DeepAI AI Chat
Log In Sign Up

Cooperative Asynchronous Non-Orthogonal Multiple Access with Power Minimization Under QoS Constraints

by   Xun Zou, et al.

Recent studies have demonstrated the superiority of non-orthogonal multiple access (NOMA) over orthogonal multiple access (OMA) in cooperative communication networks. In this paper, we propose a novel half-duplex cooperative asynchronous NOMA (C-ANOMA) framework with user relaying, where a timing mismatch is intentionally added in the broadcast signal. We derive the expressions for the individual throughputs of the strong user (acts as relay) which employs the block-wise successive interference cancellation (SIC) and the weak user which combines the symbol-asynchronous signal with the interference-free signal. We analytically prove that in the C-ANOMA systems with a sufficiently large frame length, the strong user attains the same throughput to decode its own message while both users can achieve a higher throughput to decode the weak user's message compared with those in the cooperative NOMA (C-NOMA) systems. Besides, we obtain the optimal timing mismatch when the frame length goes to infinity. Furthermore, to exploit the trade-off between the power consumption of base station and that of the relay user, we solve a weighted sum power minimization problem under quality of services (QoS) constraints. Numerical results show that the C-ANOMA system can consume less power compared with the C-NOMA system to satisfy the same QoS requirements.


An Analysis of Uplink Asynchronous Non-Orthogonal Multiple Access Systems

Recent studies have numerically demonstrated the possible advantages of ...

Rate-Splitting Multiple Access for Cooperative Multi-Cell Networks

As a promising downlink multiple access scheme, Rate-Splitting Multiple ...

Interference-aware User Grouping Strategy in NOMA Systems with QoS Constraints

To meet the performance and complexity requirements from practical deplo...

Novel Time Asynchronous NOMA schemes for Downlink Transmissions

In this work, we investigate the effect of time asynchrony in non-orthog...

Max-Min Fairness Based on Cooperative-NOMA Clustering for Ultra-Reliable and Low-Latency Communications

In this paper, the performance of a cooperative relaying technique in a ...

Asymptotic Performance Analysis of NOMA Uplink Networks Under Statistical QoS Delay Constraints

In this paper, we study the performance of an uplink non-orthogonal mult...

RIS-Assisted Cooperative NOMA with SWIPT

This paper studies the application of reconfigurable intelligent surface...