In one example, a base station system comprises a base station radio unit for at least a first operating frequency and a plurality of linear antenna arrays. Each linear antenna array may comprise a plurality of radiating antenna elements, and the plurality of linear antenna arrays may be disposed in a horizontal plane. In one example, at least one set of linear antenna arrays of the plurality of linear antenna arrays for a first operating frequency has an array separation distance of substantially 1.6+1.1n wavelengths apart for the first operating frequency, where n is an integer greater than or equal to zero. In addition, in one example, the plurality of linear antenna arrays includes at least one linear antenna array for a second operating frequency that is different from the first operating frequency.