2. A modem transmits a +2 voltage signal into a channel. The channel adds to this signal a noise term that is drawn from the set {0, 1, 2, 3} with respective probabilities {4/10, 3/10, 2/10, 1/10}. (a) Find the pmf of the output Y of the channel [5 marks]. (b) What is the probability that the output of the channel is equal to the input of the channel [5 marks] ? (c) What is the probability that the output of the channel is positive [5 marks] ? Solution