High accuracy and low complexity timing offset estimation for MIMO-OFDM receivers

This paper presents a high accuracy and low complexity timing offset estimation algorithm for Multi Input Multi Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) receivers in the tracking mode. First of all we propose an effective architecture of phase tracking for MIMO-OFDM receivers. Then we describe two timing offset estimation algorithms; pilot-aided and CFO-aided timing offset estimation. The first algorithm is a timing phase estimation that can minimize the effect of distorted scattered pilots due to severe fading. We show that the performance of the proposed pilot-aided timing offset estimation very close to that of an offset-free system. The second algorithm attempts to use the computation result of carrier frequency offset estimation in order to reduce complexity. The proposed CFO-aided timing offset estimation has very low complexity comparable to that of the pilot subcarrier aided schemes without performance degradation.