The Bell Labs Layered Space-Time(BLAST)communication system has higher spectral efficiencies far beyond those offered by conventional techniques,and is able to increase the channel capacity effectively.In this paper,we investigate the channel capacities of BLAST architecture using the exponential correlation matrix and the uniform correlation matrix model.Numerical simulations are performed with Matlab to verify the proposed formulas. Simulation ressults show that the exponential correlation matrix model predicts better BLAST performance than the uniform correlation matrix model.With small antenna numbers or high signal-to-noise ratio(SNR),these two models approximate perfectly.