Question (3) A channel encoder maps blocks of two bits to seven bit (channel) codewords. The four possible codewords are 0111, 1011, and 1100. A codeword is transmitted over a BSC whose crossover probability p 0.4. Suppose the receiver observes y = [ 1001 ) at the output of the BSC Note: &map(Y) = arg max()" p(x) , &mL (Y) = arg max")"wy) a) Assume that all four codewords are equally likely to be transmitted. Given the observed y = ( 1001 ] at the receiver, what is the most likely codeword that was transmitted? b) Assume that the codewords are not equally likely. Their prior probabilities are 0.2, 0.3, and 0.5, respectively. Given the observed y = [ 1001 ] at the receiver, what is the most likely codeword that was transmitted? C) Assume that all four codewords are equally likely to be transmitted. Given the observed y = [1001 ] at the receiver, what is the most likely codeword that was transmitted if we change the crossover probability p 0.72 = Dararan