Super-Imposed Pilot-Aided Channel Estimation and Power Allocation for Relay Systems

Super-imposed pilots can be used as an alternative to traditional pilots that are used for channel estimation. Superimposed pilots improve bandwidth efficiency. We apply it to the amplify and forward (AF) relay systems. In this paper we give the channel estimation (CE) results, analyze the system performance, study the power allocation methods and extend our result to multi-hop relay systems. Our main contribution is that we suggest and prove the existence of minimum bit error rate (BER) as a function of pilot signal power, find the best power allocation ratio value that can reach the minimum BER, analyze parameters´ influence on the ratio value, and extend our result to multi-hop systems.