低轨卫星网小区移动性对切换的影响

Impact of Cell Mobility on Handovers in Low Earth Orbit Satellite Systems

低轨卫星网络点波束覆盖布局与用户相对运动方向决定了用户在小区间的切换关系,并直接影响用户切换性能。该文针对两种典型的小区运动模式建立了移动模型,分析了驻留时间、切换概率和平均切换次数等移动性指标,并结合具体的信道分配策略分析比较了小区移动性对用户切换性能的影响。结果表明在小区低重叠度的条件下小区运动模式Ⅱ的用户切换性能优于模式Ⅰ,更适用于低轨卫星网络,为低轨卫星点波束的布局提供了参考。

The relative motion direction of spot-beams decides the handover relation between cells for users in Low Earth Orbit （LEO） satellite systems, and directly affects the performance of handovers for users. User mobility models are developed for two typical cell motion patterns, mobility parameters such as cell dwell time, handover probabilities and average number of handover requests are analyzed. The impact of cell mobility on user＇s handovers has been investigated by simulations for a channel allocation technique. It has been shown that modelⅡ has the better performance than modelⅠ, and is more applicable for LEO satellite systems with small cell overlaps, reference can be supplied for spot-beams coverage layout.