Data Sheet
4-Level FSK Modem Data Pump Page 45 of 47 MX919B PRELIMINARY INFORMATION
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6.1.5 Typical Bit Error Rate
1E-6
1E-5
1E-4
1E-3
1E-2
1E-1
8 9 10 11 12 13 14 15 16
S/N dB (Noise in 2 x Symbol RateBandwidth)
BER
BER with FEC
BER without FEC
Figure 29: Typical Bit Error Rate With and Without FEC
Measured under nominal working conditions, LEVRES bits set to 'Level Track' or 'Slow Peak Detect' and
PLLBW bits set to 'Medium' or 'Narrow' Bandwidth, Command Register TXIMP bit set to '0' or '1' (same for Tx
and Rx devices), with pseudo-random data.
Note:
)
Noise Voltage
Voltage Signal
(20log as calculates N/S
10
Where: Signal Voltage is the measured V
RMS
of a random 4-level signal.
Noise Voltage is the V
RMS
of a flat Gaussian noise signal having a bandwidth from a few Hz to
twice the symbol rate e.g. to 9600Hz when measuring a 4800 symbol/sec (9600bps) system.
Both signals are measured at the same point in the test circuit.