METHOD AND APPARATUS FOR DESPREADING SPREAD SPECTRUM SIGNALS

摘要

A system for despreading and/or demodulating spread spectrum codes is provided. A receiver (601) comprises a plurality of delay elements (603) or a shift register with a plurality of taps configured to recognize one or more of the predetermined symbol codes. Delayed representations of the received signal are generated and combined (605) to produce a known output sequence, such as a string of consecutive one or consecutive zeros, when a recognizable spread spectrum code is received. The receiver shift register (610) may be preloaded such that recognition may occur starting with the first received chip. More than one set of taps may be coupled to the same shift register (610), so that more than one of the M spreading codes may be recognized by the same shift register (610). More than one symbol may be simultaneously transmitted using quadrature phase modulation or like techniques, and recognized by the receiver.