Recent findings on erasure codes for space communications

Abstract

SUMMARYImplementation of automatic repeat request strategies is the main reliability option available in the Consultative Committee for Space Data Systems protocols to support data communications in deep‐space missions. The large latency often experienced in such scenarios, however, penalizes the efficiency of retransmissions, making the overall applicability of automatic repeat request problematic. On the contrary, the use of erasure codes is a more appealing solution to mitigate packet losses. In this regard, preliminary studies on the use of binary low‐density parity‐check codes under maximum likelihood/iterative decoding have already shown the performance benefit they can bring with respect to traditional schemes based on retransmissions. This paper extends the analysis conducted in previous studies toward non‐binary low‐density parity‐check codes. Performance assessment is carried out with respect to reliability metrics (codeword error rate) and encoding/decoding complexity. Finally, the integration of erasure codes into the Consultative Committee for Space Data Systems protocol stack is discussed, by presenting the implementation in the Licklider Transmission Protocol. Copyright © 2014 John Wiley & Sons, Ltd.

Distributed Rateless Codes with Unequal Error Protection Property for Space Information Networks

“…Decoding overhead γ SF [7] XOR [7] SLRC [14] eep−DURC EWF MIB [18] WRC LIB [17] WRC MIB [17] (a) (b) Figure 5. Decoding error rate versus the total overhead at the destination: (a) various DRC schemes; and (b) various UEP schemes.…”

“…In 2014, Consultative Committee for Space Data Systems (CCSDS) released an experimental specification of long erasure correcting (LEC) codes for near earth and deep-space communications [3], in which near-optimum fixed code rate Irregular-Repeat-Accumulate (IRA) codes are proposed. In [4], a joint design of the CCSDS file delivery protocol (CFDP) and IRA codes is discussed, and such erasure codes can be decoded efficiently with the Maximum-Likelihood algorithm [5], and the code rate can be selected from several values [6,7].…”