Question 7 [10 Marks] A digital communication system transmits quadrature amplitude modulation (QAM) signal over a voice-band telephone channel at a rate 1200 symbols/second. If the signal is purported by additive white Gaussian noise, a) [6 Marks] At what bit energy to noise power ratio, an error probability of 105 is achieved at the following bit rate? i) 2400 bps ii) 4800 bps Hint: Use Q(4.2649)-105 Q: Q-Function b) [4 Marks] Compare and discuss the results obtained in part (a) in terms of bit energy to noise power ratio.