Question 1 was marked out of 4:
marks were awarded as follows:
- 1 for figuring out the symbol rate for no-ISI
- 1 for computing the bit rate (relative to answer above)
- 1 for computing required SNR, 1 for computing the corresponding noise power
Question 2 was marked out of 4:
marks were awarded as follows:
- 1 for looking up the right bit values and using them in the correct order
- 1 for correctly doing the Manchester encoding and drawing the waveform
- 1 for correctly calculating the min/max time durations
- 1 for correctly computing the bit rate
Question 3 marked out of 5
marks were awarded as follows:
- 1 for the right generator polynomial in bits
- 1 for deciding to divide by G(x) or for re-computing the CRC
- 2 for correct remainder or CRC calculation
- 1 for right conclusion (no error)
Question 4 marked out of 5
marks awarded as follows:
(a) 1 mark for computing the data/ack durations in bits,
1 mark for computing the data/ack durations in ms
(b) 2 marks for throughput calculation (1 for total time, 1 for throughput)
(c) 1 mark for mentioning go-back-N and selective-repeat (1/2 mark if only one)
Question 5 marked out of 2:
- 1 mark for a correct answer to each part
Question 6 marked out of 5:
(a) 1 mark for correctly computing the number of data and parity bits
(b) 1 mark for correctly computing n and k
(c) marked as follows:
1 mark for computing all four hamming distances (not just one)
1 mark for choosing the correct codeword
1 mark for the number of errors corrected
Question 7 marked out of 5:
marks as follows:
- 1 per correct answer, 0.5 if answer partially correct