Problem 1:

(a) 5 points.  1 for understanding the summation (which terms to
include, etc.).  1 point for each of the 3 plots.  1 for a 1-2
sentence comparison of the plots.

(b) 2 points for understanding which terms to include.  1 point for the
plot.  2 points for comparison with previous signal.

Problem 2:

5 points for each part.  In each part, correct use of Shannon's formula fetches
2 points, correct setting of the parameters 2 points, and final
calculation 1 point.

Problem 3:

5 points for each part.  In each part, correct use of path loss
formula fetches 2 points, correct setting of the parameters 2 points,
and final calculation 1 point.

Problem 4:

2 points for correct use of Shannon's capacity formula, 2 points for
correct calculation of noise, and 1 point for final calculation.

Problem 5:

2 points for correct application of formula, 2 points for correct
setting of parameters, and 1 point for final calculation.  (No need to
give final answer in dB.)

If a student only applies one of the two multipliers (0.56 or 0.50 for
efficiency), still give them full credit, since the wording was a bit
confusing.
 
Problem 6:

5 points each part.

First part.  Calculation of gain 3 points.  Final calculation of
radiated power 2 points.

Second part.  Correct application of path-loss formula 2
points. Correct setting of parameters 2 points. Final calculation 1
point.