Performance analysis of adaptive modulation system over mobile satellite channels

The performance of adaptive modulation system over satellite channels under Gaussian distribution, Rayleigh distribution and Rice distribution is analyzed and investigated according to the channel environment of satellite communication. A suitable adaptive modulation algorithm is proposed for the statistical properties of satellite channels comparing to the existing fixed modulation performance. The optimization criterion of the setting of the modulation switching levels is to maintain the target bit error rate (BER). BER analysis is performed and spectrum efficiency for adaptive modulation system at different SNRs is analyzed. The closed-form formulas of BER performance and spectrum efficiency are derived. The performance analysis of throughput and transmission outage probability of the proposed adaptive modulation system is presented. Finally, the simulation results show that the adaptive modulation system can theoretically achieve high throughput performance, and low transmission outage probability under satellite channel conditions.