PLM-based channelization sequences for multi-code wideband DS-CDMA

A key problem in multi-code DS-CDMA communication systems is the limited resource in the code domain, i.e. limited number of available orthogonal channelization sequences. This problem causes the overall interference to be a limiting factor, especially when high symbol rate signaling is considered. In order to resolve this problem the literature has proposed many code management techniques, based essentially on code sharing mechanisms among the active users in the system. In this paper we propose a simpler method for the performance optimization of the multi-code DS-CDMA communication systems, based on the design of the channelization sequences used in the system. The optimal channelization sequences are implemented by means of chaotic piece wise linear Markov (PLM) sequences.