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Link Modulation Configurations. The following slides summarize the possible configurations for the following four carrier types Forward link Remnant (residual) carrier Supressed carrier Return Link Remnant (residual) carrier Supressed carrier. Remnant (Residual) Forward Carrier.
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Link Modulation Configurations • The following slides summarize the possible configurations for the following four carrier types • Forward link • Remnant (residual) carrier • Supressed carrier • Return Link • Remnant (residual) carrier • Supressed carrier
Remnant (Residual) Forward Carrier • Mod index = 100 - 1560 milliradians • PM carrier modulation is CCSDS 401-standard and is supported by CCSDS Space Communication Cross Support Service Management (SCCS-SM) Blue-1 • FM, AM carrier modulation are also possible, but not CCSDS standard (and not supported by SCCS-SM Blue-1) • Data may be modulated directly onto the carrier (PCM/PM) • Data may be modulated onto a single PSK-modulated subcarrier (PCM/PSK/PM) • Single subcarrier is CCSDS 401 standard and is supported by SCCS-SM Blue-1 • Multiple subcarriers are possible but not 401-standard and not supported by SCCS-SM Blue-1 • For CCSDS 401, data are modulated onto either the remnant carrier or the subcarrier at any given time, not both simultaneously. This restriction is inherent in SCCS-SM Blue-1 • Concurrent modulation of carrier and subcarrier(s) is possible, but not 401-standard and not supported by SCCS-SM
Supressed Forward Carrier • Mod index = 1561 - 1571 milliradians • BPSK carrier modulation is CCSDS 401 standard and is supported by SCCS-SM Blue-1 • QPSK carrier modulation may become CCSDS standard in the future, but not CCSDS standard now (and not supported by SCCS-SM Blue-1) • Data must be modulated directly onto the carrier (PCM/BPSK) • No subcarrier(s) are available with supressed forward carriers
Remnant (Residual) Return Carrier • Mod index = 100 - 1560 milliradians • PM carrier modulation is CCSDS 401 standard and is supported by CCSDS Space Communication Cross Support Service Management (SCCS-SM) Blue-1 • FM, AM carrier modulation are also possible, but not CCSDS standard (and not supported by SCCS-SM Blue-1) • Data may be modulated directly onto the carrier (PCM/PM) • Data may be modulated onto a single PSK-modulated subcarrier (PCM/PSK/PM) • Single subcarrier is CCSDS 401 standard and is supported by SCCS-SM Blue-1 • Multiple subcarriers are possible but not 401-standard and not supported by SCCS-SM Blue-1 • For CCSDS 401, data are modulated onto either the remnant carrier or the subcarrier at any given time, not both simultaneously. This restriction is inherent in SCCS-SM Blue-1 • Concurrent modulation of carrier and subcarrier(s) is possible, but not 401-standard and not supported by SCCS-SM
Supressed Return Carrier • Mod index = 1561 - 1571 milliradians • BPSK, QPSK, OQPSK, UQPSK, and GMSK carrier modulation are CCSDS 401 standard and are supported by SCCS-SM Blue-1 • Data must be modulated directly onto the carrier (PCM/BPSK, PCM/QPSK, PCM/OQPSK, PCM/UQPSK, or PCM/GMSK) • No subcarrier(s) are available with supressed return carriers