Key Techniques For Digital Domain Suppression Of Mutual Coupling Interference In Dual-Channel Transceiver

The utilization of diversity gain with multiple antenna technology has improved the efficiency of wireless communication information transmission.However,due to nonideal characteristics of physical devices,there is mutual coupling interference between antenna channels during signal transmission,which deteriorates the quality of received signals.For example,for a dual-polarized antenna with a frequency of 2.4GHz and a relative bandwidth of 26.7%,the isolation is only about –32d B.In addition,considering the nonlinear distortion effects caused by nonlinear devices such as power amplifiers in the system,the coupling interference situation in the system is even more complex.This thesis focuses on dual-channel systems and designs digital domain suppression techniques for linear and nonlinear coupling interference under engineering constraints such as frequency offset,sampling rate deviation,phase noise,and system bandwidth.The main content includes:First,the thesis analyzes the types of mutual coupling interference and their impact on multi-channel systems.It starts by examining the mechanism of mutual coupling interference generation and action,considering the influence of nonlinear devices.The effects of both linear and nonlinear coupling interference on multi-channel systems are analyzed,and the study delves into commonly used power amplifier linearization methods and receiver coupling interference suppression algorithms.Next,the thesis presents a linear coupling interference suppression algorithm for dual channel systems.The components of linear coupling interference are analyzed and derived from the formula,followed by the introduction of a dual channel linear coupling interference model.Under engineering constraints such as frequency offset,sampling rate offset,and phase noise,a receiver linearly coupled interference suppression algorithm is proposed,along with corresponding solutions for non-ideal factors like frequency offset,sampling rate offset,and phase noise.Simulation results demonstrate that after interference suppression,the EVM(Error Vector Magnitude)of the dual channel 1024QAM(Quadrature Amplitude Modulation)modulated signal and the 2048 QAM modulated signal increases by 13.0 d B and 12.1 d B,respectively.Thirdly,the thesis presents a nonlinear coupling interference suppression algorithm for dual channel systems.It begins with an analysis of the various intermodulation components of nonlinear coupling interference in dual channel systems and introduces a dual channel nonlinear coupling interference model.A bandwidth-limited nonlinear coupling interference suppression method for the receiver is proposed to address the issue of reducing device conversion rates in large bandwidth systems.Simulation results show that the proposed method improves the EVM of the signal after interference suppression by 17.81 d B with a transmission signal bandwidth of 2 GHz,a carrier interval of 2.6 GHz,an out-of-band leakage of –31.2 d Bc,and a coupling coefficient of 0.3.This thesis proposes a receiver suppression method for linear and nonlinear coupling interference in dual channel systems.The algorithm’s feasibility is verified through simulation,providing a new solution for suppressing coupling interference in the digital domain.