railway RRB JE (CBT I + CBT II) Mock Test 2024 Communication Systems Baseband Transmission Signal Constellation
A binary symmetric channel with p as transition probability, users repetition code ‘n’ times, with n = 2m + 1 being an odd integer. In a block of n bits, if the number of zeros exceed number of decoder decodes it as ‘0” otherwise as “ 1”. An error occurs when m + 1 or more transmissions out 3 are incorrect. What is the probability of error?
1
3p2 (1 –p) +p3
2
5p2 (1 –p) +(1/3)p3
3
2p (1 –p) +p2
4
p3 (1 –p) +p2