FX929A Datasheet, PDF (42/44 Pages) CML Microcircuits – 4-Level FSK Modem Data Pump

4-Level FSK Modem Data Pump
FX929A
1E-1
1E-2
1E-3
1E-4
With FEC
Without FEC
1E-5
4
5
6
7
8
9
10
11
12
13
14
S/N dB (Noise in 2 x Symbol Rate Bandwidth)
Figure 22 Typical Bit Error Rate With and Without FEC
Measured under nominal working conditions, LEVRES bits set to 'Slow Peak Detect' and PLLBW bits set to
'Narrow Bandwidth' , with pseudo-random data.
Note: S/N calculated as 20 × LOG10( Signal Voltage ÷ Noise Voltage)
Where Signal Voltage is the measured rms. voltage of a random 4-level signal.
Noise Voltage is the rms. voltage 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 system).
Both signals are measured at the same point in the test circuit.
© 1996 Consumer Microcircuits Limited
42
D/929A/4