摘要
LTE系统在下行采用了OFDM技术。OFDM技术将高速数据流调制到相互正交的N路子载波上,因此易受频偏的影响,尤其在多普勒频偏较大的高速环境下会受到严重的干扰。本文依托LTE系统,提出一种针对高速铁路场景的信道估计方法,在基于最小二乘(least squares,LS)估计的基础上,针对高速移动环境提出相应的处理方法,包括基于循环前缀(cyclic prefix,CP)的频偏估计和时域能量集中等处理,仿真分析结果表明,与传统方法相比更适合高速场景,在车速达到500 km/h时仍然保持良好的误码率,具有一定的实用价值。
In the downlink transmission,LTE（long term evolution） system adopts OFDM technology,which modulates the high-speed data streams to N way orthogonal carriers.As a result,it is so vulnerable to the impact of frequency offset,especially in the Doppler frequency shift of high-speed environment,there will be a serious interference.In this paper,a special channel estimation process in LTE system is proposed for high-way environment.It is based on LS estimation,employing the methods of the CP-based frequency offset estimation and time domain energy concentration and other treatment to meet the high-speed mobile environment.Simulation results show that this method is more suitable for high-speed scenario compared with traditional methods,and as the speed reached 500 km/h,the error rate is still well-behaved.
出处
《电信科学》
北大核心
2011年第11期90-94,共5页
Telecommunications Science
基金
国家自然科学基金重点资助项目(No.61032002)
中央高校基本科研业务费专项资助项目(No.2009JBZ003)
北京交通大学基本科研业务费资助项目(No.2011YJS019)
关键词
LTE
信道估计
高速铁路
多普勒频偏
降采样
LTE
channel estimation
high-speed railway
Doppler spread
down-sampled
