Title :
Discrete tracking and its performance in CTDMA systems
Author :
Li, Yan ; Zhu, Shihua ; Cai, Jun
Author_Institution :
Xi´´an Jiaotong Univ., China
Abstract :
In code time division multiple access (CTDMA) systems, the tracking loop does not work continuously due to the time division feature of the scheme. This paper investigates the impacts of the mobile user movement, clock instability and signal frame duration on the performance of the tracking loop in a CTDMA system. The study shows that the mobile speed has little effect on tracking, but the clock drift may cause desynchronization when the chip rate is high. The tracking error is shown to be proportional to the frame duration, and the SNR degradation of the demodulated signal to be equal to the ratio of the tracking error to chip duration
Keywords :
clocks; code division multiple access; land mobile radio; radio tracking; stability; synchronisation; time division multiple access; CTDMA systems; SNR degradation; clock drift; clock instability; code time division multiple access; demodulated signal; desynchronization; discrete tracking; frame duration; high chip rate; mobile user movement; signal frame duration; tracking error to chip duration ratio; tracking loop performance; Circuits; Clocks; Delay estimation; Frequency conversion; Frequency synchronization; Multiaccess communication; Propagation delay; Spread spectrum communication; Time division multiple access; Tracking loops;
Conference_Titel :
Communication Technology Proceedings, 1998. ICCT '98. 1998 International Conference on
Conference_Location :
Beijing
Print_ISBN :
7-80090-827-5
DOI :
10.1109/ICCT.1998.743399
