Modelling and performance prediction for multiple antenna systems using enhanced ray tracing

Multiple antenna systems can enhance wireless communication links by improving their capacity and/or reliability. Multiple Input Multiple Output (MIMO) communications are the most common exploitation of this property. When applied to deterministic ray modelling, the computational cost of MIMO predication is a major drawback. In this paper, two MIMO modelling approaches are investigated. Both methods make use of an enhanced deterministic ray-tracing propagation model. The first method relies on point-to-point prediction for each of the multiple element to element links. The second approach estimates the MIMO link matrix from a single point-to-point ray tracing study. A comparison of normalized capacity and path loss is performed for the two methods in an outdoor city centre environment. For a Single Input Multiple Output (SIMO) case, the two modelling approaches are presented and compared with measured array data. Result show that the single point-to-point approximation works well and can significantly reduce run-time when compared with full element to element ray tracing.