Interference Control Research For Full-duplex Wireless Communication System

With the rapid development of mobile intelligent equipments and mobile Internet applications,the mobile data services growth rapidly which poses a great challenge to the wireless communication system with scarce spectrum resources.Full-duplex(FD)communication,which allows simultaneous reception and transmission at the same frequency,can theoretically double the spectral efficiency of the system.With the rapid development of self-interference cancellation(SIC)technology,FD technology has the opportunity to apply in the 5G mobile wireless communication system.However,it can increase the number of the co-frequency interference links,which use the same spectrum resources simultaneously.The co-frequency interference environment becomes very complex.Thus,it is very important to analyze the interference control technology of the FD wireless communication system.In this thesis,we mainly focus on the following two interference control technologies:The power allocation-based interference control scheme is proposed.The residual self-interference(RSI)and the co-channel interference are firstly analyzed,where the FD cellular communication and the half-duplex(HD)Device-to-Device(D2D)communication are permitted to share the same spectrum resources.Considering the RSI of the FD equipment is reduced to the noise level,a power allocation algorithm is proposed to mitigate the interference between FD cellular communications and D2D communication.First,under the condition of meeting the requirement of FD cellular communication rate,a transmit power-based optimization problem is formulated to optimize D2D communication rate.Through allocating the power at cellular uplink user,base station and D2D transmitter,the results show that the max rate gain of D2D communication is about 65%and does not attenuate the rate of cellular transmission.The interference limited area-based interference control scheme is proposed.The RSI and co-channel interference for each node are first analyzed,where FD D2D communication is permitted to share the same spectrum with multi-HD cellular communications.In order to control the interference caused by multiple uplink cellular users to FD D2D users,an interference control scheme is proposed by setting the interference limited area for the D2D users.In the scheme,an interference limited area can be obtained through the interference to signal ratio threshold.Then,with the proposed interference control scheme,the ergodic capacity offered by FD D2D communication is derived.When the RSI is small,the results show that the FD D2D with the proposed scheme can provide a nearly double ergodic capacity gain.In conclusion,the proposed interference control technology can effectively alleviate the co-channel interference in the FD system.The performance of the entire communication system can be effectively improved,while guaranteeing the performance of cellular communication.Thus,the proposed interference control algorithms are meaningful for the effective realization of FD technology in the wireless communication system.