On efficient m-ary q-th order spectral-null codes
Luca G. Tallini · 2002
Let S(N,q,m) be the set of all words of length N over the m-ary alphabet /spl Phi//sub m/={-(m-1),-(m-3),...,+(m-3),...,+(m-1)} having a q-th order spectral-null at zero frequency. Any subset of S(N,q,m) is a m-ary q-th order spectral-null code. This paper presents a new efficient method to encode k information m-ary digits into a m-ary second-order spectral-null code whose redundancy is /spl les/3log/sub m/k+O(loglogk); for all values of m/spl ges/2.