Anowar Hossain

Adaptive UWB-OFDM Synthetic Aperture Radar

This paper presents an empirical study of high resolution potentially jamming-resistant Synthetic Aperture Radar (SAR) system based on UWB-OFDM architecture. The Range-Doppler Algorithm (RDA) was used to construct a high resolution SAR image for simulation purpose. Suitable waveforms to achieve high resolution SAR imaging are proposed for both friendly and hostile environments. The proposed waveforms were tested for a point scatterer and for full 2-D SAR image construction. Simulation results demonstrate the benefits of using UWB-OFDM waveforms for SAR system, such as dynamic spectrum allocation, antijamming potential through pulse diversity-while having a potential to produce high resolution target images. The use of UWB-OFDM waveform for SAR system proves useful for high resolution image data collection for civilian purposes and provides significant anti-jamming capabilities for military purposes.

High-resolution and jamming-resistant UWB-OFDM SAR imaging

High resolution and potentially jamming-resistant Synthetic Aperture Radar (SAR) system is presented based on UWB-OFDM architecture. The Omega-K Algorithm (ωKA) is used to construct high resolution SAR image. Suitable waveforms to achieve high resolution SAR image are proposed for both friendly and hostile environments. The proposed waveforms were tested for a point scatterer and for full 2-D SAR image construction.

High-resolution and Wide-swath UWB OFDM MIMO Synthetic Aperture Radar System Using Image Fusion

MIMO radar has received significant attention to radar communities recently. This paper presents a novel scheme for wide-swath and high-resolution synthetic aperture radar based on a MIMO UWB-OFDM system. The swath is increased based on a new approach for orthogonal pulse-shaping and MIMO wide-swath SAR topology. The resolution is improved using UWB-OFDM waveforms. Performance is further enhanced using image fusion techniques to benefit from the potentials of multi-sensor imagery such as noise level reduction.

Waveform diversity for mutual interference mitigation in automotive radars under realistic traffic environments

This paper presents a novel approach for mutual interference mitigation in automotive radars based on advanced waveform design by imposing time and frequency diversity to frequency modulated continuous wave (FMCW) chirp signal. Performance of the proposed waveform has been investigated using software-defined radio transceiver, and measurement results are provided. The system concept is validated by developed automotive radar channel model considering realistic 3D road traffic scenario using a ray-tracing tool. Theoretical analysis and simulation examples of mutual interference scenarios in automotive environment are provided to evaluate the effectiveness of the proposed method. Performance of both conventional FMCW waveform and proposed waveform under mutual interference environments has been provided for fair comparison. Results show that the proposed system is able to detect the targets of interest successfully while mitigates the false targets in mutual interference environments.

Mutual interference mitigation in automotive radars under realistic road environments

With the increasing rate of modern vehicles equipped with automotive radars, mutual interference among multiple radars is becoming a critical issue. This paper presents a new approach for mutual interference mitigation based on frequency modulated continuous wave (FMCW) chirp diversity considering long-range automotive radar. The system concept is evaluated considering realistic road traffic scenario using a ray-tracing tool. Theoretical analysis and simulation of various mutual interference scenarios in automotive environment are provided to demonstrate the effectiveness of the proposed waveform. Results show that the proposed waveform exhibits successful target detection and mitigation of false targets in mutual interference environments.

Nearfield Imaging for Noninvasive Monitoring of Hyperthermia Treatment

Monitoring of thermal distribution in hyperthermia treatment depends on invasive intraluminal or interstitial probes. This research aims at developing a proficient platform that addresses some challenges of hyperthermia therapy. A model of forward problem is developed, incorporating dispersive wideband models of tissue properties. A tool is also developed to generate a dictionary that relates scattered signals to material features. Solution of the inverse problem is conducted based on compressed sensing techniques. With the dependence of tissue electrical properties on temperature, thermal maps are generated. Practical aspects of the nonlinearity associated with wideband power amplifiers are incorporated in the model. Analysis of the reconstructed images reveals the validity of the proposed techniques. In particular, encouraging results are obtained of thermal mapping, denoting the potential of using nearfield imaging as a noninvasive thermometry tool, in monitoring hyperthermia treatment.

Cooperative vehicular positioning with VANET in urban environments

Accurate vehicle-positioning is an important part of intelligent transportation system (ITS). Existing positioning techniques based on Global Positioning System (GPS) are not suitable for vehicular positioning because of higher positioning errors. Recently, positioning based on vehicle-to-vehicle (V2V) and vehicle-to-roadside unit (V2R) communication has emerged as an alternative more accurate solution. In this paper, we present cooperative vehicular positioning technique that provides higher accuracy than GPS-based positioning by fusion of V2V and V2R communication information, using time-or-arrival (TOA) data. Vehicular channel model is developed considering realistic urban road scenario, using ray-tracing simulation. Path-loss and received power levels are investigated for dedicated short-range communication (DSRC) at 5.9 GHz band. Results show considerable improvements in performance and consistent error reduction of the proposed technique compared to GPS-based positioning. In addition, enhancement is achieved considering V2V along with communication with three roadside units (RSUs), compared to conventional techniques that use V2R communication with four RSUs.