9. Consider an 1800 MHz mobile radio system for cellular communication. The base station is at a height of 3 m above the ground and the mobile at 1 m. The gain of the base station antenna is 6 dBi and for the mobile antenna, the gain is 2 dBi. It is required to determine the minimum transmitted power in order for the BS to serve a mobile at a distance of 1000 m in a Line-of-sight communication link. The received power is -104 dBm.

5. For FM signal modulation, if the amplitude of carrier signal is 45 Volts, carrier frequency is 10 MHz, frequency of the modulating signal is 1 kHz, modulation index is 0.9. what will be the equation of the modulated signal, sensitivity of and bandwidth of the FM signal.

6. Draw the constellation diagram of 16-QAM. How many bits are sent in one symbol in 16-QAM. How much the increase in data rate if 16 QAM is replaced by 64QAM (in 96age).

7. Geostationary satellites use L, C, Ku and Ka bands. The path length from an earth station to the GEO satellite is 39,200 km. For this range, calculate the path loss in dB for the following": Note: Round all results to nearest 0.1 dB. i) 1.7 GHz, ii) 1.9 GHz

8. Consider a TDMA communication system where the forward link is allocated with a total bandwidth of 30 MHz, each radio channel is of 200 kHz, if the number of channels are 12 and no guard band is assumed, calculated the number of users. In the second case, if there is the guard band of 25 kHz is inserted in the design, what will be the maximum number of users?

9. If a GSM timeslot consists of 6 trailing bits, 8.25 guard bits, 26 training bits, and 2 traffic bursts of 58 bits of data. Find the total number of bits in each time slot. If a frame has 8 slots, find the total number of bits in each frame, also calculate overhead bits in each frame and frame efficiency.

6.2-6 A duobinary line coding proposed by Lender is also ternary like bipolar. In this code, a 0 is transmitted by no pulse, and a 1 is transmitted by a pulse p(t) or -p(1) according to the following rule. A I is encoded by the same pulse as that used for the previous 1 if there are an even (including zero) number of Os between them. It is encoded by a pulse of opposite polarity if there are an odd number of Os between them. Like bipolar, this code also has single-error-detection capability, because correct reception implies that between successive pulses of the same polarity, an even number of Os must occur, and between successive pulses of opposite polarity, an odd number of Os must occur. (a) Using half-width rectangular pulse, sketch the duobinary signal y() for the random binary sequence 010110100010010... (b) Determine Ro, R₁, and R₂ for this code. (c) Show that R=0. n>2 for this code. (d) Find and sketch the PSD for this line code (using half-width rectangular pulse). Show that its effective bandwidth is Rb/2 Hz and is only half of the bipolar linecode bandwidth, independent of the pulse shape.

7.1-14 A binary source generates digits 1 and 0 randomly with probabilities P(1)=0.8 and P(0) = 0.2. (a) What is the probability that exactly n-2 1s will occur in a n-digit sequence? (b) What is the probability that at least three Is will occur in an-digit sequence?

(a) Show in frequency domain whether this pulse satisfies Nyquist first criterion for zero ISI. (b) Confirm the result of (a) in time domain. (c) Using this pulse in polar baseband transmission, determine the approximate channel bandwidth required for bit rate of 512 kbit/s.

6.3-4 A video signal has a bandwidth of 4.5 MHz, average power of 0.8W, and peak voltages of +1.2 V. This signal is sampled, uniformly quantized, and transmitted via binary polar baseband modulation. The sampling rate is 25% above the Nyquist rate. (a) If the required SNR for video quality is at least 53 dB. determine the minimum binary pulse rate (in bits per second) for this baseband transmission. (b) Find the minimum bandwidth required to transmit this signal without ISI when a raised-cosine pulse shape with roll-off factor r=0.3 is used.