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1.5 Technical
Terms
1-21
1
Outline
Bit Error Rate
The Bite Error Rate is the ratio of the total received bits and error bits.
It depends on the SNR (signal to noise ratio).
Signal Amplitude s
Standard Deviation of
Noise Amplitude n
Bit error ratio
Threshold
Figure 1.5-11 Bit Error Rate
When the distribution of the noise voltage amplitude is assumed to follow
a normal distribution, the standard deviation is assumed to be n and the
signal amplitude is s. Bit errors occur when the noise amplitude is larger
than the signal amplitude. Consequently, the probability of amplitude
occurring is the bit error ratio.
The bit error ratio, BER, is calculated by the following formula.
dx
x
BER
n
s
)
2
exp(
2
1
/
2
When the SNR is large (greater than 4), the relationship between SNR
and BER becomes linear when plotted on a semi-logarithmic graph.
SNR(dB)
2
3
4
5
6
7
8
9
10
-2
10
-3
10
-5
10
-10
10
-7
10
-12
BER
Figure 1.5-12 Relationship between SNR and BER
Summary of Contents for BERTWave MP2100B
Page 24: ...xxiv...
Page 96: ...Chapter 2 Before Use 2 42...
Page 112: ...Chapter 3 Connecting with DUT 3 16...
Page 250: ...Chapter 7 Measuring Waveform 7 64 Figure 7 12 1 Marker Display...
Page 262: ...Chapter 7 Measuring Waveform 7 76...
Page 276: ...Chapter 8 Operating Optical Interface 8 14...
Page 304: ...Chapter 9 Performance Test 9 28...
Page 320: ...Chapter 10 Maintenance 10 16...
Page 374: ...Appendix E Performance Test Record Form E 10...
Page 382: ...Index Index 6...