ICASSP99 Signal Processing for Communications I

Signal Processing for Communications I
Home Full List of Titles 1: Speech Processing CELP Coding Large Vocabulary Recognition Speech Analysis and Enhancement Acoustic Modeling I ASR Systems and Applications Topics in Speech Coding Speech Analysis Low Bit Rate Speech Coding I Robust Speech Recognition in Noisy Environments Speaker Recognition Acoustic Modeling II Speech Production and Synthesis Feature Extraction Robust Speech Recognition and Adaptation Low Bit Rate Speech Coding II Speech Understanding Language Modeling I 2: Speech Processing, Audio and Electroacoustics, and Neural Networks Acoustic Modeling III Lexical Issues/Search Speech Understanding and Systems Speech Analysis and Quantization Utterance Verification/Acoustic Modeling Language Modeling II Adaptation /Normalization Speech Enhancement Topics in Speaker and Language Recognition Echo Cancellation and Noise Control Coding Auditory Modeling, Hearing Aids and Applications of Signal Processing to Audio and Acoustics Spatial Audio Music Applications Application - Pattern Recognition & Speech Processing Theory & Neural Architecture Signal Separation Application - Image & Nonlinear Signal Processing 3: Signal Processing Theory & Methods I Filter Design and Structures Detection Wavelets Adaptive Filtering: Applications and Implementation Nonlinear Signals and Systems Time/Frequency and Time/Scale Analysis Signal Modeling and Representation Filterbank and Wavelet Applications Source and Signal Separation Filterbanks Emerging Applications and Fast Algorithms Frequency and Phase Estimation Spectral Analysis and Higher Order Statistics Signal Reconstruction Adaptive Filter Analysis Transforms and Statistical Estimation Markov and Bayesian Estimation and Classification 4: Signal Processing Theory & Methods II, Design and Implementation of Signal Processing Systems, Special Sessions, and Industry Technology Tracks System Identification, Equalization, and Noise Suppression Parameter Estimation Adaptive Filters: Algorithms and Performance DSP Development Tools VLSI Building Blocks DSP Architectures DSP System Design Education Recent Advances in Sampling Theory and Applications Steganography: Information Embedding, Digital Watermarking, and Data Hiding Speech Under Stress Physics-Based Signal Processing DSP Chips, Architectures and Implementations DSP Tools and Rapid Prototyping Communication Technologies Image and Video Technologies Automotive Applications / Industrial Signal Processing Speech and Audio Technologies Defense and Security Applications Biomedical Applications Voice and Media Processing Adaptive Interference Cancellation 5: Communications, Sensor Array and Multichannel Source Coding and Compression Compression and Modulation Channel Estimation and Equalization Blind Multiuser Communications Signal Processing for Communications I CDMA and Space-Time Processing Time-Varying Channels and Self-Recovering Receivers Signal Processing for Communications II Blind CDMA and Multi-Channel Equalization Multicarrier Communications Detection, Classification, Localization, and Tracking Radar and Sonar Signal Processing Array Processing: Direction Finding Array Processing Applications I Blind Identification, Separation, and Equalization Antenna Arrays for Communications Array Processing Applications II 6: Multimedia Signal Processing, Image and Multidimensional Signal Processing, Digital Signal Processing Education Multimedia Analysis and Retrieval Audio and Video Processing for Multimedia Applications Advanced Techniques in Multimedia Video Compression and Processing Image Coding Transform Techniques Restoration and Estimation Image Analysis Object Identification and Tracking Motion Estimation Medical Imaging Image and Multidimensional Signal Processing Applications I Segmentation Image and Multidimensional Signal Processing Applications II Facial Recognition and Analysis Digital Signal Processing Education Author Index A B C D E F G H I J K L M N O P Q R S T U V W X Y Z	Error Probabilities and Performance Comparisons of FFH/BFSK Receivers with Multitone Jamming and AWGN Authors: Kah C Teh, Centre for Wireless Communications, National University of Singapore (Singapore) Alex C Kot, Kwok H Li, Page (NA) Paper number 1362 Abstract: This paper studies the bit-error rate (BER) performance of a fast frequency-hopped (FFH) binary frequency-shift-keying (BFSK) clipper receiver in the presence of multitone jamming~(MTJ) and additive white Gaussian noise (AWGN). By using the Taylor-series expansion and the quantization approach, the BER expressions for higher diversity levels can be obtained without much extra computational complexity. The analytical BER results, validated by simulations, show that there is an optimum diversity level for the clipper receiver. Performance comparisons among various receivers demonstrate that the BER performance of the clipper receiver is significantly better than that of the linear-combining receiver. In addition, the clipper receiver also outperforms the product-combining receiver and the self-normalizing receiver provided that the clipping threshold is set at the desired signal power level. IC991362.PDF (From Author) TOP Estimation in Cellular Radio Systems Authors: Jonas Blom, Fredrik Gunnarsson, Fredrik Gustafsson, Page (NA) Paper number 1392 Abstract: The problem to track time-varying parameters in cellular radio systems is studied, and the focus is on estimation based only on the signals that are readily available. Previous work have demonstrated very good performance, but were relying on analog measurement that are not available. Most of the information is lost due to quantization and sampling at a rate that might be as low as 2 Hz (GSM case). For that matter a Maximum Likelihood estimator have been designed and exemplified in the case of GSM. Simulations indicate good performance, both when most parameters are varying slowly, and when subject to fast variations as in realistic cases. Since most computations take place in the base stations, the estimator is ready for implementation in a second generation wireless system. No update of the software in the mobile stations is needed. IC991392.PDF (From Author) IC991392.PDF (Rasterized) TOP BER Computation Of An MC-CDMA System With Carrier Frequency Offset Authors: Younsun Kim, Sooyong Choi, Chulwoo You, Daesik Hong, Page (NA) Paper number 1591 Abstract: The effect of carrier frequency on the performance of an MC-CDMA (Multi-Carrier Code Division Multiple Access) system is considered. Bit error probability of the downlink of this system is analyzed taking into the effect of frequency offset. This paper will be focused on the derivation of the bit error probability mathematically. Derived results show that the performance of MC-CDMA is very sensitive even to a relatively minute degree of frequency offset. Parameters such as degree of carrier offset, number of subcarriers, number of users, method of combining, and type of channel will be varied so that the influence of each parameter can be assessed IC991591.PDF (Scanned) TOP FM Interference Suppression in Spread Spectrum Communications Using Time-Varying Autoregressive Model Based Instantaneous Frequency Estimation Authors: Peijun Shan, The Bradley Department of Electrical and Computer Engineering, VIRGINIA TECH, Blacksburg, Virginia 24061-0111, USA (USA) A. A. (Louis) Beex, The Bradley Department of Electrical and Computer Engineering, VIRGINIA TECH, Blacksburg, Virginia 24061-0111, USA (USA) Page (NA) Paper number 1585 Abstract: In case of a strong frequency modulated interference in a spread spectrum communication system, the interference can be effectively suppressed by applying a time-varying notch filter with its zero(s) placed at an instantaneous frequency (IF) estimate of the interference. In this paper, we present the use of a time-varying autoregressive model based IF estimator in such a scenario. We model the received signal with an autoregressive model whose coefficients are time-varying and modeled as a combination of a set of known functions of time. The IF of the interference is estimated from the model. It is demonstrated that this method provides superior performance compared to using a time-frequency distribution. The comparison reveals that the Wigner-Ville Distribution peak based IF estimator suffers drawbacks such that its filtering gain is limited. IC991585.PDF (From Author) IC991585.PDF (Rasterized) TOP Equalization of Satellite UMTS Channels Using Neural Network Devices Authors: Steven Bouchired, Mohamed Ibnkahla, Daniel Roviras, Francis Castanié, Page (NA) Paper number 1299 Abstract: The presence of non-linear devices in several communication channels, such as satellite channels, causes distortions of the transmitted signal. These distortions are more severe for non-constant envelope modulations such as 16-QAM. Over the last years Neural Networks (NN) have emerged as competitive tools for linear and non-linear channel equalization. However, their main drawback is often slow convergence speed which results in poor tracking capabilities. The present paper combines simple NN structures with conventional equalizers. The NN techniques are shown to efficiently approximate the optimal decision boundaries which results in good symbol error rate (SER) performance. The paper gives simulation examples (in the context of satellite mobile channels) and compares neural network approaches to classical equalization techniques. IC991299.PDF (From Author) IC991299.PDF (Rasterized) TOP Hopped Linear Time-Varying Filters: Principles Authors: Aawatif Hayar, Daniel Roviras, Bernard Lacaze, Alban Duverdier, Page (NA) Paper number 1648 Abstract: Privacy and security of radio communications becomes increasingly important. In this context, modulation techniques with embedded scrambling properties are suitable. The aim of this paper is to present a new transmitting technique using Linear Time Varying Filters with hopping in the frequency domain. IC991648.PDF (From Author) IC991648.PDF (Rasterized) TOP Low Complexity Source Controlled Channel Decoding in a GSM System Authors: Paul Strauch, Carlo Luschi, Magnus Sandell, Ran Yan, Page (NA) Paper number 1956 Abstract: In this paper we investigate source controlled channel decoding with a hard output channel decoder. Various methods have been devised in the past for source controlled channel decoding, but most of them assume that a soft output channel decoder is used. Most receivers in mobile wireless communications have a standard Viterbi channel decoder which produces only hard outputs. It is shown that a simple sliding histogram is capable of improving the speech quality significantly. The ideas and methods in this paper are applied for the full-rate and enhanced full-rate speech codecs in the GSM system. IC991956.PDF (From Author) IC991956.PDF (Rasterized) TOP Applying GCMAC To Predistortion In GSM Base Stations Authors: Juan Jose Murillo-Fuentes, Francisco J. González-Serrano, Page (NA) Paper number 1445 Abstract: Predistortion in GSM has been introduced to deal with saturation in amplification at Base Transceiver Stations (BTS). This paper will focus on the elements and architectures in signal predistortion for mone carrier and multicarrier modulations. The GCMAC neural network has been introduced as predistorter to provide the design with adaptive, digital and practical features. Some results are included. These results show how the predistortion architectures proposed allows working in saturation regimen. This point is important since it gives flexibility in reassignment of cells by increasing the coverage when necessary. It also improves amplification characteristics avoiding co-channel interference, aging, intermodulation distortion, etc. IC991445.PDF (From Author) IC991445.PDF (Rasterized) TOP Burst Error Compensation for a Two-Dimensional Channel Authors: J. Q Trelewicz, Andrew J Siefker, Page (NA) Paper number 2226 Abstract: In an optical channel for a digital holographic data storage system, burst errors, in the form of severe amplitude compression, are experienced in the vicinity of dust and other optical aberrations in the channel. The locations of these burst errors are approximately fixed over a range of perturbations in magnification and vertical-horizontal position. In a calibrated channel, lower error rates can be realized by allocating energy in the modulation code based on a measurement of the approximate location of these effects. This paper discusses theoretical bounds on the energy inside the distortion region, and the modulation code which is used to approach this bound. 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