Method and apparatus for partial interference cancellation in a communication system

• US 7,315,567 B2
• Filed: 06/06/2001
• Issued: 01/01/2008
• Est. Priority Date: 07/10/2000
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Sequeira, Raul E
• Primary Examiner(s): ODOM, CURTIS B
• Application Number:
  US09/875,474
• Publication Number:
  US 20020021747A1
• Time in Patent Office: 2,400 Days
• Field of Search: 375/148, 375229-236, 714/795
• 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 that includes a first data component and a second data component is disclosed. The method 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 in a multiple access communication channel comprising:

receiving a signal including at least a first data component for a first channel within the multiple access communication channel and a second data component for a second channel within the multiple access communication channel on the communication channel;

determining a characteristic of one stage of the multiple access communication channel;

estimating an interference factor caused by the second data component received on the multiple access communication channel based upon an approximation of the characteristic and comprises applying a function to the characteristic and wherein the function comprises a piece-wise linear estimation of a hyperbolic tangent;

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

recovering the first data component from the signal.

2. A method of interference cancellation in a multiple access communication channel comprising:

receiving a signal including at least a first data component for a first channel within the multiple access communication channel and a second data component for a second channel within the multiple access communication channel on the communication channel;

determining a characteristic of one stage of the multiple access communication channel;

estimating an interference factor caused by the second data component received on the multiple access communication channel based upon an approximation of the characteristic and comprises applying a function to the characteristic and wherein the function comprises a piece-wise linear estimation of a probability of error function;

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

recovering the first data component from the signal.

3. In a receiver including interference cancellation in a multiple access communication channel, the receiver adapted to receive a signal for the communication channel including a first data component for a first channel within the multiple access communication channel and a second data component for a second channel within the multiple access communication channel, a method of providing a data estimate comprising the steps of:

estimating a signal-to-noise ratio for the signal;

applying a function to the signal-to-noise ratio to determine an approximation of a soft data estimate caused by the second data component received on the multiple access communication channel on a power control group by power control group basis for each of the first data component and the second data component;

wherein the function comprises a piece-wise linear estimation of the hyperbolic tangent

subtracting from the aggregate received signal the signal estimate involving soft data estimate of the second data component.

4. In a receiver including partial interference cancellation in a multiple access communication channel, the receiver adapted to receive a signal for the communication signal including a first data component for a first channel within the multiple access communication channel and a second data component for a second channel within the multiple access communication channel, a method of providing a partial interference cancellation coefficient comprising the steps of:

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

applying a function to a signal-to-noise ratio to determine an approximation of an intermediate parameter caused by the second data component received on the communication channel on a power control group by power control group basis wherein the function comprises a piece-wise linear estimation of a probability of error function, and

using the intermediate parameter to determine a partial interference cancellation coefficient.