2.4.1.4.2.2.4 Max RF Power (indoor conditions)
Only location point 26 gives an indication of the RF power needed in indoor situations (P 23 dBm at 20 km) but the experimentation conditions were not appropriate as no TV signals could be received. Further trials would be performed when Metz was covered by a DVB-T gap-filler transmitter (to be addressed by the MOTIVATE project trials at the end of 1998).
The experiments based on the Metz test platform have shown results confirming the general feasibility of the SFDMA system for providing return link access in UHF channels. The results are consistent with the theoretical calculations made on the RF parameters, especially on the transmission power needed to enable a service range compatible with television reception.
However, further trials need to be performed on a second generation demonstration equipment that will offer easier and optimized set-up capabilities, in order to consolidate the different RF parameters and to test new configurations such as the indoor mode.
Before mounting the different equipment on the experimentation site, laboratory measurements gave the following performance for the receiver for signal level/BER at 757 MHz:
TABLE 2 .6
Return channel receiver performance
Rx level
(dBm)
|
BER after 5 min
|
–40
|
Sync loss (receiver saturation)
|
–42
|
2 10–2
|
–47
|
2 10–4
|
–53
|
0
|
–63
|
0
|
–73
|
0
|
–77
|
2 10–5
|
–83
|
2 10–4 (sensibility threshold)
|
–87
|
1.5 10–3
|
–93
|
1.6 10–2
|
–93
|
Sync loss
|
It can be seen that a 36 dB dynamic range [–47 to –83 dBm] is available for BER measurements down to 10– 4.
FIGURE 2.8 [2025-028]
FIGURE 2.9 [2025-029]
FIGURE 2.10 [2025-0210]
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