The Research Of High Spectral Efficiency Full-duplex Communication Technology

In recent years, research and development of the fifth generation of mobile communications,which meet the needs of high spectral efficiency,is evolving,In-Band Full Duplex(IBFD) communication theory and technology is also becoming a hot topic.If the self-interference problem is effectively solved, IBFD technology can not only improve the spectrum efficiency, but also can improve the delay characteristics of the medium access layer. For Multiple Input Multiple Output(MIMO) configuration, this thesis mainly studies multi-user cellular system’s sum rate performance and bidirectional IBFD interference mitigation scheme.The main work includes:(1) It describes the background and significance of the full duplex communication technology, and summarizes the development track of the current full duplex technology, then elaborates the key technology of full duplex communication and summarizes the full-duplex technology for various applications in a wireless communication network.Finally, the 5G mobile wireless network model based on full duplex technology is proposed.(2) It studies IBFD multi-user MIMO cellular system. In theory, the In-band full duplex wireless transmission technology has the potential to double the spectrum efficiency of the wireless cellular system, but the residual self interference in the base station receiver may seriously affect the performance of the uplink receiver. In order to improve the sum rate performance of the multi user system, we propose a simple method for downlink user selection(that is calculate the norm of the downlink channel), which can reduce the impact of residual self interference.(3) It studies a method of using QR-EVD(QR decomposition and eigenvalue decomposition) to obtain the multi-user MIMO system’s downlink precoding matrix. Compared with the traditional SVD-BD(Singular value decomposition and block diagonalization) scheme and the QR-EVD scheme, although both have similar sum rate performance, but the former has less computational complexity.(4) It studies a bidirectional full-duplex MIMO link rate progressive expression, and complete the relevant numerical simulation. Simulation results show: Under the condition of a small number of antennas, the time-domain self-Interference elimination scheme has a better performance than the spatial-domain self-Interference suppression scheme.