Mobile Communications
Chung-Ang University
Mobile Communication Lab
Cho, Yong Soo
Mobile CommunicationSimulation
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
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Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
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Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
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Simulink 6
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulink 6
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Simulation
Simulation start <Ctrl+T> Simulation run
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 1 (1)
Simulation Assignment (Block Level)
Raised-cosine pulse spectrum
Plot time / frequency response
Change the value of roll-off factor (0, 0.5, 1)
Eye diagram
Understand how to generate eye diagram
Plot eye diagram
Transversal filter
Plot output signal of transmit filter / eye diagram
Plot output signal of channel / eye diagram
Plot output signal of 3-tap zero forcing equalizer / eye diagram
Plot output signal of 5-tap zero forcing equalizer / eye diagram
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 1 (2)
Raised cosine transmit filter
Filter type : Square root / Normal
Group delay : 4 symbols
Roll-off factor : 0~1
Up sampling : 8
Rolloff factor : 1
Rolloff factor : 0.25
Impulse
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 1 (3)
Eye diagram
Random (1,0) (+1,-1)
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University8
Simulation Assignment 1(4)
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University9
Simulation Assignment 1(5)
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University10
Simulation Assignment 1(6)
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 1 (7)
Transversal filter
Time
Vector
Scope4
Time
Vector
Scope3Time
Vector
Scope2
Time
Vector
Scope1
Unipolar to
Bipolar
Converter
Unipolar to
Bipolar
Converter
In1 Out1
Subsystem
Random
Integer
Random Integer
Generator
Normal
Raised Cosine
Transmit Filter3
Normal
Raised Cosine
Filter
Normal
Raised Cosine
Filter2
Normal
Raised Cosine
Filter1
Discrete-Time
Eye Diagram
Scope3
Discrete-Time
Eye Diagram
Scope2
Discrete-Time
Eye Diagram
Scope1
Discrete-Time
Eye Diagram
Scope
In1 Out1
5Tap EQ
In1 Out1
3Tap EQ
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 1 (8)
Transmit data
4-ary PAM (bipolar)
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 1 (9)
Impulse response of transmit filter & channel
Cn=[0.0, 0.2, 0.9, -0.3, 0.1]
Normalization gain
• Sum ( |Cn| )
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 1 (10)
3-tap zero forcing equalizer
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 1 (11)
5-tap zero forcing equalizer
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 1 (12)
Simulation Assignment (Communication System Level)
Signal generator: Select sine wave(10V , 1kHz)
Plot the waveform of time scope at each stage
Plot impulse / frequency response of normal raised cosine filter (Rolloff factor: 1, 0.25)
– Plot the output of filter (input: impulse) using vector / spectrum scope
Plot the reconstructed sine wave after analog filter
– 10kHz sampling, 64 level quantization
– Modulation = 16QAM
– Buffer size = 4
– Square root raised cosine filter ( group delay = 4)
– Analog filter order = 3, 18
Signal generator: Select Random(10V, 1kHz)
Plot analytic BER curve (0~10dB) using equation
– BPSK, QPSK, 16QAM, 64QAM
Plot simulation result by changing Eb/No (step size: 1dB) for different modulation order
– BER (compare with analytic BER curve, Use square root raised cosine filter)
– EYE diagram (Use normal / square root raised cosine filter)
– Constellation (Use square root raised cosine filter at both transmit and receive sides)
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 1 (13)
Basic Communication Blocks
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 1 (14)
Sampling
Message signal
Sine wave : amplitude=10, 1kHz
Random : amplitude=10, 1kHz
Pulse Generator
Frequency : 10kHz, oversampling (5 times)
Pulse width : 0.025%
– Similar to discrete impulse
Sine wave
Impulse
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 1 (15)
Quantization
Quantizer blockset
Quantization interval: 10/32 → -10 ~ +10 (64 level)
Continuous level → discrete level
PCM generation
Uniform encoder (output: integer type)
Need an integer to bit converter
Output of PCM generator: 6bits
Buffer
Output of Buffer: 4bits (16QAM)
Modulation
Select Blockset corresponding to modulation order
Constellation ordering : Gray code
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 1 (16)
AWGN channel Mode : EbNo
Number of bits per symbol and symbol period need to be selected
according to modulation order Number of bits per symbol : 4bits
Symbol period : 1/6e4*4/8
Raised cosine receive filter Filter type : square root
Input sample per symbol : 8
Group delay : 4 symbols
Roll-off factor : 0.25
Down sampling : 8
Demodulation Select Blockset corresponding to modulation order
Constellation ordering : Gray code
Buffer1 Input: 4bits, Output: 6bits
Error rate calculation System delay : Group delay * bits per symbol * 2
16QAM : 4*4*2
Output data : port
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 1 (17)
Uniform decoder
Analog Filter
Method : Butterworth
Type : Lowpass
Filter order : 3, 18
Passband edge freq. : 2kHz
Order : 18Order : 3
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 1 (18)
Parameter setting depending on modulation order
Buffer size and Group delay need to be changed because of internal characteristic of Raised cosine filter block
Modulation Buffer size Group delay(Raised cosine filter)
B P S K 4 4
Q P S K 4 2
16 QAM
4 4
8 2
64 QAM
6 4
6 2
12 4
12 2
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 1 (19)
Constellation / Eye diagram (Eb/No : 4dB)
Eye diagram: both Normal / Square root raised cosine filter
BPSK
QPSK
Normal raised cosine Square root raised cosine
Normal raised cosine Square root raised cosine
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 1 (20)
16QAM
64QAMNormal raised cosine Square root raised cosine
Normal raised cosine Square root raised cosine
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 1 (21)
BER curve
Use Matlab internal function erfc()
Run simulation time : more than 105
0 1 2 3 4 5 6 7 8 9 1010
-3
10-2
10-1
100
BER Curve for AWGN Channel (Analytic / Simulation)
EbN0[dB]
BE
R
Analytic-16QAM
Analytic-64QAM
Simulation-16QAM
Simulation-64QAM
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 2 (1)
Direct-Sequence Spread Spectrum and Multi-path Fading Channel
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 2 (2)
Simulation Assignment
DS-SS
Generate the PN sequence in textbook and plot autocorrelation property
Plot time-domain and frequency-domain characteristics of the spread signal
Plot BER curve when narrow-band interference signal is present
1-tap Rayleigh fading channel
Plot the magnitude of signal before and after Rayleigh fading channel
Plot impulse response
Plot frequency response
Plot Doppler spectrum
Compare with analytic BER curve
Plot distributions of amplitude, real, and image signal
3-tap Rayleigh fading channel
Plot impulse response
Plot frequency response
Plot Doppler spectrum
Plot BER curve
Plot BER curve when Rake receiver is used
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 2 (3)
DS-SS (PG = 15)
Message signal : Binary random (sampling time : 1e-3/2)
Modulation : QPSK
PN sequence : PN sequence generator
sampling time : 1e-3/15
Generator polynomial : [1 1 0 0 1]
Normalizing gain : 1/sqrt(15)
Autocorrelation property of PN sequence using M-file
0 5 10 15 20 25 30-0.2
0
0.2
0.4
0.6
0.8
1
1.2
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 2 (4)
Spreading effect
Time domain
Message
Real
Message
Imag
Code
Spread
Real
Spread
Imag
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 2 (5)
15 ⅹspreading
Spreading effect
Frequency domain
Pulse shaping using raised cosine filter
Increase frequency dimension
using Up sampling in Raised cosine filter
Raised cosine filter parameter (unspread)
– Roll-off factor : 0
– Up sampling : 30
Raised cosine filter parameter (spread)
– Roll-off factor : 0
– Up sampling of spread : 2
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 2 (6)
DS-SS BER Curve with Jamming signal
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 2 (7)
DS-SS BER Curve with Jamming signal
Jamming signal
Sine wave : 0.5V, 250Hz
Frequency spectrum
0 1 2 3 4 5 6 7 8 9 1010
-6
10-5
10-4
10-3
10-2
10-1
100
BER Curve for AWGN Channel (Analytic / Simulation)
EbN0[dB]
BE
R
Analytic-QPSK
Spread-QPSK
Unspread-QPSK
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 2 (8)
1-Tap Rayleigh channel
Maximum Doppler shift : 10Hz
Correspond to the speed of 10.8km/hr when carrier frequency is 1GHz
0 5 10 15 20 25 3010
-7
10-6
10-5
10-4
10-3
10-2
10-1
100
Eb/N0 (dB)
BE
R
BER Curve for Rayleigh Channel(Analytic / Simulation)
Analytic-AWGN QPSK
Analytic-Rayleigh QPSK
Simulation
Magnitude
After Rayleigh channel
Magnitude
Before Rayleigh channel
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 2 (9)
Distribution for Rayleigh Fading Channel
Use Histogram after saving to Workspace
Compare with Analytic Gaussian / Rayleigh distribution
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50
500
1000
1500
2000
2500
3000
3500
4000
4500Distribution for Magnitude
-5 -4 -3 -2 -1 0 1 2 3 4 50
1000
2000
3000
4000
5000
6000Distribution for Imag Signal
-5 -4 -3 -2 -1 0 1 2 3 4 50
1000
2000
3000
4000
5000
6000Distribution for Real Signal
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 2 (10)
Multi-path Rayleigh Fading Channel
Maximum Doppler shift : 10Hz
Delay vector : [0 1e-3/15 2e-3/15]
Gain vector in dB : [0 -3 -6]
0 5 10 15 20 25 3010
-7
10-6
10-5
10-4
10-3
10-2
10-1
100
Eb/N0 (dB)
BE
R
BER Curve for Rayleigh Channel(QPSK)
Analytic-AWGN QPSK
Analytic-Rayleigh QPSK
Multi-path Simulation
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 2 (11)
AWGN
Number of bits per symbol : 30bits (QPSK)
Symbol period : 1e-3
Channel Estimation
Estimate magnitude and phase of each tap using impulse response
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 2 (12)
Rake Receiver
Use 3 fingers
Despread the signal for each tap
Use MRC Combining
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 2 (13)
MRC Combining
Mobile Communication Lab
Cho, Yong Soo
Mobile Communications
Chung-Ang University
Simulation Assignment 2 (14)
Multi-path Rayleigh Fading Channel with Rake Receiver
0 2 4 6 8 10 12 14 16 18 2010
-7
10-6
10-5
10-4
10-3
10-2
10-1
100
Eb/N0 (dB)
BE
R
BER Curve for Rayleigh Channel(QPSK)
Analytic-AWGN QPSK
Analytic-Rayleigh QPSK
Multi-path, No Rake Receiver
Multi-path, Rake Receiver