In order to test the validity of signal phase matching principle （SPMP） applied to direction of arrival （DOA） estimation, experiments are carried out at a reservoir using 16 sensors array. Two kinds of method, Least Square Method for Signal Matching principle （LSMSPM） and singular value decomposition method for signal matching principle （SVDSPM）, are used for DOA estimation. Their performances were analyzed and compared with MUSIC and conventional beam-forming （CBF） method. The results show that the 3 dB beam width obtained by SPMP is 1/4 to 1/7 as much as that obtained by CBF and 1/2 to 1/3 by MUSIC method. In addition, LSMSPM and SVDSPM are available for multi-sources DOA estimation and high resolution DOA estimation, which demonstrates that DOA estimation by SPMP method is better than that by MUSIC and CBF method.
Based on adaptive technique, a design method for broadband array with frequency invariant beam pattern is presented. For a given beam pattern, the all design process can be completed automatically by computer without deriving expression of weight vector. The design process is divided into three steps: (1) Evaluate the weight vector in reference frequency by numerical method. (2) Obtain the weight vectors in other frequency by adaptive technique. (3) For the design target of frequency response given by weight vector at different frequency point, design FIR filter. The proposed method can be applied to arbitrary array and have no restriction on element patterns.
A new method of estimating the frequency-known signals from the strong background noise was presented first. Then the new method was used in the demodulation of the digital frequency modulation (FSK) signals. The new demodulation method can complete the demodulation of the FSK signals only with the carrier frequency and without any carrier phase information. The simulation results show that the performance of anti-noise of the new method is better than that of the incoherent demodulation method and the fluctuation of the carrier phase has little effect on the new method. So the new demodulation method has a fine prospect in the practical applications.
