Impact of satellite transponder nonlinearities on the performance of protected tactical waveform (PTW) for the return link (RL).

This paper examines the impact of satellite transponder nonlinearities on the performance of protected tactical waveform (PTW) for the return link (RL). The performance impact due to adjacent channels interference (ACI) and a partial band noise jammer (PBNJ) are considered in the paper. In this paper, a Shaleh model is used to model the transponder traveling wave tube amplifier (TWTA). This TWTA is protected by a soft limiter to prevent TWTA operation in the saturation region. Impact of signal clipping due to this soft limiter under a PBNJ is also investigated. Computer simulations are performed using Digital Video Broadcasting - Satellite - Second generation (DVB-S2) forward error correcting (FEC) codes. In addition, a ground hub receiver does not assume knowledge of the channel information. Ground hub is required to estimate signal-to-noise ratio (SNR) and details of SNR estimation are also discussed in the paper.