Joint Uplink-Downlink Resource Allocation for OFDMA-URLLC MEC Systems

• Main Authors: Ghanem, Walid R, Jamali, Vahid, Zhang, Qiuyu, Schober, Robert
• Format: Journal Article
• Language: English
• Published: 10-05-2020
• Subjects: Computer Science - Information Theory; Mathematics - Information Theory
• DOI: 10.48550/arxiv.2005.04707

In this paper, we study resource allocation algorithm design for multiuser
orthogonal frequency division multiple access (OFDMA) ultra-reliable low
latency communication (URLLC) in mobile edge computing (MEC) systems. To
achieve the stringent end-to-end delay and reliability requirements of URLLC
MEC systems, we propose joint uplink-downlink resource allocation and finite
blocklength transmission. Furthermore, we propose a partial time overlap
between the uplink and downlink frames to minimize the end-to-end delay, which
introduces new time causality constraints. Then, the proposed resource
allocation algorithm is formulated as an optimization problem for minimization
of the total weighted transmit power of the network under constraints on the
minimum quality-of-service regarding the number of computed URLLC user bits
within the maximum allowable computing time, i.e., the end-to-end delay of a
computation task. Due to the non-convexity of the optimization problem, finding
the globally optimal solution entails a high computational complexity which is
not tolerable for real-time applications. Therefore, a low-complexity algorithm
based on successive convex approximation is proposed to find a high-quality
sub-optimal solution. Our simulation results show that the proposed resource
allocation algorithm design facilitates the application of URLLC in MEC
systems, and yields significant power savings compared to a benchmark scheme.