Date Added: Dec 2009
Super-imposed pilots can be used as an alternative to traditional pilots that are used for channel estimation. Superimposed pilots improve bandwidth efficiency. The authors apply it to the Amplify and Forward (AF) relay systems. In this paper the authors give the Channel Estimation (CE) results, analyze the system performance, study the power allocation methods and extend the result to multi-hop relay systems. The main contribution is that they 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 the result to multi-hop systems.