Wireless precoding methods

• US 20060029157A1
• Filed: 08/09/2005
• Published: 02/09/2006
• Est. Priority Date: 08/09/2004
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Texas Instruments, Inc.
• Inventors: Onggosanusi, Eko N., Dabak, Anand G.
• Granted Patent: US 8,023,589 B2
• Time in Patent Office: Days
• US Class Current: 375/299
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0619 using feedback from receiving side feedback signaling for adaptive modulation/coding H04L1/0001
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601

Abstract

Various wireless precoding systems and methods are presented. In some embodiments, a wireless transmitter comprises an antenna preceding block, a transform block, and multiple transmit antennas. The antenna preceding block receives frequency coefficients from multiple data streams and distributes the frequency coefficients across multiple transmit signals in accordance with frequency-dependent matrices. The transform block transforms the precoded frequency coefficients into multiple time domain transmit signals to be transmitted by the multiple antennas. The frequency coefficients from multiple data streams may be partitioned into tone groups, and all the frequency coefficients from a given tone group may be redistributed in accordance with a single matrix for that tone group. In some implementations, the frequency coefficients within a tone group for a given data stream may also be precoded. In some alternative embodiments, tone group preceding may be employed in a single channel system.

Claims

1. A wireless transmitter that comprises:

an antenna preceding block that receives frequency coefficients from multiple data streams and distributes the frequency coefficients across multiple transmit signals in accordance with frequency-dependent matrices;

one or more transform blocks that transform transmit signal frequency coefficients into multiple time domain transmit signals; and

multiple transmit antennas each coupled to receive one of the multiple time domain transmit signals.

2. The transmitter of claim 1, wherein the frequency coefficients from multiple data streams are partitioned into tone groups, and wherein the antenna precoding block distributes all frequency coefficients from a given tone group in accordance with a single matrix for that tone group.

3. The transmitter of claim 1, wherein the frequency dependent matrices are based on a dynamically estimated channel response.

4. The transmitter of claim 1, wherein the frequency coefficients from multiple data streams are partitioned into tone groups, and wherein the transmitter further comprises:

at least one tone group preceding block that receives bits allocated to the tone groups for one of the multiple data streams and distributes the bits of each tone group across multiple frequency coefficients of that tone group in accordance with a precoding matrix for that tone group.

5. The transmitter of claim 4, wherein the tone group precoding matrices are determined from a channel estimation.

6. The transmitter of claim 1, further comprising a channel estimation and matrix selection block that is coupled to a receiver to determine the estimated channel response and is further configured to determine the frequency-dependent precoding matrices from the estimated channel response.

7. A wireless communication method that comprises:

receiving multiple data streams;

allocating bits from the data streams as frequency coefficients for orthogonal frequency division multiplexing (OFDM) tones;

precoding the frequency coefficients to distribute their energy across multiple transmit signals in accordance with frequency-dependent preceding matrices;

transforming frequency coefficients for the multiple transmit signals into multiple time domain transmit signals; and

transmitting each time domain transmit signal on a respective transmit antenna.

8. The method of claim 7, wherein the OFDM tones are partitioned into tone groups, and wherein frequency coefficients within each tone group are precoded with a precoding matrix for that tone group.

9. The method of claim 7, further comprising:

determining an estimated channel transfer function; and

selecting the frequency-dependent precoding matrices based on the estimated channel transfer function.

10. The method of claim 7, wherein the OFDM tones are partitioned into tone groups, and wherein said preceding includes distributing frequency coefficient energy across multiple OFDM tones in a tone group in accordance with a tone group precoding matrix.

11. The method of claim 10, further comprising:

determining the tone group preceding matrix from an estimated channel transfer function.

12. A wireless transmitter that comprises:

a combined tone group and antenna precoding block that receives frequency coefficients for multiple data streams and distributes the frequency coefficients across multiple tones within each tone group and across multiple transmit signals in accordance with set of tone-group dependent precoding matrices;

a transform block that transforms frequency coefficients of the multiple transmit signals into multiple time domain transmit signals; and

multiple transmit antennas each coupled to receive one of the multiple time domain transmit signals.

13. The transmitter of claim 12, wherein the tone-group dependent precoding matrices are dynamically determined from estimated channel responses.

14. The transmitter of claim 12, further comprising a channel estimation and matrix selection block that is coupled to a receiver to determine the estimated channel response and is configured to determine the set of tone-group dependent precoding matrices from the estimated channel response.

15. A wireless transmitter that comprises:

a preceding block that receives frequency coefficients representing a data stream, wherein the frequency coefficients are partitioned into tone groups, and wherein the precoding block redistributes energy of frequency coefficients within each tone group in accordance with a set of tone group preceding matrices that are dynamically determined based on an estimated channel response;

a transform block that transforms precoded frequency coefficients from the preceding block into a time domain transmit signal; and

a transmit antenna coupled to transmit the time domain transmit signal.

16. The transmitter of claim 15, further comprising:

a bit allocation block that allocates bits from the data stream as frequency coefficients.

17. The transmitter of claim 15, further comprising a channel estimation and matrix selection block that is coupled to a receiver to determine the estimated channel response and is further configured to determine the set of tone group preceding matrices from the estimated channel response.

18. A wireless communication method that comprises:

receiving a data stream;

allocating bits of the data stream to form frequency coefficients of orthogonal frequency division multiplexing (OFDM) tones that are partitioned into tone groups;

precoding the frequency coefficients to distribute them across their corresponding tone groups in accordance with tone group preceding matrices determined based on a channel response.

19. The method of claim 18, further comprising:

transforming precoded frequency coefficients into a time domain transmit signal; and

transmitting the time domain transmit signal.

20. The method of claim 19, further comprising:

receiving the tone group preceding matrices from a receiver of the time domain transmit signal.