Wireless precoding methods

• US 8,693,575 B2
• Filed: 09/20/2011
• Issued: 04/08/2014
• Est. Priority Date: 08/09/2004
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Dabak, Anand G., Onggosanusi, Eko N.
• Primary Examiner(s): LAM, KENNETH T
• Application Number:
  US13/237,543
• Publication Number:
  US 20120008718A1
• Time in Patent Office: 931 Days
• Field of Search: 375/295, 375/298, 375/259, 375/260, 375/261
• US Class Current: 375/298
• 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 precoding block, a transform block, and multiple transmit antennas. The antenna precoding 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 precoding may be employed in a single channel system.

Claims

1. A wireless transmitter comprising:

plural input serial data bit streams;

bit allocation blocks having inputs coupled to the input serial data streams and having outputs, the bit allocation blocks apportioning data bits among available tones and each bit allocation block outputting a quadrature amplitude modulation (QAM) constellation signal point for each tone;

tone group precoding matrix blocks having inputs coupled to the outputs of the bit allocation blocks and having outputs, the tone group precoding matrix blocks distributing signal energy across the tone groups for each of the multiple data streams to distribute the data bits across multiple tones and maximize the communications bandwidth of the system;

antenna precoding matrix blocks having inputs coupled to the outputs of the tone group precoding matrix blocks and having outputs, the antenna precoding matrix blocks being applied to the tones to distribute the energy of the tones across the outputs of the antenna precoding matrix blocks to distribute the data bits across multiple antennas and maximize the communications bandwidth of the system; and

inverse fast Fourier Transform and parallel to serial blocks having inputs coupled to the outputs of the antenna precoding matrix blocks.

2. The wireless transmitter of claim 1 in which there is a separate antenna precoding matrix block for each tone.

3. The wireless transmitter of claim 1 in which there is one antenna precoding matrix block for a group of tones.

4. The wireless transmitter of claim 1 in which 256 available tones are divided into 32 groups of 8 tones each and there are 32 antenna precoding matrix blocks, one for each group.

5. The wireless transmitter of claim 1 in which the tone group precoding matrix blocks distribute signal energy equally across the tone groups for each of the multiple data streams.

6. The wireless transmitter of claim 1 in which the antenna precoding matrix blocks are applied to the tones to distribute the energy of the tones equally across the outputs of the antenna precoding matrix blocks.

7. The wireless transmitter of claim 1 in which the bit allocation blocks, the tone group precoding matrix blocks, and antenna precoding matrix blocks are free of feedback from a receiver.

8. A wireless transmitter comprising:

plural input serial data bit streams;

bit allocation blocks having inputs coupled to the input serial data streams and having outputs, the bit allocation blocks apportioning data bits among available tones and each bit allocation block outputting a quadrature amplitude modulation (QAM) constellation signal point for each tone;

tone group precoding matrix blocks having inputs coupled to the outputs of the bit allocation blocks and having outputs, the tone group precoding matrix blocks distributing signal energy across the tone groups for each of the multiple data streams to distribute the data bits across multiple tones and maximize the communications bandwidth of the system;

an antenna precoding matrix block having inputs coupled with the outputs of the tone group precoding matrix blocks and having outputs, the antenna precoding matrix block being applied to the tones to distribute the energy of the tones across the antenna precoding matrix block outputs to distribute the data bits across multiple antennas and maximize the communications bandwidth of the system;

inverse fast Fourier Transform and parallel to serial blocks having inputs coupled to the outputs of the antenna precoding matrix blocks.

9. The wireless transmitter of claim 8 in which the tone group precoding matrix blocks distribute signal energy equally across the tone groups for each of the multiple data streams.

10. The wireless transmitter of claim 8 in which the antenna precoding matrix block is applied to the tones to distribute the energy of the tones equally across the outputs of the antenna precoding matrix block.

11. The wireless transmitter of claim 8 in which the bit allocation blocks, the tone group precoding matrix blocks, and antenna precoding matrix block are free of feedback from a receiver.