Performance of DTC-OFDM of the LMS Channel in Ka Band

Differential turbo coded OFDM(DTC-OFDM) scheme was presented, together with a differential soft-detection method for Ka-band satellite communications. DTC-OFDM combines Turbo codes, orthogonal frequency division multiplexing (OFDM) modulation and differential detection, which has the advantages of high spectrum efficiency and suppression of multipath fading, jamming and noise. The DTC-OFDM system model and Ka-band satellite communication system simulation model have been found, then we also analyzed the bit error rate (BER) performance of OFDM with N-QAM modulation technique. The results show that DTC-OFDM system gives the best performance compared to convolutional coded (CC) and trellis coded OFDM systems. In the case of 256-QAM, DTC- OFDM system can provide 1 dB coding gain at a BER of 10^-4 compared with TCM-OFDM system and 4 dB compared with CC-OFDM system.