The effect of changing a on the time
domain response of the data signal is readily seen from the eye diagram. As a is reduced, the eye opening dramatically narrows, requiring the
accuracy of symbol timing to be even more exact. Additionally,
it can be seen that the overshoot of the pulse caused by the filtering is
greater for small a, increasing the peak to mean ratio of the
energy in the data signal, and hence the peak signal handling requirement of the modulator
and demodulator circuits.
|