Combined Coding And Modulation Using Runlength Limited Error Correcting Codes

Abstract

Run Length Limited (RLL) codes are widely used in data transmission/storage systems, such as digital  magnetic recording and optical storage. However, they are vulnerable when used in channel transmission and  are easily corrupted by noise. Run Length Limited/Error correcting Codes (RLL/ECCs) have been designed so that they retain their original key property while being suitable for channel transmission. In this paper we  propose a Combined Coding and Modulation (CCM) scheme employing RLL/ECCs and MPSK modulation as well as RLL/ECC codes and BFSK/MPSK modulation with a view to optimise on channel bandwidth. The CCM codes and their trellis are designed and their error performances simulated in AWGN and slow Rayleigh fading  channel. The superior performance of the proposed CCM schemes is also demonstrated.