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Layered Decoding Algorithm and Two-Level Quasi-Cyclic Matrix Construction for Rate Compatible Modulation.
- Source :
-
IEEE Transactions on Circuits & Systems. Part I: Regular Papers . Aug2019, Vol. 66 Issue 8, p3213-3226. 14p. - Publication Year :
- 2019
-
Abstract
- Rate-compatible modulation (RCM) achieves seamless rate adaptation under time-varying channels by varying the number of transmitted symbols at a small granularity. The implementation of effective decoders based on the belief propagation (BP) algorithm suffers from the varying number of symbols and highly complex symbol nodes. Considering these RCM-specific characteristics, we present a top–down design methodology, including decoding algorithm, mapping matrix construction, and hardware implementation. The layered BP algorithm provides the potential to implement the decoders that fine-tune the decoding throughput according to the number of symbols. To mitigate the impact of inter-layer data dependency on decoding throughput and facilitate the implementation of low parallelism decoders, a construction and optimization algorithm is proposed to obtain the two-level quasi-cyclic matrices with small sub-matrix size. The proposed algorithm and matrix are applied to a partially parallel RCM decoder for a ${5544 \times 5544}$ matrix on a field-programmable gate-array (FPGA) device. A memory access structure that requires only one barrel shifter is used to improve area efficiency. The post-route results show that the decoder achieves a throughput of 377 M ~ 1100 Mbit/s at six iterations with a clock frequency of 218 MHz. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 15498328
- Volume :
- 66
- Issue :
- 8
- Database :
- Academic Search Index
- Journal :
- IEEE Transactions on Circuits & Systems. Part I: Regular Papers
- Publication Type :
- Periodical
- Accession number :
- 137378100
- Full Text :
- https://doi.org/10.1109/TCSI.2019.2906774