An audio signal of BW that is equal to 4 KHz is sampled 25% above the Nyquist rate and is quantized. The maximum Q error is not to exceed 0.1% of the peak signal amplitude. The resulting quantized samples are coded and transmitted using 4-array signaling. a. Determine the minimum number of 4-ary pulses need to encode each samples b. Determine the essential transmission bandwidth for this signal such that there is no ISI at key samples of the pulses (at the values corresponding to half/center of pulse duration) 1. if NRZ rect() pulses are employed 2. if sinc() pulses are employed 3. if raised cosines with α =0.25 are put to use.