Erasure Codes for Space Communications: Recent Findings and New Challenges

Abstract

The use of erasure codes in space communications has proved to be promising in order to make communication more robust against both independent and correlated data losses. In particular, erasure codes are an appealing solution to provide space communications with increased reliability, especially in scenarios where large latencies make the use of automatic repeat request (ARQ) strategies problematic. In this regard, preliminary studies on the use of binary low-density parity-check (LDPC) codes under maximum likelihood (ML)/iterative (IT) decoding have been carried out showing the performance benefit they can bring over traditional schemes based on retransmissions. This paper extends the analysis conducted in previous studies towards non-binary LDPC codes. Performance assessment is carried out with respect to reliability metrics (codeword error rate) and encoding/decoding complexity, taking into consideration the limitations of space communications in terms of storage and processing capabilities. Finally, the paper sketches some design guidelines on the integration of the proposed codes into the Consultative Committee for Space Data Systems (CCSDS) protocol stack, implemented as extension of the Licklider Transmission Protocol (LTP).