Fixed-Data-Rate Power Minimization Algorithm for OFDM-Based Power-Line Communication Networks

In this paper, we present a suboptimal integer bit allocation algorithm that minimizes power output for given user demands in multiuser orthogonal frequency-division multiplexing (OFDM) systems implemented in downlink transmission of power-line communication (PLC) networks. Assuming complete knowledge of a channel and the predetermined data rates for every user, the presented algorithm solves the power minimization problem analytically. The simulation results have shown significant advantages of this approach, especially in comparison with algorithms that deal with the problem of user data rate demands in an iterative manner. Compared to iterative algorithms, the proposed algorithm proves to be a much more effective solution regarding processing time and computational complexity. In addition, the losses in its power allocation efficiency due to its suboptimal approach remain very small in cases where the number of users does not exceed half the number of available subchannels.