Hybrid Multicast/Unicast Design in NOMA-based Vehicular Caching System with Supplementary Material

TL;DR

This paper proposes a hybrid multicast/unicast scheme for NOMA-based vehicular caching systems, optimizing unicast sum rate under practical constraints and demonstrating superior performance over traditional methods.

Contribution

It introduces a novel hybrid multicast/unicast design for NOMA vehicular systems considering imperfect CSI and formulates an optimization approach for enhanced performance.

Findings

Proposed scheme outperforms orthogonal multiple access in simulations.

Effective optimization method divides complex problem into convex sub-problems.

Hybrid scheme improves unicast rate under realistic vehicular channel conditions.

Abstract

In this paper, we investigate a hybrid multicast/ unicast scheme for a multiple-input single-output cache-aided non-orthogonal multiple access (NOMA) vehicular scenario in the face of rapidly fluctuating vehicular wireless channels. Considering a more practical situation, imperfect channel state information is taking into account. In this paper, we formulate an optimization problem to maximize the unicast sum rate under the constraints of the peak power, the peak backhaul, the minimum unicast rate, and the maximum multicast outage probability. To solve the formulated non-convex problem, a lower bound relaxation method is proposed, which enables a division of the original problem into two convex sub-problems. Computer simulations show that the proposed caching-aided NOMA is superior to the orthogonal multiple access counterpart.