Recent spreading codes for spread spectrum communication systems
Shin’ichi Tachikawa · Electronics and Communications in Japan (Part I Communications) · 1992
Abstract This paper presents recent spreading codes and their applications to spread spectrum (SS) systems. First, co‐channel interference in spread spectrum multiple access communication systems (SSMA) and cross‐correlation functions are described, and the relationship between new “No sequences” with low cross‐correlations and other well known sequences is summarized. Second, an SSMA using very low‐rate convolutional codes proposed by Viterbi is described. With this SSMA the spectral efficiency can be improved over that of FDMA using a guardband. Finally, optical orthogonal codes for fiber networks, orthogonal Gold sequences, orthogonal Bent sequences for synchronous SSMA, majority logic combination sequences using M‐sequences, and generalized Geffe sequences for rapid acquisition are described.