Improvement And Comparison Of MIMO Space-Time Coding Technology On Unequal Antenna

The 3GPP(The 3rd Generation Partnership Project)has proposed and developed LTE(Long Term Evolution)in order to compete with Global Interoperability for Microwave Access(WiMAX).LTE has not been recognized by the ITU as a 4G label,which can be seen as a transition from 3G to4 G,commonly referred to as 3.9G.LTE and OFDM(Orthogonal Frequency Division Multiple Access)and MIMO(Multiple-Input Multiple-Output),the LTE network is mainly composed of base station(eNode B: Evolved Node B)and access(AGW: Access Gateway),eliminating the wireless network controller(RNC: Radio Network Controller)to achieve a flat network structure,reducing the delay caused by data transfer;canceled the circuit domain,to achieve a fixed network and Mobile network integration,flexible support for multimedia services,to achieve a network of all IP,the system capacity is improved,the user's transmission rate and system coverage is increased,the operating costs can be effectively reduced.The design goal of the LTE system is to achieve the peak of the uplink 50Mbps(the premise of 1 antenna transmission)and the downlink 100Mbps(the premise of 2 antenna reception)at 20 MHz system bandwidth.Compared with 3G,LTE uses its rapid response and high-speed transmission advantages,to meet the high-definition video online playback,fast file transfer,almost all wireless services for users,and to achieve this with its key technologies:orthogonal frequency division multiplexing(OFDM)and multiple input and output(MIMO)are closely related.This article focus on the D-BLAST coding method in space-time coding and improve it to ensure that the full-emission matrix occupancy rate achieved under the sacrifice of small delay,and the improved coding is applied to the mainstream coding technology in unequal antenna array,analyzes the antenna usage strategy,from the diversity gain,multiplexing gain,signal to noise ratio-bit error rate these three indicators to evaluate its performance.The results show that the improvement of D-BLAST is more significant than that in the specific case.Increasing the performance gain of the receiving antenna is often larger than that of the transmitting antenna.