A new perspective on satellite communications via incompatible signal polarization features and wavefront multiplexing techniques

In this paper, we propose a technical solution to a realistic yet unanswered market question for the satellite communications industry: how can Ku-band satellites be designed to service increasing number of VSAT (very-small-aperture-terminal) users in FSS (fixed satellite service) market with lower cost? We first notice that economic considerations have dictated the transition of satellite communications services among different frequency bands. The short-term demand for capacity drives the potentially increased use of Ka-band satellites. However, Ku-band satellite transponder enjoys lower cost as compared with its Ka-band counterpart. There are many Ku-band linearly polarized (LP) satellites covering different service areas for fixed satellite services (FSS), which constitute the majority source of revenue in satellite services. On the other hand, circularly polarized (CP) terminals, some of which have been serviced by Ka-band satellites, are more economical in manufacturing and installations as compared with compatible LP terminals. The major bottleneck is the concurrent use of CP and LP formats in conventional communication systems. In this paper we present a class of WaveFront (WF) Multiplexing (muxing) techniques that revitalize CP-to-LP and LP-to-CP links and enable satellite operators to cost-effectively service VSAT users employing CP waveforms, either fixed or mobile, via Ku band LP transponders. Coherent power allocation becomes feasible for satellite communications between assets using incompatible polarization and WF muxing. WF muxing makes it operational for CP VSAT terminals to access LP or CP space assets equally well. WF muxing also allows satellite transponders, either in LP or CP format, to concurrently service both LP user and CP user communities equally well for spectrum efficiency.