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Table B-5. Data Configuration Constraints for DG2, Single Data Source (SQPSK)
Source Data Rate Restrictions and
Coding Data
Availability (note 1)
Configuration
(note 5) Format
KuSA and
MA SMA SSA
KaSA
1 kbps - 1 kbps - >10 Mbps -
Alternate I and Q
NA 3 Mbps 6 Mbps 75 Mbps
bits (note 2)
Rate 1/2 NRZ
(note 3) (note 3) (note 6)
Alternate I and Q
1 kbps - 1 kbps - 1 kbps -
symbols
300 kbps 300 kbps 10 Mbps
1 kbps - 1 kbps -
Alternate I and Q
Rate 1/3 NRZ
NA 2 Mbps 2 Mbps NA
bits (note 2)
(note 3) (note 3)
Alternate I and Q
1 kbps -
Uncoded NRZ
NA Note 4 Note 4
bits (note 2)
300 Mbps
Notes:
1. For SQPSK modulation, the I/Q (power) = 1:1 and
the I channel data rate = Q channel data rate = 1/2 the source data rate.
2. For the alternate I and Q bit configuration, the data format must be NRZ-L. On each
channel, the data bits are identically but independently and differentially encoded and
then convolutionally encoded (if desired) prior to transmission.
3. Periodic convolutional interleaving (PCI) recommended on SMA and SSA return service
for baud rates > 300 kbps. When interleaving is not employed for baud rates > 300
kbps, SSA and SMA performance may not be guaranteed.
4. The SN is capable of supporting SMA and SSA uncoded return link signals; however, its
use will be constrained and must be coordinated with GSFC Code 450.
5. Figure B-10 describes the convolutional encoders supported by the SN.
6. For rate 1/2 coding and source data rates greater than 20 Mbps (i.e., channel data rates
greater than 10 Mbps), the customer transmitter must be configured to use N-parallel
encoders, where N is the number of branch rate 1/2 encoders for each of the I and Q
channels. N = channel data rate in bps/1x10 7 , where N is rounded to the next higher
integer if N is not an integer.
e. Unbalanced Power Dual Data Sources (SMA or SSA only). The I and Q
channels consist of independent data that is independently formatted,
convolutionally coded (if applicable), and symbol interleaved (if applicable).
The signal is transmitted using unbalanced (I/Q power ratio is 4:1) QPSK or
SQPSK modulation. Table B-7 lists the service configuration constraints, where
the source data rate constraints apply to each channel separately. The data
conditioning operations supported are shown in Figure B-8 for this
configuration, where the channel data source represents each of the I and Q
channel sources separately for independent data conditioning operations.
Figure B-10 describes the convolutional encoders supported by the SN.
Revision 10 B-21 450-SNUG