Analysis of the bi-orthogonal modulation system using two different inner sequences

In this paper, a frame synchronization method for the bi-orthogonal modulation system is proposed. The bi-orthogonal modulation system is an attractive system because the bit error rate (BER) performance improves as the number of sequences, which is employed in the system, increases under an additive white gaussian noise environment. Frame synchronization of the bi-orthogonal modulation system is difficult, however, because the bi-orthogonal modulation system uses several sequences for data transmission. In this paper, we show a frame synchronization system that utilizes two different inner sequences. This system enables the receiver to extract the frame timing from the received signal by using the conventional delay lock loop in total independence from the transmitted sequence. In this paper, we analyze the tracking performance of the proposed frame synchronization system. Moreover, the BER performance considering the tracking performance is investigated. As the result, it is found that there is a trade-off between the BER performance and the tracking performance. Furthermore, it is shown that the BER performance of the proposed system is better than that of binary phase shift keying by 1 [dB] at 10^-5 BER