Channel capacity of MIMO architecture using the exponential correlation matrix

Multiple-input multiple output (MIMO) communication architecture has recent ly emerged as a new paradigm for wireless communications in rich multipath environment, which has spectral efficiencies far beyond those offered by co nventional techniques. Channel capacity of the MIMO architecture in indepen dent Rayleigh channels scales linearly as the number of antennas. However, the correlation of a real-world wireless channel may result in a substantia l degradation of the MIMO architecture performance. In this letter, we inve stigate the MIMO channel capacity in correlated channels using the exponent ial correlation matrix model. We prove that, for this model, increase in co rrelation is equivalent to decrease in signal-to-noise ratio (SNR). For exa mple, r = 0.7 is the same as 3-dB decrease in SNR.