[EN] In this paper, we experimentally demonstrate the feasibility of a phase modulation (PM)-based analog optical mobile fronthaul network for seamless millimeter wave (mmWave) signal transmission over hybrid standard single-mode fiber (SSMF), free space optics (FSO) and radio links. As a proof of concept, a 64-QAM LTE signal has been transmitted over 25 GHz in a 10 km SSMF, 2 m FSO and 1 m radio link without the need for optical amplifiers. After fiber propagation, non-significant signal degradation has been obtained over the wireless links, with an estimated sensitivity level of received electrical power -45.8 dBm. Despite the advantages of PM-based approaches, the use of optical filtering in our system provides easy scalability by including dense wavelength division multiplexing (DWDM) schemes. Also, the comparison with direct intensity modulation (IM)-based approach allows to assess PM-approach as a promising solution for seamless mmWave signal transmission over future networks., This work has been supported TACR grant FW03010551 and within COST action CA19111 (NEWFOCUS). It has also been funded by Grant PID2021-126514OB-I00 OPTIMISE by MCIN/AEI/ 10.13039/501100011033 and
ERDF A way of making Europe .

[EN] This paper presents the viability of two different
approaches based on external modulation for millimeter wave
(mmW) signal generation that are demonstrated over two full
duplex photonic fronthaul schemes. Both intensity and phase
modulation are demonstrated as effective techniques for mmW
signal generation and also, in both cases, local oscillator remote
delivering is provided, whereas a centralized scheme provides an
optical carrier for uplink which is delivered from the central
station. Wireless transmission is performed through both radio
and free-space optics links. Experimental transmission results
with QPSK and 64-QAM test model signals show both solutions
as promising for the future mobile communication networks., This work has been supported by COST action CA19111 (NEWFOCUS) and Grant PID2021-126514OB-I00 OPTIMISE by MCIN/AEI/10.13039/501100011033 and ERDF A way of making Europe and TACR
grant : FW07010035.

[EN] In this paper, we present a detailed characterization of a phase modulation (PM)–based approach employing optical filtering for photonic millimeter-wave (mmW) signal generation. Simulations and experimental results exhibit very good agreement, showing that both the bandwidth and the notch peak of the optical filter lead to the overall system response, with up to 15 dB electrical gain in the mmW band, also due to the combination of laser chirp and 10 km fiber dispersion. The system error-vector-magnitude (EVM) performance for a 25 MHz bandwidth QPSK signal is characterized over a wide range of electrical mmW power values and frequencies, while intermodulation distortion appears at high power levels. Accordingly, in the linear regime, it is observed that the 10 km SSMF link yields improved EVM values compared to OB2B in terms of RoP, while measurements for different ReP values show the transparency of this approach with no further degradation with respect to EB2B tests. Therefore, this method is confirmed as very promising for future deployment of mmW-based communication networks using photonic technologies for signal generation and transmission., The research leading to these results has received funding from Generalitat Valenciana (PROMETEO 2021/015)
and MCIN/AEI/10.13039/501100011033 and ERDF A way of making Europe by Grant PID2021-126514OBI00 OPTIMISE.