Research On Software PLL Technic And Design Of Receiver

In the underwater acoustic signal processing field, for the purpose of increasing SNR and obtaining the aiming signals with multi-frequency in time sharing, narrowband filters are desirable because of the frequency offsets of signals due to correspondingly moving among the target and sonar system. But for the CW signals with mutative central frequency, it is not practical to track and filter it with narrowband filters in ordinary hardware system.The PLL has been the most fundamental parts in electro-equipments and been used in communication, space flight, measurement, TV tech, nuclear power, electromotor controlling and so on. The tracking and filtering tech of signals have been recognized in academe and a world number of researching results have been worked out. However, most researching works of both domestic and overseas are focused on continuous signals and continue waves signal with wide frequency band takes less attention across the world which is seldom found among literatures.Based on basic principles of PLL, the influence to performance of capturing and tracking of PLL from system parameters is analyzed with the help of Matlab in this work. Software PLL system is designed to realize the phase track and lock for CW signals with the DSP5509A as the system CBD. The designing of hardware system of receiver is also included in this work. To obtain the phase coherence of multi-channels, those issues such as the types of filter, the PCB layout, the errors of the components value are concerned deeply in designing work of analog system and the parameters of components are discussed and given wisely.The experimentation indicates: the good performances and harmonious cooperation of analog system circuit and digital PLL system for phase tracking are obtainable and the original designing target of them have been hit.