High speed generation of pseudonoise sequences

摘要

This paper proposes a type of interpolated Bitfilter for producing high speed pseudonoise (PN) sequences. The interpolated Bitfilter consists of two parallel polyphase Bitfilters, two expanders and one delay element. Through the expanders and delay element, the m-sequences produced by the two parallel polyphase Bitfilters are time-interleaved, thus the PN-sequences generated by the interpolated Bitfilter are obtained. The design example is given, and its result has revealed that the interpolated Bitfilter is able to generate higher speed PN-sequences whose period length is identical with that of the m-sequences generated by parallel polyphase Bitfilters. Due to the concurrent computations of implementation structure, this class of Bitfilter which produces faster PN-sequences can be realized easily using relatively lower cost circuit. It is obvious that this type of Bitfilter is efficient and helpful in generating PN-sequences.