Effect of device accuracy on analog self-interference cancellation performance in full duplex system

Abstract

In a full duplex transceiver, which transmits and receives simultaneously at the same frequency, since the self-interference from the transmitted antenna to the received antenna is strong, the self-interference cancellation in the analog domain is required. However, subject to the limited accuracies of devices, the theoretical analysis of the analog self-interference cancellation has a large difference with the experimental performance, and can not be applied directly in the practical application. In this paper, the effect of accuracies of the analog devices, such as the tunable attenuator and phase shifter, on the self-interference cancellation performance of a full duplex transceiver is analyzed, i.e., the closed-form expressions of the self-interference cancellation ratio with different accuracies of analog devices are shown. By analysis and simulation, the self-interference cancellation performs worse as the step sizes of the tunable attenuator and phase shifter increase.