Joint Resource Optimization Method Based on Downlink of Underwater Acoustic Ofdm-Noma System

Abstract

The present invention proposes an underwater acoustic OFDM-NOMA downlink joint resource optimization method to solve the problem that there is no feasible underwater non-orthogonal multiple access network resource allocation mechanism in the prior art. Firstly, an underwater acoustic wireless communication system based on OFDM-NOMA is established. The system deploys a base station BS and K anchor nodes, and the channel information status of each anchor node is known; given constraints: the total transmit power of the base station Pt, the subcarrier allocation Quantity constraints; the objective function is the sum of the system rates. To solve the joint resource optimization problem, the proposed optimization problem is completed step by step. The sub-carrier allocation adopts a greedy algorithm with low algorithm complexity to meet the optimization goal of the system sub-carrier allocation. For power allocation, the optimization target is transformed from transmission power to communication rate, the power allocation model is transformed into a strict convex optimization problem, and the optimal value is solved by using GP algorithm. The invention is scientific and reasonable, has low algorithm complexity, and is suitable for harsh underwater communication environments.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, and in particular relates to an underwater acoustic OFDM-NOMA system-based downlink joint resource optimization algorithm. Background technique [0002] Underwater acoustic channels are considered to be one of the most challenging communication channels. It has a series of characteristics such as fast time variation, large transmission attenuation, limited communication bandwidth, Doppler effect and serious multipath delay expansion, and large propagation delay. This brings great challenges to underwater wireless sensor networks, especially physical layer multi-user underwater acoustic communication. Multi-user underwater acoustic communication is divided into two modes: uplink communication and downlink communication. In the uplink, the base station receives multiple signals from different users at the same time; in the downlink, the base station sends signals to each user in th...

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Problems solved by technology

[0006] Aiming at the problem that there is currently no feasible non-orthogonal multiple access network resource allocation mechanism in harsh environments such as underwater, the present invention proposes a combination of subcarriers and power based on the downlink of the non-orthogonal multiple access system Optimized algorithm, taking into account the principle of fairness in bit error rate and resource allocation, rationally allocate subcarrier resources and power resources, and provide higher system capacity

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