Generalized LDPC Codes for Deep Space Communication Systems

Since deep space channel coding requires both high coding gain and low error floor, a Generalized LDPC code for specific use in deep space communications is proposed in this paper. The new GLDPC is constructed from a regular LDPC generated from modified PEG algorithm, where BCH is used as component code instead of the SPCs in the regular LDPC, which we call PEG-GLDPC. PEG-GLDPC is decoded using iterative decoding scheme with a combination of SISO decoding of BCH, more specifically, trellis-based Log-MAP is employed on BCH and then BP algorithm is used on PEG-GLDPC. Simulation results over an AWGN channel indicate that such a code design and decoding approach leads to excellent performance, which is better than that of traditional LDPC and classic GLDPC.