In this paper, we have proposed a new steering direction determination mechanism and step-size update algorithm for piloted adaptive notch filter architecture. A timedomain averaging based gradient analysis of the piloted notch cost function has been utilized to determine the direction of the main notch with respect to the input sinusoid frequency. The steering direction will indicate the distance between the frequency of the input sinusoid and the zero of the main notch. This frequency domain information has been interleaved with time domain information to develop a novel algorithm for determination of variable step-sizes for improved speed of convergence with comparatively huge reduction in steady-state mean square error (MSE). The simulation results verifies the excellent performance exhibited by our proposed steering mechanism and the step-size update algorithm over original piloted adaptive notch filter with respect to the speed of convergence and MSE.

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A piloted notch time-frequency information based variable step-size algorithm

In this paper, we have presented a multi-piloted notch filter structure with the generalized formulation for introduction of more number of pilots to the original piloted notch filter having an option for a range of step-size values. The structure of multi-piloted notch filter has been studied through simulations to make it more adaptive by using multiple step-size values. Thus, the transition from a very large step-size value to a very small step-size value has been smoothed using intermediate values of step-size such that the main notch does not cross-over the frequency of input sinusoid with larger error when it is very close to it. Moreover, this has been useful in selecting a larger step-size value when the notch is away from the input frequency to increase the rate of convergence. The simulation results verify the excellent performance exhibited by multi-piloted notch filter over the original piloted notch filter with respect to the speed of convergence and mean square error (MSE).

A multi-piloted notch filter for frequency estimation and tracking

Tracking of real and complex sinusoids using piloted adaptive notch filter

This paper aims to propose a noble method to estimate the auto-regressive(AR) coefficients used by least-square(LS) based predictors. Estimation of this LS based predictors is computationally most complex process. This process requires a covariance matrix comprised of chosen causal pixels and also the inverse elements of the same matrix. Computational requirements of this process depends on the number of pixels for which the predictor is trained and also on the order of the predictor. Due to this high complexity, the predictor is not used practically although it provides a high compression ratio. Thus, an alternative algorithm, popularly known as LOPT-3D, was proposed in literature. However, the number of pixels required for the estimation of AR parameters are still large, and thereby, making it impracticable for real-time implementations. The proposed method overcomes this limitation by effectively making use of previously estimated AR parameters.

Temporal Stationarity Based Prediction Method For Lossless Video Coding

This paper proposes a new adaptive algorithm for gradient based adaptive notch filter in order to improve the convergence speed. We develop a new gradient by combining the gradients of two notch filters with the different rejection bandwidth. We also develop a variable step-size on the basis of the difference of the impulse response between two notch filters. Through the experiment, we reveal the effectiveness of the proposed method.

Design of Gradient and Variable Step-Size for Fast Adaptive Notch Filter

In this paper, we have presented the performance comparison of the piloted adaptive notch filter with the second- order adaptive IIR lattice notch filter and the adaptive IIR notch filter with constrained poles and zeroes. The steady-state analysis for mean square error (MSE) of the frequency estimate using simulations has been provided with roles of the user variables such as notch bandwidth and signal to noise ratio (SNR). This study verifies the excellent performance exhibited by the piloted adaptive notch filter over other algorithms with respect to the speed of convergence and MSE. Extensive computer simulations have been done to study the performance over a wide range of SNR and frequency values. I. INTRODUCTION In digital signal processing, frequency estimation and track- ing of sinusoids in noise has been an important area of research to solve problems in radar, communications, bio-medical and other related areas. Extensive research has been carried out in designing and analysis of both finite-impulse response (FIR) type adaptive filters and infinite-impulse response (IIR) type adaptive filters to estimate and track the frequency of input sinusoid being corrupted with noise. The FIR based adaptive line enhancer (ALE), though the simplest solution to the problem, has relatively slow rate of convergence and is highly responsive to the autocorrelation of the input signal. It requires a relatively larger number of filter coefficients as compared to the IIR based ALE for the same narrow bandwidth notch to reject the interfering noise. Thus, there have been efforts to improve the performance of adaptive IIR notch filters and various novel filter structures have been proposed in literature.

Steady-State Comparative Performance Evaluation of Piloted Adaptive Notch Filter

In this work, we propose a method of lossless video coding which not has only the decoder simple but encoder is also simple, unlike other reported methods which has computationally complex encoder. The computation is mainly due to not using motion compensation method, which is computationally complex process. The coefficient of the predictors are obtained based on an averaging process and then the thus obtained set of switched predictors is used for prediction. The parameters have been obtained after undergoing a statistical process of averaging so that proper relationship can be established between the predicted pixel and their context.

Dinesh Kumar Chobey

Papers

Steady-State Comparative Performance Evaluation of Piloted Adaptive Notch Filter

A piloted notch time-frequency information based variable step-size algorithm

A multi-piloted notch filter for frequency estimation and tracking

An Optimal Switched Adaptive Prediction Method for Lossless Video Coding

Temporal Stationarity Based Prediction Method For Lossless Video Coding