Joint resource optimization method based on underwater acoustic OFDM-NOMA (Orthogonal Frequency Division Multiplexing-Non-Orthogonal Multiple Access) system downlink

Abstract

The invention provides a joint resource optimization method based on an underwater acoustic OFDM-NOMA (Orthogonal Frequency Division Multiplexing-Non-Orthogonal Multiple Access) system downlink and isused for solving a problem that in the prior art, no underwater non-orthogonal multiple access network resource allocation mechanism with high feasibility exists. An underwater acoustic wireless communication system based on OFDM-NOMA is established. A base station (BS) and K anchor nodes are deployed in the system. A channel information state of each anchor node is known. A constraint conditionis given. The constraint condition comprises a total transmitting power Pt of the base station and a constraint of subcarrier allocation number. A system rate sum is taken an objective function. In order to solve a joint resource optimization problem, the provided optimization problem is finished step by step. Subcarrier allocation is carried out through adoption of a greedy algorithm with relatively low algorithm complexity, so a system subcarrier allocation optimization objective is satisfied. For power allocation, an optimization objective is converted from a transmitting power to a communication rate, a power allocation model is converted into a strict convex optimization problem, and an optimum value is solved through adoption of a GP (Geometric Programming) algorithm. The method is scientific and reasonable, is low in algorithm complexity and is applicable to an underwater bad communication environment.

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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