| 1. |
- Hagen, Espen, et al.
(författare)
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Hybrid Scheme for Modeling Local Field Potentials from Point-Neuron Networks
- 2016
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Ingår i: Cerebral Cortex. - : OXFORD UNIV PRESS INC. - 1047-3211 .- 1460-2199. ; 26:12, s. 4461-4496
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Tidskriftsartikel (refereegranskat)abstract
- With rapidly advancing multi-electrode recording technology, the local field potential (LFP) has again become a popular measure of neuronal activity in both research and clinical applications. Proper understanding of the LFP requires detailed mathematical modeling incorporating the anatomical and electrophysiological features of neurons near the recording electrode, as well as synaptic inputs from the entire network. Here we propose a hybrid modeling scheme combining efficient point-neuron network models with biophysical principles underlying LFP generation by real neurons. The LFP predictions rely on populations of network-equivalent multicompartment neuron models with layer-specific synaptic connectivity, can be used with an arbitrary number of point-neuron network populations, and allows for a full separation of simulated network dynamics and LFPs. We apply the scheme to a full-scale cortical network model for a similar to 1 mm(2) patch of primary visual cortex, predict laminar LFPs for different network states, assess the relative LFP contribution from different laminar populations, and investigate effects of input correlations and neuron density on the LFP. The generic nature of the hybrid scheme and its public implementation in hybridLFPy form the basis for LFP predictions from other and larger point-neuron network models, as well as extensions of the current application with additional biological detail.
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| 2. |
- Han, Mengyao, et al.
(författare)
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Deep Reservoir Computing for 100 Gbaud PAM6 IM/DD Transmission Impairment Mitigation
- 2023
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Ingår i: 2023 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION, OFC. - : Optica Publishing Group.
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Konferensbidrag (refereegranskat)abstract
- We experimentally evaluate a deep Reservoir Computing (RC)-based post-equalization for 100 Gbaud PAM6 IM/DD transmissions. It achieves similar to 1 dB higher sensitivity than DFE, and similar to 50% implementation complexity reduction compared with the conventional RC configuration.
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| 3. |
- Ostrovskis, Armands, et al.
(författare)
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170 Gbaud On-Off-Keying SiP Ring Resonator Modulator-based Link for Short-Reach Applications
- 2024
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Ingår i: 2024 IEEE Silicon Photonics Conference, SiPhotonics 2024 - Proceedings. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- We demonstrate a record 170 Gbaud on-off keying C-band silicon photonics ring resonator modulator-based transmitter with performance below the 6.7% overhead HD-FEC threshold after optical back-to-back and transmission over 100 meters of single mode fiber.
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| 4. |
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| 5. |
- Ozolins, Oskars, et al.
(författare)
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106.25 Gbaud 4-Level Pulse Amplitude Modulation Links Supporting (2x)100Gigabit Ethernet on Single Lambda
- 2023
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Ingår i: 2023 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION, OFC. - : Institute of Electrical and Electronics Engineers Inc..
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Konferensbidrag (refereegranskat)abstract
- We experimentally demonstrate and compare EML- and DML-based optical interconnects with 106.25 Gbaud NRZ-OOK and PAM4 for computing applications. The results show that both transmitters can be used to enable optical -amplification-free transmissions with low-complexity DSP.
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| 6. |
- Ozolins, Oskars, et al.
(författare)
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300 Gbps Short-Reach C-Band Optical Links
- 2020
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Ingår i: 2020 22nd international conference on transparent optical networks (ICTON 2020). - : IEEE. - 2162-7339. - 9781728184234
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Konferensbidrag (refereegranskat)
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| 7. |
- Ozolins, Oskars, et al.
(författare)
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High Baudrate Short-Reach Communication
- 2022
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Ingår i: Proceedings OECC/PSC 2022 - 27th OptoElectronics and Communications Conference/International Conference on Photonics in Switching and Computing 2022. - : Institute of Electrical and Electronics Engineers (IEEE). - 9784885523366
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Konferensbidrag (refereegranskat)abstract
- We demonstrate a 200 Gbps IM/DD link without any optical amplification using C-band externally modulated laser with 3.3 dBm of modulated output power and O-band directly modulated laser with 7.3 dBm of modulated output power.
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| 8. |
- Ozolins, Oskars, et al.
(författare)
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High-Baudrate Silicon Photonics Ring Resonator and Mach-Zehnder Modulators for Short-Reach Applications
- 2023
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Ingår i: 2023 23rd International Conference on Transparent Optical Networks, ICTON 2023. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- Silicon photonics (SiP) is a key enabling technology for high-baudrate communication. It is a key technology for future 800 Gbps and 1.6 Tbps solutions to meet the ever-increasing demands. The 800G pluggable multi-source agreement (MSA) suggests that intensity-modulated direct-detection (IM/DD) is the most sustainable way forward [1]. The high operational bandwidth of each transceiver component is essential. An ultra-compact SiP slow light modulator with record-high bandwidth of 110 GHz shows the potential [2]. Therefore, both multilevel pulse amplitude modulation (PAM) and on-off keying (OOK) should be considered. SiP offers excellent production yield and has a substantial role in optical interconnects. SiP ring resonator modulators (RRM) have unique advantages like a small footprint, simple driver configuration, low power consumption, and suitability for multichannel applications. On the other hand, the SiP Mach-Zehnder modulator (MZM) offers differential drive benefits.
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| 9. |
- Ozolins, Oskars, et al.
(författare)
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High-Baudrate Silicon Photonics Ring Resonator Modulators for Short-Reach Applications
- 2023
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Ingår i: 2023 Asia Communications and Photonics Conference/2023 International Photonics and Optoelectronics Meetings, ACP/POEM 2023. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- We demonstrate up to 160 Gbaud on-off keying with first ring resonator modulator and up to 128 Gbaud on-off keying with second ring resonator modulator. Both modulators achieve performance below 6.25% OH HD-FEC threshold.
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| 10. |
- Ozolins, Oskars, et al.
(författare)
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High-Baudrate SiP and InP Modulators for Data Center Interconnects
- 2023
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Ingår i: 2023 31st International Conference on Software, Telecommunications and Computer Networks, SoftCOM 2023. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- The booming internet traffic sets highly challenging requirements for high-speed computing where low latency is required. This leads to a choice of intensity modulation and direct detection system with the highest baudrate possible. Furthermore, record baudrate supporting modulators will be the key technology for future optical interconnect applications. Therefore, we demonstrated silicon photonics and indium phosphide modulators at highest possible sysmbolrate.
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| 11. |
- Ozolins, Oskars, et al.
(författare)
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Optical Amplification-Free 200 Gbaud On-Off Keying Link for Intra-Data Center Communications
- 2022
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Ingår i: 2022 Optical Fiber Communications Conference and Exhibition, OFC 2022 - Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. - 9781557524669
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Konferensbidrag (refereegranskat)abstract
- We demonstrate a 200 Gbaud OOK link without any optical amplification using C-band externally modulated laser with 3.3 dBm of modulated output power. We achieve below 6.25% overhead HD-FEC threshold after 200 meters of SMF. © 2022 The Author(s)
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| 12. |
- Ozolins, Oskars, et al.
(författare)
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Optical Amplification-Free 200 Gbaud On-Off Keying Link for Intra-Data Center Communications
- 2016
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Ingår i: Optical Fiber Communication Conference, OFC 2016. - : Optica Publishing Group (formerly OSA).
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Konferensbidrag (refereegranskat)abstract
- We demonstrate a 200 Gbaud OOK link without any optical amplification using C-band externally modulated laser with 3.3 dBm of modulated output power. We achieve below 6.25% overhead HD-FEC threshold after 200 meters of SMF.
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| 13. |
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| 14. |
- Ozolins, Oskars, et al.
(författare)
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Optical Amplification-Free High Baudrate Links for Intra-Data Center Communications
- 2023
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Ingår i: Journal of Lightwave Technology. - : Institute of Electrical and Electronics Engineers Inc.. - 0733-8724 .- 1558-2213.
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Tidskriftsartikel (refereegranskat)abstract
- The enormous traffic growth sets a stringent requirement to upgrade short-reach optical links to 1.6 TbE capacity in an economically viable way. The power consumption and latency in these links should be as low as possible, especially for high-speed computing. This is possible to achieve using high baudrate on-off keying links thanks to a better noise tolerance and a relaxed requirement on linearity for electronics and photonics. In this regard, we demonstrate a 200 Gbaud on-off keying link without any optical amplification using an externally modulated laser with 3.3 dBm of modulated output power operating at 1541.25 nm wavelength. We achieve transmission over 200 meters of single-mode fiber with performance below 6.25% overhead hard-decision forward error correction threshold for each baudrate and all selection of modulation formats. We also show 108 Gbaud on-off keying link with superior performance without decision feedback equalizer up to 400 meters of single-mode fiber. In addition, we benchmark the short-reach optical link with 112 Gbaud four-level pulse amplitude modulation and 100 Gbaud six-level pulse amplitude modulation. For 108 Gbaud on-off keying and 112 Gbaud four-level pulse amplitude modulation, we can achieve an even lower bit error rate.
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| 15. |
- Paetzold, Martin, et al.
(författare)
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Rosetta Radio Science Investigations (RSI)
- 2007
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Ingår i: Space Science Reviews. - : Springer Science and Business Media LLC. - 0038-6308 .- 1572-9672. ; 128:1-4, s. 599-627
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Forskningsöversikt (refereegranskat)abstract
- The Rosetta spacecraft has been successfully launched on 2nd March 2004 to its new target comet 67 P/Churyurnov-Gerasimenko. The science objectives of the Rosetta Radio Science Investigations (RSI) experiment address fundamental aspects of cometary physics such as the mass and bulk density of the nucleus, its gravity field, its interplanetary orbit perturbed by nongravitational forces, its size and shape, its internal structure, the composition and roughness of the nucleus surface, the abundance of large dust grains, the plasma content in the coma and the combined dust and gas mass flux. The masses of two asteroids, Steins and Lutetia, shall be determined during flybys in 2008 and 2010. respectively. Secondary objectives are the radio sounding of the solar corona during the superior conjunctions of the spacecraft with the Sun during the cruise phase. The radio carrier links of the spacecraft Telemetry, Tracking and Command (TT&C) subsystem between the orbiter and the Earth will be used for these investigations. An Ultrastable oscillator (USO) connected to both transponders of the radio subsystem serves as a stable frequency reference source for both radio downlinks at X-band (8.4 GHz) and S-band (2.3 GHz) in the one-way mode. The Simultaneous and coherent dual-frequency downlinks via the High Gain Antenna (HGA) permit separation of contributions from the classical Doppler shift and the dispersive media effects caused by the motion of the spacecraft with respect to the Earth and the propagation of the signals through the dispersive media, respectively.
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| 16. |
- Pang, Xiaodan, Dr., et al.
(författare)
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200 Gb/s Optical-Amplifier-Free IM/DD Transmissions using a Directly Modulated O-band DFB+R Laser targeting LR Applications
- 2023
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Ingår i: Journal of Lightwave Technology. - : Institute of Electrical and Electronics Engineers Inc.. - 0733-8724 .- 1558-2213. ; 41:11, s. 3635-
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Tidskriftsartikel (refereegranskat)abstract
- We experimentally demonstrate an O-band single-lane 200 Gb/s intensity modulation direct detection (IM/DD) transmission system using a low-chirp, broadband, and high-power directly modulated laser (DML). The employed laser is an isolator-free packaged module with over 65-GHz modulation bandwidth enabled by a distributed feedback plus passive waveguide reflection (DFB+R) design. We transmit high baud rate signals over 20-km standard single-mode fiber (SSMF) without using any optical amplifiers and demodulate them with reasonably low-complexity digital equalizers. We generate and detect up to 170 Gbaud non-return-to-zero on-off-keying (NRZ-OOK), 112 Gbaud 4-level pulse amplitude modulation (PAM4), and 100 Gbaud PAM6 in the optical back-to-back configuration. After transmission over the 20-km optical-amplifier-free SSMF link, up to 150 Gbaud NRZ-OOK, 106 Gbaud PAM4, and 80 Gbaud PAM6 signals are successfully received and demodulated, achieving bit error rate (BER) performance below the 6.25%-overhead hard-decision (HD) forward-error-correction code (FEC) limit. The demonstrated results show the possibility of meeting the strict requirements towards the development of 200Gb/s/lane IM/DD technologies, targeting 800Gb/s and 1.6Tb/s LR applications.
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| 17. |
- Puerta, Rafael, et al.
(författare)
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Analog Mobile Fronthaul for 6G and Beyond
- 2024
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Ingår i: Journal of Lightwave Technology. - : Institute of Electrical and Electronics Engineers Inc.. - 0733-8724 .- 1558-2213.
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Tidskriftsartikel (refereegranskat)abstract
- This paper highlights the potential of photonic-assisted analog fronthaul solutions, particularly analog radio-over-fiber (ARoF) and analog radio-over-free-space-optics (ARoFSO), as prospective alternatives for the development of 6G applications. First, we present (New-Radio) NR/5G conformance testing of ARoF and ARoFSO fronthaul links, including the assessment of the error vector magnitude (EVM) and adjacent channel leakage power ratio (ACLR) to demonstrate compliance with the minimum transmitter requirements outlined by the 3rd Generation Partnership Project (3GPP) standards. Then, with focus on future 6G Distributed-MIMO (D-MIMO) networks, we conduct experimental validations of coherent joint transmissions (CJT) using ARoF and ARoFSO fronthaul links in a 2-transmitter D-MIMO network, demonstrating MIMO gains of up to 5.35 dB and that these links meet the stringent synchronization demands for CJT. These tests represent the first realizations of CJT utilizing ARoF and ARoFSO links. Finally, for consistency, we validate CJT in a 4-transmitter D-MIMO network with ARoF fronthaul links, with MIMO gains up to 9.4 dB and confirming our previous results. This evidence indicates that these technologies hold significant potential for applications in future 6G systems.
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