Research On Ant-jamming Technology Of CDMA Communicate System

With the development of mobile communication, the number of mobile consumer increases rapidly, the contradiction between the growth of mobile communication portfolio and the limited frequency spectrum resources became more and more prominent. One way to solve above problem is to enhance the frequency spectrum using efficiency, then CDMA use different code sequence in each channel, and uses the orthogonal code sequence to make the channel orthogonal. However, it's very complicated for the signal's transmission because of the high building the complex circumstance and the movement of mobile consumer. The channel fading, expansion and the multi-path phenomenon cause inter-symbol interference and the same channel interference. It influences the signal transmission extremely serious. Therefore in CDMA system regarding anti-jamming technology research appears especially important.This article mainly focuses on in the CDMA system several kinds of anti-jamming system's research, such as the array signal processing theory, auto-adapted beam forming anti-jamming technology research. Researching predecessor's algorithm like MMSE, Steepest descent method, LMS and LCMV. proposing own viewpoint to improve system capability. The improved smooth algorithm based on the characteristic sub-space used deepen the null to fall the depth, enhanced the system's signal to noise ratio. Analyzing the algorithm that broadens the null when the unwanted signal position vibration very light, and confirming its feasibility. Studying the signal position vibration great time auto-adapted null track algorithm, it can make null aim jamming signal by tracking when null can not expended infinite. It can restrain the noise when it vibration very heavy.Next, Studying the space-time CDMA Multi-user Detection anti-jamming technology.