scholarly journals Optical Multilevel Pulse Width Modulation for Analog Mobile Fronthaul

Photonics ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 49
Author(s):  
Lorenzo Combi ◽  
Alberto Gatto ◽  
Pierpaolo Boffi ◽  
Umberto Spagnolini ◽  
Paola Parolari

The evolution of radio access networks is towards a centralized architecture (C-RAN), with massive antenna deployments and large radio-frequency bandwidths. In the next future, traditional optical transport technologies based on digital radio over fiber will no longer be able to support the mobile fronthaul traffic connecting antennas hosted at remote radio units and centralized baseband units. Analog radio over fiber can be selected to support the mobile fronthaul (MFH) network and, in particular, pulse width modulation (PWM) is a viable alternative for analog signal transport. In order to increase the MFH spectral efficiency, we propose to exploit multilevel PWM (M-PWM) in a wavelength division multiplexing-passive optical network (WDM-PON) network, comparing its performance with a conventional 2-level PWM solution. Experimental results show successful transmission over 7.5-km standard single mode fiber (SSMF) of up to 16 aggregated LTE-like 20-MHz signals with 64-QAM on each subcarrier, while up to eight aggregated LTE-like 20-MHz signals with 256-QAM could be supported. M-PWM thus allows either using higher order modulation formats or aggregating a higher number of LTE channels.

2019 ◽  
Vol 9 (21) ◽  
pp. 4520 ◽  
Author(s):  
Mohammed ◽  
Hamdi Mansi

In this work, a record of 16 channels, with future channel spacing in the telecommunication standardization sector of the International Telecommunications Union G.694.1 (ITU-T G.694.1) for Dense Wavelength Division Multiplexing (DWDM) (i.e., 12.5 GHz), is simulated and tested. This work is done to realize a proposed high capacity DWDM-Passive Optical Network (DWDM-PON) system. These specifications are associated with enhancing the upstream (US) capacity to 2.5 Gb/s over a 25 km Single-Mode Fiber (SMF) transmission and producing a noteworthy average Bit Error Rate (BER) of 10−12 during the system’s evaluation process. These performance indicators are achieved through design optimization of the cross-seeding Rayleigh Backscattering (RB) elimination technique. This optimization has successfully reduced (compared to the cross-seeding related literature) the simulated DWDM-PON components and maintained an effective Rayleigh Backscattering elimination with the aforementioned system’s performance enhancement and capacity enlargement.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Maria Morant ◽  
Joaquin Pérez ◽  
Roberto Llorente

This paper describes the state-of-the-art of polarization multiplexing for optical networks transmission. The use of polarization division multiplexing (PDM) permits to multiply the user capacity and increase the spectral efficiency. Combining PDM and orthogonal frequency division multiplexed (OFDM) modulation allows maximizing the optical transmission capacity. The experimental demonstration of transmitting OFDM signals following ECMA-368 ultrawide band (UWB) standard in radio-over-fiber using PDM in passive optical networks is herein reported. The impact of cross-polarization and cochannel crosstalk is evaluated experimentally in a three-user OFDM-UWB subcarrier multiplexed (SCM) configuration per polarization. Each SCM uses up to three OFDM-UWB channels of 200 Mbit/s each, achieving an aggregated bitrate of 1.2 Gbit/s with 0.76 bit/s/Hz spectral efficiency when using PDM transmission. The experimental results for the polarization-multiplexed SCM indicate that a 4 dB additional polarization crosstalk interference can be expected compared to a nonpolarization-multiplexed transmission system which translates to 2.4 dB EVM penalty in the UWB signals. The successful PDM transmission of SCM multiuser OFDM-UWB over a passive optical network of 25 km standard-single mode fiber (SSMF) reach is demonstrated.


Photonics ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 328
Author(s):  
Haoyi Wang ◽  
Pablo Torres-Ferrera ◽  
Valter Ferrero ◽  
Roberto Gaudino

In this paper we present an experimental analysis of several modulation formats (pulse amplitude modulation (PAM-2), quaternary pulse amplitude modulation (PAM-4) and electrical duobinary (EDB)) for passive optical network (PON) applications at 25 Gbps bit rate in a C-band 10G-class directly modulated lasers (DML) and avalanche photodiode (APD) intensity modulation and direct detection (IM-DD) system over a single mode fiber (SMF) of up to 25 km, optimizing DML operations and demonstrating that PAM-2 is a promising choice. We also theoretically and experimentally analyzed the channel frequency response of DML and SMF affected by DML chirp and SMF chromatic dispersion.


2015 ◽  
Vol 36 (2) ◽  
Author(s):  
Vikrant Sharma ◽  
Anurag Sharma ◽  
Dalvir Kaur

AbstractIn this paper, performance analysis of high-speed superdense wavelength-division-multiplexing (SDWDM) optical add–drop multiplexer (OADM) optical ring network for 6 nodes, 45 wavelengths having channel spacing of 0.2 nm on 300 km unidirectional nonlinear single-mode fiber ring of 10 Gbit/s has been reported. The performance optimization of the system by comparing different modulation formats has been reported on the basis of eye diagram and bit error rate (BER). It has been reported that CSRZ modulation format can achieve BER as better as e-24, which gives best performance. This paper also presents a study of performance degradation caused by the crosstalk and the effect of channel spacing on SWDM system.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Shuai Chen ◽  
Wei Nai ◽  
Fangqi Zhang ◽  
Shaoyin Wang ◽  
Decun Dong ◽  
...  

Wavelength-division-multiplexing passive-optical-network (WDM-PON) has been recognized as a promising solution of the “last mile” access as well as multibroadband data services access for end users, and WDM-RoF-PON, which employs radio-over-fiber (RoF) technique in WDM-PON, is even a more attractive approach for future broadband fiber and wireless access for its strong availability of centralized multiservices transmission operation and its transparency for bandwidth and signal modulation formats. As for multiservices development in WDM-RoF-PON, various system designs have been reported and verified via simulation or experiment till now, and the scheme with multiservices transmitted in each single wavelength channel is believed as the one that has the highest bandwidth efficiency; however, the corresponding mathematical verification is still hard to be found in state-of-the-art literature. In this paper, system design and data transmission performance of a quintuple services integrated WDM-RoF-PON which jointly employs carrier multiplexing and orthogonal modulation techniques, have been theoretically analyzed and verified in detail; moreover, the system design has been duplicated and verified experimentally and the theory system of such WDM-RoF-PON scheme has thus been formed.


2021 ◽  
Author(s):  
Meet Kumari ◽  
Anu Sheetal ◽  
Reecha Sharma

Abstract In this work, a full-duplex time and wavelength division multiplexing-passive optical network (TWDM-PON) system is analysed. Orthogonal frequency division multiplexing (OFDM) with m-quadrature amplitude modulation (m-QAM) is employed to improve the performance of TWDM-PON for downstream and upstream transmission. Simultaneously, multi-color (390–750 nm) laser diodes (LDs) are employed for visible light communication (VLC) using various VLC links to encourage the information rate of fiber/VLC optical network. A TWDM-PON utilizing 16-, 32- and 64-QAM OFDM with ten LDs based VLC system has been analysed for full-duplex multi-color VLC signals of the system. The impact of the LDs input current and high transmission rate in the proposed PON/VLC link has been investigated for m-QAM OFDM modulation. The results show that the 40/40 Gbps 16-, 32- and 64-QAM signals over ten 8000 m VLC links and a 50 km fiber link are successfully transmitted at the modulation input current of 9 mA under bit error rate (BER) of 3.8×10− 3. Also, the proposed system employing 16-, 32- and 64-QAM signals over a 10 km fiber and ten 10 m VLC links provide the maximum transmission rate of 120, 100 and 80 Gbps respectively. Moreover, the measured error vector magnitudes (EVMs) and calculated BER values for 16-QAM downstream and upstream signals, are well below the required FEC limit than high-order modulation formats. Further, the numerical analysis of the proposed system reveals the superiority of the proposed fiber/VLC links.


2015 ◽  
Vol 15 (10) ◽  
pp. 7462-7466
Author(s):  
Su Hwan Oh ◽  
Ki-Hong Yoon ◽  
Seung-Hyun Cho ◽  
Jun-Kyu Seo

We report the transmission capability of a tunable external cavity laser (T-ECL) that utilizes a super-luminescent diode (SLD) and a polymer Bragg reflector (PBR) operating with a direct modulation of 2.5 Gb/s for a light source of a long-reach wavelength division multiplexed-passive optical network (WDM-PON). The T-ECL successfully operated at an ambient temperature of −20 °C to 70 °C when employing a cooled SLD. A tuning range of 12-nm is achieved with a tuning power of lower than 80 mW. A side mode suppression ratio of more than 35 dB was obtained for the whole tuning range. The linewidth of the lasing spectrum is less than 0.1 nm at 20 dB from the peak power. The transmission performance of the T-ECL, including an optical bandpass filter (OBPF), is better than that of the T-ECL excluding an OBPF for a long-reach transmission over 80 km of single mode fiber (SMF). The power penalty of the T-ECL is less than 1.4 dB when using an OBPF for an 80-km transmission.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Shahab Ahmad Niazi ◽  
Xiaoguang Zhang ◽  
Lixia Xi ◽  
Abid Munir ◽  
Muhammad Idrees ◽  
...  

International Telecommunication Union (ITU) has recently standardized ultrahigh definition television (UHD-TV) with a resolution 16 times more than the current high definition TV. An increase in the efficiency of video source coding or in the capacity of transmission channels will be needed to deliver such programs by passive optical network (PON). In this paper, a high capacity integrated PON infrastructure is proposed to overlay ultrahigh definition television by a complete passive coexistence of 10G-PON (XG-PON) and single carrier directly modulated, duo-binary 40G-PON (XLG-PON) signal. The simulation results show error-free transmission performance and further distribution to 32 optical network units (ONUs) on broadcast basis with negligible power penalty over 20 km of bidirectional standard single mode fiber.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Navjot Singh ◽  
Bharat Naresh Bansal

Abstract Wavelength division multiplexed passive optical is promising technique to achieve a high data rate and large number of user. The notable advantages of WDM PON is the combination of reliability, cheap in cost, accessible bandwidth, high security, large optical reach and it can support large number of ONU. There are multiple approaches to achieve high-speed WDN PON using different transmission techniques. In WDM, multiple lasers are required which increase the cost of the system. To reduce cost, an optical multicarrier generation system is proposed. An economical multiple carrier generation with the incorporation of sine generator and Mach–Zehndar modulator is demonstrated. Utmost work of sine generator and dual drive modulator was to attain low cost functioning of passive optical networks. Multicarrier generation was done and replacement of laser carriers with optical multicarrier generator. Carriers were generated with the frequency spacing of 20 GHz and these carriers were used in the passive optical networks with the tone-to-noise ratio of 40 dB, amplitude difference of 1.4 dB. For the transmission of downstream in the PON, differential phase shift keying was employed at 10 Gbps data speed. Transmission distance achieved was 30 km using single-mode fiber and this was a part of optical distribution network. Optical network unit was next part after ODN and signals were received with balanced receiver. Moreover, half signal was given to intensity modulator for the signal re-modulation. Bit error rate of 10–9 was achieved at all channels in the downstream. An upstream of 10 Gbps was accomplished in the passive optical network.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Shuai Zhang ◽  
Liqun Huang ◽  
Mingxu Zhu

In order to effectively solve the problem of data transmission security and peak-to-average ratio (PAPR) in an orthogonal frequency division multiplexing passive optical network (OFDM-PON) transmission system, in this paper, a joint encryption scheme of discrete cosine transform (DCT) and selective mapping (SLM) based on chaotic mapping is proposed. In this scheme, the chaotic sequence of a 3D Lorenz chaotic system is used as the row and column index of the DCT matrix and the phase factor of SLM to resist selective plaintext attack, and the system encryption is realized while reducing PAPR. The theoretical analysis and numerical simulation show that the common OFDM-PON, the proposed algorithm, can obtain a PAPR suppression gain of ∼4.8 dB and improve the receiver sensitivity by ∼4 dB BER @ 10 − 3 . In addition, it shows that, with the increase of row/column index mismatch of the DCT matrix, the bit error rate of the system increases gradually. An encrypted data transmission of 8 GB/s 16-QAM optical OFDM signals is successfully simulated over a 20 km standard single-mode fiber, which proves the excellent confidentiality of the proposed secure transmission.


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