Time slot-split NOMA with resource allocation in full-duplex cooperative communications

This paper presents a time slot-split non-orthogonal multiple access (TSS-NOMA) scheme for full-duplex (FD) cooperative communication systems to improve resource utilisation. Aiming at the problem of low bandwidth efficiency when pairing users, TSS-NOMA divides a complete time slot into several parts to improve the pairing process. Users can occupy all bandwidths in different slots to reduce the waste of bandwidth resources. Unlike the scheme of forwarding a single signal, TSS-NOMA decodes the information symbols of relay, and re-encodes the messages through the new power allocation factors of successfully paired users. The hybrid symbols are sent to increase the proportion of central users' own signals received by themselves, thus improving the ergodic capacity of the system. To maximise the minimum achievable rate of the system, TSS-NOMA optimises the power allocation at the base station, and the relay. The performance of TSS-NOMA is verified by simulation, where numerical results show that this scheme can achieve higher spectral, and energy efficiency.