WCDMA系统功率控制与发射分集算法FPGA实现研究

【作者】 孟庆峰；

【导师】 林水生；

【作者基本信息】 电子科技大学 ， 电路与系统， 2002， 硕士

【摘要】 本文为WCDMA系统功率控制环路与闭环发射分集算法FPGA实现研究。主要内容包括功率控制算法与闭环发射分集算法的分析与讨论，在分析讨论的基础上进行了FPGA实现方案的设计以及系统的实现。另外在文中还介绍了可编程器件方面的常识、FPGA的设计流程以及同步电路设计方面的有关技术。 WCDMA系统中功率控制部分是系统中较为关键的一部分，决定着整个系统覆盖范围以及系统的容量。功率控制的目标是能够根据移动环境的变化快速调整发射功率的大小，使得既能够保证一定的通信质量又不对其他用户产生太大干扰。功率控制算法实现的好坏对系统性能有着直接的影响。本文在对功率控制算法分析讨论的基础上设计出一种功率控制算法的FPGA实现方案。本方案能够实现协议要求的前向功率控制全部功能，能够满足在不同传输环境下的功率控制要求(包括深衰落环境、慢衰落环境以及软切换时的特殊情况)。实现时，由于前向信道数较多，而功率控制只能是针对每个信道的每个时隙进行控制，考虑到资源的消耗以及全局时序的安排，我们将多个信道的处理打成流水的方式进行，同时对于所有中间结果的存储以及较大时延的调整我们使用RAM来进行。 另外，闭环发射分集也是系统中非常重要的一环，其实现的精度的好坏对于移动台接收效果的改善有着重要的意义。闭环发射分集是根据移动台在上行信道里的反馈的信息对前向主、分集天线上的信号幅度与相位进行调整，使得移动台有最佳的接收效果。为了提高闭环发射分集实现精度以及降低设计的复杂度，实现时我们将相位调整与幅度调整分开进行，相位的调整通过简单的复数乘法即可实现，而幅度的调整我们通过将调整的大小转化为功率地址的偏移，这样在功控后的功率地址上加上一个地址偏置即可实现了幅度的调整，这样一方面避免了复杂的多位数乘法，另一方面使实现精度达到了0.25dB的系统要求。 由于所有设计均是基于FPGA器件以及同步电路设计技术，在本论文中总结了一些可编程器件方面的常识以及FPGA设计的流程，讨论了在实际设计中使用较多的同步电路设计的有关技术。更多还原

【Abstract】 In this dissertation, the realization of algorithm of power control loop and closed transmit diversity with FPGA (Field Programmable Gate Array) has been presented. The algorithm’s analysis and discuss, the function verification and performance test are also been discussed. In addition, the FPGA design flow and the technique of synchronous circuit design have been depicted.The module of power control is a very important part in WCDMA system. It can decide the covering scope and capability of system. The aim of power control is to adjust the transmit power fast according to mobile environment, so it can make the communication quality keep on a certain level and not make too much disturb on other users. In this dissertation, we have designed the module of forward link power control, which can achieve all the function the protocol proposed. According the result of test, the performance of the module can meet the requirement of system guideline. In order to reduce resource consuming and make timing manage well, in module designing, we deal with all the forward channels in pipeline kind.The transmit diversity is also an important part in the WCDMA system. The main aim of this function is to make the receiving effect well without enlarge the total transmit power. In this dissertation, we mainly pay attention to closed transmit diversity. The realizing precision of this algorithm will directly affect the result of receiver. The main theory of closed transmit diversity is to adjust the signal’s phase and amplitude of master and diversity antennas according to the feedback information. In order to make the realization easier and more precision, we use a simple multiplication of complex value to realize the phase adjustment. To amplitude adjustment realization, we use power address offset in the power table. Through the actual test, the module can meet the system requirement.Because all the project is designed at the base of FPGA device and synchronous circuit design technique, some common knowledge about FPGA, FPGA design flow and some key points of synchronous circuit design technique are introduced in this paper.更多还原