Low Complexity Multiuser Detection Algorithms Study

Multiuser detector (MUD) makes full use of the information of all the users that cause multiple access interference (MAI) to detect the desired user. Therefore, as compared with the conventional detector, it has better resistance capability to the MAI and the so-called near-far problem. Since the multi-user detector reduces the precision requirement of the power control, it can provide higher efficiency for frequency use, and thus improves the capacity of the communication system. In addition, the multi-user detector can be used in conjunction with the smart antenna and power control techniques, hence it may reduce the cost while improving highly the capacity of the system. Unfortunately, due to heavy computational complexity, the existing algorithms limit the application of the multi-user detector, and how to improve them becomes an important task in the third generation of mobile communication systems.This paper surveys the development of the multi-user detector as well as new techniques used in this field. After two kinds of typical and basic algorithms, we introduce the performance index to measure the multi-user detector and the principle used to choose the MUD algorithm. Finally, two upswing algorithms are given, one reduces the computational complexity and improves the resistance capability to the near-far problem, and the other is an adaptive blind MUD algorithm with a simple structure.