Rework Prob. 3-50 for the case of a multilevel polar NRZ line code when the number of levels is four.
Prob. 3-50
An analog signal is to be converted into a PCM signal that is a binary polar NRZ line code. The signal is transmitted over a channel that is absolutely bandlimited to 4 kHz. Assume that the PCM quantizer has 16 steps and that the overall equivalent system transfer function is of the raised cosine-rolloff type with r = 0.5.
(a) Find the maximum PCM bit rate that can be supported by this system without introducing ISI.
(b) Find the maximum bandwidth that can be permitted for the analog signal.