MODIFIED ANTISYMMETRIC M-SEQUENCE AND ITS PERIODIC CORRELATION PROPERTY

In this paper we discuss the binary spreading sequences whose spectral distributions are DC free and spectral distribution's shapes can be e asily controlled by a certain parameter denoted by delta. The newly de veloped sequences, referred to as modified antisymmetric M-sequences, are modified-versions of the conventional antisymmetric (AS) M-sequenc es. The proposed sequences are designed to increase the varieties of s pectral distribution's shapes and improve the correlation properties w hen compared to those of the FM coded M-sequences which have already p roposed by Tsuzuki et al. Some typical line coded M-sequences, i.e. th e (differential) Manchester coded M-sequences and the FM coded M-seque nces, and the conventional AS M-sequences are included in the set of p roposed sequences. The improvement of the average BER (bit error rate) performance for asynchronous DS/SSMA: (direct sequence/spread spectru m multiple access) systems using the proposed sequences in comparison to the system using the conventional AO/LSE (auto-optimal phase with l east sidelobe energy) M-sequences is also shown.