ters (e.g. DoA). Therefore a derivable the parameters of the specular components (propagation data model of the antenna array is required. For this paths) as well as the parameters of the distributed diffuse purpose analytic functions of the array manifold are often scatterers. The algorithm is based on the conjugate gra- used in case of design and simulations [KaKC02]. These dient optimisation strategy. In comparison with the approaches often neglect the influence of the antenna SAGE algorithm, the complexity is drastically reduced, beam patterns, mutual coupling and other characteristics especially if the number of paths (components) is small or imperfections of real antenna arrays for simplicity of compared to the number of observations. Additionally, the derivatives. Therefore a derivable data model based on the algorithm provides an estimate of the variance of the calibration measurement data of real antenna arrays is calculated parameters, yielding reliability information of proposed [LaRT04a]. the channel parameters estimated. This tracking algo- The methods using the CRLB to design an antenna rithm has been tested in a static SIMO scenario in an array assume that the estimation algorithm will find the urban environment and described in [AIRT04]. global minimum of the cost function of the optimisation In a MIMO indoor propagation environment, the problem. Most of the estimation algorithms are knowledge of cluster characteristics is very important. sequential; this means that they estimate the channel Here also the SAGE algorithm proves its qualities. First, parameters path by path and parameter by parameter. identification of clusters was done visually using the This can result in a solution which is just a local minimum double-directional angular power spectrum. The charac- of the cost function (e.g. estimation of phantom paths). teristics of each cluster were calculated with the new Therefore also an optimisation of the beamformer is algorithm, based on SAGE estimation of eigenmodes. The considered [TLAP