit or implicit the
second subcarrier spacing to the UE, for example by the second set
of uplink resource elements.
[0061] In another embodiment of the disclosure, a method for an eNB
to receive uplink channels carrying data or control information
bits, the method comprising: receiving an mixed time domain signal
on an uplink system bandwidth from the first UE and the second UE;
discarding a first length of cyclic prefix (CP); transforming the
mixed time domain signal with the first uplink symbol duration
after the first length of CP on the uplink system bandwidth into a
first frequency domain signal based on the first uplink subcarrier
spacing; repeating the discarding CP and the transforming mixed
time domain signal until obtaining all of the first set of uplink
resource elements; selecting the signals on the first set of uplink
resource elements and decoding the signals on the first set of
uplink resource elements to obtain the first uplink channel from
the first UE. The method further comprising: filtering out a second
time domain signal on an uplink sub-band within the uplink system
bandwidth, wherein the uplink sub-band including all of the second
set of uplink resource elements; discarding a second length of CP
and transforming the second time domain signal with the second
uplink symbol duration after the second length of CP on the uplink
sub-band into a second frequency domain signal based on the second
uplink subcarrier spacing; repeating discarding CPs and
transforming the second time domain signals until obtaining all of
the second set of uplink resource elements; picking up the signals
on the second set of uplink resource elements and decoding the
signals on the second set of uplink resource elements to obtain the
second uplink channel from the second UE. In one example, the first
and second length of CP can be the same or different.
[0062] Different subcarrier spacing values will result in different
symbol durations. For example, the first uplink subcarrier spacing
in frequency domain corresponds with the first symbol duration in
time domain, and the second uplink subcarrier spacing corresponds
with the second symbol duration in time domain. Similarly,
different uplink and downlink subcarrier spacing values also result
in different symbol durations. The definition of slot/subframe
(e.g., slot and subframe length are 0.5 ms and 1 ms respectively in
LTE system) can be reused for different subcarrier spacing values.
This means the number of symbol(s) is different in one slot or one
subframe with different subcarrier spacing values. For example, for
15 kHz subcarrier spacing, six or seven symbols can fit in one slot
(i.e., 0.5 ms) and for 3.75 kHz subcarrier spacing, only 1.5
symbols can fit in one slot. Alternatively, different lengths of
subframe/slot can be defined for different subcarrier spacing
values. For example, in order to keep six or seven symbols for 3.75
kHz in each slot, one slot can be defined as 2 ms. Cyclic prefix
(CP) is used to avoid interference and the length needs to cover
the maximum delay spread of the fading channel if the timing
advance is introduced to compensate the Round Trip Time (RTT) delay
so that the uplink signals from different UEs can arrive at the
receiver almost the same time. A smaller subcarrier spacing value
gives a chance to design a long CP with the same overhead. For
example, with 3.75 kHz subcarrier spacing, 66.7 .mu.s can be used
as one CP compared with 5.1/4.7 .mu.s CP length for 15 kHz
subcarrier spacing. With a longer CP for uplink, the Timing Advance
(TA) can be eliminated. In one embodiment, UE transmits the SC-FDMA
based uplink channel without obtaining any TA information from the
eNB. In LTE system, a preamble with a long CP is designed for
Random Access Channel (RACH) to let eNB to estimate the TA from
each UE. If long CP is used for uplink data or control information
transmission, there is no need for UE to transmit random access
preamble for TA. That is, UE transmits the SC-FDMA based uplink
channel without any transmission of the random access preamble.
Correspondingly eNB receives an uplink channel carrying data or
control information bits without receiving the random access
preamble, or without any configuration of TA to UEs.
[0063] In another example, the method for an eNB to receive uplink
channels carrying data or control information bits is provided, the
method further comprising: indicating to the second UE the second
set of uplink resource elements where each uplink resource element
has the second uplink subcarrier spacing in the frequency domain
differing from the first uplink subcarrier spacing, and the second
symbol duration in the time domain differing from the first symbol
duration based on at least one condition. eNB needs to distinguish
which UE needs to be indicated with the second uplink subcarrier
spacing. In one example, the eNB indicates the second UE to use the
second uplink subcarrier spacing based on a report from the second
UE. In another example, the eNB indicates the second UE to use the
second uplink subcarrier spacing based on a message from core
network. Alternatively, the second uplink subcarrier is selected by
the second UE. The second uplink subcarrier can be selected from
the uplink subcarrier spacing value set. When both of the
embodiments for the second UE to select the second subcarrier
spacing or for the eNB to indicate to the second UE the second
uplink subcarrier spacing, based on the at least one condition. The
at least one condition is at least one of the following: a channel
condition; a transmission mode; a TBS; a latency requirement; a UE
category; a traffic type; the need of TA; the need of transmitting
random access preamble. For examples, the eNB indicates to the
second UE the second uplink subcarrier spacing if the uplink
channel condition from the second UE is worse than a threshold; or
if the buffer status report from the second UE is smaller than a
threshold; or if the latency requirement of the second UE is relax
enough; or if the second UE belong to a special UE category; or if
the traffic type of the second UE belong to a special traffic type;
or if the UE identify of the second UE belongs to a special group;
or if the second UE does not need TA before uplink transmission for
data or control information; or if the eNB does not need to receive
the random access preamble from the second. Similar conditions are
also applied when the second UE selects the second uplink
subcarrier spacing. The at least one condition can be configured by
higher layer signaling or pre-defined in the specification. For
example, for a special UE category, the subcarrier spacing value is
3.75 kHz but for other UE categories, the subcarrier spacing value
is 15 kHz. Noted that, in another embodiment, a default subcarrier
spacing (e.g., the first uplink subcarrier spacing) can be
pre-defined to UE until UE gets an indication of a new subcarrier
spacing value (e.g., the second uplink subcarrier spacing), e.g.,
by RRC signaling or physical layer signaling.
[0064] FIG. 2 illustrates an example of UE receiving a downlink
channel with downlink subcarrier spacing and transmitting an uplink
channel with uplink subcarrier spacing in accordance with some
embodiments of current invention. In one embodiment of the
disclosure, a method for UE 201 to transmit to an eNB 202 an uplink
channel 203 carrying data or control information bits, the method
comprising: receiving an OFDM-based downlink channel 204 occupying
a set 205 of downlink resource elements 206, where each downlink
resource element 206 has a downlink subcarrier spacing 211 in the
frequency domain and a downlink symbol duration 212 in the time
domain (step 251); generating a SC-FDMA based uplink channel 203
from the information bits, where the uplink channel 203 occupies a
set 207 of uplink resource elements 208 and each uplink resource
element 208 has a uplink subcarrier spacing 213 in the frequency
domain differing from the downlink subcarrier spacing 211, and a
uplink symbol duration 214 in the time domain differing from the
downlink symbol duration 212 (step 252); and transmitting the
uplink channel 203, e.g., SC-FDMA based uplink channel to eNB 202,
(step 253). And FIG. 2 also illustrates a flow chart of UE
receiving a downlink channel with downlink subcarrier spacing and
receiving an uplink channel with uplink subcarrier spacing.
Description in details refers to the above.
[0065] FIG. 3 illustrates an example of generating a SC-FDMA based
uplink channel in accordance with some embodiments of current
invention. In FIG. 3, generating a uplink channel further
comprising: obtain the information bits in block 301, mapping the
information bits to a block of QPSK or QAM symbols in block 302;
transforming the block of QPSK/QAM symbols via DFT to obtain
complex-valued symbols in block 303; remapping the complex-valued
symbols to the set of uplink resource elements in block 305. The
uplink channel may further include reference signals 304 for
information bits demodulation. The reference signals 304 and uplink
channel are mapped to resource elements (REs), where the location
and the waveform of the reference signals 304 are pre-known by both
eNB and UE. For example, the location and waveform of the reference
signals is configured via RRC message, or indicated with uplink
assignment or pre-defined in the specification. The set of the
resource elements for uplink channel is also known by both eNB and
UE. For example, the set of the resource elements for uplink
channel is indicated in uplink assignment in DCI. IFFT can be used
to transmit frequency domain signals into time domain in block 306.
Before sending out, CP is added in block 307 to avoid
interference.
[0066] The subcarrier spacing value of the reference signals can be
same or different with the uplink subcarrier spacing for the
modulated information bits. The modulated information bits and
reference signals can be multiplexed in frequency domain or time
domain. FIG. 4 illustrates an example of different subcarrier
spacing for reference signal and data signal with some embodiments
of current invention. Data signal uses subcarrier spacing 400 while
reference signal uses subcarrier spacing 410. If subcarrier spacing
410 is larger than 400, the symbol length 420 of data signal is
longer than symbol length 430 of reference signal. However, the CP
length 440 for both data signal and reference signal can be the
same as FIG. 4 shown. Table 1 gives some examples of reference
signal design with same or different subcarrier spacing values
between reference signal and data signal. From Table 1, the
overhead of reference signal and CP is smaller if a larger
subcarrier spacing value is used for reference signal. However, the
smallest granularity of resource allocation in frequency domain to
one UE is limited by the largest subcarrier spacing. For example,
if subcarrier spacing values of data and reference signal are 3.75
kHz and 15 kHz respectively, the smallest granularity of resource
allocation in frequency domain assigned to one UE is 15 kHz, which
means four data subcarriers in frequency domain as FIG. 4
shown.
TABLE-US-00001 TABLE 1 Examples of reference signal design Date
subcarrier 3.75 kHz/ 3.75 kHz/ 2.5 kHz/ 2.5 kHz/ spacing/Symbol
266.7 .mu.s 266.7 .mu.s 400 .mu.s 400 .mu.s length CP length 66.7
.mu.s 33.3 .mu.s 100 .mu.s 44.4 .mu.s Reference signal 3.75 kHz/ 15
kHz/ 2.5 kHz/ 15 kHz/ subcarrier 266.7 .mu.s 66.7 .mu.s 400 .mu.s
66.7 .mu.s spacing & symbol length Cell radius (no 10.3 km 4.7
km 15.8 km 6.7 km timing advance) Overhead 1 RS symbol 1 RS symbol
1 RS symbol 1 RS symbol (including every 1 ms: 47% every 1 ms: 20%
every 1 ms: 60% every 1 ms: 20% reference signal 1 RS symbol 1 RS
symbol and CP) every 2 ms: 33.3% every 2 ms: 40%
[0067] FIG. 5 illustrates an example of eNB receiving uplink
channels from multiple UEs with different subcarrier spacing
according to one embodiment of current invention. The method for an
eNB 501 to receive uplink channels 502 and 504 carrying data or
control information bits, comprising: receiving a first uplink
channel 502 from a first UE 503 on a first set 506 of uplink
resource elements 507 where each uplink resource element 507 has a
first uplink subcarrier spacing 512 in the frequency domain and a
first uplink symbol duration 513 in the time domain (step 551); and
receiving a second uplink channel 504 from a second UE 505 on a
second set 508 of uplink resource elements 509 where each uplink
resource element 509 has a second uplink subcarrier spacing 514 in
the frequency domain differing from the first uplink subcarrier
spacing 512, and a second uplink symbol duration 515 in the time
domain differing from the first uplink symbol duration 513 (step
552), wherein the first uplink channel and the second uplink
channel are using the same the same RAT. In one example, the first
uplink channel and the second uplink channel are based on SC-FDMA.
In an example, the first uplink subcarrier spacing 512 is the same
as the downlink subcarrier spacing 211 of the downlink resource
elements 205 (in FIG. 2). And FIG. 5 also illustrates a flow chart
of eNB receiving uplink channels from multiple UEs with different
subcarrier spacing. Description in details refers to the above.
[0068] FIG. 6 illustrates examples of multiplexing schemes of
different UEs according to the embodiments of current invention. In
FIG. 6, the multiplexing scheme of the first UE 601 and the second
UE 603 can be Frequency Division Multiplexed (FDM). For example,
the first set 611 of uplink resource elements and the second set
612 of uplink resource elements are not overlapping in the
frequency domain, but occupy the same time duration 600, and the
first uplink subcarrier spacing 610 of the first set 611 of uplink
resource elements is different from the second uplink subcarrier
spacing 613 of the second set 612 of uplink resource elements. More
than one UE 602 and 603 may use the same set 612 of uplink resource
elements for the transmissions of uplink channels with the second
uplink subcarrier spacing 613. These more than one UE 602 and 603
can be Code Division Multiplexed (CDM) or Space Division
Multiplexed (SDM) using the same set 612 of uplink resource
elements. Multiple UE 602 and UE 604 using the second uplink
subcarrier spacing 613 can also be Frequency Division Multiplexed
(FDM) by using different sets 612 and 614 of uplink resource
elements.
[0069] FIG. 7 illustrates examples of eNB receiving uplink channels
on different sub-bands with different subcarrier spacing values
according to the embodiments of current invention. In FIG. 7, eNB
receives a mixed time domain signal 701 on an uplink system
bandwidth 704 from the first UE and the second UE; discards (by
clock 711) a first length 702 of cyclic prefix (CP)(block 711 is
optional, because block 711 could be omitted when the CP does not
need to be discards); transforms (e.g., by FFT 712) the mixed time
domain signal 701 with the first uplink symbol duration 703 after
the first length 702 of CP on the uplink system bandwidth 704.
Alternatively, 704 is an uplink sub-band. In this case, after
receiving the mixed time domain signal 701, there is a filter using
for filter out an UL sub-band. In the eNB, the filters for the
first path and the second path could be one multi-band filter or
multiple filters. It turns the signal into a first frequency domain
signal 705 based on the first uplink subcarrier spacing; repeats
(by block 713) discarding CP and transforming (e.g., by FFT 712)
mixed time domain until obtaining all of the first set 707 of
uplink resource elements. For example eNB gets frequency domain
signals 706 in multiple symbol durations; de-mapping (i.e. RE
de-mapping 713) the signals 708 on the first set 707 of uplink
resource elements, and decodes 714 the signals 708 on the first set
707 of uplink resource elements to obtain the first uplink channel
709 from the first UE. The method further comprising: filtering out
721 a second time domain signal 731 on an uplink sub-band 734
within the uplink system bandwidth 704 from the mixed time domain
signal 701, wherein the uplink sub-band 734 including all of the
second set 735 of uplink resource elements; discarding 722 a second
length 732 of CP (block 722 is also optional) and transforming
(e.g., by FFT 723) the second time domain signal 731 with the
second uplink symbol duration 733 after the second length 732 of CP
on the uplink sub-band 734 into a second frequency domain signal
736 based on the second uplink subcarrier spacing; repeating 725
discarding CPs 722 (block 722 is also optional) and transforming
723 the second time domain signals to get frequency domain signals
737 in multiple symbols until obtaining all of the second set 735
of uplink resource elements; de-mapping (i.e., RE de-mapping 725)
the signals 739 on the second set 735 of uplink resource elements
and decoding 726 the signals on the second set 735 of uplink
resource elements to obtain the second uplink channel 727 from the
second UE. In one example, the first length 702 of CP and second
length 732 of CP can be the same or different. eNB can use the same
hardware to implement the procedures from block 711 to 714 for the
first UE with first subcarrier spacing and then implement the
procedures from block 722 to 726 for the second UE with the second
subcarrier spacing. Comparing to supporting single subcarrier
spacing type of UEs, only one extra hardware component (i.e. a
filter) is needed. Alternatively, eNB can have multiple groups of
hardware to serve different UEs with different subcarrier spacing.
More hardware will increase the cost but save the processing time
(i.e., decoding latency).
[0070] FIG. 8 illustrates an example of symbol length and CP length
of different subcarrier spacing value according to the embodiment
of current invention. Because symbol length=1/subcarrier spacing,
the larger subcarrier spacing value has a shorter symbol duration,
and smaller subcarrier spacing results in a longer symbol duration.
For example, when subcarrier spacing=15 kHz, symbol duration= 1/15
kHz.apprxeq.66.7 .mu.s and when subcarrier spacing=3.75 kHz/1.25
kHz, symbol duration.apprxeq.266.7 .mu.s/800 .mu.s respectively. If
the same length of duration as one subframe is defined for
different subcarrier spacing values, the number of symbols in one
subframe is different for different subcarrier spacing values. For
example as FIG. 8 shown, there are fourteen symbols for subcarrier
spacing 800, three symbols for subcarrier spacing 810 and one
symbol for subcarrier spacing 820 within one subframe if the
subframe length is the same. Cyclic prefix (CP) is used for OFDM
system to avoid the effect of interference caused by multipath
propagation. Usually, the CP shall be longer than the maximum delay
spread. On the other hand, the long CP results in large overhead,
which will degrade spectral efficiency. In current LTE system, the
subcarrier spacing is 15 kHz for downlink and uplink control and
data channel, and each subframe is 1 ms with fourteen OFDM symbols
with one 5.1 .mu.s CP and the rest of 4.7 .mu.s CP length for
normal CP. For extend CP, there are 12 OFDM symbols with 16.7 .mu.s
CP length. If the subframe length is kept to be 1 ms, for 3.75 kHz
OFDM symbol, 3 OFDM symbol can be filled in with 66.7 .mu.s CP
length. Some examples for other subcarrier spacing values can be
found in Table 2. Observing Table 2, if subframe length is kept to
be the same, the CP length may become longer with a smaller
subcarrier spacing value. If the CP length is long enough, it may
cover the maximum Round-Trip Time (RTT) in a cell plus maximum
delay spread. For example, for the cell radius d=5 km/10 km/15 km,
roughly need a CP length of 38 .mu.s/71 .mu.s/103 .mu.s
respectively. As a result, with a longer CP, no timing advance is
needed. Some examples of the cell radius can be supported without
timing advance can be supported are also given in Table 2 for
different subcarrier spacing values with different CP lengths.
TABLE-US-00002 TABLE 2 Example of parameters for different
subcarrier spacing values Subcarrier spacing 15 kHz 5 kHz 3.75 kHz
2.5 kHz 1.25 kHz OFDM symbol length 66.7 .mu.s 200 .mu.s 266.7
.mu.s 400 .mu.s 800 .mu.s OFDM symbol number 14 4 3 2 1 CP length
5.1 .mu.s /4.7 .mu.s 50 .mu.s 66.7 .mu.s 100 .mu.s 200 .mu.s Cell
radius (without TA) NA 7.5 km 10.3 km 15.8 km 32.5 km
[0071] Reference signal (RS) may be needed for demodulation within
each resource block. For single carrier system (e.g., SC-FDMA for
LTE uplink), data and RS can be TDM. For example, in LTE uplink
system, two OFDM symbols are used as reference signal for PUSCH
demodulation within one subframe. For smaller subcarrier value, the
symbol length is longer, and this will result in larger overhead if
one symbol is taken as reference signal. Reducing time domain
reference signal density can reduce overhead. For example as shown
in FIG. 8, for subcarrier spacing 800, symbol 802 is used as
reference signal and in each subframe, there are two symbols used
as reference signal; for subcarrier spacing 810, symbol 812 is used
as reference signal and each subframe only has one symbol to be
used as reference signal; for subcarrier spacing 820, symbol 822 is
used as reference signal and every two subframes there is one
symbol to be used as reference signal. Noted that, the subcarrier
spacing values can be the different between the downlink subcarrier
spacing and the uplink subcarrier spacing. Alternatively, they can
also apply to the first uplink subcarrier spacing and the second
uplink subcarrier spacing.
[0072] In another embodiment, the definition of the slot or
subframe can be different for different subcarrier spacing values.
Resource block is defined for resource allocation, as N.sub.symb
consecutive SC-FDMA or OFDMA symbols in time domain and
N.sub.sc.sup.RB consecutive subcarriers in frequency domain. For
example in LTE system the resource block parameters is shown in
Table 3.
TABLE-US-00003 TABLE 3 Resource block parameters Configuration
N.sub.sc.sup.RB N.sub.symb Normal cyclic prefix 12 7 Extended
cyclic prefix 12 6
[0073] The transmitted signal in each slot is described by one or
several resource grids of N.sub.RB.sup.ULN.sub.sc.sup.RB
subcarriers and N.sub.symb.sup.UL SC-FDMA symbols. The resource
grid is illustrated in FIG. 9. The quantity N.sub.RB.sup.UL depends
on the uplink transmission bandwidth configured in the cell and
shall fulfil
N.sub.RB.sup.min,UL.ltoreq.N.sub.RB.sup.UL.ltoreq.N.sub.RB.sup.max,UL
where N.sub.RB.sup.min,UL=6 and N.sub.RB.sup.max,UL=110 are the
smallest and largest uplink bandwidths, respectively, supported by
the current version of the specification in LTE.
[0074] FIG. 10 illustrates examples of different definition of
resource block with different subcarrier spacing values according
to the embodiments of current invention. For subcarrier spacing
1021 in sub-band 1031, the subframe duration (i.e., the duration of
Physical Resource Block (PRB) 1001) is 1011. Similarly, for
subcarrier spacing 1022/1023 in sub-band 1032/1033, the subframe
duration is 1012/1013 respectively for PRB 1002/1003. This kind of
design is easy to support different requirement on latency, for
example some short latency traffic may use a short subframe
definition, which may need a large subcarrier spacing value and for
the traffic that is not sensitive to delay, a long subframe
definition can be introduced, which may go with a small subcarrier
spacing value. Furthermore, long subframe definition is also
beneficial for reference signal design if the density of reference
signal in time domain is low. For example, 3 ms can be defined as
one subframe for subcarrier spacing 1.25 kHz with one reference
signal every subframe. Noted that, the different subcarrier spacing
values can be the different between the downlink subcarrier spacing
and the uplink subcarrier spacing. Alternatively, they can also
apply to the first uplink subcarrier spacing and the second uplink
subcarrier spacing.
[0075] In the first embodiment, UE receives downlink channel and
transmits uplink channel using different subcarrier spacing (i.e.,
uplink subcarrier spacing and downlink subcarrier spacing is
different). In the other embodiment, eNB receives the first uplink
channel from the first UE with the first uplink subcarrier spacing
and the second uplink channel from the second UE with the second
uplink subcarrier spacing. The uplink subcarrier spacing in the
first embodiment or the second uplink subcarrier in the other
embodiment can be configured by eNB or pre-defined in the
specification. Alternatively, the first uplink subcarrier spacing
or the second uplink subcarrier spacing can be selected by UE. For
example, a subcarrier spacing values set can be known by the UE,
configured by eNB or written in the specification. UE can choose
one of the subcarrier spacing values within the pre-known
subcarrier spacing value set based on pre-known conditions. For
example, if the channel condition (e.g., path loss, coverage) is
within a range, then UE selects one of the subcarrier spacing
values. In another example, if UE uses different transmission
modes, then some corresponded subcarrier spacing values can be
used, for example, for contention based uplink transmission, one
subcarrier spacing value can be used and for scheduled uplink
transmission another subcarrier spacing value is selected. In
another example, if the TBS is in a range, UE uses subcarrier
spacing value a, otherwise used subcarrier spacing value b. In
another example, if the latency requirement is within a range, one
particular subcarrier spacing value is chosen. FIG. 11A illustrates
behaviors of UE and/or eNB to decide subcarrier spacing according
to the embodiments of current invention. In another example, if UE
belongs to a special UE category, one of the subcarrier spacing
values in the subcarrier spacing set is selected. The pre-known
conditions can be configured by RRC signaling or pre-defined in the
specification. In one embodiment, UE obtains configuration of
subcarrier spacing set in and corresponding sub-bands block 1101
and obtain the condition(s) for each subcarrier spacing values in
block 1102. Then UE selects one subcarrier spacing value within the
subcarrier spacing set based on the condition(s) in block 1103. UE
transmits uplink control or data channel based on the selected one
subcarrier spacing value in block 1104.
[0076] FIG. 11B illustrates behaviors of UE and/or eNB to decide
subcarrier spacing according to the embodiments of current
invention. The above condition(s) can be used by eNB and there is
no need to configure the above condition(s) to UE. That is, eNB
selects one subcarrier spacing value based on one or the
combination of the above conditions. In one embodiment, eNB
configures a subcarrier spacing set to UE in step 1111 and then eNB
selects one subcarrier spacing value within the subcarrier spacing
set based on the condition(s) and configures to UE in step 1113. UE
obtains the subcarrier spacing set from eNB in step 1112. Then UE
obtains the one subcarrier spacing value from eNB in step 1114. UE
transmits an uplink control or data channel on the configured one
subcarrier spacing value to the eNB in step 1115.
[0077] FIG. 11C illustrates behaviors of UE and/or eNB to decide
subcarrier spacing according to the embodiments of current
invention. In this embodiment, eNB selects one subcarrier spacing
value within the subcarrier spacing set based on the condition(s)
in step 1121 and directly configures to UE about the selected one
subcarrier spacing value in step 1122. And UE obtains the one
subcarrier spacing value and then transmits uplink control or data
channel on the configured one subcarrier spacing value to the eNB
in step 1123. This one subcarrier spacing value can be the uplink
subcarrier spacing or the second uplink carrier spacing. From UE
perspective, UE may only get one uplink subcarrier spacing, but
from eNB perspective, some UE may use the first uplink subcarrier
spacing and others may use the second subcarrier spacing. In the
following text, the mechanism for UE to obtain uplink subcarrier
spacing also applies to UE to obtain the first or the second uplink
subcarrier spacing.
[0078] If eNB decides the UEs who use the uplink subcarrier spacing
which is different from the downlink subcarrier spacing, or the UEs
who use the second uplink subcarrier spacing, eNB needs to get some
information of the UEs. FIG. 12A and FIG. 12B give two examples of
how eNB acquires information of UEs to decide subcarrier spacing
according to the embodiments of current invention. In the example
of FIG. 12A, UE sends a report to eNB in step 1201 and eNB
indicates the UE the subcarrier spacing configurations based on the
report from the UE in step 1202. The report may include at least
one of the condition(s) mentioned above such as channel condition,
UE category, transmission mode, etc. In another example of FIG.
12B, eNB obtains a message from core network in step 1214, the
message could be a NAS message, and based on the message from core
network, eNB indicates the subcarrier spacing to the UE in step
1215. Before that, UE may need to report UE identity (ID)
information to eNB in step 1212 so that eNB can ask for the message
from core network for the UE in step 1213. Alternative, core
network can acquire UE information directly from UE which is
transparent to eNB, and then core network send eNB the message in
step 1211, based on which eNB configure UE the subcarrier
spacing.
[0079] The uplink subcarrier spacing or the second uplink
subcarrier spacing can be pre-defined in order to reduce the
signaling overhead and complexity of eNB. In order to increase the
flexibility, in another embodiment, the uplink subcarrier spacing
is configured to the UE by higher layer signaling (e.g., in system
information or RRC signaling). Alternatively, UE can receive an
uplink assignment message to obtain the uplink subcarrier spacing
of the uplink resource elements or obtains the uplink subcarrier
spacing information with both higher layer singling and physical
layer signaling. Sometimes, UE needs to obtain the uplink
subcarrier spacing information with both higher layer singling and
physical layer signaling. For example, UE receives a uplink
subcarrier spacing value set in a higher layer signaling, e.g., in
SI, and the uplink subcarrier spacing is indicated by a physical
layer signaling, e.g. in DCI. Alternatively, the uplink subcarrier
spacing value set can be pre-defined and known to the UE. Another
example for UE to obtain the uplink subcarrier spacing is that UE
obtain the uplink subcarrier spacing information by obtaining the
radio resource region (e.g., a sub-band) for its uplink
transmission. UE obtains the uplink subcarrier spacing value set
and the radio resource region corresponding to each uplink
subcarrier spacing in the uplink subcarrier spacing set.
[0080] FIG. 13 illustrates an example of radio resource regions for
different subcarrier spacing values with some embodiments of
current invention. In one embodiment of the disclosure, a method
for a UE to transmit a waveform, the method comprising:
transmitting a uplink channel carrying uplink data channel or
control channel modulated with one subcarrier spacing value 1321,
e.g., 15 kHz, within a pre-known subcarrier spacing value set, such
as a subcarrier spacing value set of {3.75 kHz, 15 kHz, 30 kHz}.
The pre-known subcarrier spacing set can be configured by RRC
signaling (e.g., in system information), or alternatively, the
subcarrier spacing values are defined in the specification. In one
embodiment of the disclosure, each subcarrier spacing value in the
pre-known subcarrier spacing value set {3.75 kHz, 15 kHz, 30 kHz}
associate with one radio resource region, for example, sub-band
1301 is used for subcarrier spacing value 1321, i.e. 15 kHz,
sub-band 1302 is used for subcarrier spacing value 1322, i.e. 3.75
kHz and sub-band 1303 is used for subcarrier spacing value 1323,
i.e. 30 kHz. This corresponded radio resource region can also be
configured by RRC signaling (e.g., in system information), which
can be changed semi-statically. Alternatively, the corresponded
radio resource region can be defined in specification. UE transmit
uplink channel on an uplink assignment 1311 with one subcarrier
spacing value 15 kHz on sub-band 1301.
[0081] FIG. 14 illustrates an example of how UE obtaining the
uplink configurations including radio resource regions for
different subcarrier spacing values and uplink assignment with some
embodiments of current invention. In one embodiment, UE reads SI to
obtain subcarrier spacing value set and corresponding radio
resource regions for each subcarrier spacing value. For example, UE
learns that for sub-band 1401, 1402 and 1403, the corresponding
subcarrier spacing value is 1421, i.e. 15 kHz, 1422, i.e. 3.75 kHz
and 1423, i.e. 30 kHz respectively. UE receives RRC message, which
configures the one subcarrier for UE to transmit uplink. For
example, in FIG. 14, subcarrier spacing value 1422 equal to 3.75
kHz is configured to UE with the corresponding sub-band 1402. Since
the relationship between sub-band and subcarrier spacing value is
given in SI, either subcarrier spacing value or sub-band can be
configured in RRC message for the one subcarrier spacing value for
uplink transmission. eNB will give an assignment for uplink
transmission. In one example, the uplink assignment is indicated in
physical layer control information. In FIG. 14, the uplink
assignment 1411 is indicated in physical layer control information.
With all the above information, such as the one subcarrier spacing
value, sub-band information, uplink assignment, UE transmit uplink
waveform based on the above information.
[0082] In one embodiment, the sub-band can be pre-known to the UE
(e.g., through RRC message) when the UE get an uplink assignment,
the resource allocation in the physical layer control information
can only indicate the relative location within the sub-band. For
example, FIG. 15A and FIG. 15B illustrates examples of UL
assignment indication to the UE according to the embodiments of
current invention. UE can obtain system bandwidth 1500 and sub-band
bandwidth 1501, 1502 and 1503 for each sub-band 1501, 1502, and
1503 with subcarrier spacing 1521, 1522 and 1523 respectively in
broadcasting channel or UE-specific message. Furthermore, UE
receives a RRC message to configure UE to use sub-band 1502 for
subcarrier spacing 1522 and then UE may know the relative sub-band
location as well as the sub-band frequency. UE may receive an UL
assignment in physical layer control information (e.g., DCI). In
the control information, the UL assignment 1511 is given by one or
more physical resource block (PRB) index, wherein each of the PRB
index is defined within sub-band 1502 from PRB 1512 to PRB 1515.
For example, the uplink assignment is PRB 1514 in FIG. 15A.
[0083] In another embodiment of FIG. 15B, UE obtains system
bandwidth, subcarrier spacing values and corresponding sub-band by
UE-specific RRC message or broadcast or group-cast channel. The PRB
index is defined through the whole system bandwidth 1550. With the
information in UE-specific RRC message or broadcast or group-cast
channel, UE knows the sub-band for each subcarrier spacing value,
for example as FIG. 15B shown, sub-band 1551 (i.e., PRB 1561 to PRB
1563) is for subcarrier spacing 1521; sub-band 1552 (i.e., PRB 1564
to PRB 1566) is for subcarrier spacing 1522; and sub-band 1553
(i.e., PRB 1567 to PRB 1569) is for subcarrier spacing 1523. Before
uplink transmission, UE will receive an uplink assignment with PRB
index(es) for uplink transmission, for example from a DCI. In this
case, UE does not need to know which sub-band or subcarrier spacing
is used for uplink transmission, because it is indicated by PRB
index(es) in the uplink assignment. For example in FIG. 15B, UL
assignment 1511 is PRB 1565, which allocates in sub-band 1552 with
subcarrier spacing 1522.
[0084] FIG. 16 illustrates some examples of subcarrier spacing
configuration for different UEs according to some embodiments of
current invention. As mentioned previously, the subcarrier spacing
value and corresponded radio resource region can be UE-specific.
This means on the same radio resources, different UEs may transmit
uplink data or control channel with different subcarrier spacing
values. For example as FIG. 16 shown, UE #1 considers sub-band-0
1601, sub-band-1 1602 and sub-band-2 1603 used for
subcarrier-spacing-0 1612, subcarrier-spacing-1 1611 and
subcarrier-spacing-2 1613 respectively. UE #2 considers sub-band #0
1601 and sub-band #1 1602 all used for subcarrier-spacing-0 1612
and sub-band #2 1603 used for subcarrier-spacing-2 1613. However,
for UE #3, all the sub-band #0 1601, sub-band #1 1602 and sub-band
#2 1603 are used for subcarrier-spacing-1 1611. Also noted that,
for UE#3, there may not be sub-band concept but considering
subcarrier-spacing-1 1611 for the whole system bandwidth.
Alternatively, the corresponded radio resource region can be
cell-specific, which means all the UEs will transmitted uplink
waveform with the same subcarrier value in that region. For
example, all the UE considers sub-band 0/1/2 used subcarrier
spacing 0/1/2 respectively as UE#1. In another word, from eNB
perspective, the subcarrier spacing for the same sub-band can be
changed, e.g., subcarrier spacings can be different in different
radio frames or multiple subframes.
[0085] FIG. 17 illustrates some examples of resource allocations
for different subcarrier spacing with some embodiments of current
invention. In one embodiment, there is one type of UE, type I UE,
whose RF bandwidth 1730 with subcarrier spacing a, and another type
of UE, type II UE, whose RF bandwidth 1731 with subcarrier spacing
b in the system. Subcarrier spacing a can be same or different with
b. eNB can configure the regions (i.e. frequency location) to the
corresponding type of UE by RRC message, e.g., within system
information, and UE can obtain this information from eNB.
Alternatively, UE can know this information in specification. For
type I UE, it will know the whole RF bandwidth 1730 can be used
with subcarrier spacing a. eNB can make sure different types of UE
with different subcarrier spacing values and/or RF bandwidths are
scheduled to one the right region. For example, type I UE may
consider all RF bandwidth 1730 can be used for itself.
Alternatively, UE can know all the regions for all types of UE with
different RF bandwidths and/or different subcarrier spacing values
so that UE can learn which region is for itself. For example, type
I UE can know the region 1701, 1702, 1703, 1704, 1711, 1721, 1712
and 1722 are for other type of UEs.
[0086] For type II UE with RF bandwidth 1731, resource region for
RF bandwidth 1731 can be same (e.g., 1701-1704) or different (e.g.,
1711, 1721, 1712, 1722) in each subframe. Alternatively, the
resource region for RF bandwidth can be different (e.g., hopping to
a different sub-band) in another subframe bundling (i.e., several
continuous subframes). Also noticed that, for type II UE, the
definition of subframe can be different from other type of UEs. If
UE RF bandwidth is small, e.g., RF bandwidth 1731, it may require
tuning time to hop to a different frequency band. A discontinues
subframe set can be defined for one UE to support frequency
hopping, such as 1711 and 1712 belongs to one subframe set and 1721
and 1722 belongs to another subframe set, so that UE can have
enough time for frequency retuning. eNB can configure different
subframe set to different groups of UEs and no cell throughput loss
is expected if there are enough UEs in a cell. For example, eNB can
configure subframe set 1711 and 1712 to the UEs whose UE ID ends up
with odd and subframe set 1721 and 1722 to the UEs whose UE ID ends
up with even. The configuration with or without frequency hopping
can be supported in the same time by one eNB. UE can transmit or
retransmit one transport block in two or more subframes in the
frequency hopping subframe set, so that frequency diversity gain
can be obtained. In another embodiment, one transport block is
transmitted within one subframe.
[0087] In LTE system, uplink control channel, i.e. PUCCH, is
allocated at the edges of the uplink system bandwidth. For the UE
whose RF bandwidth is smaller than the system bandwidth may need a
new design for PUCCH. FIG. 18 illustrates some examples of control
channel design for narrow RF bandwidth UEs with some embodiments of
current invention. In one embodiment, the control channel allocated
at the edges 1805 of RF bandwidth 1810 or any pre-known frequency
location within RF bandwidth. This means control channel is FDM
with data channel within the RF bandwidth. In another embodiment,
the control channel allocated at any frequency location within the
system bandwidth 1800, such as 1806 and 1807, which may overlap
with other type UEs with the same RF bandwidth as system bandwidth
1800. In LTE system, PUCCH hops within two slots in one subframe.
However, narrow RF bandwidth type UE needs some time to retuning to
a different frequency; therefore in order to obtain similar
frequency diversity gain, one slot has to be used as a guard period
for retuning. For example, 1806 and 1807 are used for PUCCH for one
UE with RF bandwidth 1810, where 1806 and 1807 are in the first
slot of different subframes. Two UEs can be paired to occupy the
PUCCH region in two subframes without losing spectral efficiency.
For example, another UE can use the second slot after 1806 and
1807.
[0088] In another embodiment, some resource blocks can be used for
control channel and the other resource blocks can be used for data
channel, i.e., TDM between control channel and data channel
resource region not only from UE perspective but also from system
perspective. For example, resource block 1811 and 1812 can be used
for control channel transmission and resource block 1821 and 1822
can be used for data channel transmission. The resource blocks for
data channel or control channel are pre-known to UE. For example,
they can be configured by eNB or based on some pre-defined rules
such as subframe index or UE ID. The frequency location of resource
blocks for control channel or data channel can be the same (e.g.,
resource block 1801, resource block 1802) or different (e.g.,
resource block 1811 and resource block 1812) in different
subframes. Furthermore, the resource blocks for control channel or
data channel can be cell-specific or UE-specific. For example, all
the UE can use the resource block 1811 and 1812 for control channel
transmission which cannot be used for data transmission.
Considering UE may not transmit data channel and control channel in
the same time, two resource blocks can be defined within one
subframe for one UE. For example, resource block 1811 is configured
to transmit control channel and resource block 1801 is used to
transmit data channel. UE may also need retuning between different
subframes if different frequency location is used for the resource
block UE will use to transmit data or control channel.
[0089] New HARQ timing may need to be introduced for FDD system if
only some of subframes are allowed to transmit control channel.
FIG. 19 illustrates some examples of HARQ timing with some
embodiments of current invention. If only some of subframes or
resource blocks are allowed to transmit control information, such
as HARQ feedback, CSI feedback, scheduling request information, all
the HARQ feedback and/or other control information for one UE,
e.g., the HARQ feedback for downlink transmission 1911, 1912 and
1913 are multiplexed together in the same resource block or
subframe 1915, which is used for control channel transmission. In
another example, all HARQ feedbacks and/or other control
information for all the UEs, who are configured to use the same
resource block 1926, are transmitted on that resource block 1926.
For example, 1921 and 1924 is for the same UE and 1922 and 1923 is
for different UEs. The multiplexing method between the HARQ
feedbacks from the same or different UEs can be CDM, FDM and
TDM.
[0090] PRACH channel may also need a new design for the narrow band
UE or the UE using the second subcarrier spacing. As discussed
previously, the smaller subcarrier spacing can have a longer CP
without increase overhead. For example shown in Table 2, 3.75 kHz
subcarrier spacing can have 66.7 .mu.s CP length which can cover
10.3 km cell radius without timing advance. On the other hand, for
the UE in bad coverage, e.g., 15 dB coverage hole, dozens of
repetitions of PRACH are needed to bridge the coverage gap. PRACH
resources need to be reserved because eNB does not know when UE
will send a preamble sequence on the PRACH resources. Six PRBs
bandwidth are reserved for PRACH in current LTE system to provide a
1 .mu.s timing resolution due to current CP length is too small.
Different random access preamble formats are designed for different
cell radius with different length of CP. For example, format-2 with
CP length of -0.2 ms can cover about 29 km cell radius. Some
resources are configured to UE for PRACH. If UE in coverage
enhancement mode and normal coverage UE are served with in the same
cell, different resource needs to be reserved (FDM or TDM)
otherwise eNB cannot successful detect the UE in coverage
enhancement mode because the receiving signal is too wake and will
drown in signal from normal coverage UE even with different
sequence.
[0091] FIG. 20 illustrates some examples of PRACH configuration for
normal coverage UE and coverage enhancement mode UE with some
embodiments of current invention. PRACH resources are reserved for
normal UE can coverage enhancement (CE) mode UE and the resource
2001 for normal UE and 2002 for CE mode UE are FDM. Since
repetitions are needed to bridge the coverage gap, the PRACH
resource for CE mode UE covers several subframes, e.g., 32
subframes for resource 2002. For the scenario we discussed in this
disclosure, which different UEs may use different uplink subcarrier
spacing, or different UEs may have different RF bandwidth, it is
quite challenge to reuse the current PRACH design (with or without
repetition of PRACH). Some new design of PRACH is needed. One
solution for PRACH new design is reusing current PRACH channel
structure but boosting into a smaller bandwidth, e.g., 1 PRB. With
longer CP, boosting to a narrow bandwidth is possible because the
requirement of timing resolution is not that strict. Some error is
allowed which can be covered by longer CP.
[0092] Another solution is no need to have PRACH channel since TA
may be eliminated with long CP for uplink control and uplink data
channel. In another word, an uplink control channel or data channel
can be sent directly with a long CP. Preamble can be added before
the uplink control channel of data channel to simply the detection
of eNB. The functionality of PRACH can be replaced by PUCCH. Some
resources in PUCCH can be reserved for contention based uplink
transmission with 1-bit information. Random access response can be
transmitted after receiving the 1-bit information in the reserved
PUCCH. Similar message 3 and contention resolution as current LTE
system can be used to further identify UE and solves the contention
if different UEs choose the same resource in PUCCH. FIG. 21
illustrates some examples of PUCCH resource in time-frequency
domain and code domain according to embodiments of current
invention. Some symbols can be used for reference signals for
demodulation as (m01, m10), (m01, m15), (m03, m12), (m03, m12), and
(m03, m12). For 1-bit information for either PUCCH or PRACH can
choose one resource from a resource pool, such as (code 1, m01,
m10). Since different 1-bit information come from different UEs,
the reference signals also need to be orthogonal and associate one
resource within the resource pool. Some resources are reserved for
contention based 1-bit information to implement the functionalities
for PRACH, for example, PRB m01 can be reserved for the 1-bit
information. Since different UE may pass different channels,
different resource groups can be design for UE in different channel
conditions, e.g., PRB m01 is for good coverage UE and PRB m02 is
for bad coverage UE. Further, within PRB m01, some codes are
reserved for 1-bit contention information and the others are for
HARQ, CSI feedback or SR with configured or pre-known
resources.
[0093] FIG. 22 shows an exemplary flow chart for a UE to generate
the uplink channel occupies a set of uplink resource elements that
are different from the downlink resource elements in accordance
with embodiments of the current invention. At step 2201, the UE
receives a downlink channel from an eNB, wherein the downlink
channel occupies a set of downlink resource elements, each with a
frequency domain downlink subcarrier spacing and a time domain
downlink symbol duration. At step 2202, the UE generates an uplink
channel carrying uplink information bits, wherein the uplink
channel occupies a set of uplink resource elements, each with an
uplink frequency domain subcarrier spacing different from the
downlink subcarrier spacing and an uplink time domain symbol
duration different from the downlink symbol duration. At step 2203,
the UE transmits the uplink channel to the eNB.
[0094] FIG. 23 shows an exemplary flow chart for a base station to
handle the uplink channel occupies a set of uplink resource
elements that are different from the downlink resource elements in
accordance with embodiments of the current invention. At step 2301
the base station receives a first uplink channel carrying first
information bits from a first user equipment (UE) on a first set of
uplink resource elements, each has a first uplink frequency domain
subcarrier spacing and a first uplink time domain symbol duration.
At step 2302, the base station receives a second uplink channel
carrying second information bits from a second UE on a second set
of uplink resource elements, wherein each uplink resource element
in the second set has a second uplink frequency domain subcarrier
spacing different from the first uplink frequency domain subcarrier
spacing and a second uplink time domain symbol duration different
from the first uplink time domain symbol duration.
[0095] FIG. 24 shows an exemplary flow chart for a UE to perform
frequency hopping for narrowband configuration in accordance with
embodiments of the current invention. At step 2401, the UE
generates a communication channel in a wireless communication
network, wherein the communication channel is mapped to a sequence
of resource elements, each with a frequency sub-band of a system
frequency bandwidth and a time domain subframe number. At step
2402, the UE selects a first set of resource elements with a first
frequency band for consecutive number N of subframes for the
communication channel, wherein the first frequency band is a
sub-band of the system bandwidth. At step 2403, the UE hops to a
second set of resource elements with a second frequency band every
N consecutive number of subframes for the communication channel,
wherein the second frequency band is a sub-band of the system
bandwidth, and wherein the first and the second frequency band are
different. At step 2404, the UE sends or receives information bits
on the communication channel.
[0096] FIG. 25 shows an exemplary flow chart for a UE to perform
resource allocation for narrowband configuration in accordance with
embodiments of the current invention. At step 2501, the UE obtains
sub-band information and a resource index. At step 2502, the UE
generates a communication channel based on the obtained sub-band
information and the resource index. At step 2503, the UE sends or
receives information bits on the communication channel.
[0097] FIG. 26 shows an exemplary flow chart for a UE to perform
PUCCH selection for narrowband configuration in accordance with
embodiments of the current invention. At step 2601, the UE
determines an operating sub-band information in a wireless network,
wherein the operating sub-band is smaller than a system bandwidth,
and wherein the UE operates in the sub-band. At step 2602, the UE
selects one or more narrowband regions for a physical uplink
control channel (PUCCH) for the UE based on the determined
operating sub-band information, wherein the one or more selected
narrowband regions are at corresponding known locations of the
operating sub-band. At step 2603, the UE sends control information
to the wireless network on the PUCCH.
[0098] The previous description is provided to enable any person
skilled in the art to practice the various aspects described
herein. Various modifications to these aspects will be readily
apparent to those skilled in the art, and the generic principles
defined herein may be applied to other aspects. Thus, the claims
are not intended to be limited to the aspects shown herein, but is
to be accorded the full scope consistent with the language claims,
wherein reference to an element in the singular is not intended to
mean "one and only one" unless specifically so stated, but rather
"one or more." Unless specifically stated otherwise, the term
"some" refers to one or more. Combinations such as "at least one of
A, B, or C," "at least one of A, B, and C," and "A, B, C, or any
combination thereof" include any combination of A, B, and/or C, and
may include multiples of A, multiples of B, or multiples of C.
Specifically, combinations such as "at least one of A, B, or C,"
"at least one of A, B, and C," and "A, B, C, or any combination
thereof" may be A only, B only, C only, A and B, A and C, B and C,
or A and B and C, where any such combinations may contain one or
more member or members of A, B, or C. All structural and functional
equivalents to the elements of the various aspects described
throughout this disclosure that are known or later come to be known
to those of ordinary skill in the art are expressly incorporated
herein by reference and are intended to be encompassed by the
claims. Moreover, nothing disclosed herein is intended to be
dedicated to the public regardless of whether such disclosure is
explicitly recited in the claims. No claim element is to be
construed as a means plus function unless the element is expressly
recited using the phrase "means for."
[0099] The techniques described herein may be used for various
wireless communication systems such as CDMA, TDMA, FDMA, OFDMA,
SC-FDMA and other systems. The terms "system" and "network" are
often used interchangeably. A CDMA system may implement a radio
technology such as Universal Terrestrial Radio Access (UTRA),
cdma2000, etc. UTRA includes Time Division Synchronous Code
Division Multiple Access (TD-SCDMA), Wideband-CDMA (W-CDMA) and
other variants of CDMA. Further, cdma2000 covers IS-2000, IS-95 and
IS-856 standards. A TDMA system may implement a radio technology
such as Global System for Mobile Communications (GSM). An OFDMA
system may implement a radio technology such as Evolved UTRA
(E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE
802.16 (WiMAX), IEEE 802.20, Flash-OFDM.RTM., etc. UTRA and E-UTRA
are part of Universal Mobile Telecommunication System (UMTS). 3GPP
Long Term Evolution (LTE) is a release of UMTS that uses E-UTRA,
which employs OFDMA on the downlink and SC-FDMA on the uplink.
UTRA, E-UTRA, UMTS, TD-SCDMA, LTE and GSM are described in
documents from an organization named "3rd Generation Partnership
Project" (3GPP). Additionally, cdma2000 and UMB are described in
documents from an organization named "3rd Generation Partnership
Project 2" (3GPP2). Further, such wireless communication systems
may additionally include peer-to-peer (e.g., mobile-to-mobile) ad
hoc network systems often using unpaired unlicensed spectrums,
802.xx wireless LAN, BLUETOOTH and any other short- or long-range,
wireless communication techniques.
[0100] Although the embodiments and their advantages have been
described in detail, it should be understood that various changes,
substitutions, and alterations can be made herein without departing
from the spirit and scope of the embodiments as defined by the
appended claims. Moreover, the scope of the present application is
not intended to be limited to the particular embodiments of the
process, machine, manufacture, composition of matter, means,
methods, and steps described in the specification. As one of
ordinary skill in the art will readily appreciate from the
disclosure, processes, machines, manufacture, compositions of
matter, means, methods, or steps, presently existing or later to be
developed, that perform substantially the same function or achieve
substantially the same result as the corresponding embodiments
described herein may be utilized according to the disclosure.
Accordingly, the appended claims are intended to include within
their scope such processes, machines, manufacture, compositions of
matter, means, methods, or steps. In addition, each claim
constitutes a separate embodiment, and the combination of various
claims and embodiments are within the scope of the disclosure.
* * * * *