US 2002/0118731 A1 · RING MATCHED FILTER FOR SYNCHRONIZING TO A SPREADING CODE

Abstract

A mobile station is provided for receiving a spread spectrum, code division transmission from at least one transmitter, such as a base station. The mobile station contains a receiver for outputting data samples, and further contains a multi-tap ring matched filter. The ring matched filter is constructed to have first circuitry for storing an individual one of a received data sample into an individual one of a plurality storage registers such that a active data sample that has been stored for the longest period of time is overwritten with a most recently received data sample. The ring matched filter is further constructed to have second circuitry for serially shifting coefficient bits of at least one multi-bit spreading code relative to the storage registers for sequentially and simultaneously correlating the at least one multi-bit spreading code with a plurality of corresponding stored data samples, while significantly reducing power consumption by limiting state changes of flip-flops.

Claims20

Dependent claims

A matched filter, comprising:

an n-stage delay line for storing data samples;
an enable circuit having outputs for enabling the storage, in a sequential manner, of individual ones of said data samples into individual stages of said n-stage delay line;
an m-stage coefficient register for storing coefficient data, wherein adjacent stages of said coefficient register are serially coupled together for shifting coefficient data from stage to stage;
and
a plurality of combining circuits individual ones of which have inputs coupled to outputs of one of said delay stages and one of said coefficient register stages for combining said outputs together.

2 more elements

Dependencies are inferred from the claim text.

Ring matched filter for synchronizing to a spreading code

Life of this patent

Ring matched filter for synchronizing to a spreading code

Life of this patent

Abstract

Claims20