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8/11/2019 A Study of the Communication Channels and of Noise Sources
http://slidepdf.com/reader/full/a-study-of-the-communication-channels-and-of-noise-sources 1/18
The study of the communication channel and of noise sources
I1.The block scheme in the case of “uniform random demo“:
UniformMux
Mean
& var
Graph[.5 1/12]
Expected value
The first device is uniform noise generator which generates uniformly distributed noise
between the lower and the upper bounds. The following device has at its output therunning mean to 1
st out-port and running variance to 2
nd out-port. The third block has as
output a constant(0.51/12) . The mux combines all the three input signals into larger
vectors.The graphs for different values of the sampling time:
sample time=0.1s sample time=1s sample time=5s.
I2.The block scheme for “Gaussian random demo”:
Mux
Mean
& stdGaussian
[0 1]
Expected value
The 1st block generates a Gaussian distributed noise with given mean and given variance.The mean is 0 and the variance is 1. The 2
nd block has at its output the running mean to
1st out-port and running standard deviation to 2
nd out-port. The 3
rd block has as output a
constant [0 1] . The mux combines all the three input signals into larger vectors.The graphs for different values of the sampling time:
8/11/2019 A Study of the Communication Channels and of Noise Sources
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sample time=0.1s sample time=1s sample time=5s
I3.The block scheme for “uniform integer demo”:
Random int MuxMean
& std
Graph
The first device generates integers randomly distributed in the range [0,M-1], where m is
the M-ary number,(M=8). The 2nd
block has at its output the running mean to 1st out-
port and running standard deviation to 2nd
out-port. The mux combines the two inputsignals into larger vectors.
The graphs for different values of the sampling time:
sample time=0.1s sample time=1s sample time=5s
I4.The block scheme for “Poisson random demo”:
Poisson int
Poisson int
generator
Mux
Mean
& var
Graph1
.1Expected value
The first device generates Poisson distributed random integers. The 2
nd block has at its
output the running mean to 1st out-port and running variant to 2
nd out-port. The 3
rd block
has as output a constant 0.1 . The mux combines all the three input signals into larger
vectors.
8/11/2019 A Study of the Communication Channels and of Noise Sources
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The graphs for different values of the sampling time:
sample time=0.1s sample time=1s sample time=5s
I5.The block scheme for “Rayleigh random demo”:
The mean of the Rayleigh noise is s*sqrt(pi/2).
The variance of the Rayleigh noise is s 2*(2-pi/2)
Assume the sigma value is s, then:
RayleighMux
Mean
& var
Graph[sqrt(pi/2), (2-pi /2)]
Expected value
The first device generates Rayleigh distributed noise. The output vector size of this blockis the same as the vector size of the seed (sigma=1). The 2
nd block has at its output the
running mean to 1st
out-port and running variant to 2nd
out-port. The 3rd
block has asoutput a constant [sqrt(pi/2),2-pi/2]. The mux combines all the three input signals intolarger vectors.
The graphs for different values of the sampling time:
sample time=0.1s sample time=1s sample time=5s
I6.The block scheme for “rician random demo”:
8/11/2019 A Study of the Communication Channels and of Noise Sources
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The m ean value o f the sqaure of the Rici an noise output is 2+2K
and the variance of the square of the Rician noise output is 2(2+4K)
Assume the the sigma value i s 1, the means for in-phase and
quadrature are mI and mQ. T he K-factor K=(mI^2+mQ^2)/2, then,
Rician (m)
Rician (K)
Mux
Mean
& var
Mean
& var Graph
[6 20]
Expected value
The first block generates Rician distributed noise. The output vector size of this block is
the same as the vector size of the seed (K=2, sigma=1). The block from bellow is similar
having m=sqrt(2), sigma=1.The following blocks are multipliers or dividers. The other blocks have at its output the running mean to 1
st out-port and running variant to 2
nd out-
port. The block ‘expected value’ has as output a constant [6 20]. The multiplexer
combines all five input signals into larger signals.The graphs for different values of the sampling time:
sample time=0.1s sample time=1s sample time=5s
II.1 The block scheme of the “AWGN noise demo”
Rd wksp - read from workspace- read from a work space variable at sampling time point.
S-QASK – passband S-QASK modulation – modulate the input signal using qadrature
amplitude shift keyng modulation method with square constellation.
8/11/2019 A Study of the Communication Channels and of Noise Sources
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AWGN channel, fixed parameter – additive with Gaussian nise channel with fixed
meanand variance.
S-QASK - passband S-QASK demodulation – demodulate a QASK modulated signal
using sqare constellation.Error meter – symbol/bit error counter – use the input data from the first port as the
reference signal to detect the no. of errors and error rate of the second port input signal.
Sigma=0.1
Stop
time
4 6 8 10 12 14 16 18 20
BER
symbol
0.25 0.15 0.21 0.13 0.14 0.12 0.15 0.133 0.125
BER bit 0.083 0.05 0.07 0.043 0.047 0.042 0.05 0.044 0.041
0
0.05
0.1
0.15
0.2
0.25
0.3
1 2 3 4 5 6 7 8 9
Series2
0
0.02
0.04
0.06
0.08
0.1
1 2 3 4 5 6 7 8 9
Series2
BER symbol=f(t) BER bit=f(t)
Sigma=1
Stop
time
4 6 8 10 12 14 16 18 20
BER
symbol
0.675 0.65 0.612 0.58 0.6 0.557 0.55 0.516 0.575
BER bit 0.275 0.3 0.270 0.26 0.261 0.219 0.22 0.212 0.253
0
0.2
0.4
0.6
0.8
1 2 3 4 5 6 7 8 9
Series2
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
1 2 3 4 5 6 7 8 9
Series2
BER symbol=f(t) BER bit=f(t)
8/11/2019 A Study of the Communication Channels and of Noise Sources
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II.2.The block scheme of the “Raylegh noise demo”:
Rd wksp - read from workspace- read from a work space variable at sampling time point.
S-QASK – passband S-QASK modulation – output the complex envelope of the QASK
modulated signal.This blok uses a sqare constellation with M-ary no. M=2^K,
where K is an integer.Rayl N – Rayleigh noise channel, fixed parameter – additive Rayleigh noise channel for
Baseband signal simulation. Input and output signals are complex.S-QASK – baseband S-QASK demodulation – demodulate the complex envelope of a
QASK modulated signal.This blok uses a fixed sqare constellation with M-ary no.M=2^K, where K is an integer.
Error meter – symbol/bit error counter – use the input data from the first port as the
reference signal to detect the no. of errors and error rate of the second port input signal.
Sigma=0.3
Stop
time
4 6 8 10 12 14 16 18 20
BER
symbol
0.05 0.066 0.025 0.04 0.05 0.057 0.037 0.044 0.03
BER bit 0.016 0.022 0.0083 0.013 0.016 0.019 0.0125 0.014 0.01
8/11/2019 A Study of the Communication Channels and of Noise Sources
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0
0.02
0.04
0.06
0.08
1 2 3 4 5 6 7 8 9
Series2
0
0.005
0.01
0.015
0.02
0.025
1 2 3 4 5 6 7 8 9
Series2
BER symbol=f(t) BER bit=f(t)
Sigma=3
Stop
time
4 6 8 10 12 14 16 18 20
BER
symbol
0.8 0.766 0.775 0.72 0.716 0.7 0.7 0.677 0.78
BER bit 0.433 0.388 0.408 0.366 0.355 0.323 0.333 0.359 0.403
0.6
0.65
0.7
0.75
0.8
0.85
1 2 3 4 5 6 7 8 9
Series2
0
0.1
0.2
0.3
0.4
0.5
1 2 3 4 5 6 7 8 9
Series2
BER symbol=f(t) BER bit=f(t)
II.3 The block scheme of the “Rician noise demo”:
Rd wksp - read from workspace- read from a work space variable at sampling time point.
C-QASK – baseband C-QASK modulation – output the complex envelope of a QASKmodulated signal. The QASK circle constellation is defined by the NIC,RIC
and PIC.
Rician N – Rician noise channel, fixed parameter – additive Rician noise channel for a baseband sinal simulation. Input and output sgnals are complex.
8/11/2019 A Study of the Communication Channels and of Noise Sources
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C-QASK – baseband C-QASK demodulation – demodulate the complex envelope of a
QASK Circle constellation is defined by NIC,RIC and PIC.
Error meter – symbol/bit error counter – use the input data from the first port as the
reference signal to detect the no. of errors and error rate of the second port input signal.
Sigma=0.1
Stop
time
4 6 8 10 12 14 16 18 20
BER
symbol
0.3 0.2 0.1 0.18 0.15 0.128 0.087 0.088 0.12
BER bit 0.071 0.052 0.028 0.054 0.047 0.036 0.032 0.025 0.035
0
0.1
0.2
0.3
0.4
1 2 3 4 5 6 7 8 9
Series2
0
0.02
0.04
0.06
0.08
1 2 3 4 5 6 7 8 9
Series2
BER symbol=f(t) BER bit=f(t)
Sigma=1Stop
time
4 6 8 10 12 14 16 18 20
BER
symbol
0.75 0.666 0.625 0.6 0.633 0.642 0.625 0.622 0.64
BER bit 0.22 0.209 0.16 0.165 0.19 0.187 0.189 0.182 0.174
8/11/2019 A Study of the Communication Channels and of Noise Sources
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0
0.2
0.4
0.6
0.8
1 2 3 4 5 6 7 8 9
Series2
0
0.05
0.1
0.15
0.2
0.25
1 2 3 4 5 6 7 8 9
Series2
BER symbol=f(t) BER bit=f(t)
Laboratory 2
Multiple access techniques
III .1 D-TMA demo
Signal generator – output various wave forms-sine, sawtooth, sine.Mux – combine scalar or vector signals into larger vectors.
D-TDMA mux – digital TDMA input a vecor digital signal. Output a scalar up-sampled
digital signal.D-TDMA demux – reverse digital signal. Output a vector of a down-sampled digital
signal.
Demux – split vector signal into scalars or smaller vectors.
Stop time=10
Input sample time for D-TMAmux and D-TMA dmux=0.01
8/11/2019 A Study of the Communication Channels and of Noise Sources
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Input sample time for D-TMAmux and D-TMA dmux=0.1
Input sample time for D-TMAmux and D-TMA dmux=1
III.2 Time share demo
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Signal generator – output various wave forms-sine, sawtooth, sine.
Mux – combine scalar or vector signals into larger vectors.
Time share mux – analog time division multi access – this block partititions each transfer period into even length time slots.Each element of the input vector takes one slot in turn.
Time share demux – reverse analog TDMA – This block partitions each transfer peiodinto even length time slots.Each element of the output vector takes one time slot to outputthe input in turn.
Demux – split vector signal into scalars or smaller vectors.
Stop time=10
Transfer period at “time share-mux” and “time-share demux”=0.001sec
Transfer period at “time share-mux” and “time-share demux”=0.01sec
Transfer period at “time share-mux” and “time-share demux”=0.1sec
Transfer period at “time share-mux” and “time-share demux”=1sec
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III.3 FDMA demo
Signal generator – output various wave forms-sine, sawtooth, sine.
DSB AM – passband DSB_SC AM – modulate the input signal using DSB-SC AMmethod.
Butter(BP) – butterworth band pass filter.
Sum – add or substract inputs.
AWGN channel, fixed parameter – additive with Gaussian nise channel with fixedmeanand variance.
DSB ADM – passband DSB-SC AM modulated signal.Mux – combine scalar or vector signals into larger vectors.
Stop time=10
Filters’ bandwidth=0.03
Variance of the noise in the channel=0.01
Stop time=10
Filters’ bandwidth=0.03 Variance of the noise in the channel=0.1
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Stop time=10
Filters’ bandwidth=0.03
Variance of the noise in the channel=1
Stop time=10Filters’ bandwidth=0.003
Variance of the noise in the channel=0.01
Stop time=10
Filters’ bandwidth=0.003
Variance of the noise in the channel=0.1
8/11/2019 A Study of the Communication Channels and of Noise Sources
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Stop time=10
Filters’ bandwidth=0.003
Variance of the noise in the channel=1
Stop time=10Filters’ bandwidth=0.3
Variance of the noise in the channel=0.01
Stop time=10
Filters’ bandwidth=0.3
Variance of the noise in the channel=0.1
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Stop time=10
Filters’ bandwidth=0.3
Variance of the noise in the channel=1
III.4 CDMA demo
Signal generator – output various wave forms-sine, sawtooth, sine.
Mux – combine scalar or vector signals into larger vectors.Pulse generator – vector pulses with sample rate of each pulse as Sample_time/Divider.
Vector signal re-distribution – the rising edge from the 2nd
inport triggers the block to
output the input element with the index given in the next row of switch box.
8/11/2019 A Study of the Communication Channels and of Noise Sources
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AWGN channel, fixed parameter – additive with Gaussian nise channel with fixed
meanand variance.
Demux – split vector signal into scalars or smaller vectors.
DSB-AM – passband DSB-SC AM – modulate the input signal using DSB-SC AM
method.
Sum – add or substract inputs.Butter(BP) – butterworth band pass filter.
Butter(BP) – butterworth band pass filter.
DSB ADM – passband DSB-SC ADM – demodulate a DSB-SC AM modulated signal.Mux – combine scalar or vector signals into larger vectors.
Unit delay – sample and hold with one sample period delay.Edge detection – detect the rising edge of the input signal.Output one when the risig edge
is detected.
Sum – add or substract inputs.Zero order hold.
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Stop time=10
Filters’ bandwidth=0.03
Variance of the noise in the channel=0.01
Stop time=10Filters’ bandwidth=0.03 Variance of the noise in the channel=0.1
Stop time=10
Filters’ bandwidth=0.03 Variance of the noise in the channel=1
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Stop time=10
Filters’ bandwidth=0.3
Variance of the noise in the channel=0.01
Stop time=10
Filters’ bandwidth=0.3
Variance of the noise in the channel=0.1
Stop time=10
Filters’ bandwidth=0.3 Variance of the noise in the channel=1