Study of scattering of radiowaves from randomly located vertical wall using compensation theorem approach
A propagation model for microcellular communication is presented based on the compensation theorem. Simple expressions are derived for the field scattered by a plain dielectric wall using the Fresnel approximation with special attention paid to the stationary phase point. This way the same expression can be used for reflection and diffraction calculations. Using a polynomial approximation a simplified expression for the scattered field is derived, which is used to study the scattering of radiowaves from randomly located vertical wall(s). Good agreement is obtained between our theoretical study and experimental data.
Since the introduction of adaptive equalizers in digital communication systems by Lucky [1], much progress has been made. Due to their particular constraints many new and different concepts in the wireless domain have been proposed. The wireless channel is typically time and frequency dispersive, making it difficult to use standard equalizer techniques. Also, due to its time varying nature, long transmission bursts may get corrupted and require a continuous tracking operation. Thus, transmission is often performed in short bursts, allowing only a limited amount of training data. Furthermore, quite recently, advantages of the multiple-input multiple-output character of wireless channels have been recognized. This chapter presents an overview of equalization techniques in use and emphasizes the particularities of wireless applications.