2,640 research outputs found
A Randomized Construction of Polar Subcodes
A method for construction of polar subcodes is presented, which aims on
minimization of the number of low-weight codewords in the obtained codes, as
well as on improved performance under list or sequential decoding. Simulation
results are provided, which show that the obtained codes outperform LDPC and
turbo codes.Comment: Accepted to ISIT 2017 Formatting change
Polar Codes with Dynamic Frozen Symbols and Their Decoding by Directed Search
A novel construction of polar codes with dynamic frozen symbols is proposed.
The proposed codes are subcodes of extended BCH codes, which ensure
sufficiently high minimum distance. Furthermore, a decoding algorithm is
proposed, which employs estimates of the not-yet-processed bit channel error
probabilities to perform directed search in code tree, reducing thus the total
number of iterations.Comment: Accepted to ITW201
Successive Cancellation Ordered Search Decoding of Modified -Coset Codes
A tree search algorithm called successive cancellation ordered search (SCOS)
is proposed for -coset codes that implements
maximum-likelihood (ML) decoding with an adaptive complexity for transmission
over binary-input AWGN channels. Unlike bit-flip decoders, no outer code is
needed to terminate decoding; therefore, SCOS also applies to
-coset codes modified with dynamic frozen bits. The average
complexity is close to that of successive cancellation (SC) decoding at
practical frame error rates (FERs) for codes with wide ranges of rate and
lengths up to bits, which perform within dB or less from the
random coding union bound and outperform Reed--Muller codes under ML decoding
by up to dB. Simulations illustrate simultaneous gains for SCOS over
SC-Fano, SC stack (SCS) and SC list (SCL) decoding in FER and the average
complexity at various SNR regimes. SCOS is further extended by forcing it to
look for candidates satisfying a threshold on the likelihood, thereby
outperforming basic SCOS under complexity constraints. The modified SCOS
enables strong error-detection capability without the need for an outer code.
In particular, the PAC code under modified SCOS provides gains in
overall and undetected FER compared to CRC-aided polar codes under SCL/dynamic
SC flip decoding at high SNR.Comment: 14 pages, 9 figures, 3 tables. Submitted to IEEE journal. The revised
version of the first submission. Major changes: 1) No dedicated section for
numerical results. Instead, simulations are provided right after the relevant
section. 2) More simulation results are added to compare all the state of art
polar decoders in terms of the number of arithmetic operations. arXiv admin
note: text overlap with arXiv:2105.0404
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