Abstract:
To meet the futuristic communications needs, a satellite-terrestrial integrated network
(STIN) has been proposed and is a strong contender amongst emerging architectures.
Different approaches have been researched and mainly two models are being considered
for STIN implementation. In our STIN model, we have considered a satellitebased
base station, dovetailed with a terrestrial N-tier heterogeneous network (HetNet).
Joint admission control, user association (UA), and power allocation while ensuring
fairness while associating user equipment (UE) in STIN and fairness in the allocation
of spectrum resources to associated UEs in STIN with an objective to maximize
throughput has not been investigated in the past. Classically, a macro base station
(MBS) has the maximum resources as compared to small base stations and in HetNets
a UE associates with a single BS depending upon the received signal strength. Consequently,
most UEs are expected to be associated with a dominant transmit power
MBS which is not an optimal approach as various new challenges arise such as unfair
traffic load and interference resulting in overall reduced throughput. In the proposed
approach, we have made an endeavor to meet these challenges and formulated a
throughput maximization problem considering joint admission control, fair UA, power,
and fair spectrum resource allocation. The formulated problem is a mixed integer nonlinear
programming (MINLP) problem that is non-deterministic polynomial-time hard
(NP-hard) and to achieve an optimal solution it requires exhaustive search. But, the
computational load of exhaustive search increases exponentially as the number of UEs
increases. Therefore, to obtain a near-optimal solution having low computational load
an outer approximation algorithm (OAA) is proposed. To evaluate the proposed algorithm, extensive simulation work has been performed. The effectiveness of the proposed approach is verified by the results in terms of fairness in UA, fairness in resource block (RB) allocation, and throughput in the downlink (DL).
