Performance Results for a Hybrid Coding System

Abstract

Computer simulation studies of the hybrid pull-up bootstrap decoding algorithm hive -been conducted using a constraint length 24, nonsystematic, rate 1/2 convolutional code for the symmetric channel with both binary and 8-level quantized outputs. Computational performance was used to measure the effect of several decoder parameters and determine practical operating constraints. Results reveal that the track length may be reduced to 500 information bits with small degradation in performance. The optimum number of tracks per block was found to be in the range of 7 to 11. An effective technique was devised to efficiently allocate computational effort and identify reliably decoded data sections. Long simulations indicate that a practical bootstrap decoding configuration has a computational performance about 1.0 dB better than sequential decoding and an output bit error rate about 2.5 x10⁻⁶ near the R(comp) point.