METHOD FOR TRANSMITTING A REFERENCE SIGNAL, METHOD FOR DETERMINING PHASE NOISE AND RELATED APPARATUSES

• US 20190326964A1
• Filed: 08/25/2017
• Published: 10/24/2019
• Est. Priority Date: 12/28/2016
• Status: Active Grant

• Current Assignee: Datang Mobile Communications Equipment Company Limited (China Information Communication Technology Group Co. Ltd.)
• Original Assignee: China Academy of Telecom Technology (China Information Communication Technology Group Co. Ltd.)
• Inventors: LI, Hui, GAO, Qiubin, SU, Xin, PAKESH, Tamrakar, CHEN, Runhua, HUANG, Qiuping, LI, Chuanjun, WANG, Mengjun
• Granted Patent: US 10,659,119 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0473 taking constraints in layer or codeword to antenna mapping into account
• CPC Class Codes: H04B 7/0478 Special codebook structures directed to feedback optimisation
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas
• CPC Class Codes: H04L 25/02 Details ; arrangements for supplying electrical power along data transmission lines systems for transmitting signals via power distribution lines H04B3/54
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 27/26 Systems using multi-frequency codes H04L27/32 takes precedence
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/2611 Distribution thereof
• CPC Class Codes: H04L 27/266 Fine or fractional frequency offset determination and synchronisation
• CPC Class Codes: H04L 27/2675 Pilot or known symbols
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal

Abstract

The present invention relates to the field of wireless communications, and in particular, to a method for transmitting a reference signal, a method for determining a phase noise, and related apparatuses, to resolve the problem in the prior art that different phase noises of different antenna units or antenna ports of a transmitter cannot be accurately estimated and compensated for. The method comprises: the transmitter respectively transmitting each precoded DMRS and PTRS to a receiver via respective corresponding antenna groups having a same phase noise, and when the receiver receives the PTRS, performing channel estimation based on each received PTRS, to determine phase changes caused by phase noises corresponding to different antenna groups. In this way, even if different antennas of a transmitter have different phase noises, phase changes caused by the different phase noises can still be accurately determined, so that all data transmitted by the different antenna groups can be accurately demodulated according to different phase changes.

Claims

1. A method for transmitting a reference signal, comprising:

pre-coding, by a transmitter, each data stream, and transmitting each data stream over its corresponding one or more antenna groups, wherein antenna elements or antenna ports in a same antenna group have a same phase noise, and all antenna groups corresponding to one data stream have a same phase noise;

pre-coding, by the transmitter, a Demodulation Reference Signal (DMRS) of each DMRS port, and transmitting each DMRS over its corresponding one or more antenna groups, wherein all antenna groups corresponding to one DMRS port have a same phase noise, and one data stream corresponds to one DMRS port; and

pre-coding, by the transmitter, a Phase-Tracking Reference Signal (PTRS) of each PTRS port, and transmitting the PTRS over its corresponding one or more antenna groups, wherein all antenna groups corresponding to one PTRS port have a same phase noise, and one PTRS port corresponds to at least one DMRS port.

2. The method according to claim 1, wherein the transmitter pre-codes a data stream in such a way that weights for antenna elements or antenna ports in the other antenna groups than an antenna group corresponding to the data stream are zero;

the transmitter pre-codes a DMRS in such a way that weights for antenna elements or antenna ports in the other antenna groups than an antenna group corresponding to the DMRS are zero; and

the transmitter pre-codes a PTRS in such a way that weights for antenna elements or antenna ports in the other antenna groups than an antenna group corresponding to the PTRS are zero.

3. The method according to claim 1, further comprising:

determining, by the transmitter, a first mapping relationship between the respective PTRS ports and the respective DMRS ports, wherein in the first mapping relationship, one PTRS port is mapped to at least one DMRS port, and the PTRS port and its mapped DMRS port use a same antenna group for transmission.

4. The method according to claim 3, further comprising:

transmitting, by the transmitter, the first mapping relationship to a receiver after determining the first mapping relationship;

or

pre-agreeing, by the transmitter, with a receiver on the first mapping relationship;

wherein transmitting, by the transmitter, the first mapping relationship to the receiver comprises;

transmitting, by the transmitter, the first mapping relationship to the receiver via higher-layer signaling;

or

transmitting, by the transmitter, the first mapping relationship to the receiver via dynamic control signaling.

6. The method according to claim 1, further comprising:

determining, by the transmitter, a second mapping relationship between the respective data streams to be transmitted and the respective DMRS ports, wherein in the second mapping relationship, one data stream is mapped to one DMRS port, and the data stream and its mapped DMRS port correspond to a same antenna group for transmission.

7. The method according to claim 6, further comprising:

transmitting, by the transmitter, the second mapping relationship to a receiver after determining the second mapping relationship;

or

pre-agreeing, by the transmitter, with a receiver on the second mapping relationship;

wherein transmitting, by the transmitter, the second mapping relationship to the receiver comprises;

transmitting, by the transmitter, the second mapping relationship to the receiver via higher-layer signaling;

or

transmitting, by the transmitter, the second mapping relationship to the receiver via dynamic control signaling.

9. The method according to claim 1, wherein precoder used by the transmitter for a PTRS is the same as precoder used by a data stream over a sub-carrier occupied by the PTRS, said data stream corresponds to a DMRS port corresponding to the PTRS.

5. (canceled)

8. (canceled)

10. (canceled)

11. A method for determining phase noise, comprising:

receiving, by a receiver, a Demodulation Reference Signals (DMRS) transmitted by a transmitter over one or more antenna groups corresponding to each DMRS port, performing first channel estimation respectively based upon each received DMRS, and obtaining a first channel estimation result corresponding to each DMRS;

receiving, by the receiver, a Phase-Tracking Reference Signals (PTRS) transmitted by the transmitter respectively over one or more antenna groups corresponding to each PTRS port, performing second channel estimation respectively based upon each received PTRS, and obtaining a second channel estimation result corresponding to each PTRS;

determining, by the receiver, a first mapping relationship, wherein the first mapping relationship represents a correspondence relationship between the respective PTRS, ports and the respective DMRS ports, one PTRS port corresponds to at least one DMRS port, and the PTRS port and its corresponding DMRS port use a same antenna, group for transmission; and

calculating, by the receiver, a phase change, in a symbol comprising the PTRS, arising from a phase noise of the antenna groups corresponding to each PTRS port respectively using the second channel estimation result of each PTRS and the first channel estimation result of its corresponding DMRS based upon the first mapping relationship.

12. The method according to claim 11, wherein the first mapping relationship is obtained by the receiver as notified by the transmitter, or the first mapping relationship is pre-agreed between the receiver and the transmitter.

13. The method according to claim 11, further comprising:

receiving, by the receiver, respective data streams transmitted by the transmitter respectively on their corresponding antenna groups;

determining, by the receiver, a second mapping relationship, wherein the second mapping relationship represent a correspondence relationship between the respective data streams and the respective DMRS ports, one data stream corresponds to one DMRS port, and the data stream and its corresponding DMRS port correspond to a same antenna group for transmission; and

performing, by the receiver, following operations respectively on each data stream based upon the second mapping relationship;

determining a first channel estimation result estimated on a DMRS port corresponding to the data stream;

compensating for the first channel estimation result using a phase change arising from phase noise of one or more antenna groups corresponding to the DMRS port; and

demodulating the data stream using the compensated first channel estimation result.

14-21. -21. (canceled)

22. An apparatus for transmitting a reference signal, comprising:

a processor, a transceiver, and a memory, wherein;

the processor is configured to read and execute program in the memory;

to transmit data streams, Demodulation Reference Signals (DMRSs), and Phase-Tracking Reference Signals (PTRSs) through the transceiver;

to pre-code each data stream, and then transmit each data stream over its corresponding one or more antenna groups, wherein antenna elements or antenna ports in a same antenna group have a same phase noise, and all antenna groups corresponding to one data stream have a same phase noise;

to pre-code a DMRS of each DMRS port, and transmit each DMRS over its corresponding one or more antenna groups, wherein all antenna groups corresponding to one DMRS port have a same phase noise, and one data stream corresponds to one DMRS port; and

to pre-code a PTRS of each PTRS port, and transmit each PTRS over its corresponding one or more antenna groups, wherein all antenna groups corresponding to one PTRS port have a same phase noise, and one PTRS port corresponds to at least one PTRS port; and

the transceiver is configured to transmit and receive data under the control of the processor.

23. The apparatus according to claim 22, wherein the processor is configured:

to pre-code a data stream in such a way that weights for antenna elements or antenna ports in the other antenna groups than an antenna group corresponding to the data stream are zero;

to pre-code a DMRS in such a way that weights for antenna elements or antenna ports in the other antenna groups than an antenna group corresponding to the DMRS are zero; and

to pre-code a PTRS in such a way that weights for antenna elements or antenna ports in the other antenna groups than an antenna group corresponding to the PTRS are zero.

24. The apparatus according to claim 22, wherein the processor is configured:

to determine a first mapping relationship between the respective PTRS ports and the respective DMRS ports, wherein in the first mapping relationship, one PTRS port is mapped to at least one DMRS port, and the PTRS port and its mapped DMRS port use a same antenna group for transmission.

25. The apparatus according to claim 24, wherein the processor is configured:

to transmit the first mapping relationship to a receiver after determining the first mapping relationships;

or

to pre-agree with a receiver on the first mapping relationship;

wherein the processor configured to transmit the first mapping relationship to the receiver is configured;

to transmit the first mapping relationship to the receiver via higher-layer signaling;

or

to transmit the first mapping relationship to the receiver via dynamic control signaling.

27. The apparatus according to claim 22, wherein the processor is configured:

to determine a second mapping relationship between the respective data streams to be transmitted and the respective DMRS ports, wherein in the second mapping relationship, one data stream is mapped to one DMRS port, and the data stream and its mapped DMRS port correspond to a same antenna group for transmission.

28. The apparatus according to claim 27, wherein the processor is configured:

to transmit the second mapping relationship to a receiver after determining the second mapping relationship;

or

to pre-agree with a receiver on the second mapping relationship;

wherein the processor configured to transmit the second mapping relationship to the receiver;

to transmit the second mapping relationship to the receiver via higher-layer signaling;

or

to transmit the second mapping relationship to the receiver via dynamic control signaling.

30. The apparatus according to claim 22, wherein precoder used by the processor for a PTRS is the same as precoder used by a data stream over a sub-carrier occupied by the PTRS, said dada stream corresponds to a DMRS port corresponding to the PTRS.

26. (canceled)

29. (canceled)

31. (canceled)

32. An apparatus for determining phase noise, comprising:

a processor, a transceiver, a memory, and a user interface, wherein;

the processor is configured to read and execute program in the memory;

to receive data streams, Demodulation Reference Signals (DMRSs), and Phase-Tracking Reference Signals (PTRSs) through the transceiver;

to receive a DMRS transmitted by a transmitter over one or more antenna groups corresponding to each DMRS port, to perform first channel estimation respectively based upon each received DMRS, and to obtain a corresponding first channel estimation result corresponding to each DMRS;

to receive a PTRS transmitted by the transmitter respectively over one or more antenna groups corresponding to each PTRS port, to perform second channel estimation respectively based upon each received PTRS, and to obtain a corresponding second channel estimation result corresponding to each PTRS;

to determine a first mapping relationship, wherein the first mapping relationship represents a correspondence relationship between the respective PTRS ports and the respective DMRS ports, one PTRS port corresponds to at least one DMRS port, and the PTRS port and its corresponding DMRS port use a same antenna group for transmission; and

to calculate a phase change, in a symbol comprising the PTRS, arising from a phase noise of the antenna groups corresponding to each PTRS port respectively using the second channel estimation result of each PTRS and the first channel estimation result of its corresponding DMRS based upon the first mapping relationship; and

the transceiver is configured to transmit and receive data under the control of the processor.

33. The apparatus according to claim 32, wherein the first mapping relationship is obtained by the processor as notified by the transmitter, or the first mapping relationship is pre-agreed between the processor and the transmitter.

34. The apparatus according to claim 32, wherein the processor is configured:

to receive respective data streams transmitted by the transmitter respectively over their corresponding antenna groups;

to determine a second mapping relationship, wherein the second mapping relationship represents a correspondence relationship between the respective data streams and the respective DMRS ports, one data stream corresponds to one DMRS port, and the data stream and its corresponding DMRS port correspond to a same antenna group for transmission; and

to perform following operations respectively on each data stream based upon the second mapping relationship;

determining a first channel estimation result estimated on a DMRS port corresponding to the data stream;

compensating for the first channel estimation result using a phase change arising from phase noise of an antenna group corresponding to the DMRS port; and

demodulating the data stream using the compensated first channel estimation result.

35-37. -37. (canceled)