ENHANCING BEST SOURCE SELECTOR OUTPUT QUALITY WITH FEC

Abstract

Best Source Selectors are now widely used to deal with the increasing need for range coverage in flight test activities. They are known to provide higher telemetry link availability and reliability. The Maximum Likelihood Bit Detection algorithm is commonly used to perform bit by bit combining in order to minimize the bit error probability. However, it requires at least three Data Quality Encapsulated streams with DQM information. Additionally, it does not exploit the benefits of Forword Error Correction algorithms such as LDPC codes since a basic best frame selection is usually implemented. This paper presents a new approach to improve the combined output quality when FEC frames are provided, starting from two DQE streams using FEC algorithms after combining. We present full system simulation results with AWGN channels, showcasing 1dB gains for two streams and higher than 3dB for more, as compared to the traditional MLBD combiner.