Cooperative Multi-Antenna Relaying in Heterogeneous Networks

In this paper, we investigate the performance of heterogeneous networks with multi-antenna cooperative relays. Specifically, threshold-based maximum ratio combining (MRC) and selection combining (SC) schemes are adopted for decoding at the relays and the end-to-end (E2E) error rate performance is analyzed by assuming a Nakagami channel model. Numerical results show that the deployment of multi-antennas can reduce the number of required relay nodes, and thus significantly reduce the system cost. On the other hand, the selection of optimal decoding threshold depends on the number of relay nodes, number of antennas, as well as the average SNR value at the receiver. It is also demonstrated that when the BER requirement is not high, the SC relaying scheme is sufficient to provide satisfactory performance, such that the complexity of relays can be effectively reduced.