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In this paper, we investigate the performance and the design of Joint Source-Channel Decoding (JSCD) schemes involving structured Low-Density Parity-Check (LDPC) codes such as protograph based codes. We first present the asymptotic analysis of such iterative receivers based on multi-dimensional EXIT charts. Since a protograph can be interpreted as different encoding schemes, the information mapping...
Coordinated multi-point processing at multiple base stations can improve coverage and throughput for future cellular systems. In this paper, we study the coordinated reception at multiple MIMO base stations by proposing cooperative multi-cell automatic repeat request (ARQ) protocols via wired backhaul links. In particular, we consider three protocols where the cooperative base stations employ different...
Base station cooperation is a promising solution to the interference limitation of today's cellular networks. The capacity and fairness gains shown by information theoretical analysis of base station cooperation in cellular networks are huge. However, a major downside is the information exchange among base stations, which is the motivation for recent work on backhaul efficient cooperation schemes...
We propose two practical schemes for the cancellation of nonlinear distortions caused by the power amplifiers (PA) in Orthogonal Frequency Division Multiplexing (OFDM) systems. The algorithms are iterative and located at the receiver. They utilize a soft channel decoder to improve the capabilities of the distortion estimation and relay all the computational complexity to the receiver. Simulation results...
The QR Decomposition (QRD) of communication channel matrices is a fundamental prerequisite to several detection schemes in Multiple-Input Multiple-Output (MIMO) communication systems. Herein, the main feature of the QRD is to transform the non-causal system into a causal system, where consequently efficient detection algorithms based on the Successive Interference Cancellation (SIC) or Sphere Decoder...
Bit-interleaved coded modulation with iterative decoding (BICM-ID) performs well under a variety of channel conditions. Based on a factor graph representation of BICM-ID, we propose a modification of the BICM-ID receiver that can reduce the computational complexity significantly without BER degredation. The basic idea is to avoid updates of code bit log-likelihood ratios whose magnitude is already...
The problem of affine transform attacks refers to many watermarking algorithms. A slight change in the geometry of watermarked image can disable the decoding of embedded information; therefore the advanced watermarking methods should be robust against the above-mentioned procedures. This paper contains a description of the algorithm consisting of two complementary methods of image watermarking. The...
The article describes a new method of embedding and extracting the digital watermark in an acoustic signal, which operates in the frequency domain and uses a drift correction modulator of the watermark's phase angle, as well as a precise correction procedure of the watermark signal to the minimum masking threshold. This method does not require synchronization reproduction at the receiving side in...
In this paper, we present a class of LT codes with a novel degree distribution that is distinct from the degree distribution previously described by Luby. We show that with high probability the total size of the packets needed for decoding of these new LT codes is close to the original size of the file. Furthermore, the encoding and decoding complexity of LT codes with this new degree distribution...
An encryption method based on turbo code is proposed in this paper. In the scheme, we adopt an improved interleaver for turbo code. The new interleaver has two characteristics: (a) It provides low correlation for information bits in one turbo frame, which means better error correction capability for short turbo code; (b) The output of the interleaver is controlled by the secret key, therefore the...
The maximum likelihood (ML) detection is the optimal detection method for multiple-input multiple-output (MIMO) communication systems. The normal K-best sphere decoding algorithm (SDA) can guarantee a fixed throughput, but it induces a large bit error rate (BER) degradation. In order to achieve close-to-ML performance, the K value needs to be sufficiently large. Thus, it needs large computation with...
In this paper, we propose the design method and the structure of a decoder with shortened cyclic code for radio data systems (RDS). Without microprocessor the logic gates are used to implement the hardware of the decoder, moreover, the decoder not only can decode the received message of RDS, but also has the functions of synchronization, error detection and error correction. The proposed decoder includes...
Trapping sets (TSs) have been known to contribute to errors in the decoding of low-density parity-check (LDPC) codes, particularly at the high signal-to-noise ratio (SNR) region. Moreover, TSs with the same label [w; u] are considered equivalent under the automorphism of the graph of a regular code. But according to our our simulations, TSs with the same label [w; u] are producing different error...
In this paper, a very high-throughput and area efficient hardware decoder of the binary (23, 12, 7) Golay code is presented. The key feature of this proposed algorithm is fast determination of the error positions through the analysis on the weight of syndromes without large operations of finite fields. Comparing with the algorithm using one syndrome, the proposed algorithm is more suitable for the...
A simple soft-demapping scheme for rectangular quadrature amplitude modulation (R-QAM) signals is developed for a low-cost 60 GHz OFDM baseband chip design, conforming to the IEEE802.15.3C standard. The scheme is equally applicable to a generic bit-interleaved orthogonal frequency division multiplexing (OFDM) modulation for both square QAM (S-QAM) and R-QAM constellations. The channel coding employs...
In digital mobile communication systems, speech coding is very important to increase the bandwidth efficiency. Usually, speech coding algorithms determine speech parameters, which are highly sensitive to transmission errors. In this paper, we use the residual redundancy remaining after using the Enhanced Variable Rate Codec (EVRC) algorithm for error concealment. Average residual redundancies of the...
The need for watermarking database relations to deter their piracy, identify the unique characteristics of relational data which pose new challenges for watermarking, and provide desirable properties of a watermarking system for relational data. Proving ownership rights on outsourced relational databases is a crucial issue in today's Internet-based application environments and in many content distribution...
This paper presents an efficient fuzzy possibilistic code book design for vector quantization in the wavelet packet domain. Wavelet packet tree (WPT) methodology is applied to the whole image. The sub blocks of the input image are decomposed into two level WPT where all coefficients of LL band and the approximation coefficients of LH, HL & HH bands are quantized using the proposed vector quantizer...
In this paper we present a new method for designing of decoder in quantum computing based on field effect in nuclear spin. We use nuclear property of hydrogen in order to logical truth value. Computational results demonstrator the accuracy and efficiency, that can be obtained with the use of these models, are presented.
An iterative source-channel decoding scheme which exploits the source residual redundancies on symbol-basis is proposed. We first derive a modified BCJR algorithm based on the sectionalized code trellis for symbol decoding of the convolutional codes. This is used in conjunction with a softbit source decoder that computes the interpolative a posteriori probabilities of quantizer indexes. Simulation...
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