Signaling methods for frequency offset estimation using reference signals

Patent metadata

Field	Value
Publication number	US-10637709-B2
Application number	US-201715706183-A
Country	US
Kind code	B2
Filing date	Sep 15, 2017
Priority date	Jan 16, 2017
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

Methods, systems, and devices for wireless communication are described. Reference signals may be used for estimating frequency offset at a wireless device. For example, a first wireless device may identify a frequency offset estimation request for a second wireless device. The first wireless device may in turn transmit an initialization signal to the second wireless device to estimate the frequency offset, where the initialization signal may identify parameters for the transmission of a reference signal. The reference signal may then be transmitted to the second wireless device, and the second wireless device may estimate the frequency offset. In some examples, the second wireless device may send a request for the reference signal, where the request may include proposed parameters for the transmission of the reference signal. The first wireless device may accept the proposed parameters, or provide different parameters, and transmit the reference signal.

First claim

What is claimed is:

1. A method for wireless communication, comprising:
identifying a frequency offset estimation request for a wireless device in a system that supports millimeter wave (mmW) communications, the frequency offset estimation request comprising a request that a reference signal be communicated in a subsequent transmission for a frequency offset estimation;
identifying parameters for the reference signal to be communicated between a base station in the system and the wireless device for the frequency offset estimation, wherein the parameters indicate two or more port numbers corresponding to two or more ports for transmitting the reference signal, the two or more ports selected from a group of ports based at least in part on a carrier frequency offset or a Doppler shift associated with the selected two or more ports;
transmitting the reference signal based at least in part on the identified parameters using the two or more ports corresponding to the indicated two or more port numbers; and
receiving, at the base station from the wireless device, a second signal comprising a frequency offset estimate sent in response to the transmitted reference signal.

2. The method of claim 1 , further comprising transmitting an initialization signal including the frequency offset estimation request.

3. The method of claim 1 , wherein the identified parameters comprise a frequency domain pattern, a time domain pattern, a transmission time, a feedback scheme for the frequency offset estimate, or a combination thereof.

4. The method of claim 1 , wherein identifying the frequency offset estimation request comprises receiving a request from the wireless device.

5. The method of claim 4 , wherein the request from the wireless device comprises an indication of at least one proposed parameter, the at least one proposed parameter comprising a proposed frequency domain pattern, a proposed time domain pattern, one or more proposed port numbers, a proposed transmission time, a proposed feedback scheme for the frequency offset estimate, or a combination thereof.

6. The method of claim 5 , further comprising transmitting an indication of approval of the at least one proposed parameter.

7. The method of claim 4 , further comprising transmitting a first signal, the first signal identifying the parameters for the reference signal, wherein the first signal comprises an indication of an alternative reference signal parameter including an alternative frequency domain pattern, an alternative time domain pattern, one or more alternative port numbers, an alternative transmission time, an alternative feedback scheme for the frequency offset estimate, or a combination thereof.

8. The method of claim 1 , wherein the transmitting the reference signal comprises transmitting the reference signal at a predefined time or during a predefined transmission time interval (TTI).

9. The method of claim 1 , further comprising identifying the Doppler shift or the carrier frequency offset, the Doppler shift being associated with the wireless device, and the carrier frequency offset being between a transmitted signal and a received signal, or both, wherein the frequency offset estimate is based at least in part on the identified Doppler shift, or the identified carrier frequency offset between the transmitted signal and the received signal, or both.

10. The method of claim 1 , further comprising transmitting a signal using an adjusted frequency based at least in part on the frequency offset estimate.

11. The method of claim 1 , further comprising transmitting a signal using an adjusted frequency based at least in part on a recommended frequency adjustment.

12. The method of claim 1 , further comprising transmitting a first signal, the first signal identifying the parameters for the reference signal, wherein the first signal is transmitted using downlink control information (DCI) or using radio resource control (RRC) signaling.

13. The method of claim 1 , further comprising transmitting a first signal, the first signal identifying the parameters for the reference signal, wherein the first signal is transmitted using a channel state information reference signal (CSI-RS) report, a control channel, a data channel, a sounding reference signal (SRS), or a combination thereof.

14. The method of claim 1 , wherein the reference signal comprises a phase tracking reference signal (PT-RS), a mobility reference signal (MRS), a sounding reference signal (SRS), or a combination thereof.

15. The method of claim 1 , wherein the frequency offset estimation request is identified based at least in part on higher layer signaling.

16. The method of claim 1 , wherein the wireless device comprises a user equipment (UE).

17. The method of claim 1 , further comprising identifying the Doppler shift, the Doppler shift being associated with the wireless device, wherein identifying the parameters that indicate two or more port numbers corresponding to two or more ports for transmitting the reference signal is based at least in part on the Doppler shift associated with the wireless device.

18. A method for wireless communication, comprising:
identifying a frequency offset estimation request in a system that supports millimeter wave (mmW) communications, the frequency offset estimation request comprising a request that a reference signal be communicated in a subsequent transmission for a frequency offset estimation;
identifying parameters for the reference signal to be communicated between a base station in the system and the wireless device in the system for the frequency offset estimation, wherein the parameters indicate two or more port numbers corresponding to two or more ports for receiving the reference signal, the two or more ports selected from a group of ports based at least in part on a carrier frequency offset or a Doppler shift associated with the selected two or more ports;
receiving the reference signal based at least in part on the identified parameters using the two or more ports corresponding to the indicated two or more port numbers; and
transmitting, from the base station to the wireless device, a second signal comprising a frequency offset estimate sent in response to the transmitted reference signal.

19. The method of claim 18 , further comprising:
transmitting, to the wireless device, the frequency offset estimation request comprising the request that the reference signal be communicated; and
receiving a first signal based at least in part on the request that the reference signal be communicated, wherein identifying the parameters for the reference signal is based at least in part on the first signal.

20. The method of claim 19 , wherein the request that the reference signal be communicated comprises an indication of at least one proposed parameter, the at least one proposed parameter comprising a proposed frequency domain pattern, a proposed time domain pattern, one or more proposed port numbers, a proposed transmission time, a proposed feedback scheme for the frequency offset estimate, or a combination thereof.

21. The method of claim 18 , further comprising identifying the Doppler shift or the carrier frequency offset, the Doppler shift being associated with the wireless device, and the carrier frequency offset being between a transmitted signal and a received signal, or both, wherein the frequency offset estimate is based at least in part on the identified Doppler shift, or the identified carrier frequency offset between the transmitted signal and th

Assignees

• Qualcomm Inc

Inventors

• Bai Tianyang
• Cezanne Juergen
• Subramanian Sundar
• Li Junyi

Classifications

• H04L27/2657

  Carrier synchronisation · CPC title

• H04W56/0035

  detecting errors in frequency or phase · CPC title

• H04L5/005

  of common pilots, i.e. pilots destined for multiple users or terminals · CPC title

• H04L5/0035

  Resource allocation in a cooperative multipoint environment · CPC title

• H04L27/2646

  using feedback from receiver for adjusting OFDM transmission parameters, e.g. transmission timing or guard interval length · CPC title