General Information
ARQ-E is a synchronous dual channel ARQ mode for the exchange of teletype-data over a radio channel in a robust way.
Usage:
§ Military or diplomatic data communication over HF.
Mode Details
|
|
Item |
Value | |
|
Standard |
Modulation |
FSK | |
|
|
Number of tones |
2 | |
|
|
Shift (Hz) |
170 |
370 |
|
|
Bandwidth (Hz) |
300 |
600 |
|
|
Symbol rate (Bd) |
30 … 650 | |
|
|
Error correction |
ARQ | |
|
|
Alphabet |
ITA-2 extended | |
|
Demodulator Settings |
Demodulator |
FSK 2 matched | |
|
|
Symbol rate (Bd) |
85.7 |
185 |
|
|
SR tolerance (Bd) |
4 |
5 |
|
|
Shift (Hz) |
170 |
370 |
|
|
Shift tolerance (Hz) |
20 | |
|
|
Modem type |
Synchronous | |
|
Features |
Demodulation |
yes | |
|
|
Recognition |
yes | |
|
|
Decoding |
yes | |
|
|
Automatic Polarity Adjustment |
yes | |
|
|
Combination with other modems (modem list) |
yes | |
|
Tuning |
The tuning frequency is the center of the signal | ||
Table 16: ARQ-E
Figure 6: ARQ-E cyc4 Spectrogram
Figure 7: ARQ-E cyc8 Spectrogram