Magdy Hanna | Fayoum University (original) (raw)

Papers by Magdy Hanna

IEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing, 1996

The design of linear phase FIR digital filters having symmetric or antisymmetric impulse response... more The design of linear phase FIR digital filters having symmetric or antisymmetric impulse response is formulated as a constrained minimization problem. The constraints express the maximal flatness of the frequency response at the origin in the case of a lowpass filter or at an arbitrary frequency in the passband in the case of a bandpass filter. The objective function , which is a quadratic form in the filter coefficients , is formed as a convex combination of two objective functions representing the energy of the error between the frequency response of the designed filter and a scaled version of the frequency response of the ideal filter in both the stop and pass bands.

IEEE Transactions on Signal Processing, 2003

A vector of digital filters is derived for the multichannel processing of the signals acquired by... more A vector of digital filters is derived for the multichannel processing of the signals acquired by an array of sensors with the objective of extracting multiple desired signals by the attenuation of multiple interferences and random noise. The signals and interferences are assumed to have arbitrary waveforms with no a priori knowledge of these waveforms. The time duration of the recorded array data is assumed to be long enough to incorporate all time delayed propagated waveforms at the sensors of the array. The derivation is for the general case of an arbitrary array geometric configuration and is not confined to the special case of a linear array of equispaced sensors. The rationale adopted in the derivation of the filters is to give first priority at each discrete frequency to passing the signals, a second priority to canceling the interferences and a third priority to attenuating the random noise. This rationale well suits the case of seismic data, that are dominantly corrupted by strong interferences rather than random noise. Solving a constrained minimization problem derives the vector of array filters. The computation of this vector requires the application of the powerful QR matrix decomposition technique for the detection of any redundant and/or inconsistent constraints at each discrete frequency. The simulation results demonstrate the extraction ability of the derived filters in both the multiple input single output and the multiple input multiple output processing schemes.

IEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing, 1996

A design technique is presented for two-dimensional linear phase lowpass FIR filters based on a c... more A design technique is presented for two-dimensional linear phase lowpass FIR filters based on a constrained minimization formulation. The minimization criterion is a convex combination of two criteria representing measures of the error between the actual and ideal frequency responses in the pass and stop bands. The constraints can for example represent flatness conditions at the origin. The result is applied to the case of a circularly symmetric lowpass filter and closed-form expressions are derived for the elements of the relevant matrices which appear in the minimization criterion so that numerical integration can be avoided.

2012 IEEE 55th International Midwest Symposium on Circuits and Systems (MWSCAS), 2012

IEEE Transactions on Acoustics, Speech, and Signal Processing

Array filters are derived for processing recorded measurements of an array of sensors in order to... more Array filters are derived for processing recorded measurements of an array of sensors in order to extract a desired signal buried in a background of interfering coherent and random noises. The intersensor travel times and relative amplitudes of the coherent noise and the statistics of the random noise are assumed to be known. The derivation of the filters is done in two steps. First, the family of array filters which best attenuate the coherent noise and satisfy an allpass requirement for the desired signal is characterized. Second, the unique member (of array filters) in this family which best attenuates the random noise is determined. These filters are best suited for applications (such as in seismic signal processing) where the coherent noise is predominant over the random noise and, consequently, its suppression is more important.

IEEE Transactions on Acoustics, Speech, and Signal Processing

Page 1. 844 IEEE TRANSACTIONS ON ACOUSTICS, SPEECH, AND SIGNAL PROCESSING. VOL. 36. NO. 6. JUNE 1... more Page 1. 844 IEEE TRANSACTIONS ON ACOUSTICS, SPEECH, AND SIGNAL PROCESSING. VOL. 36. NO. 6. JUNE 1988 Array Filters for Attenuating Multiple Coherent Interference Abstract-The problem of extracting a desired ...

Proceedings of IEEE International Symposium on Circuits and Systems - ISCAS '94, 2000

Abstract The design of a linear phase FIR filter is formulated as a constrained minimization prob... more Abstract The design of a linear phase FIR filter is formulated as a constrained minimization problem. The constraints express the maximally flat pass band frequency response requirement. The objective function is formed as a convex combination of two objective functions representing the energy of the error between the frequency responses of the desired and designed filters in both the stop and pass bands. This extends the results obtained where the mean squares error was minimized only over the stop band

Proceedings of IEEE International Symposium on Circuits and Systems - ISCAS '94, 2000

2005 Ieee International Symposium on Circuits and Systems, May 23, 2005

Page 1. Hermite-Gaussian-Like Eigenvectors of the DFT Matrix Generated by the Eigenanalysis of an... more Page 1. Hermite-Gaussian-Like Eigenvectors of the DFT Matrix Generated by the Eigenanalysis of an Almost Tridiagonal Matrix Magdy Tawfik Hanna Nabila Philip Attalla Seif Waleed Abd El Maguid Ahmed Department of Engineering ...

Tsp, 2008

The generation of Hermite-Gaussian-like orthonormal eigenvectors of the discrete Fourier transfor... more The generation of Hermite-Gaussian-like orthonormal eigenvectors of the discrete Fourier transform (DFT) matrix F is an essential step in the development of the discrete fractional Fourier transform (DFRFT). Most existing techniques depend on the generation of orthonormal eigenvectors of a nearly tridiagonal matrix S which commutes with matrix F. More sophisticated methods view the eigenvectors of S as only initial ones and use them for generating final ones which better approximate the Hermite-Gaussian functions employing a technique like the orthogonal procrustes algorithm (OPA). Here a direct technique for the collective (batch) evaluation of optimal Hermite-Gaussian-like eigenvectors of matrix F is contributed. It is a direct technique in the sense that it does not require the generation of initial eigenvectors to be used for computing the final superior ones. It is a batch method in the sense that it solves for the entire target modal matrix of F instead of the sequential generation of the eigenvectors. The simulation results show that the proposed method is faster than the OPA.

Seg Technical Program Expanded Abstracts, 1999

SEG Technical Program Expanded Abstracts 1984, 1984

Conclusions Seismic records from the Gulf of Mexico can be strongly contaminated by seismic inter... more Conclusions Seismic records from the Gulf of Mexico can be strongly contaminated by seismic interference if the time-sharing schedule for data acquisition is not observed by all the involved companies. The interfering energy exhibits linear noise patterns with a large range of moveouts. They can easily survive the stacking process. However, our newly developed technique (Silver) to suppress the high energy interfering noise, can be effectively used in the solution of this problem.

The 23rd IEEE Conference on Decision and Control, 1984

Abstract A special quadratic programming problem in complex variables is investigated for a close... more Abstract A special quadratic programming problem in complex variables is investigated for a closed form solution. Two different approaches are used. The first is a direct approach that leads to a family of solutions because of a singular matrix encountered in the solution process. The second is an indirect approach based on parametrizing the objective function. It leads to a solution which is a member in the above family and which is shown to be bounded.

ICASSP '85. IEEE International Conference on Acoustics, Speech, and Signal Processing, 1985

Abstract Array filters are derived for processing the measurements of an array of sensors in orde... more Abstract Array filters are derived for processing the measurements of an array of sensors in order to extract a signal buried in a background of coherent and random noise. The derivation is done in two steps. First, the family of array filters which achieve an all-pass condition for the signal and minimum array response to the coherent noise is derived. Second, the unique member in this family which minimizes the array output power spectrum in response to the random noise is determined.

ICASSP '87. IEEE International Conference on Acoustics, Speech, and Signal Processing, 1987

Abstract Digital filters are derived for the off-line processing of the recordings of an array of... more Abstract Digital filters are derived for the off-line processing of the recordings of an array of sensors in order to extract a desired signal corrupted by coherent interference. If the values of the amplitudes and delay times of the coherent interfering signal at the sensors are known exactly, the derived array filters achieve an all pass condition for the desired signal and minimum array response to the coherent interference. More importantly, if only estimates of the amplitudes and delay times are known, the derived array filters are minimally sensitive ...

2013 IEEE International Conference on Acoustics, Speech and Signal Processing, 2013

ABSTRACT The discrete fractional Fourier transform (DFRFT) depends heavily on the availability of... more ABSTRACT The discrete fractional Fourier transform (DFRFT) depends heavily on the availability of Hermite-Gaussian-like (HGL) orthonormal eigenvectors of the DFT matrix F. The direct batch evaluation by constrained optimization algorithm (DBEOA) was developed under the assumption that the orthogonal projection of the approximate eigenvectors on the corresponding eigenspaces results in linearly independent vectors. The present paper handles the case when those vectors are not linearly independent which happens when the order N of matrix F is large. A more general treatment of the batch generation of HGL eigenvectors is presented and the notion of matrix pseudoinverse is used for solving the linear system which arises in the solution of the constrained optimization problem. The contributed technique is termed the Direct Batch Evaluation by constrained Optimization Algorithm using the notion of matrix Pseudoinverse (DBEOAP). The simulation results show that the DBEOAP results in smaller values of the norms of the approximation error vectors than those obtained when applying the DBEOA.

2009 IEEE International Symposium on Circuits and Systems, 2009

Abstract The generation of orthonormal eigenvectors of a unitary matrix exemplified by the DFT ma... more Abstract The generation of orthonormal eigenvectors of a unitary matrix exemplified by the DFT matrix that are close to approximate desired eigenvectors-such as those formed by samples of the Hermite Gaussian functions-is formulated as a c. The unitarity of the matrix implies the orthogonality of its eigenspaces pertaining to its distinct eigenvalues and consequently orthonormal basis are sought for each eigenspace separately. The method advocated here is based on solving a series of constrained minimization problems where ...

2012 IEEE 55th International Midwest Symposium on Circuits and Systems (MWSCAS), 2012

Algorithm (RDBEOA) which is more numerically robust than the Abstract DBEOA. The reason behind th... more Algorithm (RDBEOA) which is more numerically robust than the Abstract DBEOA. The reason behind this numerical stability is that in the DBEOA the singular value decomposition (SVD) is applied to a ... A Revised and more numerically accurate version of the Direct ... (RDBEOA) of orthonormal eigenvectors of the DFT matrix F is presented. The superior numerical properties of the RDBEOA stem ... Let F be a unitary matrix of order N having distinct eigenvalues ... Algorithm (DBEOA). Having more accurate Hermite-Gaussian-like (HGL) orthonormal eigenvectors ...

2012 IEEE 55th International Midwest Symposium on Circuits and Systems (MWSCAS), 2012

Abstract Since having orthonormal Hermite-Gaussian-like eigenvectors of the DFT-IV matrix G is es... more Abstract Since having orthonormal Hermite-Gaussian-like eigenvectors of the DFT-IV matrix G is essential for developing a fractional discrete Fourier transform of type IV (FDFTIV), some methods for the generation of those eigenvectors are analyzed in a detailed simulation study involving evaluating the execution time, orthonormality error and approximation error. Since six of the nine methods included in the study necessitate knowledge of the orthogonal projection matrices on the eigenspaces of the DFT-IV matrix, explicit expressions are ...

2012 IEEE 55th International Midwest Symposium on Circuits and Systems (MWSCAS), 2012

Abstract 1-The fractional discrete Fourier transform of type matrix S which commutes with matrix ... more Abstract 1-The fractional discrete Fourier transform of type matrix S which commutes with matrix G. However he did IV (FDFT-IV) is a generalization of the discrete Fourier not treat the case of repeated eigenvalues of S where the transform of type IV (DFT-IV). The paper presents a fullycorresponding eigenvectors–as obtained by a general fledged definition for the FDFT-IV which necessitates the eigenanalysis procedure in any mathematical software availability of orthonormal eigenvectors of the DFT-IV matrix package–are not guaranteed ...

IEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing, 1996

The design of linear phase FIR digital filters having symmetric or antisymmetric impulse response... more The design of linear phase FIR digital filters having symmetric or antisymmetric impulse response is formulated as a constrained minimization problem. The constraints express the maximal flatness of the frequency response at the origin in the case of a lowpass filter or at an arbitrary frequency in the passband in the case of a bandpass filter. The objective function , which is a quadratic form in the filter coefficients , is formed as a convex combination of two objective functions representing the energy of the error between the frequency response of the designed filter and a scaled version of the frequency response of the ideal filter in both the stop and pass bands.

IEEE Transactions on Signal Processing, 2003

A vector of digital filters is derived for the multichannel processing of the signals acquired by... more A vector of digital filters is derived for the multichannel processing of the signals acquired by an array of sensors with the objective of extracting multiple desired signals by the attenuation of multiple interferences and random noise. The signals and interferences are assumed to have arbitrary waveforms with no a priori knowledge of these waveforms. The time duration of the recorded array data is assumed to be long enough to incorporate all time delayed propagated waveforms at the sensors of the array. The derivation is for the general case of an arbitrary array geometric configuration and is not confined to the special case of a linear array of equispaced sensors. The rationale adopted in the derivation of the filters is to give first priority at each discrete frequency to passing the signals, a second priority to canceling the interferences and a third priority to attenuating the random noise. This rationale well suits the case of seismic data, that are dominantly corrupted by strong interferences rather than random noise. Solving a constrained minimization problem derives the vector of array filters. The computation of this vector requires the application of the powerful QR matrix decomposition technique for the detection of any redundant and/or inconsistent constraints at each discrete frequency. The simulation results demonstrate the extraction ability of the derived filters in both the multiple input single output and the multiple input multiple output processing schemes.

IEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing, 1996

A design technique is presented for two-dimensional linear phase lowpass FIR filters based on a c... more A design technique is presented for two-dimensional linear phase lowpass FIR filters based on a constrained minimization formulation. The minimization criterion is a convex combination of two criteria representing measures of the error between the actual and ideal frequency responses in the pass and stop bands. The constraints can for example represent flatness conditions at the origin. The result is applied to the case of a circularly symmetric lowpass filter and closed-form expressions are derived for the elements of the relevant matrices which appear in the minimization criterion so that numerical integration can be avoided.

2012 IEEE 55th International Midwest Symposium on Circuits and Systems (MWSCAS), 2012

IEEE Transactions on Acoustics, Speech, and Signal Processing

Array filters are derived for processing recorded measurements of an array of sensors in order to... more Array filters are derived for processing recorded measurements of an array of sensors in order to extract a desired signal buried in a background of interfering coherent and random noises. The intersensor travel times and relative amplitudes of the coherent noise and the statistics of the random noise are assumed to be known. The derivation of the filters is done in two steps. First, the family of array filters which best attenuate the coherent noise and satisfy an allpass requirement for the desired signal is characterized. Second, the unique member (of array filters) in this family which best attenuates the random noise is determined. These filters are best suited for applications (such as in seismic signal processing) where the coherent noise is predominant over the random noise and, consequently, its suppression is more important.

IEEE Transactions on Acoustics, Speech, and Signal Processing

Page 1. 844 IEEE TRANSACTIONS ON ACOUSTICS, SPEECH, AND SIGNAL PROCESSING. VOL. 36. NO. 6. JUNE 1... more Page 1. 844 IEEE TRANSACTIONS ON ACOUSTICS, SPEECH, AND SIGNAL PROCESSING. VOL. 36. NO. 6. JUNE 1988 Array Filters for Attenuating Multiple Coherent Interference Abstract-The problem of extracting a desired ...

Proceedings of IEEE International Symposium on Circuits and Systems - ISCAS '94, 2000

Abstract The design of a linear phase FIR filter is formulated as a constrained minimization prob... more Abstract The design of a linear phase FIR filter is formulated as a constrained minimization problem. The constraints express the maximally flat pass band frequency response requirement. The objective function is formed as a convex combination of two objective functions representing the energy of the error between the frequency responses of the desired and designed filters in both the stop and pass bands. This extends the results obtained where the mean squares error was minimized only over the stop band

Proceedings of IEEE International Symposium on Circuits and Systems - ISCAS '94, 2000

2005 Ieee International Symposium on Circuits and Systems, May 23, 2005

Page 1. Hermite-Gaussian-Like Eigenvectors of the DFT Matrix Generated by the Eigenanalysis of an... more Page 1. Hermite-Gaussian-Like Eigenvectors of the DFT Matrix Generated by the Eigenanalysis of an Almost Tridiagonal Matrix Magdy Tawfik Hanna Nabila Philip Attalla Seif Waleed Abd El Maguid Ahmed Department of Engineering ...

Tsp, 2008

The generation of Hermite-Gaussian-like orthonormal eigenvectors of the discrete Fourier transfor... more The generation of Hermite-Gaussian-like orthonormal eigenvectors of the discrete Fourier transform (DFT) matrix F is an essential step in the development of the discrete fractional Fourier transform (DFRFT). Most existing techniques depend on the generation of orthonormal eigenvectors of a nearly tridiagonal matrix S which commutes with matrix F. More sophisticated methods view the eigenvectors of S as only initial ones and use them for generating final ones which better approximate the Hermite-Gaussian functions employing a technique like the orthogonal procrustes algorithm (OPA). Here a direct technique for the collective (batch) evaluation of optimal Hermite-Gaussian-like eigenvectors of matrix F is contributed. It is a direct technique in the sense that it does not require the generation of initial eigenvectors to be used for computing the final superior ones. It is a batch method in the sense that it solves for the entire target modal matrix of F instead of the sequential generation of the eigenvectors. The simulation results show that the proposed method is faster than the OPA.

Seg Technical Program Expanded Abstracts, 1999

SEG Technical Program Expanded Abstracts 1984, 1984

Conclusions Seismic records from the Gulf of Mexico can be strongly contaminated by seismic inter... more Conclusions Seismic records from the Gulf of Mexico can be strongly contaminated by seismic interference if the time-sharing schedule for data acquisition is not observed by all the involved companies. The interfering energy exhibits linear noise patterns with a large range of moveouts. They can easily survive the stacking process. However, our newly developed technique (Silver) to suppress the high energy interfering noise, can be effectively used in the solution of this problem.

The 23rd IEEE Conference on Decision and Control, 1984

Abstract A special quadratic programming problem in complex variables is investigated for a close... more Abstract A special quadratic programming problem in complex variables is investigated for a closed form solution. Two different approaches are used. The first is a direct approach that leads to a family of solutions because of a singular matrix encountered in the solution process. The second is an indirect approach based on parametrizing the objective function. It leads to a solution which is a member in the above family and which is shown to be bounded.

ICASSP '85. IEEE International Conference on Acoustics, Speech, and Signal Processing, 1985

Abstract Array filters are derived for processing the measurements of an array of sensors in orde... more Abstract Array filters are derived for processing the measurements of an array of sensors in order to extract a signal buried in a background of coherent and random noise. The derivation is done in two steps. First, the family of array filters which achieve an all-pass condition for the signal and minimum array response to the coherent noise is derived. Second, the unique member in this family which minimizes the array output power spectrum in response to the random noise is determined.

ICASSP '87. IEEE International Conference on Acoustics, Speech, and Signal Processing, 1987

Abstract Digital filters are derived for the off-line processing of the recordings of an array of... more Abstract Digital filters are derived for the off-line processing of the recordings of an array of sensors in order to extract a desired signal corrupted by coherent interference. If the values of the amplitudes and delay times of the coherent interfering signal at the sensors are known exactly, the derived array filters achieve an all pass condition for the desired signal and minimum array response to the coherent interference. More importantly, if only estimates of the amplitudes and delay times are known, the derived array filters are minimally sensitive ...

2013 IEEE International Conference on Acoustics, Speech and Signal Processing, 2013

ABSTRACT The discrete fractional Fourier transform (DFRFT) depends heavily on the availability of... more ABSTRACT The discrete fractional Fourier transform (DFRFT) depends heavily on the availability of Hermite-Gaussian-like (HGL) orthonormal eigenvectors of the DFT matrix F. The direct batch evaluation by constrained optimization algorithm (DBEOA) was developed under the assumption that the orthogonal projection of the approximate eigenvectors on the corresponding eigenspaces results in linearly independent vectors. The present paper handles the case when those vectors are not linearly independent which happens when the order N of matrix F is large. A more general treatment of the batch generation of HGL eigenvectors is presented and the notion of matrix pseudoinverse is used for solving the linear system which arises in the solution of the constrained optimization problem. The contributed technique is termed the Direct Batch Evaluation by constrained Optimization Algorithm using the notion of matrix Pseudoinverse (DBEOAP). The simulation results show that the DBEOAP results in smaller values of the norms of the approximation error vectors than those obtained when applying the DBEOA.

2009 IEEE International Symposium on Circuits and Systems, 2009

Abstract The generation of orthonormal eigenvectors of a unitary matrix exemplified by the DFT ma... more Abstract The generation of orthonormal eigenvectors of a unitary matrix exemplified by the DFT matrix that are close to approximate desired eigenvectors-such as those formed by samples of the Hermite Gaussian functions-is formulated as a c. The unitarity of the matrix implies the orthogonality of its eigenspaces pertaining to its distinct eigenvalues and consequently orthonormal basis are sought for each eigenspace separately. The method advocated here is based on solving a series of constrained minimization problems where ...

2012 IEEE 55th International Midwest Symposium on Circuits and Systems (MWSCAS), 2012

Algorithm (RDBEOA) which is more numerically robust than the Abstract DBEOA. The reason behind th... more Algorithm (RDBEOA) which is more numerically robust than the Abstract DBEOA. The reason behind this numerical stability is that in the DBEOA the singular value decomposition (SVD) is applied to a ... A Revised and more numerically accurate version of the Direct ... (RDBEOA) of orthonormal eigenvectors of the DFT matrix F is presented. The superior numerical properties of the RDBEOA stem ... Let F be a unitary matrix of order N having distinct eigenvalues ... Algorithm (DBEOA). Having more accurate Hermite-Gaussian-like (HGL) orthonormal eigenvectors ...

2012 IEEE 55th International Midwest Symposium on Circuits and Systems (MWSCAS), 2012

Abstract Since having orthonormal Hermite-Gaussian-like eigenvectors of the DFT-IV matrix G is es... more Abstract Since having orthonormal Hermite-Gaussian-like eigenvectors of the DFT-IV matrix G is essential for developing a fractional discrete Fourier transform of type IV (FDFTIV), some methods for the generation of those eigenvectors are analyzed in a detailed simulation study involving evaluating the execution time, orthonormality error and approximation error. Since six of the nine methods included in the study necessitate knowledge of the orthogonal projection matrices on the eigenspaces of the DFT-IV matrix, explicit expressions are ...

2012 IEEE 55th International Midwest Symposium on Circuits and Systems (MWSCAS), 2012

Abstract 1-The fractional discrete Fourier transform of type matrix S which commutes with matrix ... more Abstract 1-The fractional discrete Fourier transform of type matrix S which commutes with matrix G. However he did IV (FDFT-IV) is a generalization of the discrete Fourier not treat the case of repeated eigenvalues of S where the transform of type IV (DFT-IV). The paper presents a fullycorresponding eigenvectors–as obtained by a general fledged definition for the FDFT-IV which necessitates the eigenanalysis procedure in any mathematical software availability of orthonormal eigenvectors of the DFT-IV matrix package–are not guaranteed ...