Research On Joint Transmission Technology In Cooperative Communication

With the rapid development of wireless communications, the research of Cooperative Communication technology arouses more and more people's attention. This technology is different from the traditional space diversity technology and the wireless relay technology, but is that one terminal resorts other terminal's help to complete the communication.P.W.Baier and other researchers proposed a novel multi-user transmission scheme, which is an alternative rationale for the downlink of TD-SCDMA termed joint transmission (JT). This paper researches low complexity detection scheme based on JT in multi-user MIMO downlink (denoted as JT MIMO scheme in this paper). We can conclude that the system performance and capacity can be significantly improved by JT MIMO scheme. And JT MIMO can greatly reduce receiver's calculative cost for multi-user MIMO downlink.This paper researches the application of Cooperative Communication in TD-SCDMA downlink. With some design principles we give a simple Cooperative Communication scheme for downlink of TD-SCDMA system. Because of using in CDMA networks the Cooperative Communication is different than in ad-hoc or other wireless networks and it can get symbol-level timing synchronization or orthogonal channelization between the base station and relay or relay and destination mobiles directly. For the problem that the relay and destination mobiles how to get precise channel impulse response (CIR), we use joint transmission (JT) technology to solve it. In the process, a receiver is also designed with algorithms――DMF,ZF-BLE and MMSE-BLE. Then through simulation and analysis we demonstrate the scheme is superiority and application prosperity.