Specifications

SDM-100A Satellite Modem Theory of Operation
Rev. 0 4–5
4.1.2 Specifications
Modulation Type QPSK or BPSK
Data Rate Range 19.2 to 128 kbit/s 1/2 Rate, QPSK
28.8 to 192 kbit/s 3/4 Rate, QPSK
33.6 to 224 kbit/s 7/8 Rate, QPSK
9600 bit/s to 64 kbit/s 1/2 Rate, BPSK
Symbol Rate Range 19.2 to 128 ks/s
Test Modes Carrier Null and Quadrature (Dual and Offset)
Frequency Range 50 to 180 MHz
Frequency Select Method Synthesized
Frequency Step Size 2.5 kHz
Frequency Stability (RF) ± 10 PPM Internal Oscillator
Frequency Stability (SCT) ± 10 PPM Internal Oscillator
Phase Error 2.5° max.
Filtering Type Nyquist, Pre-equalized
Spectral Occupancy Spectral Density is -30 dB at ± 0.75 Symbol Rate
Spurious and Harmonics -55 dBc, 0 to 500 MHz
Output Power Level Range -5 to -30 dBm, ± 0.5 dB
Output Stability ± 0.5 dB
Output Power Adjustment 0.5 dB step size
Output Impedance 75Ω, 50Ω optional
Output Return Loss 20 dB minimum
Scrambling V.35
FEC Encoding Convolutional K = 7 Viterbi, or Sequential Encoding
Decoding Soft-Decision Viterbi or Sequential Rate 1/2, 3/4, or 7/8
Reported Faults AGC Level Fault
Synthesizer Fault
I Channel Filter Activity
Q Channel Filter Activity
Clock Activity Fault