Research On Noncoherent Detection For Cooperative Systems With Distributed Space-time Coding

Multiple Input and Multiple Output (MIMO) is a key technology of wirelesscommunication, which greatly improve spectrum efficiency and channel capacitywithout increasing the bandwidth. As an extension approach of MIMO, cooperativecommunication has attracted more and more attention due to its ability to combine theadvantage of diversity technology and relay transmission technology.Since the dispersion characteristics of the cooperative systems，channel stateinformation (CSI) estimation not only increases the complexity of the system but alsoreduces the efficiency of the transmission of information, thus it is necessary to studynoncoherent detection without channel information. In this thesis, firstly, differentnoncoherent detection scheme are analyzed for corresponding cooperative systems,and a noncoherent receiver based on semidefinite relaxation (SDR) approach isproposed for cooperative systems with distributed orthogonal space-time code.Furthermore, a new signaling method that combines channel estimation and detectionat relays is considered. In comparison with the coherent detection, the proposedalgorithm does not require any channel state information at destination. At theexpense of acceptable performance loss, the new signaling method further reduces therequests for the channel information from source to relay. Finally, a noncoherentdetection scheme is proposed for cooperative systems with multi-antenna relays. Therelay node with maximum ratio combining (MRC) techniques makes full use ofmulti-antenna diversity gain, and the performance of noncoherent detection isimproved effectively.