Effective code tracking system for M-ary orthogonal modulation scheme

In this paper, the tracking method for M-ary orthogonal modulation system is used for the internal synchronization system that uses square-low detector. In the system, a pair of pseudo-noise(PN) sequences which consists of the modified pseudo-ternary M-sequence and {-1, 1}-valued M-sequence is used. The modified pseudo-ternary M-sequence is a PN code which combines the {0, 1}-valued M-sequence with the Hadamard code. The S-curve characteristic of the tracking system is much the same as that of the conventional 1Δ-DLL system with {-1, 1}-valued M-sequence. Thus, the M-ary orthogonal modulation system using MPTM can use the DLL used in the DS/SS system. The following performance in channel with the Additive White Gaussian Noise (AWGN) is analyzed and evaluated; (1) The tracking error (jitter) performance and (2) The bit error rate (BER) performance that takes jitter into account. As a result, these performances are better than conventional M-ary orthogonal systems.