Improved Channel Estimation Method Based on Time-Domain Processing for OFDM Systems

Channel impulse response (CIR) can be estimated by time-domain processing (TDP) based on cyclic correlation in orthogonal frequency division multiplexing (OFDM) systems. We propose an improved generalized TDP method to reduce the estimation error by taking the average of different CIR values which are derived according to the different starting points of cyclic correlation. Moreover, an effective channel length estimation method which is performed by reverse detection processing to search the last effective CIR is also proposed. The whole proposed method is more efficient to OFDM systems with long cyclic prefix (CP) because the CP information is sufficiently utilized during the CIR estimation. The analysis and the simulation results verify that the mean square error (MSE) performance of the proposed method is 4-5 dB better than the conventional method under the same conditions.