OFDM/SDM system using adaptive transmit phase control to mitigate co-channel interference

In order to realize a high data rate, the orthogonal frequency division multiplexing (OFDM) system using space division multiplexing (SDM) has been proposed. In the OFDM/SDM system, previous studies have shown that the maximum likelihood estimation (MLE) has the best bit error rate (BER) performance. However, if the received powers of the desired symbols from different antennas are nearly the same and the desired symbols are received with specific phase difference, MLE technique cannot work well, because almost the same replicas are generated. In order not to generate the same replicas in the MLE detection and to reduce the probability of MLE detection error, we propose an OFDM/SDM system with transmitting phase control. By using the computer simulation, we show that the proposed system can improve the BER performance compared with the system without phase control.