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

码分多址（CDMA）通信系统受到多址干扰（MAI）的限制。 多用户检测通过利用所有用户的特征信息来实现多址干扰的消除。 由于最优多用户检测器的复杂性，各种次优检测器结构已被考虑。 在这项研究中，提出了一种称为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，因为它不需要重复的硬件，因为最佳检测器需要。 为了处理相对延迟估计中的误差，利用称为“自举解相关器”的特殊自适应解相关器。 分析了自举解相关器在不同衰落环境和不同时延下的性能，并讨论了其收敛性和稳定性问题。 在实际的通信环境中，还研究了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.