Page 620 - 5G Basics - Core Network Aspects

2 Transport aspects

Figure 9-9 – Measured RF spectra before E/O conversion (upper)
and after O/E conversion (lower)
The measured EVM as a function of an additional optical link loss after the 20 km SMF transmission is
shown in Figure 9-10. We measured the EVMs at the lowest IF carrier frequency of 270 MHz (EVM at RoF-
Rx) and the RF carrier (2 660 MHz) frequency (EVM at antenna) to investigate the transmission
performance degradations caused by the frequency-up-conversion process. From the measured EVMs and
the requirements at the BS (see [b-3GPP TS 36.104]), it can be seen that the optical loss budget can thus be
as high as 31 dB, meeting the N1 and N2 loss budget requirements for passive optical networks. From the
above, it can be concluded that IF-band SCM RoF transmission scheme is also feasible.

20
18
16
14
12
EVM [%] 10 8 Required EVM for 64-QAM signal (~8%)
ODN N2 class

6
4
2
0
0 5 10 15 20 25 30 35 40
Optical path loss [dB]
EVM at RoF-Rx with EDFA
EVM at antenna with EDFA
EVM at RoF-Rx without EDFA
EVM at antenna without EDFA G Suppl.55(15)_F9-10

Figure 9-10 – Measured EVM as a function of an additional optical link
loss after 20 km-long SMF transmission

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