Exploiting Diversity in Future Generation Satellite Systems with Optical Feeder Links

Abstract

In this paper we exploit the transmitter micro diversity in the satellite communication systems with optical feeder links. Both analogue and digital transparent systems are studied. We consider up to four statistically independent transmitted optical beams with perfect or partial phase knowledge of the beams at the receiver. End-to-end simulation results for frame error rates are presented for a complete system including uplink, satellite payload and downlink. We compare our results with those of the DVB-S2 standard without the optical feeder link. Our results provide a complete view of gains and losses which can be obtained by micro diversity in both analogue and digital transparent satellite systems with optical feeder link. Given the system parameters, we also provide a detailed study of the transmitted power needed to achieve a target frame error rate and discuss the achieved bit rates in for each system scenario.

Ground‐to‐GEO optical feeder links for very high throughput satellite networks: Accent on diversity techniques

“…which is slightly different from the same relation found in Mengali et al 38 This is due to the fact that 38 assumed the input/output characteristic of the transmitter laser to relate input electrical amplitude to output light amplitude. In this work, instead, we have adopted the exact relationship where to an input electrical amplitude corresponds an output power (density).…”

“…In the traditional RC where the streams combine over the air, a power gain can be achieved when under streams add up coherently. However, as shown in Mengali et al, 38 the traditional RC scheme for optical feeder links performs poorly due to the possibility of destructive interference among the spatially separated streams. Hence, a viable diversity technique for the considered scenario, involves RC, but using additional resources.…”

“…Laser beams at the same frequency may combine destructively, leading to insufficient light reaching the receiving photodetector. The impact of random phase combination of the optical beams over lognormal channels has been analyzed in Mengali et al 38 where the noncoherent combination completely negates the benefits of RC. For this reason, most of the works analyzing spatial diversity in satellite optical feeder links assume frequency/polarization separation in addition to the spatial one in order to always achieve nondestructive combination.…”