Programming Information
25
Therefore, perform the following calculations and determine if the results fall
within the stated range:
1.
Calculate the demodulator data rate to carrier frequency ratio.
2.
Calculate the modulator data rate to carrier frequency ratio.
3.3.4
Calculation of the Symbol Rate
The symbol rate is dependent upon the PCM format selected. Calculate the sym-
bol rate as shown below:
1.
Symbol Rate = Demod DR x PCM Factor
3.3.5
Evaluation of the Demodulator E
b
/N
o
Setup
The E
b
/N
o
setup parameter directly effects the loop bandwidth selection which
in turn effects the ability of the demodulator to obtain lock and remain locked.
To determine the loop bandwidth (LBW) first refer to
Table 3.3.1
. Select the
LPSR based on the E
b
/N
o
selected in
Section 3.3.1
. Multiply this value by the
Symbol Rate determined in
Section 3.3.4
.
1.
Loop Bandwidth (LBW) = LPSR x Symbol Rate
(Ratio: <0.25)
Demod Ratio
=
(Ratio: <0.25)
Mod Ratio
=
If variable Demod PCM = BI
Φ
then PCM Factor = 2
If variable Demod PCM = NRZ then PCM Factor = 1
Symbol Rate
=
(Range 4430-V: 9Hz to 130kHz)
(Range 4430-VN: 0.25Hz to 3kHz)
LBW
=
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