Powerful nonlinear countermeasures for multicarrier satellites: progression to 5G

Abstract

The exigent demand for transmitting high data rates over satellites, coupled with the challenge to maximize satellite mass efficiency, has necessitated that multiple carriers with high-order modulation share the same transponder's high-power amplifier (HPA) that is operated close to saturation. Several powerful technological solutions, applied at the transmitter, in the form of predistortion, and at the receiver, in the form of equalization, are explored in this chapter to minimize the resulting nonlinear distortion. To establish greater commonality with the emerging fifth-generation (5G) ecosystem, the second part of this chapter endeavors to apply orthogonal frequency-division multiplexing (OFDM) signaling for broadband satellite transmission in the forward direction, namely, from the gateway to terminals. 5G terrestrial systems continue to use OFDM air interface. The aforementioned powerful countermeasures are then generalized, utilized, and shown to exhibit excellent performance in allowing OFDM-based satellite systems to be competitive with, and in some cases surpassing, traditional systems that use single-carrier modulation (SCM) when employing high-order constellations and/or having multiple signals share the same transponder.