4. [3 marks) The (7,4) Hamming code takes four information bits (64b3 b2b) and adds three parity check bits (p3 P2 p) to give a codeword (C7 C6 C5 C4 C3 C2 C1) = (64 b3 b2 P3 b p2 p). The check bits (3 p2 p) are chosen as follows: P3 is chosen so as to give an even number of ls in the group (C7C6 C5 CA) = (64 63 62 P3); P2 is chosen so as to give an even number of ls in the group (C7 C6 C3 C2) = (64 b3 b1 p2); and P is chosen so as to give an even number of ls in the group (C7C5 C3 C) = (64 b2 b1 p). After transmission across a communications channel, a single error occurs in a transmitted codeword leading to the 7-bit string 1100111 being received. (a) [2 marks] Calculate the parity of each of the three code groups listed above for the received codeword 1100111 and use this to form the 3-bit syndrome (S3S281). (b) (1 mark] What was the codeword that was transmitted? Pare 20 of 31