QUESTION

An analog sensor is used to monitor the temperature of sea water at different depth. The sensor is fitted to a buoy and incorporates a wireless transmitter that send a signal to a base station found on the mainland via a communication satellite as shown in Fig. 1. The effective range of the sensor is between 1 to 32 degrees Celsius with an operating bandwidth of 50 Hz. The transmitter converts the analogue sensor signal into a digital data stream using a PCM codec. The digital data stream is shift-keyed and then transmitted as an 16-FSK microwave signal with a carrier frequency at 1 GHz and frequency separation Δf_c of 10 MHz.

(a) Calculate the minimum sampling rate needed to fully characterize the analog sensor signal?

(b) Calculate the number of quantization levels configured in the PCM codec if we wish to detect 2 degrees Celsius changes in temperature.

(c) Calculate the bit rate in bps and the quantization error in dB of this PCM codec?

(d) Calculate the maximum signalling rate and data rate achievable using 16-FSK? 

(e) Calculate the bandwidth available for the microwave uplink?

(f) Calculate the maximum allowable SNRdB of the uplink if the data rate has to be a minimum of 350 Mbps?

(g) Now suppose that the above uplink becomes error-prone as well, what is the minimum signal power in dBW that is needed to sustain a data rate of 300 Mbps with a BER of 10^-5 at 20 degrees Celsius?