Debugging Trellis Decoding of Augmented RAC Array Codes Using a Visual Tool

Two-dimensional (2D) row and column (RAC) codes are constructed from single parity check (SPC) component codes. Parity check positions of a RAC code can be augmented to improve code rate, resulting augmented RAC (ARAC) code. The augmentation process can be conducted on only row-parity check positions (ARAC-R), or on both row/column positions (ARAC-RC). A visual tool for debugging the process of Viterbi algorithm (VA) decoding of these codes has been designed and implemented. The ARAC code parameters can be selected through a pull-down menu and accordingly a trellis diagram is constructed. Based on the received data, branch-metrics, path-metrics, and surviving path details all can be visually viewed on the trellis diagram. The tool provides an interface for introducing errors at specific array positions and their effect on output sequence can be easily determined