Quasi‐synchronous code division multiple access (CDMA) with binary shift‐register sequences
S. Kuno, Takaya Yamazato, Masaaki Katayama, Akira Ogawa · Electronics and Communications in Japan (Part III Fundamental Electronic Science) · 1996
Abstract This paper discusses the quasi‐synchronous code‐division multiple access system (QS‐CDMA), where the time error in the synchronized access is allowed for a certain range, based on the spread‐spectrum communication technique. the Gold sequence and the M sequence, which are the binary shift‐register sequences, are used to derive the set of quasi‐synchronous spread sequences (QS‐sequence) considering the auto‐ and cross‐correlation characteristics, realizing a wide tolerable range for the timing error. The QS‐CDMA system using such QS‐sequence is investigated, and the effectiveness is examined. As a result, it is seen that the performance is improved greatly by using the QS‐sequence presented in this paper, compared to the asynchronous CDMA system. It is shown also that the tolerable range for the access timing error is enlarged compared to the synchronous CDMA system.