Low complexity multipath elimination technology in a spread spectrum system

This paper discusses means to eliminate multipath effects in spread spectrum systems. To this end the current multipath estimation delay locked loop (MEDLL) was investigated and improvements were proposed based on the zero-point fixed principle. A structural chart of the pseudo noise (PN) code tracking loop was developed, and a mathematical model of the signal tracking system in a multipath environment was presented. While considering only one duplicate path, we analyzed the influence of it on the loop's discriminative ability. A MEDLL was introduced in this paper. In order to keep the loop stabilization zero point invariable we introduced zero-point fixed MEDLL (ZFMEDLL), and compared the ZFMEDLL relatively with common DLL, narrow DLL and MEDLL in aspects of stable phase error performance, noise performance and structural complexity of ZFMEDLL. The results indicated that ZFMEDLL, compared to MEDLL, significantly improves ability to resist multipath effects.