Improved joint pilot allocation and channel estimation algorithm for OFDM system

A novel pilot insertion and channel estimation algorithm for orthogonal frequency division multiplexing (OFDM) systems over slow fading channels is presented. The pilots overhead in the proposed insertion technique is reduced to 12.5% as compared to conventional block type channel estimation. The proposed channel estimation algorithm is aimed at reducing the channel noise, which is inherent in the least square (LS) estimation. The proposed channel estimation algorithm uses LS for channel impulse response estimation at pilot subcarriers. The channel frequency response at all of the subcarriers for the entire block is estimated by using the inverse fast Fourier transform (IFFT), zero padding, and the fast Fourier transform (FFT). The performance (in terms of the bit error rate) of the proposed channel estimation algorithm and the pilot arrangement is compared with the LS estimation for block-type pilot arrangement. Simulation results show that the proposed channel estimation algorithm outperforms the block-type pilot arrangement with LS estimation.