Abstract: The combined technology against multiple access interference is a new research field.This article combines smart antenna with the multi-user detection to suppress coherent interference and to improve the bit error rate of the system.In addition,it adopts these key technologies for wireless resource utilization.The paper puts forward a CDMA system model of using multi-user detection after smart antenna,and meanwhile introduces the adaptive filter based on LMS algorithm to eliminate the narrow band interference.At last,it analyzes the nature through Matlab simulation.The results show that the joint anti-interference has better bit error rate performance.

Key words: CDMA system, smart antenna, multi-user detection, LMS algorithm, adaptive filter