Experimental Study of Umts Radio Signal Propagation Characteristics by Field Measurement

Knowledge of propagation characteristics in the mobile channel is important to the design, analysis and optimisation of a cellular system. Such need is of great concern to achieve higher quality standards, lower overall running cost, minimize transmit power, better covering of different areas with different environmental situations. Thus, received signal prediction models play an important role in the RF coverage optimization and efficient use of the available resources in wireless communication. As the demand of location based services (LBS) increases in non-line of site (NLOS) environment, a robust received signal prediction model is needed to enhance the accuracy of the LBS techniques. This paper presents a large scale received signal prediction model for various types of propagation environment from field measured signal data. Based on the experimental data obtained, path loss exponent and standard deviation of signal strength variability are determined. It is shown that the values of these parameters vary from study location to location in the coverage area. The results indicate that different empirical models for mean signal strength should be used in different regions of the coverage area for cellular network planning.