Method and apparatus for partial interference cancellation in a communication system

• US 20020021747A1
• Filed: 06/06/2001
• Published: 02/21/2002
• Est. Priority Date: 07/10/2000
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Sequeira, Raul E.
• Granted Patent: US 7,315,567 B2
• Time in Patent Office: Days
• US Class Current: 375/148
• CPC Class Codes: H04B 1/7107 Subtractive interference cancellation
• CPC Class Codes: H04B 2001/71077 Partial interference cancellation

Abstract

A method of partial interference cancellation of a received signal including a first data component and a second data component includes the steps of

determining a characteristic of the communication channel, estimating a factor based upon the characteristic, using the factor to cancel the second data component from the signal, and recovering the first data component from the signal.

Claims

1. A method of interference cancellation comprising:

receiving a signal including at least a first data component and a second data component on a communication channel;

determining a characteristic of the communication channel;

estimating an interference factor based upon the characteristic;

using the interference factor to cancel the second data component from the signal; and

recovering the first data component from the signal.

2. The method of claim 1, wherein the interference factor comprises one of a data estimate and a partial interference coefficient.

3. The method of claim 1, wherein the signal comprises a spread spectrum code division multiple access system signal.

4. The method of claim 1, wherein the step of estimating comprises applying a function to the characteristic.

5. The method of claim 4, wherein the function comprises a piece-wise linear estimation of the hyperbolic tangent.

6. The method of claim 4, wherein the function comprises a piece-wise linear estimation of a probability error function.

7. The method of claim 1, wherein the characteristic comprises one of a signal estimation and a noise estimation.

8. In a receiver including interference cancellation, the receiver adapted to receive a signal including a first data component and a second data component, a method of providing a data estimate comprising the steps of:

estimating a signal-to-noise ratio for signal;

applying a function to the signal-to-noise ratio to determine a soft data estimate on a PCG-by-PCG for each of the first data component and the second data component; and

subtracting from the signal the soft data estimate of the second data component.

9. The method of claim 8, wherein the step of estimating a signal-to-noise ratio comprises estimating a first signal term and second signal term.

10. The method of claim 8, wherein the function comprises a piece-wise linear estimation of the hyperbolic tangent.

11. In a receiver including partial interference cancellation, the receiver adapted to receiver a signal including a first data component and a second data component, a method of providing a partial interference coefficient comprising the steps of:

estimating a first signal term and a second signal term of the signal;

applying a function to the signal-to-noise ratio to determine an intermediate parameter on a PCG-by-PCG basis;

using the intermediate parameter to determine a partial interference coefficient.

12. The method of claim 11, comprising the step of using the intermediate parameter to determine a second partial interference coefficient.

13. The method of claim 11, wherein the function comprises a piece-wise linear estimation of a probability error function.