Paper 1, Section I, G
Part II, 2017
Let be a binary code of length . Define the following decoding rules: (i) ideal observer, (ii) maximum likelihood, (iii) minimum distance.
Let denote the probability that a digit is mistransmitted and suppose . Prove that maximum likelihood and minimum distance decoding agree.
Suppose codewords 000 and 111 are sent with probabilities and respectively with error probability . If we receive 110 , how should it be decoded according to the three decoding rules above?