Performance Evaluation of Low Density Parity Check Forward Error Correction in an Aeronautical Flight Environment

Abstract

In some flight test scenarios the telemetry link is noise limited at long slant ranges or during signal fade events caused by antenna pattern nulls. In these situations, a mitigation technique such as forward error correction (FEC) can add several decibels to the link margin. The particular FEC code discussed in this paper is a variant of a low-density parity check (LDPC) code and is coupled with SOQPSK modulation in the hardware tested. This paper will briefly cover lab testing of the flight-ready hardware then present flight test results comparing a baseline uncoded telemetry link with a LDPC-coded telemetry link. This is the first known test dedicated to this specific FEC code in a real-world test environment with flight profile tailored to assess the viability of an LDPC-coded telemetry link.