SIGNAL DETECTING METHOD AND DEVICE

• US 20170170928A1
• Filed: 10/23/2016
• Published: 06/15/2017
• Est. Priority Date: 12/14/2015
• Status: Active Grant

• Current Assignee: Tsinghua University
• Original Assignee: Tsinghua University
• Inventors: LIU, Leibo, PENG, Guiqiang, XUE, Yang, YIN, Shouyi, WEI, Shaojun, ZHANG, Peng
• Granted Patent: US 9,729,277 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 17/26 using historical data, averaging values or statistics
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
• CPC Class Codes: H04B 7/04 using two or more spaced independent antennas
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04L 1/005 Iterative decoding, including iteration between signal detection and decoding operation
• CPC Class Codes: H04L 1/02 by diversity reception
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04W 52/225 Calculation of statistics, e.g. average, variance
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A signal detecting method and device are disclosed. The method includes: obtaining a matched filtering signal; determining a filtering matrix; decomposing the filtering matrix to obtain a principal diagonal matrix and a non-principal diagonal matrix; obtaining a parameter matrix and a parameter vector according to the principal diagonal matrix, the non-principal diagonal matrix, and the matched filtering signal; obtaining an iterative parameter and an iterative initial value according to the parameter matrix and the parameter vector; and performing an iterative calculation according to the iterative parameter and the iterative initial value; if the number of iterations reaches a preset number, obtaining an iterative final value, and obtaining an input of a decoder according to the iterative final value. The signal detection method may reduce the computational complexity and bit error rate, improve data throughput, and more advantageous for use in a large-scale multi-input multi-output system.

Claims

1. A signal detecting method, applied to a base station which is configured to receive an encoded signal, and comprising:

obtaining a matched filtering signal;

determining a filtering matrix used when obtaining the matched filtering signal;

decomposing the filtering matrix to obtain a principal diagonal matrix and a non-principal diagonal matrix;

obtaining a parameter matrix and a parameter vector for an iterative calculation according to the principal diagonal matrix, the non-principal diagonal matrix, and the matched filtering signal;

obtaining an iterative parameter and an iterative initial value according to the parameter matrix and the parameter vector; and

performing the iterative calculation according to the iterative parameter and the iterative initial value;

if the number of iterations reaches a preset number, obtaining an iterative final value, and. obtaining an input of a decoder according to the iterative final value, so as to decode the encoded signal and to realize the signal detecting.

2. The signal detecting method according to claim 1, wherein, obtaining a matched filtering signal comprises:

obtaining the matched filtering signal by a formula of

y^MF=H^Hy,

where, y is the encoded signal which is a signal via a channel received by an antenna array of the base station, y^MF is the matched filtering signal, H is a channel matrix, and H^H is a conjugate transpose matrix of the channel matrix H.

3. The signal detecting method according to claim 1, wherein the filtering matrix is obtained by a formula of

A=H^HH+N₀E_s⁻

1I_M,

where, A is the filtering matrix, H is a channel matrix, H^H is a conjugate transpose matrix of the channel matrix H, N₀ is a noise power spectrum density, E_s is an average power for each transmission signal, E_s<sup>−

1</sup> is a reciprocal value of the average power for each transmission signal, I_M is a unit matrix, and M is the number of antennas in the antenna array of the base station.

4. The signal detecting method according to claim 1, wherein, obtaining a parameter matrix and a parameter vector for an iterative calculation according to the principal diagonal matrix, the non-principal diagonal matrix, and the matched filtering signal comprises:

obtaining the parameter matrix according to the principal diagonal matrix and the non-principal diagonal matrix by a formula of

R=P<sup>−

1</sup>Q,

where, R is the parameter matrix, P is the principal diagonal matrix, P<sup>−

1</sup> is an inverse matrix of the principal diagonal matrix, and Q is the non-principal diagonal matrix;

obtaining the parameter vector according to the principal diagonal matrix and the matched filtering signal by a formula of

T=P<sup>−

1</sup>y^MF,

where, T is the parameter vector, and y^MF is the matched filtering signal.

5. The signal detecting method according to claim 1, wherein, the iterative parameters comprise an iterative coefficient matrix and an iterative constant matrix;

and obtaining an iterative parameter and an iterative initial value according to the parameter matrix and the parameter vector, comprises;

obtaining the iterative coefficient matrix according to a time relaxation parameter and the parameter matrix by a formula of

B=(1ω

)I-ω

R,

where, B is the iterative coefficient matrix, ω

is the time relaxation parameter, and I is a unit matrix, R is the parameter matrix;

obtaining the iterative constant matrix according to the time relaxation parameter and the parameter vector by a formula of

F=ω

T,

where, F is the iterative constant matrix, T is the parameter vector; and

obtaining the iterative initial value according to the parameter matrix and the parameter vector by a formula of

ŝ

(0)=(I-R)T,

where, ŝ

(0) is the iterative initial value.

6. The signal detecting method according to claim 5, wherein, performing the iterative calculation according to the iterative parameter and the iterative initial value, comprises:

performing the iterative calculation by a formula of

ŝ

(k)=Bŝ

(k-1)+F,

where, k is the nut of iterations, and k is a positive integer equal to or greater than 1.

7. The signal detecting method according to claim 1, wherein, wherein obtaining an input of a decoder according to the iterative final value comprises:

obtaining a computation signal according to the iterative final value and principal diagonal elements of an effective channel gain matrix by a formula of

8. The signal detecting method according to claim 7, wherein the principal diagonal elements of the effective channel gain matrix are obtained according to the principal diagonal matrix and a channel Gram matrix by a formula of

U_ii=(P⁻

1G)_ii

where, U_ii indicates i^th principal diagonal element of the effective channel gain matrix;

wherein the channel Gram matrix is obtained according to the channel matrix by a formula of

G=HH^H,

where, G is the channel Gram matrix, H is a channel matrix, and H^H is a conjugate transpose matrix of the channel matrix H.

9. A signal detecting device, applied to a base station which is configured to receive an encoded signal, comprising:

a matrix and matched filtering calculating circuit, configured to calculate a matched filtering signal, a channel Gram matrix and a filtering matrix;

a pre-processing circuit, configured to calculate a parameter matrix and a parameter vector for an iterative calculation and principal diagonal elements of an effective channel gain matrix according to the filtering matrix, the matched filtering signal and the channel Gram matrix;

an iterative circuit, configured to obtain an iterative parameter and an iterative initial value according to the parameter matrix and the parameter vector, and to perform the iterative calculation according to the iterative parameter and the iterative initial value, and to obtain an iterative final value if the number of iterations reaches a preset number; and

a maximum log likelihood rate calculating circuit, configured to obtain a maximum log likelihood rate according to the iterative final value and the principal diagonal elements of the effective channel gain matrix, and to input the maximum log likelihood rate to a decoder so as to decode the encoded signal and to realize the signal detecting.

10. The signal detecting device according to claim 9, wherein, the matrix and matched filtering calculating circuit, the pre-processing circuit, the iterative circuit, and the maximum log likelihood rate calculating circuit respectively comprises at least one of a first processing unit, a second processing unit, a third processing unit, a fourth processing unit, a fifth processing unit and a sixth processing unit.

11. The signal detecting device according to claim 10, wherein, the first processing unit comprises:

4 first arithmetic logic unit arrays with the same structure, in which each of the first arithmetic logic unit arrays comprises;

3 arithmetic logic units, 2 accumulators, 1 register and 1 reciprocal unit, wherein,

an output end of a first arithmetic logic unit and an output end of a second arithmetic logic unit are connected to an input end of a. ^-first accumulator, an output end of the first accumulator is connected to the register;

an output end of a third arithmetic logic unit is connected to an input end of a second accumulator, and an output end of the second accumulator is connected to the reciprocal unit,

12. The signal detecting device according to claim 10, wherein, the second processing unit comprises:

4 second arithmetic logic unit arrays with the same structure, in which each of the second arithmetic logic unit arrays comprises;

2 arithmetic logic units and 1 accumulator, wherein,

an output end of a fourth arithmetic logic unit and an output end of a fifth arithmetic logic unit are connected to an input end of the accumulator.

13. The signal detecting device according to claim 10, wherein, the third processing unit comprises:

4 conjugate complex module arrays with the same structure.

14. The signal detecting device according to claim 10, wherein, the fourth processing unit comprises:

2 arithmetic logic units and a real-plural converting unit, wherein,

an output end of a sixth arithmetic logic unit and an output end of a seventh arithmetic logic unit are respectively connected to an input end of the real-plural converting unit.

15. The signal detecting device according to claim 10, wherein, the fifth processing unit comprises:

2 arithmetic logic units, 2 accumulators and 1 real-plural converting unit, wherein the arithmetic logic units and the accumulators are in a one-to-one connection, an output end of a third accumulator and an output end of a fourth accumulator are connected to an input end of the real-plural converting unit.

16. The signal detecting device according to claim 10, wherein, the sixth processing unit comprises:

3 arithmetic logic units, a lookup table and a reciprocal unit,

an output end of the lookup table is connected to an input end of an eighth arithmetic logic unit, an output end of the reciprocal unit is connected to an input end of an ninth arithmetic logic unit, and an output end of the eighth arithmetic logic unit and an output end of the ninth arithmetic logic unit are connected to an input end of a tenth arithmetic logic unit.

17. The signal detecting device according to claim 10, wherein, the matrix and matched filtering calculating circuit comprises a unilateral input diagonal base pulse calculation array which includes a plurality of the first processing units, a plurality of the second processing units, and a plurality of the third processing units, in which, inputs end of the unilateral input diagonal base pulse calculation array comprise the plurality of the first processing units, a diagonal base pulse on the unilateral input diagonal base pulse calculation array comprises the plurality of the third processing units, and the rest are the second processing units, wherein,

the first processing units are configured to calculate the matched filtering signal by a formula of y^MF=H^Hy, principal diagonal elements of the channel Gram matrix and a reciprocal value of the channel Gram matrix, where y^MF indicates the matched filtering signal, H indicates the channel matrix, H^H indicates a conjugate transpose matrix of the channel matrix, and y indicates the encoded signal which is a signal via a channel received by an antenna array of the base station;

the second processing units are configured to calculate the non-principal diagonal matrix of the filtering matrix, wherein the filtering matrix is obtained by a formula of

A=H^HH+N₀E_s<sup>−

1</sup>I_M,

where, A is the filtering matrix, N₀ is a noise power spectral density, E_s is an average power for each transmission signal, E_s<sup>−

1</sup> is a reciprocal value of the average power for each transmission signal, I_M is a unit matrix, and M is the number of antennas in the antenna array of the base station; and

the third processing units are configured to calculate a conjugate complex matrix of a complex matrix.

18. The signal detecting device according to claim 11, wherein, the pre-processing circuit is formed by parallelly connecting serially connected M-1 fourth processing units with one fourth processing unit, M denotes the size of the effective channel gain matrix, the fourth processing units are configured to calculate R=P⁻

1Q, U_ii=(P<sup>−

1</sup>G)_ii and T=P<sup>−

1</sup>y^MF, where, R is the parameter matrix, P is the principal diagonal matrix, P<sup>−

1</sup> is an inverse matrix of the principal diagonal matrix, Q is the non-principal diagonal matrix, U_ii indicates the i^th principal diagonal elements of the effective channel gain matrix, G is the channel Gram matrix, H is the channel matrix, T is the parameter vector, and is the matched filtering signal.

19. The signal detecting device according to claim 11, wherein, the iterative circuit is formed by serially connecting M fifth processing units, and the fifth processing units are configured to calculate an iterative initial value by a formula of ŝ

(0)=(I-R)T and to finish the final iterative calculation by a formula of ŝ

(k)=Bŝ

(k-1)+F, where, ŝ

(0) is the iterative initial value, I is a unit matrix, R is the parameter matrix, T is the parameter vector, B is an iterative coefficient matrix, F is an iterative constant matrix, k is the number of iterations, and k is a positive integer equal to or greater than 1,

20. The signal detecting device according to claim 11, wherein, the maximum log likelihood rate calculating circuit is formed by 3 sixth processing units, and the sixth processing units are configured to calculate a computation signal according to the iterative final value and principal diagonal elements of an effective channel gain matrix by a formula of