Method and apparatus for selectively applying interference cancellation in spread spectrum systems

Patent metadata

Field	Value
Publication number	US-9319152-B2
Application number	US-201414502479-A
Country	US
Kind code	B2
Filing date	Sep 30, 2014
Priority date	Sep 23, 2002
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

The present invention is directed to the selective provision of interference canceled signal streams to demodulating fingers in a communication receiver. According to the present invention, potential interferer signal paths are identified. Signal streams having one or more potential interferer signals removed or canceled are created, and a correlation is performed to determine whether the strength of a desired signal path increased as a result. If the correlation indicates that the strength of a desired signal path was increased by the signal cancellation, the interference canceled signal stream is provided to the demodulation finger assigned to track the desired signal path. If the correlation determines that the strength of the desired signal path did not increase as a result of performing interference cancellation, the raw or a different interference canceled signal stream is provided to the demodulation finger.

First claim

The invention claimed is:

1. An apparatus comprising:
a plurality of demodulation fingers, wherein each of the plurality of demodulation fingers includes an input; and
a cancellation controller configured to selectively provide:
in a first mode, an interference-cancelled signal stream to the inputs of the plurality of demodulation fingers; and
in a second mode, a non-interference-cancelled signal stream to the inputs of the plurality of demodulation fingers.

2. The apparatus of claim 1 , further comprising:
a searcher finger, wherein the cancellation controller is configured to selectively provide one of the interference-cancelled signal stream or the non-interference-cancelled signal stream to the searcher finger.

3. The apparatus of claim 1 , wherein the cancellation controller comprises:
a channel determination module configured to provide at least one replica of an interfering signal path; and
a signal cancellation module operable to remove the at least one replica of the interfering signal path from another signal stream.

4. The apparatus of claim 3 , wherein the cancellation controller further comprises:
a plurality of channel determination modules, each of which is configured to provide the replica of the interfering signal path; and
a plurality of signal cancellation modules, each of which is configured to remove the at least one replica of the interfering signal path from another signal stream.

5. The apparatus of claim 4 , wherein the number of demodulation fingers is greater than the number of channel determination modules.

6. The apparatus of claim 4 , wherein the number of demodulation fingers, the number of channel determination modules, and the number of signal cancellation modules are equal.

7. The apparatus of claim 1 , wherein each of the plurality of demodulation fingers comprises a tracking module and a demodulation module.

Assignees

• Iii Holdings 1 Llc

Inventors

• Narayan Anand P
• Olson Eric S
• Jain Prashant

Classifications

• H04B15/00 Primary

  Suppression or limitation of noise or interference (by means associated with receiver H04B1/10) · CPC title

• H04B1/7107 Primary

  Subtractive interference cancellation · CPC title

• H04J13/00

  Code division multiplex systems (for frequency hopping H04B1/713) · CPC title

• H04W24/08

  Testing, {supervising or monitoring} using real traffic · CPC title

• H04B1/7117

  Selection, re-selection, allocation or re-allocation of paths to fingers, e.g. timing offset control of allocated fingers · CPC title