Multi-channel frequency domain equalizer for radio frequency interference cancellation

• US 6,999,508 B1
• Filed: 11/07/2000
• Issued: 02/14/2006
• Est. Priority Date: 11/07/2000
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Redfern, Arthur J.
• Primary Examiner(s): Fan, Chieh M.
• Assistant Examiner(s): Perilla, Jason M.
• Application Number:
  US09/707,874
• Time in Patent Office: 1,925 Days
• Field of Search: 375/222, 375/229, 375/230, 375/232, 375/316, 375/346, 375/350, 375/147
• US Class Current: 375/229
• CPC Class Codes: H04L 2025/03414 Multicarrier
• CPC Class Codes: H04L 2025/03522 Frequency domain
• CPC Class Codes: H04L 25/03159 operating in the frequency domain H04L25/03165, H04L25/03178 take precedence

Abstract

A multichannel frequency domain equalizer improves the subchannel signal to noise ratio by canceling correlated noise that is caused by deterministic spreading at the receiver that introduces correlation into the subchannel noise vector.

Claims

1. A method of canceling communication system noise interference, the method comprising the steps of:

(a) receiving T blocks of data, Y(;

, t), t=1, . . . , T, comprising T blocks of data, X(;

,t), t=1, . . . , T, transmitted over predetermined subchannels;

(b) determining a set of the predetermined subchannels, k(n), to generate coefficients for a multichannel frequency domain equalizer (FEQ) of a subchannel n of the predetermined subchannels;

(c) generating multichannel FEQ coefficients, g(n), for the subchannel n of the predetermined subchannels used to transmit the received T blocks of data; and

(d) performing multichannel frequency domain equalization for the subchannel n using the generated multichannel FEQ coefficients;

wherein the step of determining the set of the predetermined subchannels, k(n), for the subchannel n includes selecting subchannel n;

wherein the step of determining the set of the predetermined subchannels, k(n), for the subchannel n further includes selecting neighboring subchannels to the subchannel n.

2. The method of canceling communication system noise interference according to claim 1 wherein steps (b)–

(d) are repeated for each subchannel n of the predetermined subchannels used to transmit the received T blocks of data.

3. A method of canceling communication system noise interference, the method comprising the steps of:

(a) receiving T blocks of data, Y(;

, t), t=1, . . . , T, comprising T blocks of data, X(;

,t), t=1, . . . , T, transmitted over predetermined subchannels;

(b) determining a set of the predetermined subchannels, k(n), to generate coefficients for a multichannel frequency domain equalizer (FEQ) of a subchannel n of the predetermined subchannels;

(c) generating multichannel FEQ coefficients, g(n), for the subchannel n of the predetermined subchannels used to transmit the received T blocks of data; and

(d) performing multichannel frequency domain equalization for the subchannel n using the generated multichannel FEQ coefficients;

wherein the step of determining the set of the predetermined subchannels, k(n), for the subchannel n includes selecting subchannel n;

wherein the step of determining the set of the predetermined subchannels, k(n), for the subchannel n further includes selecting subchannels where radio frequency interference is located.

4. A method of canceling communication system noise interference, the method comprising the steps of:

(a) receiving T blocks of data, Y(;

, t), t=1, . . . , T, comprising T blocks of data, X(;

,t), t=1, . . . , T, transmitted over predetermined subchannels;

(b) determining a set of the predetermined subchannels, k(n), to generate coefficients for a multichannel frequency domain equalizer (FEQ) of subchannel n of the predetermined subchannels;

(c) generating multichannel FEQ coefficients, g(n), for the subchannel n of the predetermined subchannels used to transmit the received T blocks of data; and

(d) performing multichannel frequency domain equalization for the subchannel n using the generated multichannel FEQ coefficients;

wherein the step of determining the set of the predetermined subchannels, k(n), for the subchannel n includes selecting subchannel n;

wherein the step of determining the set of the Predetermined subchannels, k(n), for the subchannel n further includes selecting subchannels having predetermined noise characteristics.

5. A method of canceling communication system noise interference, the method comprising the steps of:

(a) receiving T blocks of data, Y(;

, t), t=1, . . . , T, comprising T blocks of data, X(;

,t), t=1, . . . , T, transmitted over predetermined subchannels;

(b) determining a set of the predetermined subchannels, k(n), to generate coefficient for a multichannel frequency domain equalizer (FEQ) of subchannel n of the predetermined subchannels;

(c) generating multichannel FEQ coefficients, g(n), for the subchannel n of the predetermined subchannels used to transmit the received T blocks of data; and

(d) performing multichannel frequency domain equalization for the subchannel n using the generated multichannel FEQ coefficients;

wherein the step of generating multichannel FEQ coefficients, g(n), for the subchannel n, comprises solving the equation g(n)=Y(n)<sup>−

1</sup>x(n), where Y(n)<sup>−

1</sup> is the pseudoinverse of a matrix of received data for subchannels k(n), and x(n) is a vector of transmitted data for the subchannel n.