Log Distance Path Loss Model
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The Log Distance Path Loss Model is an indoor Radio propagation model that predicts the path loss a signal encounters inside a building over distance.
Contents |
[edit] Applicable to / Under conditions
The model is applicable to indoor propagation modeling.
[edit] Mathematical Formulation
[edit] The model
Log Distance Path Loss model is formally expressed as:
where,
L = The total path loss inside a building. Unit:Decibel (dB)
L0 = The path loss at reference distance, usually, 1 km or 1 mile. Unit: Decibel (dB)
γ = The path loss distance exponent.
Xg = A Gaussian random variable with zero mean and 
standard deviation, reflecting the shadow fading or slow fading.
[edit] Calculation of empirical coefficients
The coefficients 10γ and σ in dB are calculated as follows. [1]
| Building Type | Frequency of Transmission | 10γ | σ |
|---|---|---|---|
| Retail store | 914 MHz | 22 | 8.7 |
| Grocery store | 914 MHz | 18 | 5.2 |
| Office with hard paritition | 1.5 GHz | 30 | 7 |
| office with soft partition | 900 MHz | 24 | 9.6 |
| office with soft partition | 1.9 GHz | 26 | 14.1 |
| Textile or chemical | 1.3 GHz | 20 | 3.0 |
| Textile or chemical | 4 GHz | 21 | 7.0, 9.7 |
| Metalworking | 1.3 GHz | 16 | 5.8 |
| Metalworking | 1.3 GHz | 33 | 6.8 |
[edit] References
- ^ Wireless communications principles and practices, T. S. Rappaport, 2002, Prentice-Hall
[edit] Further reading
- Introduction to RF propagation, John S. Seybold, 2005, Wiley.
- Wireless communications principles and practices, T. S. Rappaport, 2002, Prentice-Hall.
