Viterbi Decoding for Satellite and Space Communication

TLDR

The study proposes using convolutional coding with Viterbi decoding and binary phase‑shift keying to achieve reliable communication on power‑limited satellite and space channels, and investigates how decoder complexity and cost parameters influence performance. The authors implement the system, compare hard receiver quantization with 4‑ and 8‑level soft quantization, analyze the impact of decoder complexity and cost, and evaluate performance degradation from imperfect carrier phase coherence relative to an uncoded system. Theoretical and simulation results show optimal short constraint‑length codes across various lengths and rates, a 2‑Mbit/s constraint‑length‑7 Viterbi decoder’s performance versus complexity, and a comparison of Viterbi and sequential decoding for different system requirements.

Abstract

Convolutional coding and Viterbi decoding, along with binary phase-shift keyed modulation, is presented as an efficient system for reliable communication on power limited satellite and space channels. Performance results, obtained theoretically and through computer simulation, are given for optimum short constraint length codes for a range of code constraint lengths and code rates. System efficiency is compared for hard receiver quantization and 4 and 8 level soft quantization. The effects on performance of varying of certain parameters relevant to decoder complexity and cost is examined. Quantitative performance degradation due to imperfect carrier phase coherence is evaluated and compared to that of an uncoded system. As an example of decoder performance versus complexity, a recently implemented 2-Mbit/s constraint length 7 Viterbi decoder is discussed. Finally a comparison is made between Viterbi and sequential decoding in terms of suitability to various system requirements.