Integration of High Speed Train Channel Measurements in System Level Simulations

The trade-off when simulating wireless cellular networks is mainly between accuracy on the one side and simulation time and supported maximum network size on the other side. A common approach in system level (SL) simulations is to utilize various abstractions that also include employing propagation models, which can be parameterized by only a small number of values. When investigating high speed train (HST) scenarios, the distinct effects of this particular environment have to be reflected in the chosen models. In order to verify the validity of SL simulations in this context, we incorporate the results of channel measurements, obtained in a real-world train transmission scenario, in our SL simulations and compare the obtained results to those of post-processed results obtained directly through the measurement data. We show that despite of the various abstraction steps in SL simulations, average throughput results are in good accordance and general trends are preserved. Additionally, we take advantage of the more flexible SL simulations and investigate the influence of feedback delay and jitter. In a last step, we then discuss the advantages of introducing a channel quality indicator (CQI) feedback backoff, in order to improve the reliability of the connection in this context.