Novel Pilot Allocation Random Access Protocol for Integrated Terrestrial-Satellite Networks

In this paper, we propose a novel pilot allocation with desired reliability (PA-DR) random access protocol for integrated terrestrial-satellite network (ITSN). ITSN is regarded as an effective solution to achieve massive connectivity and ubiquitous coverage in future communication systems. To provide massive machine type communications (mMTC) to a backbone satellite in ITSN, the dense user equipments (UEs) are permitted to jointly transmit randomly chosen pilot sequences along with their data packets over multi-slot in our PA-DR random access protocol, which allows for the potential performance gain in resolving more intra-cell pilot collisions with high probability. By utilizing the finite length analysis of pilot allocation over muti-slot, we derive the closed-form expressions to the access failure probability and system throughout in the finite length regime, which is highly desired for practical-interest ITSN. With the help of the derived expressions, we propose a guideline for mMTC ITSN that target on satisfying desired reliability of UEs, and optimize the number of allocated pilots and minimum access latency under diverse access failure probability requirements. In addition, simulation results show that our PA-DR random access protocol outperforms the existing protocols in achieving high throughput and shortening the access latency.