A Performance Bound for Interpolation of MIMO-OFDM Channels

The performance of MIMO-OFDM communication systems depends upon accurate channel estimation across frequency bands much wider than the coherence bandwidth of the channel. Obtaining channel estimates at all necessary frequencies typically involves interpolation of channel estimates obtained using pilots at a few distinct frequencies. This paper derives a performance bound for channel estimates obtained via frequency interpolation for slowly-fading frequency-selective channels. Numerical simulations of the bound indicate that normalized interpolation performance improves significantly as the number of antennas increases, suggesting that fewer pilots are needed as antennas are added to a MIMO-OFDM system.