Software defined radar system
Authors: Hui Zhang
Venue:  (2008)

In this thesis, a novel type of radar system in the form of a software defined radar is proposed. By means of an entirely software defined reconfigurability, a number of different functionalities of conventional radar systems can be realized and integrated within a single device in order to satisfy demands and performance requirements for multiple application scenarios. The presented radar system can be used in a large variety of fields. One of its most important applications is related to the automotive industry for an accurate range and speed measurement in combination with a high-performance inter-vehicle communication capability. Other fields for the use of a software defined radar as presented in this work include safety applications, such as security screening at airports and surveillance tasks, but also airborne or military applications. The radar system presented in this work provides three different modulation schemes: frequency modulated continuous wave (FMCW), continuous wave (CW), and spread spectrum (SS) operation. Moreover, different signal processing algorithms for each operation are implemented and tested, such as the superresolution PN correlation method (SPM), the Teager Kaiser (TK) method, and the wavelet method. The conventional FMCW radar technique is used to find the approximate range of the target. Then, an ambiguous but very accurate set of range solutions is determined by a CW measurement. The correct precision CW distance measurement is resolved on the basis of the approximate FMCW solution. In addition, SS radar is included in the system to measure distance in high interference environments. The entire system concept is modeled in a high-level MATLAB/Simulink environment in order to provide a good performance and functionality prediction for the proposed radar system. In addition, this model allows for a detailed assessment of performance and working principle of each single design block and each of the signal processing algorithms. An extensive performance study of the proposed system is presented in order to provide a good theoretical insight into the radar functionality and different achievable performance aims such as resolution, accuracy, and range ambiguity. On the basis of these simulations and theoretical considerations, two software defined radar prototypes at frequencies of 4 GHz and 24 GHz, respectively, are designed, fabricated, and measured. These prototypes include a microwave front end with two different architectures. One is a heterodyne transceiver based on a conventional mixer, whereas the second proposed structure is based on a six-port detector as the demodulating element. Moreover, the project introduces a novel two-stage six-port calibration approach that extends the six-port conventional operation range to higher power levels. The performance of both architectures is compared and analyzed both in simulation and measurement and the results agree very well both in simulation, measurement, and theoretical analysis. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player