Principle And Practice Research Of The Joint Receiver

At present, TD-SCDMA, of which china has Independent intellectual property rights, has been faced both opportunities and challenges. On the one hand, our government and some domestic institutes have been trying their best to support TD-SCDMA over past years, but on the other hand, some data from the application results was not optimistic, especially, WiMax, which became one of the 3G standards, has a great impact on TD-SCDMA.Joint Detection is one of the key technologies in TD-SCDMA, there are some difficulties and problems that should be concerned when realizing it in actual projects. Smart Antenna is core technology and must be selected, so while doing research on Joint Detection, it is necessary to combine JD with SA to analyse the structure of receiver.First, the paper compares the main standards of 3G and briefly introduces the frame structure and the key technologies of TD-SCDMA system. Then it introduces the principle of smart antenna and its application in TD-SCDMA, and analyses the principle of joint detection according to TD-SCDMA system model, and summarizes some characteristics of it. In some situation, joint detection can eliminate multiple path interference and multiple access interference absolutely. But the ability of eliminating the additive noise in the system is limited, and it has a great dependence on channel estimation.After referring to a lot of articles, finally, the principle and model of eliminating MPI making use of the local despreading code and midamble of TD-SCDMA standard is giving in the paper. At the same time, the TD Joint Receiver by the above model possible to be used are presented in the paper,and the algorithm of the joint detection has been improved.