Scaling, Offset, and Balancing Techniques in FFT-Based BP Nonbinary LDPC Decoders

An analysis of finite precision effects in nonbinary mixed-domain low-density parity-check decoders is presented. It is shown how improved decoding performance can be achieved by using an offset-based method and proper scaling techniques. In addition, a novel fast Fourier transform (FFT)-based belief propagation (BP) decoder architecture is proposed which balances the computational load between processing units. The results show a 47% reduction in the number of required field-programmable gate array slices compared to a standard FFT-based BP architecture.