U.S. patent application number 13/438584 was filed with the patent office on 2012-09-20 for transmission of ack/nack bits and their embedding in the cqi reference signal.
This patent application is currently assigned to TEXAS INSTRUMENTS INCORPORATED. Invention is credited to Pierre Bertrand, Tarik Muharemovic, Zukang Shen.
Application Number | 20120236773 13/438584 |
Document ID | / |
Family ID | 40347018 |
Filed Date | 2012-09-20 |
United States Patent
Application |
20120236773 |
Kind Code |
A1 |
Shen; Zukang ; et
al. |
September 20, 2012 |
TRANSMISSION OF ACK/NACK BITS AND THEIR EMBEDDING IN THE CQI
REFERENCE SIGNAL
Abstract
A transmission within a wireless cellular network may include a
first and second type of information. A subframe includes a
plurality of symbols, at least one symbol is designated as a data
symbol and at least one symbol is designated as a reference signal
symbol that contains a pre-defined reference signal. The first type
of information is embedded in the data symbols. If the second type
of data is expected, then the second type of information is
embedded in at least one reference symbol by quadrature amplitude
modulating the pre-defined reference signal. The subframe is then
transmitted from one node in the network to a second node. If it is
determined that the second node is not expecting the second type of
information, then a discontinuous transmission (DTX) response is
embedded in the reference symbol instead of the second type of
information.
Inventors: |
Shen; Zukang; (Richardson,
TX) ; Muharemovic; Tarik; (Dallas, TX) ;
Bertrand; Pierre; (Antibes, FR) |
Assignee: |
TEXAS INSTRUMENTS
INCORPORATED
Dallas
TX
|
Family ID: |
40347018 |
Appl. No.: |
13/438584 |
Filed: |
April 3, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12183242 |
Jul 31, 2008 |
8149938 |
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13438584 |
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60954355 |
Aug 7, 2007 |
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60976720 |
Oct 1, 2007 |
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60978644 |
Oct 9, 2007 |
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61022878 |
Jan 23, 2008 |
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Current U.S.
Class: |
370/311 ;
370/328 |
Current CPC
Class: |
H04L 1/1671 20130101;
H04L 1/1692 20130101; H04L 5/0053 20130101; H04L 5/0007 20130101;
H04L 27/3483 20130101; H04L 27/2613 20130101; H04L 25/0226
20130101; H04L 27/206 20130101; H04L 1/0028 20130101 |
Class at
Publication: |
370/311 ;
370/328 |
International
Class: |
H04W 4/00 20090101
H04W004/00; H04W 52/02 20090101 H04W052/02 |
Claims
1-19. (canceled)
20. An apparatus for transmitting in a wireless cellular network,
comprising: generating circuitry for forming a plurality of data
symbols using a first type of information; generating circuitry for
forming at least one reference symbol using a pre-defined reference
signal; producing circuitry coupled to the generating circuitry and
operable to determine if a second type of information consisting of
an ACKNAK response is expected, and operable to produce a signal
comprising the plurality of data symbols and the at least one
reference symbol, wherein if the second type of information
consisting of an ACKNAK response is expected, then the second type
of information consisting of a 1-bit ACKNAK response is embedded in
at least one said reference symbol by: mapping the generated 1-bit
ACKNAK response into at least one symbol according to a
constellation mapping scheme comprising two constellation points,
wherein a 1-bit "ACK" response is mapped to a first constellation
point, wherein a 1-bit "NAK" response is mapped to a second
constellation point; and modulating the pre-defined reference
signal in the at least one reference symbol with the symbol mapped
from the 1-bit ACKNAK response; and transmitter circuitry coupled
to the producing circuitry operable to transmit the produced
signal.
21. The apparatus of claim 20, wherein if the second type of
information is not expected, then a discontinuous transmission
(DTX) symbol is embedded in the at least one said reference symbol
in place of the second type of information.
22. (canceled)
23. An apparatus for transmitting in a wireless cellular network,
comprising: generating circuitry for forming a plurality of data
symbols using a first type of information; generating circuitry for
forming at least one reference symbol using a pre-defined reference
signal; producing circuitry coupled to the generating circuitry and
operable to determine if a second type of information consisting of
an ACKNAK response is expected, and operable to produce a signal
comprising the plurality of data symbols and the at least one
reference symbol, wherein if the second type of information
consisting of an ACKNAK response is expected, then the second type
of information consisting of a 2-bit ACKNAK response is embedded in
at least one said reference symbol by: mapping the generated 2-bit
ACKNAK response into at least one symbol according to a
constellation mapping scheme comprising four constellation points,
wherein a 2-bit "ACK, ACK" response is mapped to a first
constellation point, wherein a 2-bit "ACK, NAK" response is mapped
to a second constellation point, wherein a 2-bit "NAK, ACK"
response is mapped to a third constellation point, wherein a 2-bit
"NAK, NAK" response is mapped to a fourth constellation point,
modulating the pre-defined reference signal in the at least one
reference symbol with the symbol mapped from the 2-bit ACKNAK
response, if the second type of information is not expected, then a
discontinuous transmission (DTX) symbol is embedded in the at least
one said reference symbol in place of the second type of
information; and transmitter circuitry coupled to the producing
circuitry operable to transmit the produced signal.
24. An apparatus for transmitting in a wireless cellular network,
comprising: generating circuitry for forming a plurality of data
symbols using a first type of information; generating circuitry for
forming at least one reference symbol using a pre-defined reference
signal; producing circuitry coupled to the generating circuitry and
operable to determine if a second type of information consisting of
an ACKNAK response is expected, and operable to produce a signal
comprising the plurality of data symbols and the at least one
reference symbol, wherein if the second type of information
consisting of an ACKNAK response is expected, then the second type
of information consisting of a 1-bit ACKNAK response is embedded in
at least one said reference symbol by: mapping the generated 1-bit
ACKNAK response into at least one symbol according to a
constellation mapping scheme comprising two constellation points,
wherein a 1-bit "ACK" response is mapped to a first constellation
point, wherein a 1-bit "NAK" response is mapped to a second
constellation point, wherein a discontinuous transmission "DTX"
response is mapped to same constellation point as the 1-bit "NAK"
response, and modulating the pre-defined reference signal in the at
least one reference symbol with the symbol formed by said mapping,
if the second type of information is not expected, then a
discontinuous transmission (DTX) symbol is embedded in the at least
one said reference symbol in place of the second type of
information; and transmitter circuitry coupled to the producing
circuitry operable to transmit the produced signal.
25. An apparatus for transmitting in a wireless cellular network,
comprising: generating circuitry for forming a plurality of data
symbols using a first type of information; generating circuitry for
forming at least one reference symbol using a pre-defined reference
signal; producing circuitry coupled to the generating circuitry and
operable to determine if a second type of information consisting of
an ACKNAK response is expected, and operable to produce a signal
comprising the plurality of data symbols and the at least one
reference symbol, wherein if the second type of information
consisting of an ACKNAK response is expected, then the second type
of information consisting of a 2-bit ACKNAK response is embedded in
at least one said reference symbol by: mapping the generated 2-bit
ACKNAK response into at least one symbol according to a
constellation mapping scheme comprising four constellation points,
wherein a 2-bit "ACK, ACK" response is mapped to a first
constellation point, wherein a 2-bit "ACK, NAK" response is mapped
to a second constellation point, wherein a 2-bit "NAK, ACK"
response is mapped to a third constellation point, wherein a 2-bit
"NAK, NAK" response is mapped to a fourth constellation point,
wherein a discontinuous transmission "DTX" response is mapped to
the same constellation point as the 2-bit "NAK, NAK" response, and
modulating the pre-defined reference signal in the at least one
reference symbol with the symbol formed by said mapping, if the
second type of information is not expected, then a discontinuous
transmission (DTX) symbol is embedded in the at least one said
reference symbol in place of the second type of information; and
transmitter circuitry coupled to the producing circuitry operable
to transmit the produced signal.
26. An apparatus for transmitting in a wireless cellular network,
comprising: generating circuitry for forming a plurality of data
symbols using a first type of information; generating circuitry for
forming at least one reference symbol using a pre-defined reference
signal; producing circuitry coupled to the generating circuitry and
operable to determine if a second type of information consisting of
an ACKNAK response is expected, and operable to produce a signal
comprising the plurality of data symbols and the at least one
reference symbol, wherein if the second type of information
consisting of an ACKNAK response is expected, then the second type
of information consisting of a 1-bit ACKNAK response is embedded in
at least one said reference symbol by: mapping the generated 1-bit
ACKNAK response into at least one symbol according to a
constellation mapping scheme comprising three constellation points,
wherein a 1-bit "ACK" response is mapped to a first constellation
point, wherein a 1-bit "NAK" response is mapped to a second
constellation point, wherein a discontinuous transmission "DTX"
response is mapped to a third constellation point, and modulating
the pre-defined reference signal in the at least one reference
symbol with the symbol formed by said mapping, if the second type
of information is not expected, then a discontinuous transmission
(DTX) symbol is embedded in the at least one said reference symbol
in place of the second type of information; and transmitter
circuitry coupled to the producing circuitry operable to transmit
the produced signal.
27. An apparatus for transmitting in a wireless cellular network,
comprising: generating circuitry for forming a plurality of data
symbols using a first type of information; generating circuitry for
forming at least one reference symbol using a pre-defined reference
signal; producing circuitry coupled to the generating circuitry and
operable to determine if a second type of information consisting of
an ACKNAK response is expected, and operable to produce a signal
comprising the plurality of data symbols and the at least one
reference symbol, wherein if the second type of information
consisting of an ACKNAK response is expected, then the second type
of information consisting of a 2-bit ACKNAK response is embedded in
at least one said reference symbol by: mapping the generated 2-bit
ACKNAK response into at least one symbol according to a
constellation mapping scheme comprising five constellation points,
wherein a 2-bit "ACK, ACK" response is mapped to a first
constellation point, wherein a 2-bit "ACK, NAK" response is mapped
to a second constellation point, wherein a 2-bit "NAK, ACK"
response is mapped to a third constellation point, wherein a 2-bit
"NAK, NAK" response is mapped to a fourth constellation point,
wherein a discontinuous transmission "DTX" response is mapped to a
fifth constellation point, and modulating the pre-defined reference
signal in the at least one reference symbol with the symbol formed
by said mapping, if the second type of information is not expected,
then a discontinuous transmission (DTX) symbol is embedded in the
at least one said reference symbol in place of the second type of
information; and transmitter circuitry coupled to the producing
circuitry operable to transmit the produced signal.
28. An apparatus for transmitting in a wireless cellular network,
comprising: generating circuitry for forming a plurality of data
symbols using a first type of information; generating circuitry for
forming at least one reference symbol using a pre-defined reference
signal; producing circuitry coupled to the generating circuitry and
operable to determine if a second type of information is expected,
and operable to produce a signal comprising the plurality of data
symbols and the at least one reference symbol, wherein if the
second type of information is expected, then the second type of
information is embedded in at least one said reference symbol by
modulating the pre-defined reference signal; transmitter circuitry
coupled to the producing circuitry operable to transmit a subframe
comprising formed data symbols and reference symbols to a receiver;
wherein each symbol confines to an orthogonal frequency division
multiplexing (OFDM) symbol; wherein transmitting the subframe lasts
for a duration which is an integral multiple of 0.5 ms slots;
wherein each 0.5 ms slot comprises five data symbols and two
reference symbols; wherein the first type of information is a
channel quality indicator (CQI) and the second type of information
is a 1-bit ACKNAK response; wherein forming a plurality of data
symbols using the first type of information comprises mapping the
CQI to produce five QPSK symbols per slot; and modulating each R-th
data symbol by producing a first sequence and multiplying the
entire first sequence with the R-th QPSK symbol mapped from the
first type of information; and wherein embedding the second type of
information in a second reference symbol of the two reference
symbols comprises: mapping the 1-bit ACKNAK response into at least
one BPSK symbol according to a BPSK constellation mapping scheme
comprising two constellation points, quadrature amplitude
modulating the second reference symbol by producing a second
sequence and multiplying the entire second sequence with one BPSK
symbol mapped from the second type of information, wherein a 1-bit
"ACK" response is mapped to a first BPSK constellation point, and
wherein a 1-bit "NAK" response is mapped to a second BPSK
constellation point.
29. An apparatus for transmitting in a wireless cellular network,
comprising: generating circuitry for forming a plurality of data
symbols using a first type of information; generating circuitry for
forming at least one reference symbol using a pre-defined reference
signal; producing circuitry coupled to the generating circuitry and
operable to determine if a second type of information is expected,
and operable to produce a signal comprising the plurality of data
symbols and the at least one reference symbol, wherein if the
second type of information is expected, then the second type of
information is embedded in at least one said reference symbol;
wherein each symbol confines to an orthogonal frequency division
multiplexing (OFDM) symbol; wherein transmitting the subframe lasts
for a duration which is an integral multiple of 0.5 ms slots;
wherein each 0.5 ms slot comprises five data symbols and two
reference symbols; wherein the first type of information is a
channel quality indicator (CQI) and the second type of information
is a 2-bit ACKNAK response; wherein forming a plurality of data
symbols using the first type of information comprises mapping the
CQI to produce five QPSK symbols per slot; modulating each R-th
data symbol by producing a first sequence and multiplying the
entire first sequence with the R-th QPSK symbol mapped from the
first type of information; and wherein embedding the second type of
information in a second reference symbol of the two reference
symbols comprises: mapping the 2-bit ACKNAK response into at least
one QPSK symbol according to a QPSK constellation mapping scheme
comprising four constellation points, quadrature amplitude
modulating the second reference symbol by producing a second
sequence and multiplying the entire second sequence with one QPSK
symbol mapped from the second type of information, wherein a 2-bit
"ACK, ACK" response is mapped to a first QPSK constellation point,
wherein a 2-bit "ACK, NAK" response is mapped to a second QPSK
constellation point, and wherein a 2-bit "NAK, ACK" response is
mapped to a third QPSK constellation point; and wherein a 2-bit
"NAK, NAK" response is mapped to a fourth QPSK constellation point.
transmitter circuitry coupled to the producing circuitry operable
to transmit the produced signal.
Description
CLAIM OF PRIORITY
[0001] This application for Patent claims priority to U.S.
application Ser. No. 12/183,242 entitled "Transmission of ACK/NACK
Bits and their Embedding in the CQI Reference Signal" filed Jul.
31, 2008, incorporated by reference herein. This application for
Patent claims priority to U.S. Provisional Application No.
60/954,355 entitled "Embedding ACK/NAK Bits in CQI Reference
Signals" filed Aug. 7, 2007, incorporated by reference herein. This
application for Patent claims priority to U.S. Provisional
Application No. 60/976,720 entitled "Embedding ACK/NAK in CQI
Reference Signal with DTX Detection" filed Oct. 1, 2007,
incorporated by reference herein. This application for Patent
claims priority to U.S. Provisional Application No. 60/978,644
entitled "Embedding ACK/NAK in CQI Reference Signal with DTX
Detection" filed Oct. 7, 2007, incorporated by reference herein.
This application for Patent also claims priority to U.S.
Provisional Application No. 61/022,878 entitled "Embedding ACK/NAK
in CQI Reference Signal with DTX Detection" filed Jan. 23, 2008,
incorporated by reference herein.
FIELD OF THE INVENTION
[0002] This invention generally relates to wireless cellular
communication, and in particular to encoding a reference signal in
orthogonal frequency division multiple access (OFDMA), DFT-spread
OFDMA, and single carrier frequency division multiple access
(SC-FDMA) systems.
BACKGROUND OF THE INVENTION
[0003] Wireless cellular communication networks incorporate a
number of mobile UEs and a number of NodeBs. A NodeB is generally a
fixed station, and may also be called a base transceiver system
(BTS), an access point (AP), a base station (BS), or some other
equivalent terminology. As improvements of networks are made, the
NodeB functionality evolves, so a NodeB is sometimes also referred
to as an evolved NodeB (eNB). In general, NodeB hardware, when
deployed, is fixed and stationary, while the UE hardware is
portable.
[0004] In contrast to NodeB, the mobile UE can comprise portable
hardware. User equipment (UE), also commonly referred to as a
terminal or a mobile station, may be fixed or mobile device and may
be a wireless device, a cellular phone, a personal digital
assistant (PDA), a wireless modem card, and so on. Uplink
communication (UL) refers to a communication from the mobile UE to
the NodeB, whereas downlink (DL) refers to communication from the
NodeB to the mobile UE. Each NodeB contains radio frequency
transmitter(s) and the receiver(s) used to communicate directly
with the mobiles, which move freely around it. Similarly, each
mobile UE contains radio frequency transmitter(s) and the
receiver(s) used to communicate directly with the NodeB. In
cellular networks, the mobiles cannot communicate directly with
each other but have to communicate with the NodeB.
[0005] Control information bits are transmitted, for example, in
the uplink (UL), for several purposes. For instance, Downlink
Hybrid Automatic Repeat ReQuest (HARQ) requires at least one bit of
ACK/NACK transmitted in the uplink, indicating successful or failed
circular redundancy check(s) (CRC). Moreover, a one bit scheduling
request indicator (SRI) is transmitted in uplink, when UE has new
data arrival for transmission in uplink. Furthermore, an indicator
of downlink channel quality (CQI) needs to be transmitted in the
uplink to support mobile UE scheduling in the downlink. While CQI
may be transmitted based on a periodic or triggered mechanism, the
ACK/NACK needs to be transmitted in a timely manner to support the
HARQ operation. Note that ACK/NACK is sometimes denoted as ACKNAK
or just simply ACK, or any other equivalent term. As seen from this
example, some elements of the control information should be
provided additional protection, when compared with other
information. For instance, the ACK/NACK information is typically
required to be highly reliable in order to support an appropriate
and accurate HARQ operation. This uplink control information is
typically transmitted using the physical uplink control channel
(PUCCH), as defined by the 3GPP working groups (WG), for evolved
universal terrestrial radio access (EUTRA). The EUTRA is sometimes
also referred to as 3GPP long-term evolution (3GPP LTE). The
structure of the PUCCH is designed to provide sufficiently high
transmission reliability.
[0006] In addition to PUCCH, the EUTRA standard also defines a
physical uplink shared channel (PUSCH), intended for transmission
of uplink user data. The Physical Uplink Shared Channel (PUSCH) can
be dynamically scheduled. This means that time-frequency resources
of PUSCH are re-allocated every sub-frame. This (re)allocation is
communicated to the mobile UE using the Physical Downlink Control
Channel (PDCCH). Alternatively, resources of the PUSCH can be
allocated semi-statically, via the mechanism of persistent
scheduling. Thus, any given time-frequency PUSCH resource can
possibly be used by any mobile UE, depending on the scheduler
allocation. Physical Uplink Control Channel (PUCCH) is different
than the PUSCH, and the PUCCH is used for transmission of uplink
control information (UCI). Frequency resources which are allocated
for PUCCH are found at the two extreme edges of the uplink
frequency spectrum. In contrast, frequency resources which are used
for PUSCH are in between. Since PUSCH is designed for transmission
of user data, re-transmissions are possible, and PUSCH is expected
to be generally scheduled with less stand-alone sub-frame
reliability than PUCCH. The general operations of the physical
channels are described in the EUTRA specifications, for example:
"3.sup.rd Generation Partnership Project; Technical Specification
Group Radio Access Network; Evolved Universal Terrestrial Radio
Access (E-UTRA); Physical Channels and Modulation (Release 8)."
[0007] A reference signal (RS) is a pre-defined signal, pre-known
to both transmitter and receiver. The RS can generally be thought
of as deterministic from the perspective of both transmitter and
receiver. The RS is typically transmitted in order for the receiver
to estimate the signal propagation medium. This process is also
known as "channel estimation." Thus, an RS can be transmitted to
facilitate channel estimation. Upon deriving channel estimates,
these estimates are used for demodulation of transmitted
information. This type of RS is sometimes referred to as
De-Modulation RS or DM RS. Note that RS can also be transmitted for
other purposes, such as channel sounding (SRS), synchronization, or
any other purpose. Also note that Reference Signal (RS) can be
sometimes called the pilot signal, or the training signal, or any
other equivalent term.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Particular embodiments in accordance with the invention will
now be described, by way of example only, and with reference to the
accompanying drawings:
[0009] FIG. 1 is a pictorial of an illustrative telecommunications
network that employs an embodiment of RS symbols modulated to
convey information;
[0010] FIG. 2 is a diagram of one embodiment of embedding a first
type of information in the data symbols and embedding a second type
of information in the RS symbols by quadrature amplitude
modulation;
[0011] FIG. 3 is a diagram of another embodiment of embedding a
second type of information in one RS symbol by quadrature amplitude
modulation and inserting a pre-defined signal in another RS
symbol;
[0012] FIGS. 4-6 are diagrams illustrating various embodiments with
a process of determining whether a second type of information
exists prior to the generation of second type of information;
[0013] FIG. 7 is a diagram where the first type of information is a
channel quality indicator (CQI) and the second type of information
is an ACKNAK response;
[0014] FIG. 8 shows an OFDM modulated first and second type of
information;
[0015] FIG. 9 is a detailed diagram of FIG. 8;
[0016] FIG. 10 is a block diagram of OFDMA modulation;
[0017] FIG. 11 is a block diagram of SC-OFDMA modulation;
[0018] FIG. 12 is a diagram illustrating two slots of a subframe,
where each slot uses the orthogonal structure of FIG. 9;
[0019] FIG. 13 is an illustration of a mapping of one ACKNAK bit to
a BPSK constellation;
[0020] FIG. 14 is an illustration of a mapping of two ACKNAK bits
to a QPSK constellation;
[0021] FIG. 15 is an illustration of another mapping of one ACKNAK
bit to a BPSK constellation;
[0022] FIG. 16 is an illustration of another mapping of two ACKNAK
bits to a QPSK constellation;
[0023] FIG. 17 is an illustration of a mapping of two ACK/NAK Bits
and a DTX indicator to a 5PSK constellation;
[0024] FIG. 18 an illustration of a mapping of one ACK/NAK Bit and
a DTX indicator to a 3PSK constellation;
[0025] FIG. 19 is a block diagram of a Node B and a User Equipment
for use in the network system of FIG. 1; and
[0026] FIG. 20 is a block diagram of a cellular phone for use in
the network of FIG. 1.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0027] FIG. 1 shows an exemplary wireless telecommunications
network 100. The illustrative telecommunications network includes
representative base stations 101, 102, and 103; however, a
telecommunications network necessarily includes many more base
stations. Each of base stations 101, 102, and 103 are operable over
corresponding coverage areas 104, 105, and 106. Each base station's
coverage area is further divided into cells. In the illustrated
network, each base station's coverage area is divided into three
cells. Handset or other UE 109 is shown in Cell A 108, which is
within coverage area 104 of base station 101. Base station 101 is
transmitting to and receiving transmissions from UE 109 via
downlink 110 and uplink 111. As UE 109 moves out of Cell A 108, and
into Cell B 107, UE 109 may be handed over to base station 102.
Because UE 109 is synchronized with base station 101, UE 109 must
employ non-synchronized random access to initiate handover to base
station 102.
[0028] A UE in a cell may be stationary such as within a home or
office, or may be moving while a user is walking or riding in a
vehicle. UE 109 moves within cell 108 with a velocity 112 relative
to base station 102.
[0029] Channel quality indicator (CQI) needs to be fed back in
uplink (UL) to support dynamic scheduling and
multiple-input-multiple-output (MIMO) transmission on downlink
(DL). In 3GPP EUTRA, if a UE (user equipment) has no uplink data
transmission, its CQI is transmitted on a dedicated UL control
channel (i.e. PUCCH). Given that the ACK/NACK needs to be
transmitted in a timely manner to support the HARQ operation, in
one embodiment of the invention ACKNK may be embedded in one or
more of the RS symbols of a CQI transmission.
[0030] FIG. 2 is a diagram of one embodiment of embedding a first
type of information 204 in the data symbols 202 and embedding a
second type of information 206 in the RS symbols 203a, 203b. A
transmission signal 201 comprises at least one data symbol 202 and
at least one RS symbol 203. An exemplary transmission signal
comprising five data symbols and two RS symbols is shown in FIG. 2.
The first type of information is transmitted in at least one data
symbol, and the second type of information is transmitted in at
least one RS symbol. The second type of information is firstly
mapped 208 to a constellation point according to a mapping scheme,
e.g. a quadrature amplitude modulation (QAM) mapping scheme. The
produced constellation point mapped from the second type of
information is transmitted in at least one RS symbol by
modulating/multiplying the RS symbol with the produced
constellation point. It is not precluded that the second type of
information is mapped to a multiple of constellation points, each
of which is transmitted in one RS symbol by modulation/multiplying
the reference signal with the corresponding constellation
point.
[0031] FIG. 3 is a diagram of another embodiment of the invention.
An exemplary transmission signal 301 comprises five data symbol and
two RS symbols. The first type of information is transmitted in the
data symbols and the second type of information is transmitted in
one RS symbol, e.g. the second RS symbol 302b in FIG. 3. The second
type of information is firstly mapped to a constellation point
according to a mapping scheme, e.g. a quadrature amplitude
modulation (QAM) mapping scheme. The produced constellation point
mapped from the second type of information is transmitted in the
second RS symbol by modulating/multiplying the reference signal
with the produced constellation point. A pre-defined reference
signal 310 is inserted in the first RS symbol 303a, which can be
used to perform channel estimation for coherent demodulation of the
first and second type of information. It is not precluded that a
transmission signal can comprise more than two RS symbols, where
the second type of information is transmitted in a subset of the RS
symbols and pre-defined reference signals are transmitted in the
rest RS symbols. The pre-defined reference signal transmitted in
each RS symbol can be the same. Alternatively, the pre-defined
reference signals can be different in different RS symbols,
provided these pre-defined reference signals are known to both the
transmitter and the receiver.
[0032] FIGS. 4-6 are diagrams illustrating various embodiments of
the invention with a process of determining 412 whether a second
type of information exists prior to the generation of second type
of information. FIG. 4 shows an embodiment that if the second type
of information is expected 414, then generate 416 the second type
of information and transmit the generated second type of
information in at least one RS symbols by mapping and modulation
408 of one or more reference signals of transmission signal 401, as
described in more detail with respect to FIG. 2.
[0033] FIG. 5 shows an embodiment in which if the second type of
information exists, then generate the second type of information,
transmit the second type of information in one of the RS symbols
503b, and insert a pre-defined reference signal 510 in the other RS
symbol 503a of transmission signal 501, as was described in more
detail with respect to FIG. 3.
[0034] FIG. 6 shows an embodiment in which a determination 612 is
made that the second type of information does not exist or is not
expected 618. In this case, a pre-defined reference signal 620 is
inserted in all RS symbols of transmission signal 601. The
pre-defined reference signal transmitted in each RS symbol can be
the same. Alternatively, the pre-defined reference signals can be
different in different RS symbols, provided these pre-defined
reference signals are known to both the transmitter and the
receiver.
[0035] FIG. 7 is a diagram where the first type of information is a
channel quality indicator (CQI) 704 and the second type of
information is an ACKNAK response 706. An exemplary transmission
signal 701 in FIG. 7 comprises five data symbols and two RS symbols
703a, 703b. The CQI is firstly mapped 705 to a number of
constellation points, e.g. according to a quadrature amplitude
modulation (QAM) mapping scheme. The constellation points mapped
from the CQI are then transmitted on the data symbols, by
modulating/multiplying each data symbol with a corresponding
constellation point. CQI includes, but not limited to Rank
Indicator (RI), Precoding Matrix Indicator (PMI), Modulation and
Coding Scheme (MCS), or combinations thereof.
[0036] The ACKNAK response 706 is firstly mapped 708 to a
constellation point, e.g. according to a quadrature amplitude
modulation mapping scheme. The constellation point mapped from the
ACKNAK response is transmitted in the second RS symbol 703b by
modulating/multiplying the reference signal with the constellation
point. A pre-defined reference signal 710 is transmitted in the
first RS symbol 703a. It is not precluded that a transmission
signal can comprise more than two RS symbols, where the ACKNAK
response is transmitted in a subset of the RS symbols and
pre-defined reference signals are transmitted in the rest RS
symbols. The pre-defined reference signal transmitted in each RS
symbol can be the same. Alternatively, the pre-defined reference
signals can be different in different RS symbols, provided these
pre-defined reference signals are known to both the transmitter and
the receiver.
[0037] In some embodiments of the invention, said ACKNAK
information element is produced by receiving a data packet,
followed by performing error detection or error checking on the
received data packet. In some embodiments of the invention, the
error checking is achieved using a circular redundancy check (CRC),
where the CRC can "pass" or "fail." If a CRC "fails" an error
detection is declared, whereas if the CRC "passes" a transmission
success is declared. If an error is detected, a NAK is transmitted
as a specific realization of ACKNAK information element, whereas if
no error is detected, an ACK is transmitted as another specific
realization of the ACKNAK information element.
[0038] FIG. 8 illustrates an embodiment of the invention where the
first and second types of information are OFDM modulated. An
exemplary transmission signal 801 comprises five OFDM data symbols
and two OFDM RS symbols 803a, 803b. One embodiment is that the
first type of information is a CQI 804 and the second type of
information is an ACKNAK response 806. The CQI is firstly mapped
805 to a multiple of constellation points, e.g. according to a
quadrature amplitude modulation mapping scheme. Each constellation
point mapped from the CQI is used to form an OFDM signal 830, which
is transmitted in a corresponding data symbol. CQI includes, but
not limited to Rank Indicator (RI), Precoding Matrix Indicator
(PMI), Modulation and Coding Scheme (MCS), or combinations
thereof.
[0039] The ACK/NAK response is firstly mapped 808 to a
constellation point, e.g. according to a quadrature amplitude
modulation mapping scheme. The constellation point mapped from the
ACKNAK response is used to form an OFDM signal 832, which is
transmitted in the second RS symbol 803b. A pre-defined signal 810
is used to form a pre-defined OFDM reference signal 831, which is
transmitted in the first RS symbol 803a. It is not precluded that a
transmission signal can comprise more than two OFDM RS symbols,
where the ACKNAK response is transmitted in a subset of the RS
symbols and pre-defined OFDM reference signals are transmitted in
the rest RS symbols. The pre-defined OFDM reference signal
transmitted in each RS symbol can be the same. Alternatively, the
pre-defined OFDM reference signals can be different in different RS
symbols, provided these pre-defined OFDM reference signals are
known to both the transmitter and the receiver.
[0040] FIG. 9 is a more detailed diagram of FIG. 8. An exemplary
transmission signal 901 comprises five OFDM symbols and two OFDM RS
symbols 903a, 903b. The CQI 904 is mapped 905 to five QAM
constellation points [d.sub.1(0), d.sub.1(1), d.sub.1(2),
d.sub.1(3), d.sub.1(4)]. A first sequence 932 is generated and used
to form an OFDM signal 930. The transmission signal in the R-th
data OFDM symbol, indicated generally as 902, is the product of the
OFDM modulated first sequence 930 and the R-th constellation point
mapped from CQI, i.e. d.sub.1(R-1). The multiplication, indicated
generally as 940, of the OFDM modulated first sequence and the R-th
constellation point d.sub.1(R-1) is performed such that the entire
OFDM modulated first sequence is multiplied with the R-th
constellation point d.sub.1(R-1). Note that the first sequence 932
in different data symbols can be different, provided these first
sequences are known to both the transmitter and the receiver.
[0041] The ACK/NAK response 906 is mapped 908 to a QAM
constellation point d.sub.2(0). A second sequence is generated and
used to form an OFDM signal. The transmission signal in the second
RS symbol 903b is the product of the OFDM modulated second sequence
934b and the constellation point mapped from the ACKNAK response,
i.e. d.sub.2(0). The multiplication 942 of the OFDM modulated
second sequence and the ACKNAK constellation d.sub.2(0) is
performed such that the entire OFDM modulated second sequence is
multiplied with d.sub.2(0). A second sequence 934a is generated and
used to form a pre-defined OFDM signal, which is transmitted in the
first RS symbol 903a. Note that the second sequence in different RS
symbols can be different, provided these second sequences are known
to both the transmitter and the receiver.
[0042] In one embodiment of the invention, the first type of
information is a channel quality indicator and the second type of
information is a 1-bit ACK/NAK response. The CQI is mapped to a
multiple of QAM constellation points, each of which is transmitted
in one data OFDM symbol. The 1-bit ACKNAK response is mapped
according to a binary phase shift keyed (BPSK) constellation
mapping scheme. The generated ACKNAK BPSK constellation is
transmitted in one of the RS symbols, as described in more detail
with respect to FIG. 9. FIG. 13 is an illustration of a mapping of
1-bit ACKNAK to a rotated BPSK constellation having two
constellation points 1300, 1301. FIG. 15 is an illustration of
another mapping of 1-bit ACKNAK to a BPSK constellation. Other
rotations may be used in other embodiments.
[0043] In another embodiment of the invention, the first type of
information is a CQI and the second type of information is a 2-bit
ACK/NAK response. The CQI is mapped to a multiple of QAM
constellation points, each of which is transmitted in one data OFDM
symbol. The 2-bit ACKNAK response is mapped according to a
quadrature phase shift keyed (QPSK) constellation mapping scheme.
The generated ACKNAK QPSK constellation is transmitted in one of
the RS symbols, as described in more detail with respect to FIG. 9.
FIG. 14 is an illustration of a mapping of 2-bit ACKNAK to a
rotated QPSK constellation having four constellation points
1400-1403. FIG. 16 is an illustration of another mapping of 2-bit
ACKNAK to a QPSK constellation. Other embodiments may use a four
point constellation with different rotation or configuration.
[0044] FIG. 10 illustrates a block diagram of modulation of an
orthogonal frequency-division multiplexing (OFDM) system. Block
[c.sub.k(0) . . . c.sub.k(L-1)] 1050 denotes the user signal of
user k. This user signal includes but is not limited to reference
signal, data signal, control signal, and random access pre-amble.
Modulation block 1052 includes tone map 1053, inverse Fast Fourier
transform (IFFT) block 154, and parallel-to-serial (P/S) converter
1055. Tone map 1053 maps the user signal onto L sub-carriers in the
frequency domain. IFFT block 1054 converts these signals from
frequency domain to temporal domain. Copies of modulation block
1052 in FIG. 10 can service a plurality of UEs. The plural signals
from the plural UEs are transmitted on different sub-carriers at
the same time period as designated by a UE specific tone map 1053.
Such a system is sometimes called orthogonal frequency division
multiple access (OFDMA) system. These plural user signals and tone
maps are omitted for clarity. P/S converter 1055 converts these
parallel signals into a single serial signal 1060. A cyclic prefix
(CP) 1061 is inserted by repeating a portion of the serial
signal.
[0045] FIG. 11 illustrates an alternate modulation block 1152 to
that of FIG. 10. Block [c.sub.k(0) . . . c.sub.k(L-1)] 1150 denotes
the user signal of user k. This user signal includes but not
limited to reference signal, data signal and control signal.
Modulation block 1152 includes discrete Fourier Transform (DFT)
block 1156, tone map 1153, inverse Fast Fourier transform (IFFT)
block 1154 and parallel-to-serial (P/S) converter 1155. In FIG. 11,
the user signal is first processed by DFT block 1156. Tone map 1153
maps the user signal onto L sub-carriers as described above in
conjunction with FIG. 10. IFFT block 1154 converts these signals
from frequency domain to temporal domain. Copies of modulation
block 1152 in FIG. 11 can service a plurality of UEs. The plural
signals from the plural UEs are transmitted on different
sub-carriers at the same time period as designated by a UE specific
tone map 1153. Such a system is sometimes called single carrier
orthogonal frequency division multiple access (SC-OFDMA) system.
These plural user signals, DFT blocks and tone maps are omitted for
clarity. P/S converter 1156 converts these parallel signals into a
single serial signal 1160. A cyclic prefix (CP) 1161 is inserted by
repeating a portion of the serial signal.
[0046] One embodiment of the user signal [c.sub.k(0) . . .
c.sub.k(L-1)] 1050, 1150 in FIG. 10 or FIG. 11, respectively, is
first sequence 932 or second sequence 934 in FIG. 9. One embodiment
of [c.sub.k(0) . . . c.sub.k(L-1)] is a cyclically shifted or phase
ramped CAZAC-like sequence. In this disclosure, a CAZAC-like
sequence generally refers to any sequence that has the property of
constant amplitude zero auto correlation. Examples of CAZAC-like
sequences includes but not limited to, Chu Sequences, Frank-Zadoff
Sequences, Zadoff-Chu (ZC) Sequences, Generalized Chirp-Like (GCL)
Sequences, or any computer generated CAZAC sequences. One example
of a CAZAC-like sequence r.sub.u,v(n) is given by
r.sub.u,v(n)=e.sup.j.phi.(n).pi./4,
0.ltoreq.n.ltoreq.M.sub.sc.sup.RS-1
where M.sub.sc.sup.RS=12 and .phi.(n) is defined in Table 1.
[0047] In this disclosure, the cyclically shifted or phase ramped
CAZAC-like sequence is sometimes denoted as cyclic shifted base
sequence, cyclic shifted root sequence, phase ramped base sequence,
phase ramped root sequence, or any other equivalent term.
TABLE-US-00001 TABLE 1 Definition of .phi. (n) u .phi. (0), . . . ,
.phi. (11) 0 -1 1 3 -3 3 3 1 1 3 1 -3 3 1 1 1 3 3 3 -1 1 -3 -3 1 -3
3 2 1 1 -3 -3 -3 -1 -3 -3 1 -3 1 -1 3 -1 1 1 1 1 -1 -3 -3 1 -3 3 -1
4 -1 3 1 -1 1 -1 -3 -1 1 -1 1 3 5 1 -3 3 -1 -1 1 1 -1 -1 3 -3 1 6
-1 3 -3 -3 -3 3 1 -1 3 3 -3 1 7 -3 -1 -1 -1 1 -3 3 -1 1 -3 3 1 8 1
-3 3 1 -1 -1 -1 1 1 3 -1 1 9 1 -3 -1 3 3 -1 -3 1 1 1 1 1 10 -1 3 -1
1 1 -3 -3 -1 -3 -3 3 -1 11 3 1 -1 -1 3 3 -3 1 3 1 3 3 12 1 -3 1 1
-3 1 1 1 -3 -3 -3 1 13 3 3 -3 3 -3 1 1 3 -1 -3 3 3 14 -3 1 -1 -3 -1
3 1 3 3 3 -1 1 15 3 -1 1 -3 -1 -1 1 1 3 1 -1 -3 16 1 3 1 -1 1 3 3 3
-1 -1 3 -1 17 -3 1 1 3 -3 3 -3 -3 3 1 3 -1 18 -3 3 1 1 -3 1 -3 -3
-1 -1 1 -3 19 -1 3 1 3 1 -1 -1 3 -3 -1 -3 -1 20 -1 -3 1 1 1 1 3 1
-1 1 -3 -1 21 -1 3 -1 1 -3 -3 -3 -3 -3 1 -1 -3 22 1 1 -3 -3 -3 -3
-1 3 -3 1 -3 3 23 1 1 -1 -3 -1 -3 1 -1 1 3 -1 1 24 1 1 3 1 3 3 -1 1
-1 -3 -3 1 25 1 -3 3 3 1 3 3 1 -3 -1 -1 3 26 1 3 -3 -3 3 -3 1 -1 -1
3 -1 -3 27 -3 -1 -3 -1 -3 3 1 -1 1 3 -3 -3 28 -1 3 -3 3 -1 3 3 -3 3
3 -1 -1 29 3 -3 -3 -1 -1 -3 -1 3 -3 3 1 -1
[0048] The first sequence in different data symbols in FIG. 9 can
be different. In one embodiment, the first sequences in different
data symbols are cyclic shifted or phase ramped ZACAC-like
sequences of a base sequence, with different amounts of cyclic
shifts or phase ramps on different data symbols.
[0049] The second sequence in different RS symbols in FIG. 9 can be
different. In one embodiment, the second sequences in different RS
symbols are cyclic shifted or phase ramped ZACAC-like sequences of
a base sequence, with different amounts of cyclic shifts or phase
ramps on different RS symbols.
[0050] In 3GPP EUTRA UL, single carrier OFDMA (SC-OFDMA) is adopted
as the transmission scheme due to its low peak-to-average ratio
(PAR) or cubic metric (CM) property. In the context of CQI
transmission on PUCCH, SC-OFDMA essentially means a UE can only
transmit on one cyclic shift at each OFDM symbol to keep the PAR/CM
low. For example, in FIG. 9, each UE is assigned with one usable
cyclic shift per OFDM symbol.
[0051] FIG. 12 is a diagram illustrating two slots 1200, 1201 of a
sub-frame of a transmission signal, where each slot uses the
orthogonal structure of FIG. 9. The transmission signal in the two
slots may occur at different bandwidth, to exploit frequency
diversity. In this embodiment, the first type of information is a
CQI and the second type of information is an ACKNAK response. In
this embodiment, one slot of a transmission of duration 0.5 ms is
illustrated in which there are seven OFDM symbols per slot. Each
symbol is generated using a cyclic shifted CAZAC-like sequence. The
2.sup.nd and 6th OFDM symbols of each slot are used as reference
signals 1202a, 1202b, respectively for slot 1200, and 1203a, 1203b,
respectively, for slot 1201. The rest of the OFDM symbols carry the
(coded) CQI bits.
[0052] The CQI data symbols convey the (coded) CQI information bits
by modulating the cyclic shifted (UE specific) CAZAC sequence with
QAM constellation points mapped from the (coded) CQI information
bits. Therefore, ten (coded) CQI bits can be transmitted with QPSK
in one slot per UE, using the four point constellation as shown in
FIG. 14 and FIG. 16, for example. The CQI RS symbols are treated
such that the cyclic shifted CAZAC sequence is modulated by 1 to
provide channel estimation for coherent demodulation of the CQI
data symbols.
[0053] ACK/NAK in UL is a 1-bit control response to each DL packet
to support hybrid ARQ (HARQ) retransmission. Depending on the
number of packets transmitted within one DL subframe, multiple
ACK/NAK bits may need to be transmitted by a UE. For example, with
multiple-input-multiple-output (MIMO) technology, a UE can be
scheduled with simultaneous transmission of two packets within one
subframe. Thus, an ACKNAK response of two ACK/NAK bits is needed.
In one embodiment of the invention, it is assumed the number of
ACK/NAK bits per UE per subframe is either one or two. However, in
other embodiments larger numbers of ACK/NAK bits may be
accommodated by increasing the QAM modulation order.
[0054] The ACKNAK response is mapped to a QAM constellation point,
which is transmitted in the second RS symbol in each slot, as shown
in FIG. 12. The same mapped ACKNAK QAM constellation point is
transmitted in the second RS symbol in both slots of a subframe. It
is not precluded that the ACKNAK response is mapped to different
constellation points, each of which is transmitted in an RS symbol
within the subframe, provided that the ACKNAK mapping scheme is
known to both the transmitter and the receiver.
[0055] Depending on the ACK/NAK information bits and the number of
ACKNAK bits, a certain QAM symbol (BPSK for one ACK/NAK bit and
QPSK for two ACKNAK bits) can be obtained to modulate/multiply the
cyclic shifted CAZAC sequence in the second CQI RS of a slot.
[0056] If a UE has not received a DL packet that requires an ACKNAK
response and therefore only CQI to transmit, then in the second CQI
RS, it may modulate/multiply the second CQI RS with the "NAK, NAK"
or "NAK" QAM symbol. It is beneficial to map the 2-bit "NAK, NAK"
response and 1-bit "NAK" response onto the same QAM symbol, in case
a DL grant is missed by the UE. For example, the 1-bit "NAK"
constellation point in FIG. 13 is the same as the 2-bit "NAK, NAK"
constellation point in FIG. 14. Moreover, the 1-bit "NAK"
constellation point in FIG. 15 is the same as the 2-bit "NAK, NAK"
constellation point in FIG. 16.
[0057] The Node-B can have prior knowledge on whether ACKNAK bits
are expected in the second CQI RS or not. If the Node-B knows there
are no ACK/NAK bits in the second CQI RS, then it demodulates the
second CQI RS by the "NAK, NAK" or "NAK" QAM symbol to provide
channel estimation for coherent demodulation of the CQI data
symbols. If the Node-B expects ACKNAK bits in the second CQI RS,
then it decodes the QAM symbol carried in the second CQI RS with
the channel estimation obtained from the first CQI RS. Further,
after ACKNAK demodulation and decoding on the second CQI RS, the
second RS can also serve as a channel estimate for CQI data
symbols. In another embodiment, a joint ACKNAK and CQI decoding can
be performed.
[0058] Further, in case there are more than two ACKNAK bits or some
additional UL control signaling bits (e.g. UL scheduling request)
to be transmitted together with CQI, a higher order QAM modulation
can be used in the second CQI RS symbol to convey the multiple UL
control signaling bits.
Discontinuous Transmission (DTX)
[0059] ACK/NAK DTX (discontinuous transmission) refers to the
scenario where the UE misses the DL grant and thus does not receive
any packet and transmits no ACK/NAK bit in UL. However, the NodeB
expects ACK/NAK from the UE. Moreover, the NodeB needs to detect
ACK/NAK DTX for proper HARQ operations. Referring again to FIG. 12,
a DTX response may also be included in the modulation mapping of
the second CQI RS symbol 1202b, 1203b, respectively, of each slot
1200, 1201.
[0060] FIG. 17 is an illustration of a mapping of two ACK/NAK Bits
and a DTX indicator to a pentamery phase shift keyed (5PSK)
constellation having five constellation points 1700.
[0061] FIG. 18 is an illustration of a mapping of one ACK/NAK Bit
and a DTX indicator to a tertiary phased shift keyed (3PSK)
constellation having three constellation points 1800.
[0062] For two ACK/NAK bits, there are five hypotheses to detect in
the receiver side (NodeB), i.e. [DTX], [ACK, ACK], [ACK, NAK],
[NAK, ACK], and [NAK, NAK]. For one ACK/NAK bit, there are three
hypotheses to detect, i.e. [DTX], [ACK], and [NAK].
TABLE-US-00002 TABLE 2 Modulation for 2 ACK/NAK Bits with DTX
Detection Slot 0 Slot 1 [DTX] {square root over (2)}/2 + j{square
root over (2)}/2 {square root over (2)}/2 + j{square root over
(2)}/2 [NAK, NAK] {square root over (2)}/2 + j{square root over
(2)}/2 -{square root over (2)}/2 - j{square root over (2)}/2 [NAK,
ACK] -{square root over (2)}/2 + j{square root over (2)}/2 {square
root over (2)}/2 - j{square root over (2)}/2 [ACK, ACK] -{square
root over (2)}/2 - j{square root over (2)}/2 {square root over
(2)}/2 + j{square root over (2)}/2 [ACK, NAK] {square root over
(2)}/2 - j{square root over (2)}/2 -{square root over (2)}/2 +
j{square root over (2)}/2
[0063] Table 1 shows an example of the proposed modulation scheme
for two ACK/NAK bits with DTX detection. The symbols in Table 1
represent the QPSK symbols, which modulate/multiply the cyclic
shifted CAZAC-like sequence in either slot 0 or slot 1. The design
principles are:
[0064] For DTX, the same QPSK symbol is transmitted in both slots
of a subframe;
[0065] For the four possibilities of two ACK/NAK bits, i.e. [NAK,
NAK], [NAK, ACK], [ACK, ACK], and [ACK, NAK], the QPSK symbol
transmitted in the second slot is the negative of the QPSK symbol
transmitted in the first slot.
TABLE-US-00003 TABLE 3 Modulation for 2 ACK/NAK Bits with DTX
Detection Slot 0 Slot 1 [DTX] {square root over (2)}/2 + j{square
root over (2)}/2 {square root over (2)}/2 + j{square root over
(2)}/2 [NAK, NAK] -{square root over (2)}/2 + j{square root over
(2)}/2 {square root over (2)}/2 - j{square root over (2)}/2 [NAK,
ACK] -{square root over (2)}/2 - j{square root over (2)}/2 {square
root over (2)}/2 + j{square root over (2)}/2 [ACK, ACK] {square
root over (2)}/2 - j{square root over (2)}/2 -{square root over
(2)}/2 + j{square root over (2)}/2 [ACK, NAK] {square root over
(2)}/2 + j{square root over (2)}/2 -{square root over (2)}/2 -
j{square root over (2)}/2
TABLE-US-00004 TABLE 4 Modulation for 2 ACK/NAK Bits with DTX
Detection Slot 0 Slot 1 [DTX] {square root over (2)}/2 + j{square
root over (2)}/2 {square root over (2)}/2 + j{square root over
(2)}/2 [NAK, NAK] -{square root over (2)}/2 - j{square root over
(2)}/2 {square root over (2)}/2 + j{square root over (2)}/2 [NAK,
ACK] {square root over (2)}/2 - j{square root over (2)}/2 -{square
root over (2)}/2 + j{square root over (2)}/2 [ACK, ACK] {square
root over (2)}/2 + j{square root over (2)}/2 -{square root over
(2)}/2 - j{square root over (2)}/2 [ACK, NAK] -{square root over
(2)}/2 + j{square root over (2)}/2 {square root over (2)}/2 -
j{square root over (2)}/2
TABLE-US-00005 TABLE 5 Modulation for 2 ACK/NAK Bits with DTX
Detection Slot 0 Slot 1 [DTX] {square root over (2)}/2 + j{square
root over (2)}/2 {square root over (2)}/2 + j{square root over
(2)}/2 [NAK, NAK] {square root over (2)}/2 - j{square root over
(2)}/2 -{square root over (2)}/2 + j{square root over (2)}/2 [NAK,
ACK] {square root over (2)}/2 + j{square root over (2)}/2 -{square
root over (2)}/2 - j{square root over (2)}/2 [ACK, ACK] -{square
root over (2)}/2 + j{square root over (2)}/2 {square root over
(2)}/2 - j{square root over (2)}/2 [ACK, NAK] -{square root over
(2)}/2 - j{square root over (2)}/2 {square root over (2)}/2 +
j{square root over (2)}/2
[0066] Tables 2-4 list other possible modulation schemes for two
ACK/NAK bits with DTX detection. Note any common phase rotation can
be applied to the proposed modulation (or all QPSK symbols) in
Tables 1-4. Alternatively, Tables 5-8 list modulation schemes for
two ACK/NAK bits with DTX detection.
TABLE-US-00006 TABLE 6 Modulation for 2 ACK/NAK Bits with DTX
Detection Slot 0 Slot 1 [DTX] j j [NAK, NAK] {square root over
(2)}/2 + j{square root over (2)}/2 -{square root over (2)}/2 -
j{square root over (2)}/2 [NAK, ACK] -{square root over (2)}/2 +
j{square root over (2)}/2 {square root over (2)}/2 - j{square root
over (2)}/2 [ACK, ACK] -{square root over (2)}/2 - j{square root
over (2)}/2 {square root over (2)}/2 + j{square root over (2)}/2
[ACK, NAK] {square root over (2)}/2 - j{square root over (2)}/2
-{square root over (2)}/2 + j{square root over (2)}/2
TABLE-US-00007 TABLE 7 Modulation for 2 ACK/NAK Bits with DTX
Detection Slot 0 Slot 1 [DTX] j j [NAK, NAK] -{square root over
(2)}/2 + j{square root over (2)}/2 {square root over (2)}/2 -
j{square root over (2)}/2 [NAK, ACK] -{square root over (2)}/2 -
j{square root over (2)}/2 {square root over (2)}/2 + j{square root
over (2)}/2 [ACK, ACK] {square root over (2)}/2 - j{square root
over (2)}/2 -{square root over (2)}/2 + j{square root over (2)}/2
[ACK, NAK] {square root over (2)}/2 + j{square root over (2)}/2
-{square root over (2)}/2 - j{square root over (2)}/2
TABLE-US-00008 TABLE 8 Modulation for 2 ACK/NAK Bits with DTX
Detection Slot 0 Slot 1 [DTX] j j [NAK, NAK] -{square root over
(2)}/2 - j{square root over (2)}/2 {square root over (2)}/2 +
j{square root over (2)}/2 [NAK, ACK] {square root over (2)}/2 -
j{square root over (2)}/2 -{square root over (2)}/2 + j{square root
over (2)}/2 [ACK, ACK] {square root over (2)}/2 + j{square root
over (2)}/2 -{square root over (2)}/2 - j{square root over (2)}/2
[ACK, NAK] -{square root over (2)}/2 + j{square root over (2)}/2
{square root over (2)}/2 - j{square root over (2)}/2
TABLE-US-00009 TABLE 9 Modulation for 2 ACK/NAK Bits with DTX
Detection Slot 0 Slot 1 [DTX] j j [NAK, NAK] {square root over
(2)}/2 - j{square root over (2)}/2 -{square root over (2)}/2 +
j{square root over (2)}/2 [NAK, ACK] {square root over (2)}/2 +
j{square root over (2)}/2 -{square root over (2)}/2 - j{square root
over (2)}/2 [ACK, ACK] -{square root over (2)}/2 + j{square root
over (2)}/2 {square root over (2)}/2 - j{square root over (2)}/2
[ACK, NAK] -{square root over (2)}/2 - j{square root over (2)}/2
{square root over (2)}/2 + j{square root over (2)}/2
[0067] Moreover, it is possible to design a 5-PSK modulation scheme
for two ACK/NAK bits with DTX detection. The 5 PSK symbols are
shown in FIG. 17, which illustrates five equal angular symbols for
two ACK/NAK Bits with DTX Detection. Some possible mappings between
the 5 PSK symbols to the ACK/NAK and DTX hypotheses are listed in
Tables 9-12. Other mappings using the 5 PSK symbols in FIG. 17 are
not precluded. Any common phase rotation can be applied to the 5
PSK symbols in FIG. 17.
TABLE-US-00010 TABLE 10 Modulation for 2 ACK/NAK Bits with DTX
Detection Slot 0 Slot 1 [DTX] W1 W1 [NAK, NAK] W2 W4 [NAK, ACK] W3
W5 [ACK, ACK] W4 W2 [ACK, NAK] W5 W3
TABLE-US-00011 TABLE 11 Modulation for 2 ACK/NAK Bits with DTX
Detection Slot 0 Slot 1 [DTX] W1 W1 [NAK, NAK] W3 W5 [NAK, ACK] W4
W2 [ACK, ACK] W5 W3 [ACK, NAK] W2 W4
TABLE-US-00012 TABLE 12 Modulation for 2 ACK/NAK Bits with DTX
Detection Slot 0 Slot 1 [DTX] W1 W1 [NAK, NAK] W4 W2 [NAK, ACK] W5
W3 [ACK, ACK] W2 W4 [ACK, NAK] W3 W5
TABLE-US-00013 TABLE 13 Modulation for 2 ACK/NAK Bits with DTX
Detection Slot 0 Slot 1 [DTX] W1 W1 [NAK, NAK] W5 W3 [NAK, ACK] W2
W4 [ACK, ACK] W3 W5 [ACK, NAK] W4 W2
[0068] For one ACK/NAK bit, Tables 12-16 show possible modulation
schemes with the same design principle as discussed above.
TABLE-US-00014 TABLE 14 Modulation for 1 ACK/NAK Bit with DTX
Detection Slot 0 Slot 1 [DTX] {square root over (2)}/2 + j{square
root over (2)}/2 {square root over (2)}/2 + j{square root over
(2)}/2 [ACK] {square root over (2)}/2 + j{square root over (2)}/2
-{square root over (2)}/2 - j{square root over (2)}/2 [NAK]
-{square root over (2)}/2 - j{square root over (2)}/2 {square root
over (2)}/2 + j{square root over (2)}/2
TABLE-US-00015 TABLE 15 Modulation for 1 ACK/NAK Bit with DTX
Detection Slot 0 Slot 1 [DTX] {square root over (2)}/2 + j{square
root over (2)}/2 {square root over (2)}/2 + j{square root over
(2)}/2 [ACK] -{square root over (2)}/2 - j{square root over (2)}/2
{square root over (2)}/2 + j{square root over (2)}/2 [NAK] {square
root over (2)}/2 + j{square root over (2)}/2 -{square root over
(2)}/2 - j{square root over (2)}/2
TABLE-US-00016 TABLE 16 Modulation for 1 ACK/NAK Bit with DTX
Detection Slot 0 Slot 1 [DTX] {square root over (2)}/2 + j{square
root over (2)}/2 {square root over (2)}/2 + j{square root over
(2)}/2 [ACK] -{square root over (2)}/2 + j{square root over (2)}/2
{square root over (2)}/2 - j{square root over (2)}/2 [NAK] {square
root over (2)}/2 - j{square root over (2)}/2 -{square root over
(2)}/2 + j{square root over (2)}/2
TABLE-US-00017 TABLE 17 Modulation for 1 ACK/NAK Bit with DTX
Detection Slot 0 Slot 1 [DTX] {square root over (2)}/2 + j{square
root over (2)}/2 {square root over (2)}/2 + j{square root over
(2)}/2 [ACK] {square root over (2)}/2 - j{square root over (2)}/2
-{square root over (2)}/2 + j{square root over (2)}/2 [NAK]
-{square root over (2)}/2 + j{square root over (2)}/2 {square root
over (2)}/2 - j{square root over (2)}/2
[0069] It is important to keep the same DTX symbols for one and two
ACK/NAK bits. In various embodiments, any common phase rotation can
be applied to the example modulation (or all QPSK symbols) in
Tables 12-16.
[0070] Alternatively, for one ACK/NAK bit with DTX detection, the
mapping scheme in Tables 17-20 are also applicable, where the
symbols W1, W2, and W3 are shown in FIG. 18. Note that W1, W2, and
W3 are evenly distributed within the unit circle. Note any common
phase rotation can be applied to the example modulation (or all
QPSK symbols) in Tables 17-20. Moreover, exp(x) denotes the
exponential function of x.
TABLE-US-00018 TABLE 18 Alternative Modulation for 1 ACK/NAK Bit
with DTX detection Slot 0 Slot 1 [DTX] W1 W1 [ACK] W2 W2 [NAK] W3
W3
TABLE-US-00019 TABLE 19 Alternative Modulation for 1 ACK/NAK Bit
with DTX detection Slot 0 Slot 1 [DTX] W1 W1 [ACK] W3 W3 [NAK] W2
W2
TABLE-US-00020 TABLE 20 Alternative Modulation for 1 ACK/NAK Bit
with DTX detection Slot 0 Slot 1 [DTX] W1 W1 [ACK] W2 W3 [NAK] W3
W2
TABLE-US-00021 TABLE 21 Alternative Modulation for 1 ACK/NAK Bit
with DTX detection Slot 0 Slot 1 [DTX] W1 W1 [ACK] W3 W2 [NAK] W2
W3
Combined ACKNAK and DTX
[0071] For ACK/NAK signaling in CQI RS, it is possible to treat DTX
as (NAK) or (NAK, NAK). Thus, in another embodiment, BPSK and QPSK
modulation can be utilized for one and two ACK/NAK bits,
respectively. Again, it is important that the DTX symbol is the
same for one and two ACK/NAK bits. Thus, the mapping illustrated in
Tables 21 and 22, or Tables 23 and 24, may be used where DTX is
treated the same as (NAK) or (NAK, NAK).
TABLE-US-00022 TABLE 22 1 ACK/NAK Bit with BPSK CS1.sub.CQI, RS A/N
Slot 0 Slot 1 (A.sub.1) CQI RS 1 CQI RS 2 CQI RS 1 CQI RS 2 (NAK) 1
{square root over (2)}/2 + j{square root over (2)}/2 1 {square root
over (2)}/2 + j{square root over (2)}/2 or DTX (ACK) 1 -{square
root over (2)}/2 - j{square root over (2)}/2 1 -{square root over
(2)}/2 - j{square root over (2)}/2
TABLE-US-00023 TABLE 23 2 ACK/NAK Bits with QPSK CS1.sub.CQI, RS
A/N Slot 0 Slot 1 (A.sub.1A.sub.2) CQI RS 1 CQI RS 2 CQI RS 1 CQI
RS 2 (NAK, NAK) 1 {square root over (2)}/2 + j{square root over
(2)}/2 1 {square root over (2)}/2 + j{square root over (2)}/2 or
DTX (NAK, ACK) 1 {square root over (2)}/2 - j{square root over
(2)}/2 1 {square root over (2)}/2 - j{square root over (2)}/2 (ACK,
NAK) 1 -{square root over (2)}/2 + j{square root over (2)}/2 1
-{square root over (2)}/2 + j{square root over (2)}/2 (ACK, ACK) 1
-{square root over (2)}/2 - j{square root over (2)}/2 1 -{square
root over (2)}/2 - j{square root over (2)}/2
TABLE-US-00024 TABLE 24 1 ACK/NAK Bit with BPSK CS1.sub.CQI, RS A/N
Slot 0 Slot 1 (A.sub.1) CQI RS 1 CQI RS 2 CQI RS 1 CQI RS 2 (NAK) 1
1 1 1 or DTX (ACK) 1 -1 1 -1
TABLE-US-00025 TABLE 25 2 ACK/NAK Bits with QPSK CS1.sub.CQI, RS
A/N Slot 0 Slot 1 (A.sub.1A.sub.2) CQI RS1 CQI RS 2 CQI RS 1 CQI RS
2 (NAK, NAK) 1 1 1 1 or DTX (NAK, ACK) 1 j 1 j (ACK, NAK) 1 -j 1 -j
(ACK, ACK) 1 -1 1 -1
[0072] Any rotations to the symbols (or subset of the symbols) in
Tables 21-24 are applicable, as long as the DTX symbol remains the
same for the one and two ACK/NAK bits.
System Examples
[0073] FIG. 19 is a block diagram illustrating operation of an eNB
and a mobile UE in the network system of FIG. 1. As shown in FIG.
19, wireless networking system 1900 comprises a mobile UE device
1901 in communication with an eNB 1902. The mobile UE device 1901
may represent any of a variety of devices such as a server, a
desktop computer, a laptop computer, a cellular phone, a Personal
Digital Assistant (PDA), a smart phone or other electronic devices.
In some embodiments, the electronic mobile UE device 1901
communicates with the eNB 1902 based on a LTE or E-UTRAN protocol.
Alternatively, another communication protocol now known or later
developed can be used.
[0074] As shown, the mobile UE device 1901 comprises a processor
1903 coupled to a memory 1907 and a Transceiver 1904. The memory
1907 stores (software) applications 1905 for execution by the
processor 1903. The applications 1905 could comprise any known or
future application useful for individuals or organizations. As an
example, such applications 1905 could be categorized as operating
systems (OS), device drivers, databases, multimedia tools,
presentation tools, Internet browsers, e-mailers,
Voice-Over-Internet Protocol (VOIP) tools, file browsers,
firewalls, instant messaging, finance tools, games, word processors
or other categories. Regardless of the exact nature of the
applications 1905, at least some of the applications 1905 may
direct the mobile UE device 1901 to transmit UL signals to the eNB
(base-station) 1902 periodically or continuously via the
transceiver 1904. In at least some embodiments, the mobile UE
device 1901 identifies a Quality of Service (QoS) requirement when
requesting an uplink resource from the eNB 1902. In some cases, the
QoS requirement may be implicitly derived by the eNB 1902 from the
type of traffic supported by the mobile UE device 1901. As an
example, VOIP and gaming applications often involve low-latency
uplink (UL) transmissions while High Throughput (HTP)/Hypertext
Transmission Protocol (HTTP) traffic can involve high-latency
uplink transmissions.
[0075] Transceiver 1904 includes uplink logic which may be
implemented by execution of instructions that control the operation
of the transceiver. Some of these instructions may be stored in
memory 1907 and executed when needed. As would be understood by one
of skill in the art, the components of the Uplink Logic may involve
the physical (PHY) layer and/or the Media Access Control (MAC)
layer of the transceiver 1904. Transceiver 1904 includes one or
more receivers 1920 and one or more transmitters 1922. The
transmitter(s) may be embodied as described with respect to FIGS.
2-18. In particular, as described above, a transmission signal
comprises at least one data symbol and at least one RS symbol. An
exemplary transmission signal comprising five data symbols and two
RS symbols is shown in FIG. 2. The first type of information is
transmitted in at least one data symbol, and the second type of
information is transmitted in at least one RS symbol. In this
embodiment, the first type of information is a channel quality
indicator (CQI) and the second type of information is an ACKNAK
response. The CQI is firstly mapped to a number of constellation
points, e.g. according to a quadrature amplitude modulation (QAM)
mapping scheme. The constellation points mapped from the CQI are
then transmitted on the data symbols, by modulating/multiplying
each data symbol with a corresponding constellation point. CQI
includes, but not limited to Rank Indicator (RI), Precoding Matrix
Indicator (PMI), Modulation and Coding Scheme (MCS), or
combinations thereof.
[0076] The ACKNAK response is firstly mapped to a constellation
point, e.g. according to a quadrature amplitude modulation mapping
scheme. The constellation point mapped from the ACKNAK response is
transmitted in the second RS symbol by modulating/multiplying the
reference signal with the constellation point. A pre-defined
reference signal is transmitted in the first RS symbol. It is not
precluded that a transmission signal can comprise more than two RS
symbols, where the ACKNAK response is transmitted in a subset of
the RS symbols and pre-defined reference signals are transmitted in
the rest RS symbols. The pre-defined reference signal transmitted
in each RS symbol can be the same. Alternatively, the pre-defined
reference signals can be different in different RS symbols,
provided these pre-defined reference signals are known to both the
transmitter and the receiver.
[0077] As shown in FIG. 19, the eNB 1902 comprises a Processor 1909
coupled to a memory 1913 and a transceiver 1910. The memory 1913
stores applications 1908 for execution by the processor 1909. The
applications 1908 could comprise any known or future application
useful for managing wireless communications. At least some of the
applications 1908 may direct the base-station to manage
transmissions to or from the user device 1901.
[0078] Transceiver 1910 comprises an uplink Resource Manager 1912,
which enables the eNB 1902 to selectively allocate uplink PUSCH
resources to the user device 1901. As would be understood by one of
skill in the art, the components of the uplink resource manager
1912 may involve the physical (PHY) layer and/or the Media Access
Control (MAC) layer of the transceiver 1910. Transceiver 1910
includes a Receiver 1911 for receiving transmissions from various
UE within range of the eNB and transmitters for transmitting data
and control information to the various UE within range of the
eNB.
[0079] Uplink resource manager 1912 executes instructions that
control the operation of transceiver 1910. Some of these
instructions may be located in memory 1913 and executed when
needed. Resource manager 1912 controls the transmission resources
allocated to each UE that is being served by eNB 1902 and
broadcasts control information via the physical downlink control
channel PDCCH. In particular, for the transmission of ACK/NAK, eNB
1902 arranges the cyclic shifted base sequences in the
time-frequency resource, as described above. The Node-B can have
prior knowledge on whether ACKNAK bits are expected in the second
CQI RS or not. If the Node-B knows there are no ACK/NAK bits in the
second CQI RS, then it demodulates the second CQI RS by the "NAK,
NAK" or "NAK" QAM symbol to provide channel estimation for coherent
demodulation of the CQI data symbols. If the Node-B expects ACKNAK
bits in the second CQI RS, then it decodes the QAM symbol carried
in the second CQI RS with the channel estimation obtained from the
first CQI RS. Further, after ACKNAK demodulation and decoding on
the second CQI RS, the second RS can also serve as a channel
estimate for CQI data symbols, as described in more detail
above.
[0080] FIG. 20 is a block diagram of mobile cellular phone 1000 for
use in the network of FIG. 1. Digital baseband (DBB) unit 1002 can
include a digital processing processor system (DSP) that includes
embedded memory and security features. Stimulus Processing (SP)
unit 1004 receives a voice data stream from handset microphone
1013a and sends a voice data stream to handset mono speaker 1013b.
SP unit 1004 also receives a voice data stream from microphone
1014a and sends a voice data stream to mono headset 1014b. Usually,
SP and DBB are separate ICs. In most embodiments, SP does not embed
a programmable processor core, but performs processing based on
configuration of audio paths, filters, gains, etc being setup by
software running on the DBB. In an alternate embodiment, SP
processing is performed on the same processor that performs DBB
processing. In another embodiment, a separate DSP or other type of
processor performs SP processing.
[0081] RF transceiver 1006 includes a receiver for receiving a
stream of coded data frames and commands from a cellular base
station via antenna 1007 and a transmitter for transmitting a
stream of coded data frames to the cellular base station via
antenna 1007. Transmission of the PUSCH data is performed by the
transceiver using the PUSCH resources designated by the serving
eNB. In some embodiments, frequency hopping may be implied by using
two or more bands as commanded by the serving eNB. In this
embodiment, a single transceiver can support multi-standard
operation (such as EUTRA and other standards) but other embodiments
may use multiple transceivers for different transmission standards.
Other embodiments may have transceivers for a later developed
transmission standard with appropriate configuration. RF
transceiver 1006 is connected to DBB 1002 which provides processing
of the frames of encoded data being received and transmitted by the
mobile UE unite 1000.
[0082] The EUTRA defines SC-FDMA (via DFT-spread OFDMA) as the
uplink modulation. The basic SC-FDMA DSP radio can include discrete
Fourier transform (DFT), resource (i.e. tone) mapping, and IFFT
(fast implementation of IDFT) to form a data stream for
transmission. To receive the data stream from the received signal,
the SC-FDMA radio can include DFT, resource de-mapping and IFFT.
The operations of DFT, IFFT and resource mapping/de-mapping may be
performed by instructions stored in memory 1012 and executed by DBB
1002 in response to signals received by transceiver 1006.
[0083] For ACK/NAK transmission, a transmitter(s) within
transceiver 1006 may be embodied as described with respect to FIGS.
2-18. In particular, as described above, for the transmission of
ACK/NAK a transmission signal may comprise at least one data symbol
and at least one RS symbol. An exemplary transmission signal
comprising five data symbols and two RS symbols is shown in FIG. 2.
The first type of information is transmitted in at least one data
symbol, and the second type of information is transmitted in at
least one RS symbol. In this embodiment, the first type of
information is a channel quality indicator (CQI) and the second
type of information is an ACKNAK response. The CQI is firstly
mapped to a number of constellation points, e.g. according to a
quadrature amplitude modulation (QAM) mapping scheme. The
constellation points mapped from the CQI are then transmitted on
the data symbols, by modulating/multiplying each data symbol with a
corresponding constellation point. CQI includes, but not limited to
Rank Indicator (RI), Precoding Matrix Indicator (PMI), Modulation
and Coding Scheme (MCS), or combinations thereof.
[0084] The ACKNAK response is firstly mapped to a constellation
point, e.g. according to a quadrature amplitude modulation mapping
scheme. The constellation point mapped from the ACKNAK response is
transmitted in the second RS symbol by modulating/multiplying the
reference signal with the constellation point. A pre-defined
reference signal is transmitted in the first RS symbol. It is not
precluded that a transmission signal can comprise more than two RS
symbols, where the ACKNAK response is transmitted in a subset of
the RS symbols and pre-defined reference signals are transmitted in
the rest RS symbols. The pre-defined reference signal transmitted
in each RS symbol can be the same. Alternatively, the pre-defined
reference signals can be different in different RS symbols,
provided these pre-defined reference signals are known to both the
transmitter and the receiver.
[0085] DBB unit 1002 may send or receive data to various devices
connected to universal serial bus (USB) port 1026. DBB 1002 can be
connected to subscriber identity module (SIM) card 1010 and stores
and retrieves information used for making calls via the cellular
system. DBB 1002 can also connected to memory 1012 that augments
the onboard memory and is used for various processing needs. DBB
1002 can be connected to Bluetooth baseband unit 1030 for wireless
connection to a microphone 1032a and headset 1032b for sending and
receiving voice data. DBB 1002 can also be connected to display
1020 and can send information to it for interaction with a user of
the mobile UE 1000 during a call process. Display 1020 may also
display pictures received from the network, from a local camera
1026, or from other sources such as USB 1026. DBB 1002 may also
send a video stream to display 1020 that is received from various
sources such as the cellular network via RF transceiver 1006 or
camera 1026. DBB 1002 may also send a video stream to an external
video display unit via encoder 1022 over composite output terminal
1024. Encoder unit 1022 can provide encoding according to
PAL/SECAM/NTSC video standards.
[0086] As used herein, the terms "applied," "coupled," "connected,"
and "connection" mean electrically connected, including where
additional elements may be in the electrical connection path.
"Associated" means a controlling relationship, such as a memory
resource that is controlled by an associated port. While the
invention has been described with reference to illustrative
embodiments, this description is not intended to be construed in a
limiting sense. Various other embodiments of the invention will be
apparent to persons skilled in the art upon reference to this
description. For example, a larger or smaller number of symbols
then described herein may be used in a slot.
[0087] FIGS. 2-18 illustrate various embodiments and various modes
of operation. A particular embodiment may be arranged to perform
all or a portion of the various modes illustrated in FIGS.
2-18.
[0088] It is therefore contemplated that the appended claims will
cover any such modifications of the embodiments as fall within the
true scope and spirit of the invention.
* * * * *