2014 Volume 11 Issue 2 Pages 20130837
A Radix-4 Quasi-cyclic shift network (QSN) for reconfigurable QC-LDPC decoders is presented in this paper. A complexity reduction technique is described to reduce the total gate count at each stage in addition to the fact that Radix-4 logarithmic barrel shifter naturally offers less number of stages compared to Radix-2. The proposed Radix-4 QSN architecture supports various code rates and all sizes of sub matrices. Moreover, a novel Radix-4 signal generator is proposed which is particularly an essential element for reconfigurable LDPC decoders. The synthesis, placement and routing (P & R) of the proposed network is performed using TSMC 90-nm standard cell CMOS technology. The implementation results shows that the proposed network outperforms its predecessors by about 11% and 38% in terms of area and clock frequency respectively.