Study On Multi-antenna Technology In The Downlink Of TD-SCDMA System

The development of mobile communication requires higher transmission rate and higher transmission quality recently. In order to satisfy asymmetry service of uplink and downlink data, the 3GPP introduces a new feature denominated High Speed Downlink Packet Access(HSDPA),which can increase the capacity of radio access network as well as support high data rates. Compared with the conventional SISO system, MIMO technique can greatly increase the capacity of the system with spatial diversity or spatial multiplex technology.We set up PARC MIMO and MIMO precoding in TD-SCDMA system,based on its characteristic. Computer simulation results demonstrate that using PARC MIMO technique can meet the requirement of Bit Error Ratio and SNR. The realization of TD-SCDMA+MIMO+HSDPA can greatly increase the capacity and reliability to a certain degree. It is difficult to accurately calculate the channel estimation, MIMO precoding set up a new Channel Impulse Response matrix, which is composed of Channel Impulse Response vector of the max power of every sub-channel. With the SVD decomposition of the new Channel Impulse Response matrix we can get precoding matrix and coding matrix. The method can greatly reduce the computing complication of UE, also increase system capacity and higher the rate of data transmitting. Computer simulation results demonstrate the reliability of the method.