The Key Technology Of SCDMA System From Fix To Mobile

SCDMA is a WLL (wireless local loop) system, which use the Smart antenna, Synchronous CDMA and Software Radio as the key technology. As a WLL system, SCDMA has the advantages in frequency and cost effective. In order to expand the markets, it is useful to change the SCDMA from WLL to mobile system. Some key technology about SCDMA from WLL to mobile is studied; the main research and achievement are given as follows:For TDD mode, the difference of wireless channel between fix and mobile is studied. Since the multi-path, it is impossible to realize the up link synchronous exactly, but the approximate synchronous can be realized.Consider the approximate synchronous, a new method is realized to increase the system up link quality. Some study results are given by computer simulation about the space-time processing in periodic and non-periodic spreading code system.The advantages of SCDMA at constructing network are given in theory. Some key parameters for constructing network are also given.The hand-over and roam methods, which are suitable for SCDMA, are studied and realized.Some new methods are given to overcome the problems in SCDMA system realization, such as non-synchronous acceding, interference. The smart antenna system architecture is also analyzed for wide band SCDMA system.