Analysis and performance evaluation of new coding options for space telecommand links ‐ Part I: AWGN channels

Abstract

We investigate and compare, over the additive white Gaussian noise channel, different options for updating the error correcting code currently used in space mission telecommand links. Besides some more consolidated proposals, using low-density parity-check codes, we characterize and assess the performance of alternative schemes, based on parallel turbo codes and soft-decision decoded Bose-Chaudhuri-Hocquenghem (BCH) codes. The analysis considers relevant metrics like the codeword error rate, the frame error rate, and the undetected frame error rate. The considered codes include binary and non-binary low-density parity-check codes, parallel turbo codes and extended BCH codes, with different decoding algorithms. The complexity of the various schemes and possible limits for their application are considered and discussed. Several numerical examples are provided. International Parallel turbo codes are already included in the CCSDS Telemetry Recommendation [13] but with different code parameters. The CCSDS turbo encoder scheme is depicted in Figure 3. In the figure we Figure 3. Consulative Committee for Space Data Systems parallel turbo encoder.

Analysis and performance evaluation of new coding options for space telecommand links – part II: jamming channels

“…We show that some hierarchy established among the codes looking at the performance over the AWGN channel can change for some scenarios, as a function of the jamming parameters. These results, combined with those presented in , can provide useful elements to orientate the choice of a code, or a family of codes, able to work properly in practical space channels.…”

“…In this paper, we focus on a space TC link with a base‐band section developed in agreement with the CCSDS recommendation , described in more detail in the companion paper . Most TC messages are very short, and then the system requires short codeword‐length coding schemes.…”

“…The code used by the current recommendation is the BCH(63, 56) code, with hard‐decision decoding. Advanced coding schemes like LDPC codes, parallel turbo codes, and soft‐decision decoded BCH codes with codeword length 128≤ n ≤512 are currently under study in CCSDS working groups for improving the TC link performance.…”

“…In view of updating the error correcting codes for telecommand (TC) space links, a number of new options, consisting of binary and non‐binary low‐density parity‐check (LDPC) codes, parallel turbo codes, and even extended Bose‐Chaudhuri‐Hocquenghem (BCH) codes, have been recently proposed. In the companion paper , these codes have been investigated over the additive white Gaussian noise (AWGN) channel. This kind of channel, however, is too simple for covering many practical scenarios.…”

On the use of ordered statistics decoders for low-density parity-check codes in space telecommand links

“…In order to achieve higher coding gains, new advanced coding schemes have been designed and evaluated [9]. After a long campaign of simulations and comparisons, two short binary LDPC codes have emerged as the most attractive candidates.…”