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Altera_Forum
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10 years ago

phase detection am signal

Hi, i've implemented, in VHDL language, an iq demodulator for AM signal with the classic method of multiplying the input signal by sine and cosine, low pass filter and then SQRT(I^2 + Q^2). N...
Altera_Forum's avatar
Altera_Forum
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10 years ago

The first two signals are on off keying OOK (a simple form of amplitude modulation).

The third signal seems as phase modulated BPSK (Not AM)

For OOK you need to read amplitude if it is well away from zero. In fact you don't need to square root (I^2+Q^2).

For BPSK you need to map output of demod to I constellations, there will be 180 degrees ambiguity of phase but this can be dealt with by using known data pattern from transmitter.