【作者】 杨杰；

【导师】 谢红；

【作者基本信息】 哈尔滨工程大学 ， 通信与信息系统， 2005， 硕士

【摘要】 第三代移动通信系统采用宽带CDMA技术,其主要目标是实现任何人可以在任何时间、任何地点进行任何方式的通信。然而CDMA移动通信系统的信道为无线信道,它是自然界中的一种较为恶劣的通信介质。在信息的传输过程中,存在着多址干扰、高斯噪声、多径效应、远近效应及多普勒效应等诸多不利因素。这些不利因素极大地影响了CDMA移动通系统的传输可靠性,限制了系统容量。 CDMA移动通信系统作为一种干扰受限系统,任何能提高系统抗干扰性能,即可靠性的技术都能提高系统容量,CDMA系统采用的关键技术都是围绕着在保证可靠性的前提下提高系统容量。在码分多址(CDMA)系统中,功率控制被认为是所有关键技术的核心,可以有效地克服远近效应和多址干扰的影响。本文针对宽带码分多址系统的上行链路提出了一种基于干扰预测的功率控制方法,利用当前时刻和以前若干时刻的干扰对下一时刻的干扰进行最佳预测,以此为基础来解决下一时刻的功率,从而使信干比更接近门限值。并讨论了利用功率控制和多用户检测两者各自的优点而进行联合功率控制的理论和方法,提出了基于多用户检测技术的联合功率控制算法。更多还原

【Abstract】 The third generation mobile telecommunication systemutilizes wide-band CDMA as its multiple access. It aims at that whoever can communicate in whatever way whenever it is and wherever he is. Being wireless channel, the channel of CDMA system is very terrible medial of the nature. In the course of transferring information, there are several disadvantages as time-selective fading, frequency-selective fading, near-far effect, multiple access interference, white Gaussian noise and so on, which affect the reliability of CDMA system and lower the capacity of CDMA system.Because the CDMA system is a interference-limited system, all the technologies that can improve the performance of resisting interference, that’s to say reliability can amplify the its capacity. The key technologies utilized by CDMA system are all aiming at improving the reliability. In this article, a predictive control algorithm for uplink transmission in code division multiple access systems is presented. Using the optimal linear prediction, the interference to the desired user for the future instant is estimated from current and past interference. The result is then used to derive the optimum power levels of the mobile transmitters in the system. Finally the article discusses the theory and method of a novel combined CDMA power control technology that using the advantages of power control and multiuser detection and proposes a combined power control algorithm which based on multiuser detection.更多还原