SIGNAL DEMODULATOR OF SIXTEEN-POSITION SQUARE-LAW ON-OFF KEYING Russian patent published in 1994 - IPC

FIELD: radio engineering. SUBSTANCE: demodulator uses two attenuators, 1, 2, solver 3, six adders 4 through 9, two phase detectors 10, 11, whose second inputs are connected to the inputs of the demodulators, and their outputs via series-connected first low-pass filter 12, first multiplier 13, second low-pass filter 14 and second multiplier 15 are connected to the first and second inputs of first adder 4 respectively. The demodulator has two quantizers 16, 17, whose inputs are connected to the outputs of first and second low-pass filters 12, 14 respectively, loop filter 18 connected via controlled oscillator 19 directly to the first input of first phase detector 10, and to the first input of second phase detector 11 via phase shifter 20. The inputs of solver 3 are connected to the outputs of quantizers 16, 17, and the outputs - to the demodulator outputs. The first outputs of first and second quantizers 16, 17 are connected to the first inputs of second and third adders 5, 6 respectively. The second outputs of first and second quantizers 16, 17 via first and second attenuators 1, 2 are connected respectively to the second inputs of second and third adders 5, 6, whose outputs are connected to the second inputs of the first and second multipliers respectively. The first outputs of first and second quantizers 16, 17 are connected to the first and second inputs of fourth adder 7 respectively. The outputs of first and second attenuators 1, 2 are connected respectively to the first and second inputs of fifth adder 8, whose output is connected to the input of third multiplier 21, whose other input is connected to the output of fourth adder 7. The output of third multiplier 21 is connected to the first input of sixth adder 9, whose second input is connected to the output of first adder 4, and the output - to the input of filter 18. The first input of the first adder and the second inputs of the second, third and fourth adders are inverting ones. EFFECT: enhanced reliability. 3 dwg