Joint Rate Control and Power Allocation for Non-Orthogonal Multiple Access Systems

Abstract

Abstract-This paper investigates the optimal resource allocation of a downlink non-orthogonal multiple access (NOMA) system consisting of one base station and multiple users. Unlike existing short-term NOMA designs that focused on the resource allocation for only the current transmission timeslot, we aim to maximize a long-term network utility by jointly optimizing the data rate control at the network layer and the power allocation among multiple users at the physical layer, subject to practical constraints on both the short-term and long-term power consumptions. To solve this problem, we leverage the recently-developed Lyapunov optimization framework to convert the original long-term optimization problem into a series of online rate control and power allocation problems in each timeslot. The power allocation problem, however, is shown to be non-convex in nature and thus cannot be solved with a standard method. However, we explore two structures of the optimal solution and develop a dynamic programming based power allocation algorithm, which can derive a globally optimal solution, with a polynomial computational complexity. Extensive simulation results are provided to evaluate the performance of the proposed joint rate control and power allocation framework for NOMA systems, which demonstrate that the proposed NOMA design can significantly outperform multiple benchmark schemes, including orthogonal multiple access (OMA) schemes with optimal power allocation and NOMA schemes with non-optimal power allocation, in terms of average throughput and data delay.

A Survey on Non-Orthogonal Multiple Access for 5G Networks: Research Challenges and Future Trends

“…In [97], the energy efficiency of NOMA is investigated, where power allocation and subchannel assignments are jointly designed by applying the difference of convex (DC) programming method. In [98], a queuing theoretic approach for joint rate control and power allocation is proposed. In [99], the system throughput maximization problem is studied for both uplink and downlink NOMA, where power allocation and user clustering are optimized in an alternating manner.…”

Joint rate control and power allocation for low-latency reliable D2D-based relay network

“…It is noticed that there exist long-term constraints in original problem P1. To handle the long-term time-average power consumption constraint, C 4 can be transformed into queue stability constraint by employing virtual queue [25]. The virtual queue is defined as Z(t) = {Z 1 (t), · · · , Z m (t), · · · , Z M (t)}, and Z m (t) evolves as follows:…”

Unified User Association and Contract-Theoretic Resource Orchestration in NOMA Heterogeneous Wireless Networks

“…Towards overcoming the drawbacks of fixed power allocations, dynamically adjusted power allocation schemes were designed in [16], [17] for two-user and multipleuser NOMA systems, respectively. Based on this groundwork, more recent efforts targeted at addressing various joint resource allocation problems in NOMA-based networks, such as joint rate and power control [18], and joint spectrum and power control [19].…”