Assignment 3
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Transcript of Assignment 3
MANIPAL INSTITUTE OF TECHNOLOGY(A constituent college of Manipal University, Manipal)Manipal Karnataka 576 104
Year : B.Tech VI Sem Exam : 3rd Assignment Max. Marks: 2 Time: 25 MinutesSub: Mobile Communications (Program Elective)
1. Discuss the various types of small-scale fading.
2. Explain about Rayleigh and Ricean Fading distribution functions.
3. Assume a discrete channel impulse response is used to model urban RF radio channels with excess delays as large as 100 s and microcellular channels with excess delays no larger than 4 s. If the number of multipath bins is fixed at 64, find (a) (b) the max. RF BW which the SMRCIM models can accurately represent.Repeat the problem for an indoor channel model with excess delays as large as 500 ns.NOTE: Quantizing the delay bins determine the time delay resolution of the channel model, and the channel model used to analyze Tx RF signals having BWs < 2/
4. Given Power Delay Profile is
When You will have flat fading, when You will have Frequency selective fading?
5. Explain the following parameters: i) Mean Excess Delayii) RMS delay spread iii) Max. Excess Delay (X dB) iv) Coherence Bandwidth (Bc) v) Coherence Time (TC)
6. Assume aa MS traveling at a velocity of 10 m/s receives two multipath components with fc =1000 MHz. The 1st component arrived at = 0 with an initial phase of 0 and a power of -70 dBm, and the 2nd component which is 3 dB weaker than the 1st component was arrived at = 1s, also with an initial phase of 0, If the MS moves directly towards the direction of arrival of the 1st component and directly away from the direction of arrival of the 2nd component, compute the narrowband instantaneous power at time intervals of 0.1 sec from 0 sec to 0.5 sec.
i) Compute the average narrowband power received over this observation interval.ii) Compare average narrowband and wideband received powers over the interval.
Assume that the amplitudes of the two multipath components do not fade over the local area.
7. Derive the relation between Bandwidth and Received Power of wideband and narrowband signals in a small-scale fading channel.
