Mobility enhancement for digital video broadcast networks via satellite

The DVB-S2 standard has been optimised for provision of broadband multimedia services to geographically dispersed fixed satellite end-users under line-of-sight (LOS) channel condition. However, continuing growth in demand for mobile broadband services via satellite necessitates a detailed examination of the DVB-S2 technology to assess its suitability for application in the mobile satellite environment. The environment is affected by signal fading due to path blockage, multipath propagation and shadowing, Doppler shift which is expressed by the Rician channel K-factor parameter values. In this paper, a model was developed in MATLAB® to simulate transmission scenarios through a mobile satellite channel, in order to investigate the bit-error-rate (BER) performance of the 16-APSK and 32-APSK modulation formats for different coding rates. This modelling of higher modulation formats of the DVB-S2 standard until now, has not been addressed adequately in related literature. Moreover, the mobility effect over the BER performance is not well investigated in the literature especially for high modulation schemes. Results obtained by simulation indicate a significant degradation in the system's BER when compared to a line-of-sight channel condition. Which even becomes worse with added varying mobility scenarios. However, higher Rician channel K-factor values tend to improve the link quality closer to that of the AWGN. These results highlight a crucial need to develop improved receiver processing and new switching thresholds applicable to the mobile satellite environment that deliver improved link availability as well as enhanced data throughput for different mobility scenarios.