Answer Happy

Question 2 (24 marks) A full-scale audio signal is sampled at the Nyquist sampling rate and then applied to a 4-bit Midriser with the dynamic range from -4 V to 4 V. The audio signal has a constant power spectral density of 0.5 W/kHz, and its peak-to-rms ratio, i.e., the ratio of the peak amplitude to the square root of signal power, is measured to be 3 dB. 1. Determine the step size, the maximum quantization error, the quantization noise power, and the number of quantization levels of the Midriser. (4 marks) 2. Determine the output bit sequence of sampled values (-0.18 V, 1.61 V, 2.12 V) using Gray coding. Show your detailed steps, including the quantized values assigned to each sample. (6 marks) 3. Determine the SQNR in dB. (5 marks) 4. Determine the bit rate of the bit stream. (4 marks) 5. Suppose that 10 such audio signals, each sampled, quantized and modulated, are sent to a central station with time-division multiplexing (TDM) over a channel with frequency range of [0, 200 kHz). What modulation scheme should be adopted to ensure 90% in-band power? State your reason. (5 marks)