In two-hop relay-aided cellular networks, both half-duplex (HD) and full-duplex (FD) transmission have been\nextensively studied. FD transmission can achieve twice throughput of HD transmission, but suffers from strong\nself-interference (SI), which may not be perfectly cancelled. In this paper, a hybrid HD/FD transmission scheme in a\nrelay-aided cellular network is proposed, which not only utilizes the throughput advantage of FD but also weakens\nthe negative effect of SI. The key idea is that a relay station (RS) switches between the HD and the FD modes\nbased on the received signal-to-interference-plus-noise ratio (SINR). If the information rate of the base station\n(BS)-to-RS link is lower than a preset threshold, the RSs adopt the FD mode to guarantee the throughput;\notherwise, the RSs adopt the HD mode to reduce the negative effect of SI. As FD transmission consumes more\npower than HD transmission, we try to maximize the system energy efficiency under the system spectral efficiency\nconstraint and the transmit power constraints. It is difficult to solve this optimization problem directly, so the\nalternate optimization method is adopted to solve it, i.e., optimizing the transmit power of the BS and the transmit\npower of RSs in turn. Simulation results show that under perfect SI cancellation, the hybrid scheme can achieve\nhigher energy efficiency than the HD mode by taking the throughput advantage of FD; while under poor SI\ncancellation, the hybrid scheme can greatly weaken the negative effect of SI and achieve higher energy efficiency\nthan the FD mode.
Loading....