Solve the following problem:
The signal constellation for a communication system with 16 equiprobable symbols is shown in Figure. The channel is AWGN with noise power spectral density of N0/2.
1. Using the union bound, find a bound in terms of A and N0 on the error probability for this channel.
2. Determine the average SNR per bit for this channel.
3. Express the bound found in part 1 in terms of the average SNR per bit.
4. Compare the power efficiency of this system with a 16-level PAM system.