IEEE TRANSACTIONS ON COMMUNICATIONS, ACCEPTED FOR PUBLICATION 1 Decision Boundary Evaluation of Optimum and Suboptimum Detectors in Class-A Interference

Abstract-The Middleton Class-A (MCA) model is one of the most accepted models for narrow-band impulsive interference superimposed to additive white Gaussian noise (AWGN). The MCA density consists of a weighted linear combination of infinite Gaussian densities, which leads to a non-tractable form of the optimum detector. To reduce the receiver complexity, one can start with a two-term approximation of the MCA model, which has only two noise states (Gaussian and impulsive state). Our objective is to introduce a simple method to estimate the noise state at the receiver and accordingly, reduce the complexity of the optimum detector. Furthermore, we show for the first time how the decision boundaries of binary signals in MCA noise should look like. In this context, we provide a new analysis of the behavior of many suboptimum detectors such as a linear detector, a locally optimum detector (LOD), and a clipping detector. Based on this analysis, we insert a new clipping threshold for the clipping detector, which significantly improves the bit-error rate performance

Distributed-parameter state-variable techniques applied to communication over dispersive channels.

Massachusetts Institute of Technology. Dept. of Electrical Engineering. Thesis. 1969. Sc.D.MICROFICHE COPY ALSO AVAILABLE IN BARKER ENGINEERING LIBRARY.Vita.Bibliography: leaves 275-277.Sc.D

Cooperative Diversity for Fading Channels in the Presence of Impulsive Noise

Although there already exists a rich literature on cooperative diversity, current results are mainly restricted to the conventional assumption of additive white Gaussian noise (AWGN). AWGN model realistically represents the thermal noise at the receiver, but ignores the impulsive nature of atmospheric noise, electromagnetic interference, or man-made noise which might be dominant in many practical applications. In this thesis, we investigate the performance of cooperative communication over Rayleigh fading channels in the presence of impulsive noise modeled by Middleton Class A noise. We consider a multi-relay network with amplify-and-forward relaying and orthogonal cooperation protocol. As for the coding across the relays, we employ either space-time coding or repetition coding. For each scheme, we assume various scenarios based on relays’ location and quantify the diversity advantages through the derivation of the pairwise error probability. Based on the minimization of a union bound on the error rate performance, we further propose optimal power allocation schemes and demonstrate significant performance gains over their counterparts with equal power allocation. We finally present an extensive Monte Carlo simulation to confirm our analytical results and corroborate on our results

Coded modulation techniques with bit interleaving and iterative processing for impulsive noise channels

Power line communications (PLC) surfers performance degradation due mainly to impulsive noise interference generated by electrical appliances. This thesis studies coded modulation techniques to improve the spectral efficiency and error performance of PLC. Considered in the first part is the application of bit-interleaved coded modulation with iterative decoding (BICM-ID) in class-A impulsive noise environment. In particular, the optimal soft-output demodulator and its suboptimal version are presented for an additive class-A noise (AWAN) channel so that iterative demodulation and decoding can be performed at the receiver. The effect of signal mapping on the error performance of BICM-ID systems in impulsive noise is then investigated, with both computer simulations and a tight error bound on the asymptotic performance. Extrinsic information transfer (EXIT) chart analysis is performed to illustrate the convergence properties of different mappings. The superior performance of BICMID compared to orthogonal frequency-division multiplexing (OFDM) is also clearly demonstrated.Motivated by the successes of both BICM-ID and OFDM in improving the error performance of communications systems in impulsive noise environment, the second part of this thesis introduces a novel scheme of bit-interleaved coded OFDM with iterative decoding (BI-COFDM-ID) over the class-A impulsive noise channel. Here, an iterative receiver composed of outer and inner iteration loops is first described in detail. Error performance improvements of the proposed iterative receiver with different iteration strategies are presented and discussed. Performance comparisons of BI-COFDM-ID, BICM-ID and iteratively decoded OFDM are made to illustrate the superiority of BI-COFDM-ID. The effect of signal mapping on the error performance of BI-COFDM-ID is also studied

Data transmission through channels pertubed by impulsive noise

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Masreliez-Equalized VOFDM in Non-Gaussian Channels: Power Line Communication Systems

In this paper, we derive a non-linear equalizer for a fading channel with non-Gaussian noise. In particular, we look into the effects of non-Gaussian noise over power line channels that severely affect communication signals. Unlike most existing work based on orthogonal frequency-division multiplexing (OFDM) in the literature, we investigate the performance of vector OFDM (VOFDM) over multi-path power line communication (PLC) channels contaminated with Middleton Class-A noise. To reduce the impact of impulsive noise we propose a novel filter to equalize the output of the channel. The performance of the equalizer is evaluated in terms of bit error rate (BER), and the impact of several impulsive noise parameters are examined at the receiver. Results show that the proposed system can considerably improve the BER performance in comparison to the conventional OFDM scheme. In addition, it is shown that increasing the number of vector blocks of the VOFDM system will enhance the BER performance under the same condition. The proposed non-linear equalizer improves the performance of VOFDM system successfully at low signal-to-noise ratios (SNRs), at some instances it nearly halved the probability of error with respect to linear filter