Pseudorandom Sequence Generator for Spread Spectrum Communications

This paper presents the design and the practical implementation of an efficient pseudorandom sequence generator that is intended to be used in the development of multichannel, high speed, interference resistant spread spectrum communication systems. The versatility of the circuit is ensured by using a parallel architecture with multiple processing paths. In this mode, there are simultaneously obtained multiple pseudorandom sequences that can be periodically selected for efficiently spreading the data stream in a wireless communication link. The fundamental architectures used in the construction of the generator rely on the Linear Feedback Shift Register (LFSR) with various lengths and the Gold code. Although the implemented generator is based on a reduced number of flip-flops, which has the consequence of producing sequences with relatively small size, the performances regarding the statistical distribution of bits is close to a truly random stream. In addition, the used algorithms create pseudorandom sequences that are hardly predictable, which is a very useful property that makes the proposed circuit suitable for various application in digital communications but also in the field of data encryption.