High parallel variation Banyan network based permutation network for reconfigurable LDPC decoder

Permutation network plays an important role in the reconfigurable QC-LDPC decoder for most modern wireless communication systems with multiple code rates and various code lengths. In this paper, we propose the variation Banyan network (VBN) based permutation network architecture for the reconfigurable QC-LDPC decoders and give the control signal generating algorithm for cyclic shift. Through introducing the bypass network, we put forward the nonblocking scheme for any input number and shift number. In addition, the optimized VBN is proposed for WiMAX and WiFi standard, which can shift at most 4 groups of input data, and greatly reduce the hardware complexity. The synthesis results using the 90nm technology demonstrate that the proposed permutation network can be implemented with the gate count of 18.3k and the frequency of 600 MHz.