Parallel LDPC Decoding on a GPU using OpenCL and Global Memory for Accelerators

Abstract

This paper introduces a parallel software decoder of Low Density Parity Check (LDPC) codes with an Open Computing Language (OpenCL) framework including Global Memory for ACcelerators (GMAC). The LDPC code is one of the most popular and strongest error correcting codes for mobile communication systems. OpenCL is an open standard programming framework that supports programming languages and application programming interfaces (APIs) for heterogeneous platforms. GMAC is a software implementation of Asymmetric Distributed Shared Memory (ADSM) that maintains a shared logical memory space for the host to access memory objects in the physical memory of an OpenCL device. In this paper, we parallelize the iterative LDPC decoding steps on a graphics processing unit (GPU) using OpenCL. To improve the performance of the proposed decoder, data transfer optimization techniques between the host and the GPU including pre-pinned OpenCL memory objects for GMAC are applied. In terms of the entire decoding time, the speedup of the proposed LDPC decoder over a conventional OpenCL implementation is 1.28.