Asymptotic Gilbert–Varshamov Bound on Frequency Hopping Sequences
Xianhua Niu, Chaoping Xing, Chen Yuan · IEEE Transactions on Information Theory · 2019
Given a q-ary frequency hopping sequence set of length n and size M with Hamming correlation H, one can obtain a q-ary (nonlinear) cyclic code of length n and size nM with Hamming distance n-H. Thus, every upper bound on the size of a code from coding theory gives an upper bound on the size of a frequency hopping sequence set. Indeed, all upper bounds from coding theory have been converted to upper bounds on frequency hopping sequence sets [1]. On the other hand, a lower bound from coding theory does not automatically produce a lower bound for frequency hopping sequence sets. In particular, the most important lower bound, the Gilbert-Varshamov bound in coding theory, has not been transformed to a valid lower bound on frequency hopping sequence sets. The purpose of this paper is to transform the Gilbert-Varshamov bound from coding theory to frequency hopping sequence sets by establishing a connection between a special family of cyclic codes (which are called hopping cyclic codes in this paper) and frequency hopping sequence sets. We provide two proofs of the Gilbert-Varshamov bound. One is based on a probabilistic method that requires advanced tool- martingale. This proof covers the whole rate region. Another proof is purely elementary but only covers part of the rate region.