Topology-aware macro diversity handover technique for IEEE 802.16j multi-hop cellular networks

Macro diversity handover (MDHO) is the process by which a mobile station (MS) maintains connection with two or more access stations called a diversity set. In this study, the authors propose a topology-aware MDHO technique for time division duplex (TDD)-orthogonal frequency division multiple access (OFDMA)-based interference-limited multi-hop cellular networks. The proposed MDHO receives all the data signals transmitted by the diversity set members of the MS. It ensures that the topology of the diversity set members is always fully exploited. The efficiency of the proposed MDHO is validated using a mathematical model and computer simulation. The performance evaluation is carried out for different relay station (RS) transmitted powers. Evaluation results show that the proposed MDHO significantly outperforms the conventional MDHO. Over the MDHO regions in which the diversity set members are multi-hop relay base station (MR-BS) and RS, the proposed MDHO offers a carrier to interference and noise ratio gain and a spectral efficiency gain of as much as 4.5 dB and 0.85 bps/Hz, respectively, compared to the conventional MDHO.