摘要
1xEV-DO是CDMA2000针对数据业务的增强系统。为提高数据传输速率,1xEVDO前向链路引入了8PSK和16QAM这样的高阶调制以及Turbo码。本文在简要介绍CDMA20001xEV-DO系统前向链路的基础上,着重研究了相应的调制与编码技术。文中以16QAM为例推导了MAP,Log-MAP及Max-Log-MAP软解调算法,另外还说明了Turbo解码器如何针对软信息输入做必要的修改,最后通过在不同信道下1xEV-DO系统前向链路仿真分析了解调和解码算法的性能。
lxEv -DO is the data -enhanced system of CDMA2000. In order to increase the data transmission rate, multilevel modulation techniques ,such as 8PSK and 16QAM ,and Turbo code are used in this system. Based on a brief introduction to the forward link of lxEV -DO system. In this paper,the corresponding modulation and coding techniques are studied. The MAP,Log-MAP and Max -Log- MAP demodulation algorithm of 16QAM as an example are presented,and a necessary modification of Turbo decoder needed to adapt to the input soft information is also presented in this paper. Then the performance of demodulation and decoding algorithms is examined by the simulation of the forward link of lxEV -DO system on different kinds of channels.
出处
《现代电子技术》
2005年第23期23-25,31,共4页
Modern Electronics Technique
