A Novel Class of Quadriphase Zero-Correlation Zone Sequence Sets

The present paper introduces the construction of quadriphase sequences having a zero-correlation zone. For a zero-correlation zone sequence set of N sequences, each of length l, the cross-correlation function and the side lobe of the autocorrelation function of the proposed sequence set are zero for the phase shifts τ within the zero-correlation zone z, such that |τ | ≤ z (τ , 0 for the autocorrelation function). The ratio N (z+1) l is theoretically limited to one. When l = N (z + 1), the sequence set is called an optimal zero-correlation sequence set. The proposed zerocorrelation zone sequence set can be generated from an arbitrary Hadamard matrix of order n. The length of the proposed sequence set can be extended by sequence interleaving, where m times interleaving can generate 4n sequences, each of length 2m+3n. The proposed sequence set is optimal for m = 0, 1 and almost optimal for m > 1. key words: optimal zero-correlation zone, quadriphase, QS-CDMA, ASCDMA