Inter-User Interference Cancellation Scheme for 5G-Based Dynamic Full-Duplex Cellular System

Improving spectral efficiency is an important issue for the next generation of the 5th generation mobile communication (5G) systems. Full-duplex cellular (FDC) and dynamic-FDC (DDC) systems based on the 5G signal format (5G-FDC and 5G-DDC) have gained substantial attention for introducing in-band full-duplex (IBFD) into 5G. However, self-interference (SI) at a base station (BS) and inter-user interference (IUI) in user equipment (UE) are significant hurdles in implementing FDC and DDC systems. This study proposes an IUI cancellation (IUIC) scheme based on successive interference cancellation tailored to the signal configuration and channel coding of 5G. Additionally, we introduce user scheduling and adaptive modulation algorithms for 5G-DDC. We evaluate the proposed schemes using link- and system-level simulations. The results demonstrate a remarkable 40 dB reduction in IUI with a 3.4 dB decline in reception quality. Furthermore, our IUIC method reduces the IUI of close-distance UE pairs, expands the candidate UE pairs for IBFD operation, and significantly enhances the IBFD application ratio in the downlink slot by 51.0% compared to conventional 5G-DDC. Moreover, the gain of the uplink average throughput increases by 11.4% when the BS and UE transmission powers are at their maximum.