3D Pilot Aided Channel Estimation

We address pilot aided channel estimation (PACE) for MIMO-OFDM operating in spatially correlated channels. Pilot symbols are only inserted on selected transmit antennas, and the channel response on the remaining transmit antennas is obtained by means of interpolation. By extending the principle of channel estimation by interpolation to the spatial domain, three dimensional (3D) PACE operates in time, frequency and space. Provided an appropriately dimensioned pilot grid, 3D-PACE is shown to substantially reduce the required pilot overhead without sacrificing channel estimation accuracy.