A new technique for efficient encoding of LDPC codes based on the known concept of Approximate Lower Triangulation (ALT) is introduced. The greedy permutation algorithm is presented to transform parity-check matrices into an Approximate Lower Triangular (ALT) form with minimum “Gap”. A large girth, which is known to guarantee good decoding performance, is shown (for ...

The authors describe the FPGA-based supercomputer Maxwell built by the FPGA high-performance computing alliance at the University of Edinburgh. Winner of the silver medal in the BT Flagship Award for Innovation at the 2007 British Computer Society Awards, Maxwell is a general-purpose 64 FPGA computer designed for high-performance parallel computing. This paper describes the machine ...