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The performance of Polar codes has been proved to achieve the Shannon capacity when N, the block length, tends to infinity. However, finite block length performance of Polar codes is rather poor compared to other capacity approaching codes such as LDPC (Low-Density Parity-Check) codes. In this paper, we propose a concatenated scheme with a polar code as an inner code and a Reed-Solomon code as an...
Random Linear Network Coding (RLNC) provides a theoretically efficient method for coding. The drawbacks associated with it are the complexity of the decoding and the overhead resulting from the coding vector. This adds to the overall energy consumption and is problematic for computational limited and battery driven platforms. In this work we present an approach to RLNC where the code is sparse and...
Wireless broadcast has been widely utilized to deliver information of common interest to a large number of users. A major challenge for wireless broadcast is that wireless links are often unreliable. Further, it is not feasible for every receiver to acknowledge the correct reception of broadcasted packets. In this paper we investigate the use of wireless broadcast to deliver a given number of packets...
Low Density Parity Check (LDPC) Codes offer remarkable error correction performance and therefore increase the design space for communication systems. When implementation complexity and latency are not system limitations, LDPC codes can offer near Shannon Limit performance by using large code lengths and increasing the number of iterations in the decoding process. Furthermore, LDPC codes with smaller...
In this paper, we propose a simplified belief propagation(SBP) decoder for the polar codes, where the update calculation for the messages of the so-called frozen nodes is replaced by setting these nodes' messages by prior probabilities during the BP procedure. Numerical results show that the derived SBP yields almost the same performance as the BP decoders in the literature, while the computational...
This paper deals with the application of Spatial and Temporal DWT (Discrete Wavelet transform) on the videos. Here we will discuss about three mechanisms and their performance on videos at increased DWT level. In any video processing algorithm, memory is the major criteria. In these three mechanisms dynamic (automatic) DWT level selection and manual level selection is implemented. Here we will also...
LDPC codes can be constructed by tiling permutation matrices that belong to the square root of identity type and similar algebraic structures. We investigate into the properties of such codes. We also present code structures that are amenable for efficient encoding.
Large-scale distributed storage systems are prone to node failures. To provide fault tolerance, data is often encoded to maintain data redundancy over multiple storage nodes. If a node fails, it can be repaired by downloading data from surviving nodes and regenerating the lost data in a new node. Network coding has recently been proposed (e.g., see [2]) to generate data redundancy. It is shown that...
Layered decoding is well appreciated in Low-Density Parity-Check (LDPC) decoder implementation since it provides efficient and high-throughput implementation of LDPC decoders. Variable-Node Layered Belief Propagation (VL-BP) algorithm and their reduced-complexity derivatives for LDPC codes are presented. The VL-BP algorithm is a modification of Belief Propagation algorithm (BP), where the variable...
Bit-cooperative coded modulation (BCCM), known as an improved bit-interleaved coded modulation (BICM) scheme [1], introduces known bits to jointly design the channel coding and modulation. In this paper, we contribute to the theoretical analysis of the turbo-coded BCCM scheme, and specifically, the impact of the known bits on the turbo decoding process. The characteristic of the iteration process...
With the rapid growth of data and the growing demand from users on the system performance, data availability has become the most important issue in large-scale storage systems. Due to the ability to provide space-optimal data redundancy to protect against node failures, erasure codes have seen widely deployment. To ensure data availability, it is crucial to recover node failures quickly. In this paper,...
In this paper, we propose reliability adjustment weighted bit-flipping (RA-WBF) decoding algorithm for low density parity-check (LDPC) codes. By adjusting the reliability of received symbols during iterative decoding, the proposed algorithm can offer better tradeoff between performance, convergence speed and computational complexity. Furthermore, this improvement can easily be extended to other variations...
Distributed video coding (DVC) is a compression method that aims to produce low complexity encoding. One of the main practical problems facing DVC is that the encoder must know the required rate. Theoretically, the rate is lower bounded by the conditional entropy of the source given the side information. In practice, there are losses that must also be taken into account in estimating the rate. However,...
Structured prediction has wide applications in many areas. Powerful and popular models for structured prediction have been developed. Despite the successes, they suffer from some known problems: (i) Hidden Markov models are generative models which suffer from the mismatch problem. Also it is difficult to incorporate overlapping, non-independent features into a hidden Markov model explicitly. (ii)...
The traditional framework under which error-correcting codes can enable secrecy involves the use of nested codes. While this structure provide us with means to achieve weak secrecy, it is not clear how these codes can be applied to varying wiretap channels. In the spirit of rate-compatible codes, we propose a new framework for coding for the wiretap channel. The proposed scheme is based on random-puncturing,...
Check node update processing for non-binary LDPC (NB-LDPC) architectures requires a large number of clock cycles, which limits the achievable throughput to tens of Mbps for high rate codes. In this work, we propose a new NB-LDPC architecture based on the Trellis-EMS (T-EMS) algorithm that reduces the number of clock cycles by a factor of dc, by adding an extra column to the trellis. This feature makes...
It is very important to reduce the energy consumption of low-density parity-check (LDPC) decoders, especially for the intelligent and mobile terminals in green communications. This paper presents a novel energy-efficient layered decoder (EELD) to save the power consumption of quasi-cyclic LDPC (QC-LDPC) decoders based on the layered belief propagation (LBP) algorithm. The EELD forces a check-node...
In this paper, we propose two low-complexity decoding algorithms for systematic binary deterministic rateless codes. One is based on segmentation available for large information block. Segmentation-based decoding algorithm can dramatically reduce the complexity on solving inverse of matrix, which dominates the complexity of decoding. Another is based on enumeration for small information block. Enumeration-based...
For the space application, error detection and correction (EDAC) technique is often adopted to protect memory cells against Single Event Upset (SEU) errors. To improve the EDAC ability and in view of the parity memory having 8 bits width, a single error correction and double error detection (SEC-DED) (40,32) Hamming code is proposed. This scheme is on the base of (39,32) Hsiao code, adding a check...
In this paper, soft-input/soft-output decoding of an arbitrary linear block error correction code over any finite field is performed by transforming an algebraic description of the decoding problem to a binary message passing decoding problem, such as used for a binary LDPC decoder. Field symbols are represented using a Hadamard-like transform of the probability distribution over the field, and field...
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