Method and wireless systems using multiple antennas and adaptive control for maximizing a communication parameter

• US 6,351,499 B1
• Filed: 12/15/1999
• Issued: 02/26/2002
• Est. Priority Date: 12/15/1999
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Iospan Wireless, Inc. (Intel Corporation)
• Inventors: Tellado, Jose, Gesbert, David J., Paulraj, Arogyaswami J., Sebastian, Peroor K.
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): JIANG, LENNY R
• Application Number:
  US09/464,372
• Time in Patent Office: 804 Days
• Field of Search: 375/259, 375/260, 375/267, 375/285-295, 375/296, 375/299, 375/316, 375/340, 375/346, 375/347, 370/310, 370/329, 370/334, 370/332
• US Class Current: 375/267
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 3/2605 Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas space-time coding H04L1/0618
• CPC Class Codes: H04B 7/0673 using feedback from receiving side
• CPC Class Codes: H04B 7/0697 using spatial multiplexing
• CPC Class Codes: H04B 7/0857 using maximum ratio combining techniques, e.g. signal-to- interference ratio [SIR], received signal strenght indication [RSS]
• CPC Class Codes: H04B 7/0891 Space-time diversity rake receivers H04B1/7115; space-time decoding H04L1/0631
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/06 using space diversity
• CPC Class Codes: H04L 1/0606 Space-frequency coding
• CPC Class Codes: H04L 1/0618 Space-time coding

Abstract

A method of maximizing a communication parameter, such as data capacity, signal quality or throughput of a channel between a transmit unit with M transmit antennas and a receive unit with N receive antennas and a communication system such as a wireless network (including networks with multiple access techniques such as TDMA, FDMA, CDMA, OFDMA) employing the method. The data is first processed to produce parallel spatial-multiplexed streams SM_i, where i=1 . . . k, which are converted or mapped to transmit signals TS_p, where p=1 . . . M, assigned for transmission from the M transmit antennas. Corresponding receive signals RS_j, where j=1 . . . N, are received by the N receive antennas of the receiver and used to assess a quality parameter, such as a statistical signal parameter including SINR, SNR, power level, level crossing rate, level crossing duration of the signal of a predetermined threshold and reception threshold, or a parameter of the data, such as BER or packet error rate. The quality parameter is used to adaptively adjust k as well as other parameters such as coding and mapping to transmit antennas such that the communication parameter of the channel is maximized.

Claims

1. A method of maximizing a communication parameter of a channel between a transmit unit having a number M of transmit antennas and a receive unit having a number N of receive antennas, said method comprising the following steps:

a) processing said data to produce parallel spatial-multiplexed streams SM_i, where i=1 . . . k;

b) mapping said spatial-multiplexed streams SM_i to transmit signals TS_p, where p=1 . . . M, for transmission from said M transmit antennas to said receiver via said channel, wherein the mapping comprises processing each of said spatial-multiplexed streams SM_i by a coding unit to produce coded streams CS_h, where h=1 . . . k′

;

c) receiving receive signals RS_j, where j=1 . . . N by said N receive antennas;

d) assessing a quality parameter of said receive signals RS_j;

e) using said quality parameter to adjust k to maximize said communication parameter of said channel; and

f) using said quality parameter in said transmit unit to adjust k′

.

2. The method of claim 1, wherein said quality parameter is utilized in said transmit unit to adjust the coding of said coding unit.

3. The method of claim 1, wherein said coding unit is selected from the group consisting of space-time coders, space-frequency coders, adaptive modulation rate coders.

4. The method of claim 3, wherein said space-time coders and said space-frequency coders use different coding and modulation rates.

5. The method of claim 1, further comprising the step of receive processing said receive signals RS_j to reproduce said spatial-multiplexed streams SM_i.

6. The method of claim 5, wherein said quality parameter is obtained from said receive processed spatial-multiplexed streams SM_i.

7. The method of claim 6, wherein said quality parameter is derived by a statistical unit.

8. The method of claim 6, wherein said quality parameter is selected from the group consisting of signal-to-interference noise ratio, signal-to-noise ratio, power level, level crossing rate, level crossing duration.

9. The method of claim 1, further comprising the steps of processing said receive signals RS_j to reconstitute said data and obtaining said quality parameter from said data.

10. The method of claim 9, wherein said quality parameter is selected from the group consisting of bit-error-rate and packet error-rate.

11. The method of claim 1, wherein said mapping step further comprises a transmit processing step by a transmit processing block and said quality parameter is used for adjusting the transmit processing of said transmit processing block.

12. The method of claim 1, wherein said quality parameter is fed back to said transmit unit.

13. The method of claim 1, wherein said step of processing said data comprises a technique selected from the group consisting of adaptive modulation, adaptive coding, Space-Time coding, and Space-Frequency coding.

14. The method of claim 1, wherein said transmit signals TS_p are formatted in accordance with at least one multiple access technique selected from the group consisting of TDMA, FDMA, CDMA, OFDMA.

15. The method of claim 1, wherein said communication parameter is selected from the group consisting of data capacity, signal quality and throughput.

16. The method of claim 1, wherein said receive unit and said transmit unit belong to a cellular communication system.

17. The method of claim 16, used in the downlink of said cellular communication system.

18. The method of claim 16, used in the uplink of said cellular communication system.

19. A communication system with an adaptively maximized communication parameter of a channel in which data is transmitted between a transmit unit having a number M of transmit antennas and a receive unit having a number N of receive antennas, said transmit unit comprising:

a) processing means for processing said data to produce parallel spatial-multiplexed streams SM_i, where i=1 . . . k;

b) antenna mapping means for converting said spatial-multiplexed streams SM_i to transmit signals TS_p, where p=1 . . . M, and transmitting said transmit signals TS_p from said M transmit antennas via said channel;

said receive unit receiving receive signals RS_j, where j=1 . . . N, and said communication system comprising;

a) means for assessing a quality parameter of said receive signals RS_j;

b) means for adjusting k based on said quality parameter to maximize said communication parameter of said channel; and

c) an adaptive controller in communication with said processing means and said antenna mapping means, said adaptive controller adjusting said processing means and said antenna mapping means based on said quality parameter.

20. The communication system of claim 19, wherein said means for assessing said quality parameter comprises a statistical unit.

21. The communication system of claim 19, wherein said means for assessing said quality parameter is located in said receive unit.

22. The communication system of claim 19, wherein said means for assessing said quality parameter is located in said transmit unit.

23. The communication system of claim 19, further comprising a coding unit in said transmit unit for processing said spatial-multiplexed streams SM_i to produce coded streams CS_h, where h=1 . . . k′

.

24. The communication system of claim 23, wherein said means for adjusting k further comprises a mechanism for adjusting k′

.

25. The communication system of claim 23, wherein said coding unit is selected from the group consisting of space-time coders, space-frequency coders, adaptive modulation rate coders.

26. The communication system of claim 23, further comprising a database of codes and antenna mapping parameters in communication with said coding unit and said antenna mapping means.

27. The communication system of claim 23, further comprising an adaptive controller in communication with said processing means, said coding unit and said antenna mapping means, said adaptive controller adjusting said processing means, said coding unit and said antenna mapping means based on said quality parameter.

28. The communication system of claim 19, wherein said means for adjusting k is located in said transmit unit.

29. The communication system of claim 19, said communication system operating in accordance with at least one multiple access technique selected from the group consisting of TDMA, FDMA, CDMA, OFDMA.

30. The communication system of claim 19, wherein said communication system is a cellular communication system.

31. The communication system of claim 19 employing multi-carrier modulation.