PROBLEMS SET III EXACT CALCULATION OF THE PROBABILITY OF ERROR Problem (1)* This problem investigates symbol error probability for a 4-ary communications scheme. In each case, the symbol constellation is modulated on a unit energy pulse shape and transmitted across a complex AWGN channel with spectral density No- a) Determine the symbol error probability for the constellation {-3A,-A, A, 3A} which is sketched as: do d 1 d2 d3 -3A -A A 3A b) Determine the symbol error probability for the constellation {0, 2A, 4A, 6A} which is sketched as: do d1 d2 d3 0 2A 4A 6A c) Comment on your results. Explain why the symbol error probability (SEP) in parts (a) and (b) are the same (if they are the same) or explain why one SEP is better than the other (if they are different)