DB929B datasheet(48/51 Pages) CMLMICRO

48 / 51 page

4-Level FSK Modem Data Pump

Page 48 of 50

MX929B PRELIMINARY INFORMATION

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Fax: 336 744 5054

Doc. # 20480171.003

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6.1.5

Typical Bit Error Rate

1E-6

1E-5

1E-4

1E-3

1E-2

1E-1

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:

¸¸¹

¨¨©

Voltage

Noise

Voltage

Signal

20log10

calculates

Where:

Signal Voltage is the measured VRMS of a random 4-level signal.

Noise Voltage is the VRMS 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.

DB929B Datasheet(PDF) 48 Page - CML Microcircuits