This paper investigates the impact of channel estimation errors in the uplink and downlink of a multicarrier code-division multiple-access system. Pilot blocks are periodically inserted into the downlink data stream to perform a least-squares channel estimation. It is shown that a single-user minimum-mean-square-error (MMSE) detector endowed with the proposed channel estimator has relatively lo...

In this paper, an observer design is proposed for linear time delay systems. An easy way to compute least square estimation error of an observer for time delay systems is derived, where the time delay terms exist in the state and output of the system. Based on the least square estimation error an optimization algorithm to compute a Kalman filter for time delay systems is proposed. By employing ...