Modified DFT-based channel estimation for TDS-OFDM communication systems

This paper proposes the modified discrete Fourier transform (DFT)-based channel estimation technique for time domain synchronous orthogonal frequency division multiplexing (TDS-OFDM) communication systems. The proposed technique based on the concept of significant channel tap detector (SCTD) scheme possesses the potentials to effectively improve the system performance of TDS-OFDM systems. The correlation of two successive preambles is employed to estimate the average noise power as the threshold for obtaining the SCTD threshold estimation error and loss path information resulting in performance degradation in large delay spread channel environments. The proposed estimation scheme can also roughly predict the noise power in order to choose the significant channel taps to estimate the channel impulse response. In addition, some comparative simulations are given to show that the proposed DFT-based technique is capable of improving the bit error rate performance compared to the conventional least squares channel estimation.