Spatial Clustering Group Based OFDMA Access Protocol for the Next Generation WLAN

下一代WLAN中一种空间聚集群组的OFDMA接入协议

School of Electronics and Information, Northwestern Polytechnical University, Xi’an 710072, China

Received: 10 September 2017

Abstract

The next generation wireless local area network (WLAN) needs to significantly improve the area throughput in high dense scenario. Orthogonal Frequency Division Multiple Access (OFDMA), considered as the key technology of next generation WLAN, has been adopted by next generation WLAN communication standard. However, the existing studies on the OFDMA protocol have the interference extensions problem, i.e. multiple users are located in the dispersive area, and then the geographical interference area is enlarged. In this paper, a spatial clustering group based OFDMA multiple access protocol (SCG-OFDMA) is proposed. SCG-OFDMA enables the users in close area to form spatial clustering groups dynamically, then the users in the spatial clustering group access channel and transmit data by OFDMA. It reduces the geographical interference area, and enhances the area throughput. The theoretical analysis of SCG-OFDMA is also carried out. The simulation results of SCG-OFDMA are in agreement with the theoretical analysis. Simulation results show that the area throughput of SCG-OFDMA is higher than existing OFDMA protocol and distributing coordination function by 15.98% and 31.26% respectively. It provides a reference to design media access control protocol of the next generation WLAN.

摘要

为了提升下一代无线局域网（wireless local area network，WLAN）高密集场景下的区域吞吐量，正交频分多址接入（orthogonal frequency division multiple access，OFDMA）作为关键技术之一已被下一代WLAN通信标准采纳。然而，现有研究所提出的OFDMA多址接入技术均存在传输干扰扩散问题，即多个并行接入的节点位于位置分散的区域，从而对周边的传输干扰面积加大。提出一种空间聚集群组的OFDMA多址接入协议，空间位置接近的节点构成空间聚集群组，该协议使得空间聚集群组内的节点采用OFDMA的方式并行接入和传输，从而降低多个节点同时传输时的干扰范围，进而提升区域吞吐量。此外，根据网络仿真软件得出的结果，进行理论推导，理论分析与仿真结果相吻合。仿真结果表明，当小区节点数为100时，所提出协议的区域吞吐量比已有OFDMA协议和分布式协调功能协议分别提升15.98%和31.26%。为设计下一代WLAN媒体接入控制协议提供参考。