1. No category

EKT450
There are 3 assignments for EKT450 which carry
10%.
• Guideline
1) Assignment 1 carry 3%,
2) Each assignment must be submitted
individually,
3) Dateline for assignment 1 is 3rd April 2015.
1
Assignment 1 (a) – Q1
Discuss the evolution of technology networks from
2G to 4G and beyond (5G). For the future 5G
network, state your opinion on:
i.
Spectrum for 5G,
ii. Machine-to-machine communication,
iii. Technology impact on user’s safety and
health.
2
Assignment 1 (a) – Q2
Assume a mobile station is located 15km from a
40W transmitter. The carrier frequency is 900 MHz,
free space propagation is assumed, Gt = 0 dB and
Gr = 5 dB.. Find (a) the power at the receiver, and
(b) the magnitude of the E-field at the receiver
antenna.
3
Assignment 1 (a) – Q3
If a particular modulation provides suitable BER performance
whenever στ / TS ≤ 0.1, determine the smallest symbol period TS
that maybe sent through RF channels in (a) indoor and (b)
outdoor, without using equalizer. Estimate the 90% and 50%
correlation coherence bandwidth for both channels.
Pr (τ)
Pr (τ)
(b) outdoor
(a) indoor
0 dB -
0 dB -
-10 dB -
-10 dB -
-20 dB -
-20 dB -
-30 dB -
-30 dB -
0
50
75
100
τ (ns)
0
5
10
τ (μs)
4
Assignment 1 (a) – Q4
Path Loss and Fading (Large Scale)
A BS of 30m height is operating at 900 MHz and transmits 20W power.
The transmitter and receiver antenna gains are 6dB and 2dB
respectively. A MS of 2m height is located at 5km from the BS. If other
losses is 5dB and fading =6dB due to log-normal fading, compute and
compare the minimum power received by the MS in dBm if the
following propagation models are used:
(i)
Free space propagation loss, FSPL
(ii)
Plane earth propagation loss, PEPL
(iii)
log-distance with do=1km, =4 and PL(do)=FSPL, and
(iv)
diffraction model if an obstacle of 30m height is located at 2km
from the BS
Comment on the practical minimum power received by the MS due to
the presence of obstacle in (iv).
5
Assignment 1 (a) – Q5
Path Loss and Fading (Small Scale)
A power delay profile measured at 900 MHz is shown in Figure
below.
i. Calculate the root-mean square delay spread and mean
excess delay for the channel.
ii. If the channel is to be used with a modulation requires an
equalizer whenever the symbol duration, TS is less than 10στ,
suggest the maximum radio frequency symbol rate that can be
supported without requiring an equalizer.
iii. If a mobile station travelling at 30
km/hr receives a signal through the
channel, evaluate the time over which
the channel appears stationary.
6