Table of Contents
Advertisement
SLM-7650 Satellite Modem
Introduction
1.2.1
Definition of Modulator Functions
The modulator section accepts data and clock from a digital signal source and after
appropriate processing modulates the information on an IF carrier. The modulator
provides the following functions:
1. Interface that receives digital signals, including data, clock, frequency reference, and
control from a digital signal source.
2. A function that scrambles the data.
3. A differential encoder.
4. Forward Error Correction (FEC) encoding.
5. Perform BPSK, QPSK, OQPSK, 8-PSK, and 16-QAM modulation.
6. An output IF signal.
7. Setup, control, monitoring, and upgrade of the modulator.
8. Built-in Test (BIT) function that detects fault conditions and allows faults to be
isolated to the modulator. This includes provision for an IF loopback and a transmit
interface test data pattern.
1.2.2
Definition of Demodulator Functions
The demodulator section accepts a signal from an Intermediate Frequency (IF) carrier,
demodulate the IF carrier, and after appropriate processing, outputs the data and clock to
the user. The demodulator provides the following functions:
1. An input for the IF signal.
2. Acquisition functions and a function to demodulate BPSK, QPSK, OQPSK, 8-PSK,
and 16-QAM carriers.
3. Forward Error Correction (FEC) decoding.
4. A differential decoder.
5. Descrambles the received data.
6. Digital interface to output digital signals, including data, and associated clock.
7. Setup, control, monitoring, and upgrade of the demodulator.
8. Built-in Test (BIT) function that detects fault conditions and allow faults to be
isolated to the demodulator. This includes provision for an IF loopback and a way to
measure the error using a test data pattern.
1–3
Revision 4
MN/SLM7650.IOM
Advertisement
Table of Contents
