Question:
a) How many bits per second can be sent on a noiseless 4 MHz channel if four-level digital signals are used?
b) If a binary signal is sent over a 3 KHz channel whose SNR is 30 dB, what is the maximum achievable data rate?
c) A modem constellation diagram has data points at the following coordinates: (1,1), (1,-1), (-1,1) and (-1,-1). How many bits per second can a modem with such parameters achieve at 2400 baud?
d)
i) Using an example, explain how CRC is used for error control.
ii) A 50 Km long cable runs at the T1 data rate (1.544 Mbps). The propagation speed in the cable is 200 m/µs. How many bits fit in the cable?
e) Sketch the differential Manchester encoding for the following bit stream: 0011101