Розробка математичної моделі управління пропускною здатністю низхідного каналу зв’язку технології LTE, що використовує перший вид розподілу ресурсів

Abstract

Наведено результати розроблення математичної моделі розподілу частотно-часового ресурсу низхідного каналу зв’язку технології LTE, що використовує перший вид розподілу ресурсів. Запропонована модель спрямована на забезпечення гарантованої якості обслуговування користувачів безпроводової мережі виділенням станціям користувачів необхідної пропускної здатності в низхідному каналі зв’язку. Проаналізовано запропоновану модель розподілу частотно-часового ресурсу технології LTE з погляду забезпечення необхідних пропускних здатностей різних станцій користувачів у низхідному каналі зв’язку. It was established that one of the main problems in the wireless network that operates using LTE, is the task of ensuring the required quality of service, which includes the need for the user equipment network bandwidth required in the downlink. Providing the required bandwidth can be achieved by solving the problems of distribution of a time-frequency resource in a downlink, which acts as resource blocks. As shown by the analysis known solutions for bandwidth allocation in the downlink LTE are oriented on the use of Resources Allocation Type 0, which has a low flexibility due to combination in the resource blocks group. The analysis decision on the need to develop a mathematical model of bandwidth management downlink LTE, using the first type of resource allocation is formulated as a problem of resource allocation sides, to provide the required bandwidth of each user equipment. As a result of this article proposed a mathematical model of the distribution bandwidth downlink LTE which novelty is the use of the Recourse Allocation Type 1. The calculation of the unknown variables in the model proposed in accordance with the conditions, it is advisable to carry out the limitations in solving optimization problems using an optimality criterion aimed at maximizing the overall performance of the downlink. The formulated problem from a mathematical point of view is a task Integer Linear Programming (ILP). In the model the desired variables are boolean, and restrictions on the unknown variables are linear. Using the proposed model has allowed to produce records of technological features downlink LTE (partition resource blocks into subsets assigned to the subscriber station RB only one subset), as well as the territorial remoteness of user equipment (the type of modulation and coding). As an example, a solution was obtained in the formulated optimization problem using c system MatLab R2014a. This has been enabled bintprog package optimization Optimization Toolbox. Graphically it shows how dependent bandwidth allocation and resource blocks of the downlink between the user equipment required when changing the value of one of them. The analysis found that the use of the proposed model aims to provide each user equipment the quality of service in terms of bandwidth in the downlink with the possibility of access to additional (non-guaranteed) bandwidth.