Power Allocation in Concatenated Trellis Coded Modulation

In this paper, power loading algorithms are presented for limited diversity fading channels with channel state information at the transmitter. Limited diversity channels are those that offer moderate levels of diversity (about 3-5) such as those encountered in orthogonal frequency division multiplexing (OFDM) based indoor wireless networks. We propose our ideas in the framework of a recently proposed coding approach for limited diversity channels although key aspects of the paper are valid for any coding scheme. We develop the optimal transmitter loading algorithm and also a low complexity suboptimal algorithm based on a linear objective function that maximizes the effective signal to noise ratio of the coded system. We compare the performances of different coding approaches with the proposed power allocation algorithms. Simulation results supporting the ideas presented in this paper are given.