5. (Total=34%) The figure below depicts a scenario where two base stations transmit.
simultaneously the same Quadrature Amplitude Modulation (QAM) signal to a car
that is in the middle of two base stations and moves toward Base Station 2. The
signal is expressed as
in which f0 is the carrier frequency, p(t) is a rectangular pulse with the width
of T, and the amplitudes Ac and As can take on values from{±1, ±3}.
(c) (5%) Let the symbol error rate of QAM be approximated aswhere Q represents the Q function and γ is the SNR. To improve the symbol error rate from , roughly how much shall the SNR increase?