1. Malong Wang Ting-change
Performance Analysis and Simulations of UWB PAM Communications In AWGN Channel
Malong Wang Ting-change
8/7/2019
Inha Telecom. Lab.

2. Name of Journal or Conference
2004 4th International Conference on Microwave and Millimeter Wave Technology Proceedings
@2004 IEEE
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Inha Telecom. Lab.

3. Objectives
Deduces the theory of BER for PAM end-to-end communications in AWGN channel
Analyzes the BER curves and draws out the conclusions about optimum non-bipolar PAM signal and about the superiority of bipolar PAM signal
It validates the theoretical prediction through simulations
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Inha Telecom. Lab.

4. Contents Introduction BER Formula for non-bipolar PAM Signal
BER Formula for bipolar PAM signal
Analysis of BER Figures
Simulation Results
Conclusion
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Inha Telecom. Lab.

5. Introduction There are two basic methods to produce UWB signals:
to make use of OFDM in producing a GHz signal
(2) directly produce a pulse, and this pulse’s duration is only in the level of nanosecond (IR Radio Technology)
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Inha Telecom. Lab.

6. Introduction
The UWB technology based on nanosecond impulse has been widely concerned in military applications
because of its LPDD (low probability of detection/interception), very high data rate and low power consumption
There are two primary ways to realize the modulation of information: PAM (pulse amplitude modulation) and PPM (Pulse position modulation)
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Inha Telecom. Lab.

7. Introduction
Since the capability and quality of end-to-end communications between radios are major considerations in military communications
This paper focuses on end-to-end communications adopting binary UWB-PAM signals
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Inha Telecom. Lab.

8. BER Formula for non-bipolar PAM Signal
The pulse shapes of s0(t) and sl(t) are the same, and the energy of %(t) is l/k of sl(t)'s
In AWGN channel, a matched filter maximizes the output signal-to-noise ratio (SNR) and probability density of signals outputted by matched filter are
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Inha Telecom. Lab.

9. BER Formula for non-bipolar PAM Signal
When pp(r|s1,)> (1-p) p(r|s0), we decide S1 as the transmitted signal;
when pp(r|s1,)< ( 1 -p) p(r|So), we decide s0 as the transmitted
Assuming the decision threshold is b then pp(b|s1)=(1-p)p(b|s0) ……….(4)
8/7/2019
Inha Telecom. Lab.

10. BER Formula for non-bipolar PAM Signal
Normalizing the sl(t), i.e. to make Eb=1.
And assume “0”,”1” of the original data are equally probable a priori, i.e. p=0.5. We can express (5) as (6)
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Inha Telecom. Lab.

11. BER Formula for non-bipolar PAM Signal
Given that sl(t) was transmitted, the probability of
error is:
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Inha Telecom. Lab.

12. BER Formula for non-bipolar PAM Signal
Similarly, given that s0(t) was transmitted the
probability of error is
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Inha Telecom. Lab.

13. BER Formula for bipolar PAM Signal
Assuming transmitter will produce a impulse signal s1(t) if there is a digital “1”, and will produce a impulse signal s0(t) if there is a digital “0”
The probability of sl(t) is p, and the probability of s0(t) is 1-p,
the pulse shapes of s0(t) and sl(t) are the same, and s0(t)=-sl(t).
Then, (1) (3) (5) (6) (7) transform into (1O) (11) (12) (13) (14) respectively
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14. BER Formula for bipolar PAM Signal
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15. Analysis of BER Figures
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16. Analysis of BER Figures
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17. Simulation Results
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18. Simulation Results
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19. Conclusion Non-bipolar PAM will be optimum if SNR is around 10 dB
In general the bipolar PAM signal is superior to the non-bipolar PAM signal
The tendency of UWB-PAM BER is predicted and the validity of this prediction is validated through simulations
8/7/2019
Inha Telecom. Lab.

20. THE END
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Inha Telecom. Lab.

21. Pulse Amplitude Modulation (PAM)
Amplitude of periodic pulse train is varied according to the message signal m(t)
Digital PAM: coded pulses of the sampled and quantized message signal are transmitted (next slide)
Analog PAM: message signal is sampled every Ts seconds (symbol period) and held for T seconds t Ts T
T+Ts
2Ts
p(t) t
m(t) Ts T
T+Ts
2Ts
s(t)
m(0)
m(Ts)
Pulse shape is rectangular pulse
See lecture 12
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22. Pulse Amplitude Modulation (PAM)
Transmission on communication channels is analog
One way to transmit digital information is called 2-level digital PAM
receive ‘0’ bit Tb -A
‘0’ bit t Tb -A
Additive Noise Channel
input
output
x(t)
y(t)
receive‘1’ bit Tb t A
‘1’ bit Tb t A
How does the receiver decide which bit was sent?
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23. 8/7/2019
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24. Explanation
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