Mocomtech CDM-QX Config„Tx„Txα TX Roll-Off α factor, Config„Rx Receive, Tx Roll-off 20% 35% ENT

CDM-Qx Satellite Modem	Revision 5
Front Panel Operation	MN/CDMQx.IOM

(Config„Tx„Txα) – TX Roll-Off (α) factor

Tx Roll-off: 20% 35%

(◄ ►, ENT)

Select 20% or 35%, using the ◄ ► arrow keys, then press ENT. The default is 35%.

5.6.1.3(Config„Rx) - RECEIVE

The sub-branches available are:

Rx:FEC Demod Code Data Freq

Acq Descram Buf Inv Misc CnC

Select FEC, Dem, Code, Data, Frq, Acq, Descram, Buf, Inv, Misc, or CnC→ using the WXarrow keys, then press ENT. The user will then be taken to a further sub-menu. Each of these choices is described briefly in the table below:

FEC

Demod

Code

Data

Acq

On/Off

Descram

Buf

Inv

Misc

C-in-C

(Forward Error Correction) This sub-menu permits the user to select the method of FEC used for reception (Viterbi, TPC, etc.). FEC type takes the highest configuration priority.

(Demodulation) This sub-menu permits the user to select the modulation type used for reception (BPSK, QPSK, 8-PSK, etc.). The available choice of demodulation will depend on the FEC type chosen.

(FEC Code Rate) This sub-menu permits the user to select the FEC Code Rate used for reception (Rate 1/2, Rate 3/4, etc.). The available choice of Code Rate will depend on both the FEC type and Demodulation selected.

(Data Rate) This sub-menu permits the user to select the receive data rate, in steps of 1 bps. The choice of data rate will depend on the FEC type, Demodulation, and Code Rate selected.

(Acquisition) This sub-menu permits the user to determine the amount of frequency uncertainty the demodulator will search over in order to find and lock to an incoming carrier.

This sub-menu permits the user to control the output state of the transmit carrier.

(Descrambler) This sub-menu permits the user to select whether or not data descrambling is used.

(Buffer) This sub-menu permits the user to select whether or not the Plesiochronous/Doppler buffer is used, and if so, the size of that buffer.

(Inversion) This sub-menu permits the user to invert the sense of the received spectrum, or to invert the sense of the received baseband data.

(Miscellaneous) This sub-menu will allow the user to select Eb/No Alarm Threshold (EbNo) and Rx roll-off (alpha) factor Rxα.

(Carrier-in-Carrier→) This sub-menu allows the user to set-up the carrier-in-carrier parameters.

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