PENENTUAN TIPE MODULASI DIGITAL MENGGUNAKAN TRANSFORMASI WAVELET DENGAN PENDEKATAN STATISTIK

Abstract

Nowadays, in the telecommunication world, the uses of wireless technology which most used is digital modulation technique. The technique which usually used are Phase Shift Keying (PSK), Frequency Shift Keying (FSK) and Quadrature Amplitude Modulation (QAM). Each of them has a characteristic and advantages. There is an effort to know every types of signal modulation, required a subsystem which able to classify the modulation types that used. In this final project, will be designed and tested a program which has a function to determine the types of digital signal modulation, they are BPSK, QPSK, FSK and QAM-16. The program of determination of digital signal modulation in this final project is made with MATLAB. The method are wavelet algorithms, they are Continuous Wavelet Transform and Discrete Wavelet Transform. The reference to determine the type of signal modulation is the variance from the wavelet transform. The testing will be done in the condition that the signal parameters is constant and also with variation of the signal parameters, they are SNR, bit data and amplitude of modulation signal. In addition, the sinus and cosines signals are used as strange signal. The results show that in ideal condition, the program is able to classify all the type of modulation signals better. The success ratio has reach 99% at SNR 10 dB. To get success ratio 100% for all signal, required minimal SNR 15 dB and to classify the unknown signals required minimal 11 dB to reach 100% success ratio. The testing with the change of the data bit, required minimal 32 bit to reach the success ratio above 90% for all the modulation types. The testing with the change of the amplitude of modulation signals, is obtained that the program was fail to classify BPSK, QPSK and FSK at the altering of the amplitude of modulation signals beside of 0.9 to 1.2. While the QAM-16 signal still can be classified well. Keywords: modulation, PSK