Semiconstrained Systems

Abstract—When transmitting information over a noisy channel, two approaches are common: assuming the channel errors are independent of the transmitted content and devising an errorcorrecting code, or assuming the errors are data dependent and devising a constrained-coding scheme that eliminates all offending data patterns. In this paper we analyze a middle road, which we call a semiconstrained system. In such a model, which is an extension of the channel with cost constraints, we do not eliminate the error-causing sequences entirely, but rather restrict the frequency in which they appear. We address several key issues in this study. The first is proving closed-form bounds on the capacity which allow us to bound the asymptotics of the capacity. In particular, we bound the rate at which the capacity of the semiconstrained (0, k)-RLL tends to 1 as k grows. The second key issue is devising efficient encoding and decoding procedures that asymptotically achieve capacity with vanishing er...

• Type: Journal
• Year: 2016
• Where: TIT
• Authors: Ohad Elishco, Tom Meyerovitch, Moshe Schwartz
• Keywords: Education, TIT 2016