Method and apparatus for resource mapping and code division multiplexing

• US 9,166,720 B2
• Filed: 12/03/2013
• Issued: 10/20/2015
• Est. Priority Date: 01/08/2010
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Sun, Weijun, Zhou, Yongxing
• Primary Examiner(s): Harper, Kevin C
• Application Number:
  US14/095,656
• Publication Number:
  US 20140092874A1
• Time in Patent Office: 686 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H04J 13/0003 Code application, i.e. aspects relating to how codes are applied to form multiplexed channels
• CPC Class Codes: H04J 13/18 Allocation of orthogonal codes
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 27/262 Reduction thereof by selection of pilot symbols
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/0073 Allocation arrangements that take into account other cell interferences for intercell interference mitigation or co-ordination in orthogonal multiplex systems H04J11/005
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA

Abstract

The present disclosure discloses a method and an apparatus for resource mapping and code division multiplexing. In the present disclosure, each cell selects a mapping scheme among at least two mapping schemes to implement resource mapping, which effectively reduces interference imposed on reference signal symbols of users at the edge of a cell; vector switching is performed for an orthogonal matrix to obtain multiple different codeword sequences and implement codeword design, so that a problem that the output power of reference signal symbols is unbalanced can be effectively alleviated.

Claims

1. A reference signal transmission method in a wireless telecommunication system, comprising:

for a plurality of codeword sequences and a plurality of reference signal sub-carriers in a resource block, determining a mapping relationship between each codeword sequence and a reference signal sub-carrier;

multiplexing, on each of the reference signal sub-carriers, reference signal symbols of multiple space layers in the resource block according to the codeword sequence corresponding to the reference signal sub-carrier; and

transmitting the multiplexed reference signal symbols of the space layers;

wherein each codeword sequence comprises a codeword A, a codeword B, a codeword C and a codeword D, arranged in an arranging order, and arranging orders of the codeword A, the codeword B, the codeword C and the codeword D in the codeword sequences are different from each other.

2. The method according to claim 1, wherein the codeword sequences comprise a codeword sequence W1, a codeword sequence W2, a codeword sequence W3 and a codeword sequence W4, and wherein

the arranging order of the codewords in the codeword sequence W1 is A-B-C-D;

the arranging order of the codewords in the codeword sequence W2 is B-A-D-C;

the arranging order of the codewords in the codeword sequence W3 is C-D-A-B or C-D-B-A; and

the arranging order of the codewords in the codeword sequence W4 is D-C-B-A or D-C-A-B.

3. The method according to claim 2, wherein

the codeword A is a column vector [1, 1, 1, 1]^T or a row vector [1, 1, 1, 1],

the codeword B is a column vector [1, −

1, 1, −

1]^T or a row vector [1, −

1, 1, −

1],

the codeword C is a column vector [1, 1, −

1, −

1]^T or a row vector [1, 1, −

1, −

1], and

the codeword D is a column vector [1, −

1, −

1, 1]^T or a row vector [1, −

1, −

1, 1].

4. The method according to claim 3, wherein the reference signal symbols of each space layer in the resource block are orthogonal frequency division multiplexing (OFDM) symbols 6, 7, 13, and 14, and wherein

the OFDM symbol 6 of the space layers in the resource block are multiplexed according to a first codeword in the arranging order of the codeword sequence corresponding to the reference signal sub-carrier;

the OFDM symbol 7 of the space layers in the resource block are multiplexed according to a second codeword in the arranging order of the codeword sequence corresponding to the reference signal sub-carrier;

the OFDM symbol 13 of the space layers in the resource block are multiplexed according to a third codeword in the arranging order of the codeword sequence corresponding to the reference signal sub-carrier;

the OFDM symbol 14 of the space layers in the resource block are multiplexed according to a fourth codeword in the arranging order of the codeword sequence corresponding to the reference signal sub-carrier.

5. The method according to claim 2, wherein codeword sequences W1, W2, W3 and W4 are in form of matrixes, and

W1=[A, B, C, D];

W2=[B, A, D, C];

W3=[C, D, A, B] or [C, D, B, A]; and

W4=[D, C, B, A] or [D, C, A, B];

wherein A, B, C and D are column vectors.

6. The method according to claim 2, wherein codeword sequences W1 , W2, W3 and W4 are in form of matrixes, and

7. The method according to claim 2, wherein the codeword sequences W1, W2, W3, and W4 respectively correspond, by turns, to each of the reference signal sub-carriers.

8. A reference signal transmission apparatus in a wireless telecommunication system, comprising:

a processor, configured to, for a plurality of codeword sequences and a plurality of reference signal sub-carriers in a resource block, determine a mapping relationship between each codeword sequence and a reference signal sub-carrier; and

multiplex, on each of the reference signal sub-carriers, reference signal symbols of multiple space layers in the resource block according to the codeword sequence corresponding to the reference signal sub-carrier; and

a transmitter, configured to transmit the multiplexed reference signal symbols of the space layers;

wherein each codeword sequence comprises a codeword A, a codeword B, a codeword C and a codeword D, arranged in an arranging order, and arranging orders of the codeword A, the codeword B, the codeword C and the codeword D in the codeword sequences are different from each other.

9. The apparatus according to claim 8, wherein the codeword sequences comprise a codeword sequence W1, a codeword sequence W2, a codeword sequence W3 and a codeword sequence W4;

and

the arranging order of the codewords in the codeword sequence W1 is A-B-C-D;

the arranging order of the codewords in the codeword sequence W2 is B-A-D-C;

the arranging order of the codewords in the codeword sequence W3 is C-D-A-B or C-D-B-A; and

the arranging order of the codewords in the codeword sequence W4 is D-C-B-A or D-C-A-B.

10. The apparatus according to claim 9, wherein

the codeword A is a column vector [1, 1, 1, 1]^T or a row vector [1, 1, 1, 1],

the codeword B is a column vector [1, −

1, 1, −

1]^T or a row vector [1, −

1, 1, −

1],

the codeword C is a column vector [1, 1, −

1, −

1]^T or a row vector [1, 1, −

1, −

1], and

the codeword D is a column vector [1, −

1, −

1, 1]^T or a row vector [1, −

1, −

1, 1].

11. The apparatus according to claim 10, wherein the reference signal symbols of each space layer in the resource block are orthogonal frequency division multiplexing (OFDM) symbols 6, 7, 13, and 14, and wherein

the OFDM symbol 6 of the space layers in the resource block are multiplexed according to a first codeword in the arranging order of the codeword sequence corresponding to the reference signal sub-carrier;

the OFDM symbol 7 of the space layers in the resource block are multiplexed according to a second codeword in the arranging order of the codeword sequence corresponding to the reference signal sub-carrier;

the OFDM symbol 13 of the space layers in the resource block are multiplexed according to a third codeword in the arranging order of the codeword sequence corresponding to the reference signal sub-carrier;

the OFDM symbol 14 of the space layers in the resource block are multiplexed according to a fourth codeword in the arranging order of the codeword sequence corresponding to the reference signal sub-carrier.

12. The apparatus according to claim 9, wherein codeword sequences W1, W2, W3 and W4 are in form of matrixes, and

W1=[A, B, C, D];

W2=[B, A, D, C];

W3=[C, D, A, B] or [C, D, B, A]; and

W4=[D, C, B, A] or [D, C, A, B];

wherein A, B, C and D are column vectors.

13. The apparatus according to claim 9, wherein codeword sequences W1, W2, W3 and W4 are in form of matrixes, and

14. The apparatus according to claim 8, wherein the codeword sequences W1, W2, W3, and W4 respectively correspond, by turns, to each of the reference signal sub-carriers.

15. A method for obtaining a channel estimation value in a wireless telecommunication system, comprising:

receiving, by a user equipment, reference signal symbols of space layers from a signal transmitter;

obtaining, by the user equipment, a channel estimation value for demodulating user data according to the reference signal symbols;

wherein the reference signal symbols of multiple space layers were multiplexed on each of the reference signal sub-carriers in a resource block according to a codeword sequence corresponding to the reference signal sub-carrier, and the codeword sequence is among multiple codeword sequences respectively corresponding to multiple reference signal sub-carriers in the resource block; and

wherein each codeword sequence comprises a codeword A, a codeword B, a codeword C and a codeword D, arranged in an arranging order, and arranging orders of the codeword A, the codeword B, the codeword C and the codeword D in the codeword sequences are different from each other.

16. The method according to claim 15, wherein the codeword sequences comprise a codeword sequence W1, a codeword sequence W2, a codeword sequence W3 and a codeword sequence W4;

and wherein

the arranging order of the codewords in the codeword sequence W1 is A-B-C-D;

the arranging order of the codewords in the codeword sequence W2 is B-A-D-C;

the arranging order of the codewords in the codeword sequence W3 is C-D-A-B or C-D-B-A; and

the arranging order of the codewords in the codeword sequence W4 is D-C-B-A or D-C-A-B.

17. The method according to claim 16, wherein

the codeword A is a column vector [1, 1, 1, 1]^T or a row vector [1, 1, 1, 1],

the codeword B is a column vector [1, −

1, 1, −

1]^T or a row vector [1, −

1, 1, −

1],

the codeword C is a column vector [1, 1, −

1, −

1]^T or a row vector [1, 1, −

1, −

1], and

the codeword D is a column vector [1, −

1, −

1, 1]^T or a row vector [1, −

1, −

1, 1].

18. The method according to claim 17, wherein the reference signal symbols of each space layer in the resource block are orthogonal frequency division multiplexing (OFDM) symbols 6, 7, 13, and 14, and wherein

the OFDM symbol 6 of the space layers in the resource block are multiplexed according to a first codeword in the arranging order of the codeword sequence corresponding to the reference signal sub-carrier;

the OFDM symbol 7 of the space layers in the resource block are multiplexed according to a second codeword in the arranging order of the codeword sequence corresponding to the reference signal sub-carrier;

the OFDM symbol 13 of the space layers in the resource block are multiplexed according to a third codeword in the arranging order of the codeword sequence corresponding to the reference signal sub-carrier;

the OFDM symbol 14 of the space layers in the resource block are multiplexed according to a fourth codeword in the arranging order of the codeword sequence corresponding to the reference signal sub-carrier.

19. The method according to claim 16, wherein codeword sequences W1, W2, W3 and W4 are in form of matrixes, and

W1=[A, B, C, D];

W2=[B, A, D, C];

W3=[C, D, A, B] or [C, D, B, A]; and

W4=[D, C, B, A] or [D, C, A, B];

wherein A, B, C and D are column vectors.

20. The method according to claim 16, wherein codeword sequences W1, W2, W3 and W4 are in form of matrixes, and

21. The method according to claim 15, wherein the codeword sequences W1, W2, W3, and W4 respectively correspond, by turns, to each of the reference signal sub-carriers.

22. A user equipment, comprising:

a receiver, configured to receive reference signal symbols of space layers sent by a signal transmitter; and

a processor, configured to obtain a channel estimation value for demodulating user data according to the reference signal symbols;

wherein the reference signal symbols of multiple space layers were multiplexed on each of the reference signal sub-carriers in a resource block according to a codeword sequence corresponding to the reference signal sub-carrier, the codeword sequence is among multiple codeword sequences respectively corresponding to multiple reference signal sub-carriers in the resource block;

wherein each codeword sequence comprises a codeword A, a codeword B, a codeword C and a codeword D, arranged in an arranging order, and arranging orders of the codeword A, the codeword B, the codeword C and the codeword D in the codeword sequences are different from each other.

23. The user equipment according to claim 22, wherein the codeword sequences comprise a codeword sequence W1, a codeword sequence W2, a codeword sequence W3 and a codeword sequence W4;

and wherein

the arranging order of the codewords in the codeword sequence W1 is A-B-C-D;

the arranging order of the codewords in the codeword sequence W2 is B-A-D-C;

the arranging order of the codewords in the codeword sequence W3 is C-D-A-B or C-D-B-A; and

the arranging order of the codewords in the codeword sequence W4 is D-C-B-A or D-C-A-B.

24. The user equipment according to claim 23, wherein

the codeword A is a column vector [1, 1, 1, 1]^T or a row vector [1, 1, 1, 1],

the codeword B is a column vector [1, −

1, 1, −

1]^T or a row vector [1, −

1, 1, −

1],

the codeword C is a column vector [1, 1, −

1, −

1]^T or a row vector [1, 1, −

1, −

1], and

the codeword D is a column vector [1, −

1, −

1, 1]^T or a row vector [1, −

1, −

1, 1].

25. The user equipment according to claim 24, wherein the reference signal symbols of each space layer in the resource block are orthogonal frequency division multiplexing (OFDM) symbols 6, 7, 13, and 14, and wherein

the OFDM symbol 6 of the space layers in the resource block are multiplexed according to a first codeword in the arranging order of the codeword sequence corresponding to the reference signal sub-carrier;

the OFDM symbol 7 of the space layers in the resource block are multiplexed according to a second codeword in the arranging order of the codeword sequence corresponding to the reference signal sub-carrier;

the OFDM symbol 13 of the space layers in the resource block are multiplexed according to a third codeword in the arranging order of the codeword sequence corresponding to the reference signal sub-carrier;

the OFDM symbol 14 of the space layers in the resource block are multiplexed according to a fourth codeword in the arranging order of the codeword sequence corresponding to the reference signal sub-carrier.

26. The user equipment according to claim 23, wherein codeword sequences W1, W2, W3 and W4 are in form of matrixes, and

W1=[A, B, C, D];

W2=[B, A, D, C];

W3=[C, D, A, B] or [C, D, B, A]; and

W4=[D, C, B, A] or [D, C, A, B];

wherein A, B, C and D are column vectors.

27. The user equipment according to claim 23, wherein codeword sequences W1, W2, W3 and W4 are in form of matrixes, and

28. The user equipment according to claim 22, wherein the codeword sequences W1, W2, W3, and W4 respectively correspond, by turns, to each of the reference signal sub-carriers.