UCCA-OAM通信系统中的双模块干扰消除方案OA

Orbital angular momentum(OAM)is a technique that provides additional degrees of freedom to improve the spectral efficiency of wireless communication.However,its application typically requires strict alignment between the transmitting and receiving antennas to maintain modal orthogonality.Considering that when using misaligned concentric circle UCA to generate and receive OAM beams,there is not only modal interference caused by misaligned single-ring UCA,but also array interference among different UCAs in the concentric circle,this paper combines the OAM multiplexing generated by uniform circular array(UCA)antennas with multiple-input multiple-output(MIMO)technology to form a uniform concentric circular array orbital angular momentum(UCCA-OAM)communication system.In order to further improve the performance of the OAM communication system,this paper proposes a uniform concentric circular array orbital angular momentum(UCCA-OAM)multiplexing transmission system in the case of unaligned.This system uses multiple concentric circles UCA as the transmitting and receiving ends,and at the same time takes advantage of the benefits of OAM multiplexing to achieve signal multiplexing through discrete Fourier transform processing.In the unaligned UCCA-OAM communication system,when transmitting OAM beams,there exists not only inter-modal interference of single-ring UCA,but also inter-array interference of multi-ring UCA.Based on this,this paper proposes a dual-module interference cancellation scheme to approximately eliminate modal interference and array interference.Firstly,the modal interference caused by the misalignment of single-ring UCA is approximately eliminated through the beam control scheme based on phase compensation.Then,according to the inverse operation of the four-block matrix,a progressive block matrix inverse operation is proposed to eliminate the array interference caused by multi-ring UCA,thereby completing the dual-module interference elimination scheme based on the progressive block matrix inverse operation.Experimental results demonstrate that the proposed dual-module interference cancellation scheme effectively suppresses both modal and array interference,thereby improving the communication performance of the UCCA-OAM system.