OFDMA wireless multi-hop network resource allocation method based on graph theory

Abstract

The invention discloses an OFDMA wireless multi-hop network resource allocation method based on a graph theory. The OFDMA wireless multi-hop network resource allocation method based on the graph theory mainly solves the problem that the use ratio of resources is low when link subcarrier allocation is carried out in the prior art. The OFDMA wireless multi-hop network resource allocation method based on the graph theory comprises the steps that (1) a topological graph of a wireless multi-hop network is generated, a service route matrix is generated according to the topological graph and service flow in the graph, rates required by all links are acquired, the number of subcarriers required by each link is calculated according to single carrier rates, subcarriers of the links are respectively pre-allocated according to a coloring theory to acquire a combinatorial link matrix; (2) through a repeated Hungary algorithm, the subcarriers are allocated to each line combination of the combinational matrix, rates of the subcarriers on each link of each line combination are added to acquire the transmission rate of each line combination, and the transmission rates of all line combinations are added to acquire a total transmission rate. The OFDMA wireless multi-hop network resource allocation method based on the graph theory achieves the reuse of frequency resources and the optimum allocation of the carriers, ensures that all links are not interrupted with each other, and has the advantages of being high in resource use ratio.

Description

technical field [0001] The invention belongs to the technical field of communication, and further relates to resource allocation in an OFDMA wireless multi-hop system, which can be used to allocate subcarriers to links. Background technique [0002] In an OFDMA wireless cellular communication system, since the number of links is usually smaller than the number of subcarriers to be transmitted, the allocation of different subcarriers on different links will produce a certain rate gain. The allocation scheme of limited subcarrier resources has a great impact on the performance of the system. The existing resource allocation methods mainly include: proportional fairness method, Hungarian algorithm, and maximum value method. [0003] In the patent "Subcarrier Allocation Method for Multi-Carrier Wireless Communication System" (Patent Application No. 200510115002, Publication No. CN1972266A) applied by Siemens (China) Co., Ltd., a sub-carrier allocation method in a multi-carrier ...

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Problems solved by technology

The disadvantage of this method is: since the control node monitors the impulse response power of the wireless channel on the sub-band used by the user terminal, in the case of relatively large traffic, it needs to allocate channels frequently, which consumes a lot of resources. The resource utilization of the situation also needs to be improved

The basic idea of ​​the proportional fair method is to use the formula given in the paper to determine the proportional coefficient of each link, then convert the rate matrix of subcarriers and links into a square matrix according to the proportional coefficient, and finally use the Hungarian algorithm for final allocation , but the determination of its proportionality coefficient is only limited to the case where the matrix element is greater than 1. According to the literature [2] Ioannis G. Fraimis, Stavros A. Kotsopoulos "QoS-Based Proportional Fair Allocation Algorithm for OFDMA Wireless Cellular Systems" (IEEE COMMUNICATIONS LETTERS, The method of determining the link rate matrix proposed in VOL.15, NO.10, OCTOBER2011)] will get the situation that the elements of the link rate matrix are all less than 1, at this time the proportional fairness method is not applicable, and because the proportional coefficient Converting the matrix into a square matrix, increasing the size of the matrix will increase the computational complexity, and the resource utilization rate is not high

[0005] The above algorithms are all based on resource allocation in a single-hop system, without considering frequency reuse and co-channel interference in a multi-hop system

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