Iterative sparse channel estimation for acoustic OFDM systems

We propose a method for channel estimation in orthogonal frequency division multiplexing (OFDM) systems with an array of receiving elements. In contrast to traditional methods, which target the equivalent sample-spaced channel taps, this method targets the physical propagation paths whose delays are not restricted to the sample-spaced grid. The path delays are estimated jointly with the path gains and the angles of arrival, exploiting coherence between the array elements. Numerical results illustrate superior performance as compared to tap-based channel estimation, as well as additional gain available from spatial correlation across the array elements.