Mobile Communication - Dec 2011

Electronics Engineering (Semester 8)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks. 1 (a) Compare SDMA,TDMA,FDMA and CDMA mechanism(5 marks) 1 (b) Explain mobile assisted soft handoff procedures in CDMA based secular system (5 marks) 1 (c) Explain data oriented CDPD network(5 marks) 1 (d) What is meaning of traffic channel, signaling channel, broadcast channel & common Control channel w.r.t. G.S.M(5 marks) 2 (a) Assume a receiver is located 10 km from a 50 W transmitter. The carrier frequency is 900 MHz, free space propagation is assumed, Gt=1, and Gr=2, find (a) the power at the receiver, (b) the magnitude of the E-field at the receiver antenna, (c) the rms voltage applied to the receiver input assuming that the receiver antenna has a purely real impedance of 50 and is matched to the receiver(10 marks) 2 (b) Explain free space propagation model.(10 marks) 3 (a) Draw the block diagram and explain GSM architecture in details indicating all the interfaces.(10 marks) 3 (b) Explain the frequency and channel specification of IS-95(10 marks) 4 (a) Explain forward link features of CDMA 2000 and also explain basic services provided by upper layer of CDMA 2000(10 marks) 4 (b) Describe open loop and closed loop system of power control in a CDMA system(10 marks) 5 (a) Give the technical differences in W-CDMA and CDMA-200(10 marks) 5 (b) Write short note on any two path loss models(10 marks) 6 (a) Explain in details signaling protocol architecture used in GSM(10 marks) 6 (b) Explain Handoff and power control in 3G system(10 marks)

Write short notes on :-

7 (a) Rake receiver(5 marks) 7 (b) Security algorithms in GSM(5 marks) 7 (c) Raleigh and Rican distribution(5 marks) 7 (d) Improving coverage and capacity in cellular system(5 marks)