Low Power QC-LDPC Decoder Based on Token Ring Architecture

The article presents an implementation of a low power Quasi-Cyclic Low-Density Parity-Check (QC-LDPC) decoder in a Field Programmable Gate Array (FPGA) device. The proposed solution is oriented to a reduction in dynamic energy consumption. The key research concepts present an effective technology mapping of a QC-LDPC decoder to an LUT-based FPGA with many limitations. The proposed decoder architecture uses a distributed control system and a Token Ring processing scheme. This idea helps limit the clock skew problem and is oriented to clock gating, a well-established concept for power optimization. Then the clock gating of the decoder building blocks allows for a significant reduction in energy consumption without deterioration in other parameters of the decoder, particularly its error correction performance. We also provide experimental results for decoder implementations with different QC-LDPC codes, indicating important characteristics of the code parity check matrix, for which an energy-saving QC-LDPC decoder with the proposed architecture can be designed. The experiments are based on implementations in the Intel Cyclone V FPGA device. Finally, the presented architecture is compared with the other solutions from the literature.