Evaluation of the MODCOD and (GT) required » History » Version 1
AUGER, Anne sophie, 03/24/2015 11:56 AM
| 1 | 1 | AUGER, Anne sophie | h1. Evaluation of the MODCOD and (GT) required |
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| 4 | 1 | AUGER, Anne sophie | Supposing that the specifications and frequency band are known (_Rb, R, f, B_ and _EIRP_ are known), we directly get all the parameters for the system design by following the method described previously. |
| 5 | 1 | AUGER, Anne sophie | |
| 6 | 1 | AUGER, Anne sophie | _+f= 869,5 MHz B= 250 kHz PAR= 0.5 W Rb=500 bits/s R=50 km:+_ |
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| 8 | 1 | AUGER, Anne sophie | p=. !850M-MODCOD-GoT.png! |
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| 12 | 1 | AUGER, Anne sophie | _+f= 5 GHz B= 500 kHz EIRP= 1 W Rb=500 bits/s R=50 km:+_ |
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| 15 | 1 | AUGER, Anne sophie | p=. !5G-MODCOD-GoT.png! |
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| 19 | 1 | AUGER, Anne sophie | We can see from these two simulations that: |
| 20 | 1 | AUGER, Anne sophie | * The higher the Bandwidth, the lower the Modcod |
| 21 | 1 | AUGER, Anne sophie | * The higher the frequency, the higher the free space loss, and then the higher the (G/T) and EIRP requested to compensate these losses. |
| 22 | 1 | AUGER, Anne sophie | |
| 23 | 1 | AUGER, Anne sophie | Moreover, we can evaluate the requested gain of the antennas from the (G/T) values. In fact, we have been told by Mr Perrin that the receivers temperature was between 400K and 600K, depending on the quality receiver and the directivity of the antenna (looking toward the ground or not?). |
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| 25 | 1 | AUGER, Anne sophie | Then, a (G/T) of -27.3 dB corresponds more or less to an isotropic antenna, and a (G/T) of -16.9 dB corresponds to a 9 dB gain antenna, which is easily feasible at the 5 GHz frequency. |