Adaptive Interference Cancellation & Signal Separation in Multi-User CDMA Communication System

码分多址通信系统受到多址干扰（MAI）的限制。多用户检测通过利用对所有用户签名的了解来实现MAI取消。由于最优多用户检测器的复杂性，我们考虑了各种次最优检测器结构。在这项研究中，一种称为DC^3的新结构用于异步用户的自适应多用户检测，它很简单，因为它不需要复制硬件，正如最佳检测器所需要的那样。为了处理相对延迟估计中的错误，使用了一种特殊的自适应去相关器，称为“自举去相关器”。分析了自举解相关器在不同未知时延的衰落环境下的性能，并处理了收敛性和稳定性问题。在实际的通信环境中，研究了DC^3接收机的整体性能。

Code Division Multiple Access (CDMA) communications systems are limited by multiple access interference (MAI). Multiuser detection accomplishes MAI cancellation by exploiting the knowledge of all users' signatures. Due to the complexity of the optimum multiuser detector, various sub-optimum detector structures have been considered. In this study a novel structure termed DC^3 for adaptive multiuser detection of asynchronous users, which is simple in that it does not require duplication of the hardware, as optimum detectors require. To handle errors in relative delay estimation, a special adaptive decorrelator called the 'bootstrap decorrelator' is utilized. Performance of the bootstrap decorrelator under different fading environments with different unknown delays is analyzed and convergence and stability questions are treated. Performance of the DC^3 receiver as a whole is also studied, in a realistic communications environment.