On the Performance of Hybrid Satellite-Terrestrial Content Delivery Networks With Non-Orthogonal Multiple Access

Abstract

Wireless content delivery (CD) and non-orthogonal multiple access (NOMA) have been confirmed to be promising and effective approaches to gain substantial performance improvement for hybrid satellite-terrestrial (HST) networks. To improve the spectrum efficiency and reduce the delay of retrieving the content for the satellite user, we investigate the performance of the HST-CD network with the NOMA scheme, where the satellite proactively pushes/broadcasts the popular contents to the cache-enabled relay, and then the user is able to directly retrieve the required content from the relay with less transmission delay. Specifically, based on the practical propagation model along with the stochastic geometry, the outage probability for the cache-enabled relays of the considered network is theoretically derived. Besides, the hit probability of the user in the HST-CD network is also provided. Finally, both simulation and analytical results are provided to validate the effect of the HST-CD network with the NOMA scheme and proclaim the influence of key factors on the performance.