CDMA Receiver using sampled chip sequence for precision synchronization with received data sequence

摘要

A CDMA communication receiver comprises a memory (24) for storing chip samples representing amplitudes of a despreading chip sequence sampled at intervals smaller than chip intervals of the chip sequence. From the memory, sync search and tracking circuitry (26) reads a set of chip samples spaced from each other by the chip intervals and spaced from corresponding chip samples of adjacent sets by the smaller intervals, and detects a match or mismatch between the read chip samples and the incoming data sequence. If they match, it is determined that the read chip samples is a synchronized chip sequence. Otherwise, a next set of chip samples is read from the memory for making a further test between the next set and the incoming data sequence. A despreading filter (27) despreads the incoming data sequence with the synchronized chip sequence.