COMP4336/9336 Mobile data networking PHY Fundamentals I Solved

Description

Q1. What is the wavelength of a signal operating at the frequency of

2. 4 GHz
3. 2 GHz
4. 5 GHz
5. 8 GHz
6. 300 GHz

Q2. What is the frequency of a signal having a wavelength of

1. 1 meter?
2. 50 cm?

Q3. Represent the following powers in dBm:

1. 100 kW
2. 500 mW
3. 5 mW
4. 1 mW
5. 100 pW

Q4. Represent the following powers in dBW:

1. 1 kW
2. 100 mW
3. 1 µW
4. 1 nW
5. 1 pW

Q5. How many Watts of power is

1. 30 dBm?
2. 10 dBm?
3. 30 dBW?

Q6. Received signal strength is measured at 10 mW. What is the noise power in dBm, if SNR = 10 dB?

Q7. A telephone line is known to have a loss of 20 dB. The input signal power is measured at 1 Watt, and the output signal noise level is measured at 1 mW. Using this information, calculate the output signal to noise ratio in dB.

Q8. What is the maximum data rate that can be supported on a 10 MHz noise-less channel if the channel uses eight-level digital signals?

Q9. What signal to noise ratio (in dB) is required to achieve 10 Mbps through a 5 MHz channel?

Q10. Compute the average Doppler frequency shift at 36 km/hr using 3 GHz band. What is the Doppler spread?  What is the channel coherence time?