Adaptive MIMO systems

• US 20050237971A1
• Filed: 01/13/2005
• Published: 10/27/2005
• Est. Priority Date: 02/23/2004
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Skraparlis, Dimitrios
• Application Number:
  US11/033,631
• Publication Number:
  US 20050237971A1
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/043 using best eigenmode, e.g. beam forming or beam steering
• CPC Class Codes: H04B 7/0439 utilizing channel inversion
• CPC Class Codes: H04B 7/0443 utilizing "waterfilling" technique
• CPC Class Codes: H04B 7/0465 taking power constraints at power amplifier or emission constraints, e.g. constant modulus, into account
• CPC Class Codes: H04B 7/0619 using feedback from receiving side feedback signaling for adaptive modulation/coding H04L1/0001
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas space-time coding H04L1/0618
• CPC Class Codes: H04B 7/0891 Space-time diversity rake receivers H04B1/7115; space-time decoding H04L1/0631
• CPC Class Codes: H04L 1/0618 Space-time coding
• CPC Class Codes: H04L 25/0246 with factorisation
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity

Abstract

This invention is generally concerned with apparatus, methods and processor control code for MIMO (multiple-input multiple-output) communications systems. An adaptive MIMO communications system comprising a MIMO transmitter and a MIMO receiver and having a feedback path from said receiver to said transmitter, said MIMO transmitter including a receiver to receive a feedback signal from said receiver sent via said feedback path and a controller responsive to said feedback signal to configure a MIMO transmission from said transmitter to said receiver, said MIMO receiver being configured to receive said MIMO transmission; and wherein said MIMO receiver includes a decision module, said decision module having a power indicating input to input a signal indicating a desired receiver power consumption, and an output for sending a MIMO configuration signal to said MIMO transmitter, said decision module being configured to determine a MIMO transmission configuration responsive to said power indicating input and to output a MIMO configuration signal for feedback to said transmitter to configure said transmitter in accordance with said determination.

Claims

1. An adaptive MIMO communications system comprising a MIMO transmitter and a MIMO receiver and having a feedback path from said receiver to said transmitter,

said MIMO transmitter including a receiver to receive a feedback signal from said receiver sent via said feedback path and a controller responsive to said feedback signal to configure a MIMO transmission from said transmitter to said receiver;

said MIMO receiver being configured to receive said MIMO transmission; and

wherein said MIMO receiver includes a decision module, said decision module having a power indicating input to input a signal indicating a desired receiver power consumption, and an output for sending a MIMO configuration signal to said MIMO transmitter, said decision module being configured to determine a MIMO transmission configuration responsive to said power indicating input and to output a MIMO configuration signal for feedback to said transmitter to configure said transmitter in accordance with said determination.

2. An adaptive MIMO system as claimed in claim 1 wherein said receiver further includes a communications quality of service (QoS) measuring system having a measured QoS signal output, and wherein said decision module includes a measured QoS input from said measured QoS output, and a desired QoS input for inputting a signal indicating a desired QoS, and wherein said decision module is further configured to input.

4. An adaptive MIMO system as claimed in claim 2 wherein said desired QoS signal comprises a signal indicating into which one of a plurality of categories the data to be transmitted falls.

5. An adaptive MIMO system as claimed in claim 4 wherein said plurality of categories of data define a plurality of minimum acceptable QoS levels.

6. An adaptive MIMO system as claimed in claim 4 wherein said plurality of categories of data define a plurality of maximum data transmission latencies.

8. An adaptive MIMO system as claimed in claim 6 wherein said plurality of categories of data define a plurality of minimum acceptable QoS levels.

10. An adaptive MIMO system as claimed in claim 2 wherein said measured QoS signal comprises a block error rate signal.

11. An adaptive MIMO system as claimed in claim 2 wherein said transmitter includes a data compression module, responsive to said feedback signal, for outputting compressed audio and/or video data for transmission, wherein said decision module is configured to output a MIMO configuration signal indicating that a reduced data rate is to be employed when said measured QoS is less than said desired QoS, and wherein said transmitter is configured control said data compression module responsive to said rate reduction signal to provide a reduced data rate output.

12. An adaptive MIMO system as claimed in claim 1 wherein said decision module is further configured to determine a said MIMO transmission configuration responsive to a previously determined MIMO transmission configuration.

13. An adaptive MIMO system as claimed in claim 1 wherein said receiver further includes a channel metric computation module having a channel metric output, and wherein said decision module is further configured to determine a said MIMO transmission configuration responsive to said channel metric output.

14. An adaptive MIMO system as claimed in claim 13 wherein said channel metric computation module has a time determining input, wherein said channel metric is calculated over a period of time responsive to said time determining input, and wherein said decision module is configured to provide a channel type signal to said time determining input, said channel type signal indicating one of a plurality of categories of channel type into which a MIMO channel between said MIMO transmitter and said MIMO receiver falls.

15. An adaptive MIMO system as claimed in claim 13 wherein said receiver is further configured to estimate a MIMO channel response matrix for decoding a received signal and for computing a said channel metric.

16. An adaptive MIMO system as claimed in claim 15 wherein said receiver is configured to determine a decomposition of said channel response matrix, for computing a said channel metric and/or decoding a received signal, in parallel with said channel response estimation.

17. An adaptive MIMO system as claimed in claim 15 wherein said receiver is configured to determine a decomposition of said channel response matrix, for computing a said channel metric and for decoding a received signal using shared computational resources.

18. An adaptive MIMO system as claimed in claim 1 wherein said MIMO configuration signal comprises a signal indicating a MIMO transmission scheme or algorithm and/or a constellation size or modulation type.

19. An adaptive MIMO system as claimed in claim 2 wherein said decision module comprises a look-up table to provide data indicating a preferred MIMO configuration and a decision modifier to modify said preferred MIMO configuration responsive to said measured QoS signal to provide a modified MIMO configuration for outputting as a said MIMO configuration signal.

22. A MIMO receiver as recited in claim 1.

26. A MIMO transmitter as recited in claim 1.

30. Computer program code, in particular on a carrier, to when running implement the decision module of claim 1.

3. An adaptive MIMO communications system comprising a MIMO transmitter and a MIMO receiver and having a feedback path from said receiver to said transmitter,

said MIMO transmitter including a receiver to receive a feedback signal from said receiver sent via said feedback path and a controller responsive to said feedback signal to configure a MIMO transmission from said transmitter to said receiver;

said MIMO receiver being configured to receive said MIMO transmission; and

wherein said MIMO receiver includes a communications quality of service (QoS) measuring system having measured QoS signal output, and a decision module, said decision module having a first, measured QoS input and a second input to input a signal indicating a desired QoS, and an output to output a MIMO configuration signal, and wherein said decision module is configured to input a said desired QoS signal, determine a first MIMO transmission configuration responsive to said desired QoS signal, output a first MIMO configuration signal for feedback to said transmitter to configure said transmitter in accordance with said determination, input a said measured QoS signal, determine a second MIMO transmission configuration responsive to said measured QoS signal, and output a second MIMO configuration signal for feedback to said transmitter to configure said transmitter in accordance with said second determination.

7. An adaptive MIMO system as claimed in claim 3 wherein said desired QoS signal comprises a signal indicating into which one of a plurality of categories the data to be transmitted falls.

9. An adaptive MIMO system as claimed in claim 7 wherein said plurality of categories of data define a plurality of maximum data transmission latencies.

23. A MIMO receiver as recited in claim 3.

27. A MIMO transmitter as recited in claim 3.

20. An adaptive MIMO communications system comprising a MIMO transmitter and a MIMO receiver and having a feedback path from said receiver to said transmitter,

said MIMO transmitter including a receiver to receive a feedback signal from said receiver sent via said feedback path and a controller responsive to said feedback signal to configure a MIMO transmission from said transmitter to said receiver;

said MIMO receiver being configured to receive said MIMO transmission; and

wherein said MIMO receiver includes a channel metric computation module having a channel metric output and a decision module, said decision module having a channel metric input and an output for sending a MIMO configuration signal to said MIMO transmitter, said decision module being configured to determine a MIMO transmission configuration responsive to said channel metric input and to output a MIMO configuration signal for feedback to said transmitter to configure said transmitter in accordance with said determination;

wherein said receiver is further configured to estimate a MIMO channel response matrix for decoding a received signal and for computing a said channel metric, and to determine a decomposition of said channel response matrix, for computing a said channel metric and/or decoding a received signal, in parallel with said channel response estimation.

24. A MIMO receiver as recited in claim 20.

28. A MIMO transmitter as recited in claim 20.

21. An adaptive MIMO communications system comprising a MIMO transmitter and a MIMO receiver and having a feedback path from said receiver to said transmitter,

said MIMO transmitter including a receiver to receive a feedback signal from said receiver sent via said feedback path and a controller responsive to said feedback signal to configure a MIMO transmission from said transmitter to said receiver;

said MIMO receiver being configured to receive said MIMO transmission; and

wherein said MIMO receiver includes channel metric computation module having a channel metric output and a decision module, said decision module having a channel metric input and an output for sending a MIMO configuration signal to said MIMO transmitter, said decision module being configured to determine a MIMO transmission configuration responsive to said channel metric input and to output a MIMO configuration signal for feedback to said transmitter to configure said transmitter in accordance with said determination;

wherein said receiver is further configured to estimate a MIMO channel response matrix for decoding a received signal and for computing a said channel metric, and to determine a decomposition of said channel response matrix, for computing a said channel metric and for decoding a received signal using shared computational resources.

25. A MIMO receiver as recited in claim 21.

29. A MIMO transmitter as recited in claim 21.

31. A MIMO receiver for receiving a MIMO transmission, the receiver comprising:

a MIMO channel matrix estimator to estimate a MIMO channel response matrix for decoding a received signal; and

a matrix decomposition module to determine a decomposition of said channel response matrix for decoding a received signal; and

wherein said receiver is configured to estimate said channel response in parallel with said channel matrix response decomposition determination.

32. A method of configuring an adaptive MIMO communications system comprising a MIMO transmitter and a MIMO receiver and having a feedback path from said receiver to said transmitter, said MIMO transmitter including a receiver to receive a feedback signal from said receiver sent via said feedback path and a controller responsive to said feedback signal to configure a MIMO transmission from said transmitter to said receiver, said MIMO receiver being configured to receive said MIMO transmission, the method comprising:

inputting a signal indicating a desired receiver power consumption;

determining a MIMO transmission configuration responsive to said power indicating input; and

outputting a MIMO configuration signal for feedback to said transmitter to configure said transmitter in accordance with said determination.

33. A method of configuring an adaptive MIMO communications system comprising a MIMO transmitter and a MIMO receiver and having a feedback path from said receiver to said transmitter, said MIMO transmitter including a receiver to receive a feedback signal from said receiver sent via said feedback path and a controller responsive to said feedback signal to configure a MIMO transmission from said transmitter to said receiver, said MIMO receiver being configured to receive said MIMO transmission, the method comprising:

inputting a desired communications quality of service (QoS) signal;

determining a first MIMO transmission configuration responsive to said desired QoS signal;

outputting said first MIMO configuration signal for feedback to said transmitter to configure said transmitter in accordance with said determination;

measuring a communications quality of service (QoS);

determining a second MIMO transmission configuration responsive to said measured QoS; and

outputting a second MIMO configuration signal for feedback to said transmitter to configure said transmitter in accordance with said second determination.