Open Access Research

Scheduling parity checks for increased throughput in early-termination, layered decoding of QC-LDPC codes on a stream processor

JaWone A Kennedy and Daniel L Noneaker*

Author Affiliations

Holcombe Department of Electrical and Computer Engineering, 305 Fluor Daniel Engineering Innovation Building, Clemson University, Clemson, SC 29634, USA

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EURASIP Journal on Wireless Communications and Networking 2012, 2012:141  doi:10.1186/1687-1499-2012-141

Published: 12 April 2012

Abstract

A stream processor is a power-efficient, high-level-language programmable option for embedded applications that are computation intensive and admit high levels of data parallelism. Many signal-processing algorithms for communications are well matched to stream-processor architectures, including partially parallel implementations of layered decoding algorithms such as the turbo-decoding message-passing (TDMP) algorithm. Communication among clusters of functional units in the stream processor impose a latency cost during both the message-passing phase and the parity-check phase of the TDMP algorithm with early termination; the inter-cluster communications latency is a significant factor in limiting the throughput of the decoder. We consider two modifications of the schedule for the TDMP algorithm with early termination; each halves the communication required between functional-unit clusters of the stream processor in each iteration. We show that these can provide a substantial increase in the information throughput of the decoder without increasing the probability of error.

Keywords:
layered decoding; turbo-decoding message passing (TDMP); stream processor; graphical processing units (GPU)