ISSPA '99. Proceedings of the Fifth International Symposium on Signal Processing and its Applications (IEEE Cat. No.99EX359)最新文献

{"title":"Detection of signals using digital generalized detector","authors":"V. Tuzlukov","doi":"10.1109/ISSPA.1999.818140","DOIUrl":"https://doi.org/10.1109/ISSPA.1999.818140","url":null,"abstract":"This article is concerned with the problems of using the digital generalized detector for detection of weak signals. The signal-to-noise ratio (SNR) at the output of the detector is determined under conditions that the input SNR is significantly below one. SNR losses at the output of the detector arising as a consequence of clipping, sampling and amplitude quantization are determined as a function of the spectrum bandwidth of the signal at the detector input and sampling rate under three various energy spectrums of the input signals. Comparative analysis between the digital generalized detector and optimum detectors of classical and modern theories is carried out. Comparative analysis demonstrates the superiority of the generalized detector over the optimum detectors.","PeriodicalId":302569,"journal":{"name":"ISSPA '99. Proceedings of the Fifth International Symposium on Signal Processing and its Applications (IEEE Cat. No.99EX359)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130588936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance of adaptive predistortion temperature in RF power amplifier linearization","authors":"H. He, M. Faulkner","doi":"10.1109/ISSPA.1999.815772","DOIUrl":"https://doi.org/10.1109/ISSPA.1999.815772","url":null,"abstract":"The input-output AM/AM and AM/PM characteristics of an RF power amplifier varies with junction temperature. A thermal model of a power amplifier (PA) is built by using thermal impedance curves of a power transistor. Based on this model, the dynamic performance of a PA is simulated under different input signal conditions, with and without predistortion. It is shown that variations in junction temperature due to input signal modulation have an insignificant effect on the performance of predistortion linearization, but variations due to longer term average power dissipation degrade the performance and must be tracked.","PeriodicalId":302569,"journal":{"name":"ISSPA '99. Proceedings of the Fifth International Symposium on Signal Processing and its Applications (IEEE Cat. No.99EX359)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115093058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Automatic recognition of digitally modulated communications signals","authors":"V. Ramakomar, D. Habibi, A. Bouzerdoum","doi":"10.1109/ISSPA.1999.815781","DOIUrl":"https://doi.org/10.1109/ISSPA.1999.815781","url":null,"abstract":"This paper introduces an algorithm that extends the capability of digital modulations classifiers to cope with signals that have memory incorporated in their modulation scheme. The algorithm employs the decision-theoretic approach where the identification of different modulation types is performed by developing a set of decision criteria. The performance of the classifier has been evaluated by simulating different types of bandlimited digital signals corrupted by Gaussian noise. It is shown that the overall success rate is over 94% at the signal to noise ratio (SNR) of 10 dB with some modulation schemes detected with success rate of 100% at this SNR.","PeriodicalId":302569,"journal":{"name":"ISSPA '99. Proceedings of the Fifth International Symposium on Signal Processing and its Applications (IEEE Cat. No.99EX359)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130309754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An efficient strategy for development of flexible learning material","authors":"Peter J. O'Shea","doi":"10.1109/ISSPA.1999.815729","DOIUrl":"https://doi.org/10.1109/ISSPA.1999.815729","url":null,"abstract":"In recent times, there has been a proliferation of activity in the area of flexible learning for tertiary institutions. Some of the reasons for this interest are that: (1) students have more options as to when and how they will learn; (2) distance education is far more practical; (3) staff teaching time can be reduced substantially in the long term; and (4) the computer animation achievable through currently available multimedia tools can enable more effective learning of difficult concepts; etc. Despite the potential benefits, the percentage of academic staff actively pursuing development of flexible delivery units in their courses is small. The reason for this reluctance is the seemingly daunting amount of effort required to produce the necessary multimedia tools. The time required to become proficient in multimedia packages is in itself a major deterrent. This paper describes one methodology for surprisingly efficient development of flexible delivery materials. The key to the methodology is to perform the development in a sequence of stages. The stages are designed so that useful products are available at the completion of all stages, even the first one. The approach has been trialed at RMIT with very encouraging success-class contact time has been substantially reduced and students are happy about the changes.","PeriodicalId":302569,"journal":{"name":"ISSPA '99. Proceedings of the Fifth International Symposium on Signal Processing and its Applications (IEEE Cat. No.99EX359)","volume":"260 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133794369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new channel model for ADSL and VDSL systems","authors":"D. Franklin, J. Chicharo, J. Xi","doi":"10.1109/ISSPA.1999.815778","DOIUrl":"https://doi.org/10.1109/ISSPA.1999.815778","url":null,"abstract":"This paper presents a new model for telephone lines which is intended for use in simulations of digital subscriber line (DSL) telecommunications systems. It combines the broadband filter characteristics of the line with an improved noise model, which acknowledges the fact that the point of ingress of impulse noise events may be anywhere along the length the line. Since impulse noise is a major impediment to DSL systems, such a model is expected to offer advantages over simpler models. A method for determining the parameters of this model is also proposed.","PeriodicalId":302569,"journal":{"name":"ISSPA '99. Proceedings of the Fifth International Symposium on Signal Processing and its Applications (IEEE Cat. No.99EX359)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133892155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A systolic filter for low-level processing of the discrete wavelet transform","authors":"N. Dunstan","doi":"10.1109/ISSPA.1999.815838","DOIUrl":"https://doi.org/10.1109/ISSPA.1999.815838","url":null,"abstract":"The discrete wavelet transform requires repeated high and low pass filtering of data scan lines. There has been a variety of special purpose devices and parallel algorithms designed to speedup this computationally intensive process. This paper describes a systolic filter intended for low-level processing of data scan lines. This processing is required for one-dimensional and higher dimensional DWT. Operations required by high and low pass filtering are interleaved on a single pipelined processor array. The filter has multirate characteristics. Implementation in reconfigurable hardware with dynamic reconfiguration is discussed.","PeriodicalId":302569,"journal":{"name":"ISSPA '99. Proceedings of the Fifth International Symposium on Signal Processing and its Applications (IEEE Cat. No.99EX359)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132995491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Digital AM-VSB modulator for compatible PAL systems","authors":"G. Redaelli, E. Gasparetto, G. Burzi","doi":"10.1109/ISSPA.1999.815786","DOIUrl":"https://doi.org/10.1109/ISSPA.1999.815786","url":null,"abstract":"This paper presents the design of a digital vestigial modulator with the partial suppression of the upper sideband of the composite PAL signal. The choices made during the digital implementation of this device allow to shift the digital-to-analog conversion of the TV signal to intermediate frequency while ensuring the full compatibility with analog transmission systems and the TV receivers currently in use. Particular emphasis is devoted both to the description of the two original schemes proposed for the AM-VSB modulator and to the optimization of the system performance, taking the influence of the most significant parameters of digital filters into account.","PeriodicalId":302569,"journal":{"name":"ISSPA '99. Proceedings of the Fifth International Symposium on Signal Processing and its Applications (IEEE Cat. No.99EX359)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133196641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parallel computation of the bispectrum","authors":"K. Le, G. Egan, K. Dabke","doi":"10.1109/ISSPA.1999.818160","DOIUrl":"https://doi.org/10.1109/ISSPA.1999.818160","url":null,"abstract":"This paper investigates the effectiveness of parallel computing in the calculation of the bispectrum. The bispectrum is estimated by using two different methods namely the direct and the indirect. The direct method employs 1-D FFT algorithms and the indirect method employs the 2-D FFT algorithm to estimate the bispectrum. Both methods have been implemented using 2 different parallel programming techniques: semi-automatic and fully automatic using the Power C Analyzer (PCA). The Silicon Graphics Power Challenge Multiprocessor System (with 12 CPUs) is used to run the parallel codes. Near-linear speedup was observed by employing both techniques. Overall, the maximum speedup of 10.84 at N=12 can be achieved for the direct method and of 8.7 at N=10 for the indirect method using the semi-automatic parallel technique. For the PCA fully parallel technique, the maximum measured speedup for the direct and indirect methods are 10.07 at N=11 and 7.67 at N=12 respectively.","PeriodicalId":302569,"journal":{"name":"ISSPA '99. Proceedings of the Fifth International Symposium on Signal Processing and its Applications (IEEE Cat. No.99EX359)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134630264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bounds on capacity improvements using spatial filtering","authors":"H. Jones, P. Rapajic, R. Kennedy","doi":"10.1109/ISSPA.1999.815837","DOIUrl":"https://doi.org/10.1109/ISSPA.1999.815837","url":null,"abstract":"The relationship between the information capacity and the corresponding beam pattern of a multi-sensor array is investigated. From this, bounds on the information capacity improvements possible utilizing spatial filtering in a multiuser environment are established.","PeriodicalId":302569,"journal":{"name":"ISSPA '99. Proceedings of the Fifth International Symposium on Signal Processing and its Applications (IEEE Cat. No.99EX359)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130961128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling speech production and perception mechanisms and their applications to synthesis, recognition, and coding","authors":"A. Alwan","doi":"10.1109/ISSPA.1999.818096","DOIUrl":"https://doi.org/10.1109/ISSPA.1999.818096","url":null,"abstract":"Summary form only given, as follows. Quantitative models of human speech production and perception mechanisms provide important insights into our cognitive abilities and can lead to high-quality speech synthesis, robust automatic speech recognition and coding schemes, and better speech and hearing prostheses. Some of our research activities in these two areas are described. Our speech production work involved collecting, and analyzing magnetic resonance images (MRI), acoustic recordings, and electropalatography (EPG) data from talkers of American English during speech production. The articulatory database is the largest of its kind in the world and contains the first images of liquids (such as /I/ and /r/) and fricatives (such as /s/ and /sh) for both male and female talkers. MR images are useful for characterizing the 3D geometry of the vocal tract (VT) and for measuring lengths, area functions, and volumes. EPG is used to study inter- and intra-speaker variabilities in the articulatory dynamics, while acoustic recordings are necessary for modeling. Inter- and intra-speaker characteristics of the VT and tongue shapes will be illustrated for various speech sounds, as well as results of acoustic modeling based on the MRI and acoustic data. The implications of our findings on vocal-tract normalization schemes and speech synthesis are also discussed. In the speech perception area, aspects of auditory signal processing and speech perception are parameterized and implemented in a speech recognition system. Our models parameterize the sensitivity to spectral dynamics and local peak frequency positions in the speech signal. These cues remain robust when listening to speech in noise. Recognition evaluations using the dynamic model with a stochastic hidden Markov model (HMM) recognition system showed increased robustness to noise over other state-of-the-art representations. The applications of auditory modeling to speech coding are discussed. We developed an embedded and perceptually-based speech and audio coder. Perceptual metrics are used to ensure that encoding is optimized to the human listener and is based on calculating the signal-to-mask ratio in short-time frames of the input signal. An adaptive bit allocation scheme is employed and the subband energies are then quantized. The coder is variable-rate, noise-robust and suitable for wireless communications.","PeriodicalId":302569,"journal":{"name":"ISSPA '99. Proceedings of the Fifth International Symposium on Signal Processing and its Applications (IEEE Cat. No.99EX359)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131120641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}