Enhancement of MLD for SDM/OFDM using power imbalance of polarization and pre-phase distortion scheme

SDM/OFDM systems transmit different data using the same frequency, so it is necessary to reduce the co-channel interference for separating the simultaneously received signals. Previous studies have shown that the maximum likelihood detection (MLD) has the best BER performance. However, if the received powers of the desired symbols from different antennas are nearly the same, MLD shows poor detection property, since almost the same replicas may generate, even if the combination of the transmitted symbols are different. For enhancement of a MLD of SDM/OFDM, in this paper, we focus on a power imbalance of polarization and the pre-phase distortion scheme to diminish the same power and phase occurrence probability of the received signals.