Tsutomu Moriuchi

Balanced nonbinary sequences with good periodic correlation properties obtained from modified Kumar-Moreno sequences

Kumar and Moreno (see ibid., vol.37, no.3, p.603, 1991) presented a new family of nonbinary sequences which has not only good periodic correlation properties but also the largest family size. First, the unbalanced properties for Kumar-Moreno sequences are pointed out. Second, a new family of balanced nonbinary sequences obtained from modified Kumar-Moreno sequences is proposed, and it is shown that the new family has the same optimal periodic nontrivial correlation as the family of Kumar-Moreno sequences and consists of the balanced nonbinary sequences. It is also shown that the cost of making sequences balanced is a decrease of the family size in addition to the condition that n is an even number. In particular, let the length of Kumar-Moreno sequences and the new sequences be the same and equal to p/sup n/-1 with n even, then the family size of the new sequences is p/sup n/2/ which is much smaller than p/sup n/, that of Kumar-Moreno sequences. >

A set of binary sequences obtained from 4 preferred m-sequences

We have an interest in a set of binary sequences with large family size and lower maximum correlation values for the CDMA system. In this paper, we show the new sets of binary sequences with large family size, whose period of the sequences is equal to 2m-1, m an integer, obtained from 4 preferred m-sequences. The nontrivial maximum correlation value and family size of our sets are shown to have 22 times and 22m times, respectively, as large as those of Gold family.

GF(q) sequences of period q/sup n/-1 with maximum linear complexity and maximum order complexities for minimum changes of m-sequences

Among GF(q) sequences of period N=q/sup n/-1 m-sequences are known to have minimum linear complexity (LC) of n. LCs for minimum changes of m-sequences are shown to be maximum, i.e. N. First it is shown that this maximum LC property is not peculiar to m-sequences if q/spl ne/2 or N is not prima. Secondly maximum order complexities (MOC) for minimum changes of m-sequences have reasonable values between n and 2n.<<ETX>>