Height pattern evaluation for coverage area designing on upper floors of multi-story buildings

People use wireless communication systems regardless of the location, outdoor or indoor. It is important to predict the coverage area of wireless communication systems in all places. The goal of this study is the accurate estimation of coverage area in buildings including multi-story buildings. If the received power at the outside buildings of each floor is estimated correctly, the coverage area in indoor buildings for wireless communication can be predicted by higher accuracy. Therefore, the height pattern that shows the characteristic of received power above ground considering surrounding buildings is necessary. To design the novel height pattern model, this paper investigates the characteristics of the received power corresponding to the variation in receiver height near the building. As an approach to analyzing the effect of the varying receiver height and buildings, this paper compared simulated and measured values to traditional propagation loss models. A ray-tracing simulation and measurement in an actual environment were also performed. As a result, the received power near the building was observed to be close to that of the Walfisch-Ikegami model at a lower height than that of the surrounding buildings. In contrast, when the receiver height exceeded that of the surrounding buildings, the characteristic of the received power resembled that of the ground-reflection model by two rays. In addition, the level of average received power was close to that in the free space propagation loss. However, Authors found that there was greater standard deviation of the received power near the building than far away. Moreover, the received power of the measurement is lower than that of the ray-tracing simulation, making it difficult to estimate the received power at each height with the traditional model. To design the novel height pattern, the receiver height and its distance from the closest building must therefore be considered.