一种适用于多场景的窄带LMS信道模型

廖希, 薛睿, 赵旦峰

(哈尔滨工程大学 信息与通信工程学院, 150001 哈尔滨)



摘要:

针对现存陆地移动卫星(land mobile satellite, LMS)信道模型使用场景有限及状态持续时间概率密度函数(state duration probability density function, SDPDF)不精确问题, 提出能准确有效地描述更多操作场景的窄带LMS信道模型. 利用对数正态分布近似SDPDF的Semi-Markov链实现状态序列. 在每一状态内结合传播参数生成服从Loo分布的载噪比时间序列. 通过在慢衰落成分中引入多普勒频移以增加参数数据库及扩展适用场景. 研究不同场景下状态概率、 载噪比时间序列的一阶统计特性和90％信号有效性所需的余量,并与实测值比较. 研究结果表明: 该模型能在多场景下有效地代表阴影条件, 且在不同信道环境中的各仰角和方位角下具有较好适用性, 可用于系统性能分析.

关键词:  陆地移动卫星  信道模型  Semi-Markov链  基于角度分集的移动卫星信道  Loo分布

DOI：10.11918/j.issn.0367-6234.2015.03.011

分类号:TN927

基金项目:国家自然科学基金 (61371099); 黑龙江省留学归国科学基金 (LC2013C22); 中央高校基本科研业务费专项基金 (HEUCF14080).



A narrowband LMS channel model suitable for more scenarios

LIAO Xi, XUE Rui, ZHAO Danfeng

(College of Information and Communication Engineering, Harbin Engineering University, 150001 Harbin, China)

Abstract:

In view of the problem of limited usage scenarios as well as inaccuracy of state duration probability density function (SDPDF) in existing land mobile satellite (LMS) channel model, we propose a narrowband LMS channel model which is capable of describing much more operational scenarios accurately and effectively. The state sequence is achieved by using Semi-Markov chain which approximates the SDPDF as a lognormal distribution. Within each state the carrier-to-noise ratio (C／N) time series is generated and defined as a Loo distribution by combining with propagation parameters. Doppler frequency shift is applied in slow fading components to increase parameter database and extend usage scenarios. The state probabilities, the first-order statistical characterization of C／N time series, and the required margins of 90％ signal availability are investigated and compared with measurement results under different scenarios conditions. Simulation results show that the proposed model is effective for the representation of shadowing conditions on much more scenarios. In addition, it has a good applicability for different elevations and driving directions in different environments, and can be used in system performance analysis.

Key words:  land mobile satellite  channel model  Semi-Markov chain  mobile satellite channel with angle diversity  Loo distribution