دانلود رایگان مقاله واگذاری حامل جزء مشترک و متناوب انتخابی برای LTE-A

Abstract

The bandwidth demand for mobile Internet access is significantly increased with the number of mobile users. Carrier aggregation has been proposed to answer this demand in mobile networks. In carrier aggregation, the best available one or more component carriers of each band are assigned to each user to provide efficient services. Several works have been reported in the literature on mandatory and periodic component carrier assignment methods. Although the former works, especially periodic component carrier assignment methods, have significantly improved the performance of LTE-A systems, many limitations still exist. One limitation of previous works is that data transfer is interrupted during periodic component carrier assignment operations thus, decrease the performance of the system. Therefore, in this paper, selective periodic component carrier assignment technique, which allows continuous data transfer during periodic carrier assignment operations, is proposed and followed by integration of selective technique into four component carrier assignment methods: Least Load, Least Load Rate, Random, and Channel Quality to observe the performance improvements. Results indicate that the proposed selective technique increases the throughput ratio up to 18% and decreases average delay up to 50%. Our analysis and proposed technique will assist service providers to build efficient periodic component carrier assignment methods to improve the performance of the system by reducing delay and increasing throughput ratio.

7. Conclusion and future works

In this paper, selective periodic component carrier assignment technique is proposed by considering the behavior of the system during component carrier assignment operations. The performances of current joint and proposed selective component carrier assignment techniques are compared by using analytic analysis based on queuing theory and an extensive simulation. Both techniques are analyzed according to not only the overall system performance but also the device based performance. Results show that the proposed technique efficiently uses system resources and improves the overall throughput ratio up to 18% and average delay up to 50% in LTE and LTE-A systems. Our proposed technique and related analysis will help service providers build efficient periodic component carrier assignment methods to improve performance metrics such as throughput ratio and delay.