1. Numericals

2. A cellular mobile communication system is operating at the carrier frequency of 900 MHz. The cell radius is R = 2.5 km. A mobile unit is located at the edge of a cell. For what percentage of time the received signal power by this mobile unit is greater than –70 dBm?
Assume the following: The close-in reference distance d0 = 1 km (the propagation loss until the close in reference distance is open space propagation loss). Transmitter power Pt = 10W, the receiver and the transmitter antenna gains are Gt=3 dB and Gr=0 dB, respectively. The propagation beyond the close-in distance occurs with a path loss exponent n=4 and follows a log-normal distribution with standard deviation =6.5dB.

3. A transmitter provides 10 W to the transmitter antenna having 12 dB gain. The receiver antenna has a gain of 3 dB and the receiver bandwidth is 200 kHz. The receiver noise figure is 8 dB and the carrier frequency is 900 MHz. Determine the minimum number of cells that can ensure an SNR of 20 dB provided for 95% of the time in Islamabad City. The area of Islamabad City is 906 km2 and the average temperature in Islamabad is 27 o C. Assume the path loss exponent n=4, the close-in reference distance d0=1 km and the log-normal shadowing standard deviation =8 dB.

4. Determine the number of omni-directional cells required to cover a 1000 sq. km area cellular mobile system at 900 MHz. Assume the sensitivity of cellular mobile receivers is equal to -100 dBm, the close-in reference distance d0=1 km, transmitter power Pt=1W, the receiver and the transmitter antenna gains are Gt=Gr=2 and the path loss exponent n=4. Assume that the propagation loss until the close in reference distance is in fact open space propagation loss.

5. A transmitter provides 1 W to the transmitter antenna having 12 dB gain. The receiver antenna has a gain of 3 dB and the receiver bandwidth is 200 kHz. The receiver noise figure is 8 dB and the carrier frequency is 900 MHz. Determine the radius of the cell that can ensure an SNR of 20 dB provided for 90% of the time. Assume the path loss exponent n=4, the close-in reference distance d0=1 m and the log-normal shadowing standard deviation =8 dB. The average temperature in the region remains at 27 o C.