US 6,683,924 B1 · Apparatus and methods for selective correlation timing in rake receivers

Abstract

Correlation times for a RAKE receiver are determined from time differentials between multipath components of a received signal based on correlation metrics, preferably signal strength measurements, associated with the multipath components. According to various embodiments of the present invention, selection strategies are employed in which “desired signal collecting” and “interference collecting” correlation times may be selected using average optimal (AO) or instantaneous optimal (IO) selection criteria. These criteria may include, for example, thresholds for signal strengths associated with multipath components of a signal at the correlation times, where the signal strengths may include absolute or relative measures of signal power or signal to noise ratio. According to alternative embodiments, correlation times are selected using an inverse filter of an estimated channel response. Related apparatus is also described.

Claims58

Dependent claims

A method of processing a communications signal, the method comprising the steps of:

generating respective correlation metrics for respective ones of a plurality of multipath components of a first signal, a respective one of which has a respective time associated therewith;
and
generating respective time-offset correlations of a second signal with a modulation sequence at respective correlation times determined from time differentials between the times associated with the plurality of multipath components based on the correlation metrics associated with the plurality of multipath components.

A receiver, comprising:

a correlation timing determiner, responsive to a first signal, that generates respective correlation metrics for respective ones of a plurality of multipath components of the first signal, a respective one of which has a respective time associated therewith, and determines a set of correlation times from time differentials between the times associated with the plurality of multipath components based on the correlation metrics associated with the plurality of multipath components;
a correlation unit operatively associated with the correlation timing determiner and responsive to a second signal, that generates respective time-offset correlations of a second signal with a modulation sequence at respective correlation times of the selected set of correlation times;
and
a combiner that combines the time-offset correlations of the second signal with the modulation sequence to produce an estimate of information represented by the second signal.

1 more element

A receiver, comprising:

means for generating respective correlation metrics for respective ones of a plurality of multipath components of a first signal;
and
means, responsive to said means for generating respective correlation metrics, for generating respective time-offset correlations of a second signal with a modulation sequence at respective correlation times determined from time differentials between times associated with the plurality of multipath components based on the correlation metrics associated with the plurality of multipath components.

Dependencies are inferred from the claim text.

Apparatus and methods for selective correlation timing in rake receivers

Life of this patent

Apparatus and methods for selective correlation timing in rake receivers

Life of this patent

Abstract

Claims58