A Noise-resilient Channel Estimation Algorithm Based on Two-Dimensional Hadamard Transform for OFDM Systems

Cyclically extended guard interval in OFDM systems turns the traditional time-domain equalization into simple frequency-domain equalization, but channel noise deteriorates the accuracy of channel estimation, thus degrading the performance of equalization. By incorporating with two-dimensional Hadamard Transform, a noise-resilient channel estimation algorithm is proposed. Energy of the channel is concentrated with two-dimensional Hadamard Transform, and noise is reduced in the transform domain. It can be proved with simulation that performance of the proposed algorithm is better than that with MMSE estimation based on Fourier Transform, and even close to that with perfect channel estimation. Moreover, the computation required is pretty smaller due to the use of Hadamard Transform.