Multiple modulation schemes in single rate layering wireless communication systems

• US 20060014499A1
• Filed: 06/16/2005
• Published: 01/19/2006
• Est. Priority Date: 07/16/2004
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gorokhov, Alexei, Agrawal, Avneesh, Kadous, Tamer, Gore, Dhananjay
• Granted Patent: US 8,457,152 B2
• Time in Patent Office: Days
• US Class Current: 455/102
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/005 Iterative decoding, including iteration between signal detection and decoding operation
• CPC Class Codes: H04L 1/06 using space diversity

Abstract

A MIMO communication system is adapted to encode multiple data streams at the same adaptable rate. Accordingly, the set of all possible modulation/rate combinations to all modulations with common rates is decreased thus resulting in the reduction of the number of possible packet formats carrying the data streams. Rate prediction is made more error-resilient, in part, due to the averaging over all information rates. Furthermore, the signaling overhead of the packets is reduced. Therefore, the tradeoff between the desired transmission rate granularity on the one hand, and robustness/signaling overhead on the other hand, is controlled by adjusting the coding rate.

Claims

1. A wireless communication device comprising:

a plurality of encoders each adapted to receive and encode a different one of a plurality of data segments to generate an encoded data segment;

wherein the plurality of encoders are configured to encode the data segments they receive at a same rate for simultaneously encoded data segments;

a plurality of modulators each adapted to receive and modulate a different one of the plurality of encoded data segments to generate a modulated data segment according to a modulation technique, wherein at least two of the modulators utilize different modulation techniques for simultaneously modulated data segments; and

a plurality of transmitters each adapted to receive and process a different one of the transformed signals and to deliver the processed signal to a different one of a plurality of associated transmit antennas for transmission.

2. The wireless communication device of claim 1, further comprising a beamforming block coupled between the plurality of modulators and the plurality of front-ends.

3. The transmitter of claim 1 wherein the data segments are parts of a same data stream.

4. The transmitter of claim 1 wherein a subset of the plurality of data segments is a part of different data streams.

5. The transmitter of claim 1 wherein each of the plurality modulators is configured to modulate the data segment it receives using a different modulation technique for simultaneously modulated data segments.

6. The transmitter of claim 1 wherein each transmit transmitter is configured to convert the transformed signal it receives from a baseband signal to an RF signal.

7. The transmitter of claim 6 wherein each transmit transmitter is further configured to filter, amplify and convert to an analog signal the digital signal that it receives.

8. A wireless communication device comprising:

a plurality of receivers each adapted to receive a first plurality of signals transmitted by a plurality of transmit antennas;

a combiner configured to receive the signals delivered by the plurality of receivers and to recover a plurality of modulated data segments;

a plurality of demodulators each adapted to receive and demodulate a different one of the recovered data segments and to generate a demodulated data segment, wherein the demodulators demodulate at least some of the recovered data segments according to different demodulation techniques; and

a plurality of decoders each adapted to receive and decode a different one of the plurality of demodulated data segments to generate a decoded data segment.

9. The receiver of claim 8 wherein said receive combiner is a linear filter.

10. The receiver of claim 9 wherein said linear filter is configured to perform linear minimum mean-square error filtering operation on the received signals.

11. The receiver of claim 8 wherein said receiver further comprises:

a plurality of encoders each coupled to a different one of the decoders and adapted to receive and encode a different one of the decoded data segments to generate an encoded canceling signal.

12. The receiver of claim 11 wherein said receiver further comprises:

a plurality of modulators each adapted to receive and encode a different one of the encoded canceling signals to generate a modulated encoded canceling signal.

13. The receiver of claim 12 wherein said combiner is further configured to modify each of the recovered data segments by a corresponding one of the modulated encoded canceling signals.

14. A method comprising:

encoding each of a plurality of data segments at a same rate to generate a plurality of encoded data segments;

modulating each of the plurality of encoded data segments to generate a plurality of modulated data segments, wherein at least two of the plurality encoded data segments are modulated according to different modulation techniques; and

transmitting the plurality of processed signals via a plurality of associated transmit antennas.

15. The method of claim 14 further comprising eigenbeamforming the modulated data segments prior to transmitting.

16. The method of claim 14 wherein the plurality of data segments are parts of the same data stream.

17. The method of claim 14 wherein a subset of the plurality of data segments is a part of a different data stream.

18. The method of claim 14 wherein modulating comprises modulating each of the plurality of encoded data segments according to different modulation techniques.

19. The method of claim 14 wherein processing each of the plurality of transformed signals comprises converting each of the transformed signals from a baseband signal to an RF signal.

20. The method of claim 19 wherein processing each of the plurality of transformed signals further comprises:

filtering each of the transformed signals,

amplifying each of the transformed signals; and

converting each of the transformed signals from a digital signal to an analog signal.

21. A method comprising:

receiving a first plurality of signals transmitted by a plurality of transmit antennas;

wherein the first plurality of signals is generated by transforming a second plurality of signals before transmission;

recovering a plurality of data segments from the first plurality of received signals;

demodulating each of the plurality of recovered data segments, wherein the at least some of the recovered data segments are demodulated according to different demodulation techniques; and

decoding each of the plurality of demodulated data segments.

22. The method of claim 21 wherein the step of recovering further comprises performing a linear filtering operation on the first plurality of signals.

23. The method of claim 22 wherein the step of performing a linear filtering operation further comprises performing a linear minimum mean-square error filtering operation.

24. The method of claim 21 further comprising:

encoding each of the decoded data segments to generate an encoded canceling signal.

25. The method of claim 24 further comprising:

modulating each of the encoded canceling signals to generate a plurality of modulated encoded canceling signals.

26. The method of claim 25 further comprising:

modifying each of the plurality of recovered data segments by a corresponding one of the plurality of modulated encoded canceling signals.

27. A transmitter comprising:

means for receiving and encoding each of a plurality of data segments at a same rate to generate a plurality of encoded data segments;

means for modulating at least two of the plurality of encoded data segments using different modulation techniques to generate a plurality of modulated data segments; and

means for transmitting the processed signals via a plurality of associated transmit antennas.

28. The transmitter of claim 27 further comprising:

means for applying eigenvectors to the plurality of modulated data segments.

29. The transmitter of claim 27 wherein the plurality of data segments are parts of the same data stream.

30. The transmitter of claim 27 wherein a subset of the plurality of data segments is a part of a different data stream

31. The transmitter of claim 27 further comprising:

means for modulating each of the plurality of encoded data using a different modulation technique.

32. The transmitter of claim 27 further comprising:

means for converting each of the transformed signals from a baseband signal to an RF signal.

33. The transmitter of claim 32 further comprising:

means for filtering each of the transformed signals;

means for amplifying each of the transformed signals; and

means for converting each of the transformed signals from a digital signal to an analog signal.