Abstract:
The wide bandwidth of millimetre wave allows for its usage in uncompressed video
broadcasting. However, frequencies above 10 GHz tend to suffer a high attenuation with
rain, the prevalent of high intensity of rain in the tropics makes millimetre wave suffers a
high attenuation in this region. In this research, the effect of rain on radio frequency at this band is investigated with the purpose of developing the attenuation model. The research also evaluates appropriate wideband modulation technique that is suitable for video broadcasting in this band under the influence of rain. In this research, empirical approach was adopted for the model by measuring rain rate data over a period of two years, using the Micro Rain Radar (MRR) situated at the Physics Department, Federal University of Technology, Akure, Nigeria was analyzed. Based on the statistical analysis of the measured data, the effect of rain at 60 GHz frequency band is investigated and a rain attenuation model for the region is developed using an open-source millimetre wave channel simulator, NYUSIM version 1.6; the rain attenuation models at this region for various rain types are developed. The developed rain attenuation models are compared with the ITU-R attenuation model. The results show that attenuation is dependent on the type of rain as defined by the rain rate. Hence attenuation models are developed for the rain type classified. The modulation results from the BER (Bit Error Rate) performance show that DSSS-QPSK and DSSS-BPSK are suitable for sampling rates of 6.75 MHz, 27.0 MHz, 36.0 MHz, 74.25 MHz, while DSSS-16 QAM, DSSS-32 QAM and DSSS-64 QAM are suitable for sampling rates of 18.0 MHz, 148.5 MHz and 800 MHZ, while FHSS-QPSK is suitable for sampling rate of 148.5 MHz; all under the effect of rain at 60 GHz millimetre wave frequency band for this region.
