BPSK demodulation

[smokingRooster]

Hi everyone,

I'm doing a project which requires me to demodulate a BPSK signal. To do so I first need to multiply the incoming signal with a sin and cos wave that has the same frequency as the carrier. My plan is to store the incoming signal from the ADC in an array and multiply each element with a locally generated sin/cos wave. However I'm not sure if I can generate the sin/cos waves locally and store them somewhere. Would AudioSynthWaveform achieve that?

Thank you in advance

 

[tni]

You want a lookup table in flash, right (content generated at compile time)?

 

[Theremingenieur]

if not, a real-time quadrature oscillator in software, emulating a state variable filter with infinitely high Q is a three liner in C...

 

[PaulStoffregen]

However I'm not sure if I can generate the sin/cos waves locally and store them somewhere. Would AudioSynthWaveform achieve that?

Certainly AudioSynthWaveform can generate sin/cos waveforms. But it generates them in real time. There is no "store them somewhere".

To use this, you'd create two AudioSynthWaveform objects configured as sine waves and use the phase() function to get them 90 degrees apart. See this right-side-panel documentation, and notice the mention of using AudioNoInterrupts to make sure both phase settings are applied at the same moment.

https://www.pjrc.com/teensy/gui/?info=AudioSynthWaveform

As for "multiply each element", perhaps the AudioEffectMultiply object can help?

https://www.pjrc.com/teensy/gui/?info=AudioEffectMultiply