基于时延差异性约束的LTE-R系统频谱需求预测

为了科学地规划和分配LTE-R的用频，需要对其频谱需求总量做出合理预测。在深入分析ITU-R M.1768方法的基础上，提出了一种基于时延差异性约束的LTE-R系统频谱需求预测方法。该方法定义了9种服务类别和9种服务环境，推导给出了LTE-R系统业务量的计算表达式，在业务时延差异性约束条件下利用M/G/1排队模型对我国LTE-R系统的频谱需求进行了初步预测。研究结果表明，我国LTE-R系统上行和下行频谱需求不对称，且可能的范围分别是14~15MHz和5~6MHz，若不考虑未来新增的视频业务量，目前分配给GSM-R系统的频谱资源即可满足其带宽需求。此外，分析了LTE-R网络实际承载层面的工程频率效率和基于高带宽的视频业务量对LTE-R频谱带宽需求总量的影响。该研究为我国下一代铁路移动通信系统的频率规划提供了技术支撑。

Spectrum demand prediction of LTE-R system based on delay difference constraint

In order to plan and allocate the spectrum resources of LTE-R scientifically,it is necessary to make reasonable forecast of total spectrum demand for LTE-R.After deep analysis of ITU-R M.1768 method,a spectrum demand forecasting method based on different delay constraints for LTE-R system was provided.This method defined nine kinds of service categories,nine kinds of service environments,and derived the expression of LTE-R system traffic.Under different delay constraints condition of different services,the M/G/1 queuing model was used to analyze the spectrum requirements of LTE-R system preliminarily.The results show that the uplink and downlink spectrum demand of China's LTE-R system is asymmetric and the possible range is 14～15 MHz uplink and 5～6 MHz downlink,respectively.If new video traffic in the future is not considered,the current spectrum resources distributed to GSM-R system spectrum can meet the bandwidth requirements of LTE-R system.In addition,the influence of engineering frequency efficiency of LTE-R network and high-bandwidth video traffic on LTE-R spectrum total bandwidth demand was analyzed.This study provides technical support for the frequency planning of China's next generation railway mobile communication system.