Adnan Hanif | The George Washington University (original) (raw)

Papers by Adnan Hanif

2023 IEEE Pulsed Power Conference (PPC)

The Imaging Science Journal, Jul 1, 2013

Single-photon emission computerised tomography (SPECT) and positron emission tomography (PET) are... more Single-photon emission computerised tomography (SPECT) and positron emission tomography (PET) are essential medical imaging tools, with inherent drawback of slow data acquisition process. We present a novel compressed sensing-based reconstruction of these images from significantly fewer measurements than traditionally required, thus demonstrating potential of reduction in scan time and radiopharmaceutical doze with benefits for patients and health care economics. Our work effectively shows that high fidelity two-dimensional (2D) SPECT/PET image is reconstructed using compressive sensing with considerably reduced numbers of samples in acquisition stage. The reconstruction of tomographic images is realised by compressed sensing the 2D Fourier projections of k-space data. These 2D projections being sparse in transform domain need fewer samples in k-space and are reconstructed without loss of fidelity. These undersampled Fourier projections can then be backprojected by employing the iterative reconstruction approach for a complete three-dimensional (3D) volume. Compressed sensing of a phantom image and PET bone scintigraphy with radial Fourier samples are performed. The reconstructions of these images are compared to conventionally sampled images using image quality measures like mean square error, peak signal-to-noise ratio and structure similarity (SSIM) index, showing high-quality image reconstruction.

The broad spectrum available in Terahertz (THz) band is envisaged to simultaneously meet both dat... more The broad spectrum available in Terahertz (THz) band is envisaged to simultaneously meet both data and energy demands of the next-generation battery-limited wireless devices. Recent advances in THz semiconductor technologies and antenna design are closing the gap in low-powered millimeter-scale receiver architectures. Consequently, prospective signal processing and modulation schemes are emerging for base-station transmission to achieve efficient power and high-rate information transfer to an integrated receiver (IntRx). In this paper, we present for the first time an on-off keying (OOK) power modulation scheme for simultaneous THz information and power transfer (STIPT) to an IntRx involving a THz diode-based rectenna demodulator. A novel non-linear rectenna model is first proposed which provides a theoretical upper bound to harvested DC power. By leveraging the convexity of harvested DC power to incoming single-carrier signal power, an OOK power modulation scheme is then designed to maximize power transfer under available input power constraints. Lastly, both theoretical and simulation results involving a THz band GaAs Schottky diode demonstrate that the proposed scheme maximizes power transfer while simultaneously maintaining Gbps data rate and nanosecond latency communication.

IEEE Journal of Selected Topics in Signal Processing, 2023

Terahertz (THz) band transmission has the potential to revolutionize future-generation wireless n... more Terahertz (THz) band transmission has the potential to revolutionize future-generation wireless networks by jointly meeting communication and non-communication demands of their connected devices. Recent advances in THz semiconductor technologies and antenna design are closing the THz band gap in millimeter-scale devices which are often battery-limited. The localization of these mobile devices in future wireless networks is of paramount significance for beamforming to overcome THz propagation loss. Consequently, prospective signal processing techniques with co-design architectures are emerging either for joint communication and sensing or for simultaneous information and power transfer. In this paper, we present a novel approach toward Simultaneous Terahertz Imaging with Information and Power Transfer (STIIPT) from a base station transceiver to an Integrated Receiver (IntRx). Leveraging the proposed non-linear rectenna model for energy harvesting, a customized On-Off Keying (cOOK) modulation scheme is proposed for simultaneous communication through a non-linear THz channel while generating a radar-like image to localize the IntRx acting as a target. The proposed theoretical models are corroborated with simulations using a THz band GaAs Schottky diode to demonstrate STIIPT performances which also emphasize the significance of ranging information to optimize rate–energy transfer tradeoff under the cOOK modulation scheme. THz band, 6G, non-linear model, rectenna, IntRx, customized OOK modulation, 2D radar imaging, STIIPT

2022 30th European Signal Processing Conference (EUSIPCO), Aug 29, 2022

Simultaneous wireless information and power transfer (SWIPT) has the potential to realize the env... more Simultaneous wireless information and power transfer (SWIPT) has the potential to realize the envisioned ubiquity of the internet of things (IoT) by energizing them wirelessly whilst exchanging information. Recently, low-complexity receiver architectures for SWIPT are being considered for decoding information from amplitude modulated signals after rectification. However, less attention is paid towards improving the non-linear rectifier model prevalent in these architectures which is often truncated till fourth-order term in diode characteristic. In this paper, a novel, tractable analytical model for the rectenna non-linearity is presented which provides a theoretical upper bound to harvested DC power over the amplitude shift keying (ASK) constellation space corresponding to the entire diode non-linear region. Besides, the work also exposes the convexity of harvested DC power vis-à-vis incoming signal power thereby verifying the rate-energy (R-E) tradeoff in SWIPT for different choices of transmitted symbol amplitude distributions. Finally, the theoretical results presented using the adopted model are substantiated with the Monte Carlo circuit simulations allowing to conveniently evaluate and draw compromise in SWIPT performance against a choice of modulation scheme out of the ASK constellation space.

Brain tumor segmentation in Magnetic Resonance Imaging (MRI) scans provides vital information to ... more Brain tumor segmentation in Magnetic Resonance Imaging (MRI) scans provides vital information to radiologists in the diagnosis and staging of disease. However, these MRI scans are often corrupted with noise during its acquisition. Traditional approaches to this problem employ denoising which leads, in general, to edge smoothing and development of artifacts in MRI slices, thereby affecting tumor segmentation performance. In this paper, we employed graph signal processing (GSP) theory to first segment tumor core in each MRI slice using graph Laplacian followed by edge-aware denoising which is performed in synergy. The paper aims to present a novel technique to tackle the two problems of segmentation and denoising both under the GSP framework. The experimental results demonstrated on simulated and clinical brain MRI datasets, show highly competitive performance both in terms of tumor core segmentation under Dice and Sensitivity measures, and in terms of edge-aware denoising under PSNR and SSIM measures.

2023 IEEE Wireless Power Technology Conference and Expo (WPTCE)

A breakthrough in the 6G wireless network is imminent with the employment of Terahertz (THz) band... more A breakthrough in the 6G wireless network is imminent with the employment of Terahertz (THz) band transmission to meet both the information and energy demands of their connected devices simultaneously. Inspired by the advances in the THz neighboring bands, a novel non-linear model of an intensity-modulation and direct-detection (IM/DD) is proposed to perform simultaneous THz information and power transfer (STIPT) over a 6G point-to-point link. We present a non-truncated yet tractable analytical diode model of a rectenna-based DD receiver and find an upper bound for the harvested DC power over an IM transmission. Besides, the simultaneous achievable information rate is evaluated for a power-maximizing input traveling through a distance-dependent THz channel. The theoretical model is supported with simulations involving both ideal and real THz GaAs Schottky diode parameters to assess STIPT performance. The results demonstrate that by employing an on-off keying (OOK) scheme in the IM/DD model, a 6G network of battery-less devices can be extended up to several meters while communicating at a Gbps data rate.

... Adnan Hanif a, Atif Bin Mansoor a, Tahira Ejaz b ... 23, April 2004. [11] Zhou Wang, Alan C. ... more ... Adnan Hanif a, Atif Bin Mansoor a, Tahira Ejaz b ... 23, April 2004. [11] Zhou Wang, Alan C. Bovik,Hamid R. Sheikh, and Eero P. Simoncelli, “Image quality assessment: From error measurement to structural similarity,” IEEE Trans-actions on Image Processing, vol. ...

IEEE Wireless Power Technology Conference and Expo (WPTCE), 2023

A breakthrough in the 6G wireless network is imminent with the employment of Terahertz (THz) band... more A breakthrough in the 6G wireless network is imminent with the employment of Terahertz (THz) band transmission to meet both the information and energy demands of their connected devices simultaneously. Inspired by the advances in the THz neighboring bands, a novel non-linear model of an intensity-modulation and direct-detection (IM/DD) is proposed to perform simultaneous THz information and power transfer (STIPT) over a 6G point-to-point link. We present a non-truncated yet tractable analytical diode model of a rectenna-based DD receiver and find an upper bound for the harvested DC power over an IM transmission. Besides, the simultaneous achievable information rate is evaluated for a power-maximizing input traveling through a distance-dependent THz channel. The theoretical model is supported with simulations involving both ideal and real THz GaAs Schottky diode parameters to assess STIPT performance. The results demonstrate that by employing an on-off keying (OOK) scheme in the IM/DD model, a 6G network of battery-less devices can be extended up to several meters while communicating at a Gbps data rate.

IEEE Journal of Selected Topics in Signal Processing

Terahertz (THz) band transmission has the potential to revolutionize future-generation wireless n... more Terahertz (THz) band transmission has the potential to revolutionize future-generation wireless networks by jointly meeting communication and non-communication demands of their connected devices. Recent advances in THz semiconductor technologies and antenna design are closing the THz band gap in millimeter-scale devices which are often battery-limited. The localization of these mobile devices in future wireless networks is of paramount significance for beamforming to overcome THz propagation loss. Consequently, prospective signal processing techniques with co-design architectures are emerging either for joint communication and sensing or for simultaneous information and power transfer. In this paper, we present a novel approach toward Simultaneous Terahertz Imaging with Information and Power Transfer (STIIPT) from a base station transceiver to an Integrated Receiver (IntRx). Leveraging the proposed non-linear rectenna model for energy harvesting, a customized On-Off Keying (cOOK) modulation scheme is proposed for simultaneous communication through a non-linear THz channel while generating a radar-like image to localize the IntRx acting as a target. The proposed theoretical models are corroborated with simulations using a THz band GaAs Schottky diode to demonstrate STIIPT performances which also emphasize the significance of ranging information to optimize rate–energy transfer tradeoff under the cOOK modulation scheme. THz band, 6G, non-linear model, rectenna, IntRx, customized OOK modulation, 2D radar imaging, STIIPT

IEEE Journal of Selected Topics in Signal Processing, 2023

Terahertz (THz) band transmission has the potential to revolutionize future-generation wireless n... more Terahertz (THz) band transmission has the potential to revolutionize future-generation wireless networks by jointly meeting communication and non-communication demands of their connected devices. Recent advances in THz semiconductor technologies and antenna design are closing the THz band gap in millimeter-scale devices which are often battery-limited. The localization of these mobile devices in future wireless networks is of paramount significance for beamforming to overcome THz propagation loss. Consequently, prospective signal processing techniques with co-design architectures are emerging either for joint communication and sensing or for simultaneous information and power transfer. In this paper, we present a novel approach toward Simultaneous Terahertz Imaging with Information and Power Transfer (STIIPT) from a base station transceiver to an Integrated Receiver (IntRx). Leveraging the proposed non-linear rectenna model for energy harvesting, a customized On-Off Keying (cOOK) modulation scheme is proposed for simultaneous communication through a non-linear THz channel while generating a radar-like image to localize the IntRx acting as a target. The proposed theoretical models are corroborated with simulations using a THz band GaAs Schottky diode to demonstrate STIIPT performances which also emphasize the significance of ranging information to optimize rate–energy transfer tradeoff under the cOOK modulation scheme.
THz band, 6G, non-linear model, rectenna, IntRx, customized OOK modulation, 2D radar imaging, STIIPT

2022 56th Asilomar Conference on Signals, Systems, and Computers, 2022

The broad spectrum available in Terahertz (THz) band is envisaged to simultaneously meet both dat... more The broad spectrum available in Terahertz (THz) band is envisaged to simultaneously meet both data and energy demands of the next-generation battery-limited wireless devices. Recent advances in THz semiconductor technologies and antenna design are closing the gap in low-powered millimeter-scale receiver architectures. Consequently, prospective signal processing and modulation schemes are emerging for base-station transmission to achieve efficient power and high-rate information transfer to an integrated receiver (IntRx). In this paper, we present for the first time an on-off keying (OOK) power modulation scheme for simultaneous THz information and power transfer (STIPT) to an IntRx involving a THz diode-based rectenna demodulator. A novel non-linear rectenna model is first proposed which provides a theoretical upper bound to harvested DC power. By leveraging the convexity of harvested DC power to incoming single-carrier signal power, an OOK power modulation scheme is then designed to maximize power transfer under available input power constraints. Lastly, both theoretical and simulation results involving a THz band GaAs Schottky diode demonstrate that the proposed scheme maximizes power transfer while simultaneously maintaining Gbps data rate and nanosecond latency communication.

2022 30th European Signal Processing Conference (EUSIPCO), 2022

Simultaneous wireless information and power transfer (SWIPT) has the potential to realize the env... more Simultaneous wireless information and power transfer (SWIPT) has the potential to realize the envisioned ubiquity of the internet of things (IoT) by energizing them wirelessly whilst exchanging information. Recently, low-complexity receiver architectures for SWIPT are being considered for decoding information from amplitude modulated signals after rectification. However, less attention is paid towards improving the non-linear rectifier model prevalent in these architectures which is often truncated till fourth-order term in diode characteristic. In this paper, a novel, tractable analytical model for the rectenna non-linearity is presented which provides a theoretical upper bound to harvested DC power over the amplitude shift keying (ASK) constellation space corresponding to the entire diode non-linear region. Besides, the work also exposes the convexity of harvested DC power vis-à-vis incoming signal power thereby verifying the rate-energy (R-E) tradeoff in SWIPT for different choices of transmitted symbol amplitude distributions. Finally, the theoretical results presented using the adopted model are substantiated with the Monte Carlo circuit simulations allowing to conveniently evaluate and draw compromise in SWIPT performance against a choice of modulation scheme out of the ASK constellation space.

2021 55th Asilomar Conference on Signals, Systems, and Computers, 2021

2017 International Conference on Digital Image Computing: Techniques and Applications (DICTA), 2017

A multi-view multi-target correspondence framework employing deep learning on overlapping cameras... more A multi-view multi-target correspondence framework employing deep learning on overlapping cameras for identity-aware tracking in the presence of occlusion is proposed. Our complete pipeline of detection, multi-view correspondence, fusion and tracking, inspired by AI greatly improves person correspondence across multiple wide-angled views over traditionally used features set and handcrafted descriptors. We transfer the learning of a deep convolutional neural net (CNN) trained to jointly learn pedestrian features and similarity measures, to establish identity correspondence of non-occluding targets across multiple overlapping cameras with varying illumination and human pose. Subsequently, the identity-aware foreground principal axes of visible targets in each view are fused onto top view without requirement of camera calibration and precise principal axes length information. The problem of ground point localisation of targets on top view is then solved via linear programming for optimal projected axes intersection points to targets assignment using identity information from individual views. Finally, our proposed scheme is evaluated under tracking performance measures of MOTA and MOTP on benchmark video sequences which demonstrate high accuracy results when compared to other well-known approaches.

Advances in Intelligent Systems and Computing, 2018

Attention towards Intelligent Transportation System (ITS) has increased manifold especially due t... more Attention towards Intelligent Transportation System (ITS) has increased manifold especially due to prevailing security situation in the past decade. An integral part of ITS is video-based surveillance systems extracting real-time traffic parameters such as vehicle counting, vehicle classification, vehicle velocity etc. using stationary cameras installed on road sides. In all these systems, robust and reliable detection of vehicles is significantly a critical step. Since, several vehicle detection techniques exist, evaluating these techniques with respect to different environment conditions and application scenarios will give a better choice for actual deployment. The paper presents a concise survey of vehicle detection techniques used in diverse applications of video-based surveillance systems. Moreover, three main detection algorithms; Gaussian Mixture Model (GMM), Histogram of Gradients (HoG), and Adaptive motion Histograms based vehicle detection are implemented and evaluated for performance under varying illumination, traffic density and occlusion conditions. The survey provides a ready-reference for preferred vehicle detection technique under different applications.

EURASIP Journal on Advances in Signal Processing, 2016

Modern pulse compression radar involves digital signal processing of high bandwidth pulses modula... more Modern pulse compression radar involves digital signal processing of high bandwidth pulses modulated with different coding schemes. One of the limiting factors in the radar’s design to achieve desired target range and resolution is the need of high rate analog-to-digital (A/D) conversion fulfilling the Nyquist sampling criteria. The high sampling rates necessitate huge storage capacity, more power consumption, and extra processing requirement. We introduce a new approach to sample wideband radar waveform modulated with Costas sequence at a sub-Nyquist rate based upon the concept of compressive sensing (CS). Sub-Nyquist measurements of Costas sequence waveform are performed in an analog-to-information (A/I) converter based upon random demodulation replacing traditional A/D converter. The novel work presents an 8-order Costas coded waveform with sub-Nyquist sampling and its reconstruction. The reconstructed waveform is compared with the conventionally sampled signal and depicts high-quality signal recovery from sub-Nyquist sampled signal. Furthermore, performance of CS-based detections after reconstruction are evaluated in terms of receiver operating characteristic (ROC) curves and compared with conventional Nyquist-rate matched filtering scheme.

Brain tumor segmentation in Magnetic Resonance Imaging (MRI) scans provides vital information to ... more Brain tumor segmentation in Magnetic Resonance Imaging (MRI) scans provides vital information to radiologists in the diagnosis and staging of disease. However, these MRI scans are often corrupted with noise during its acquisition. Traditional approaches to this problem employ denoising which leads, in general, to edge smoothing and development of artifacts in MRI slices, thereby affecting tumor segmentation performance. In this paper, we employed graph signal processing (GSP) theory to first segment tumor core in each MRI slice using graph Laplacian followed by edge-aware denoising which is performed in synergy. The paper aims to present a novel technique to tackle the two problems of segmentation and denoising both under the GSP framework. The experimental results demonstrated on simulated and clinical brain MRI datasets, show highly competitive performance both in terms of tumor core segmentation under Dice and Sensitivity measures, and in terms of edge-aware denoising under PSNR ...

IEEE Access, 2022

Decoding communication signals in a non-cooperative environment has always been a challenging tas... more Decoding communication signals in a non-cooperative environment has always been a challenging task. Even after the estimation of various transmission-related parameters, the unknown received signal still cannot be decoded without the correct classification of the incorporated line coding scheme. In this paper, a robust short-sample feature-based approach is presented which recognizes line coding schemes in a sequential manner by an in-depth examination of linked characteristic features. The proposed approach provides an overall correct classification accuracy higher than 90 percent with an input of just 13 bit-waveforms whereas perfect classification accuracy (100 percent) is achieved with just 30 bit-waveforms of the unknown received signal. A detailed comparison considering noiseless as well as noisy channel environment is also carried out vis-à-vis existing approach based on extensive simulation results. Additionally, the paper bridges the gap between theory and simulations to justify the obtained accuracy results for conventional line codes under consideration. The substantial increase in classification accuracy for a smaller number of input bit-waveforms shall aid effective decoding of the unknown received signal even at the initial stages of reception. In general, it can benefit many practical spectrum surveillance applications, where proactiveness is paramount.

Springer, Cham - World Conference on Information Systems and Technologies, 2018

Attention towards Intelligent Transportation System (ITS) has increased manifold especially due t... more Attention towards Intelligent Transportation System (ITS) has increased manifold especially due to prevailing security situation in the past decade. An integral part of ITS is video-based surveillance systems extracting real-time traffic parameters such as vehicle counting, vehicle classification, vehicle velocity etc. using stationary cameras installed on road sides. In all these systems, robust and reliable detection of vehicles is significantly a critical step. Since, several vehicle detection techniques exist, evaluating these techniques with respect to different environment conditions and application scenarios will give a better choice for actual deployment. The paper presents a concise survey of vehicle detection techniques used in diverse applications of video-based surveillance systems. Moreover, three main detection algorithms; Gaussian Mixture Model (GMM), Histogram of Gradients (HoG), and Adaptive motion Histograms based vehicle detection are implemented and evaluated for...

2023 IEEE Pulsed Power Conference (PPC)

The Imaging Science Journal, Jul 1, 2013

Single-photon emission computerised tomography (SPECT) and positron emission tomography (PET) are... more Single-photon emission computerised tomography (SPECT) and positron emission tomography (PET) are essential medical imaging tools, with inherent drawback of slow data acquisition process. We present a novel compressed sensing-based reconstruction of these images from significantly fewer measurements than traditionally required, thus demonstrating potential of reduction in scan time and radiopharmaceutical doze with benefits for patients and health care economics. Our work effectively shows that high fidelity two-dimensional (2D) SPECT/PET image is reconstructed using compressive sensing with considerably reduced numbers of samples in acquisition stage. The reconstruction of tomographic images is realised by compressed sensing the 2D Fourier projections of k-space data. These 2D projections being sparse in transform domain need fewer samples in k-space and are reconstructed without loss of fidelity. These undersampled Fourier projections can then be backprojected by employing the iterative reconstruction approach for a complete three-dimensional (3D) volume. Compressed sensing of a phantom image and PET bone scintigraphy with radial Fourier samples are performed. The reconstructions of these images are compared to conventionally sampled images using image quality measures like mean square error, peak signal-to-noise ratio and structure similarity (SSIM) index, showing high-quality image reconstruction.

The broad spectrum available in Terahertz (THz) band is envisaged to simultaneously meet both dat... more The broad spectrum available in Terahertz (THz) band is envisaged to simultaneously meet both data and energy demands of the next-generation battery-limited wireless devices. Recent advances in THz semiconductor technologies and antenna design are closing the gap in low-powered millimeter-scale receiver architectures. Consequently, prospective signal processing and modulation schemes are emerging for base-station transmission to achieve efficient power and high-rate information transfer to an integrated receiver (IntRx). In this paper, we present for the first time an on-off keying (OOK) power modulation scheme for simultaneous THz information and power transfer (STIPT) to an IntRx involving a THz diode-based rectenna demodulator. A novel non-linear rectenna model is first proposed which provides a theoretical upper bound to harvested DC power. By leveraging the convexity of harvested DC power to incoming single-carrier signal power, an OOK power modulation scheme is then designed to maximize power transfer under available input power constraints. Lastly, both theoretical and simulation results involving a THz band GaAs Schottky diode demonstrate that the proposed scheme maximizes power transfer while simultaneously maintaining Gbps data rate and nanosecond latency communication.

IEEE Journal of Selected Topics in Signal Processing, 2023

Terahertz (THz) band transmission has the potential to revolutionize future-generation wireless n... more Terahertz (THz) band transmission has the potential to revolutionize future-generation wireless networks by jointly meeting communication and non-communication demands of their connected devices. Recent advances in THz semiconductor technologies and antenna design are closing the THz band gap in millimeter-scale devices which are often battery-limited. The localization of these mobile devices in future wireless networks is of paramount significance for beamforming to overcome THz propagation loss. Consequently, prospective signal processing techniques with co-design architectures are emerging either for joint communication and sensing or for simultaneous information and power transfer. In this paper, we present a novel approach toward Simultaneous Terahertz Imaging with Information and Power Transfer (STIIPT) from a base station transceiver to an Integrated Receiver (IntRx). Leveraging the proposed non-linear rectenna model for energy harvesting, a customized On-Off Keying (cOOK) modulation scheme is proposed for simultaneous communication through a non-linear THz channel while generating a radar-like image to localize the IntRx acting as a target. The proposed theoretical models are corroborated with simulations using a THz band GaAs Schottky diode to demonstrate STIIPT performances which also emphasize the significance of ranging information to optimize rate–energy transfer tradeoff under the cOOK modulation scheme. THz band, 6G, non-linear model, rectenna, IntRx, customized OOK modulation, 2D radar imaging, STIIPT

2022 30th European Signal Processing Conference (EUSIPCO), Aug 29, 2022

Simultaneous wireless information and power transfer (SWIPT) has the potential to realize the env... more Simultaneous wireless information and power transfer (SWIPT) has the potential to realize the envisioned ubiquity of the internet of things (IoT) by energizing them wirelessly whilst exchanging information. Recently, low-complexity receiver architectures for SWIPT are being considered for decoding information from amplitude modulated signals after rectification. However, less attention is paid towards improving the non-linear rectifier model prevalent in these architectures which is often truncated till fourth-order term in diode characteristic. In this paper, a novel, tractable analytical model for the rectenna non-linearity is presented which provides a theoretical upper bound to harvested DC power over the amplitude shift keying (ASK) constellation space corresponding to the entire diode non-linear region. Besides, the work also exposes the convexity of harvested DC power vis-à-vis incoming signal power thereby verifying the rate-energy (R-E) tradeoff in SWIPT for different choices of transmitted symbol amplitude distributions. Finally, the theoretical results presented using the adopted model are substantiated with the Monte Carlo circuit simulations allowing to conveniently evaluate and draw compromise in SWIPT performance against a choice of modulation scheme out of the ASK constellation space.

Brain tumor segmentation in Magnetic Resonance Imaging (MRI) scans provides vital information to ... more Brain tumor segmentation in Magnetic Resonance Imaging (MRI) scans provides vital information to radiologists in the diagnosis and staging of disease. However, these MRI scans are often corrupted with noise during its acquisition. Traditional approaches to this problem employ denoising which leads, in general, to edge smoothing and development of artifacts in MRI slices, thereby affecting tumor segmentation performance. In this paper, we employed graph signal processing (GSP) theory to first segment tumor core in each MRI slice using graph Laplacian followed by edge-aware denoising which is performed in synergy. The paper aims to present a novel technique to tackle the two problems of segmentation and denoising both under the GSP framework. The experimental results demonstrated on simulated and clinical brain MRI datasets, show highly competitive performance both in terms of tumor core segmentation under Dice and Sensitivity measures, and in terms of edge-aware denoising under PSNR and SSIM measures.

2023 IEEE Wireless Power Technology Conference and Expo (WPTCE)

A breakthrough in the 6G wireless network is imminent with the employment of Terahertz (THz) band... more A breakthrough in the 6G wireless network is imminent with the employment of Terahertz (THz) band transmission to meet both the information and energy demands of their connected devices simultaneously. Inspired by the advances in the THz neighboring bands, a novel non-linear model of an intensity-modulation and direct-detection (IM/DD) is proposed to perform simultaneous THz information and power transfer (STIPT) over a 6G point-to-point link. We present a non-truncated yet tractable analytical diode model of a rectenna-based DD receiver and find an upper bound for the harvested DC power over an IM transmission. Besides, the simultaneous achievable information rate is evaluated for a power-maximizing input traveling through a distance-dependent THz channel. The theoretical model is supported with simulations involving both ideal and real THz GaAs Schottky diode parameters to assess STIPT performance. The results demonstrate that by employing an on-off keying (OOK) scheme in the IM/DD model, a 6G network of battery-less devices can be extended up to several meters while communicating at a Gbps data rate.

... Adnan Hanif a, Atif Bin Mansoor a, Tahira Ejaz b ... 23, April 2004. [11] Zhou Wang, Alan C. ... more ... Adnan Hanif a, Atif Bin Mansoor a, Tahira Ejaz b ... 23, April 2004. [11] Zhou Wang, Alan C. Bovik,Hamid R. Sheikh, and Eero P. Simoncelli, “Image quality assessment: From error measurement to structural similarity,” IEEE Trans-actions on Image Processing, vol. ...

IEEE Wireless Power Technology Conference and Expo (WPTCE), 2023

A breakthrough in the 6G wireless network is imminent with the employment of Terahertz (THz) band... more A breakthrough in the 6G wireless network is imminent with the employment of Terahertz (THz) band transmission to meet both the information and energy demands of their connected devices simultaneously. Inspired by the advances in the THz neighboring bands, a novel non-linear model of an intensity-modulation and direct-detection (IM/DD) is proposed to perform simultaneous THz information and power transfer (STIPT) over a 6G point-to-point link. We present a non-truncated yet tractable analytical diode model of a rectenna-based DD receiver and find an upper bound for the harvested DC power over an IM transmission. Besides, the simultaneous achievable information rate is evaluated for a power-maximizing input traveling through a distance-dependent THz channel. The theoretical model is supported with simulations involving both ideal and real THz GaAs Schottky diode parameters to assess STIPT performance. The results demonstrate that by employing an on-off keying (OOK) scheme in the IM/DD model, a 6G network of battery-less devices can be extended up to several meters while communicating at a Gbps data rate.

IEEE Journal of Selected Topics in Signal Processing

Terahertz (THz) band transmission has the potential to revolutionize future-generation wireless n... more Terahertz (THz) band transmission has the potential to revolutionize future-generation wireless networks by jointly meeting communication and non-communication demands of their connected devices. Recent advances in THz semiconductor technologies and antenna design are closing the THz band gap in millimeter-scale devices which are often battery-limited. The localization of these mobile devices in future wireless networks is of paramount significance for beamforming to overcome THz propagation loss. Consequently, prospective signal processing techniques with co-design architectures are emerging either for joint communication and sensing or for simultaneous information and power transfer. In this paper, we present a novel approach toward Simultaneous Terahertz Imaging with Information and Power Transfer (STIIPT) from a base station transceiver to an Integrated Receiver (IntRx). Leveraging the proposed non-linear rectenna model for energy harvesting, a customized On-Off Keying (cOOK) modulation scheme is proposed for simultaneous communication through a non-linear THz channel while generating a radar-like image to localize the IntRx acting as a target. The proposed theoretical models are corroborated with simulations using a THz band GaAs Schottky diode to demonstrate STIIPT performances which also emphasize the significance of ranging information to optimize rate–energy transfer tradeoff under the cOOK modulation scheme. THz band, 6G, non-linear model, rectenna, IntRx, customized OOK modulation, 2D radar imaging, STIIPT

IEEE Journal of Selected Topics in Signal Processing, 2023

Terahertz (THz) band transmission has the potential to revolutionize future-generation wireless n... more Terahertz (THz) band transmission has the potential to revolutionize future-generation wireless networks by jointly meeting communication and non-communication demands of their connected devices. Recent advances in THz semiconductor technologies and antenna design are closing the THz band gap in millimeter-scale devices which are often battery-limited. The localization of these mobile devices in future wireless networks is of paramount significance for beamforming to overcome THz propagation loss. Consequently, prospective signal processing techniques with co-design architectures are emerging either for joint communication and sensing or for simultaneous information and power transfer. In this paper, we present a novel approach toward Simultaneous Terahertz Imaging with Information and Power Transfer (STIIPT) from a base station transceiver to an Integrated Receiver (IntRx). Leveraging the proposed non-linear rectenna model for energy harvesting, a customized On-Off Keying (cOOK) modulation scheme is proposed for simultaneous communication through a non-linear THz channel while generating a radar-like image to localize the IntRx acting as a target. The proposed theoretical models are corroborated with simulations using a THz band GaAs Schottky diode to demonstrate STIIPT performances which also emphasize the significance of ranging information to optimize rate–energy transfer tradeoff under the cOOK modulation scheme.
THz band, 6G, non-linear model, rectenna, IntRx, customized OOK modulation, 2D radar imaging, STIIPT

2022 56th Asilomar Conference on Signals, Systems, and Computers, 2022

The broad spectrum available in Terahertz (THz) band is envisaged to simultaneously meet both dat... more The broad spectrum available in Terahertz (THz) band is envisaged to simultaneously meet both data and energy demands of the next-generation battery-limited wireless devices. Recent advances in THz semiconductor technologies and antenna design are closing the gap in low-powered millimeter-scale receiver architectures. Consequently, prospective signal processing and modulation schemes are emerging for base-station transmission to achieve efficient power and high-rate information transfer to an integrated receiver (IntRx). In this paper, we present for the first time an on-off keying (OOK) power modulation scheme for simultaneous THz information and power transfer (STIPT) to an IntRx involving a THz diode-based rectenna demodulator. A novel non-linear rectenna model is first proposed which provides a theoretical upper bound to harvested DC power. By leveraging the convexity of harvested DC power to incoming single-carrier signal power, an OOK power modulation scheme is then designed to maximize power transfer under available input power constraints. Lastly, both theoretical and simulation results involving a THz band GaAs Schottky diode demonstrate that the proposed scheme maximizes power transfer while simultaneously maintaining Gbps data rate and nanosecond latency communication.

2022 30th European Signal Processing Conference (EUSIPCO), 2022

Simultaneous wireless information and power transfer (SWIPT) has the potential to realize the env... more Simultaneous wireless information and power transfer (SWIPT) has the potential to realize the envisioned ubiquity of the internet of things (IoT) by energizing them wirelessly whilst exchanging information. Recently, low-complexity receiver architectures for SWIPT are being considered for decoding information from amplitude modulated signals after rectification. However, less attention is paid towards improving the non-linear rectifier model prevalent in these architectures which is often truncated till fourth-order term in diode characteristic. In this paper, a novel, tractable analytical model for the rectenna non-linearity is presented which provides a theoretical upper bound to harvested DC power over the amplitude shift keying (ASK) constellation space corresponding to the entire diode non-linear region. Besides, the work also exposes the convexity of harvested DC power vis-à-vis incoming signal power thereby verifying the rate-energy (R-E) tradeoff in SWIPT for different choices of transmitted symbol amplitude distributions. Finally, the theoretical results presented using the adopted model are substantiated with the Monte Carlo circuit simulations allowing to conveniently evaluate and draw compromise in SWIPT performance against a choice of modulation scheme out of the ASK constellation space.

2021 55th Asilomar Conference on Signals, Systems, and Computers, 2021

2017 International Conference on Digital Image Computing: Techniques and Applications (DICTA), 2017

A multi-view multi-target correspondence framework employing deep learning on overlapping cameras... more A multi-view multi-target correspondence framework employing deep learning on overlapping cameras for identity-aware tracking in the presence of occlusion is proposed. Our complete pipeline of detection, multi-view correspondence, fusion and tracking, inspired by AI greatly improves person correspondence across multiple wide-angled views over traditionally used features set and handcrafted descriptors. We transfer the learning of a deep convolutional neural net (CNN) trained to jointly learn pedestrian features and similarity measures, to establish identity correspondence of non-occluding targets across multiple overlapping cameras with varying illumination and human pose. Subsequently, the identity-aware foreground principal axes of visible targets in each view are fused onto top view without requirement of camera calibration and precise principal axes length information. The problem of ground point localisation of targets on top view is then solved via linear programming for optimal projected axes intersection points to targets assignment using identity information from individual views. Finally, our proposed scheme is evaluated under tracking performance measures of MOTA and MOTP on benchmark video sequences which demonstrate high accuracy results when compared to other well-known approaches.

Advances in Intelligent Systems and Computing, 2018

Attention towards Intelligent Transportation System (ITS) has increased manifold especially due t... more Attention towards Intelligent Transportation System (ITS) has increased manifold especially due to prevailing security situation in the past decade. An integral part of ITS is video-based surveillance systems extracting real-time traffic parameters such as vehicle counting, vehicle classification, vehicle velocity etc. using stationary cameras installed on road sides. In all these systems, robust and reliable detection of vehicles is significantly a critical step. Since, several vehicle detection techniques exist, evaluating these techniques with respect to different environment conditions and application scenarios will give a better choice for actual deployment. The paper presents a concise survey of vehicle detection techniques used in diverse applications of video-based surveillance systems. Moreover, three main detection algorithms; Gaussian Mixture Model (GMM), Histogram of Gradients (HoG), and Adaptive motion Histograms based vehicle detection are implemented and evaluated for performance under varying illumination, traffic density and occlusion conditions. The survey provides a ready-reference for preferred vehicle detection technique under different applications.

EURASIP Journal on Advances in Signal Processing, 2016

Modern pulse compression radar involves digital signal processing of high bandwidth pulses modula... more Modern pulse compression radar involves digital signal processing of high bandwidth pulses modulated with different coding schemes. One of the limiting factors in the radar’s design to achieve desired target range and resolution is the need of high rate analog-to-digital (A/D) conversion fulfilling the Nyquist sampling criteria. The high sampling rates necessitate huge storage capacity, more power consumption, and extra processing requirement. We introduce a new approach to sample wideband radar waveform modulated with Costas sequence at a sub-Nyquist rate based upon the concept of compressive sensing (CS). Sub-Nyquist measurements of Costas sequence waveform are performed in an analog-to-information (A/I) converter based upon random demodulation replacing traditional A/D converter. The novel work presents an 8-order Costas coded waveform with sub-Nyquist sampling and its reconstruction. The reconstructed waveform is compared with the conventionally sampled signal and depicts high-quality signal recovery from sub-Nyquist sampled signal. Furthermore, performance of CS-based detections after reconstruction are evaluated in terms of receiver operating characteristic (ROC) curves and compared with conventional Nyquist-rate matched filtering scheme.

Brain tumor segmentation in Magnetic Resonance Imaging (MRI) scans provides vital information to ... more Brain tumor segmentation in Magnetic Resonance Imaging (MRI) scans provides vital information to radiologists in the diagnosis and staging of disease. However, these MRI scans are often corrupted with noise during its acquisition. Traditional approaches to this problem employ denoising which leads, in general, to edge smoothing and development of artifacts in MRI slices, thereby affecting tumor segmentation performance. In this paper, we employed graph signal processing (GSP) theory to first segment tumor core in each MRI slice using graph Laplacian followed by edge-aware denoising which is performed in synergy. The paper aims to present a novel technique to tackle the two problems of segmentation and denoising both under the GSP framework. The experimental results demonstrated on simulated and clinical brain MRI datasets, show highly competitive performance both in terms of tumor core segmentation under Dice and Sensitivity measures, and in terms of edge-aware denoising under PSNR ...

IEEE Access, 2022

Decoding communication signals in a non-cooperative environment has always been a challenging tas... more Decoding communication signals in a non-cooperative environment has always been a challenging task. Even after the estimation of various transmission-related parameters, the unknown received signal still cannot be decoded without the correct classification of the incorporated line coding scheme. In this paper, a robust short-sample feature-based approach is presented which recognizes line coding schemes in a sequential manner by an in-depth examination of linked characteristic features. The proposed approach provides an overall correct classification accuracy higher than 90 percent with an input of just 13 bit-waveforms whereas perfect classification accuracy (100 percent) is achieved with just 30 bit-waveforms of the unknown received signal. A detailed comparison considering noiseless as well as noisy channel environment is also carried out vis-à-vis existing approach based on extensive simulation results. Additionally, the paper bridges the gap between theory and simulations to justify the obtained accuracy results for conventional line codes under consideration. The substantial increase in classification accuracy for a smaller number of input bit-waveforms shall aid effective decoding of the unknown received signal even at the initial stages of reception. In general, it can benefit many practical spectrum surveillance applications, where proactiveness is paramount.

Springer, Cham - World Conference on Information Systems and Technologies, 2018

Attention towards Intelligent Transportation System (ITS) has increased manifold especially due t... more Attention towards Intelligent Transportation System (ITS) has increased manifold especially due to prevailing security situation in the past decade. An integral part of ITS is video-based surveillance systems extracting real-time traffic parameters such as vehicle counting, vehicle classification, vehicle velocity etc. using stationary cameras installed on road sides. In all these systems, robust and reliable detection of vehicles is significantly a critical step. Since, several vehicle detection techniques exist, evaluating these techniques with respect to different environment conditions and application scenarios will give a better choice for actual deployment. The paper presents a concise survey of vehicle detection techniques used in diverse applications of video-based surveillance systems. Moreover, three main detection algorithms; Gaussian Mixture Model (GMM), Histogram of Gradients (HoG), and Adaptive motion Histograms based vehicle detection are implemented and evaluated for...