| In many communication environments, it is of interest to find the Direction of Arrival (DOA) of a detected signal and its characteristics. In estimating the DOA of a signal impinging on a linear array, the signal is often assumed to be both sinusoidal and stationary. In this dissertation, we are instead interested in estimating the DOA and the Frequency Sweeping Rate (FSR) of a chirp signal which can be considered as a non-stationary signal. Many radar signals take on the form of a chirp signal. Furthermore, in mobile communication, a chirp signal is created due to a Doppler shift in the frequency of the received signal when the target is moving. The DOA of the received signal shows the direction of the source, while the FSR indicates additional characteristics of the target. Hence, both the DOA and the FSR of the chirp signal must be estimated.; In this dissertation, a fast estimation procedure for both the DOA and FSR of a linear chirp signal is proposed based on the maximum likelihood method. Furthermore, a novel estimation technique associated with the Discretized version of the Continuous Wavelet Transform (DCWT) is also proposed. The DCWT is used because of its ability to handle non-stationary signals and to present the information in a manner analogous to the time-frequency plots. |
