Skip-Sliding Window Codes

Ting-Yi Wu, Anshoo Tandon, Lav R. Varshney, Mehul Motani

Abstract: Constrained coding is used widely in digital communication and storage systems. In this paper, we study a generalized sliding window constraint called the skip-sliding window constraint. A skip-sliding window (SSW) code is defined in terms of the length L of a sliding window, skip length J, and cost constraint E in each sliding window. Each valid codeword of length L+kJ is determined by k+1 windows of length L where window i starts at (iJ+1)th symbol for all non-negative integers i such that i ≤ k; and the cost constraint E in each window must be satisfied. In this work, two methods are given to enumerate the size of SSW codes. Using the proposed enumeration methods, the noiseless capacity of binary SSW codes is determined and observations such as greater capacity than other classes of codes are made. Moreover, some noisy capacity bounds are given. SSW coding constraints arise in various applications including simultaneous energy and information transfer.