4-Level FSK Modem Data Pump
6.1.5 Typical Bit Error Rate
1E-1
Page 48 of 50
MX929B PRELIMINARY INFORMATION
BER with FEC
1E-2
BER without FEC
1E-3
BER
1E-4
1E-5
1E-6
8
9
10
11
12
13
14
15
16
S/N dB (Noise in 2 x Symbol RateBandwidth)
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:
§
·
Signal Voltage
Noise Voltage
¨
¨
¸
¸
S/N calculates as 20log10
©
¹
Where:
Signal Voltage is the measured V
of a random 4-level signal.
RMS
Noise Voltage is the V
of a flat Gaussian noise signal having a bandwidth from a few Hz to
RMS
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.
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