System and method for communications system training

Patent metadata

Field	Value
Publication number	US-10651900-B2
Application number	US-201815983692-A
Country	US
Kind code	B2
Filing date	May 18, 2018
Priority date	May 18, 2018
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

A method for operating a communication device includes receiving a first transmission including a first signal on one or more resources associated with signal reception, deriving a receive filter in accordance with the received first transmission, deriving a transmit filter in accordance with the receive filter, precoding a second signal with the transmit filter, thereby producing a second transmission, and transmitting the second transmission.

First claim

What is claimed is:

1. A computer implemented method for operating a communications device, the method comprising:
receiving, by the communications device from one or more access nodes, a first transmission including a first signal on one or more resources associated with signal reception;
deriving, by the communications device, a receive filter in accordance with the received first transmission;
deriving, by the communications device, a transmit filter in accordance with the receive filter;
precoding, by the communications device, a second signal with the transmit filter, thereby producing a second transmission; and
transmitting, by the communications device to the one or more access nodes, the second transmission on a plurality of second transmission ports, the second transmission having a same number of transmission ports as the first transmission and in a one-to-one mapping.

2. The method of claim 1 , wherein each first transmission port corresponds to a transmission layer, and a number of transmission layers of the first transmission corresponds to a first transmission rank.

3. The method of claim 2 , wherein the transmit filter is a weighted version of the receive filter weighted by weights associated with each of the transmission layers.

4. The method of claim 1 , wherein the resources associated with signal reception comprise at least one of non-zero-power (NZP) channel state information reference signal (CSI-RS) resources configured for channel and interference measurement, NZP CSI-RS resources configured for channel measurement, demodulation reference signal (DMRS) resources, or physical downlink shared channel (PDSCH) resources.

5. The method of claim 1 , wherein the communications device further receives interference on resources associated with interference transmission, and wherein deriving the receive filter further comprising deriving, by the communications device, the receive filter in accordance with the received first transmission and the received interference.

6. The method of claim 5 , wherein the resources associated with interference transmission comprise at least one of NZP CSI-RS resources configured for channel and interference measurement, NZP CSI-RS resources configured for channel measurement, NZP CSI-RS resources configured for interference measurement, zero-power (ZP) CSI-RS resources configured for interference measurement, CSI interference measurement resources, DMRS resources, or PDSCH resources.

7. The method of claim 5 , wherein the communications device derives the receive filter in accordance with the received first transmission and the received interference on resources associated with signal reception and interference transmission that are partially overlapped or completely overlapped.

8. The method of claim 5 , further comprising sending, by the communications device to the one or more access nodes, feedback information based on the received first transmission and the received interference.

9. The method of claim 1 , further comprising repeating, by the communications device, the receiving, the deriving the receive filter, the deriving the transmit filter, the precoding, and the transmitting until an end criterion is met.

10. The method of claim 9 , wherein the end criterion comprises at least one of a signal plus interference to noise ratio (SINR) meeting a threshold, or the communications device receiving an instruction to stop training.

11. The method of claim 1 , wherein the second transmission is one of a sounding reference signal (SRS) transmission or a DMRS transmission.

12. The method of claim 1 , wherein the transmit filter and the receive filter are equivalent.

13. The method of claim 12 , wherein the transmit filter and the receive filter are at least one of conjugate transposed versions of each other, conjugated versions of each other, scaled versions of each other, normalized versions of each other, or are identical to each other.

14. The method of claim 1 , wherein the receive filter is derived in accordance with a minimum mean square error (MMSE) combiner.

15. The method of claim 1 , further comprising sending, by the communications device to the one or more access nodes prior to receiving the first transmission, a precoded SRS or a non-precoded SRS.

16. The method of claim 15 , wherein the communications device transmits the SRS with the same filter used for a reception of a periodic CSI-RS or a semi-persistent CSI-RS, and for a reception of interference.

17. The method of claim 1 , wherein the first and second transmissions occur over one or more subbands, and wherein the receive filter and the transmit filter are separately derived for each subband.

18. The method of claim 1 , wherein the transmit filter comprises a multi-antenna precoder, and wherein the receive filter comprises a multi-antenna combiner.

19. A computer implemented method for operating an access node in a training mode, the method comprising:
precoding, by the access node, a first signal with a transmit filter, thereby producing a first transmission;
transmitting, by the access node to a communications device, the first transmission on a plurality of first transmission ports;
receiving, by the access node from the communications device, a second transmission including a second signal, the second signal being received on resources associated with signal reception, the second including a same number of transmission ports as the first transmission and in a one-to-one mapping;
deriving, by the access node, a receive filter in accordance with the received second transmission; and
deriving, by the access node, the transmit filter in accordance with the receive filter.

20. The method of claim 19 , further comprising repeating, by the access node, the precoding, the transmitting, the receiving, the deriving the receive filter, and the deriving the transmit filter until an end criterion is met.

21. The method of claim 20 , wherein the end criterion comprises a signal plus interference to noise ratio (SINR) meeting a threshold.

22. The method of claim 19 , further comprising receiving, by the access node from the communications device, feedback information, and wherein deriving the receive filter is in accordance with the feedback information.

23. The method of claim 19 , wherein the method further comprises:
reducing, by the access node, a first transmission rank when in response to a SINR of at least one transmission layer of the second transmission being below a threshold; and
signaling, by the access node to the communications device, the reduced first transmission rank.

24. The method of claim 19 , further comprising sending, by the access node to the communications device, an instruction to stop operating in the training mode.

25. The method of claim 19 , wherein deriving the receive filter comprises adjusting the receive filter to maximize a signal plus interference noise ratio (SINR) of a communications system including the communications device and the access node.

26. The method of claim 19 , further comprising receiving, by the access node from the communications device prior to precoding the first signal, a sounding reference signal (SRS) or a non-precoded SRS.

27. The method of claim 26 , wherein the transmit filter is selected in accordance with the SRS or the non-precoded SRS.

28. The method of claim 19 , further comprising

Assignees

• Futurewei Technologies Inc

Inventors

• Maamari Diana
• Liu Jialing
• Cheng Qian
• Xiao Weimin
• Zhou Hao
• Soong Anthony C K

Classifications

• H04B7/0417 Primary

  Feedback systems · CPC title

• H04L5/0055

  Physical resource allocation for ACK/NACK (for physical mapping arrangements in ARQ protocols H04L1/1861) · CPC title

• H04L5/0051

  of dedicated pilots, i.e. pilots destined for a single user or terminal · CPC title

• H04B7/0456 Primary

  Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting · CPC title

• H04B7/0626

  Channel coefficients, e.g. channel state information [CSI] · CPC title