Techniques for beam shaping at a millimeter wave base station and a wireless device and fast antenna subarray selection at a wireless device

Patent metadata

Field	Value
Publication number	US-2016198474-A1
Application number	US-201514822681-A
Country	US
Kind code	A1
Filing date	Aug 10, 2015
Priority date	Jan 6, 2015
Publication date	Jul 7, 2016
Grant date	—

Abstract

Methods, systems, and devices are described for wireless communication at a user equipment (UE). A wireless communications system may improve UE discovery latency by dynamically selecting and switching beam forming codebooks at the millimeter wave base station and the wireless device. Selecting an optimal beam forming codebook may allow the wireless communication system to improve link margins between the base station without compromising resources. In some examples, a wireless device may determine whether the received signals from the millimeter wave base station satisfy established signal to noise (SNR) thresholds, and select an optimal beam codebook to establish communication. Additionally or alternately, the wireless device may further signal the selected beam codebook to the millimeter wave base station and direct the millimeter wave base station to adjust its codebook based on the selection.

First claim

What is claimed is:

1 . A method of wireless communications, comprising:
receiving, at a wireless device, a first signal from a millimeter wave base station using a first beam codebook; dynamically determining that a second beam codebook, different from the first beam codebook, is to be used on the first signal; and transmitting a second signal to the millimeter wave base station requesting the millimeter wave base station to use the second beam codebook.

2 . The method of claim 1 , further comprising:
determining whether a quality of the first signal is above or below a first threshold; wherein the dynamically determining that the second beam codebook is to be used is based at least in part on the determining whether the quality of the first signal is above or below the first threshold.

3 . The method of claim 2 , wherein the second signal comprises a signal energy estimate, a beamforming vector index, information for beamforming, or a combination thereof.

4 . The method of claim 1 , further comprising:
determining whether a quality of the first signal is above or below a second threshold; and dynamically selecting the second beam codebook based at least in part on the determining whether the quality of the first signal is above or below the second threshold.

5 . The method of claim 1 , further comprising:
identifying a first receiver beam codebook used at the wireless device as being associated with the first beam codebook used by the millimeter wave base station; and switching from the first receiver beam codebook to a second receiver beam codebook associated with the second beam codebook used by the millimeter wave base station.

6 . The method of claim 2 , further comprising:
adapting the first threshold based at least in part on a selection of the second beam codebook.

7 . The method of claim 2 , wherein the second beam codebook is selected in response to determining that the quality of signal falls below the first threshold.

8 . The method of claim 1 , wherein the second beam codebook is selected from a group comprising at least one of:
a coarse codebook; an intermediate codebook; a fine codebook; a wireless-device specific codebook; a beam negation codebook; a codebook of beams trading off signal quality to a specific wireless device; or a combination of beamforming vectors from different codebooks.

9 . The method of claim 1 , wherein the second signal comprises a request for the millimeter wave base station to switch to the second beam codebook.

10 . The method of claim 9 , wherein the request for the millimeter wave base station to switch to the second beam codebook is based at least in part on at least one of: hardware or software complexity issues for radio frequency chains, maintenance of link issues, or performance improvement with metrics such as rate, reliability, or a combination thereof.

11 . The method of claim 9 , further comprising:
transmitting the second signal via a random access channel (RACH) using a coarse codebook.

12 . The method of claim 9 , further comprising:
transmitting the second signal over a low-frequency carrier network coexisting with a millimeter wave carrier network.

13 . The method of claim 9 , wherein the second signal comprises a distress signal transmitted with a unique identification at a high code rate.

14 . The method of claim 1 , wherein the first signal is a directional primary synchronization signal (DPSS).

15 . The method of claim 1 , further comprising:
calculating a signal-to-noise ratio (SNR) of the first signal to determine a quality of the first signal.

16 . An apparatus for wireless communications, comprising:
a processor; memory in electronic communication with the processor; and instructions stored in the memory; wherein the instructions are executable by the processor to: receive, at a wireless device, a first signal from a millimeter wave base station using a first beam codebook; dynamically determine that a second beam codebook, different from the first beam codebook, is to be used on the first signal; and transmit a second signal to the millimeter wave base station requesting the millimeter wave base station to use the second beam codebook.

17 . The apparatus of claim 16 , wherein the instructions are executable by the processor to:
determine whether a quality of the first signal is above or below a first threshold; wherein the dynamically determining that the second beam codebook is to be used is based at least in part on the determining whether the quality of the first signal is above or below the first threshold.

18 . The apparatus of claim 17 , wherein the second signal comprises a signal energy estimate, a beamforming vector index, information for beamforming, or a combination thereof.

19 . The apparatus of claim 16 , wherein the instructions are executable by the processor to:
determine whether a quality of the first signal is above or below a second threshold; and dynamically select the second beam codebook based at least in part on the determining.

20 . The apparatus of claim 16 , wherein the instructions are executable by the processor to:
identify a first receiver beam codebook used at the wireless device as being associated with the first beam codebook used by the millimeter wave base station; and switch from the first receiver beam codebook to a second receiver beam codebook associated with the second beam codebook used by the millimeter wave base station.

21 . The apparatus of claim 17 , wherein the instructions are executable by the processor to:
adapt the first threshold based at least in part on a selection of the second beam codebook.

22 . The apparatus of claim 17 , wherein the second beam codebook is selected in response to determining that the quality of signal falls below the first threshold.

23 . The apparatus of claim 16 , wherein the second beam codebook is selected from a group comprising at least one of:
a coarse codebook; an intermediate codebook; a fine codebook; a wireless-device specific codebook; a beam negation codebook; a codebook of beams trading off signal quality to a specific wireless device; or a combination of beamforming vectors from different codebooks.

24 . The apparatus of claim 16 , wherein the second signal comprises a request for the millimeter wave base station to switch to the second beam codebook.

25 . An apparatus for wireless communications, comprising:
means for receiving, at a wireless device, a first signal from a millimeter wave base station using a first beam codebook; means for dynamically determining that a second beam codebook, different from the first beam codebook, is to be used on the first signal; and means for transmitting a second signal to the millimeter wave base station requesting the millimeter wave base station to use the second beam codebook.

26 . The apparatus of claim 25 , further comprising:
means for determining whether a quality of the first signal is above or below a first threshold; wherein the dynamically determining that the second beam codebook is to be used is based at least in part on the determining whether the quality of the first signal is above or below the first threshold.

27 . The apparatus of claim 26 wherein the second signal comprises a signal energy estimate, a beamforming vector index, in

Assignees

• Qualcomm Inc

Inventors

• Raghavan Vasanthan
• Cezanne Juergen
• Subramanian Sundar
• Sampath Ashwin
• Li Junyi

Classifications

• H04W72/542

  using measured or perceived quality · CPC title

• H04B7/0456 Primary

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

• H04B7/0874

  using subgroups of receive antennas · CPC title

• H04W72/0466 Primary

  the resource being a scrambling code · CPC title

• H04B7/0639 Primary

  Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection · CPC title