Relaying and base station cooperation: A comparative survey for future cellular networks

We develop a unified framework to investigate the performance of future cellular networks with relays and/or co-ordinated multipoint (CoMP) transmission. Based on this framework, we study the benefits of CoMP and relaying in a realistic setup. We consider imperfect channel knowledge, different power levels, and simple (thus practically relevant) cooperation schemes with different complexity: non-cooperative reference, decode-and-forward relaying with relay selection, base station cooperation with block zero-forcing (coherent joint transmission), and a combination of relaying and CoMP. Based on computer simulations, we compare the different schemes with respect to performance, robustness, complexity, and required transmit power.