Delay-Limited Optimal Bit Loading Algorithm for OFDM Systems over Correlated Fading Channels

This paper explores an optimal bit loading algorithms for a multicarrier system. Specifically, we study the trade-offs between the aggregate bit error rate (BER) of an orthogonal frequency division multiplexing (OFDM) system and the buffering delay of the packets in a transmission buffer. The bit loading framework is formulated as a Markov decision process (MDP) and an optimal loading policy which minimizes the aggregate BER while meeting a target delay constraint is obtained via equivalent linear programming (LP) methodology. The complexity of finding the optimal loading policy and its’ implementation issues are described briefly. Selected numerical examples show that as the number of subcarriers increases in the system, the delay-limited aggregate BER decreases.