The .m file simulates a Spread-Spectrum Modulation Trx/Rcx system, in which, the phase of the pseudo-random sequence generated in the transmitter and used to encode the data stream is unknown a priory at the receiver.A parallel search strategy is employed to locally determine it in the place. It works as here: selecting the maximam-energy low-pass filtered signal of the set of all hypothesied despreaded ones using different hypothesized phases for the PN-sequence.The simulation can be growed in several ways including considering various types of noise and jammings or also designing better filters.