BEAM REFINEMENT FOR MILLIMETER WAVE (MMW) SYSTEM

• US 20180279134A1
• Filed: 03/01/2018
• Published: 09/27/2018
• Est. Priority Date: 03/24/2017
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Malik, Rahul, Kadous, Tamer
• Granted Patent: US 10,716,013 B2
• Time in Patent Office: Days
• 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
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 72/046 the resource being in the space domain, e.g. beams

Abstract

Methods, systems, and devices for wireless communication are described for transmitting a first signal corresponding to a symbol so as to cover a geographic sector with via analog beamforming, transmitting, using analog beamforming and a second port, a second signal corresponding to the symbol, wherein aspects of the symbol are phase modulated with respect to the first signal such that corresponding aspects of a combined signal are beam-formed in one or more directions that at least partially overlap the geographic sector, a receiver receives the combined signal and from it determines a preferred refined beam for subsequent transmissions and transmits an indicator that includes the preferred refined beam, and the transmitter receives an indication from a receiver identifying one or more aspects of the combined signal, and determining a refined beam for subsequent transmissions based at least in part on the indication.

Claims

1. A method for wireless communication, comprising:

transmitting, using beamforming and a first port, a first signal corresponding to a symbol so as to cover a geographic sector;

transmitting, using beamforming and a second port, a second signal corresponding to the symbol, wherein aspects of the symbol are additionally modulated during the transmitting of the second signal with respect to the transmitting of the first signal such that corresponding aspects of a combined signal of the first signal and second signal are beam-formed in one or more directions that at least partially overlap the geographic sector;

receiving an indication from a receiver identifying one or more of the aspects of the combined signal, wherein the indication is based at least in part on measurements of the one or more of the aspects of the combined signal; and

determining a refined beam for subsequent transmissions based at least in part on the indication.

2. The method of claim 1, wherein the symbol is at least a portion of a reference symbol, at least a portion of a control symbol, or at least a portion of a data symbol.

3. The method of claim 1, further comprising:

transmitting a reference combined signal corresponding to a first time instance that includes a reference modulation applied to the second signal transmitted by the second port, with respect to the first signal transmitted by the first port; and

transmitting the combined signal corresponding to a second time instance, wherein aspects of the combined signal transmitted in the second time instance includes aspects that are beam-formed in one or more directions.

4. The method of claim 1, wherein the indication is further based on measurements of the one or more of the aspects of the combined signal in reference to corresponding aspects of the reference combined signal.

5. The method of claim 4, wherein the aspects of the combined signal comprise the relative amplitude or relative phase of a subset of tones of the combined signal.

6. The method of claim 1, further comprising:

phase-modulating or amplitude modulating different tones of the second signal such that the combined signal includes a plurality of tone beams each corresponding to one of the one or more directions.

7. The method of claim 6, further comprising:

grouping the tone beams into one of a frequency interleave or a block interleave so that more than one tone beam corresponds to one of the one or more directions.

8. The method of claim 6, further comprising:

repeating transmission of the first and second signals resulting in a second combined signal, wherein aspects of the second combined signal are beam-formed in one or more directions that at least partially overlap with a second geographic sector;

receiving a second indication from the receiver identifying one or more aspects of the second combined signal, wherein the second indication is based at least in part on measurements of the one or more of the aspects of the second combined signal; and

determining a refined beam for subsequent transmissions based at least in part on the first indication and the second indication.

9. The method of claim 1, further comprising:

transmitting, in additional signals, the symbol via additional ports, the additional signals being modulated with respect to the first signal such that the additional signals are digitally beam-formed in additional directions that at least partially overlap the geographic sector.

10. The method of claim 1, further comprising:

beam-forming the refined beam by rotating an analog-formed beam based at least in part on the indication, or by using digital or analog beam-forming, or a combination thereof, to increase a transmitted gain in a direction of the receiver.

11. The method of claim 1, wherein the indication comprises a direction to be used by the refined beam or a beam index corresponding to the direction to be used by the refined beam, or comprises the measurements of the gain of the combined signal.

12. The method of claim 1, further comprising:

including a sector identification, a network identification, a panel identification, or combinations thereof, in one or both of the first signal and the second signal.

13. The method of claim 1, further comprising:

transmitting the combined signal during a sector sweep phase; and

receiving the indication as part of feedback received from the receiver.

14. The method of claim 1, further comprising:

transmitting the combined signal in response to a request from the receiver for beam refinement.

15. The method of claim 1, wherein the combined signal is retransmitted at different times such that each transmission of the combined signal at different times corresponds to the one of the one or more directions.

16. A method for wireless communication, comprising:

receiving a first signal from a transmitter, the first signal corresponding to a symbol and transmitted so as to cover a geographic sector;

receiving a second signal from the transmitter, the second signal corresponding to the symbol, wherein aspects of the symbol are additionally modulated during transmission of the second signal with respect to a transmission of the first signal such that corresponding aspects of a combined signal of the first signal and the second signal are beam-formed in one or more directions that at least partially overlap the geographic sector;

measuring one or more of the aspects of the combined signal; and

determining a refined beam for subsequent transmissions based at least in part on the measuring.

17. The method of claim 16, wherein the symbol is a beam refinement symbol, at least a portion of a control symbol, or at least a portion of a data symbol.

18. The method of claim 16, further comprising:

receiving a reference combined signal corresponding to a first time instance that includes a reference modulation applied to the second signal transmitted by the second port, with respect to the first signal transmitted by the first port; and

receiving the combined signal corresponding to a second time instance, wherein aspects of the combined signal transmitted in the second time instance includes aspects that are beam-formed in one or more directions.

19. The method of claim 16, further comprising:

transmitting an indication of the refined beam to the transmitter.

20. The method of claim 19, wherein the indication is further based on measurements of the one or more of the aspects of the combined signal in reference to corresponding aspects of the reference signal.

21. The method of claim 16, wherein the first signal is in a first orthogonal frequency-division multiplexing (OFDM) symbol, and the second signal is in a second OFDM symbol, wherein the combined signal includes a plurality of tone beams each corresponding to one of the one or more directions.

22. The method of claim 16, further comprising:

measuring an aspect of the combined signal with reference to the reference combined signal comprises measuring a gain or a phase of the combined signal normalized by the gain of the reference combined signal.

23. The method of claim 16, further comprising:

receiving, from the transmitter, a repeated transmission of the first and second signals resulting in a second combined signal wherein aspects of the second combined signal are beam-formed in one or more directions that at least partially overlap with a second geographic sector;

measuring one or more of the aspects of the second combined signal with respect to a reference combined signal;

determining a different refined beam for subsequent transmissions based at least in part on the measuring; and

transmitting an indication identifying the different refined beam for subsequent transmissions.

24. The method of claim 16, further comprising:

transmitting an indication of the refined beam to the transmitter, wherein the indication comprises either a direction to be used by the refined beam or a beam index corresponding to the direction to be used by the refined beam.

25. The method of claim 16, further comprising:

identifying a sector identification, a network identification, a panel identification, or combinations thereof, in one or both of the first signal and the second signal.

26. The method of claim 16, further comprising:

receiving the combined signal during a sector sweep phase; and

transmitting an indication of the refined beam to the transmitter as part of a feedback message.

27. The method of claim 16, further comprising:

transmitting a request for beam refinement; and

receiving the first signal and the second signal in response to the request.

28. The method of claim 16, wherein the combined signal is received at different times such that each transmission of the combined signal at different times corresponds to one of the one or more directions.

29. An apparatus for wireless communication, comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to;

transmit, using beamforming and a first port, a first signal corresponding to a symbol so as to cover a geographic sector;

transmit, using beamforming and a second port, a second signal corresponding to the symbol, wherein aspects of the symbol are additionally modulated during the transmitting of the second signal with respect to the transmitting of the first signal such that corresponding aspects of a combined signal of the first signal and second signal are beam-formed in one or more directions that at least partially overlap the geographic sector;

receive an indication from a receiver identifying one or more of the aspects of the combined signal, wherein the indication is based at least in part on measurements of the one or more of the aspects of the second signal; and

determine a refined beam for subsequent transmissions based at least in part on the indication.

30. An apparatus for wireless communication, comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to;

receive a first signal from a transmitter, the first signal corresponding to a symbol and transmitted so as to cover a geographic sector;

receive a second signal from the transmitter, the second signal corresponding to the symbol, wherein aspects of the symbol are additionally modulated during transmission of the second signal with respect to a transmission of the first signal such that corresponding aspects of a combined signal of the first signal and the second signal are beam-formed in one or more directions that at least partially overlap the geographic sector;

measure one or more of the aspects of the combined signal; and

determine a refined beam for subsequent transmissions based at least in part on the measuring.