Consider the octal signal point constellations in Figure P3.4. 1. The nearest-neighbor...

Consider the octal signal point constellations in Figure P3.4.

1. The nearest-neighbor signal points in the 8-QAM signal constellation are separated in distance by A units. Determine the radii a and b of the inner and outer circles, respectively.

2. The adjacent signal points in the 8-PSK are separated by a distance of A units. Determine the radius r of the circle.

3. Determine the average transmitter powers for the two signal constellations, and compare the two powers. What is the relative power advantage of one constellation over the other? (Assume that all signal points are equally probable.)