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Highly reliable data compression technique. Flash Reliability Boost Huffman coding (FRBH) is proposed for TLC NAND Flash memory. By decreasing the write data size and optimizing the memory cell Vth distribution at the same time, FRBH decreases data-retention errors by 92% and increases data-retention time by over 2900 times.
We introduce a model of a combination of particular low density parity check (LDPC) code and quadrature-quadrature phase shift keying (Q2PSK) constellation for the application of the downlink of the unmanned aerial vehicle (UAV) data chain. This model is a modification of the combination of LDPC code and constant envelope Q2PSK (CEQ2PSK) constellation. It achieves higher bandwidth efficiency of 4/3...
This work studies the performance of a cooperative network which consists of two channel-coded sources, multiple relays, and one destination. Due to the spectral efficiency constraint, we assume that a single time slot is dedicated to relaying. Conventional network-coded based cooperation (NCC) selects the best relay which uses network coding to serve the two sources simultaneously. It is shown that...
This paper presents an improvement to the end-to-end bit error rate (E2E-BER) performance of turbo-coded orthogonal frequency division multiplexing for physical layer network coding (TC-OFDM-PLNC) over power line communication (PLC) channels in the presence of impulsive noise. A novel detection scheme is introduced to transform the transmit signal constellation based on the frequency-domain channel...
In this letter, a new early termination method is proposed for Luby transform (LT) belief propagation (BP) decoder. The proposed method is decided whether BP decoder output converges to original data bits by observing only sign alterations of log-likelihood ratio (LLR) messages in BP decoder structure. Simulation results and complexity analyzes show that proposed method has low computational complexity...
In harsh channel conditions, the quality of the synthetic speech at low bit rate would be affected severely. In order to improve the robustness of the vocoder and make it more resilient to errors in random channel, unequal error protection (UEP) channel coding is usually adopted. However, when the errors cannot be corrected in some cases, UEP channel coding will not improve the quality of the synthetic...
Cross-entropy (CE) based stopping criteria is known for its early termination capability of the turbo decoding iterations without scarifying its performance, in terms of bit error rate (BER). This advantage, however, performs well in high signal-to-noise ratio (SNR) albeit requiring infinite iterations at low SNR, thereby resulting in more unwanted computations and decoding delays. In this paper,...
This paper investigates the problem of recovering an n-dimensional BPSK signal x0 ∈ {−1, 1}n from m-dimensional measurement vector y = Ax+z, where A and z are assumed to be Gaussian with iid entries. We consider two variants of decoders based on the regularized least squares followed by hard-thresholding: the case where the convex relaxation is from {−1, 1}n to ℝn and the box constrained case where...
NAND flash memory has decreasing storage reliability, as the density or program/erase (P/E) cycle increases. To ensure data integrity, error correction codes (ECCs) are widely employed and typically stored in the out-of-band area (OOB) of flash pages. However, the worst-case oriented ECC is largely under-utilized in the early stage (small P/E cycles), and the required ECC redundancy may be too large...
In this paper, we propose a new setup for a cooperative multi-relay non-orthogonal multiple access scheme (CMR-NOMA) to enhance the downlink performance of non-orthogonal multiple access, while operating in severe fading. We compare the performance of the proposed scheme to an existing cooperative non-orthogonal multiple access scheme (CNOMA) in terms of the user-average bit error rate, the ergodic...
Gradient descent bit-flipping (GDBF) algorithm achieves good error performance for decoding low density parity check codes. In the GDBF algorithm, a search point is apt to be trapped in a local optimum, which causes performance degradation of the GDBF algorithm. To overcome this issue, the noisy GDBF algorithm introduces random perturbation into the inversion function of each symbol, which decreases...
There are many research on hybrid selective-repeat ARQ method. In many previous research purposes have been to maximize a throughput on the number of messages delivered to the user. Important theoretical limits were studied under the condition that a decoding error was very small and neglected. In this research we propose the optimal type-I hybrid selective-repeat ARQ with finite receiver buffer....
Braided convolutional codes (BCCs) are a class of spatially coupled turbo-like codes (SC-TCs) with excellent belief propagation (BP) thresholds. In this paper we analyze the performance of BCCs in the finite block-length regime. We derive the average weight enumerator function (WEF) and compute the union bound on the performance for the uncoupled BCC ensemble. Our results suggest that the union bound...
In this paper we propose a generalized concatenated code (GC code) construction based on shortened Reed-Solomon inner codes and nonbinary LDPC outer codes. We also propose a soft-input decoder for this construction that makes use of soft-input soft-output decoding of both inner and outer codes. We show that this construction gives significant coding gain. We also compared it to generalized error-location...
Product codes are a concatenated error-correction scheme that has been often considered for applications requiring very low bit-error rates, which demand that the error floor be decreased as much as possible. In this work, we consider product codes constructed from polynomial algebraic codes, and propose a novel low-complexity post-processing technique that is able to improve the error-correction...
Most of the turbo decoding stopping criteria assume perfect channel reliability available at the receiver since they require a threshold based on signal-to-noise ratio (SNR) information. However, operational environments can vary according to frame sizes, code structures and channel reliability requirements, further aggravating the difficulty in threshold determination and convergence or non-convergence...
Filter bank multi-carrier with offset quadrature amplitude modulation (FBMC/OQAM) is considered as a promising alternative to orthogonal frequency division multiplexing with the cyclic prefix insertion (CP-OFDM). In this paper, a MIMO-FBMC using turbo code is proposed and a comparison is made between turbo coded MIMO-OFDM and turbo coded MIMO-FBMC systems. The evaluation of bit error rate and signal-to-interference...
In this paper, the performance of iterative turbo coding with nonlinearly distorted orthogonal frequency division multiplexing (OFDM) signal is analyzed. System level implementation in Simulink is performed and bit error rate (BER) performance is analyzed. Initially, we have implemented both, the series turbo coder and iterative turbo coder, compared the performance and then using better performed...
Multicolored Matrix (MCM) Code is a two-dimensional color coded matrix. It consists a sequence of images rendered at an optimum frame rate to transfer simple data between portable devices such as a mobile phone. We introduce an untried channel-less short range communication technology, designed with limitless storage capacity, great structural stability and flexibility due to which it can work in...
The Multidimensional Parity Check codes (MDPC) are one of the possible FEC methods of the short information messages. Especially the MDPCs with reduced generator matrix results in codes with block length from few to tens of bits with indispensable code-gain. This paper presents two methods of generation of the MDPC and describe the algorithm for iterative decoding of these codes. The MDPC with short...
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