What are the three basic propagation mechanisms ?Explain each of them.

(b) Why is path loss model required in wireless communication ?Explain log-normal path loss model.

2.(a) Differentiate between FDMA, TDMA and SDMA techniques.

(b) Explain the various types of diversity techniques in wireless communication system.

3.(a) What are Vocoders Explain channel vocoders in detail.

(b) Compute theRMS delay spread for the following power delay profile:

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4.(a) Define frequency reuse concept. HOw is it used to increase cellular system. capacities Explain with suitable example.

(b) What are the different methods used for minimization of co-channel and adjacent channel interference?

5.(a) Write down the different features of2G and 3G wireless systems. Name some wireless standards used around the world under second generation of wireless system.

(b) A receiver is located 10 km from a 50 W transmitter. The carrier frequency is 900 MHz, free space propagation is assumed, Gt and Gr =2. Find
the power of the receiver

(ii) the magnitude of E-field at the receiver antenna.

6.(a) Consider a transmitter which radiates a sinusoidal carrier frequency ,of 1850 MHz. For a vehicle moving at 60 mph, compute the received carrier freQuency, if the mobile is moving directly towards the transmitter

(ii) directly away, from the transmitter

(iii) in a direction which is perpendicular to the direction of arrival of the transmitted signal.
Draw and explain the working of Linear Predictive Coders(LPC).

7. Write short notes on any two of the following RAKE Receiver, DS-SS Impulse response model and parameters of multipath channels