【作者】 王安义；

【导师】 保铮；

【作者基本信息】 西安电子科技大学 ， 信号与信息处理， 2000， 博士

【摘要】 所谓智能天线系统SAS（Smart Antenna System）就是阵列天线与先进的信号处理技术相结合，形成同时具有空时处理能力的天线，目前该技术已成为国内外非常热门的研究领域。智能天线技术已成为第三代移动通信系统的关键技术之一。在无线移动通信系统中采用智能天线技术，实现最优收发天线波束形成和自适应信号处理，可以为蜂窝系统提供高质量的数据链路，提高基站天线的覆盖范围以及系统容量和业务质量，降低移动用户的码间干扰和多址干扰，以及降低发射功率等。利用阵列天线，能更好地抑制来自邻近或同一小区的共信道用户干扰，抵抗远近效应。因此，本文研究了CDMA移动通信系统空时二维RAKE接收机实现方案及处理算法、相关的多径参数估计、收发天线自适应波束形成以及空时多用户检测技术。全文的主要工作概括如下： 1．基于宽带天线阵，利用CDMA信号的恒模特性以及用户已知的扩频码提出一种盲空时2D RAKE接收机ST-DRCMA处理算法，它避免了每个阵元延时抽头输出进行码滤波，也不需要进行信道参数估计，使CDMA信号的空时处理达到较高的性能。从而有效地消除CDMA系统中的多址干扰MAI和多径传播引起的码片间干扰ICI。 2．在W-CDMA方式下提出了一种新的空时2D RAKE接收机，在第三代移动通信系统中由于增加了上行辅助导频信息，基于W-CDMA系统的上行导频信息进行信道参数估计，并提出了两种级联结构2D RAKE接收机的实现方法，分析了空时2DRAKE接收机的误码性能。 3．在单径情况下，利用最小均方误差（MMSE）和最大似然（ML）准则，推导了线性空时CDMA多用户检测算法，分析了空时多用户检测与单用户检测的关系，并提出一种空时CDMA多用户检测接收机结构及一种自适应的空时多用户检测方法。与单用户检测方法相比其误码率有相当的改进。 4．利用最小均方误差准则（MMSE）和最大似然（ML）准则，推导了异步多径条件下空时CDMA多用户检测算法，分析了空时多用户检测与空时RAKE单用户接收机的关系，并提出了异步多径情况下空时多用户检测接收机结构。同时，并利用CDMA信号的有限字符特性和上行信道已知的导频信息对基于迭代SAGE算法的多用户检测提出改进方法。 5．智能天线与多用户检测相结合，利用逐次干扰抵消多用户检测方法，结合单 西安电子科技大学们土学位论文一用户空时KAKE接收机提出一种空时逐次干扰抵消CDMA多用户检测，并椎导了一种空时逐次于扰抵消CDMA多用户检测算法。通过计算机仿真分析说明了本文提出的空时干扰抵消CDMA多用户信号检测方法的性能，与单用户空时RAKE接收机方法相比其误码率有相当的改进。 6．在CDMA移动辽信系统中，基于上下行信道的双向共性特征，通过基站对上行接收信号子空间分解，确定下行发射信号子空间特征，从而对CDMA移动通信系统提出一种下行最优发射波束形成与上行空时RAKE接收机联合处理技术。与其他相比它不需要估计所有用户的DOA和多径幅度信息。更多还原

【Abstract】 The Smart Antenna System, has been the present focuses in signal processing and communication field, which smart multi-beam antenna is formed by means of antenna array embedded by signal process technology. And The Smart Antenna has also been one of the key technologies of the Third Generation Mobile Communication Systems. Optimum beamforming in receiving and transmitting mode and adaptive signal process can be formed by means of the Smart Antenna Technology in wireless communication, then base antenna coverage, system capacity and service quality are improved, also inter-symbol interfere. multi-access interfere and transmitting power are reduced. In addition, co-channel interferes and Near-far problem is well jammed due to the Smart Antenna. In this dissertation, space- time 2 D RAKE receiver version and algorithm related multi-path parameter estimation, adaptive beamforming in receiving and transmitting mode, and space-time multi-user detection in COMA communication systems are studied. The main contributions of the dissertation are as follows: 1. Based on broadband antenna array, a new blind ST-DRCMA algorithm is presented which combats both MAI and ICI for OS/COMA systems. The algorithm proposed utilize the constant modulus properties of CDAM signals and spread signature known. Also no despreading and channel parameter estimation is needed on the output of delay taps. and computation complexity is low. Computer simulation is illustrated the performance of ST- DRCMA receiver. 2. Space time 20 RAKE receiver is applied in the Third Generation Mobile Communication Systems. In other words, space time 2D RAKE receiver is realized in W- CDMA condition. Due to the aid pilot frequency in reverse link, channel parameter estimation can be implemented in W-CDMA systems. And two kinds of cascade structure 2D RAKE receiver method are presented, also the performance of space time 2D RAKE receiver is analyzed. 3. On single path condition, the multi-user detection algorithm is derived on the basis of?minimal mean square rule and ML rule. The relation of single user detection and multi- user detection is also analyzed. Also a space time multi-user detection structure and an adaptive method on CDMA systems is proposed. The performance of the algorithms proposed is much better than that of traditional single-user detection. 4. Using minimal mean square rule and ML rule on condition of asynchronous multi-path derives CDMA multi-user detection algorithm. The relation of single user detection and space-time multi- user detection is also analyzed. Also a space time multi-user detection structure is proposed. In the meantime, an improvement about the SAGE algorithm is proceeded on the basis of finite alphabet characteristic and pilot information of COMA. 5. Combined with smart antenna, a space-time interference cancellation CDMA multi-user detection is proposed by utilizing successive interference cancellation method. And a new interference successive cancellation algorithm is derived, which combined with space-time RAKE receiver. Computer simulations illustrated that the performance of the algorithms proposed is much better than that of traditional single-user detection. 6. Standing on the fact that bi-directional commonalty holds between up-link and downlink Channel State in COMA mobile communication, downlink signal Sub-space State is defined by up-link signal sub-space decomposition. Then downlink beam-forming weights are generated. This method proposed requires更多还原