Array detector systems for satellite-to-ground atmospheric coherent laser communications: performance evaluation

Satellite-to-ground coherent laser communication is constrained by atmospheric turbulence. Although array detection can mitigate atmospheric turbulence, outdoor experiments are expensive and difficult to conduct. This study presents a satellite-to-ground optical communication downlink model using equivalent Rytov index-interval phase screens with a non-Kolmogorov power spectrum to simulate atmospheric turbulence between satellites and ground stations. The performance of single and array detector systems was evaluated based on mixing efficiency (ME) and bit error rate (BER). The results demonstrated that array detectors enhanced both ME and BER performance, with the coherent ME increasing approximately linearly with the number of unilateral array elements. The methodologies presented in this study serve as valuable tools for forecasting communication-link budgets and establishing optical system design requirements in satellite-to-ground atmospheric coherent laser communications.