الفهرس 
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Abstract
Nearly all modern commercial and military radios are Digital Signal Processor based (DSP-based) radios. Modern wireless communication systems have always combined digital signal processing and analog radio frequency. Signal processing has advanced to the point where most baseband functionality is performed in software. At the same time, modern Radio Frequency (RF) hardware can be reconfigured, enabling a single radio front end to handle many RF systems. This innovative combination resulted in Software-Defined Radio (SDR) development. Modern SDR-based systems allow communication between various communication systems. Additionally, new waveforms can be produced and deployed with standards to add new capabilities. SDR enables increased utilization, cost savings, and postpone obsolescence by enabling current software and hardware to adopt new capabilities and features through software updates.
Radar systems are an interesting application of SDR due to SDR’s low cost and high configurability compared to traditional radar systems. A survey on the latest implemented radar systems using SDR is reviewed, and the platforms used to implement these solutions are studied and compared to the proposed designed and implemented SDR platform.
During this research, a complete SDR system is designed and implemented. The proposed SDR contains four different boards; digital signal processor, a high-speed data acquisition board, an RF front-end, and a local oscillator board. The components used in this design were chosen carefully to afford a wide operating range, high speed, low power dissipation, small size, low cost, configurability, low noise, and good performance. Many considerations are taken into account to get a good performance; digital traces length-tuning, differential pairs length-matching, power delivery networks optimization, transmission lines impedance matching, board isolation, and thermal optimization. The implemented SDR can transmit and receive signals up to
6.8 GHz with 100 MHz instantaneous bandwidth. The system’s small size and good performance suit portable UAVs, SAR, and imaging radars. Several laboratory and field tests were performed to evaluate the proposed design performance.
A basic and straightforward technique is used to build and develop a radar waveform generator on the developed SDR platform. This radar waveform generator can generate different waveforms by defining the values of a number of online-configurable variables. Compared to the current state of the art, the resources have been lowered by more than fifty percent. The produced waveform can be changed inside the processing unit in real-time.
Through-wall imaging radar has recently attracted significant attention because of its many applications. These radars are vital in disaster assistance, firefighting, counterterrorism, and civilian law enforcement.
The present thesis used the implemented SDR as a Frequency Modulated Continuous Wave (FMCW) radar system capable of detecting motion behind numerous barriers by employing a Field Programmable Gate Array (FPGA) as a real-time signal processor. Digital raw data is processed in real-time through several signal processing stages to suppress noise, jamming, antenna leakage, ground, and wall reflection and to achieve high performance. These processing stages includes windowing, filtering, Fast Fourier transformation (FFT), Moving Target Indication (MTI), and a Constant False Alarm Rate stage (CFAR)
The proposed UWB FMCW radar can penetrate walls and provide exact range resolution to overcome any masking concerns that may develop during detection. Rather than transmitting high power to provide adequate signal detection performance, the minimum detectable signal is enhanced to permit long-term indoor usage. A narrow instantaneous bandwidth is also employed to improve receiver sensitivity and noise suppression. With a range of 25 m, a resolution of 20 cm, and a transmitter power of 16 mW, the proposed radar could effectively give the range profile of a moving person around a room and behind one or two brick walls.
The thesis consists of five chapters, including a table of contents, a list of figures, abbreviations, symbols, and tables, as well as a list of references.
Chapter 1: Contains a thesis introduction, motivations, and objective.
Chapter 2: This chapter outlines the evolution of software-defined radio technology and discusses the fundamental design and implementation of SDR subsystems. Following that, an overview of generic radar system is provided. The primary radar subsystems are studied, deduced the general radar equation and the radar frequency bands and their influence on the radar design and system requirements.
Chapter 3: This chapter discusses the design and implementation of different boards combining a modern SDR platform.
Chapter 4: This chapter represents two applications for the implemented SDR to evaluate its performance and capabilities. The first application is
a waveform generator based on the SDR platform to generate various waveforms with low resources. The second application is a radar system to detect motion in free space and behind multiple walls.
Chapter 5: This chapter concludes the thesis’s work and discusses future research endeavors.