Wireless channel characterization and modeling

The analysis of measurements conducted in indoor wireless channels and free space optical channels are addressed in this thesis. A parametric model for representing the indoor channel impulse response is investigated. In the experimental component TCP throughputs and received signal level variations in an indoor wireless channel are measured and analyzed. The throughput degradation is attributed to the influence of the link and transport layer protocols in presence of channel interference. Experimental measurement of received intensities from a 28 km free space optical link are statistically characterized and a probability density function is hypothesized. The average bit error rate from the proposed distribution and that exhibited by the measurements are in good agreement over an intensity range of 0 to 1.5 V.; The impulse response of an indoor channel is represented as a parametric model by means of a transfer function model. The coefficients of the transfer function are solved using Steiglitz-McBride algorithm and simultaneously minimizing the error between the system and model responses. The response obtained by this method are in good agreement for the narrowband frequencies. Poles and zeros estimated from this model verifies the impulse response behavior.