Response to the following problem:
Consider an MA communication system with K = 2 users and an AWGN channel. The receiver decodes the two signals by preforming SIC. The signal power levels for the two users at the receiver are P1 and P2.
a. Suppose that the receiver decodes the signal for user 2 and subtracts signal 2 from the received signal. Then the receiver decodes the signal from user 1 without interference. Determine the maximum rates that can be achieved by users 1 and 2.
b. Now suppose that P1 = 10P2 and that the signal from user 2 is decoded first. Determine the sum capacity of the two-user system.
c. Repeat part 2 if user 1 is decoded first, and compare the sum capacities in parts b and c.