Comtech EF Data SDM-650B - Manual (Page 132)

Theory of Operation SDM-650B Satellite Modem
5–8 Rev. 6
5.2.1 Specification
Demodulator Processor
Operating Symbol Rate Range 32 Ks/s to 2048 Ks/s
Operating Code Rate Range 7/8, 3/4, 1/2
Input Signal 11 Level Quantized I and Q
Output Signals VCXO Drive, AGC Drive, I sign, I mag,
Q sign, Q mag, Symbol, Clock, Data Clock
Carrier Phase Error ± 3° max.
Carrier Loop Bandwidth Software controlled
Clock Phase Error ± 5%
Clock Loop Bandwidth Software controlled
Clock Jitter 5% P-P max.
Sequential Decoder
Bit Error Rate See Chapter 1
Maximum Data Rate 2.1 Mbit/s (Rate 1/2)
3.2 Mbit/s (Rate 3/4 and 7/8)
Synchronization Time 19000 bits, max.
Output Fault Indicators Activity detection of I and Q data
Sign bits and descrambler data
Raw BER Detection From 0 to 255 bits out of 1024 samples
Descrambling V.35 or none
Differential Decoding 2 phase
I/O Connector DIN, -96-pin