Performance analysis of successive di-state full-duplex cooperative wireless cellular networks

Abstract

This paper examined uplink and downlink di-state (primary and secondary) situations to build the theoretical and practical realization of a bidirectional cooperative wireless cellular network. In the primary scenario, full-duplex (FD) base stations support two sets of half-duplex (HD) users, where the transmitter (uplink) and receiver (downlink) respectively. Each uplink transmitted signal is rotated in a variant phase through a set of scalars known to the base stations before transmission. The signal from the transmitter ensures the reconfigurable receiver antennas at the base stations can configure the received signal as decoded signals. The proposed work exposed strong self and inter-user interference from the transmitter during demonstrating FD wireless communication mode that destroyed network functionality at the base stations. The occurred self-interference signals from the transmitter are neutralized using precoding and beam-forming technique. During the secondary scenario, decoded base station signals are independently encoded and transmitted to the downlink users. Base stations aid the inter-user interference management by precoding the uplink transmission data and forwarding it to the downlink users. Consequently, the inter-user interference signals are aligned using the span interference alignment technique. A proposed cooperative additional receiver (listener U1) can decode the desired signals and helps in recovering and reconstructing the interference signals. This proposed work completely characterized and evaluated the degree of freedom (DoF) for unknown channel state information at the transmitter (CSIT); whereas achievable lower and upper bound DoF are demonstrated for the partial CSIT. At last, the analytical and simulation results reveal the sum of DoF improvement for unknown and partial CSIT.