Radio propagation at 900 MHz in urban areas: Models with a fixed frequency and experimental results
Abstract
Models which describe multipath propagation are examined in order to design a 900 MHz mobile communication system adapted to urban areas. A justification of the experimental data treatment is derived from this analysis. The measurements were made at a fixed 855 MHz frequency, transmitting from three locations. The fast fluctuations of the received signals are well represented by a Rayleigh process, which means that there are practically no paths of direct transmission. The coherence length is 1 m. The statistical distribution of the average field is Gaussian and the normal deviation decreases with the distance emitter-receiver. The empiric Okumura-Hata prediction model agrees well with the experimental results, giving an average cell field decreasing with distance with a logarithmic law.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- September 1984
- Bibcode:
- 1984STIN...8629126O
- Keywords:
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- Cities;
- Mobile Communication Systems;
- Multipath Transmission;
- Rayleigh Distribution;
- Signal Fading;
- Wave Propagation;
- Decimeter Waves;
- Mathematical Models;
- Reception Diversity;
- Statistical Distributions;
- Communications and Radar