| Summary: | 碩士 === 國立臺灣大學 === 電信工程學研究所 === 95 === This thesis consists of two parts. The first part concerns the study of transmission effects of indoor wireless communication under different frequency bands for Saleh-Valenzuela model which includes 2.4 GHz and 60 GHz. We will understand indoor channel characteristics by means of channel parameter set {beta0,γ,lamda} for Saleh-Valenzuela model, in which beta0 represents the amplitude difference of the direct path and the start point of the linear regression line of power delay profile, γ represents the slope of the linear regression line, and lamda represents the mean ray arrival rate. We use this model to extract channel parameters which allows us to observe characteristics of all channels such as 60 GHz system in LOS environment and 2.4 GHz system in LOS environment. In addition, we made a study of the effects of field pattern of antennas and human blockage under WLAN for 60 GHz system. In LOS environment, the performance of the received signal at the receiver of directional antenna is better than omni-directional antenna. In spite of human blockage between the transmitter and the receiver, however, the average received power of directional antenna at the receiver is still better than omni-directional antenna.
The second part of this thesis involves the measurement of a MIMO system with different antenna polarizations in 2.4 GHz frequency band in indoor environment. In LOS environment, applying co-polarization antenna scheme symmetrically on both ends demonstrates a good received power, but the channel capacity will be poor. On the contrary; using orthogonal polarization antenna scheme on both ends will result in high power isolation at receiver, and the channel capacity will be better.
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