Almost Difference Set Pairs and Ideal Three-Level Correlation Binary Sequence Pairs

The Constructions of Almost Binary Sequence Pairs and Binary Sequence Pairs with Three-Level Autocorrelation

Binary Sequence Pairs with Two-Level Correlation and Cyclic Difference Pairs

SUMMARY We investigate binary sequence pairs with two-level correlation in terms of their corresponding cyclic difference pairs (CDPs). We define multipliers of a cyclic difference pair and present an existence theorem for multipliers, which could be applied to check the exis-tence/nonexistence of certain hypothetical cyclic difference pairs. Then, we focus on the ideal case where all the out-o...

Design of Almost Perfect Complementary Sequence Pairs

Sequences with very low out-of-phase auto-correlation and cross-correlation function are widely used for synchronization in mobile communication and multimedia systems where reliable data transmissions are required. For optimum detection, synchronization sequences usually have out-of-phase correlation values that are very low or zero. However sequences with ideal correlation function are very r...

Sequence pairs with asymptotically optimal aperiodic correlation

The Pursley-Sarwate criterion of a pair of finite complex-valued sequences measures the collective smallness of the aperiodic autocorrelations and the aperiodic crosscorrelations of the two sequences. It is known that this quantity is always at least 1 with equality if and only if the sequence pair is a Golay pair. We exhibit pairs of complex-valued sequences whose entries have unit magnitude f...

All Pairs Almost Shortest Paths

Let G = (V;E) be an unweighted undirected graph on n vertices. A simple argument shows that computing all distances in G with an additive one-sided error of at most 1 is as hard as Boolean matrix multiplication. Building on recent work of Aingworth, Chekuri and Motwani, we describe an ~ O(minfn3=2m1=2; n7=3g) time algorithmAPASP2 for computing all distances in G with an additive one-sided error...