1.
Vallejo, Luis; Mora, Jose; Ortega, Beatriz; Jin, Wei; Romero, Jaime; Tang, Jianming
Full-Duplex Transmissions in Heterogeneous Fiber-FSO-Wireless Converged Access Networks at Ka-Band Proceedings Article
In: 2025 Joint European Conference on Networks and Communications & 6G Summit (EuCNC/6G Summit), pp. 840–845, 2025, ISSN: 2575-4912, (ISSN: 2575-4912).
Abstract | Links | BibTeX | Tags: 5G mobile communication, B5G, bidirectional heterogeneous networks, converged networks, free-running lasers, Full-duplex system, fullduplex, Heterogeneous networks, Millimeter wave communication, mmWave, Phase shift keying, Radio links, Resource management, RF envelope detection, Throughput, Uplink, Wireless communication
@inproceedings{vallejo_full-duplex_2025,
title = {Full-Duplex Transmissions in Heterogeneous Fiber-FSO-Wireless Converged Access Networks at Ka-Band},
author = {Luis Vallejo and Jose Mora and Beatriz Ortega and Wei Jin and Jaime Romero and Jianming Tang},
url = {https://ieeexplore.ieee.org/document/11037218},
doi = {10.1109/EuCNC/6GSummit63408.2025.11037218},
issn = {2575-4912},
year = {2025},
date = {2025-06-01},
urldate = {2025-10-08},
booktitle = {2025 Joint European Conference on Networks and Communications & 6G Summit (EuCNC/6G Summit)},
pages = {840–845},
abstract = {To overcome the challenges associated with increased demands for mobile capacity and network densification in the 5 G and beyond era, this paper experimentally demonstrates full-duplex heterogeneous fiber-FSO-wireless converged links between the central office-baseband unit (CO-BBU) and the remote radio head (RRH). The centralization of active optical sources for the downlink (DL) and uplink (UL) enables dynamic resource sharing and allocation, optimizing wavelength utilization and improving overall network efficiency. The DL uses a directly modulated laser (DML) with free-running laser-assisted mmWave signal generation and envelope detection for the downstream, transmitting a 100 textbackslashtextMHz 16-textbackslashtextQAM signal at 39 GHz. The UL reuses the DL wavelength for upstream transmission, employing intensity modulation and direct detection (IM-DD) of a 100 MHz QPSK signal at 36.5 GHz. The bidirectional heterogeneous network comprises a 10 km SSMF, a 1.8 m FSO link, and a 3 m wireless radio link, providing flexibility for future networks. The results show successful transmissions of 16-QAM and QPSK signals up to 200 textbackslashtextMbit / textbackslashmathrms and 400 textbackslashtextMbit / textbackslashmathrms for DL and UL, respectively, under the full-duplex transmissions. Additionally, using 5G NR OFDM signals, a maximum bit rate of 2.15 textbackslashtextGbit / textbackslashmathrms and 1.07 Gbit/s is achieved for the DL and UL, respectively, demonstrating the cost-effectiveness of the proposed solution.},
note = {ISSN: 2575-4912},
keywords = {5G mobile communication, B5G, bidirectional heterogeneous networks, converged networks, free-running lasers, Full-duplex system, fullduplex, Heterogeneous networks, Millimeter wave communication, mmWave, Phase shift keying, Radio links, Resource management, RF envelope detection, Throughput, Uplink, Wireless communication},
pubstate = {published},
tppubtype = {inproceedings}
}
To overcome the challenges associated with increased demands for mobile capacity and network densification in the 5 G and beyond era, this paper experimentally demonstrates full-duplex heterogeneous fiber-FSO-wireless converged links between the central office-baseband unit (CO-BBU) and the remote radio head (RRH). The centralization of active optical sources for the downlink (DL) and uplink (UL) enables dynamic resource sharing and allocation, optimizing wavelength utilization and improving overall network efficiency. The DL uses a directly modulated laser (DML) with free-running laser-assisted mmWave signal generation and envelope detection for the downstream, transmitting a 100 textbackslashtextMHz 16-textbackslashtextQAM signal at 39 GHz. The UL reuses the DL wavelength for upstream transmission, employing intensity modulation and direct detection (IM-DD) of a 100 MHz QPSK signal at 36.5 GHz. The bidirectional heterogeneous network comprises a 10 km SSMF, a 1.8 m FSO link, and a 3 m wireless radio link, providing flexibility for future networks. The results show successful transmissions of 16-QAM and QPSK signals up to 200 textbackslashtextMbit / textbackslashmathrms and 400 textbackslashtextMbit / textbackslashmathrms for DL and UL, respectively, under the full-duplex transmissions. Additionally, using 5G NR OFDM signals, a maximum bit rate of 2.15 textbackslashtextGbit / textbackslashmathrms and 1.07 Gbit/s is achieved for the DL and UL, respectively, demonstrating the cost-effectiveness of the proposed solution.
2.
Chen, Yunfei; Khuwaja, Aziz Altaf; Wang, Cheng-Xiang
Effect of Source Signal Traffic on Signal Detection for Ambient Backscatter Communication Journal Article
In: IEEE Transactions on Vehicular Technology, vol. 73, no. 11, pp. 16790–16804, 2024, ISSN: 1939-9359.
Abstract | Links | BibTeX | Tags: Ambient backscatter communications, Backscatter, Indexes, Numerical models, Phase shift keying, Signal detection, Signal to noise ratio, signal traffic
@article{chen_effect_2024,
title = {Effect of Source Signal Traffic on Signal Detection for Ambient Backscatter Communication},
author = {Yunfei Chen and Aziz Altaf Khuwaja and Cheng-Xiang Wang},
url = {https://ieeexplore.ieee.org/document/10572306},
doi = {10.1109/TVT.2024.3419423},
issn = {1939-9359},
year = {2024},
date = {2024-11-01},
urldate = {2025-10-08},
journal = {IEEE Transactions on Vehicular Technology},
volume = {73},
number = {11},
pages = {16790–16804},
abstract = {Ambient backscatter communication (ABC) is a promising method of reducing energy consumption in wireless communications. Previous works on signal detection for ABC often assume that the ambient source signal is always present during backscattering. However, this may not be the case due to the random traffic of the ambient source and the asynchronous operation between source and tag. In this work, the effect of source signal traffic on the detection performance is studied for ABC systems. Firstly, the performances of the existing detectors are analyzed in the presence of source traffic. Both random arrival and random departure are considered. The exponential and uniform traffic models are used. Their bit error rate expressions are obtained by taking advantage of different approximation methods. Then, new detectors taking into account the random traffic models are derived by weighting the samples exponentially or linearly with their arrival times. Numerical results show that the random source traffic could cause large performance degradation to the existing detectors, leading to error floors at small signal-to-noise ratios (SNRs). In particular, the exponential departure causes the largest performance degradation, followed by the uniform arrival and departure. Numerical results also show that the new detectors could have significant performance gains over the conventional detectors in the presence of source traffic. In some case, the gain could be over 3 dB in SNR, and it increases with the sample size and traffic parameters. However, this gain could become negative for large SNRs and small sample sizes due to the use of heuristic detection thresholds.},
keywords = {Ambient backscatter communications, Backscatter, Indexes, Numerical models, Phase shift keying, Signal detection, Signal to noise ratio, signal traffic},
pubstate = {published},
tppubtype = {article}
}
Ambient backscatter communication (ABC) is a promising method of reducing energy consumption in wireless communications. Previous works on signal detection for ABC often assume that the ambient source signal is always present during backscattering. However, this may not be the case due to the random traffic of the ambient source and the asynchronous operation between source and tag. In this work, the effect of source signal traffic on the detection performance is studied for ABC systems. Firstly, the performances of the existing detectors are analyzed in the presence of source traffic. Both random arrival and random departure are considered. The exponential and uniform traffic models are used. Their bit error rate expressions are obtained by taking advantage of different approximation methods. Then, new detectors taking into account the random traffic models are derived by weighting the samples exponentially or linearly with their arrival times. Numerical results show that the random source traffic could cause large performance degradation to the existing detectors, leading to error floors at small signal-to-noise ratios (SNRs). In particular, the exponential departure causes the largest performance degradation, followed by the uniform arrival and departure. Numerical results also show that the new detectors could have significant performance gains over the conventional detectors in the presence of source traffic. In some case, the gain could be over 3 dB in SNR, and it increases with the sample size and traffic parameters. However, this gain could become negative for large SNRs and small sample sizes due to the use of heuristic detection thresholds.