Effect of tap gain correlation on capacity of OFDM MIMO systems

The effects of tap gain correlation on the capacity of broadband multiple input, multiple output (MIMO) systems is investigated for orthogonal frequency division multiplexing (OFDM) signalling. A unified broadband MIMO fading channel model is proposed for capacity analysis using correlated tapped delay line fading channels for each antenna pair. It is shown that the amount of tap gain correlation strongly influences the capacity of the broadband MIMO system. When the tap gain correlation is greater than a certain threshold, the capacity advantage of the broadband system vanishes.