摘要
针对高速空地数据传输时由于地面反射产生信号衰落、引起码间干扰的问题,阐述了空地数据传输的二径模型、信号衰落的模式及特点;在此基础上,对QPSK、QAM和OVTDM 3种调制体制进行了分析;使用MATLAB对3种调制方式在二径模型下信号的码间干扰进行了仿真、比较,并给出了一种2符号OVTDM的信号波形。仿真及分析结果表明,2符号OVTDM的码间干扰和波形畸变小,频谱利用率高,性能优于QPSK和16QAM。
High speed air-ground data link is often disturbed by inter symbol interference （IS1） and signal attenuation by ground reflection. This paper expatiates the modes and features of the two-path model and signal attenuation in air-ground data link, analyzes the mechanism of QPSK,QAM and OVTDM. The MATLAB-based simulation and comparison was performed for the inter symbol interfer- ence effect among the three modulation approaches,and presents a dual-sign OVTDM waveform. Simulation and analysis results shows that dual-sign OVTDM presents small inter symbol interference and waveform distortion,as well as better spectrum use,which provides higher performance over QPSK and 16QAM.
出处
《无线电通信技术》
2013年第2期43-46,共4页
Radio Communications Technology
