CDMA COMMUNICATION METHOD USING MULTI-TYPE DIFFUSION SEQUENCE

摘要

A CDMA communications system using multiple spreading sequences is characterized in that, by providing means of that a sequence-set consisting of M kinds of basic spreading sequences, each sequence having code length L, is prepared, an information-set consisting of gamma components, not including the value 0 is made of a modulated sequence-set which are made by multiplying the said respective basic spreading sequences by an original information-set consisting of M components including (M - gamma ) pieces of the value 0, resulting in production of a selected sequence-set consisting of gamma selected spreading sequences, means of that a modulated synthesized sequence sD is produced by adding up all of the said selected spreading sequences, that a repeated core spreading sequence group sDN is produced of the said respective selected sequences, that an enveloped sequence eD is produced as an baseband transmit-data-frame by arranging the rear and the front parts of the said repeated core spreading sequence as the guard sequences, and that said data-frame modulates a carrier-wave having orthogonal frequency and then the resultant output is transmitted, and means of that a similar enveloped sequence ep is produced with a gilot-information p as a baseband transmit-pilot-frame, and that the said pilot-frame is transmitted so as not to interfere with similar data-frames and pilot-frames for other users.