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Most recently, the low density parity check codes are chosen as the channel encoding method to encode the Wyner-Ziv frames in distributed video coding. These codes involve much complicated encoding and decoding algorithms, and might increase the processing time of the system. In this paper, we use the codes with simpler encoding and decoding algorithms, the Reed Solomon codes, and compare the performance...
The L1 signaling part of the DVB-T2 system uses punctured low-density parity check (LDPC) codes. This paper provides some implementation details regarding decoding punctured LDPC codes. The implemented program can successfully decode digitalized DVB-T2 signal from a generator.
We design and assess some practical low-density parity-check (LDPC) coded transmission schemes for the Gaussian broadcast channel with confidential messages (BCC). This channel model is different from the classical wiretap channel model as the unauthorized receiver (Eve) must be able to decode some part of the information. Hence, the reliability and security targets are different from those of the...
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...
Non-orthogonal multiple access improves spectral efficiency through sharing the same frequency resource with multiple wireless terminals. In the previous researches, it has been shown that a log likelihood ratio (LLR) calculated from a signal on the sharing spectrum should be masked to zero if the power of an interference signal is stronger than that of a desired signal. This implies that the spectrum...
In this paper, we present a practical Dirty Paper Coding (DPC) scheme using sum codes based on LDPC codes. While a typical sum-code-based DPC scheme uses a constrained decoder as part of the encoding operation, such an approach fails in the case of LDPC codes since the constrained decoder based on a standard LDPC decoder tends to get stuck at highly suboptimal points in typical scenarios. We get around...
In most communication systems, being able to adapt the error protection strength of the physical layer is essential to ensure the functionality of the system in potentially strongly varying conditions. Traditional forward error correction code design focuses on the optimization of codes with a fixed code rate for a worst-case channel condition. So-called rate-compatible codes, on the other hand, are...
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.
This paper presents a novel encoding algorithm for QC-LDPC codes constructed from Reed-Solomon codes. The encoding is performed in the transform domain via Galois Fourier transformation. Message bits are encoded in sections corresponding to sub-matrices of the parity-check matrix in the transform domain. Because of the structure of the parity-check matrices of these LDPC codes, the encoding can be...
This paper proposes two approaches that reduce the complexity of the Polar Coding Steganography (PCS). The first is based on lookup tables and the second exploits the form of the syndrome, calculated from cover vector and secret message, to evaluate la position of the cover vector changes. The scheme proposed in this paper allows minimizing the embedding impact and gives similar results as those of...
In this paper, generalized pseudo-cyclic (GPC) codes are proposed and their basic properties are investigated. Generator polynomial matrices of GPC codes are constructively defined and thereby a dimension formula for GPC codes is provided. While a pseudo-cyclic code is equal to an ideal of the ring which consists of polynomials modulo a fixed polynomial, a GPC code is equal to a submodule of the direct...
Raptor codes are the first class of fountain codes with linear time encoding and decoding. These codes are recommended in standards such as Third Generation Partnership Project (3GPP) and digital video broadcasting. RaptorQ codes are an extension to Raptor codes, having better coding efficiency and flexibility. Standard Raptor and RaptorQ codes are systematic with equal error protection of the data...
Recently a variety of lattices called low density lattices codes (LDLC) have been studied because they can be decoded efficiently using belief propagation, and can be seen as a Euclidean space codes analogue to low density parity check codes (LDPC). Previous LDLC lattice designs, like Latin square, are based on high-complexity computer search to eliminate 4-cycles. Array codes have been used to construct...
Mobile devices have multiple network interfaces, some of which have security weaknesses, yet are used for sensitive data despite the risk of eavesdropping. We describe a data-splitting approach which, by design, maps exactly to a wiretap channel, thereby offering information theoretic security. Being based on the deletion channel, it perfectly hides block boundaries from the eavesdropper, which enhances...
A class of GLDPC-codes is proposed consisting of multiple local-codes suitable for code-rate-adaptation in high-speed optical-transport-networks, providing excellent coding-gains. GLDPC-decoder for this class of codes is more suitable for parallelization in FPGA/ASIC-hardware compared to LDPC-decoder.
We propose a class of rate-compatible (RC) low-density parity-check (LDPC) codes that has linear encoding complexity and low error floor. To ensure linear encoding, a deterministic form for the parity part of the mother parity-check matrix is used. To guarantee good performances in the waterfall region for a wide range of code rates, a layered density evolution algorithm is developed to obtain the...
In this paper we investigate several central aspects of using the unslotted Contention Resolution Diversity ALOHA (CRA) scheme with Successive Interference Cancellation (SIC). A model for the co-user-interference under consideration of time-, phase- and frequency-offsets is presented. With this model, the throughput and Packet Loss Ratio (PLR) performance of CRA is investigated when using Low Density...
Error-correction coding techniques have been used to exploit imperfections in the physical layer of the communications protocol stack to obtain both reliability and security without the need for secret keys. In a multi-hop network, however, colluding eavesdropping nodes can share information to effectively reduce errors in the eavesdropping channels and, hence, overcome the secrecy offered through...
The design of multi-Gbps LDPC decoder has become a hot topic in recent years as the demand of the transformation towards 4G. In this paper, we describe an energy efficient multi-Gbps LDPC decoder engine based on ASIP using Target tool suite. The ASIP core can be configured as half-layer paralleled or quarter-layer paralleled decoding, which offers a good trade-off between the throughput and power/area...
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,...
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