EC2401 WIRELESS COMMUNICATION B.E ECE 7th Sem Nov Dec 2015 Question Paper

Looking for recent exam question paper of EC2401 WIRELESS COMMUNICATION ? You can here download the question paper contents of EC2401 WIRELESS COMMUNICATION, exam held in 02nd Nov 2015. It is 07th Semester B.E ECE Anna University Chennai Question Paper.

Anna University Chennai
Question Paper Code : 21467
B.E / B.Tech DEGREE EXAMINATION, NOVEMBER / DECEMBER 2015
Seventh Semester
Electronics and Communication Engineering
EC 2401/EC 71/10144 EC 701- WIRELESS COMMUNICATION
(Regulations 2008/2010)
(Common to PTEC 2401 - Wireless Communication for B.E. (Part-Time)
Sixth Semester - ECE - Regulations 2009)
Time: Three hours Maximum: 100 marks

Answer ALL questions.
 PART A - (10 x 2 = 20 marks)

1. Mention the operating frequency ranges for AMPS and ETACS systems.

2. Define mean excess delay and rms delay spread.

3. Define Co-channel Interference.

4. Define Coherence time.

5. What do you mean by Non-coherent Detection?

6. Draw the Constellation diagram of Binary Frequency Shift Keying system.

7. If a digital signal processing chip can perform one million multiplications per second, determine the time required between each iteration for the following adaptive equalizer algorithm LMS.

8. What is Transmit Diversity?

9. Draw the block diagram of a Direct Sequence Spread Spectrum Transmitter.

10. What is 18-95 Standard?

PART B - (5 x 16 = 80 marks)

11. (a) (i) With diagram explain Personal Access Communication system. (8)
(ii) Briefly explain ETACS System. (8)
Or
(b) (i) Explain some techniques intended to improve the coverage area and capacity of cellular system. (8)
(ii) Analyze co-channel interference and adjacent channel interference and suggest some measures to reduce them. (8)

12. (a) Derive the expressions for the total Electric field, Etot(d) and received power at distance, Pr(d) using two - ray ground reflection model. (16)
Or
b) The fading characteristics of a CW carrier in an urban area are to be measured. The following assumptions are made
(i) The mobile receiver uses a simple vertical monopole.
(ii) Large-scale fading due to path loss is ignored.
(iii) The mobile has no line-of-sight path to the base station
(iv) The pdf of the received signal follows a Rayleigh distribution
(1) Derive the ratio of the desired signal level to the rms signal level that maximizes the level crossing rate. Express your answer in dB. (5)
(2) Assuming the maximum velocity of the mobile is 50 km/hr, and the carrier frequency is 900 MHz, determine the maximum number of times the signal envelope will fade below the level found in (1) during a one minute test. (6)
(3) How long, on average, will each fade in (2) last? (5)

13. (a) Derive the expression for MSK signal as a special type of continuous phase FSK signal.
Or
(b) Explain in detail about the Gaussian Minimum Shift Keying (GMSK) Transmission and Reception with necessary diagrams.

14. (a) Explain in detail about Space diversity with necessary diagrams
Or
(b) Derive the LMS Algorithm for an Adaptive Equalizer.

15. (a) Explain in detail about various spread spectrum multiple access techniques with neat block diagrams.
Or
(b) Draw the basic arrangement of multitone OFDM transceiver and discuss its overall operation.

AU Chennai EC2401 Wireless Communication Nov Dec 2015 Important Questions

Looking for EC2401 Wireless Communication important questions to attend an exam on 02nd November 2015 ? You can here download the important question papers of Anna University Chennai. Provided here under is a collection of most frequently asked questions for the subject EC2401 Wireless Communication . This subject is present in the syllabus of B.E ECE Regulation 2008 of AU Chennai.

Anna University Chennai
Department of B.E  B.E Electronics and Communication Engineering
Seventh Semester
EC2401 Wireless Communication
November / December 2015 Exam Important Questions
(Regulation 2008)

See Also last 04 years Questions Papers of EC2401 Wireless Communication

1. (i) Discuss about the technical challenges faced by the wireless communication  (10)
(ii) What are the features of interference limited systems (6)

2. Explain the Principle of Cellular Networks and various types of Handoff Techniques (16)

3. (i) Explain the factors influencing small scale fading (10)
(ii) Find the average fade duration for thershold levels ? = 0.01, ? = 0.1, ? = 1, when doppler frequency is 200 Hz

4. Discuss the types of services, requirements, spectrum limitations and noise considerations of wireless communications (16)

5. (i) Explain how signal propagates against free space attenuation and reflection (8)
(ii) Discuss about temporal channel variations in Fixed Wireless Systems (8)


6. (i) Briefly explain the factors that influence small scale-fading (8)
(ii) If a transmitter produces 50W of power, express transmit power in units of dBM and dBW. If 50W is applied to a unity gain antenna with a 900 MHz carrier frequency, find the received power in dBM at a free space distance of 100 m from the antenna. What is Pz (10Km) ? Assume unity gain for the receiver antenna (8)

7. Explain with neat diagram the QPSK based transmission and reception technique and their significance in the wireless system (16)

8. Explain in details about,
(i) Linear Equalizers (8)
 (ii) Non Linear Equalizers (8)

9. Explain in detail about :
(i) Polarization Diversity (6)
(ii) Time Diversity (5)
(iii) Frequency Diversity (5)

10. Describe the principle involved in Cellular Code-Division-Multiple Access System