| 摘要 |
An apparatus for receiving a data stream consisting of a simultaneous plurality of time domain spread spectrum messages in the same frequency channel, wherein each message is independent and spread spectrally with a unique code. The data stream contains a subset of all known codes in use. The apparatus finds a specific code and a constant phase shift between the incoming code and a reference code by serially moving the data stream through a shift register, subjecting all the shift register outputs to a single expected reference code and accumulating the result for each output. The code and phase shift is indicated by the largest magnitude of the accumulation, above a set threshold, corresponding to the shift register output for the correct phase shift between the incoming code and the reference. Upon completion of an integration cycle the time shift delay increases by the length of the shift register. The process continues for all the possible relative time shifts and for all the reference codes.
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