2008/10/01 by Koichiro Kitagawa, Toshiyuki Tanaka, Kitagawa, Koichiro +1
Computer Science · Engineering · #Advanced Wireless Communication Techniques #FOS: Computer and information sciences #Information Theory (cs.IT) #Wireless Communication Networks Research #graph theory and CDMA systems
paper · pdf · doi:10.48550/arxiv.0810.0154
openalex publication_date 2008/10/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Statistical mechanics approach is useful not only in analyzing macroscopic system performance of wireless communication systems, but also in discussing design problems of wireless communication systems. In this paper, we discuss a design problem of spreading sequences in code-division multiple-access (CDMA) systems, as an example demonstrating the usefulness of statistical mechanics approach. We analyze, via replica method, the average mutual information between inputs and outputs of a randomly-spread CDMA channel, and discuss the optimization problem with the average mutual information as a measure of optimization. It has been shown that the average mutual information is maximized by orthogonally-invariant random Welch bound equality (WBE) spreading sequences.