WO2011066686A1

WO2011066686A1 - Method, apparatus and system of encoding information

Info

Publication number: WO2011066686A1
Application number: PCT/CN2009/075305
Authority: WO
Inventors: Jianghua Liu; Wennsrtom Mattias
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2009-12-04
Filing date: 2009-12-04
Publication date: 2011-06-09
Also published as: WO2011066812A1

Abstract

In the disclosed method, a transmitter in a wireless communication system determines a set of M first type sequences and a set of N second type sequences; the transmitter selects K sequences from the set of first type sequences, where each selected sequence defines one antenna or antenna port; the transmitter selects J sequences, irrespective of the K selected sequences, from the set of second type sequences; the transmitter associates the J selected sequences with the K defined antennas or antenna ports, wherein each selected second type sequence associates with only one antenna or antenna port, each antenna or antenna port being associated with at least one selected second type sequence, and a number of information bits are encoded by the selection of K and J sequences and the sequence association.

Description

METHOD, APPARATUS AND SYSTEM OF ENCODING INFORMATION

Technical Field

The present invention relates to a wireless communication field, particularly relates to a method, apparatus and system of encoding information.

Background

A simplified transmitter structure in a wireless communication system is shown in Fig.1 . A pair of sequences, i.e. Sequence A (101 ) and Sequence B (102) are used for modulation data transmission and for Reference Signal (RS) transmission respectively. The signals are then multiplexed and transmitted over a wireless link. There are two sets of sequences for modulation data and RS transmission respectively. Sequence A and Sequence B are correspondingly taken from the two sets of sequences.

In 3GPP Long Term Evolution (LTE) system, when transmitting data, e.g.

ACK/NACK, on physical uplink control channel (PUCCH) in response to downlink dynamic scheduling transmission, two sets of sequences [So, S-i , S2, SM-I] and [mo, m-i , ITI2, . . . , ΓΠΜ-Ι] are explicitly or implicitly reserved for modulation data and RS transmission respectively, where s, and 171, (0 ^ i ^ M-1 , 1 M) are paired sequences. However there is only one ACK/NACK symbol to be transmitted on PUCCH for each UE in LTE, hence only the first sequence pair (So, mo) is used for transmission on one antenna and the remaining sequence pairs are not utilized. Furthermore, when the sequence pair (So, mo) is used, So is modulated by an ACK/NACK symbol, e.g. BPSK or QPSK, to convey one or two bits information respectively.

The LTE PUCCH multiplexing and transmission structure may be reused in the subsequent LTE-Advanced system to maintain backward compatibility. Different from LTE, LTE-Advanced supports carrier aggregation to obtain wider system bandwidths where two or more Component Carriers (CCs) are aggregated. Up to five aggregated CCs shall be supported in an LTE-Advanced system.

When carrier aggregation is supported, the ACK/NACK information corresponding to the data transmitted on each aggregated downlink CC needs to be reported in uplink, resulting in an increase of ACK/NACK information overhead compared to the LTE system with only one CC. For instance, when ACK/NACK information corresponding to the data transmitted over all five downlink CCs are transmitted in uplink, there will be up to ten bits ACK/NACK information to be transmitted on PUCCH if there are up to two bits ACK/NACK for each aggregated CC. But the conventional LTE PUCCH scheme can only transmit at most two bits information on PUCCH for one UE.

In 3GPP document R1 -093052, titled "Performance of UL multiple antenna transmission for PUCCH", by Huawei, in 3GPP RAN1 #58, Spatial Orthogonal Resource Spatial Multiplexing (SORSM) is proposed for transmitting multiple ACK/NACK bits when there are multiple transmit antennas. In this scheme, two modulation data sequences (s-i , S2) and two RS sequences (m-i , ITI2) are allocated; and only the predefined combination (s-i , m-i) and (S2, ITI2) are used on two antennas respectively. The receiver knows the information about the usage of two sequence pairs; therefore it is unnecessary to signal which sequence pairs to be used. On each antenna, one ACK/NACK symbol in the form of QPSK modulation is transmitted by using (s,, m,) (1 =¾ i =¾ 2); hence there are two ACK/NACK QPSK modulation symbols transmitted, i.e. up to 4 bits information are conveyed.

Summary

The inventors of this invention discover, in the process of making this invention, the conventional scheme in 3GPP document R1 -093052 does not apply to UEs with single transmit antenna, and the single carrier property of UEs would then be destroyed. Another drawback is that it is incapable to transmit up to 10 bits ACK/NACK information to support LTE-A carrier aggregation.

A new scheme with the capability to transmit more information in terms of number of bits than the conventional method is needed.

In the disclosed method, a transmitter in a wireless communication system determines a set of M first type sequences and a set of N second type sequences; the transmitter selects K sequences from the set of first type sequences, where each selected sequence defines one antenna or antenna port; the transmitter selects J sequences, irrespective of the K selected sequences, from the set of second type sequences; and the transmitter associates the J selected sequences with the K defined antennas or antenna ports, wherein each selected second type sequence associates with only one antenna or antenna port, each antenna or antenna port being associates with at least one selected second type sequence; and a number of information bits are encoded by the selection of K and J sequences and the sequence association.

According to the embodiments of the present invention, the combination of first type sequences with second type sequences is increased due to the sequence selection and the sequence association, i.e. the selection of J sequences is made irrespective of the selection of K sequences. Because a number of bits information, i.e. the number of combinations, is encoded by the sequence selection and the sequence association, more information bits can be encoded compared to a conventional method. Meanwhile, since single antenna UE would still be able to transmit more bits information under this innovative scheme, the single carrier property of UEs is preserved. After the selection of the two types sequence and the association of the sequences, each antenna will have the same transmission structure as LTE system, so the present invention would be backward compatible to conventional systems.

Brief description of the drawings

Methods, apparatus, and system according to the present invention will now be described in detail with reference to the accompanying drawings, in which:

Figure 1 is a schematic and simplified illustration of a transmitter structure in prior art;

Figure 2 is a schematic and simplified illustration of a multiplexing structure of DRS and ACK/NACK in one RB according to an embodiment;

Figure 3 is an example of the mapping of PDCCH to CCEs according to an embodiment;

Figure 4 is a schematic and simpl fied llustration of an encoding method;

Figure 5 is a schematic and simpl fied llustration of a transmitter;

Figure 6 is a schematic and simpl fied llustration of a transmitter;

Figure 7 is a schematic and simpl fied llustration of a transmitter;

Figure 8 is a schematic and simpl fied llustration of a transmitter; Figure 9 is a schematic and simplified illustration of a transmitter;

Figure 10 is a schematic and simplified illustration of a transmitter;

Figure 1 1 is a schematic and simplified illustration of a wireless communication system with a receiver and a transmitter;

Figure 12 is a schematic and simplified illustration of a non-transitory computer-readable storage medium;

Figure 13 is a schematic and simplified illustration of a chip used in a transmitter. Detailed Description

When referred to hereafter, the terminology "UE" includes a user equipment, a mobile station, a fixed or mobile subscriber unit, a pager, a cellular telephone, a personal digital assistant (PDA), a computer, or other type of user device capable of wireless transmissions. When referred to hereafter, the terminology "eNB" includes but is not limited to a base station, eNode B. Node B, a site controller, an access point (AP), or other type of transceiver device of receiving wireless transmissions.

In a wireless communication system, e.g. 3GPP Long Term Evolution (LTE) system, some control information needs to be transmitted on the uplink (from UE to eNB) control channel for assisting the communication of information between eNB and UE. For instance, acknowledgment (ACK/NACK) is the response to a completed downlink (from eNB to UE) transmission; Channel Quality Indicator (CQI) is used by eNB for performing scheduling and link adaptation for a subsequent transmission to the UE; Scheduling Request (SR) is used by the UE for requesting a subsequent uplink resource allocation; and Channel State Information (CSI) is used by eNB to generate subsequent transmission waveforms.

To transmit such control information, a certain number of uplink time- frequency resources, e.g. Resource Blocks (RB), are reserved. Corresponding to each RB, there are two sets of sequences which are used for the transmission of control signalling and Demodulation RS (DRS) respectively. The sequences within each set are mutually orthogonal to ensure low interference when used in parallel. The two sets of sequences are denoted as the data sequence set and the DRS sequence set respectively for exemplification in the remainder of this disclosure. For each UE, one data sequence from the data sequence set and a corresponding DRS sequence from the DRS sequence set is allocated.

After sequence pair allocation and resource allocation, e.g. RB allocation, each UE will modulate the allocated data sequence by the control information to be transmitted. Then the modulated data sequence and DRS sequence are transmitted simultaneously as shown in Figurel . At the receiver side, eNB first uses the DRS sequence to estimate the channel; and then the estimated channel is used for demodulation of the control information.

In an exemplified embodiment, a UE can transmit uplink information using the following data structure.

When a UE transmits uplink control information to an eNB, the uplink control information will be confined to one RB which may contain 12 sub-carriers and 6 or 7 symbols depending on a cyclic prefix (CP) size. Without loss of generality, it is assumed that there are 7 symbols per RB in the following description. The uplink control information can be transmitted on PUCCH. For example, the acknowledgment (ACK/NACK) in response to downlink packet transmission is transmitted on PUCCH.

In the RB for uplink control information transmission, i.e. PUCCH, three symbols are used for DRS transmission, and the remaining four symbols are used for uplink control information transmission. The uplink control information may be ACK/NACK, SR, CQI, or CSI. Without loss of generality, this embodiment takes ACK/NACK for example to describe the RB structure. The multiplexing structure of DRS and ACK/NACK in one RB is illustrated in figure 2.

In each time slot of transmitting ACK/NACK on PUCCH, a UE will use one DRS from a set of available DRSs to enable the use of coherent detection of the control information.

A sequence with length 12 is used to transmit ACK/NACK or DRS in each symbol. Given a base sequence of length 12, a set of 12 sequences are generated. These are obtained by multiplication with a linear phase with slope ΙπαΙΧΙ as follows r^a(n) = e^{j2ma i n}r(n n = Ο,Ι,.,.,Π; α = 0,1,...,11 (1 ) where r(n) is the base sequence with length 12, an0 r^a(n) is the modified base sequence. The linear phase shift operations in formula (1 ) are performed in frequency domain and a linear phase shift in frequency domain corresponds to a cyclic shift in time domain. Therefore, the 12 frequency domain sequences in formula (1 ) correspond to 12 different cyclic shifts of the base sequence in the time domain. These 12 sequences are orthogonal in the time domain due to this particular choice of the linear phase shift slopes ΙπαΙΧΙ .

If each UE uses a cyclic shift (or equivalent^ a phase slope ΙπούΥΙ ) for its ACK/NACK and a cyclic shift (or equivalently a phase slope ΙπαΙΧΙ ) for its DRS, and different UEs are assigned ACK/NACK or DRS through the cyclic shifts; there are at most 12 UEs multiplexing together per RB. In various embodiments of this disclosure, there are three symbols available for DRS and four symbols available for ACK/NACK in the RB structure. In order to further improve UE multiplexing capacity, code covering in the time domain is used. Three orthogonal sequences (OS) of length 3 are used for DRS. Three orthogonal sequences (OS) of length 4 are used for ACK/NACK. The three orthogonal sequences (OS) for DRS are shown in Table 1 . The three orthogonal sequences (OS) for ACK/NACK are shown in Table 2.

Table 2 OS for ACK/NACK code covering in the time domain for DRS is illustrated in Table 3.

DRS

Table 3 code covering in the time domain for DRS

According to the above structure, it can be observed that the sequence used for DRS is a two dimension sequence, i.e. frequency and time domain sequence. Using this two dimension sequence, there will be K=12^*3=36 sequences available for DRS. Similarly, there will be 36 two dimension sequences for ACK/NACK. Hence there are two sets of sequences, a data (ACK/NACK) sequence set and a DRS sequence set in one RB, where each sequence in the data sequence set is corresponding to one sequence in the DRS sequence set.

The 36 sequences in each sequence set are numbered as k=0, 1 ... 35. The index of sequence is related to the cyclic shift and OS. For example, the relation between the sequence index and the cyclic shift and OS is illustrated in Table 4.

7 k=7 k=19 k=31

8 k=8 k=20 k=32

9 k=9 k=21 k=33

10 k=10 k=22 k=34

1 1 k=1 1 k=23 k=35

Table 4 The relation between the sequence index and the cyclic shift and OS

Furthermore, A_shij_t is defined as the cyclic shift difference between two adjacent sequences using the same OS, and it can be different from one, considering multipath delay spreads for the given cell deployment. In various embodiments of this disclosure, three candidate values {1 , 2, 3} for A_shif_t are used, which are configured by eNB through higher layer signalling. For example, if A_sh = 2 then there are only

18 sequences available.

In the downlink, a broadcast channel is used for transmission of control information to the UEs from an eNB. The information in this broadcast channel is composed of multiple segments of information, denoted control channel elements (CCEs). Each UE is allocated one or several consecutive CCEs and receives its dedicated control information, denoted physical downlink control channel (PDCCH) in its allocated CCE segments. The number of allocated CCEs per PDCCH is 1 , 2, 4 or 8. An example of the mapping of PDCCH to CCEs is given in Figure 3 where four UEs are assumed; and UE#1 and UE#2 use one CCE each; and UE#3 and UE#4 use two CCEs each.

The PDCCH contain information about where and in which format a downlink data burst, denoted physical downlink shared channel (PDSCH), or an uplink data burst, denoted physical uplink shared channel (PUSCH) is transmitted. The UE first finds and reads the PDCCH, then receives the PDSCH and decode its message. At a later point in time, the UE sends an ACK/NACK in response to the received PDSCH message in the uplink to the eNB.

To avoid explicit scheduling of which data and/or DRS sequence(s) to be used for ACK/NACK transmission, the data and/or DRS sequence to be used by the UE is implicitly determined by the position of the first CCE of PDCCH assigned for the UE among all the transmitted PDCCHs in the downlink and the number of CCEs of the PDCCH . There may be a predefined mapping relation between the CCE index and the index of employed data and/or DRS sequence, but the mapping relation may be different for data sequence and DRS sequence. Referring to Figure 3, as an example, assume the mapping relation between CCE index and data and/or DRS sequence is k_data=CCE index and k_DRs=CCE index+3. Then UE#1 will be assigned kdata=0, and k_DRs=3 since its PDCCH starts with CCEO. UE#4 will be assigned k_data=4, 5, and k_DRs=7, 8 since its PDCCH has two CCEs, CCE4 and CCE5.

In this way, each UE knows uniquely which data and/or DRS sequence(s) to be used when transmitting the PUCCH and the eNB uniquely knows which data and/or DRS sequence(s) to assume when demodulating the PUCCH from each UE. If the number of CCEs is more than 1 , e.g. 2, 4 or 8, there will be more than one data and/or DRS sequence available. However, in a conventional LTE system, only one data and/or DRS sequence corresponding to the index of the first CCE is used due to the requirement of single antenna transmission and single carrier property; and the remaining sequences are unused. In this disclosure, however, all the available data and DRS sequences would be used for improving the control channel capacity.

The two sets of sequences may also be obtained through explicit allocation by eNB, e.g. high layer Radio Resource Control (RRC) signalling. For instance, the used DRS and data sequence are explicitly allocated by eNB for CQI transmission.

Preferably, all available sequences in the sequence sets are utilized for maximizing the capacity of information transmission in a wireless communication system. More bits information may be encoded and transmitted in the way of this disclosure than the schemes in a conventional method, in which only two predefined sequence pairs, e.g. (So, mo) and (s-i , m-i), are transmitted on two antennas respectively.

Generally speaking, in various embodiments of this disclosure, there are two sets of sequences, a first type sequences [mo, m-i , rri2, ITIM-I] and a second type sequences [So, S-i , S2, SN-I], available for information transmission for one UE, where M and N are positive integers, and M+N>2. These two sets of sequences for one UE can be obtained implicitly (e.g. by a number of CCEs of PDCCH) or explicitly (e.g. by high layer RRC signalling).

The information encoding is performed by the selection and association of K first type sequences and J second type sequences, where K and J are positive integers, and 1≤K≤J<M, N. The selection of J sequences is made irrespective of the K selected sequences. In a conventional system, where once the RS sequence is selected, the predefined data sequence will be automatically decided by the selected RS sequence.

When selecting J sequences from the second type sequence set, the number of combinations is C , particularly the indices of the J selected

sequences are arranged in descending or ascending order. Similarly, when selecting

K sequences from the first type sequence set, the number of combinations is C Mi and each of the K selected sequences defines an antenna port. When associating the selected J second type sequences with the K defined antenna ports, each of the selected J sequences is associated with only one antenna port, and each antenna port associates with at least one of the J sequences. In this way, the total number of combinations is C^ xC^ , hence the number of information bits that may be encoded by this sequence selection is log₂(cjv xc|^ ) , where means the largest integer which is smaller than a . A particular case is, when part of the combinations C_N ^J x CM is not valid, e.g. a receiver does not identify these combinations, that the transmitter would not use these invalid combinations to encode information. An improvement is that the transmitter would only use the valid combinations or selections to encoding information.

When associating the selected J second type sequences with the K defined antenna ports, particularly J=K, the selected K second type sequences may be further permuted resulting in K\ permutation and combination. Then the number of possibilities for selection will be increased to C^ x P^ corresponding to

|_log₂(c xP )J bits information where

^N (N - K)l

In various embodiments of the disclosure, the second type sequences would be a set of data sequences for data transmission; and the first type sequences would be a set of DRS sequences for coherent demodulation of the data transmitted using the data sequence. Without loss of generality, the number of selected sequences from the two sets of sequence may be the same, e.g. J=K. For the selected K DRS sequences, they would define K antennas, and for each antenna there is one corresponding data sequence from selected J data sequences.

Based on the selected J data sequences and K DRS sequences defining K antennas, up to J data symbols, or modulation symbols, can be transmitted by modulating the selected data sequences. Given the number of transmitted modulation symbols L and the modulation order n (e.g. 2, 3 and 4 corresponding to QPSK, 8PSK and 16QAM respectively), the total number of information bits to be transmitted is \og₂(c_N ^J x C^ x 2^nL )\ or (l log₂ c x c£ \+ nx LJ , which depends on whether a number of information bits is jointly encoded or separately encoded, i.e. the information bits are divided into two parts, one of which is used for sequence selection and sequence association, the other part of which is used for modulation symbols.

The present disclosure will now be illustrated by the following embodiments. An exemplary embodiment:

Refer to Figure 4; an exemplary method embodiment of this disclosure is illustrated. The method of information encoding in a wireless communication system comprising:

Block 401 : determining, by a transmitter of the wireless communication system, a set of M first type sequences and a set of N second type sequences, wherein M and N are positive integers, and M+N>2;

Block 402: selecting, by the transmitter, K sequences from the set of first type sequences, wherein K is a positive integer, K^ 1 , and each selected sequence defines an antenna port;

Block 403: selecting, by the transmitter, J sequences, irrespective of the K selected sequences, from the set of second type sequences, wherein J is a positive integer, and K=¾J;

Block 404: associating, by the transmitter, the J selected sequences with the K defined antenna ports, wherein each selected second type sequence associates with only one antenna port, each antenna port being associated with at least one selected second type sequence, and a number of information bits are encoded by sequence selection of K and J sequences and said sequence association.

Another exemplary embodiment: Assume that two sets of sequences contain two sequences each, e.g. [So, s-i] and [mo, m-i]. Then there are 4 possible sequence pairs of associated data sequence and RS sequence if selecting one sequence from each set, i.e. (So ,rrio) (So ,m-i) (Si ,m₀) and (Si ,m-i). Hence log₂(4) = 2 bits can be encoded by the sequence selection and sequence association. Furthermore, the selected data sequence is modulated by an ACK/NACK or CQI QPSK symbol corresponding to 2 bits; and the modulated data sequence and the selected RS sequence are transmitted together over single transmit antenna. Therefore, 4 bits of information in total can be transmitted for a UE with single transmit antenna. However, in a conventional method according to prior art, 4 bits of information transmission can't be implemented by a UE with single transmit antenna.

Another exemplary embodiment:

Assume that two sets of sequences contain four sequences each; there are two transmit antennas as a conventional method; and one sequence pair (e.g. (s₀ ,m₀) (so ,mi) (si ,m₀), ...(S2, m₀), (S3, m₀) ... and (S3 ,m₃)) per antenna is needed. To select two sequences from each set, there are c = 6 possibilities to select two RS sequences which define one antenna each; and similarly c = 6 possibilities to select two data sequences. When associate the two selected data sequences with two defined antennas, there would be two possibilities if considering the permutation of the two data sequences, wherein each selected data sequence associates with only one antenna port, and each antenna port associates with at least one selected data sequence. Hence in total there are 6^*6^*2=72 possibilities for sequence selection and sequence association. That is |_log₂72j = 6 bits of information would be encoded by the sequence selection and sequence association. The data sequence of each sequence pair is modulated by an ACK/NACK QPSK symbol, multiplexed and transmitted on one antenna as shown in Figure 1 , which is compatible with the current LTE scheme. Therefore the transmission of 10 bits of information in total can be supported by the mechanism of this example embodiment. Embodiment 1 : One embodiment of the present disclosure will now be described with reference to Table 5 showing an encoding scheme for transmitting information in a wireless communication system, and Figure 5 showing a transmitter thereof.

Given a data sequence set with four sequences (So, S-i , S2, S3) and a DRS sequences set with four sequences (mo, mi ITI2, ITI3) as well available for one UE, the available two sets of sequences may be obtained implicitly or explicitly. The combination of data sequence and DRS sequence will include 16 possibilities such as (So, mo), (So, m-i ), (s-i , mo), (s-i , m-i) when the UE selects one data sequence from the data sequence set and one DRS sequence from the DRS sequence set for transmission on single antenna defined by the selected one DRS sequence. Therefore four (log2 ( 6) =4) bits of information would be encoded by selection and association of the data sequence and the DRS sequence illustrated in Table 5. This means apart from s, (0<i<4) being modulated by an ACK/NACK symbol, e.g. BPSK or QPSK, to convey one or two bits of information respectively, four bits of information would be encoded, e.g. four additional ACKs/NACKs would be encoded.

Table 5

Referring to Figure 5, one data sequence Sj (0<i<4) and one DRS sequence rrij (0<j<4) are chosen and associated together for encoding information, and then the two sequences are transmitted on a single antenna defined by the selected DRS sequence, furthermore s, (0<i<4) is modulated by an ACK/NACK symbol, i.e. BPSK or QPSK. For example, the transmitter chooses (so, m₀) to transmit; when a receiver receives (so, m₀), then it knows it is [0000] being transmitted, e.g. four ACKs are encoded and transmitted.

In this embodiment, the mapping relation between the encoded information bits and sequence combination is only for illustration, and does not exclude another mapping scheme. Compared to a conventional method, the mechanism of this embodiment would transmit 5 bits of information, i.e. 4 bits plus 1 bit if using BPSK modulation, or 6 bits information, i.e. 4 bits plus 2 bits if using QPSK modulation, over single transmit antenna, which shows not only larger capacity but adaptation for UEs with single transmit antenna as well.

What's more, each of the selected sequence pairs is modulated, multiplexed and transmitted on one antenna, which is compatible with the conventional LTE scheme.

Embodiment 2:

Another embodiment of the present disclosure will now be described with reference to Table 6 showing an encoding scheme for transmitting information in a wireless communication system, and Figure 6 showing a transmitter thereof.

Given a data sequence set with two sequences (So, S-i ) and a DRS set with two sequences (mo, m-i ) available for one UE, the available two sets of sequences may be obtained implicitly or explicitly. Two data sequences and two DRS sequences are selected and associated for transmission on two antennas, where each DRS sequence defines one antenna or antenna port. The combination include [(So, mo), (s-i , m-i )] and [(s-i , m₀), (So, m-i )], so one additional bit information would be encoded by the sequence selection and sequence association, e.g. one additional ACK/NACK would be encoded. Furthermore, Si and So are modulated by an ACK/NACK symbol, i.e. BPSK or QPSK, to convey one or two bits information respectively.

Table 6

Refer to Figure 6, two data sequences Sj, Sj (0<i, j<2) and two DRS sequences rrij (0<j<2) are chosen and associated for encoding information, and then they are transmitted on two antennas, where each of selected DRS sequence defines one antenna or antenna port; furthermore Sj, Sj (0<i, j<0) is modulated by an ACK/NACK symbol, i.e. BPSK or QPSK, to convey one or two bits information respectively. For example, the transmitter chooses [(s₀, m₀), (Si , ITH)] to transmit; when a receiver receives [(so, m₀), (si , mi)], then it knows it is [0] being transmitted, e.g. one ACK is encoded and transmitted.

In this embodiment, the mapping relation between the additional information bit and sequence combination is only for illustration, and does not exclude another mapping scheme. Compared to a conventional system using the predefined sequence pair on each antenna, the mechanism of this embodiment would transmit one additional information bit [bo] by sequence selection and sequence association which forms sequence pairs, e.g. one additional ACK/NACK is transmitted in this embodiment.

What's more, one of the selected sequence pairs (e.g. (So, mo), (s-i , m-i), (s-i , m₀), (So, m-i )) is modulated, multiplexed and transmitted on each antenna, which is compatible with the conventional LTE scheme.

Embodiment 3:

Another embodiment of the present disclosure will now be described with reference to Table 7 showing an encoding scheme for transmitting information in a wireless communication system, and Figure 7 showing a transmitter thereof.

Given a data sequence set with three sequences (So, S-i , S₂) and a DRS sequence set with three sequences (mo, m-i , rri₂) available for one UE, the available two sets of sequences may be obtained implicitly or explicitly. Two data sequences and two DRS sequences are selected and associated for transmission on two antennas, where each of the selected DRS sequence defines one antenna. There are three possibilities to select two DRS sequences and three possibilities to select two data sequences, in addition there are two possibilities to associate the selected data and DRS sequences considering permutation. Therefore at least four additional bits information would be encoded by the sequence selection and sequence association which forms sequence pairs, e.g. four additional ACKs/NACKs can be encoded. Furthermore So and Si are modulated by an ACK/NACK symbol, i.e. BPSK or QPSK, to convey one or two bits information respectively.

Table 7

Refer to Figure 7, two data sequence S, and Sj (0<i, j<3) and two DRS sequence m_k and η\· (0<k, k'<2) are chosen and associated for encoding information; and then they are transmitted on two antennas, where each DRS sequence defines one antenna or antenna port; furthermore s, or Sj (0<i, j<0) is modulated by an ACK/NACK symbol, i.e. BPSK or QPSK, to convey one or two bits information respectively. For example, the transmitter chooses [(so, m₀), (si , mi)] to transmit; when a receiver receives [(so, m₀), (si, mi)], then it knows it is [0000] being transmitted, e.g. four ACKs are encoded and transmitted.

In this embodiment, the mapping relation between the additional information bit and sequence combination is only for illustration, and does not exclude another mapping scheme. Compared to a conventional system, the mechanism of this embodiment would transmit more information bits by sequence selection and sequence association. What's more, each of the selected sequence pairs (e.g. (s,, m_k), (S_j, m_k')) is modulated, multiplexed and transmitted on each antenna, which is compatible with the conventional LTE scheme.

Embodiment 4:

Another embodiment of the present disclosure will now be described with reference to Table 8 showing an encoding scheme for transmitting information in a wireless communication system.

Given a data sequence set with three sequences (So, S-i , S2) and a DRS sequences set with three sequences (mo, m-i , ITI2) available for one UE, the available two sets of sequences may be obtained implicitly or explicitly. One data sequence and one DRS sequence are selected from the corresponding sequence sets and are associated forming a sequence pair to be transmitted on one antenna. In principle there are nine combinations, and at most 3 bits information would be encoded by such sequence selection and sequence association. If there is only two bits information to be encoded, it would be sufficient to use only four combinations. In order to reduce the complexity of blind detection at a receiver, it is of advantage to restrict the number of valid combinations. In this case, two bits information is encoded by four valid selections, which is illustrated in Table 8. For example, a transmitter chooses (so, m₀) to transmit; when a receiver receives (so, m₀), then it knows it is [00] being transmitted, e.g. two ACKs are encoded and transmitted.

Table 8

In this embodiment, the mapping relation between the information bit and sequence combination is only for illustration, and does not exclude another mapping scheme. Compared to a conventional LTE system, the mechanism of this embodiment would transmit four bits information in total. What's more, one selected valid sequence pair is modulated, multiplexed and transmitted on one antenna, which is compatible with the conventional LTE scheme.

Embodiment 5:

Another embodiment of the present disclosure will now be described with reference to Table 9 showing an encoding scheme for transmitting information in a wireless communication system, and Figure 8 showing a transmitter thereof.

Given a data sequence set with two sequences (So, S-i) and a DRS sequence set with two sequences (mo, m-i) available for one UE, the available two sets of sequences may be obtained implicitly or explicitly. Two data sequences and two DRS sequences are selected from the corresponding sets and then associated. Each of the selected DRS sequence defines one antenna, and one of the selected data sequence is associated with and used on the antenna. If the selected two data sequences (s,, Sj) are further modulated by one data symbol with QPSK modulation and transmitted in the form of Spatial Orthogonal Resource Transmit Diversity (SORTD), three bits information in total would be encoded and transmitted.

010 [(Si , mo), (So, mi )] -1

01 1 [(So, mo), (Si , mi )] -j

100 [(so, m₀), (si, mi )] -1

101 [(Si , m₀), (So, mi )] j

1 10 [(so, m₀), (si, mi )] j

1 1 1 [(Si , m₀), (So, mi )] -j

Table 9

Refer to Figure 8, two data sequence Sj, Sj (0<i, j<2) and two DRS sequence rrij (0<j<2) are chosen and associated for encoding information, and they are transmitted on two antennas, where each DRS sequence defines one antenna or antenna port, furthermore s,, Sj (0<i, j<0) being modulated by an ACK/NACK symbol, i.e. QPSK, to convey two bits information. For example, the transmitter chooses [(so, mo), (si , mi)] and a=1 to transmit; when a receiver receives a=1 , and [(so, m₀), (si, mi)], then it knows it is [000] being transmitted, e.g. three ACKs are encoded and transmitted.

In this embodiment, the mapping relation between the information bit and sequence combination is only for illustration, and does not exclude another mapping scheme. Compared to a conventional LTE system, the mechanism of this embodiment would transmit three information bits [bo bi b₂] in total while achieving transmission diversity gain due to SORTD. What's more, one of the selected sequence pair is modulated, multiplexed and transmitted on one antenna, which is compatible with the conventional LTE scheme.

One variation of this embodiment is: if there are two data symbols with QPSK modulation transmitted in the form of SORSM and each modulation symbol is transmitted by one data sequence, five information bits [bo bi b₂ b3 b₄] in total would be encoded and transmitted, e.g. five ACKs/NACKs in total would be encoded and transmitted as shown in Figure 9.

Another variation of this embodiment is: a different encoding scheme is used here. Among the three information bits [bo bi b₂], bo is used to corresponds to sequence combination is used; and [bi b₂] are used for QPSK modulation; and the related transmitter is shown in Figure 10.

Embodiment 6: Another embodiment of the present disclosure will now be described with reference to Table 10 showing an encoding scheme for transmitting information in a wireless communication system.

Given a data sequence set with two sequences (So, S-i ) and a DRS sequence set with two sequences (mo, m-i ) available for one UE, the available two sets of sequences may be obtained implicitly or explicitly. One sequence is selected from the data sequences and modulated by one QPSK symbol, and one sequence is selected from the DRS sequences. The UE associates one selected data sequence with one selected DRS sequence for encoding transmission. Four bits information in total would be encoded and transmitted, e.g. four ACKs/NACKs in total would be encoded and transmitted.

Table 10

In this embodiment, the mapping relation between the information bit and sequence combination is only for illustration, and does not exclude another mapping scheme. Compared to a conventional LTE system, the mechanism of this embodiment would transmit four information bits [bo bi b2 bs] in total, e.g. four ACKs/NACKs are transmitted in this embodiment.

Embodiment 7:

In case of CQI transmission, there are 14 symbols in a subframe in which there are 4 symbols for DRS transmission and the remaining 10 symbols for data transmission. Given a data sequence set with two sequences (So, S-i ) and a DRS set with two sequences (rrio, m-i ) available for one UE, and there are two antennas for CQI transmission. Two DRS sequences (m₀, m-i ) are selected to define two antenna ports or associate with two antennas, and two data sequences are selected. During each symbol for data transmission, the two data sequences are modulated by a QPSK symbol and transmitted in the form of SORTD, wherein the two data sequences would have different association with the two defined antenna ports to encode 1 bit information. Hence 3 bits information in total, including 2 bits information encoded by QPSK modulation and 1 bit information encoded by sequence association, would be encoded and transmitted on each data symbol . In total 30 bits CQI information would be transmitted in a subframe in which there are 10 symbols for data transmission. An exemplary encoding scheme on each data symbol is shown in Table 1 1 .

Table 1 1

Furthermore, in another embodiment of this invention, after obtaining the indices of data and DRS sequences via sequence selection and sequence association, sequence hopping based on the selected data and/or DRS sequence could be used over different SC-FDMA symbols to randomize inter-cell interference. For example, one data sequence S, is selected to be transmitted over three SC- FDMA symbols in a cell. And a data sequence hopping pattern [S,, Si+i , Si+2] is predefined for this cell, then S, will be transmitted over the first SC-FDMA symbol, Si+i will be transmitted over the second SC-FDMA symbol, and S,+2 will be transmitted over the last SC-FDMA symbol. If the same data sequence S, is selected to be transmitted over three SC-FDMA symbols in an adjacent cell. A randomized data sequence hopping pattern [S,, S_i+3, S_i+5] may be predefined for this adjacent cell, which means S, will be transmitted over the first SC-FDMA symbol, Si+3 will be transmitted over the second SC-FDMA symbol, and Si₊₅ will be transmitted over the last SC-FDMA symbol. In this way, inter-cell interference is randomized. The sequence hopping pattern for each cell is predefined, i.e. both eNB and UEs know which data and/or DRS sequence to be used over each SC-FDMA symbol according to the selected data and/or sequence and the corresponding hopping pattern.

Another exemplary embodiment:

Refer to Figure 1 1 ; an exemplary embodiment of this disclosure is illustrated. A wireless communication system 1 101 includes a receiver 1 102 in communication with a transmitter 1 103 comprising at least one antenna port or antenna.

The transmitter 1 103 comprises:

a unit 1 1031 , adapted to determine a set of M first type sequences and a set of N second type sequences, wherein M and N are positive integers, and M+N>2; a unit 1 1032, adapted to select K sequences from the set of first type sequences, wherein K is a positive integer, K ^ 1 , and each selected sequence defines one antenna or antenna port;

a unit 1 1033, adapted to select J sequences, irrespective of the K selected sequences, from the set of second type sequences, wherein J is a positive integer, and K=¾J; and

a unit 1 1034, adapted to associate the J selected sequences with the K defined antennas or antenna ports, wherein each selected second type sequence associates with only one antenna or antenna port, each antenna or antenna port being associated with at least one selected second type sequence, and a number of information bits are encoded by the units of sequence selection and the unit of sequence association

At least one pair of sequences may be formed by the sequence association, wherein each sequence pair of the at least one pair of sequences comprises one first type sequence and one second type sequence.

The transmitter may further comprise a unit 1 1035, adapted to perform simultaneous transmission of the selected sequences.

The receiver 1 102 comprises:

a unit 1 1021 , adapted to receive at least one of the first type sequences and at least one of the second type sequences transmitted by the transmitter;

a unit 1 1022, adapted to estimate a channel based on received first type sequences; and

a unit 1 1023, adapted to demodulate the information encoded by the transmitter based on the estimated channel and the received second type seqeunces.

The transmitter may be a UE. The receiver may be an eNB. The wireless communication system may be an LTE-A system.

Another exemplary embodiment:

Refer to Figure 12, an exemplary non-transitory computer-readable storage medium 1201 with an executable program 1202 stored thereon is illustrated. The program 1202 instructs a microprocessor 1203 to perform the following steps:

determining, by a transmitter of the wireless communication system, a set of M first type sequences and a set of N second type sequences, wherein M and N are positive integers, and M+N>2;

selecting, by the transmitter, K sequences from the set of first type sequences, wherein K is a positive integer, K ^ 1 , and each selected sequence defines one antenna or antenna port;

selecting, by the transmitter, J sequences, irrespective of the K selected sequences, from the set of second type sequences, wherein J is a positive integer, and K=¾J;

associating, by the transmitter, the J selected sequences with the K defined antennas or antenna ports, wherein each selected second type sequence associates with only one antenna or antenna port, each antenna or antenna port being associated with at least one selected second type sequence, a number of information bits are encoded by the sequence selection of K and J sequences and the sequence association.

The transmitter may be a UE. The wireless communication system may be an LTE-A system.

Another exemplary embodiment:

Refer to Figure 13; an exemplary embodiment of this disclosure is illustrated. The chip 1300 used in a transmitter of a wireless communication system comprises: a function unit 1301 , adapted to determine a set of M first type sequences and a set of N second type sequences, wherein M and N are positive integers, and M+N>2;

a function unit 1302, adapted to select K sequences from the set of first type sequences, wherein K is a positive integer, K ^ 1 , and each selected sequence defines one antenna or antenna port;

a function unit 1303, adapted to select J sequences, irrespective of the K selected sequences, from the set of second type sequences, wherein J is a positive integer, and K=¾J; and

a function unit 1304, adapted to associate the J selected sequences with the K defined antennas or antenna ports, wherein each selected second type sequence associates with only one antenna or antenna port, each antenna or antenna port associates with at least one selected second type sequence, and a number of information bits are encoded by the function units of sequence selection and the function unit of sequence association.

The chip may further comprise a function unit 1305, adapted to perform simultaneous transmission of the selected sequences.

The chip may be an ASIC used in a UE. The wireless communication system may be an LTE-A system. Although the features and elements of the present invention are described in the exemplary embodiments in particular combinations, each feature or element can be used alone without the other features and elements of the preferred embodiments or in various combinations with or without other features and elements of the present invention. The methods of flow charts provided in the present invention may be implemented in a computer program, software, or firmware tangible embodied in a computer-readable storage medium for execution by a general purpose computer or a processor. Examples of computer-readable storage mediums include a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs).

Suitable processors include, by way of example, a general purpose processor, a special processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), and/or a state machine.

A processor in association with software may be used to implement a radio frequency transceiver for use in a mobile station (MS), user equipment (UE), terminal, base station, radio network controller (RNC), or any host computer. The MS may be used in conjunction with modules, implemented in hardware and/or software, such as a camera, a video camera module, a videophone, a speakerphone, a vibration device, a speaker, a microphone, a television transceiver, a hands free headset, a keyboard, a Bluetooth® module, a frequency modulated(FM) radio unit, a liquid crystal display (LCD) display unit, an organic light-emitting diode (OLED) display unit, a digital music player, a media player, a video game player module, an Internet browser, and/or wireless local area network (WLAN) module.

It will be understood that the invention is not restricted to the aforedescribed and illustrated exemplifying embodiments thereof and that modifications can be made within the scope of the inventive concept as illustrated in the accompanying Claims.

Claims

1 . A method of information encoding at a transmitter in a wireless communication system, comprising:

determination of a set of M first type sequences and a set of N second type sequences, wherein M and N are positive integers, and M+N>2;

selectionof K sequences from said set of first type sequences, wherein K is a positive integer, K^ 1 , and each selected sequence defines one antenna or antenna port;

selection of J sequences, irrespective of said K selected sequences, from said set of second type sequences, wherein J is a positive integer, and K=¾J;

association of said J selected sequences with said K defined antennas or antenna ports, wherein each selected second type sequence associates with only one antenna or antenna port, each antenna or antenna port being associated with at least one selected second type sequence, wherein a number of information bits are encoded by said sequence selection of K and J sequences and said sequence association.

2. The method according to claim 1 , wherein K=J, and the J selected second type sequences are permutated and associated with the K selected first type sequences.

3. The method according to claim 1 , comprising:

forming at least one pair of sequences by said sequence association, wherein each sequence pair of said at least one pair of sequences comprises one first type sequence and one second type sequence.

4. The method according to claim 3, wherein said information is encoded by one or more valid pairs of sequences of said at least one pair of sequences.

5. The method of claim 1 , wherein said information comprises uplink control information, and said uplink control information comprises one or any combination of the following: ACK/NACK, Channel Quality Indicator, Scheduling Request, or Channel State Information.

6. The method according to claim 1 , wherein said transmitter is a UE, and said wireless communication system is a LTE-A system.

7. The method according to any of claims 1 to 6, wherein said first set of sequence is a set of Demodulation Reference Signal, DRS, sequences, said second set of sequences is a set of data sequences, each of said selected data sequence is modulated by a modulation symbol, and said modulation symbol is any of BPSK, QPSK, 8PSK, 16QAM.

8. The method according to claim 7, wherein said set of data sequences and said set of Demodulation Reference Signal sequences are allocated to said transmitter, and said transmitter performs simultaneous transmission of said selected sequences in the form of Spatial Orthogonal Resource Transmit Diversity, SORTD, or Spatial Orthogonal Resource Spatial Multiplexing, SORSM.

9. The method according to claim 7, wherein said a number of information bits are jointly encoded or separately encoded by said two types sequence selection, said sequence association and said modulation symbol.

10. The method according to claim 7, wherein sequence hopping based on the selected data and/or DRS sequence is employed.

1 1 . The method according to claim 7, wherein said set of data sequences and said set of Demodulation Reference Signal sequences are implicitly allocated by the Control Channel Elements, CCEs, of Physical Downlink Control Channel, PDCCH.

12. The method according to claim 7, wherein said set of data sequences and said set of Demodulation Reference Signal sequences are explicitly allocated by Radio Resource Control, RRC, signalling.

13. The method according to claim 7, wherein the DRS sequence is used by a receiver to estimate a channel which is used for demodulation of the control information.

14. The method according to 7, wherein said set of DRS sequences contains at least two sequences.

15. A transmitter comprising at least one antenna port or antenna in a wireless communication system, comprising:

a unit, adapted to determine a set of M first type sequences and a set of N second type sequences, wherein M and N are positive integers, and M+N>2;

a unit, adapted to select a number, K, of sequences from said set of first type sequences, wherein K is a positive integer, K ^ 1 , and each selected sequence defines one antenna or antenna port;

a unit, adapted to select a number, J, of sequences, irrespective of said K selected sequences, from said set of second type sequences, wherein J is a positive integer, and K=¾J; and a unit, adapted to associate said J selected sequences with said K defined antennas or antenna ports,

wherein each selected second type sequence associates with only one antenna or antenna port, each antenna or antenna port associates with at least one selected second type sequence, and a number of information bits are encoded by said units of sequence selection and said unit of sequence association.

16. The transmitter according to claim 15, wherein at least one pair of sequences is formed by said sequence association, and each sequence pair of said at least one pair of sequences comprises one first type sequence and one second type sequence.

17. The transmitter according to claim 16, wherein said information is encoded by one or more valid pairs of sequences of said at least one pair of sequences.

18. The transmitter according to 15, wherein said first set of sequence is a set of data sequences; and said second set of sequences is a set of Demodulation Reference Signal, DRS, sequences.

19. The transmitter according to claim 18, wherein sequence hopping based on the selected data and/or DRS sequence is employed.

20. The transmitter according to claim 18, wherein said set of data sequences and said set of Demodulation Reference Signal sequences are allocated to said transmitter, and said transmitter comprises a unit adapted to perform simultaneous transmission of said selected sequences.

21 . The transmitter according to 15, wherein said transmitter is a UE, and said wireless communication system is a LTE-A system.

22. A wireless communication system comprising at least one receiver which is in communication with the transmitter according to any of claims 15 to 21 , wherein said receiver comprises:

a unit, adapted to receive at least one of said first type sequences and at least one of said second type sequences transmitted by said transmitter;

a unit, adapted to estimate a channel based on said received first type sequences; and

a unit, adapted to demodulate the information encoded by said transmitter based on said estimated channel and said received second type sequences.

23. A non-transitory computer-readable storage medium with an executable program stored thereon, wherein the program instructs a microprocessor to perform the steps of any of claims 1 to 14.

24. A chip used in a transmitter of a wireless communication system, comprising: a function unit, adapted to determine a set of M first type sequences and a set of N second type sequences, wherein M and N are positive integers, and M+N>2; a function unit, adapted to select K sequences from said set of first type sequences, wherein K is a positive integer, K ^ 1 , and each selected sequence defines one antenna or antenna port;

a function unit, adapted to select J sequences, irrespective of said K selected sequences, from said set of second type sequences, wherein J is a positive integer, and K=¾J; and

a function unit, adapted to associate said J selected sequences with said K defined antennas or antenna ports, wherein each selected second type sequence associates with only one antenna or antenna port, each antenna or antenna port associates with at least one selected second type sequence, and a number of information bits are encoded by said function units of sequence selection and said function unit of sequence association.

25. The chip according to claim 24, wherein at least one pair of sequences is formed by said sequence association, and each sequence pair of said at least one pair of sequences comprises one first type sequence and one second type sequence.

26. The chip according to claim 24, comprising:

a function unit, adapted to perform simultaneous transmission of said selected sequences.