Re: ASK and FSK
hey,
regarding the question, i have a reply from an expert whose explanation is as below.
FSK consists of two carrier frequencies. The frequency changes depending on the symbol 1 or 0 used. Mathematically can be described as:
s(t) = f1(t) (2*pi*fc1*t +phase) + f2(t) (2*pi*fc2*t +phase)
So, in power spectrum, there are two signals f1(t) and f2(t)
ASK is amplitude modulated signal which the amplitude changes depending on the symbol 1 and 0 used. Mathematically can be described as:
s(t) = f(t) (2*pi*fc*t +phase)
So, in power spectrum, there is only one signal f(t)
If a signal is transmitted with FSK TX, and received with an ASK RX, you will lose some information. ASK RX only care about one frequency and looking for the amplitude change (using envelop detector) in the signal. As a result, if the signal received is more than 1 frequency, it will be rejected.
ASK and FSK are different modulation scheme. As far as I know, you can't use FSK TX and expect ASK RX to recover the information.
Dear biff44,
can you explain further, i couldn't get you...