6. A BPSK based communication system uses

(a) -0.01
(b) 0.01
(c) 0.63
(d) 0.97

Answer: d. 0.97

7. A BPSK based communication system uses the equiprobable symbols +10 and -10 to transmit over an additive white Gaussian noise channel. The value for a symbol at the receiver is 0. What is the optimal decision on the transmitted symbol if the receiver receives 0?

(a) +10
(b) -10
(c) 0
(d) Cannot decide between +10 and -10

Answer: d. Cannot decide between +10 and -10

8. For ISI-free signaling at the same data rate, which of the following pulse shapes uses the least bandwidth?

(a) rect
(b) sinc
(c) ramp
(d) RRC with 100% excess bandwidth

Answer: b. sinc