On the Impact of Efficient Power Allocation in Pilot Based Channel Estimation Techniques for Multicarrier Systems

The use of pilot signals for the purpose of channel estimation in multicarrier systems does not only consume bandwidth but also signal power that could otherwise be invested in the information symbols to be transmitted. The aim of this paper is to investigate the issue of optimal transmitter power distribution between the pilot and information signals and evaluate its impact on the performance of multicarrier systems. It will be shown that the optimal power distribution is primarily influenced by the ratio of number of pilots to the total number of subcarriers used. An optimal pilot power allocation as a function of this ratio will be proposed for both MPSK and MQAM systems taking into account channel estimation errors