For a bit-rate of 8 Kbps, the best possible values of the transmitted frequences in a coherent binary FSK system are
a) 16 KHz and 20 KHz
b) 20 KHz and 32 KHz
c) 20 KHz and 40 KHz
d) 32 KHz and 40 KHz
Ans.d) 32 KHz and 40 KHz
The values of frequencies used for coherent PSK are
Fi=(n+1)/ Tb where n=1,2,etc
Given 1/Tb=8Kbps
So For n=3 ,Fi=(3+1)8=32Khz
and For n=4 ,Fi=(4+1)8=40Khz
Forum Expert
fi = nc + i /Tb
Given Rb = 1 /Tb = 8 kbs
f1 = [ 3 + 1]8 = 32 KHz
f2 = [4 + 1 ] = 40 kHz