LMSE-Based Parameter Acquisition for Multicarrier CDMA Systems

A least mean-squared error (LMSE) based scheme for acquiring the symbol timing, carrier phases, and resolvable path gains is proposed for multicarrier code-division multiple-access (MC-CDMA) systems. A new coefficient called the quasi-mean-squared accuracy coefficient (QM-SAC) is introduced. This allows the joint search for multiple optimal parameters to be split into a series of simple one-dimensional estimates, and thus leads to a computationally simple acquisition algorithm. The spreading sequence of the desired user is the only prior knowledge required for the proposed approach. Simulation results demonstrate the near-far resistance of the approach and show that the minimum mean-squared error (MMSE) detection with acquired parameters offers a better error performance that a RAKE receiver does with exact parameters.