Wavecom W40PC, Руководство пользователя

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Transmission Modes WAVECOM Decoders v6.15 W40PC, W41PC, W51PC
Baudrate 96, 87, 200 Baud, variable 30-650 Baud
Modulation SSB or DIRECT-FSK
Receiver settings CW, LSB or USB
Signal source(s) AF, HF or IF
Alphabet ITA-3
ARQ-M2-342 and ARQ-M2-242 systems operate at speeds of 85.7, 96 or 200 Baud on the
radio link.
These operating modes, also known as TDM or ARQ-28, conform to CCIR recommendations
342-2 and 242. Two 50 Baud Baudot channels are interleaved to form a time multiplexed
aggregate bitstream. Multiplex frames of 28 and 56 bits are used.
The ITA-3 7 bit alphabet is used allowing error detection. The ITA-3 alphabet is a balanced
code in which each character has a mark-space bit ratio of 3:4. ARQ-M2-342 and ARQ-M2-
242 systems are full duplex systems.
Full duplex systems send a repeat request (RQ) character to the remote station if a character
error has been detected or the distortion or fading becomes excessive. This results in the re-
transmission of the last 3 or 7 characters preceded by the RQ request control character.
According to the CCITT recommendation, the repetition cycle may span 4 or 8 characters, as is
the case with ARQ-E. The longer RQ-cycle of 8 characters has never been monitored.
In addition to the time multiplexing of several channels (division channels), each division
channel may be further subdivided into sub-channels resulting in a multitude of possible modes
of operation. At present however no transmissions with sub-channel division are known.
Systems employing sub-channel division may be recognized by a rhythmic blinking of the
Error indication (system state) in the decoder status bar.
ARQ-M4-342 and ARQ-M4-242
Parameter Value
Frequency range HF
System DUPLEX, TDM REC242/REC342-2
Baudrate 96-200 Baud, variable 30-650 Baud
Modulation SSB or DIRECT-FSK
Receiver settings CW, LSB or USB
Signal source(s) AF, HF or IF
Alphabet ITA-3
ARQ-M4-342 and ARQ-M4-242 systems operate at a speed of 172 or 192 Baud on the radio
link.
These operating modes, also known as TDM or ARQ-56, conform to the CCIR
recommendations 342-2 and 242. Four 50 Baud Baudot channels are interleaved to form a time
multiplexed aggregate bitters. Multiplex frames of 56 bits are used.
The ITA-3 7 bit alphabet is used allowing error detection. The ITA-3 alphabet is a balanced
code in which each character has a 3 to 4 ratio between mark and space bits (balanced code).
ARQ-M4-342 and ARQ-M4-242 are full duplex systems.
Full duplex systems send a repeat request (RQ) character to the remote station if a character
error has been detected or the distortion or fading becomes excessive. This results in the re-
transmission of the last 3 or 7 characters preceded by the RQ request control character.
According to the CCITT recommendation, the repetition cycle may span 4 or 8 characters, as is
the case with ARQ-E. The longer RQ-cycle of 8 characters has never been monitored.