Pseudo‐Noise Code Synchronization of Multicarrier DS‐CDMA Systems on Multipath Fading Channels Part II: Digital Code Tracking with Diversity
Wern‐Ho Sheen, Ming‐Jou Chang, Cheng-Shong Wu · European Transactions on Telecommunications · 1999
Abstract Pseudo‐noise code tracking with diversity reception is investigated for multi‐carrier 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.