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Joint matrix quantization of face parameters and LPC coefficients for low bit rate audiovisual speech coding

IEEE TRANSACTIONS ON SPEECH AND AUDIO PROCESSING 2004年第3期12卷 265-276页

作者： Girin, L Univ Grenoble 3 CNRS INPG Inst Commun Parlee F-38031 Grenoble France

A key problem for videophony, that is telephony including the processing of images of the speaker's face in addition to acoustic speech, concerns signal compression for transmission. In such systems, audio and video compression are separately achieved by using both audio and video coders. In this paper, an audio-visual approach to this problem is considered, since we claim that the fundamental property of coherence (redundancy) between the two modalities of speech should be exploited by coding systems. We consider the framework of parametric analysis, modeling and synthesis of talking faces, which allows efficient representation of video information. Thus, we propose to jointly encode several face parameters, namely lip shape geometric descriptors, together with sets of audio coefficients, namely quite usual LPC parameters. The definition of an audiovisual distance between vectors of concatenated audio and video parameters allows to generate audiovisual single stage vector and matrix quantizers by using the generalized Lloyd algorithm. Calculation of video and audio mean distortion measures shows a significant gain in quantization accuracy and/or resolution compared to separate video and audio quantization. An alternative sub-optimal tree-like structure for audiovisual joint coding is also tested and yields interesting results while decreasing the computational complexity of the quantization process.

关键词： audiovisual lip parameters low-bit-rate speech coding LPC parameters matrix quantization speech processing

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matrix quantization OF TURBULENCE

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INTERNATIONAL JOURNAL OF BIFURCATION AND CHAOS 2012年第9期22卷 1250213-1250213页

作者： Floratos, Emmanuel Univ Athens Dept Phys GR-15771 Athens Greece NCSR Demokritos Inst Nucl Phys GR-15310 Athens Greece

Based on our recent work on Quantum Nambu Mechanics [Axenides & Floratos, 2009], we provide an explicit quantization of the Lorenz chaotic attractor through the introduction of noncommutative phase space coordinates as Hermitian N x N matrices in R-3. For the volume preserving part, they satisfy the commutation relations induced by one of the two Nambu Hamiltonians, the second one generating a unique time evolution. Dissipation is incorporated quantum mechanically in a self-consistent way having the correct classical limit without the introduction of external degrees of freedom. Due to its volume phase space contraction, it violates the quantum commutation relations. We demonstrate that the Heisenberg-Nambu evolution equations for the matrix Lorenz system develop fast decoherence to N independent Lorenz attractors. On the other hand, there is a weak dissipation regime, where the quantum mechanical properties of the volume preserving nondissipative sector survive for long times.

关键词： Chaos turbulence strange attractors Nambu dynamics matrix quantization

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Combined Source Adaptive and Channel Optimized matrix quantization Algorithm

Combined Source Adaptive and Channel Optimized Matrix Quanti...

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5th International Conference on Information, Intelligence, Systems and Applications (IISA)

作者： Bozantzis, Vasilios Philippopoulos, Panos TEI Peloponnesus Sch Appl Technol Dept Comp Engn Sparti Greece

ISBN: (纸本)9781479961726

matrix quantization (MQ), a very promising source coding technique, has already been successfully applied for speech signals and noiseless channels. MQ is also shown in the literature to outperform Vector quantization (VQ) when applied over noisy channels. Considering that most sources of practical interest are non-stationary, this paper introduces a technique which adapts MQ to varying source statistics and optimizes MQ for noisy channels, thus designs a matrix quantizer/decoder that considers both non-stationary source and noisy channel statistics. The resulting algorithm, Combined Source Adaptive and Channel Optimized matrix quantization (CSACOMQ) is evaluated for a source modelled as the non-stationary Wiener process and over the memoryless Binary Symmetric Channel (BSC). It is shown that CSACOMQ offers substantial Signal-to-Noise Ratio (SNR) performance improvement compared to the Channel Optimized matrix quantization (COMQ).

关键词： matrix quantization Channel Optimization Adaptive Source Coding Combined Source-Channel Coding

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A 300bps Speech Coding Algorithm Based on Multi-Mode matrix quantization

A 300bps Speech Coding Algorithm Based on Multi-Mode Matrix ...

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International Conference on Wireless Communications and Signal Processing

作者： Zou, Xia Zhang, Xiongwei Zhang, Yafei PLA Univ Sci & Tech Nanjing 210007 Peoples R China

ISBN: (纸本)9781424448562

A 300bps speech coder based on multi-frame structure and multi-mode matrix quantization is presented. The multi-frame structure consisting of six frames is adopted to reduce the algorithm delay. The parameter matrices are classified into different modes based on the voicing vector information of superframe. To improve speech quality, a dynamic bit allocation scheme is developed. Experimental results show that the speech quality of the proposed vocoder is intelligible with good naturalness.

关键词： speech coding matrix quantization multi-mode dynamic bit allocation

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Channel optimized matrix quantization (COMQ) of LSP parameters over waveform channels

Channel optimized matrix quantization (COMQ) of LSP paramete...

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IEEE International Conference on Acoustics, Speech, and Signal Processing

作者： Pérez-Córdoba, JL Rubio, A López-Soler, JM Sánchez, VE Univ Granada Fac Ciencias Dept Elect & Tecnol Comp Granada Spain

ISBN: (纸本)0780370414

Combined source and channel coding is a technique to mitigate channel errors without increasing the bit error rate. Channel optimized vector quantizer (COVQ) [3] performs these objectives in the context of vector quantization. This paper presents a study of channel optimized matrix quantizer (COMQ) applied to quantize the Line Spectral Pair (LSP) parameters [5] as an extension of COVQ technique. Gaussian and slow-fading Rayleigh channels are considered and GMSK (Gaussian Minimum Shift-Keying) is used as modulation technique. Several channel signal to noise ratio (CSNR) are considered to measure the performance of this system. In addition, for comparison purposes, the performance of other schemes for quantizing the LSP parameters are computed.

关键词： matrix quantization joint source-channel coding COVQ COMQ LSP parameters CELP coders SMQ GSM EFR coder

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A 450bps Speech Coding Algorithm Based on Multi-mode matrix quantization

A 450bps Speech Coding Algorithm Based on Multi-mode Matrix ...

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2nd International Congress on Image and Signal Processing

作者： Zou, Xia Zhang, Xiongwei PLA Univ Sci &Tech Nanjing Peoples R China

ISBN: (纸本)9781424441303

A 450bps speech coder based on multi-frame structure and multi-mode matrix quantization is presented. The multi-frame structure consisting of four frames is adopted to reduce the algorithm delay. The parameter matrices are classified into different modes based on the voicing vector information of superframe. To improve speech quality, a dynamic bit allocation scheme is developed. Experimental results show that the speech quality of the proposed vocoder is intelligible with good naturalness.

关键词： speech coding matrix quantization multi-frame multi-mode

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Design and analysis of MIMO spatial multiplexing systems with quantized feedback

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2006年第8期54卷 2874-2886页

作者： Roh, June Chul Rao, Bhaskar D. Univ Calif San Diego Dept Elect & Comp Engn La Jolla CA 92093 USA

This paper investigates the problem of transmit beamforming in multiple-antenna spatial multiplexing (SM) systems employing a finite-rate feedback channel. Assuming a fixed number of spatial channels and equal power allocation, we propose a new criterion for designing the codebook of beamforming matrices that is based on minimizing an approximation to the capacity loss resulting from the limited rate in the feedback channel. Using the criterion, we develop an iterative design algorithm that converges to a locally optimum codebook. Under the independent identically distributed channel and high signal-to-noise ratio (SNR) assumption, the effect on channel capacity of the finite-bit representation of the beamforming matrix is analyzed. Central to this analysis is the complex multivariate beta distribution and tractable approximations to the Voronoi regions associated with the code points. Furthermore, to compensate for the degradation due to the equal power allocation assumption, we propose a multimode SM transmission strategy wherein the number of data streams is determined based on the average SNR. This approach is shown to allow for effective utilization of the feedback bits resulting in a practical and efficient multiple-input multiple-output system design.

关键词： channel capacity channel information feedback matrix quantization multiple antennas multiple-input multiple-output (NUMO) systems spatial multiplexing transmit beamforming

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Limited Feedback Design for Interference Alignment on Two-Cell Interfering MIMO-MAC

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2015年第9期64卷 4019-4030页

作者： Kim, Myeong-Jin Lee, Hyun-Ho Ko, Young-Chai Korea Univ Sch Elect Engn Seoul 136713 South Korea LG Elect Adv Commun Technol Lab Seoul 137893 South Korea

This paper considers limited feedback for a two-cell interfering multiple-input-multiple-output multiple-access channel (MIMO-MAC). We propose a QR decomposition-based interference alignment (QRD-IA) scheme for efficient limited feedback and investigate the conditions for the antenna configuration. We characterize the interference leakage caused by quantization error as a function of the number of feedback bits. Tominimize the interference leakage, we further propose a quantized-precoder-based IA (QP-IA) scheme by modifying the proposed QRD-IA scheme. By characterizing the interference leakage of the QP-IA scheme, we investigate the number of feedback bits to maintain the degrees of freedom (DOFs) in the two-cell interfering MIMO-MAC and a feedback bit allocation algorithm to improve the sum rate. From simulation results, we demonstrate that our proposed schemes can provide better sum-rate performance than the existing scheme using the same number of feedback bits, and our feedback bit allocation algorithm provides a higher sum rate compared with equal feedback bit allocation.

关键词： Feedback bits allocation interference alignment (IA) limited feedback matrix quantization two-cell interfering multiple-input-multiple-output multiple-access channel (MIMO-MAC)

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Channel feedback quantization for high data rate MIMO systems

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2006年第12期5卷 3335-3338页

作者： Sadrabadi, Mehdi Ansari Khandani, Amir K. Lahouti, Farshad Univ Tehran Dept Elect & Comp Engn Tehran Iran

In this work, we study a multiple-input multiple-output (MIMO) wireless system where the channel state information is partially available at the transmitter through a feedback link. Based on singular value decomposition, the MIMO channel is split into independent sub-channels. Effective feedback of the required spatial channel information entails efficient quantization/encoding of a unitary matrix. We propose two schemes for quantizing unitary matrices via Givens rotations and examine the performance for a scenario where the rates allocated to the sub-channels are selected according to their corresponding gains. Numerical results show that the proposed schemes offer a significant performance improvement as compared to that of MIMO systems without feedback, with a negligible increase in the complexity.

关键词： MIMO wireless systems singular value decomposition Givens decomposition matrix quantization

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Filter Design of Interference Alignment Scheme with Limited Feedback for Two-Cell Interfering MIMO-MAC

Filter Design of Interference Alignment Scheme with Limited ...

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IEEE 24th International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)

作者： Kim, Myeong-Jin Ko, Young-Chai Lee, Hyun-Ho Korea Univ Sch Elect Engn Seoul South Korea LG Elect Adv Commun Technol Lab Seoul South Korea

ISBN: (纸本)9781467362351

In this paper, considering a two-cell interfering MIMO multiple access channel (MIMO-MAC), we propose an interference alignment scheme with an efficient limited feedback and investigate the conditions for the antenna configuration. In addition, we characterize the interference leakage power caused by quantization error as a function of feedback bits. From simulation results, we demonstrate that the proposed scheme can provide the better sum rate performance than the existing scheme under the same number of feedback bits.

关键词： Limited feedback matrix quantization interference alignment

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