摘要
为降低高空平台CDMA(HAPS-CDMA)系统干扰并提升容量,针对CDMA系统上行链路容量受干扰所限的特点,提出了一种新的双层蜂窝重叠覆盖方案。该方案在原有HAPS-CDMA系统热点小区上引入单个地面CDMA基站服务小区,形成双层蜂窝重叠覆盖系统,并通过调整引入的地面CDMA小区大小来达到最大可能减小HAPS-CDMA系统小区内干扰、提高系统容量的目的。为了更贴近实际,假设地面用户呈高斯分布。仿真结果表明,与单系统相比,该双层蜂窝系统能够较好地降低小区内的干扰,改善各层小区系统容量,尤其是热点地区容量提升最大,且在双蜂窝半径比达到特定值时各层小区均获得最佳容量改善量。
Because the uplink capacity of a cellular code division multiple access ( CDMA) system is limited by in-terference, a novel coverage configuration of overlapped two-layer cells was proposed to reduce the interference and enhance the uplink capacity of a high altitude platform station CDMA( HAPS-CDMA) system. In the proposal, one terrestrial CDMA cell was inset to a HAPS-CDMA cell, the maximal possibility was obtained by modulating the size of the terrestrial CDMA cell to reduce the same-cell interference and enhance the system capacity. According to practical situation, users on the ground distribute in Gaussians. Simulation results show that the proposal can reduce the same-cell interference and enhance the system capacity, especially in the hotspot district. When the radius ratio of two different cells is in a particular value, each layer of the cells' capacity will gain the great improvement, compared with either a ground-based CDMA system or a HAPS-CDMA system.
出处
《解放军理工大学学报(自然科学版)》
EI
北大核心
2014年第6期514-518,共5页
Journal of PLA University of Science and Technology(Natural Science Edition)