Key Technology Research For Full-duplex Communicaiton System

The rapid development of information technology has profoundly sh aped the way people live.With the growing demands for communication capacity and quality,higher requirements are put forward for future mobile communication system.Meanwhile,the shortage of spectrum resources has become a major problem to be solved in wireless communications.Currently,new technologies of communication aiming to improve spectrum efficiency are being researched,full-duplex technology is one of them.Full-duplex can simultaneously transmit and receive information on the same frequency band.But the system capacity cannot get the desired promotion due to the self-interference.With the development of self-interference cancellation technology,full-duplex technology will be more widely applied.In this paper,the technologies of resource scheduling for full-duplex cellular system and antenna selection for full-duplex bidirectional MIMO communication system are studied,the main achievements are as follows:(1)The resource scheduling algorithms for full-duplex cellular systems are proposed.At first,two scheduling algorithms based on MAX C/I are discussed,one is sequential scheduling algorithm,and the other one is joint scheduling algorithm.These two algorithms have better system capacity then the independent scheduling algorithm.The joint algorithm presents obvious advantages in downlink system capacity compared with the sequential algorithm,while sequential scheduling algorithm has lower computational complexity.In additional,the scheduling algorithms based on PF are proposed,which includes the optimal joint resource scheduling algorithm and two sub-optimal algorithms,namely the space isolation algorithm and the user filtering and dynamic adjusting algorithm.The optimal algorithm acquires the optimal user pair through traversing all the pairs,the channel information between uplink and downlink users is required at the base station,which causes large overhead.The two sub-optimal algorithms can acquire good throughput with no need for the channel information between users.(2)The transmit antenna selection algorithms for full-duplex bidirectional MIMO(Multiple Input Multiple Output)system are proposed.The exhaustive search algorithm can obtain the optimal performance through traversing all the possible antenna subsets,while its computational complexity grows exponentially with respect to the antenna scale.When the antenna scale is large,the complexity is too high.Two complexity reduction algorithms are analyzed in this paper,they are antenna removing algorithm based on greedy approach and antenna selection algorithm based on iteration convex optimization.These two algorithms can approach the exhaustive search with lower computational complexity.The simulation results show that,when transmit power or residential self-interference varies in a certain range,the two sub-optimal algorithms still approach the optimal algorithm.