System Level Modeling and Optimization of the LTE Downlink

4. Extensions to the L2S ModelIn the next scenario, a simple hexagonal deployment of eNodeBs with omnidirectionalantennas has been employed. Although not representing a more complextri-sector cell layout such as in [69], it still validates whether the SINR model iscapable of predicting the average achievable capacity in an interference-limited scenario.The simulation parameters used in this simulation set are listed in Table 4.4.As SINR averaging is handled by the link performance model, simulation results fora single-carrier setup are sufficient and reduce simulation time.Figure 4.9 depicts for the simulated area the wideband, denoted as SINR Γ(x, y),and resulting from the simulation parameters listed in Table 4.4. For each point(x, y) of the ROI, the wideband SINR corresponding to the closest cell SINR-wise,denoted as the i-th cell, is depicted.y pos [m]500400363002001000 257−100−200−300−40014−500−600 −400 −200 0 200 400 600x pos [m]4035302520151050Considered simulation area: center cellFigure 4.9: Network layout used for the multi-cell simulation. The center highlighted areashows the points taken into account for the simulation.Figure 4.10 show the results of the accuracy of the model for the 2×2 and 4×4antenna configuration cases, respectively.F(x)10.90.80.70.60.50.40.30.20.11 layer2 layers00 5 10 15Achievable capacity [bit/s/cu]F(x)10.90.80.70.60.50.40.30.21 layer2 layers0.13 layers4 layers00 5 10 15 20Achievable capacity [bit/s/cu]Figure 4.10: Achievable capacity results for the 2 × 2 (left) and 4 × 4 (right) antenna configurations.Solid line: modeled achievable capacity. Dashed line: calculatedachievable capacity.62