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A low-density parity-check (LDPC) code of column weight of 2 is known as an LDPC cycle code. In this paper, we study the encoding algorithm about a type of non-binary quasi-cyclic LDPC cycle codes. The position of parity check symbols is located firstly through parity check equations. Then, we show that these parity check symbols can be calculated linearly through the corresponding Tanner graph. It...
Multimedia security can be foiled thanks to Slepian's permutation modulation. Originally proposed in 1965 for standard problems of channel and source coding in communications, permutation codes can also provide optimum solutions in two relevant fields: steganography (foiling hidden information detection tests) and counterforensics (foiling forensic detection tests). In the first scenario, permutation...
In emerging 3D video coding, depth has significant importance in view synthesis, scene analysis, and 3D object reconstruction. Depth images can be characterized by sharp edges and smooth large regions. Most of the existing depth coding techniques use intra-coding mode and try to preserve edges explicitly with approximated edge modelling. However, edges can be implicitly preserved as long as the transformation...
Fountain codes are gradually being incorporated into broadcast technologies, such as multimedia streaming for 4G mobile communications. In this paper, we investigate the capability of existing fountain-coded schemes to recover a fraction of the source data at an early stage and progressively retrieve the remaining source packets as additional coded packets arrive. To this end, we propose a practical...
Nowadays, a huge number of WiFi devices are distributed in anywhere place. Because tremendous WLAN devices are transmitting in ISM bands, the interference problem has emerged as an important issue. The simple method to solve the interference problem is to avoid to the other vacant operating channel. However, current ISM band might be already shortage because of operating many WiFi devices. So, the...
In this paper we propose a modification of double error correcting (DEC) BCH codes that allows for a fast correction of arbitrary 1-bit and 2-bit errors, as well as 3-bit errors comprising adjacent 2-bit errors in certain bit positions. The proposed code has the same number of check bits as a double error correcting, triple error detecting (DEC-TED) BCH code with code distance 6. The proposed code...
Matrix Quantization (MQ), a very promising source coding technique, has already been successfully applied for speech signals and noiseless channels. MQ is also shown in the literature to outperform Vector Quantization (VQ) when applied over noisy channels. Considering that most sources of practical interest are non-stationary, this paper introduces a technique which adapts MQ to varying source statistics...
An analysis of previously derived Ambisonics decoders shows that the mid-high frequency performance of these decoders has poor agreement with subjective perception, since the optimized decoder coefficients could not well meet the objectives developed by the energy vector, and the polar pattern of speaker feeds is suboptimal. In this paper, new objectives are added to fitness function for the optimal...
We present algorithms for initializing networks that use a convolutional network coding scheme and that may contain cycles. During the initialization process every source node transmits basis vectors and every sink node measures the impulse response of the network. The impulse response is then used to find a relation between the transmitted and the received symbols, which is needed for a decoding...
With random linear network coding, mixed packets contain in their headers information about the coding operations performed on the original packets to allow their recovery by the receiver. This introduces an overhead that could be significant if the packet size is relatively small w.r.t. the size of the generation. In this paper, we propose to remove the part of the added header related to the network...
Reliability has become one of the most vital requirements in wireless sensor networks (WSNs). One efficient way to increase the reliability is by using erasure coding techniques such as Reed-Solomon/Cauchy Reed-Solomon. The problem is the time required for encoding and decoding the data words, especially when large amount of data need to be sent like in complex WSN applications. In this paper, we...
The recently proposed single block-row quasi-cyclic low-density parity-check (QC-LDPC) codes are favorable for high-speed applications. However, conventional decoder design methods are not suitable for this kind of codes. To tackle this issue, this paper aims at designing efficient column-layered single block-row QC-LDPC decoder architecture without affecting the decoding performance. Moreover, the...
As an extension of binary low-density parity-check (LDPC) codes, non-binary LDPC (NB-LDPC) codes show significantly better performance when the code length is moderate or small. Recently, enhanced iterative hard reliability based (EIHRB) decoding algorithm is proposed to reduce the computation complexity. However, the EIHRB algorithm suffers a lot from significant performance degradation when the...
In this paper, we study iterative detection algorithms of the multi-cell multi-user massive MIMO systems with pilot contamination. First, a iterative algorithm applying soft decision interference cancellation is introduced. It is based on minimum mean square error (MMSE) filter and derived from [1] where it was applied in block transmission. Then, by considering the algorithm complexity, two iterative...
A novel cloud transmission (CTxn) technique is proposed on the basis of the multiple-input multiple-output (MIMO) technique, called MIMO CTxn. Applying a MIMO technique to conventional SISO CTxn provides a very efficient way to support high-date-rate service for delivering local content, even for a negative SINR. Simulation results show that the performance of MIMO CTxn is better than that of SISO...
This paper proposes a hybrid message-passing decoding algorithm which consumes very low computational complexity, while achieving competitive error performance compared with conventional min-max algorithm. Simulation result on a (255,175) cyclic code shows that this algorithm obtains at least 0.5dB coding gain over other state-of-the-art low-complexity non-binary LDPC (NB-LDPC) decoding algorithms...
We present a new efficient algorithm for the search version of the approximate Closest Vector Problem with Preprocessing (CVPP). Our algorithm achieves an approximation factor of O(n/sqrt{log n}), improving on the previous best of O(n^{1.5}) due to Lag arias, Lenstra, and Schnorr {hkzbabai}. We also show, somewhat surprisingly, that only O(n) vectors of preprocessing advice are sufficient to solve...
We consider a multiuser scenario with a center node for data fusion, where simultaneously transmitting is required in real time and with low probability of interception. We established a novel multiple access scheme, named matrix division multiple access (MDMA), based on OFDM technology. Precoded with different matrices, the signal from different end nodes can be distinguished due to the signal space...
Motivated by code design for real-time simultaneous information and energy transfer, we characterize achievable rates and error exponents for discrete memoryless channels using constant subblock composition codes (CSCCs). All subblocks within every codeword in a CSCC have the same fixed composition. For a given channel, this composition may be chosen to balance the tradeoff of receiving high information...
Distributed storage systems have been receiving increasing attention lately due to the developments in cloud and grid computing. Furthermore, a major part of the stored information comprises of multimedia, whose content can be communicated even with a lossy (non-perfect) reconstruction. In this context, Multiple Description Lattice Quantizers (MDLQ) can be employed to encode such sources for distributed...
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