Evaluation of cell selection algorithms in LTE-Advanced relay networks

The concept of relay has been introduced in LTE-Advanced as a promising approach to enhance network performance. Because of the diversity introduced by deploying relays to a purely macro network, the conventional cell selection schemes do not perform well, leading to noticeable throughput degradation for some of the users. An algorithm attempting to address the issue is the use of data rate mapped from Reference Signal Received Power (RSRP) as the cell selection criterion. This algorithm, however, introduces an extra interference problem. We therefore describe an additional interference avoidance (IA) mechanism to enhance it. Performance evaluation and analysis are carried out to gain insights on the enhanced algorithm and two additional algorithms, both developed in this paper, to demonstrate their effectiveness in improving the throughput. Simulation results show that for relay-enabled networks the new algorithms based on data rates obtained directly from RSRP and the Reference Signal Received Quality (RSRQ) outperform the algorithm based on RSRP with offset. Moreover, the interference issue is well dealt with via the implementation of additional IA.