Remnant error concealment technique for error recovery

In this paper, the error concealment techniques as motion vector extrapolation (MVE), boundary matching (BM), side matching (SM), 16/spl times/16-MB-based and 8/spl times/8-block-based concealment are implemented and compared with feedback-based no waiting ARQ (NWARQ) error recovery technique. A new error concealment method using preprocessing (PREP) and search is proposed and implemented. This new method tries to use the information of surrounding MV as much as possible, and find a more precise motion vector using additional search processing in a search window centered by the estimated motion vector. Simulation results, based JM1.4 codec of JVT, show that both NWARQ and PREP can significantly improve the reconstruction video quality. And the combined PREP, SEARCH and NWARQ techniques can greatly achieve improved performance. From the simulation results, the SM and 16/spl times/16-MB-based concealment methods show better performance than BM and 8/spl times/8-block-based concealment.

Modeling and design of single ring core DC sensor based on a new readout method for DC power system protection

In this paper a hybrid error concealment algorithm using linear interpolation is proposed. In the proposed hybrid algorithm, the selective motion field interpolation (SMFI) is employed to conceal the erroneous macroblock. The spatial and temporal boundary-matched errors are then used to check whether the SMFI conceals the erroneous macroblock properly. If the temporally recovered macroblock is reconstructed incorrectly, the spatial error concealment using linear interpolation is employed to conceal the damaged macroblock instead of SMFI.It can achieve better performance subjectively as well as objectively over other error concealment techniques such as AMV, FBBM and MFI. Simulation was conducted on the H.263 codec and the experimental results reveal that the proposed algorithm significantly outperforms other concealment techniques.

In this research work, we have developed a communication system (transmitter / receiver) to control peak to average power (PAPR) with small bit error rate (BER) for a 4G system called multicode code division multiple access (MCCDMA). Proposed communication system works on modified Reed Muller encoded data (MRMED) string. In MRMED data is first encoded with Reed Muller (RM) code. Thereafter, encoded RM message is XORed with optimal binary string, which results lower Peak to Average Power ratio (PAPR). A well-known fact is that, bit error rate (BER) is the best performance measurement tool for a communication system. To check the integrity of our communication system, we have run the simulation for monitoring BER using MRMED sequence. Simulation work conducted, with multipath Rayleigh fading, Minimum Shift Keying (MSK) modulation and several orders of RM codes. Our results show that implementing MRMED sequences of the suggested MCCDMA communication structure, returns noticeable lower BER. For instance, in case of RM(1,4), that has error improvement proficiency of 3 (three) errors , returns BER = 8.2x10−5 adopting MSK, at SNR = 12dB. Similarly, for RM(2,3), which has error improvement efficiency of 0 error and shows distinct BER of 4.9x10−4 at 12dB (SNR).In addition to using simulation for checking BER performance of our communication system, we have also shown in our results that, as the error improvement capability of different RM codes surges, correspondingly we get a lower BER.

The three-dimensional video (3DV) is composed of variable-length stream sequences captured via diversified cameras surrounding an object. Thus, it is an urgent task to accomplish sufficient encoding to be compatible with incoming bandwidth demands, while achieving a recommended 3DV reception performance. In the 3DV compression framework, the lost macro-blocks (MBs) might propagate into the following frames and the adjoining views. Therefore, it is obligatory to avoid error propagation by concealing the corrupted MBs at the decoder through the utilization of appropriate post-processing error concealment (EC) techniques. The existing EC algorithms fundamentally exploit the temporal, inter-view, and spatial matching within the 3DV frames and views to reconstruct the disparity vectors (DVs) and motion vectors (MVs) of the corrupted MBs. Unluckily, in the state of high severe corruptions and heavily erroneous MBs, these concealment algorithms are predominantly unreliable and might give unreliable 3DV quality. Thence, in this work, we suggest the utilization of the outer block boundary matching algorithm to estimate the MVs and the directional interpolation EC algorithm to estimate the DVs of the erroneous MBs. After that, the Bayesian Kalman filter (BKF) is employed because of its efficiency to filter out the inherent errors in the previously predicted DVs and MVs to accomplish better 3D video performance. Experimental results on standard 3DV sequences demonstrate that the suggested BKF-based EC scheme is more powerful with heavy losses. It subjectively and objectively outperforms the traditional concealment techniques at severely random and bursty packet loss rates (PLRs).

Distributed Speech Recognition (DSR) systems rely on efficient transmission of speech information from distributed clients to a centralized server. Wireless or network communication channels within DSR systems are typically noisy and bursty. Thus, DSR systems must utilize efficient Error Recovery (ER) schemes during transmission of speech information. Some ER strategies, referred to as forward error control (FEC), aim to create redundancy in the source coded bitstream to overcome the effect of channel errors, while others are designed to create spread or delay in the feature stream in order to overcome the effect of bursty channel errors. Furthermore, ER strategies may be designed as a combination of the previously described techniques. This chapter presents an array of error recovery techniques for remote speech recognition applications. This chapter is organized as follows. First, channel characterization and modeling are discussed. Next, media-specific FEC is presented for packet erasure applications, followed by a discussion on media-independent FEC techniques for bit error applications, including general linear block codes, cyclic codes, and convolutional codes. The application of unequal error protection (UEP) strategies utilizing combinations of the aforementioned FEC methods is also presented. Finally, framebased interleaving is discussed as an alternative to overcoming the effect of bursty channel erasures. The chapter concludes with examples of modern standards for channel coding strategies for distributed speech recognition (DSR). 8.1. Distributed Speech Recognition Systems Throughout this chapter various error recovery and detection techniques are discussed. It is therefore necessary to present an overview of a complete experimental DSR system, including feature extraction, a noisy channel model, and an automatic speech recognition engine at the server end (Fig. 8.1). 2 Bengt J. Borgstrom, Alexis Bernard, and Abeer Alwan Feature Extraction Source Coding Channel Coding Channel Decoding Source Decoding Speech Recognition Client Server Noisy Channel input speech

In this paper, a new ultra wideband (UWB) circular antenna array (UCAA) combining particle swarm optimizer (PSO) to minimize the bit error rate (BER) is proposed. The novelties of our approach is not only choosing BER as the object function, but also consider the antenna feed length effect of each array element. The strong point of the PSO is that it can find out the solution even if the performance index cannot be formulated by simple equations. Simulation results show that the synthesized antenna array pattern is effective to focus maximum gain to the LOS path. As a result, the BER can be reduced substantially in indoor UWB communication system.

This paper focuses on various digital modulation schemes and their effect on bit error rate (BER); and to ascertain which has the lowest bit error rate. Further analysis includes: to compare bit error rates of various digital modulation schemes using the M-ary modulation technique, analyse the effect of varying signal energy per bit to Noise ratio (E_b/N_o) on the error rate of various digital modulation schemes, analyse graphically the relationship between E_b/N_o and BER, analyse graphically the relationship between BER and M-ary number. A model-based design methodology was employed in the research using MATLAB/SIMULINK. The comparison between different M-ary (M-PAM, M-PSK, and M-QAM) (M = 2, 4, 8, 16, 32, and 64) modulation schemes in normal AWGN channel was done. By analysing the graphical illustration of E_b/N_o vs BER of these M-PSK schemes it was strongly observed that increase in the value of M causes a correspondent increase in the error rate. Therefore, as the error rate increases with increasing M; lower level should be used for long distance communication and vice versa. High level modulation techniques are always preferred for high data rate.

Orthogonal frequency division multiplexing (OFDM) is a type of digital modulation technique which is used in wireless communication systems. It is an efficient multicarrier modulation technique, in which large bandwidth is divided into parallel narrow bands each of which is modulated by different subcarriers. All the subcarriers are orthogonal to each other and hence it reduces the interference among various subcarriers. But OFDM suffers from high peak to average power ratio(PAPR), high complexity in design. The performance parameter of OFDM can be measured in terms of Bit error rate (BER). Lower the BER value, higher is the efficiency of OFDM system. Various methods are used to enhance the BER performance. Channel coding is the one way of enhancing the BER. This paper discusses the performance of OFDM using linear & cyclic block coding for different digital modulation techniques. Bit error rate (BER) is used to measure the performance of OFDM systems.

Robust watermarks are evaluated in terms of image fidelity and robustness. We extend this framework and apply reliability testing to robust watermark evaluation. Reliability is the probability that a watermarking algorithm will correctly detect or decode a watermark for a specified fidelity requirement under a given set of attacks and images. In reliability testing, a system is evaluated in terms of quality, load, capacity and performance. To measure quality that corresponds to image fidelity, we compensate for attacks to measure the fidelity of attacked watermarked images. We use the conditional mean of pixel values to compensate for valumetric attacks such as gamma correction and histogram equalization. To compensate for geometrical attacks, we use error concealment and perfect motion estimation assumption. We define capacity to be the maximum embedding strength parameter and the maximum data payload. Load is then defined to be the actual embedding strength and data payload of a watermark. To measure performance, we use bit error rate (BER) and receiver operating characteristics (ROC) and area under the curve (AUC) of the ROC curve of a watermarking algorithm for different attacks and images. We evaluate robust watermarks for various quality, loads, attacks, and images.

Modulation techniques in 5G wireless communication systems play a crucial role in meeting demands for higher data rates, lower latency, and improved connectivity. This involves optimizing power spectral density (PSD), enhancing data transmission reliability, and reducing bit error rates (BER) and interference. The objective of this paper is to evaluate primary modulation schemes used in 5G—Orthogonal Frequency Division Multiplexing (OFDM), Filter-Orthogonal Frequency Division Multiplexing (F-OFDM), Filter Bank Multi-Carrier (FBMC), and Universal Filtered Multi-Carrier (UFMC)—based on performance metrics such as PSD, BER, and signal-to-noise ratio (SNR) using MATLAB. OFDM demonstrates low BER at high SNR but faces degradation at lower SNRs, necessitating a higher SNR for maintaining low BER. F-OFDM improves BER in noisy environments through reduced out-of-band emissions and improved spectral efficiency. FBMC shows lower BER than OFDM, especially in multipath fading scenarios, despite its higher complexity. UFMC provides balanced performance with moderate BER across varying SNRs, offering a trade-off between simplicity and efficiency, with stable BER and enhanced spectral efficiency, and reduced latency compared to OFDM. Each modulation scheme in 5G presents specific strengths and weaknesses. OFDM is robust and widely used, while F-OFDM, FBMC, and UFMC enhance spectral efficiency, BER, and SNR management. Selecting the appropriate technique depends on network requirements, with MATLAB simulations playing a crucial role in optimizing 5G network performance.

The performance analysis of multiuser multiple-input multiple-output (MIMO) system with rate-adaptive modulation and antenna selection over Rayleigh fading channels is presented. By means of exact expression of bit error rate (BER), the suboptimal switching thresholds (ST) of fading gain subject to a target BER constraint are derived. It is shown that this suboptimal ST are very close to the optimal ST, and is more accurate than the conventional ST based on approximate BER expression. By the ST, we obtain exact closed-form expressions of the spectrum efficiency (SE) and average BER. Moreover, a tightly approximate BER is derived to simplify the calculation of exact BER, which has more accuracy than the existing approximate BER. Simulation results for SE and BER are in good agreement with the derived theoretical expressions. The results show that the multiuser MIMO with adaptive modulation can provide better SE than the single user counterpart, and the system SE using suboptimal ST is also higher than that using conventional ST.

The paper considers the problem of constructing adaptive minimum bit error rate (MBER) neural network equalisers for binary signalling. Motivated from a kernel density estimation of the bit error rate (BER) as a smooth function of training data, a stochastic gradient algorithm called the least bit error rate (LBER) is developed for adaptive nonlinear equalisers. This LBER algorithm is applied to adaptive training of a radial basis function (RBF) equaliser in a channel intersymbol interference (ISI) plus co-channel interference setting. A simulation study shows that the proposed algorithm has good convergence speed, and a small-size RBF equaliser trained by the LBER can closely approximate the performance of the optimal Bayesian equaliser. The results also demonstrate that the standard adaptive algorithm, the least mean square (LMS), performs poorly for neural network equalisers because the minimum mean square error (MMSE) is clearly suboptimal in the equalisation setting.

Optical Bit Error Rate: An Estimation Methodology provides an analytical methodology to the estimation of bit error rate of optical digital signals. This presents an extremely important subject in the design of optical communications systems and networks, yet previous to the publication of this book the topic had not been covered holistically. The text lays out an easy-to-understand analytical approach to a highly important and complex subject: bit error rate (BER) estimation of a transmitted signal with a focus on optical transmission. It includes coverage of such important topics as impairments on DWDM optical signals, causes of signal distortion, and identification and estimation of the signal quality by statistical estimation of the bit error rate. The book includes numerous illustrations and examples to make a difficult topic easy to understand. This edition includes a CD-ROM with run-time simulations from a vendor that provides commercial software for the industry.

This paper seeks to determine the Bit Error Rates (BER) performance for feasible free space optical communication (FSOC) deployment in Namibian and South African atmospheric weather conditions. In order to achieve this objective, the Pulse Position Modulation (PPM) based BER performance model was invoked to compute various BER values in selected towns of both countries. The results showed that in winter season, BER values were generally lower than in summer season. A comparative analysis for various towns with the lowest and the highest scintillation in both countries showed that BER increases rapidly as photon count increases in towns with high scintillation index values. The BER values realized from this study could be used to simulate internet traffic QoS advantages of the FSOC links when compared to the RF technology networks. The study outcomes are likely to benefit operators, industry, regulators, governments, and researchers in understanding feasible areas of FSOC deployment in both countries.