A novel noise power spectral density (PSD) estimator for disturbed speech signals which operates in the short-time Fourier domain is presented. A noise PSD estimate is provided by constrained tracing with time of the ...
详细信息
In UMTS speech transmissions, the Adaptive Multi-Rate (AMR) speech codec is employed to allow for a dynamic assignment of data rates to individual users. The control of AMR modes is based on quality measurements of th...
详细信息
In UMTS speech transmissions, the Adaptive Multi-Rate (AMR) speech codec is employed to allow for a dynamic assignment of data rates to individual users. The control of AMR modes is based on quality measurements of the transmission channel and aims at the maximization of speech quality by selecting the mode which is best suited to the current interference situation. In contrast to GSM, a reduction of AMR modes also leads to an increased cell capacity in UMTS. In this paper, a decentralized method for AMR mode switching is presented which is based on individual softbit measurements at the Viterbi channel decoder and optimizes the speech quality for a wide range of channel conditions. This method was developed by optimizing the AMR mode switching thresholds with respect to PESQ speech quality scores. The second part of the paper describes a new instrumental non-intrusive method for speech quality measurement by the evaluation of UMTS transmission parameters for application to UMTS-AMR speech transmissions. High correlations with the reference PESQ scores were observed.
Methods for measuring the impulse response of a linear transmission system and system identification algorithms in general must be robust against noise in the measured system response. To handle the noise it is of gre...
详细信息
Linear transmission systems are often characterized by their impulse responses. A simple and fast approach to acquire these impulse responses is the normalized leastmean- square (NLMS) algorithm in combination with a ...
详细信息
We present a methodology to optimize the system parameterization for speech and audio transmission in heterogeneous packet networks with wireless access. To this end, we determine the theoretical performance of forwar...
详细信息
Signal processing algorithms for near end listening enhancement allow to improve the intelligibility of clean (far end) speech for the near end listener who perceives not only the far end speech but also ambient backg...
详细信息
In this contribution we investigate the influence of audio coding on beamforming algorithms. Usually, a beamforming system would be implemented in the same device as the microphones. However, for some devices such as ...
详细信息
A new criterion is derived for the design of the noise weighting filter in linear predictive coding (LPC) that accounts for the issue of noise propagation. It will be shown that the new filter design constitutes an ap...
详细信息
In this paper a novel type of gain-shape vector quantization (GSVQ) is presented, denoted as Logarithmic Cubic Vector Quantization (LCVQ). LCVQ is based on a decomposition of the vector to be quantized into a gain fac...
详细信息
This contribution presents a novel speech enhancement algorithm for the suppression of background noise and late reverberation without a priori knowledge. The speech enhancement is performed by a generalized spectral ...
详细信息
暂无评论