Complex exponential expansion based blind channel amplitude frequency response estimation for OFDM systems

In this paper, we present a new blind channel amplitude frequency response (APR) estimation method for orthogonal frequency division multiplexing (OFDM). After exploiting the second order instantaneous moment of the received signals in frequency domain, the proposed complex exponential expansion algorithm is introduced to identify the channel amplitude with few parameters. Through the whole algorithm, only a small amount of computation is involved. Therefore, the algorithms can track the channel APR continuously and are amenable to real applications. The algorithm is tested with simulations and also compared with, other method.