Ranging Accuracy and Doppler Tolerance of CW Signal Based on Pseudo-Random Code Bi-Phase Modulation
Ambiguity function method is used to study the ranging and Doppler tolerance performance of CW signal based on pseudo-random code bi-phase modulation (PRCBPM). Its ranging resolution and Doppler tolerance confine are calculated, the ranging performance and Doppler tolerance capability are simulated by using the software of Matlab and the influence factors are analyzed. The simulation results are consistent with the calculation values. The results show that the ranging precision of PRCBPM signal depends on the code width and is more improved with the narrower code width, and that the Doppler tolerance performance lies on and is inverse proportion to the product of code width and code length.
AbstractAn exact solution is established pertaining to the problem of undamped free vibration of a thin circular plate resting on a Winkler foundation with variable subgrade modulus. The solution is performed by applying the infinite power series method. Moreover, the solution procedure is demonstrated through an illustrative example, wherein the general frequency equation is derived for two different boundary conditions. The correctness of the solution is also verified using results available in the literature. Finally, it is shown that the proposed method of solution is directly applicable to the more-general problem of circular plates on a variable-modulus Pasternak-type foundation.