This paper presents a numerical analysis of the communication performance of two aligned channel with uniform circular arrays carrying orbital angular momentum (OAM). The direct communication of different OAM modes between the transmitting and receiving OAM arrays is calculated by using full-wave simulation in the method of moments. Moreover, due to the close location of such two OAM channels, the noise signals are increased because of the cross talks from the adjacent channel. The signals of the transmitted modes are not affected significantly. The effects of the communication distance and the gap distance between two channels are also interpreted in this paper.