Method and system for processing downlink pilot signal

• US 10,020,853 B2
• Filed: 04/15/2015
• Issued: 07/10/2018
• Est. Priority Date: 07/09/2014
• Status: Active Grant

• Current Assignee: Xi'An Zhongxing New Software Co., Ltd. (ZTE Corporation)
• Original Assignee: Xi'An Zhongxing New Software Co., Ltd. (ZTE Corporation)
• Inventors: Chen, Yijian, Lu, Zhaohua, Zhao, Jing, Wang, Yuxin
• Primary Examiner(s): PHU, PHUONG M
• Application Number:
  US15/324,847
• Publication Number:
  US 20170279504A1
• Time in Patent Office: 1,182 Days
• Field of Search: 375260, 375346, 375267, 375299, 375347, 375349
• CPC Class Codes: H04B 7/0404 the mobile station comprising multiple antennas, e.g. to provide uplink diversity
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0421 utilizing implicit feedback, e.g. steered pilot signals
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04B 7/063 Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection
• CPC Class Codes: H04B 7/0695 using beam selection

Abstract

A method and system for processing a downlink pilot signal is disclosed. Herein, the method includes: a receiving end detecting downlink measurement pilot ports to obtain a received signal corresponding to each downlink measurement pilot port on each receiving antenna; performing screening on the downlink measurement pilot ports according to the received signals; calculating a receiving weight vector of each downlink measurement pilot port, and using an uplink precoding weight vector, calculated and obtained by combining the receiving weight vector with uplink and downlink operating frequencies, for data precoding; or, using N uplink precoding weight vectors, calculated and obtained by combining the receiving weight vector with uplink and downlink operating frequencies, for uplink pilot precoding, where N is the number of uplink precoding pilots transmitted, and N is an integer which is greater than or equal to 1. The above technical solution can effectively reduce pilot overhead in communication systems.

Claims

1. A method for processing a downlink pilot signal, the method comprising:

detecting, by a receiving end, downlink measurement pilot ports to obtain a received signal corresponding to each downlink measurement pilot port on each receiving antenna;

performing screening on the downlink measurement pilot ports according to the received signals;

calculating a receiving weight vector of each downlink measurement pilot port, and using an uplink precoding weight vector, calculated and obtained by combining the receiving weight vector with uplink and downlink operating frequencies, for data precoding;

or, using N uplink precoding weight vectors, calculated and obtained by combining the receiving weight vector with uplink and downlink operating frequencies, for uplink pilot precoding, where N is the number of uplink precoding pilots transmitted, and N is an integer which is greater than or equal to 1.

2. The method of claim 1, wherein:

using an uplink precoding weight vector, calculated and obtained by combining the receiving weight vector with uplink and downlink operating frequencies, for data precoding, or when N=1, using one uplink precoding weight vector, calculated and obtained by combining the receiving weight vector with uplink and downlink operating frequencies, for uplink pilot precoding comprises;

obtaining an uplink transmitting weight vector of each downlink measurement pilot port according to the uplink and downlink frequencies and the receiving weight vector of the corresponding downlink measurement pilot port;

using the one uplink precoding weight vector, obtained by weighting and combining uplink transmitting weight vectors of various downlink measurement pilot ports, for data precoding or uplink pilot precoding.

3. The method of claim 1, wherein:

each downlink measurement pilot port is formed by the same set of antennas of a transmitting end using different precoding weights for transmission.

4. The method of claim 1, wherein:

performing screening on the downlink measurement pilot ports according to the received signals comprises;

performing screening on the downlink measurement pilot ports according to the magnitude of power or signal-to-noise ratios of the received signals.

5. The method of claim 1, wherein:

using an uplink precoding weight vector, calculated and obtained by combining the receiving weight vector with uplink and downlink operating frequencies, for data precoding, or using N uplink precoding weight vectors, calculated and obtained by combining the receiving weight vector with uplink and downlink operating frequencies, for uplink pilot precoding comprises;

obtaining an uplink transmitting weight vector of the downlink measurement pilot port according to the receiving weight vector of the corresponding downlink measurement pilot port, and multiplying a ratio of an uplink operating frequency to a downlink operating frequency with a phase of the uplink transmitting weight vector.

6. The method of claim 1, wherein:

using N uplink precoding weight vectors, calculated and obtained by combining the receiving weight vector with uplink and downlink operating frequencies, for uplink pilot precoding comprises;

after calculating and obtaining the uplink precoding weight vector by combining the receiving weight vector with the uplink and downlink operating frequencies, further determining the number of uplink measurement pilots and/or an uplink measurement pilot precoding weight according to the uplink precoding weight vector and the number of the downlink measurement pilot ports;

or,

after calculating and obtaining the uplink precoding weight vector by combining the receiving weight vector with the uplink and downlink operating frequencies, further determining the number of uplink measurement pilots and/or an uplink measurement pilot precoding weight according to the uplink precoding weight vector and at least one of the following factors;

the factors comprise;

(a) a precoding weight or a beam width of a downlink beam pilot;

(b) the number of downlink transmitting antennas;

(c) the number of uplink transmitting antennas; and

(d) signal-to-noise ratios of the received signals.

7. A system for processing a downlink pilot signal applied to a receiving end, the system comprising:

a receiving module, arranged to detect downlink measurement pilot ports to obtain a received signal corresponding to each downlink measurement pilot port on each receiving antenna;

a port screening module, arranged to perform screening on the downlink measurement pilot ports according to the received signals;

a calculating module, arranged to calculate a receiving weight vector of each downlink measurement pilot port, and set an uplink precoding weight vector, calculated and obtained by combining the receiving weight vector with uplink and downlink operating frequencies, for data precoding;

or, set N uplink precoding weight vectors, calculated and obtained by combining the receiving weight vector with uplink and downlink operating frequencies, for uplink pilot precoding, where N is the number of uplink precoding pilots transmitted, and N is an integer which is greater than or equal to 1.

8. The system of claim 7, wherein:

the calculating module is arranged to set an uplink precoding weight vector, calculated and obtained by combining the receiving weight vector with uplink and downlink operating frequencies, for data precoding, or when N=1, set one uplink precoding weight vector, calculated and obtained by combining the receiving weight vector with uplink and downlink operating frequencies, for uplink pilot precoding in the following manner;

obtaining an uplink transmitting weight vector of each downlink measurement pilot port according to the uplink and downlink frequencies and the receiving weight vector of the corresponding downlink measurement pilot port;

setting the one uplink precoding weight vector, obtained by weighting and combining uplink transmitting weight vectors of various downlink measurement pilot ports, for data precoding or uplink pilot precoding.

9. The system of claim 7, wherein:

each downlink measurement pilot port is formed by the same set of antennas of a transmitting end using different precoding weights for transmission.

10. The system of claim 7, wherein:

the port screening module is arranged to perform screening on the downlink measurement pilot ports according to the received signals in the following manner;

performing screening on the downlink measurement pilot ports according to the magnitude of power or signal-to-noise ratios of the received signals.

11. The system of claim 7, wherein:

the calculating module is arranged to set an uplink precoding weight vector, calculated and obtained by combining the receiving weight vector with uplink and downlink operating frequencies, for data precoding, or set N uplink precoding weight vectors, calculated and obtained by combining the receiving weight vector with uplink and downlink operating frequencies, for uplink pilot precoding in the following manner;

obtaining an uplink transmitting weight vector of the downlink measurement pilot port according to the receiving weight vector of the corresponding downlink measurement pilot port, and multiplying a ratio of an uplink operating frequency to a downlink operating frequency with a phase of the uplink transmitting weight vector.

12. The system of claim 7, wherein:

the calculating module is arranged to set N uplink precoding weight vectors, calculated and obtained by combining the receiving weight vector with uplink and downlink operating frequencies, for uplink pilot precoding in the following manner;

after calculating and obtaining the uplink precoding weight vector by combining the receiving weight vector with the uplink and downlink operating frequencies, further determining the number of uplink measurement pilots and/or an uplink measurement pilot precoding weight according to the uplink precoding weight vector and the number of the downlink measurement pilot ports;

or,

after calculating and obtaining the uplink precoding weight vector by combining the receiving weight vector with the uplink and downlink operating frequencies, further determining the number of uplink measurement pilots and/or an uplink measurement pilot precoding weight according to the uplink precoding weight vector and at least one of the following factors;

the factors comprise;

(a) a precoding weight or a beam width of a downlink beam pilot;

(b) the number of downlink transmitting antennas;

(c) the number of uplink transmitting antennas; and

(d) signal-to-noise ratios of the received signals.

13. A non-transitory computer-readable storage medium encoded with computer-executable instructions that, when executed, cause a processing system to perform the steps of:

detecting downlink measurement pilot ports to obtain a received signal corresponding to each downlink measurement pilot port on each receiving antenna;

performing screening on the downlink measurement pilot ports according to the received signals;

calculating a receiving weight vector of each downlink measurement pilot port, and using an uplink precoding weight vector, calculated and obtained by combining the receiving weight vector with uplink and downlink operating frequencies, for data precoding;

or, using N uplink precoding weight vectors, calculated and obtained by combining the receiving weight vector with uplink and downlink operating frequencies, for uplink pilot precoding, where N is the number of uplink precoding pilots transmitted, and N is an integer which is greater than or equal to 1.

14. The non-transitory computer-readable storage medium of claim 13, further comprising instructions that, when executed, cause the processing system to perform the steps of:

obtaining an uplink transmitting weight vector of each downlink measurement pilot port according to the uplink and downlink frequencies and the receiving weight vector of the corresponding downlink measurement pilot port;

using the one uplink precoding weight vector, obtained by weighting and combining uplink transmitting weight vectors of various downlink measurement pilot ports, for data precoding or uplink pilot precoding.

15. The non-transitory computer-readable storage medium of claim 13, wherein each downlink measurement pilot port is formed by the same set of antennas of a transmitting end using different precoding weights for transmission.

16. The non-transitory computer-readable storage medium of claim 13, further comprising instructions that, when executed, cause the processing system to perform the steps of:

performing screening on the downlink measurement pilot ports according to the magnitude of power or signal-to-noise ratios of the received signals.

17. The non-transitory computer-readable storage medium of claim 13, further comprising instructions that, when executed, cause the processing system to perform the steps of:

obtaining an uplink transmitting weight vector of the downlink measurement pilot port according to the receiving weight vector of the corresponding downlink measurement pilot port, and multiplying a ratio of an uplink operating frequency to a downlink operating frequency with a phase of the uplink transmitting weight vector.

18. The non-transitory computer-readable storage medium of claim 13, further comprising instructions that, when executed, cause the processing system to perform the steps of:

after calculating and obtaining the uplink precoding weight vector by combining the receiving weight vector with the uplink and downlink operating frequencies, further determining the number of uplink measurement pilots and/or an uplink measurement pilot precoding weight according to the uplink precoding weight vector and the number of the downlink measurement pilot ports;

or,

after calculating and obtaining the uplink precoding weight vector by combining the receiving weight vector with the uplink and downlink operating frequencies, further determining the number of uplink measurement pilots and/or an uplink measurement pilot precoding weight according to the uplink precoding weight vector and at least one of the following factors;

wherein the factors comprise;

(a) a precoding weight or a beam width of a downlink beam pilot;

(b) the number of downlink transmitting antennas;

(c) the number of uplink transmitting antennas; and

(d) signal-to-noise ratios of the received signals.