Optimisation of radio coverage in urban microcells using a UTD based ray-tracing model

In cellular communications, requirements for increased system capacity, improved coverage, better quality and reduced transmitter power, along with the need to rationalise cellular system planning, have prompted a considerable interest in the development of valid and efficient radiowave propagation models. This work utilises recent advances that improve the accuracy and efficiency of ray-tracing models, using a three-dimensional representation of the terrain and urban topographies, in conjunction with adaptive and selective ray-tracing. These improvements allow utilisation of the field computation algorithms in the network design and radio coverage planning processes. They include optimum automated selection of base station locations and phased array excitation. A reliable ray-tracing scheme can be utilised directly in the optimum and, potentially, adaptive beamforming of base station antenna systems by interfacing field computations with design aims. The paper addresses a cellular planning process, which involves determination of the antenna array position and beam shape or, equivalently, the array excitation coefficients, for a desired power distribution over the defined cell area.