基于空时块编码和正交脉冲的MIMO系统性能研究

摘要

为了有效利用脉冲无线电(IR)的短距离、高数据速率以及多输入多输出(MIMO)通信系统的更大容量,提出了一种基于空时块编码(STBC)和正交脉冲的MIMO超宽带(UWB)通信系统.具体实现是通过对标准单输入单输出(SISO)脉冲无线电系统的直接序列超宽带作为多址(MA)技术的IR-MA信号模型以及信道模型、收发器结构和检测方法的分析,提出了一种把空时块编码和正交脉冲相结合的新方法,并采用FS-rake相干接收(CR)和非相干接收(NCR)技术及IEEE UWB信道模型对其获得的空间分集和编码性能进行了研究,从而得到可以相对较好地描述高信噪比时的性能变化趋势的理论上限值.仿真结果表明,这种STBC-IR方案相比于传统的单链路-脉冲无线电(SL-IR)方案,可获得更好的空间分集和编码增益,可用于增加传输距离和减少rake接收机的复杂性,而且在UWB通信中,STBC-IR方案还能很好地消除定时抖动的影响.%In order to effectively utilize the short distance, high data rate of impulse radios (IR) and the larger capacity of multi-input multi-output (MIMO) communication systems, MIMO ultra wide-band (UWB) communication system based on space time block coding (STBC) and orthogonal impulse was proposed.The specific implementation was made by the analysis of the IR-MA (multiple address) signal model and channel model,transceiver structure and detection methods for a standard single-input single-output (SISO) impulse radio system based on direct sequence UWB as the multiple access technology.A new method was proposed to combine space time block encoding and orthogonal impulse, and the spatial diversity and encoding performance were obtained by using the technology for FS-rake coherent reception (CR) and non-coherent reception (NCR) and the IEEE UWB channel model,then the theoretical upper bounds were obtained to describe the performance trends relatively well at high SNR.The simulation results show that the proposed STBC-IR scheme can obtain the better spatial diversity and encoding gain in comparison with the traditional SL-IR scheme, which can be used to increase the transmission distance and reduce the rake receiver complexity.The STBC-IR scheme can effectively eliminate the timing jitter influence in UWB communications too.