No abstract

This paper presents a review of rain attenuation studies based on measurements performed since 1987 in tropical and equatorial regions of Brazil. The terrestrial measurements include long term measurements for frequencies between 11 and 38 GHz at 20 links. The satellite measurements have been performed in the Ku band using radiometers and beacon receivers at 10 sites.

This paper presents the preliminary results of channel characterization in the 700 MHz band, based on measurements of an OFDM modulated signal in urban and rural environments. This band will be used for mobile wideband communications in Brazil. An investigation of the dispersion parameters of the channel was carried out in the two different environments aiming a comparison between results of mean excess delay and RMS delay spread, useful for systems design.

This paper presents preliminary results of field measurements carried out for evaluating the operation of the ISDB-TB standard digital TV in the VHF-high band. Measurements were performed in urban, suburban and rural areas in a medium-sized Brazilian city. The analysis includes results of static reception measurements for evaluating the received field strength and the signal to noise ratio thresholds for correct signal decoding. A comparison with theoretical values of field strength is also presented.

No abstract