Fast phase sequences spreading codes for CDMA using FFT

In multi-path environments, Spread Spectrum multiple access techniques offer attractive properties of rejection of undesired signals and an high spectral efficiency. In this paper is presented a design method for spreading codes which employs Perfect Sequences, a class of complex sequences with singular correlation properties. The main advantage from the use of Perfect Sequences is the oppportunity of a fast DSP implementation with FFT blocks, where the analog section is extremely contained. Simulations in a multipath enviroment confirm the useful caracteristics of the proposed receiver for asyncronous trasmissions.