Using DVB-S2 over asymmetric heterogeneous optical to radio frequency satellite links

Abstract

The DVB-S2 coding standard has seen widespread use in many radio frequency (RF) communications applications. The availability of commercial-off-the-shelf (COTS) intellectual property (IP) that can be used to rapidly prototype and field communications systems makes this well-performing, standards-based approach to forward error correction (FEC) coding extremely attractive. In this paper, we evaluate the application of the DVB-S2 coding standard to an asymmetric satellite communications channel. The uplink comprises a fading optical link employing binary differential phase-shift keyed (DPSK) modulation, while the downlink comprises an RF link employing 16-ary amplitude and phase shift keyed (16-APSK) modulation. To simplify the payload implementation, hard-decision uplink demodulation is considered with uplink channel state information transmitted on the downlink for soft-decision decoding in the ground-based receiver. Additionally, we outline many of the trade offs in the overall system design, and some performance results of a baseline design are presented.

Update on NASA’s Laser Communications Relay Demonstration Project

“…While coding and interleaving will be applied in the ground terminal to mitigate noise and atmospheric fading, the DPSK flight receiver does not decode nor de-interleave. The modems instead support a relay architecture where upand down-link errors are corrected together in a decoder located at the destination ground station [4].…”

Overview of the Laser Communications Relay Demonstration Project

“…While coding and interleaving will be applied in the ground terminal to mitigate noise and atmospheric fading, the DPSK flight receiver does not decode nor de-interleave. The modems instead support a relay architecture where upand down-link errors are corrected together in a decoder located at the destination ground station [6].…”

Incorporation of Uplink Channel State Information into an End-to-End Coded Satellite Communication System

“…code where both the uplink and downlink demodulator produce hard decisions is shown in Fig. 6, compared to the channel capacity from (1). Channel state information is not available for either the uplink or the downlink in this configuration.…”

“…l shows a block diagram of a satellite communications system where coding and decoding is implemented at the user terminals ("end-to-end coding"), and the signal is simply demodulated and remodulated on board the satellite. This simplifies the payload processing and also allows a more powerful code to be implemented at the user terminals than what could be practically implemented on board the satellite [1). To approach channel capacity in an end-to-end coded system, it is necessary to incorporate the uplink channel state information for each channel bit at the receiver.…”