LTE-U与WiFi在非授权频段的共存方案研究

无线数据业务的快速增长给有限的频谱资源带来新的挑战.在当前的各种提高频谱效率方案中,LTE-U(LTE in unlicensed spectrum,LTE-U)通信系统获得了全球运营商的广泛认可.作为5G关键技术之一,LTE-U运用载波聚合技术(carrier aggregation,CA)借助于非授权频段对数据业务进行分流,以达到提高网络数据传输速率、频谱利用率和增强用户移动性的目的.然而,由于LTE-U和WiFi系统接入技术的不同,如何解决两个系统之间的和谐共存成为LTE-U系统能否在非授权频段上使用的关键.对LTE-U的相关背景知识、工作模式、载波聚合技术、LTE-U设计要点进行介绍.指出当前LTE-U和WiFi在共存问题上面临的挑战,并对当前LTE-U和WiFi系统在非授权频段上共存的解决方案进行阐述分析和对比.对未来LTE-U和WiFi系统共存的研究方向进行了展望.

Study on coexistence schemes of LTE-U and WiFi on unlicensed bands

The fast growth of mobile data has brought new challenges on the limited spectrum resource. To address this issues, the LTE-U is adopted as one of the promising solutions by global operators. As being one of the key technologies in Fifth-generation(5G) network, LTE-U could provide a higher transmission rate, spectrum efficiency as well as seamless mobile user experience by taking advantage of the Carrier Aggregation(CA) technology. In particular, the most critical issue of LTE-U is in coexistence with WiFi systems, due to the differences in radio access technology between these two systems. In this paper, we introduce the background and the key technologies of LTE-U, including the operating mode of LTE-U, the CA technology and the requirements in the system design. Furthermore, we point out the primary challenges in the coexistence between LTE-U and WiFi systems, and summarize the proposed coexistence schemes in literature. Finally, we discuss the possible research areas in the future.