System and method for distributed input-distributed output wireless communications

• US 7,418,053 B2
• Filed: 07/30/2004
• Issued: 08/26/2008
• Est. Priority Date: 07/30/2004
• Status: Active Grant

• Current Assignee: Rearden, LLC
• Original Assignee: Rearden, LLC
• Inventors: Perlman, Stephen G., Cotter, Tim
• Primary Examiner(s): Ha; Dac V
• Application Number:
  US10/902,978
• Publication Number:
  US 20060023803A1
• Time in Patent Office: 1,488 Days
• Field of Search: 375/219, 375/222, 375/146, 375/147, 375/260, 375/267, 375/299, 375/347, 370/208, 370/252, 370/278, 370/282, 370/464, 370/465, 455/101
• US Class Current: 375/267
• CPC Class Codes: H04B 7/0684 using different training sequences per antenna
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 2025/03414 Multicarrier
• CPC Class Codes: H04L 2025/0377 during the reception of training signals
• CPC Class Codes: H04L 2025/03802 Signalling on the reverse channel
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 25/03891 Spatial equalizers MIMO diversity systems H04B7/0413

Abstract

A method is described comprising: transmitting a training signal from each antenna of a base station to each of a plurality of client devices, each of the client devices analyzing each training signal to generate channel characterization data, and transmitting the channel characterization data back to the base station; storing the channel characterization data for each of the plurality of client devices; receiving data to be transmitted to each of the client devices; and precoding the data using the channel characterization data associated with each respective client device to generate precoded data signals for each antenna of the base station; and transmitting the precoded data signals through each antenna of the base station to each respective client device.

Claims

1. A method comprising:

transmitting a training signal from each antenna of a base station to each of a plurality of client devices, each of the client devices independently analyzing each training signal to generate channel characterization data, wherein for a base station having N antennas transmitting to M client devices the channel characterization data comprises at least N * M components, each component defining a channel characterization between one of the N antennas and one of the M client devices;

transmitting the channel characterization data including the N * M components back to the base station;

storing the channel characterization data including the N * M components associated with each antenna/client device combinations;

receiving data to be transmitted to each of the client devices; and

precoding the data using the channel characterization data including each of the N * M components associated with each respective antenna/client device combination to generate precoded data signals for each antenna/client device combination; and

transmitting the precoded data signals through each antenna of the base station to each respective client device.

2. The method of claim 1,

wherein the channel characterization data for each client device is generated by each client by independently processing and characterizing the training signal from each antenna of the base station.

3. The method of claim 2, further comprising:

periodically sending a new training signal through each antenna of the base station to each client device; and

receiving new channel characterization data for each client device, the channel characterization data for each client device having been generated by each client device having independently processed and characterized the new training signal from each antenna of the base station; and

storing the new channel characterization data including the N * M components for each client device.

4. The method of claim 3, wherein the new training signal is interleaved within preceded data signals.

5. The method of claim 1 wherein the client devices comprise wireless data processing devices with cellular telephony capabilities.

6. The method of claim 5, further comprising:

requesting the training signal from each client device.

7. The method of claim 5, further comprising:

continuously receiving a new training signal from each client device.

8. The method of claim 1, wherein transmitting each respective preceded data signal comprises:

a first transmission to a first selected group within the plurality of client devices; and

a second transmission to a second selected group within the plurality of client devices, the first and second selected group defined such as to allocate bandwidth in a desired fashion.

9. The method of claim 8, wherein the desired fashion is any combination selected from the group consisting of allocating bandwidth evenly, allocating bandwidth according to priority, allocating bandwidth based on a current load required by a client device, and allocating bandwidth to avoid multiple client devices in close proximity to each other.

10. The method of claim 1, wherein the base station communicates with two client devices concurrently using multiplexing techniques.

11. The method of claim 1, wherein a client device has multiple antennas, each antenna treated as a separate client device.

12. The method of claim 1, further comprising:

routing the input data into separate bit streams to respective antennas of the base station, each separate bit stream intended for a respective client device;

storing the channel characterization data as a channel characterization matrix; and

multiplying each separate bit stream by the inverse of the channel characterization matrix to generate the precoded data signals.

13. The system of claim 1 wherein each client device comprises a single antenna.

14. The system as in claim 1 further comprising:

modulating the precoded data signals using a specified type of signal modulation.

15. The system as in claim 14 wherein the specified type of signal modulation is selected from the group consisting of quadrature amplitude modulation (QAM), differential phase shift keying (DPSK) and orthogonal frequency division multiplexing (OFDM).

16. The system as in claim 14 further comprising:

encoding the precoded data signals using a specified type of error correction code.

17. The system as in claim 16 wherein the specified type of error correction code is selected from the group consisting of Reed Solomon, Viterbi and Turbo coding.

18. The method of claim 1 wherein the training signal from each antenna of the base station is transmitted to each of the plurality of client devices through a Near Vertical Incidence Skywave (“

NVIS”

) communication link.

19. The method as in claim 18 wherein the channel characterization data is transmitted from each of the clients to the base station through the NVIS communication link.

20. The method as in claim 19 wherein the precoded data signals are transmitted from the antennas of the base station to the plurality of client devices through the NVIS communication link.

21. The method as in claim 20 wherein the precoded data signals are transmitted a carrier frequency at or below 23 MHz.

22. A system comprising:

a plurality of client devices;

a base station; and

a plurality of antennas of the base station each antenna transmitting a training signal to each of a plurality of client devices, each of the client devices independently analyzing its respective training signals to generate channel characterization data, wherein for a base station having N antennas transmitting to M client devices, the channel characterization data comprises at least N * M components, each component defining a channel characterization between one of the N antennas and one of the M client devices wherein each client device transmits the channel characterization data including the N * M components back to the base station, wherein the base station stores the channel characterization data including the N * M components associated with each antenna/client device combination, and wherein the base station precodes the data using the channel characterization data including each of the N * M components associated with each respective antenna/client device combination to generate precoded data signals for each antenna/client device combination; and

wherein each antenna of the base station transmits a respective precoded data signal through each antenna to each respective client device.

23. The system of claim 22, wherein the channel characterization data is generated by each client device having independently processed and characterized a training signal transmitted by each antenna of the base station to each client device.

24. The system of claim 22, wherein the channel characterization data is generated by the base station having processed and characterized a training signal transmitted from each client device to each antenna of the base station.

25. The system of claim 22, wherein synchronization techniques are employed to ensure less than a certain number of transmissions and receptions at a given time, such as to not exceed total channel bandwidth.