Performance Analysis of an MC-CDMA/TDD Uplink System with Pre-Equalizatlon In a Highly Time-Varying Channel

摘要

We deal with channel estimation for an MC-CDMA/TDD uplink system with pre-equalization in a highly time-varying channel. First, the time variation of the channel state information (CSI) during a downlink slot is approximated to a polynomial with a proper order. Then, the CSI during the consecutive uplink slot is estimated by simply extending the polynomial to the uplink slot interval. The time variation of the downlink CSI can be approximated to a 1st, 2nd, or 3rd-order polynomial by using the minimum mean squared error (MMSE) curve fitting method or the Lagrange interpolation method. We use the bit error rate as a proper system performance measure. Through extensive simulations, we conclude that the 2nd-order polynomial approximation scheme based on the MMSE curve fitting works well under various system and channel conditions, and is quite robust to the downlink channel estimation error.