Abstract :
An acousto-optic technique for identifying and decoding various unknown types of digitally modulated signals is described. The performance of the system, which uses a bicell photodiode detector assembly, is modelled. It is shown that the output of the system, which consists of the sum and difference of the signals from the two bicell elements, is different and easily identifiable for each of the following modulation types: BPSK, QPSK, offset-keyed QPSK, differential QPSK, continuous-phase FSK (including MSK) and non continuous-phase FSK. Preliminary experimental results from an optical breadboard system are presented which are in good agreement with the modelled results
Keywords :
acousto-optical signal processing; continuous phase modulation; decoding; differential phase shift keying; frequency shift keying; identification; minimum shift keying; phase shift keying; quadrature phase shift keying; radio receivers; signal detection; surveillance; BPSK; MSK; QPSK; acousto-optic technique; bicell photodiode detector assembly; continuous-phase FSK; decoding; differential QPSK; digitally modulated signals; identification; model; noncontinuous-phase FSK; offset-keyed QPSK; optical technique; performance; surveillance receivers;
