User Manual

RF control interface
99-137719-D Confidential - For internal use 9-15
9999
RF & RF control interface
on page 8-51), and enter a dedicated error state where all modem functionality will
be deactivated.
The transmission supervisory functionality is per default activated. It can be
deactivated by the parameter .rfctrl.tx.ctrl.tx_ack_en (see section 6.5.5 on page 6-24).
The B2B_Tx_Ack signal is active high (i.e. high = transmitting, low = not transmitting).
9.2.5 Definition of timing points t
0
and t
1
The timing point, t
0
, is defined as a point on the ramp-up period of a burst. It
represents a fixed point (in time) on the power envelope of the bursts which is at a
certain power level. This point corresponds to the start of the first CW symbol (half a
symbol prior to optimum symbol timing) as illustrated in the following figure.
Figure 9-14: Timing of the Tx acknowledgement signal (B2B_Tx_Ack)
Note
Notice that the transmission supervisory functionality also is active in no-
transmission periods whereas the Tx acknowledgement signal must have the
same polarity as the Tx control signal. If this is not the case an abnormal
behaviour message (MSG_ABNORMALITY) will be generated and the error
state will be entered.
B2B_Tx_Ack
Tx out
L-band signal
t
1
t
0
t
1
+t
guard
data Burst
t
0
+t
guard
t
0
-t
guard
t
1
-t
guard
TransmissionNo-transmission No-transmission