Multiobjective Optimization for Pre-DFT Combining in Coded SIMO-OFDM Systems

For coded SIMO-OFDM systems, pre-DFT combining was previously shown to provide a good trade-off between error-rate performance and processing complexity. Max-sum SNR and max-min SNR are two reasonable ways for obtaining these combining weights. In this letter, we employ multiobjective optimization to further reveal the suitability and limitation of these two criteria. Our results show that: 1) Neither max-sum SNR nor max-min SNR is universally good; 2) For better error-rate performance, the means for weight calculation should be adapted according to the capability of the error-correcting code used, and multiobjective optimization can help in the determination.