Hybrid Beamforming in Full-Duplex MIMO Wireless Systems

• Main Authors: Feng-Cheng Wei, 魏逢成
• Other Authors: Char-Dir Chung
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/8xq627

碩士 === 國立臺灣大學 === 電信工程學研究所 === 105 === Full-duplex (FD) wireless communication is one of the fifth generation of mobile communication techniques since it can double the spectral efficiency of the conventional half-duplex (HD) communication system. However, the spectral efficiency will be limited by the presence of self-interference and co-channel interference. In millimeter wave (mmWave) band, signals experience severe path loss in contrast to the conventional microwave band. Due to the shorter wave length, a large number of antennas can be packed tightly. Our goal is to maximize the sum rate of the millimeter wave full-duplex MIMO cellular system. Because of the power consumption for each RF chain, the cost is extremely high to perform digital beamforming when the number of antenna is large. From above reason, we choose hybrid beamforming structure which combines digital beamforming and analog beamforming to reduce the number of RF chains at the base station. Due to the multiplication of beamforming matrix, the objective function is non-convex which is difficult to obtain the global optimal solution. In this thesis, two novel hybrid beamforming algorithm to solve the non-convex optimization problem are proposed. By adding the semi-unitary constraint to the digital transmit beamforming, we develop a non-iterative solution which is called semi-unitary hybrid beamforming (SUHB). Moreover, we design another algorithm which is called downlink power control hybrid beamforming (DPCB) to find beamforming pairs while the quality of uplink achievable rate is maintained.