Post on 05-Feb-2016
description
Khurram MasoodKhurram Masood200806100200806100
PSK-Based Digital Transmission PSK-Based Digital Transmission SystemsSystems
Chapter 3 of Hiroshi Harada Book Chapter 3 of Hiroshi Harada Book
• BPSK transmission scheme– Some instantaneous waveforms– BER performance
• Other PSK transmission schemes– QPSK– OQPSK– MSK– GMSK
• QAM for transmission– 16-QAM
OutlinesOutlines
BPSK Transmission SchemeBPSK Transmission Scheme
04/22/23 3
Simulated instantaneous waveformsSimulated instantaneous waveforms
04/22/23 4
0 5 10-1
-0.5
0
0.5
1BPSK tx data
Am
plitu
de
0 50 100-1
-0.5
0
0.5
1BPSK tx oversampled data
0 50 100-2
-1
0
1
2BPSK tx signal
0 20 40 60 80-2
-1
0
1
2BPSK rx signal
Am
plitu
de
Samples-1 0 1
-1
-0.5
0
0.5
1BPSK phaser
I-Phase
Q-P
hase
Theoretical and simulated Theoretical and simulated BER performanceBER performance
04/22/23 5
0 5 10 15 20 25 30 35 4010
-4
10-3
10-2
10-1
100
Eb/N
0 [dB]
BE
RBPSK performance
BPSK AWGN theory
BPSK AWGNBPSK Rayleigh theory
BPSK Rayleigh
QPSK transmissionQPSK transmission
• BPSK is simple in configuration• QPSK signal is generated by 2 BPSK signals• QPSK has higher frequency utilization efficiency
04/22/23 6
Simulated instantaneous QPSK waveformsSimulated instantaneous QPSK waveforms
04/22/23 7
0 10 200
0.5
1QPSK tx data
Am
plitu
de
0 50 100-1
-0.5
0
0.5
1QPSK tx oversampled
0 50 100-1
-0.5
0
0.5
1QPSK tx oversampled data[Q]
0 50 100-2
-1
0
1
2QPSK rx signal[I]
Am
plitu
de
0 50 100-2
-1
0
1
2QPSK rx signal[Q]
-1 0 1
-1
0
1
QPSK phaser
I-data
Theoretical and simulated QPSK Theoretical and simulated QPSK BER performanceBER performance
04/22/23 8
0 5 10 15 20 25 30 35 4010
-4
10-3
10-2
10-1
100
Eb/N
0 [dB]
BE
RQPSK performance
QPSK AWGN theory
QPSK AWGNQPSK Rayleigh theory
QPSK Rayleigh
OQPSK transmissionOQPSK transmission
• QPSK transmission may result in a phase change of 180⁰ between two symbols, causing the spectrum to spread
• OQPSK avoid origin crossings in the phase• Q-channel is half a symbol delayed from that of
I-channel signal
04/22/23 9
Simulated instantaneous OQPSK waveformsSimulated instantaneous OQPSK waveforms
04/22/23 10
0 10 200
0.5
1OQPSK tx data
Am
plitu
de
0 50 100-1
-0.5
0
0.5
1OQPSK tx oversampled
0 50 100-1
-0.5
0
0.5
1OQPSK tx oversampled
0 50 100-2
-1
0
1
2OQPSK rx signal[I]
Am
plitu
de
0 50 100-2
-1
0
1
2OQPSK rx signal[Q]
-1 0 1
-1
0
1
OQPSK phaser
I-data Q-data
Theoretical and simulated OQPSK Theoretical and simulated OQPSK BER performanceBER performance
04/22/23 11
0 5 10 15 20 25 30 35 4010
-4
10-3
10-2
10-1
100
Eb/N
0 [dB]
BE
ROQPSK performance
OQPSK AWGN theory
OQPSK AWGNOQPSK Rayleigh theory
OQPSK Rayleigh
MSK transmissionMSK transmission
• Although OQPSK is good in reducing the big phase changes, the amplitude fluctuates
• MSK is used to stabilize the amplitude
04/22/23 12
Simulated instantaneous MSK waveformsSimulated instantaneous MSK waveforms
04/22/23 13
0 10 200
0.5
1MSK tx data
Am
plitu
de
0 50 100-1
-0.5
0
0.5
1MSK tx oversampled
0 50 100-1
-0.5
0
0.5
1MSK tx oversampled data[Q]
0 50 100-2
-1
0
1
2MSK rx signal[I]
Am
plitu
de
0 50 100-2
-1
0
1
2MSK rx signal[Q]
-1 0 1
-1
0
1
MSK phaser
I-data
Theoretical and simulated MSK Theoretical and simulated MSK BER performanceBER performance
04/22/23 14
0 5 10 15 20 25 30 35 4010
-4
10-3
10-2
10-1
100
Eb/N
0 [dB]
BE
RMSK performance
MSK AWGN theory
MSK AWGNMSK Rayleigh theory
MSK Rayleigh
GMSK transmissionGMSK transmission
• In MSK maximum phase transition is limited to pi/2 in phase transition
• Fluctuation is not smooth• Used for GSM mobile phone system• Expanded version of MSK• Amplitude is constant like in MSK• Phase transition is smooth as well
04/22/23 15
Simulated instantaneous GMSK waveformsSimulated instantaneous GMSK waveforms
04/22/23 16
0 50 100-1
-0.5
0
0.5
1GMSK tx data
Am
plitu
de
0 50 100-1
-0.5
0
0.5
1
GMSK tx data afterGaussian filtering
0 50 100-12
-10
-8
-6
-4GMSK phase variation
0 50 100-1
-0.5
0
0.5
1GMSK tx signal
Am
plitu
de
-10 0 10-10
-5
0
5
10GMSK phaser
Theoretical and simulated GMSK Theoretical and simulated GMSK BER performanceBER performance
04/22/23 17
0 5 10 15 20 25 30 35 4010
-4
10-3
10-2
10-1
100
Eb/N
0 [dB]
BE
RGMSK performance
GMSK AWGN theory
GMSK AWGNGMSK Rayleigh theory
GMSK Rayleigh
QAM transmissionQAM transmission
• Increased transmission rate with high frequency utilization efficiency
04/22/23 18
Simulated instantaneous 16QAM waveformsSimulated instantaneous 16QAM waveforms
04/22/23 19
0 10 200
0.5
116QAM tx data
Am
plitu
de
0 50 100-1
-0.5
0
0.5
116QAM tx oversampled
0 50 100-1
-0.5
0
0.5
116QAM tx oversampled
0 50 100-1
0
1
216QAM rx signal[I]
Am
plitu
de
0 50 100-2
-1
0
1
216QAM rx signal[Q]
-1 0 1
-1
0
1
16QAM phaser
I-data Q-data
Theoretical and simulated 16QAM Theoretical and simulated 16QAM BER performanceBER performance
04/22/23 20
0 5 10 15 20 25 30 35 4010
-4
10-3
10-2
10-1
100
Eb/N
0 [dB]
BE
R16QAM performance
16QAM AWGN theory
16QAM AWGN16QAM Rayleigh theory
16QAM Rayleigh