M3SR Series 4100 Changing the Rx and Tx Data Rate
4.128 Operating Manual 6175.4760.02 – 01
4.5.3.1 Changing the Rx and Tx Data Rate
Softkey Selection / Editor Description
Listbox 1. Press ‘RX Data' or 'Tx Data' softkey.
2. Select desired data rate from listbox.
3. Press 'ENT' to confirm.
The data rate and coding should be chosen
according to actual HF channel conditions. For
degraded channels with the presence of high
noise and multipath fading it is advisable to se-
lect low data rates and longer interleaver
lengths. Such constellations will result in high
bit error rates or even totally failed communi-
cation.
For very poor channels and for most reliable
data transmission, try to operate with the most
robust 75 bps data rate and longer interleaver.
Data rates above 6400 bps are mainly used in
ground wave communication. The use of data
rates without forward error correction (FEC) is
not advisable.
Further, uncoded data rates may not be com-
patible with other modems due to a lack of pre-
cision in the standard.
The data rate shown here reflects the total
throughput of payload data which can be
achieved with the over the air data transmis-
sion.
For waveforms with autobaud capability like
STANAG 4539 and MIL-STD-188-110B App.
F the HF Modem is able to detect the appropri-
ate Rx data rate automatically with the pres-
ence of a reception signal. Therefore an
adjustment of Rx data rate is not possible for
autobaud waveforms.
For waveforms without autobaud capability
like STANAG 4285, STANAG 4529 and
STANAG 4481 FSK the data rate and coding
chosen for the transmitter need to match the
adjusted data rate at the receiver on the other
end of the link.
For the waveform S4481 PSK and for S5065
FSK/MSK, there is just one fixed data rate
defined, it is not possible to change this
setting.
For available data rates, please check the ta-
bles below.
To Next Page
Loading...