Statistical properties of the MUSIC synchronization method for DS-CDMA systems

An analytical expression for the variance of the MUSIC propagation delay estimator for direct-sequence code-division multiple access (DS-CDMA) communication systems is derived. A convenient expression, valid for large signal-to-noise ratios, is also found. The results are asymptotic in the sense that the estimator is allowed to observe the received signal for an extended period of time; however, simulations show good agreement between the asymptotic results and the measured variance for reasonably short data blocks. It is shown that the asymptotic variance is invariant to the interfering users´ powers, hence the MUSIC estimator is near-far robust