Design of irregular LDPC codes with optimized performance-complexity tradeoff

—The optimal performance-complexity tradeoff for error-correcting codes at rates strictly below the Shannon limit is a central question in coding theory. This paper proposes a numerical approach for the minimization of decoding complexity for long-block-length irregular low-density parity-check (LDPC) codes. The proposed design methodology is applicable to any binary-input memoryless symmetric channel and any iterative message-passing decoding algorithm with a parallelupdate schedule. A key feature of the proposed optimization method is a new complexity measure that incorporates both the number of operations required to carry out a single decoding iteration and the number of iterations required for convergence. This paper shows that the proposed complexity measure can be accurately estimated from a density-evolution and extrinsicinformation transfer chart analysis of the code. A sufficient condition is presented for convexity of the complexity measure in the variable edge-degree dis...

• Type: Journal
• Year: 2010
• Where: TCOM
• Authors: Benjamin Smith, Masoud Ardakani, Wei Yu, Frank R. Kschischang
• Keywords: Complexity Measure, Long-block-length Irregular Low-density, Single Decoding Iteration, TCOM 2010