基于自适应MIMO-OFDM调制的超宽带通信系统  

UWB communication systems based on adaptive modulated MIMO-OFDM

作　　者：Joseph W.Mwangoka 曹志刚[1] 

机构地区：[1]清华大学电子工程系,北京100084

出　　处：《清华大学学报（自然科学版）》2006年第4期516-518,共3页Journal of Tsinghua University(Science and Technology)

基　　金：国家教育部博士点专项科研基金资助项目(20030003039)

摘　　要：为了避免超宽带信号对现有通信系统的干扰，其发射功率受到严格的限制，这在很大程度上限制了超宽带通信的覆盖范围。该文研究基于自适应多输入多输出正交频分复用的方案，以使超宽带系统在低信噪比要求下能够实现有效通信。该方法充分利用多天线分集和超宽带信道的多径效应。通过自适应调制，在信噪比较好的子载波上传输更多的信息，从而提高了超宽带链路的鲁棒性。在改进的Saleh-Valenzuela信道模型上的仿真结果表明，该系统与传统的正交频分复用相比，在信噪比性能上有8～18dB的提高。Interference of ultra wideband （UWB） emissions to existing services is avoided by strict transmit power limitations imposed upon the UWB emissions which greatly limits the coverage area of UWB communication systems. This paper describes the use of adaptive modulated multi-input multi-output orthogonal frequency division multiplexing （MIMO-OFDM） to enable effective communications in UWB systems with low signal-to-noise （SNR） requirements. The scheme fully utilizes the adaptively modulated MIMO-OFDM benefits from multiple transmit/receive antennas and the multiple paths of the UWB channel. The adaptive modulation opportunistically transmitts more information over subcarriers of the UWB with better SNR. Simulations using modified Saleh-Valenzuela channel model conditions give a performance gain of 8 - 18 dB compared to conventional OFDM systems.

关 键 词：无线通信 超宽带 多输入多输出正交频分复用 自适应调制 Saleh-Valenzuela信道模型 

分 类 号：TN92[电子电信—通信与信息系统]