B.TECH - Semester 8 wireless communication Question Paper 2019 (nov)
Practice authentic previous year university questions for better exam preparation.
Sample Questions
- How the pagers are identifying the required messages?
- List the types of codeless telephones and describe briefly about each one.
- Why the performance of Bluetooth technology has improved by adopting frequency hopping?
- How the probability of blocked calls $\left(\mathrm{P}_{\mathrm{r}}\right)$ can be computed from traffic intensity $\left(\mathrm{A}_{\mathrm{u}}\right)$ ?
- Give the features of GSM standard for cellular mobile communication.
- Why Doppler spread and Coherence time are important for a multipath wireless channel?
- Explain the diffraction of radio wave signals.
- Why the OFDM system provides best solution for wireless transmission? Give the reasons.
- Give the impacts of mutual coupling of antenna arrays.
- What is a geo-stationary satellite? ( $\mathbf{1 0} \boldsymbol{\times} \mathbf{2} \boldsymbol{=} \mathbf{2 0}$ Marks)
- (a) Give the protocol stack for implementing Zig-bee wireless system for low power application and give functions of each layer.
- (b) Discuss the evolution of wireless mobile communication system. OR
- (a) How the Wireless Local Area Network (WLAN) has implemented with different standards? Describe briefly.
- (b) Give the architecture of a modern cellular system for reliable communication and briefly describe the functions of each module.
- (a) Explain about different channel assignment strategies used in cellular systems.
- (b) If a Signal to Interference Ratio (SIR) of 30 dB is required for satisfactory forward channel performance of a cellular system, what is the frequency re-use factor(Q) and cluster size(N) that should be used for maximum capacity with path loss exp...
- (i) $\mathrm{n}=4$ and (ii) $\mathrm{n}=3$ ? Assume that there are 6 co-channel cells in the first tier and all of them are at the same distance from the mobile. Use the suitable approximation from the table Cluster size(N) Co-channel re-use ratio(...
- (a) Draw the diagram of a cellular call setup system and explain how a cellular telephone call is made between the landline and the mobile user, when the call is initiated by the landline customer. Explain with the help of a timing diagram,
- (b) Give suggestions for improving the capacity and coverage of the cellular system.
- (a) Derive expression for different propagation parameters with reference to Clarke's model for flat fading channel. How the Doppler spread affect the Clarke's model?
- (b) How the MIMO system improves the efficiency of wireless transmission? Describe about narrowband MIMO model with the help of necessary diagrams.
- (a) Consider a transmitter which radiates a sinusoidal carrier frequency of 1900 MHz , for a vehicle moving with a speed of 50 mphr , compute the received carrier frequency if the mobile is moving,
- (i) Directly towards the transmitter (ii) Directly away from the transmitter (iii) In a direction which is perpendicular to the direction of arriving transmitted signal.
- (b) What are the factors which influencing the Small-Scale Fading in wireless channels?
- (a) Give the block diagram for a typical earth station transmitter and receiver of a satellite communication system and explain about each block.
- (b) Briefly discuss about different traffic routing methods for wireless communication.
- (a) Briefly discuss about the given multiple access system with necessary diagrams.
- (i) Time Division Multiple Access (TDMA) (ii) Frequency Division Multiple Access (FDMA) (iii) Space Division Multiple Access (SDMA)