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nonlinear-frequency-modulation
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Automatic Intra Pulse Modulation Recognition of RF Signal with FPGA Implementation
, M.Sc. Thesis Sharif University of Technology ; Pezeshk, Amir Mansour (Supervisor)
Abstract
Automatic modulation recognition is an improving area in signal processing that has been interest of research institutes in recent years. Every signal intelligence system consists of three parts: Front, middle prcessing, Output. which Automatic recognition system is in the middle processing. Vast researches has been done on front and output section. By the way output section demands proper work by modulation recognition section in order to work appropriately. With the right knowledge of the receiving modulation, output section can jam or demodulate the receiving signal by demand. Intrapulse modulation in this research is the meaningful variation of frequency, amplitude or phase of a signal....
Optimal Waveform Design for MIMO-SAR Applications
, M.Sc. Thesis Sharif University of Technology ; Bastani, Mohammad Hassan (Supervisor)
Abstract
Studies regarding Multiple Input - Multiple Output synthetic aperture radars, shows promising advances in synthetic aperture imaging. Compared to conventional SAR, MIMO-SAR encompasses desirable features, namely: lower background noise, better detection rate, easier implementation of imaging modes etc. Signals used in these radars, are required to have specific properties such as orthogonality, large time-bandwidth product, high Doppler tolerance and qualified ambiguity function. Also because of the specific geometry of SAR imaging, these signals should remain orthogonal in respectively large Doppler shifts and time offsets. Through the past years, many signals are suggested in the...
Nonlinear FM waveform design to reduction of sidelobe level in autocorrelation function
, Article 2017 25th Iranian Conference on Electrical Engineering, ICEE 2017, 2 May 2017 through 4 May 2017 ; 2017 , Pages 1973-1977 ; 9781509059638 (ISBN) ; Babashah, H ; Sebt, M. A ; Sharif University of Technology
Abstract
This paper will design non-linear frequency modulation (NLFM) signal for Chebyshev, Kaiser, Taylor, and raised-cosine power spectral densities (PSDs). Then, the variation of peak sidelobe level with regard to mainlobe width for these four different window functions are analyzed. It has been demonstrated that reduction of sidelobe level in NLFM signal can lead to increase in mainlobe width of autocorrelation function. Furthermore, the results of power spectral density obtained from the simulation and the desired PSD are compared. Finally, error percentage between simulated PSD and desired PSD for different peak sidelobe level are illustrated. The stationary phase concept is the possible...