Pseudo‐Noise Code Synchronization of Multicarrier DS‐CDMA Systems on Multipath Fading Channels Part II: Digital Code Tracking with Diversity

Abstract

Abstract.Pseudo-noise code tracking with diversity reception is investigated for multi-camer direct-sequence code division multiple access (DS-CDMA) systems on multipath Rayleigh fading channels. The traditional noncoherent digital delay locked loop (DDLL) is analyzed under the effects of multipath fading and multiple access interference. A new decision-directed tracking loop based on a differentially-detected phase detector is proposed and analyzed. The new tracking loop significantly outperforms the traditional DDLL. Computer simulations have been conducted to verify our analytical results.