Access point with simultaneous downlink transmission of independent data for multiple client stations

• US 8,144,647 B2
• Filed: 07/18/2008
• Issued: 03/27/2012
• Est. Priority Date: 07/18/2007
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: Nabar, Rohit U., Zhang, Hongyuan, Lou, Hui-Ling
• Primary Examiner(s): PHUNKULH, BOB A
• Application Number:
  US12/175,526
• Publication Number:
  US 20090022128A1
• Time in Patent Office: 1,348 Days
• Field of Search: None
• US Class Current: 370/328
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0697 using spatial multiplexing
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 65/65 Network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP]
• CPC Class Codes: H04W 28/0215 based on user or device properties, e.g. MTC-capable devices services for machine-to-machine communication [M2M] or machine type communication [MTC] H04W4/70; wireless resource selection or allocation plan definition based on terminal or device properties H04W72/51
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/51 based on terminal or device properties
• CPC Class Codes: H04W 74/06 using polling

Abstract

A wireless network device comprises R modulation modules that receive R independent data streams, that modulate the R independent data streams, and that apply a multiplexing matrix to generate M modulated and multiplexed data streams, respectively, where R and M are integers greater than one. M summing modules sum portions of each of the M modulated and multiplexed data streams to generate M transmit data streams. M transmitters simultaneously transmit the M transmit data streams during a simultaneous downlink transmission (SDT) period.

Claims

1. A wireless network device comprising:

R modulation modules configured to (i) receive R independent data streams, (ii) modulate the R independent data streams, and (iii) apply a multiplexing matrix to generate M modulated and multiplexed data streams, respectively, where R and M are integers greater than one;

M summing modules configured to sum portions of each of the M modulated and multiplexed data streams to generate M transmit data streams;

M transmitters configured to simultaneously transmit the M transmit data streams during a simultaneous downlink transmission period to R client stations; and

M receivers configured to respectively receive R acknowledgements from the R client stations during R allocated time slots of the simultaneous downlink transmission period.

2. The wireless network device of claim 1, wherein the wireless network device is configured to transmit (i) a first one of the M transmit data streams to at least two of the R client stations and (ii) a second one of the M transmit data streams to at least one of the R client stations.

3. The wireless network device of claim 1, wherein one of the M transmitters is configured to transmit a signal vector s, where:

4. The wireless network device of claim 1, wherein the R independent data streams are arranged as subframes, frames, or packets.

5. A wireless network device comprising:

R modulation modules configured to (i) receive R independent data streams, (ii) modulate the R independent data streams, and (iii) apply a multiplexing matrix to generate M modulated and multiplexed data streams, respectively, where R and M are integers greater than one;

wherein each of the R modulation modules comprises

a spatial mapping module configured to (i) perform spatial mapping of one of the R independent data streams and (ii) generate M spatial data streams,

M modulation mapping modules configured to (i) receive respective ones of the M spatial data streams and (ii) output M sets of tones,

a multiplexing matrix module configured to apply the multiplexing matrix to the M sets of tones, and

an inverse Fast Fourier Transform module communication with an output of the multiplexing matrix module;

M summing modules configured to sum portions of each of the M modulated and multiplexed data streams to generate M transmit data streams; and

M transmitters configured to simultaneously transmit the M transmit data streams during a simultaneous downlink transmission period.

6. The wireless network device of claim 5, wherein each of the M modulation mapping modules comprises a quadrature amplitude modulation module.

7. A wireless network device comprising:

R modulation modules configured to (i) receive R independent data streams, (ii) modulate the R independent data streams, and (iii) apply a multiplexing matrix to generate M modulated and multiplexed data streams, respectively, where R and M are integers greater than one;

M summing modules configured to sum portions of each of the M modulated and multiplexed data streams to generate M transmit data streams;

M transmitters configured to simultaneously transmit the M transmit data streams during a simultaneous downlink transmission period to R client stations; and

a multiplexing matrix module configured to generate a respective multiplexing matrix based on channel conditions between the wireless network device and each of the R client stations.

8. The wireless network device of claim 7, wherein the multiplexing matrix module is configured to determine a multiplexing matrix for one of the R client stations by minimizing signal energy of signals sent to others of the R client stations.

9. The wireless network device of claim 7, wherein the multiplexing matrix module is configured to determine a multiplexing matrix for one of the R client stations by maximizing a minimum signal-to-interference and noise ratio for the R client stations.

10. The wireless network device of claim 8, wherein the multiplexing matrix module is configured to determine the multiplexing matrix based on a signal-to-interference and noise ratio of the R client stations.

11. The wireless network device of claim 7, wherein the multiplexing matrix module is configured to adjust at least one of amplitude or phase for tones of the M transmit data streams.

12. The wireless network device of claim 7, further comprising a receiver configured to receive channel state information from the R client stations.

13. The wireless network device of claim 7, further comprising:

a receiver; and

a channel condition estimator configured to estimate channel state information based on signals received from the R client stations.

14. A method comprising:

receiving R independent data streams;

modulating the R independent data streams;

applying a multiplexing matrix to generate M modulated and multiplexed data streams, respectively, where R and M are integers greater than one;

summing portions of each of the M modulated and multiplexed data streams to generate M transmit data streams;

simultaneously transmitting the M transmit data streams during a simultaneous downlink transmission period to R client stations; and

receiving R acknowledgements from the R client stations during R allocated time slots of the simultaneous downlink transmission period.

15. The method of claim 14, further comprising transmitting;

a first one of the M transmit data streams to at least two of the R client stations; and

a second one of the M transmit data streams to at least one the R client stations.

16. The method of claim 14, further comprising:

performing spatial mapping of one of the R independent data streams and generating M spatial data streams;

receiving respective ones of the M spatial data streams and outputting M sets of tones;

applying the multiplexing matrix to the M sets of tones; and

performing an inverse Fast Fourier Transform.

17. The method of claim 16, wherein each of the M modulation mapping modules comprises a quadrature amplitude modulation module.

18. The method of claim 14, further comprising generating a respective multiplexing matrix based on channel conditions between a wireless network device and each of the R client stations.

19. The method of claim 18, further comprising determining a multiplexing matrix for one of the R client stations by minimizing signal energy of signals sent to others of the R client stations.

20. The method of claim 18, further comprising determining a multiplexing matrix for one of the R client stations by maximizing a minimum signal-to-interference and noise ratio for the R client stations.

21. The method of claim 18, further comprising determining the multiplexing matrix based on a signal-to-interference and noise ratio of the R client stations.

22. The method of claim 18, further comprising receiving channel state information from the R client stations.

23. The method of claim 18, further comprising estimating channel state information based on signals received from the R client stations.

24. The method of claim 14, further comprising adjusting at least one of amplitude or phase for tones of the M transmit data streams.

25. The method of claim 14, further comprising transmitting a signal vector s, where:

26. The method of claim 14, wherein the R independent data streams are arranged as subframes, frames, or packets.