1. The problem statement, all variables and given/known data A) Select uniquely decodable codes and instantaneous codes from Code1 to 5 of the image below: B) Personal question about second-order extension probabilites. If we have: probability of a symbol a P(a) = p1 probability of a symbol b P(b) = q1 Which is the probability of symbols aa, ab, bb of the second-order extension of the source? C) What is "rate"? 3. The attempt at a solution A) Uniquely decodable codes: 1,3,4,5 (in code 2 the extension(AE)=00100=extension(BA) ) Instantaneous codes: 1,4,5 (code 2 was not uniquely decodable, and in code 3 A is prefix of other codes) B) P(aa) = p1*p1 P(ab) = p1*q1 P(bb) = q1*q1 c) It depends on what it refers to: " Information rate R " : avg bits/symbol, R< Channel Capacity implies theoretical error-free transmission (Shannon) " transmission rate " : bits/time(sec) Is everything ok? Thanks in advance.