Abstract:

For the system of multiple input multiple outputorthogonal frequency division multiplexing (MIMO-OFDM), the channel estimation algorithm using discrete Fourier transform (DFT) can be used to improve precision of the least squares (LS) algorithm. However, the DFT based estimation algorithm makes no disposition about the noise existing inside the maximum delay. Therefore, the accuracy of this algorithm is also easily affected by noise. Aiming at this shortage, an improved channel estimation algorithm based on cyclic prefix (CP) is proposed. Regarding the length of CP as criterion, the improved algorithm replaces the channel coefficients over CP with zero. Meanwhile, it replaces the channel coefficients inside the length of CP with zero when their module values are smaller than the setting threshold value. Theoretical and experiment results prove that the 〖JP2〗proposed improved algorithm restrains noise effectively and brings some improvement of estimation accuracy.