Wireless Networks and Modulation Techniques Report

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WIRELESS - ASSIGNMENT -2

Contents
List of figures...................................................................................................................................3
1.......................................................................................................................................................4
a....................................................................................................................................................4
b...................................................................................................................................................4
c....................................................................................................................................................5
d...................................................................................................................................................5
e....................................................................................................................................................6
f....................................................................................................................................................7
g...................................................................................................................................................7
2.......................................................................................................................................................8
3.......................................................................................................................................................9
4.....................................................................................................................................................12
5.....................................................................................................................................................12
6.....................................................................................................................................................13
7.....................................................................................................................................................15
8.....................................................................................................................................................16
9.....................................................................................................................................................17
10...................................................................................................................................................17

Reference.......................................................................................................................................18
List of figures
Figure 1: Two level Amplitude Shift Keying..................................................................................4
Figure 2: Two level Frequency Shift Keying..................................................................................4
Figure 3: Two level Phase Shift Keying..........................................................................................5
Figure 4: Differential Phase shift keying.........................................................................................5
Figure 5: Four level Amplitude Shift Keying..................................................................................6
Figure 6: Four level Phase Shift Keying..........................................................................................7
Figure 7: Eight level Amplitude Shift Keying.................................................................................7
Figure 8: 16 QAF diagram.............................................................................................................12

1.
a.
Known binary data = 011010
Figure 1: Two level Amplitude Shift Keying

b.
Figure 2: Two level Frequency Shift Keying
c.
Figure 3: Two level Phase Shift Keying

d.
Figure 4: Differential Phase shift keying

e.
Figure 5: Four level Amplitude Shift Keying

f.
Figure 6: Four level Phase Shift Keying
g.
Figure 7: Eight level Amplitude Shift Keying

2.
We know that,
Frequency carrier (fc) = 500 kHz,
Frequency deviation (fd) = 25 kHz,
M= 16 (L= 4 bits)
Therefore, in order to calculate the frequency assignments (fa) for all the 16 possible
combinations of 4 bit data, we can use the formula-
fi = fc + (2i – L - M) * fd
Hence the fa of the 16 possible combinations is-
f1 = fc + (2i – L – M) * fd
 500 + (2 * 1.0 – 4 – 16) * 25 = 50.0 kHz.
Similarly, implementing the formula on all the frequencies, we get,
f2 = 100.0 kHz.
f3 = 150.0 kHz.
f4 = 200.0 kHz.
f5 = 250.0 kHz.
f6 = 300.0 kHz.
f7 = 350.0 kHz.
f8 = 400.0 kHz.
f9 = 450.0 kHz.

f10 = 500.0 kHz.
f11 = 550.0 kHz.
f12 = 600.0 kHz.
f13 = 650.0 kHz.
f14 = 700.0 kHz.
f15 = 750.0 kHz.
And, f16 = 800.0 kHz.
3.
MODULATION CAN BE TERMED AS THE process in which the characteristics of a wave is
changed so that it can be overlaid and transmitted as a message using the signals of higher
frequency.
From the given data, the frequency modulation can be defined as
Yfm (1) = Ec.Cos (2πfct + 2πtf ∫
0
t
x (t )dt)
1. fm = fc - ∆f (more separation due to low frequency)
2. fm = fc + ∆f (less separation due to high frequency)

The amplitude modulated signal can be defined as
y (t) = (Ac + m(t)) sin Wc.t