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发表于 2010-7-15 10:45:18
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Conversion between field strength and propagation loss
The field strength, E1546 directly predicted by Rec. ITU-R P.1546-3, assumes a transmitter ERP = 0 dBkW; E1546 is expressed in units of dBV/m. For an arbitrary ERPdBkW, the predicted field strength, E1546, expressed in units of dBV/m, is
E1546 = E1546 + ERPdBkW
The propagation loss (‘LOSS’) predicted by the Hata model is expressed in dB (i.e., independent of transmitter power).
The relationship between predicted field strength, E1546 (i.e., for ERP = 0 dBkW), and the predicted propagation loss, LOSSdB, for a given frequency (fMHz) measured in MHz, is the following:
E1546 = 139.3 + 20 log fMHz – LossdB;
LossdB = 139.3 + 20 log fMHz – E1546.
For any given ERPdBkW, the corresponding relationship between E1546 and the predicted propagation loss, for a given frequency (fMHz), is the following:
E1546 = 139.3 + 20 log fMHz – LossdB + ERPdBkW;
LossdB = 139.3 + 20 log fMHz – E1546 + ERPdBkW. |
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