c ase s tudy – p hase 4 t ransmitter r eceiver s imulation siddharth nair g200901750 ee 578
DESCRIPTION
D ATA T RANSMISSION O VER M ULTIPATH C HANNEL 3TRANSCRIPT
CASE STUDY – PHASE 4 TRANSMITTER RECEIVER SIMULATION
Siddharth NairG200901750
EE 578
OUTLINE Multipath Fading Introduction To OFDM OFDM Modulator Receiver Design Convolutional Coding BER Vs SNR Curve Q&A
2
DATA TRANSMISSION OVER MULTIPATH CHANNEL
3
OFDM
4
OFDM SYMBOL – TIME DOMAIN
Courtesy : OFDM For Wireless Multimedia Communications – Richard Van Nee, Ramjee Prasad
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CYCLIC PREFIX
Courtesy : OFDM For Wireless Multimedia Communications – Richard Van Nee, Ramjee Prasad
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OFDM MODULATOR
Courtesy : http://upload.wikimedia.org/wikipedia/
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RECEIVER DESIGN – OFDM RECEIVER
Courtesy : http://upload.wikimedia.org/wikipedia/
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RECEIVER DESIGN – ZF EQUALIZER
Courtesy : http://www.dsplog.com/2008/10/24/mimo-zero-forcing/
9
SIMULATION PARAMETERS OFDM
FFT Size = 128 Cyclic Prefix = 64 Subcarriers 1-10, 119-128 Nulled – Guard Bands Subcarriers 61-69 Nulled To Avoid DC
Components Data Per OFDM Symbol = 100 QPSK Symbols
Baud Rate = 20MHz Frequency Selective Channel
Tap Delays = 0, 2e-6, 2e-7 s Tap Power (dB) = 0, -2, -10
Symbols Per Frame = 4 MIMO Configuration = 2 x 2
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CHANNELS
-0.5 0 0.5 1 1.5 2 2.5
x 10-6
-0.7
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3Resampled, Bandlimited Chanel Impulse Response
RealImag-0.5 0 0.5 1 1.5 2 2.5
x 10-6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1Resampled, Bandlimited Chanel Impulse Response
RealImag
-0.5 0 0.5 1 1.5 2 2.5
x 10-6
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8Resampled, Bandlimited Chanel Impulse Response
RealImag
-0.5 0 0.5 1 1.5 2 2.5
x 10-6
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4Resampled, Bandlimited Chanel Impulse Response
RealImag
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CONSTELLATIONS – NO AWGN ADDED
-1.5 -1 -0.5 0 0.5 1 1.5
-1.5
-1
-0.5
0
0.5
1
1.5
Qua
drat
ure
In-Phase
Before Equalization
-0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
Qua
drat
ure
In-Phase
After Equalization
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BER VS SNR
0 2 4 6 8 10 12 14 16 18 2010
-4
10-3
10-2
10-1
100 BER Vs SNR For 2 x 2 MIMO QPSK ZF Equalizer Transceiver System
SNR
BE
R
13
SIMULATION PARAMETERS OFDM
FFT Size = 128 Cyclic Prefix = 16 Subcarriers 1-10, 119-128 Nulled – Guard Bands Subcarriers 61-69 Nulled To Avoid DC Components Data Per OFDM Symbol = 100 QPSK Symbols
Baud Rate = 1MHz Frequency Selective Channel
Tap Delays = [0 60 75 145 150 150 155 190 220 225 230 335 370 430 510 685 725 735 800 960 1020 1100 1210 1845] * 1e-9
Tap Power (dB) = -6.4,-3.4,-2,-3,-5.2,-7,-1.9,-3.4,-3.4,-5.6,-7.4,-4.6,-7.8,-7.8,-9.3,-12,-8.5,-13.2,-11.2,-20.8,-14.5,-11.7,-17.2,-16.7
Symbols Per Frame = 4 MIMO Configuration = 2 x 2 14
CHANNELS
-4 -2 0 2 4 6
x 10-6
-0.7
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
Tap Delays
Tap
Wei
ghts
Resampled, Bandlimited Channel Impulse Response
RealImag
-4 -2 0 2 4 6
x 10-6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
Tap Delays
Tap
Wei
ghts
Resampled, Bandlimited Channel Impulse Response
RealImag
-4 -2 0 2 4 6
x 10-6
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
Tap Delays
Tap
Wei
ghts
Resampled, Bandlimited Channel Impulse Response
RealImag
-4 -2 0 2 4 6
x 10-6
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
Tap Delays
Tap
Wei
ghts
Resampled, Bandlimited Channel Impulse Response
RealImag
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CONVOLUTIONAL CODING
HALF RATE CONVOLUTIO
NAL ENCODER
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BER VS SNR
0 2 4 6 8 10 12 14 16 18 2010
-5
10-4
10-3
10-2
10-1
100 BER Vs SNR For 2 x 2 MIMO IEEE 802.16m Macrocell Channel Model - QPSK ZF Equalizer Transceiver System
SNR
BE
R
NO CODING1/2 RATE CONVOLUTIONAL CODING
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THANK YOU !!
QUESTIONS AND COMMENTS