The performance of the multiantenna systems can be deeply affected by the antenna layout, that is, the placement of the antenna elements in a given area. This paper focuses on the optimal antenna layout which can maximize the ergodic capacity of a multiinput single-output (MISO) beamforming system. Since the optimization problem cannot be solved analytically, we use simulated annealing (SA) algorithm to search for the optimal antenna layout. The results show that the optimal antenna layout

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... ds highly on the power azimuth spectrum (PAS) distribution and power elevation spectrum (PES) distribution. In the three-dimensional (3D) space uniformly scattering environment, the optimal antenna layout will locate the antenna elements on the surface of a sphere. When the scattering is concentrated in a two-dimensional (2D) plane, the circular layout is the optimal and finally, when there is no scattering (single plane wave), the optimal layout is the nonuniform linear array.