NASA GSFC-STD-9100, LOW DENSITY PARITY CHECK CODE FOR RATE 7/8 (RELEASE PENDING) (1 MAY 2006)

NASA GSFC-STD-9100, LOW DENSITY PARITY CHECK CODE FOR RATE 7/8 (RELEASE PENDING) (1 MAY 2006)., The purpose of this document is to establish a common GSFC channel coding standard for bandwidth efficient spacecraft communications. Currently many Goddard missions use the concatenated Reed-Solomon and convolutional coding technique for space to ground links. While this standard has served NASA well in the past it is bandwidth inefficient. The need GSFC-STD-9100, Low Density Parity Check Code for Rate 7/8. for bandwidth efficiency has prompted the Microwave and Communication Systems Branch (Code 567) to search for a new channel code that require less bandwidth without paying a heavy penalty in power requirement and complexity. This document details the result of that search. It gives a technical description of this new channel coding called low density parity check (LDPC) coding (Section 5). A description of the baselined LDPC code is presented in Section 6 and it’s encoding in Section 7. However, the baselined code needs to be modified to ease implementations for current space and ground systems. This modification is the proposed standard and is described in Section 8. Section 9 outlines synchronization issues and the Sections 12 and 13 of the Appendices discusses complexity issues and performance testing respectively. The reader is assumed to have a basic understanding of channel coding theory (linear algebra also) and digital communications. (The reader is encouraged to review [7] for an overview of linear block codes).