DOI: 10.36347/sjet

Pages: 223-227

Nowadays, in high data rate wireless communication systems, the power consumption of the baseband modems is significantly affected by the channel decoder complexity, especially when codes like LDPC are used. In this paper, we propose a new type of code called Trellis-based Quasi-Cyclic (TQC)-LDPC convolution code, which is a special case of photograph-based LDPC convolution codes. The proposed TQC-LDPC convolution code can be derived from any QC-LDPC block code by introducing trellis-based convolution dependency to the code. The main advantage of the proposed TQC-LDPC convolution code is that it allows reduced decoder complexity and input granularity (which is defined as the minimum number of input information bits the code requires to generate a codeword) while maintaining the same bit error-rate as the underlying QC-LDPC block code ensemble. We also propose two related power-efficient encoding methods to increase the code rate of the derived TQC-LDPC convolution code. The newly derived short constraint length TQC-LDPC convolution codes enable low complexity trellis-based decoders and one such decoder is proposed and described in this paper (namely, QC-Viterbi).