Hughes HX System User Manual

Chapter 8 • Transmission features
64
1037852-0001 Revision A
Inbound channel:
adaptive coding
The Hughes system can dynamically change the coding rate of
the inbound channel. This feature significantly improves link
availability. As shown in
Figure 14, this feature enables the return
channel demodulators (RCD) at the HX gateway to demodulate,
decode, and process bursts of varying coding rates within the
same TDMA frame. The gateway demodulator does not need to
know the coding of each burst in advance. The coding rate is
determined spontaneously, allowing the satellite router to
dynamically change it based on link conditions, as affected by
rain fade.
Figure 13: Using ACM to dynamically change coding/modulation
Figure 14: Multiple FECs within one TDMA frame

Hughes HX System Specifications

General

Brand	Hughes
Model	HX System
Category	Receiver
Language	English