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Martingales-based energy-efficient D-ALOHA algorithms for MTC networks with delay-insensitive/URLLC terminals co-existence
By : Saviour
Date : 2018-03-23
Views : 87

One of key features in machine type communications
(MTCs), especially for MTCs embracing ultra-reliable
and low latency communications (URLLCs), is the short packet
transmission with finite block-length. Both the feature of short
packet transmissions and the requirement on supporting LLCs
or URLLCs pose challenges to radio access design for MTC
networks in fifth generation (5G). In this paper, for the MTC
networks with delay-insensitive/URLLC terminals co-existence
scenarios, we propose the energy-efficient differentiated ALOHA
(D-ALOHA) random access algorithms, which simultaneously
achieve energy efficient and satisfy the requirements of URLLC
in a distributed mode. First, we abstract a service model of a
MTC terminal with joint consideration of the achievable rate for
short packet transmissions, the truncated channel inverse scheme,
and the D-ALOHA scheme. Based on the formulated service
model, then we derive the martingale parameters of service
process for each terminal, and analyse the delay-bound violation
probability of a terminal via the optimum stopping theory for
martingales. The martingales-based delay analysis is verified
via simulations. Finally, we formulate our energy-efficient DALOHA
algorithm as an energy efficiency maximization problem
with martingales-based statistical delay-quality of service (QoS)
constraints, and the resultant optimization problem (OP) is solved
by the invasive weed optimization-differential evolution (IWODE)
algorithm. Furthermore, we propose a sub-optimal but lowcomplexity
energy-efficient D-ALOHA scheme, which neglects
the distance difference of delay-insensitive terminals, such that
the same access probability are imposed on these terminals for
reducing the computational complexity of IWO-DE. Simulation
results demonstrate that the energy efficiency performance of
our D-ALOHA algorithms is favourite, and our D-ALOHA can
achieve URLLCs in case of short duration of a slot.
Attachment 1:   ÷ uRLLC.pdf(3.0MB)