Division Approximation In Fm Demodulator

Thanks kaz!!!But my I and Q singals have two complement form.Am i able to follow the procedure you mention above, or i have to change them into an other form.Something else by the term Msb you mean the last 16 bits of the number?So i scale the first one of the last 16 bits of the numerator until it goes from it's place to bit 31?All the arithmitic in my system is in two complement form...The singal being digitized by a an adc and has a two complement form.Then i multiply it with a sin and a cosine which have also two complement form.The coefficient of Fir filter are also in two complement form so I and Q have two complement form.In all these multiplications i truncate the result to Msb.

....by the way in similar discussion in another forum someone claim that i don't need the last division by I^2+Q^2 because as they said i measure angles not amplitude.

In fact, in a typical analog FM receiver, amplitude noise can mess up

reception of the signal so they clip the amplitude to remove the

noise.