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Electronics => RF, Microwave, Ham Radio => Topic started by: beandigital on September 22, 2021, 07:50:21 am

Title: Anyone know what binary FSK modulated quadrature data is?
Post by: beandigital on September 22, 2021, 07:50:21 am

Someone asked me to design a demodulator for binary FSK modulated quadrature data. What exatly is this kind of modulation scheme? Thanks

Title: Re: Anyone know what binary FSK modulated quadrature data is?
Post by: srce on September 22, 2021, 09:45:04 am

If it's binary FSK, the signal shifts between two frequencies, one for a 0 bit the other for 1. The "quadrature data" part probably means that you will have I and Q data streams from your receiver.

Have a look at something like:

https://www.allaboutcircuits.com/technical-articles/digital-signal-processing-in-scilab-how-to-decode-an-fsk-signal/ (https://www.allaboutcircuits.com/technical-articles/digital-signal-processing-in-scilab-how-to-decode-an-fsk-signal/)
https://www.allaboutcircuits.com/technical-articles/how-to-use-i-q-signals-to-design-a-robust-fsk-decoder/ (https://www.allaboutcircuits.com/technical-articles/how-to-use-i-q-signals-to-design-a-robust-fsk-decoder/)

Title: Re: Anyone know what binary FSK modulated quadrature data is?
Post by: beandigital on September 22, 2021, 10:36:25 am

You are probably right. It was the quadrature part that threw me. Thanks