Design And Implementation Of Emergency Positon Indication Radio Beacon Tester

Emergency position indicating radio beacon(EPIRB)system is necessary to be equipped on medium-sized vessels.EPIRB can protect the safety of the vessel and ensure the vessel to get emergency relief as quickly as possible when it in distress.EPIRB has been widely equipped in the field of maritime rescue.Its routine maintenance and working state detection is the key to protect the safety.In this subject,I propose a design scheme of EPIRB tester through analyzing the performance of existing commercial tester and combining with the specifications demand of EPIRB tester.And I achieve the highly precision measurement of EPIRB signal's carrier frequency and the protocol analysis functions.First of all,I introduce the theoretical basis of EPIRB tester briefly,do principle analysis and numerical simulation on digital down converter,numerically controlled oscillator and filter design,which are applied in EPIRB tester.Also I analyze and simulate the demodulating arithmetic of dual phase L modulated signal and BCH decoding method.Secondly,the existing carrier frequency measurement methods are analyzed and compared according to the design specifications of EPIRB tester.A measurement method about carrier frequency is proposed and implemented,which is combined FFT with Costas loop.The MATLAB simulation results of frequency measurement precision and tracking speed demonstrate the feasibility of this method.Finally,the new design scheme of EPIRB tester is given,including RF front-end signal processing module,FPGA digital intermediate frequency processing module,PC communication module and other functional modules.I produce and implement each module.Experiment results show that each module can complete their tasks and coordinate the work to measure the EPIRB signal parameters.The designed EPIRB tester achieves its technical requirements and I complete the design task.