Design of perfect complementary codes to implement interference-free CDMA systems

This paper introduces an algebraic approach to generate the super-set of perfect complementary (PC) codes suitable for interference-free CDMA applications. The code design methodology proposed here takes into account major impairing factors in real applications, such as MAI, multipath effect, asynchronous up link transmissions and random signs in consecutive symbols. Two important conclusions are drawn from the analysis in this paper. First, implementation of an interference-free CDMA will never be possible unless using some proper complementary code sets, such as the PC code sets proposed in this paper. Second, to enable interference-free CDMA operation, the block size of the PC codes must be made equal to their set size. The operational advantages of a CDMA system based on the PC codes is also discussed and its performance is compared with traditional CDMA systems by simulations, showing that the PC code based CDMA architecture offers a performance limited only by noise.