(a) Which one of the four digital-to-analog conversion techniques (ASK, FSK, PSK or QAM) is most susceptible to noise? Explain your answer.
(b) Given the bit pattern 01001110, sketch the waveforms for NRZ-L, Bipolar AMI, Pseudoternary, Manchester and Differential Manchester encoding. Assume that the most recent preceding 1 bit for AMI has a negative voltage and the most recent preceding 0 bit for Pseudoternary has a negative voltage.
(c) PCM is based on the Nyquist Sampling theorem.
(i) State the Nyquist Sampling theorem.
(ii) A complex low pass signal has bandwidth of 200 kHz. What is the minimum sampling rate for this signal?
(d) What is the maximum data rate for a voice-grade line with a bandwidth of 4 kHz and a S/N ratio of 10000 to 1? Also, what is the maximum data rate if the S/N ratio is now enhanced to 50 dB?