DMT Analysis and Optimization for OFDM-Based Relaying Systems with Linear Detector

In this paper, we consider a single-antenna OFDM-based relaying system over frequency selective fading channels employing subcarrier grouping and linear constellation precoding at the source node, and linear detection at the destination node. We derive the closed-form expressions of the diversitymultiplexing tradeoff (DMT) relation, and develop the optimal symbol loading strategy (the optimal number of symbols assigned to each group), and the optimal grouping strategy (the optimal partition of the subcarriers) to achieve the optimum DMT performance. Simulation results are presented to verify our theoretical analysis.