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In wireless networks, designing transmission schemes adapting to time varying channel conditions is key to achieve better spectral efficiency. The design of such schemes for multi-hop wireless networks requires coordination among nodes in the network, which is achieved through feedback between nodes. Spectral efficiency can be improved for such networks by designing transmission schemes with limited...
Cooperative decoding is powerful technique for establishing good quality TV broadcasting. In cooperative decoding, some TV receivers, nodes, are cooperated, each other. These share the received information signal and thus obtain good quality information signal. Incremental-Maximum Ratio Combining (I-MRC) is one of the cooperative decoding methods. In I-MRC, the best condition's node and second one...
In this paper, we present a factor-graph based receiver for zero-padded orthogonal frequency division multiplexing (ZP-OFDM) transmissions over deep water channels with extremely long delay spreads. Due to the geometric structure of deep oceans, the channel delay spread between the direct paths and surface/bottom reflections can be on the order of hundreds of milliseconds, which is usually several...
The vector sensor is proposed to apply to the field of the underwater acoustic communication based on Pattern time delay shift coding scheme. The underwater acoustic communication based on the pattern time delay shift coding communication system is a kind of pulse position modulation (PPM), in which the time delay shift values of the Pattern are used to encode the digital information. The azimuth...
Low-density parity-check (LDPC) codes form an important subclass of error correcting coding techniques, and its implementation has been hot spot of domains such as signal process, magnetic recording or next generation communication for years. This paper proposes a configurable FPGA implementation of Partition-and-Shift LDPC decoder based on Min-Sum algorithm. An MPEG algorithm is introduced to reduce...
The decode-and-forward relaying is studied as two problems of the distributed encoding and decoding. Specifically, in the first problem, the source and the relay employ the same channel encoding, and the objective is to find how to distribute the decoding complexity between the relay and the destination. The objective of the second problem is to distribute the encoding complexity between the source...
Berger-invert codes are coding schemes used to protect communication channels against all asymmetric errors and to decrease power consumption. This paper proposes a method of constructing modified Berger-invert codes that relies on the choice of check parts with the smallest possible total weight and assignment of low-weight check parts to the most numerous subsets of data with the largest Hamming...
Interference in several situations, like multiple access interference (MAI) in dense sensor networks, shows strong but rarely occurring pulses that greatly disturb communication, leading to serious performance degradation in classical decoders based on the Gaussian assumption. We propose to represent this impulsive noise with symmetric α-stable (SαS) distribution, well adapted due to its heavy tailed...
We propose the use of simple full interference cancellation (FIC) and orthogonal frequency-division multiplexing (OFDM) within a two-hop asynchronous cooperative four relay network. This approach can achieve the full available diversity and asymptotically full rate. The four relay nodes are arranged as two groups of two relay nodes with offset transmission scheduling. Therefore, the source can serially...
Next generation wireless networks are likely to include cooperative relaying in their design. The performance of certain cooperation schemes in realistic scenarios should be evaluated by system level simulations (SLS). Moreover, the link adaptation (LA) and radio resource management become more complex, since cooperation schemes involve transmissions on more than one link and joint processing at the...
A new approach to joint source-channel coding is presented in the context of communicating correlated sources over multiple access channels. Similar to the separation architecture, the joint source-channel coding system architecture in this approach is modular, whereby the source encoding and channel decoding operations are decoupled. However, unlike the separation architecture, the same codeword...
Multimedia applications like high definition digital television push the manufacturers to increase available bandwidth mainly in Powerline Communication (PLC) links. Because of this needs in this work a PLC link control is developed to maximize the information rate meanwhile the bit error rate (BER) is maintained under a desired reference limit. The developed control system has a unique variable called...
Pre-/post-processing filters obtained from lapped transforms achieve higher coding efficiency by exploiting transform block boundary correlation. Existing approaches however do not explicitly consider the impact of pre-filtering on prediction efficiency, thereby resulting in a lower overall rate-distortion performance. We present a framework where filters are designed with an objective function based...
In this paper we have presented a novel idea to optimize the performance of Low Density Parity Check (LDPC) Codes by using selective encoding and decoding approach. We have also proposed a new simplified form of parity check matrix, h named as beacon matrix which is useful for the efficient implementation of the proposed scheme. The proposed scheme is more suitable for real time applications like...
In this paper we present Low Density Parity Check decoding algorithm that assemble two different algorithms: Sum-Product and Bit-Flipping; we denote Bit Flipping-Sum Product Algorithm (BFSP). To reduce the bit error rate, we perform the Bit-Flipping algorithm after the Sum-Product algorithm. Simulation results over an additive white Gaussian channel show that the error performance of a LDPC codes...
This paper presents some results on MMSE turbo equalization applied to real sea water trials in the Atlantic ocean. High order modulations (8-PSK, 16-QAM and 32-QAM) have been tested. The channel data rate on the underwater acoustic channel is up to 20 kbps. The receiver includes timing recovery, equalization, interleaving and channel coding. The results which are evaluated in term of bit error rate...
In this paper an encoder/decoder pair with memory is designed for fault detection (FD) over networks. The basic idea is to estimate the support of the difference between the process measurement and the estimated one. Then by applying quantization with a uniform quantizer a symbol representing the quantization cell is transmitted. Firstly the channel without packet loss and bit errors is considered...
We investigate the design of Luby Transform (LT) codes with minimum-shift-keying (MSK) modulation over additive white Gaussian noise (AWGN) channels. Both systematic and nonsystematic LT codes are considered from the perspectives of decoding threshold and bit error rate. Using systematic LT codes, coding complexity can be reduced by eliminating the need for decoder-doping, and less parity bits are...
A reduced-complexity modified decoding algorithm for turbo trellis-coded modulation (TTCM) is proposed and evaluated in terms of complexity and bit error rate (BER) performance in an additive white Gaussian noise (AWGN) channel. A novel method is derived from the Chebyshev inequality. In this approach, the max* operation is performed on n≥2 arguments, thus the recursive calculations are avoided and...
3GPP LTE requires a 100 Mbps of peak bandwidth, and the instantaneous throughput demand changes with different applications. Fixed sub-block parallel turbo decoding scheme introduces bit-error rate (BER) performance drop when the block length is short. In this paper, an LTE turbo decoder implemented on a 0.66 mm2 die in a 65 nm CMOS technology is presented. An adaptive sub-block parallel (ASP) decoding...
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