车载自组网络—VANET(Vehicle Ad Hoc Network)作为移动自组网和传感器网络在道路交通领域的应用,节点具有对等性、高速移动等特点,这导致了VANET无线信道与无线蜂窝网络信道有着显著区别。文中主要研究开阔区域中车辆间通信的无线信道模型:在三维多径散射场景下,考虑配备定向天线的车辆终端,推导VANET双移动通信节点之间无线衰落信道的自相关函数与多普勒功率谱密度函数的解析表达式。该结果对于VANET网络下无线多媒体业务性能评估有着重要的作用。
In this paper,we propose an improved structure for M-dimension ( M ≥ 2)turbo codes using M identical component encoders. The presented structure only applies single recursive convolutional encoder to encode M interleaved versions of infor-mation sequence and single tail sequence to operate termination. For the commonly used two-dimension (M = 2) turbo codes,two cascade soft input soft output (SISO) decoders are detailed to de-code the corresponding codes. With the two cascade SISO decod-ers,this coding structure obviously outperforms traditional turbo codes at high code rates,especially,about 0.3 dB gain can be ob-tained at code rate 0.9 in additive white Gaussian noise channel with quadrature phase shift keying modulation. This makes the proposed coding structure very attractive for future radio commu-nication systems with high throughput requirements.
WANG Zhenghai1, TIAN Mao1, WANG Yuhao2 1. School of Electronic Information, Wuhan University, Wuhan 430072, Hubei, China
