The Experts below are selected from a list of 5172 Experts worldwide ranked by ideXlab platform
Joseph M. Kahn - One of the best experts on this subject based on the ideXlab platform.
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Joint Design of a Channel-Optimized Quantizer and Multicarrier Modulation
2013Co-Authors: Joseph M. KahnAbstract:Abstract — We present an algorithm for design of a joint source-channel coder using a channel-optimized quantizer and Multicarrier Modulation. By changing the power of each subchannel in the Multicarrier Modulation system, different degrees of error protection can be provided for different bits according to their importance. The algorithm converges to a locally optimum system design. Compared to a Lloyd–Max scalar quantizer or a LBG vector quantizer using single-channel transmission, our optimized code can yield substantial performance improvements. The performance improvements are most pronounced at low channel signal-to-noise ratios. Index Terms — Combined source-channel coding, Multicarrier Modulation, vector quantization
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joint design of a channel optimized quantizer and Multicarrier Modulation
IEEE Transactions on Communications, 1998Co-Authors: Joseph M. KahnAbstract:We present an algorithm for design of a joint source-channel coder using a channel-optimized quantizer and Multicarrier Modulation. By changing the power of each subchannel in the Multicarrier Modulation system, different degrees of error protection can be provided for different bits according to their importance. The algorithm converges to a locally optimum system design. Compared to a Lloyd-Max scalar quantizer or a LBG vector quantizer using single-channel transmission, our optimized code can yield substantial performance improvements. The performance improvements are most pronounced at low channel signal-to-noise ratios.
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Image transmission over noisy channels using Multicarrier Modulation
Signal Processing: Image Communication, 1997Co-Authors: Joseph M. KahnAbstract:Abstract We have proposed and analyzed a combined source-channel coding scheme using Multicarrier Modulation. By changing the power and Modulation of subchannels carrying different bits of the compressed signal, the channel-induced distortion can be minimized. An algorithm for the subchannel power allocation is derived. As an example, for DCT- and subbandcoded images, Multicarrier systems using uncoded BPSK achieve more than a 9 dB improvement over single-carrier systems in terms of the image signal-to-distortion ratio on very noisy channels.
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Combined source-channel coding using channel-optimized quantizer and Multicarrier Modulation
Proceedings of ICC SUPERCOMM '96 - International Conference on Communications, 1Co-Authors: Joseph M. KahnAbstract:We present an algorithm for design of a joint source-channel coder using a channel-optimized quantizer and Multicarrier Modulation. By changing the power of each subchannel in the Multicarrier Modulation system, different error protection can be provided for different bits according to their importance. The algorithm converges to a locally optimum system design. Compared to a Lloyd-Max (1982, 1960) scalar quantizer or a LBG vector quantizer using single-channel transmission, our optimized system can yield substantial performance improvements. The performance improvements are most pronounced at low channel signal-to-noise ratios.
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Combined source-channel coding using Multicarrier Modulation
Conference Record of The Twenty-Ninth Asilomar Conference on Signals Systems and Computers, 1Co-Authors: Joseph M. KahnAbstract:We propose a combined source-channel coding scheme using Multicarrier Modulation to minimize the distortion in the transmission of analog sources Different degrees of error protection can be provided for different bits by changing the power Modulation, and channel coding of the respective subchannels, such that the overall distortion of the source is minimized. For a Gaussian source quantized to 8 bits and transmitted over a AWGN channel, a 13-dB reduction in channel-induced distortion can be obtained.
Chinliang Wang - One of the best experts on this subject based on the ideXlab platform.
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discrete hartley transform based Multicarrier Modulation
International Conference on Acoustics Speech and Signal Processing, 2000Co-Authors: Chinliang Wang, Chinghsien Chang, J L Fan, J M CioffiAbstract:This paper presents a real-valued discrete Multicarrier Modulation approach that is based on the use of the discrete Hartley transform (DHT) and its inverse (IDHT) to perform the Modulation and deModulation operations. Since the DHT and IDHT definitions are identical, we can use the same hardware or program to implement the modulator and demodulator of the proposed Multicarrier method. As compared to the complex-valued discrete Fourier transform based Multicarrier Modulation method, the proposed one achieves the same transmission performance with reduced computational complexity and implementation cost.
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ICASSP - Discrete Hartley transform based Multicarrier Modulation
2000 IEEE International Conference on Acoustics Speech and Signal Processing. Proceedings (Cat. No.00CH37100), 1Co-Authors: Chinliang Wang, Chinghsien Chang, J L Fan, John M. CioffiAbstract:This paper presents a real-valued discrete Multicarrier Modulation approach that is based on the use of the discrete Hartley transform (DHT) and its inverse (IDHT) to perform the Modulation and deModulation operations. Since the DHT and IDHT definitions are identical, we can use the same hardware or program to implement the modulator and demodulator of the proposed Multicarrier method. As compared to the complex-valued discrete Fourier transform based Multicarrier Modulation method, the proposed one achieves the same transmission performance with reduced computational complexity and implementation cost.
Haixia Zhang - One of the best experts on this subject based on the ideXlab platform.
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A study on the PAPRs in Multicarrier Modulation systems with different orthogonal bases
Wireless Communications and Mobile Computing, 2007Co-Authors: Haixia Zhang, Dongfeng Yuan, Cheng-xiang WangAbstract:This paper studies the peak-to-average power ratios (PAPRs) in Multicarrier Modulation (MCM) systems with seven different orthogonal bases, one Fourier base and six wavelet bases. It is shown by simulation results that the PAPRs of the Fourier-based MCM system are lower than those of all wavelet-based MCM (WMCM) systems. A novel threshold-based PAPR reduction method is then proposed to reduce the PAPRs in WMCM systems. Both numerical and simulation results indicate that the proposed PAPR reduction method works very effectively in WMCM systems. Copyright © 2006 John Wiley & Sons, Ltd.
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ISIT - Threshold method to reduce PAPR in wavelet based Multicarrier Modulation systems
Proceedings. International Symposium on Information Theory 2005. ISIT 2005., 2005Co-Authors: Haixia Zhang, Dongfeng Yuan, Feng ZhaoAbstract:A novel peak to average power ratio (PAPR) reduction method, threshold method, for wavelet based Multicarrier Modulation (WMCM) systems is proposed and presented in this paper. Theory analysis and simulation results both prove that our proposed PAPR reduction method to be a feasible and efficient one for Multicarrier Modulation system (MCM)
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Research of PAPR reduction method in Multicarrier Modulation system
Proceedings. 2005 International Conference on Communications Circuits and Systems 2005., 1Co-Authors: Haixia Zhang, Dongfeng Yudo, Feng ZhaoAbstract:Utilizing the advantage of concentrating energy to certain parts of the discrete wavelet transform (DWT), a novel peak to average power ratio (PAPR) reduction method of Multicarrier Modulation (MCM) systems is presented in this paper. Using the new scheme PAPR of MCM system can be greatly reduced with a little bit error rate (BER) lost. Theoretical analysis and simulation results prove that the proposed method is an efficient way for reducing PAPR.
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Performance analysis of different basis in Multicarrier Modulation system over time-variant channels
Proceedings. 2005 International Conference on Communications Circuits and Systems 2005., 1Co-Authors: Yupeng Jia, Haixia Zhang, Dongfeng Yuan, Xinying GaoAbstract:In this paper the performance of different basis in Multicarrier Modulation (MCM) system over time-variant channels are analyzed and filter banks generated by different orthogonal Daubechies wavelets and bi-orthogonal wavelets are tested and compared. Due to the high spectral containment of wavelet filters, the wavelet packet MCM (WP-MCM) system performs better than the Fourier based MCM system over time-variant channels.
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PIMRC - Performance analysis of different basis in turbo coded Multicarrier Modulation system
2005 IEEE 16th International Symposium on Personal Indoor and Mobile Radio Communications, 1Co-Authors: Yupeng Jia, Haixia Zhang, Dongfeng Yuan, Xinying GaoAbstract:In this paper performance of different basis in Multicarrier Modulation (MCM) system over time-variant channels are analyzed and filter bank generated by different orthogonal Daubechies wavelets and bi-orthogonal wavelets are tested and compared. Due to the high spectral containment of wavelet filters, the wavelet packet MCM (WP-MCM) system performs better than Fourier based MCM system over time-variant channels. With turbo code applied in WP-MCM system, the BER performance improves greatly over time-variant channels with few iterations in the regions of low signal to noise ratio
Li Hui-min - One of the best experts on this subject based on the ideXlab platform.
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Peak-to-Average Power Ratio in Wavelet Packet Transform-Based Multicarrier Modulation
Journal of Tianjin University, 2006Co-Authors: Li Hui-minAbstract:The definition of the peak-to-average power ratio (PAPR) in wavelet packet transform-based Multicarrier Modulation( WPT-MCM) is given according to the structure of the WPT-MCM system. The effect of the number of subcarrier on the PAPR is analyzed, the properties of PAPR in WPT-MCM system and in orthogonal frequency-division multiplexing( OFDM) system are compared by simulations. A method based on selected mapping ( SLM) technique is then proposed to reduce the PAPR in WPT-MCM system. The results show that the increase of the number of subcarrier leads to the increase of the PAPR, and the method based on SLM technique can decrease the PAPR in WPT-MCM system effectively.
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PAPR analysis and reduction in wavelet packet based Multicarrier Modulation
Journal of Tianjin Institute of Technology, 2005Co-Authors: Li Hui-minAbstract:According to the analysis of the wavelet packet based Multicarrier Modulation,the definition and the arithmetic method of the Peak to Average Power Ratio(PAPR) are given in this article.A procedure based on Selected Mapping(SLM) technique is then proposed in order to decrease the PAPR.Some simulations are carried to support the analysis.
J M Cioffi - One of the best experts on this subject based on the ideXlab platform.
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discrete hartley transform based Multicarrier Modulation
International Conference on Acoustics Speech and Signal Processing, 2000Co-Authors: Chinliang Wang, Chinghsien Chang, J L Fan, J M CioffiAbstract:This paper presents a real-valued discrete Multicarrier Modulation approach that is based on the use of the discrete Hartley transform (DHT) and its inverse (IDHT) to perform the Modulation and deModulation operations. Since the DHT and IDHT definitions are identical, we can use the same hardware or program to implement the modulator and demodulator of the proposed Multicarrier method. As compared to the complex-valued discrete Fourier transform based Multicarrier Modulation method, the proposed one achieves the same transmission performance with reduced computational complexity and implementation cost.
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impulse noise mitigation strategies for Multicarrier Modulation
International Conference on Communications, 1993Co-Authors: T N Zogakis, Peter Chow, J T Aslanis, J M CioffiAbstract:Short time-duration and high magnitude noise, taking on the form of time-domain impulse noise over copper twisted-pairs or multipath fading in wireless communication, can potentially be the limiting impairment on performance in many high-speed data transmission applications. Coding techniques are presented, designed specifically for Multicarrier modulated systems to mitigate the effects of such impairment. Several coding combinations, involving soft error protection, in addition to hard forward error correction, are considered. The techniques can be applied with minor variation to a number of possible applications employing Multicarrier Modulation, including wireless digital audio broadcasting (DAB) systems and high-speed data/video transmission over coaxial cables. >