2002 14th International Conference on Digital Signal Processing Proceedings. DSP 2002 (Cat. No.02TH8628)
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Các bài báo tiêu biểu
Improving the speed and performance of adaptive equalizers via transform based adaptive filtering
Tập 2 - Trang 1301-1304 vol.2
Adaptive equalizers are widely used in many communication systems where the
channel frequency response characteristics are either time varying or unknown
such as the case in wireless and dial up telecommunication networks where the
communication channel constantly change due to the different packet routes and
switching that takes place, as well as due to the changes in the RF propagation.
This wor...
#Adaptive equalizers #Adaptive filters #Discrete Fourier transforms #Discrete wavelet transforms #Fourier transforms #Discrete cosine transforms #Eigenvalues and eigenfunctions #Frequency response #Time varying systems #Communication channels
Recursive non parametric spectral estimation from irregularly sampled observations
Tập 2 - Trang 799-802 vol.2
In this paper, the nonparametric spectral analysis of a randomly sampled signal
is discussed. In particular, a class of estimators is introduced: the IRINCORREL
class. This class is composed of recursive algorithms which both take into
account the sampling irregularity and the correlation of the signal values. The
study of the mean square estimation error shows that there is a trade off
between bi...
#Recursive estimation #Sampling methods #Spectral analysis #Signal processing algorithms #Frequency #Random variables #Large Hadron Collider #Estimation error #Convergence #Signal processing
Watermark technique using frequency domain
Tập 2 - Trang 729-731 vol.2
Watermarking is a commonly used technique to hide information in images to
discourage unauthorized copying. One of the important issues of watermarking is
the robustness subject to lossy compression of the watermarked image. In this
paper, a technique of hiding the watermark in the middle frequency portion of
the original image is proposed. The modification of the mid-frequency
coefficients corres...
#Watermarking #Frequency domain analysis #Image coding #Robustness #Transform coding #Quantization #Indexing #Trademarks #Information security #Data mining
Limit cycles in embedded high-order, lowpass sigma-delta modulators with distinct NTF zeros
Tập 2 - Trang 1043-1047 vol.2
In a related work by the authors, high-order sigma-delta (/spl Sigma//spl
Delta/) modulators with distinct noise transfer function (NTF) zeros are
decomposed into second-order and first-order subsystems, whose
state-trajectories are then investigated by continuous-time embedding. This
paper, based on the properties of these subsystems, furthers the study by
introducing a scalable numerical method ...
#Limit-cycles #Delta-sigma modulation #Stability #Transfer functions #Matrix decomposition #Nonlinear equations #State feedback #Digital signal processing
An adaptive combination of adaptive filters for plant identification
Tập 2 - Trang 1195-1198 vol.2
In this paper, we propose to adaptively combine two LMS adaptive transversal
filters for plant identification. One of the filters has a high and the other a
low adaption step, in order to combine good tracking capabilities under (fast)
change conditions with a reduced convergence error along stationary periods. A
brief discussion of the characteristics of the combination is included,
emphasizing t...
#Adaptive filters #Least squares approximation #Transversal filters #Convergence #System identification #Steady-state #Signal processing #Filtering algorithms #Robustness #Teleprinting
Time-varying allpass filters using spectral-shaped noise for signal decorrelation in stereophonic acoustic echo cancellation
Tập 2 - Trang 1273-1276 vol.2
In this paper, a signal decorrelation technique is presented that aims to
minimise the degradation on stereo signal perception, whilst alleviating the
non-uniqueness problem in stereophonic acoustic echo cancellation (SAEC). The
proposed technique is based on higher-order time-varying allpass filters
(HO-TV-APF) utilising spectral-shaped noise, together with the interpolation
method. The test resu...
#Decorrelation #Frequency #Delay #Signal processing #Acoustic noise #Adaptive filters #Equations #Computational complexity #Low-frequency noise #Baseband
Automatic detection and recognition of hazardous chemical agents
Tập 2 - Trang 1345-1348 vol.2
The number and use of hazardous chemical compounds are increasing, providing an
important and critical application area of detector devices. In addition to the
devices, also extremely reliable detection algorithms must be implemented. The
design of such algorithms has traditionally been an analytical process demanding
a vast amount of work and expertise. Thus, there is a strong interest of
automat...
#Chemical hazards #Learning systems #Detectors #Chemical sensors #Chemical compounds #Spectroscopy #Electrodes #Chemical technology #Algorithm design and analysis #Robust stability
Relationship between sampling rate and quantization noise
Tập 2 - Trang 807-810 vol.2
Few works have been done about the dependency of the quantization noise with the
sampling rate for uniform quantizers. Some of these works have considered the
problem from a deterministic point of view while others study it from a
stochastic one, having explained the noise behavior in some specific cases. By
using computer simulations with a sinusoidal input signal, we show that the
quantization n...
#Sampling methods #Quantization #Stochastic resonance #Frequency #White noise #Additive white noise #Computer simulation #Signal to noise ratio #Pulse modulation #Distortion
Stochastic approximation and data re-use applied to blind adaptive algorithm for interference cancellation RAKE CDMA receiver
Tập 2 - Trang 639-642 vol.2
This paper addresses the problem of stochastic approximation and data re-use
applied to the blind adaptive algorithm for the interference cancellation RAKE
CDMA receiver. The improved adaptive algorithm that utilizes step-size
adaptation can achieve both faster convergence and higher steady state
performance compared to the fixed step-size ones without increasing much more
complexity. Moreover, th...
#Stochastic processes #Adaptive algorithm #Interference cancellation #RAKE receivers #Multiaccess communication #Steady-state #Signal processing algorithms #Training data #Convergence #Interference suppression
A scheduling scheme for multiplexing extra streaming data into digital TV programs
Tập 2 - Trang 579-582 vol.2
In digital TV systems, variable bitrate encoding is usually used to improve the
bandwidth usage efficiency. Since the transmission channel has a fixed
bandwidth, this leaves some portions of the bandwidth unoccupied. This free
space can be used to transmit extra data to enhance the TV content, which can be
either discrete, like text, or streaming, like video and audio. We address the
problem of ad...
#Digital TV #Streaming media #Bandwidth #Scheduling algorithm #Decoding #Delay #Bit rate #Processor scheduling #TV receivers #Quality of service