Systems and methods for beamforming and rate control in a multi-input multi-output communication systems

• US 20060203891A1
• Filed: 07/20/2005
• Published: 09/14/2006
• Est. Priority Date: 03/10/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gore, Dhananjay Ashok, Gorokhov, Alexei, Sampath, Hemanth, Kadous, Tamer
• Granted Patent: US 9,246,560 B2
• Time in Patent Office: Days
• US Class Current: 375/132
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0617 for beam forming
• 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 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems

Abstract

Methods and apparatuses are disclosed that determine a type of channel information based upon whether a wireless device is scheduled to receive symbols. In addition, a determination may be as to a number of hop periods to determine the type of channel information. Further, a distance between hop regions may be utilized to determine a type of channel information.

Claims

1. An apparatus comprising:

a memory; and

a processor coupled with the memory, the processor operable to generate one of a hybrid channel information with optimal rank, a broadband channel information with optimal rank, or a beamformed channel information with optimal rank based upon whether the apparatus is scheduled.

2. The apparatus of claim 1, wherein the processor is further operable to determine whether the apparatus is scheduled if the apparatus has received an instruction that it will receive symbols in a next hop period.

3. The apparatus of claim 1, wherein the processor is further operable to determine whether the apparatus is scheduled if the apparatus has received an instruction that it will receive symbols in at least one of N next hop periods.

4. The apparatus of claim 1, wherein the processor is further operable to generate one of the hybrid channel information with optimal rank, broadband channel information with optimal rank, or beamformed channel information with optimal rank based upon whether the apparatus is scheduled and a number of hop periods.

5. The apparatus of claim 1, wherein the processor is further operable to generate one of the hybrid channel information with optimal rank, a broadband channel information with optimal rank, or beamformed channel information with optimal rank based upon whether the apparatus is scheduled and a distance between a prior hop region and a current hop region.

6. The apparatus of claim 1, wherein the prior hop region is the immediately prior hop region.

7. The apparatus of claim 1, wherein the processor is further operable to cause transmission of the signal utilizing an orthogonal frequency division multiplexing (OFDM) scheme.

8. The apparatus of claim 1, wherein the processor is further operable to generate the hybrid channel information by modifying the broadband channel information based upon a difference between the broadband channel information and the beamformed channel information.

9. The apparatus of claim 1, wherein each of the hybrid channel information with optimal rank, broadband channel information with optimal rank, and beamformed channel information with optimal rank consists of 7 bits.

10. The apparatus of claim 1, wherein the optimal rank consists of 2 bits.

11. The apparatus of claim 1, wherein the processor is further operable to quantize hybrid channel information with optimal rank, broadband channel information with optimal rank, and beamformed channel information with optimal rank.

12. The apparatus of claim 1, wherein the processor is further operable to generate the hybrid channel information and beamformed channel information based upon only dominant eigenbeams.

13. The apparatus of claim 1, wherein the channel information comprises CQI. The CQI constitutes a signal to noise ratio estimation for the received symbols.

14. The apparatus of claim 13, wherein the CQI incorporates thermal noise, interference covariance matrix or the interference variance per receive antenna.

15. The apparatus of claim 14, wherein the processor is further configured to estimate the interference covariance matrix or interference variance per receive antenna from broadband pilots, or dedicated pilots or a hybrid scheme which can include interference estimated from broadband and dedicated pilots.

17. The method of claim 14, wherein determining whether the wireless communication device is scheduled comprises determining if the wireless communication device has received an instruction that it will receive symbols in a next hop period.

18. The method of claim 14, wherein determining whether the wireless communication device is scheduled comprises determining if the wireless communication device has received an instruction that it will receive symbols in at least one of N next hop periods.

19. The method of claim 14, further comprising

determining a number of hop periods;

if the number of hop periods is greater than a predetermined number, generating one of the hybrid channel information or beamformed channel information; and

if the number of hop periods is less than the predetermined number, generating the broadband channel information or hybrid channel information.

20. The method of claim 14, further comprising

determining whether a distance between a prior hop region and a current hop region exceeds a threshold;

if the distance is greater than the threshold, generating one of the hybrid channel information or beamformed channel information; and

if the distance is less than the threshold, generating the broadband channel information or hybrid channel information.

21. The method of claim 18, wherein the prior hop region is the immediately prior hop region.

22. The method of claim 14, wherein each of the broadband channel and beamformed channel information consists of 5 bits.

23. The method of claim 14, further comprising quantizing the generated broadband channel information or beamformed channel information.

24. The method of claim 14, wherein the beamformed channel information is generated based upon only dominant eigenbeams.

25. The method of claim 14, wherein the channel information comprises CQI.

27. The apparatus of claim 14, wherein the means for determining whether the wireless communication device is scheduled comprises means for determining if the wireless communication device has received an instruction that it will receive symbols in a next hop period.

28. The apparatus of claim 24, wherein the means for determining whether the wireless communication device is scheduled comprises means for determining if the wireless communication device has received an instruction that it will receive symbols in at least one of N next hop periods.

29. The apparatus of claim 24, further comprising means for determining a number of hop periods and wherein the means for generating comprises means for generating one of the hybrid channel information with optimal rank, the broadband channel information with optimal rank, or the beamformed channel information with optimal rank based upon whether the apparatus is scheduled and the number of hop periods.

30. The apparatus of claim 24, further comprising whether a distance between a prior hop region and a current hop region exceeds a threshold and wherein the means for generating comprises means for generating one of the hybrid channel information with optimal rank, the broadband channel information with optimal rank, or the beamformed channel information with optimal rank based upon whether the apparatus is scheduled and whether the distance between the prior hop region the current hop region exceeds the threshold.

31. The apparatus of claim 28, wherein the prior hop region is the immediately prior hop region.

32. The apparatus of claim 24, wherein the channel information comprises CQI.

16. A method comprising:

determining whether a wireless communication device is scheduled to receive symbols;

if the wireless communication device is scheduled to receive symbols, then generating beamformed channel information; and

if the wireless communication device is not scheduled to receive symbols, then generating broadband channel information.

26. An apparatus comprising:

means for determining whether a wireless communication device is scheduled to receive symbols; and

means for generating one of a hybrid channel information with optimal rank, a broadband channel information with optimal rank, or a beamformed channel information with optimal rank based upon whether the apparatus is scheduled.