Effects of differential oscillator phase noise in precoding performance

Satellite precoding is a promising technique to meet the target data rates of the future high throughput satellite systems and the costs per bit as required by 5G applications and networks, but it requires strict synchronization among the transmitted waveforms, in addition to accurate channel state information. Most of the published work about this topic consider ideal oscillators, but in practice, the output of an oscillator is not a single spectral line at the nominal frequency. This chapter proposes a model for the oscillator phase noise and analyzes the resulting received signal to interference plus noise ratio (SNIR) in a satellite communication system using precoding. Simulations of a communication satellite system with a two-beam transponder and two receivers were performed to compute the effective SNIR. This work uses a simulator which also considers practical impairments such as time misalignment, errors in the channel state information, interference, thermal noise, and phase noise masks for satellite oscillators. The precoding methods used for the analysis are zero forcing (ZF) and minimum mean square error (MMSE). The obtained results prove that there is a degradation in the performance due to the use of independent oscillators but this effect is compensated by the precoding matrix.