An estimation method for fine-time synchronization of FH systemsusing the early-late filter technique

摘要

A novel method for estimating the fine-time error in a FHSSn(frequency-hopped spread spectrum) FDMA satellite system system has beennderived. This method, based on the early-late filter technique, usesnthree second order moments to provide a low-biased, but consistent,nestimate of the time error. Results from an approximate analysis andnfrom simulation show the good performance of the estimator. Thenestimator was found to be extremely robust in Rayleigh fading. Innpartial-band noise jamming, the estimator is consistent, although anlarger value of L (hop periods) is needed to give performancenequal to that for the unjammed case. For partial-band tone jamming, thenestimator is inconsistent, although its standard deviation equals thatnfor the unjammed case