4.2 Performance of integrated antenna array

We consider the four-port integrated antenna, which was proposed in Section 3 as the array element of the integrated antenna array. We assume that all antenna arrays have Nt ¼ 16 antenna elements and that the receive system has ideal channel condition which means R<sup>H</sup><sup>r</sup> ¼ INr . We verify the performance of the integrated antenna array compared to two reference arrays as shown in Figure 11. The reference arrays are mono-polarization (MPOL) and dual-polarization (DPOL) antenna arrays. The MPOL and DPOL antenna arrays have array elements which are composed of mono-polarization dipole and dual-polarization dipoles, respectively. Then, MPOL, DPOL and integrated antenna arrays have Bt ¼ 1, 2 and 4 and Lt ¼ 16, 8 and 4, respectively. Here, we consider a channel model describing an urban macro-cell environment [20].

The channel capacities of the integrated MPOL and DPOL antenna arrays are illustrated in Figure 12. Although the integrated antenna array occupies smaller size than the others, the integrated antenna array has higher channel capacity than the MPOL and DPOL antenna arrays. It means that the multiple radiation patterns of various antenna elements for the integrated antenna may enhance the channel capacity without increasing antenna space to utilize spatial gain.
