Sequence generation for asynchronous spread spectrum communication

摘要

A direct conversion receiver for delay-and-correlate transmitted reference spread spectrum signaling apparatus improves the performance of a delay-and-correlate transmitted reference spread spectrum communication system with essentially no added complexity over prior designs. The message signal contains the information to be communicated, which has been spread through multiplication (11) with a wide band spreading waveform from a sequence generator (12). The reference signal consists of the spreading waveform itself which the receiver can use to despread the message signal and recover the information. The spread waveform is delayed (13) and added (14) to the reference signal, and the summed signal is mixed (15) with a radio frequency signal for transmission (17). Operation of the invention hinges on generation of a class of reference signals at the transmitter which produce more reliable data output signals at the receiver.