1,486 research outputs found
Single-Scan Min-Sum Algorithms for Fast Decoding of LDPC Codes
Many implementations for decoding LDPC codes are based on the
(normalized/offset) min-sum algorithm due to its satisfactory performance and
simplicity in operations. Usually, each iteration of the min-sum algorithm
contains two scans, the horizontal scan and the vertical scan. This paper
presents a single-scan version of the min-sum algorithm to speed up the
decoding process. It can also reduce memory usage or wiring because it only
needs the addressing from check nodes to variable nodes while the original
min-sum algorithm requires that addressing plus the addressing from variable
nodes to check nodes. To cut down memory usage or wiring further, another
version of the single-scan min-sum algorithm is presented where the messages of
the algorithm are represented by single bit values instead of using fixed point
ones. The software implementation has shown that the single-scan min-sum
algorithm is more than twice as fast as the original min-sum algorithm.Comment: Accepted by IEEE Information Theory Workshop, Chengdu, China, 200
Decoding of Non-Binary LDPC Codes Using the Information Bottleneck Method
Recently, a novel lookup table based decoding method for binary low-density
parity-check codes has attracted considerable attention. In this approach,
mutual-information maximizing lookup tables replace the conventional operations
of the variable nodes and the check nodes in message passing decoding.
Moreover, the exchanged messages are represented by integers with very small
bit width. A machine learning framework termed the information bottleneck
method is used to design the corresponding lookup tables. In this paper, we
extend this decoding principle from binary to non-binary codes. This is not a
straightforward extension, but requires a more sophisticated lookup table
design to cope with the arithmetic in higher order Galois fields. Provided bit
error rate simulations show that our proposed scheme outperforms the log-max
decoding algorithm and operates close to sum-product decoding.Comment: This paper has been presented at IEEE International Conference on
Communications (ICC'19) in Shangha
Fourier Domain Decoding Algorithm of Non-Binary LDPC codes for Parallel Implementation
For decoding non-binary low-density parity check (LDPC) codes,
logarithm-domain sum-product (Log-SP) algorithms were proposed for reducing
quantization effects of SP algorithm in conjunction with FFT. Since FFT is not
applicable in the logarithm domain, the computations required at check nodes in
the Log-SP algorithms are computationally intensive. What is worth, check nodes
usually have higher degree than variable nodes. As a result, most of the time
for decoding is used for check node computations, which leads to a bottleneck
effect. In this paper, we propose a Log-SP algorithm in the Fourier domain.
With this algorithm, the role of variable nodes and check nodes are switched.
The intensive computations are spread over lower-degree variable nodes, which
can be efficiently calculated in parallel. Furthermore, we develop a fast
calculation method for the estimated bits and syndromes in the Fourier domain.Comment: To appear in IEICE Trans. Fundamentals, vol.E93-A, no.11 November
201
A Simplified Min-Sum Decoding Algorithm for Non-Binary LDPC Codes
Non-binary low-density parity-check codes are robust to various channel
impairments. However, based on the existing decoding algorithms, the decoder
implementations are expensive because of their excessive computational
complexity and memory usage. Based on the combinatorial optimization, we
present an approximation method for the check node processing. The simulation
results demonstrate that our scheme has small performance loss over the
additive white Gaussian noise channel and independent Rayleigh fading channel.
Furthermore, the proposed reduced-complexity realization provides significant
savings on hardware, so it yields a good performance-complexity tradeoff and
can be efficiently implemented.Comment: Partially presented in ICNC 2012, International Conference on
Computing, Networking and Communications. Accepted by IEEE Transactions on
Communication
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