26 research outputs found
High Dimensional Modulation and MIMO Techniques for Access Networks
Exploration of advanced modulation formats and multiplexing techniques
for next generation optical access networks are of interest as promising
solutions for delivering multiple services to end-users. This thesis addresses
this from two different angles: high dimensionality carrierless amplitudephase
(CAP) and multiple-input multiple-output (MIMO) radio-over-fiber
(RoF) systems.
High dimensionality CAP modulation has been investigated in optical
fiber systems. In this project we conducted the first experimental demonstration
of 3 and 4 dimensional CAP with bit rates up to 10 Gb/s. These
results indicate the potentiality of supporting multiple users with converged
services. At the same time, orthogonal division multiple access
(ODMA) systems for multiple possible dimensions of CAP modulation has
been demonstrated for user and service allocation in wavelength division
multiplexing (WDM) optical access network.
2 x 2 MIMO RoF employing orthogonal frequency division multiplexing
(OFDM) with 5.6 GHz RoF signaling over all-vertical cavity surface
emitting lasers (VCSEL) WDM passive optical networks (PONs). We have
employed polarization division multiplexing (PDM) to further increase the
capacity per wavelength of the femto-cell network. Bit rate up to 1.59 Gbps
with fiber-wireless transmission over 1 m air distance is demonstrated.
The results presented in this thesis demonstrate the feasibility of high
dimensionality CAP in increasing the number of dimensions and their potentially
to be utilized for multiple service allocation to different users.
MIMO multiplexing techniques with OFDM provides the scalability in increasing
spectral effciency and bit rates for RoF systems.
High dimensional CAP and MIMO multiplexing techniques are two
promising solutions for supporting wired and hybrid wired-wireless access
networks
Performance Analysis of Carrier-Aggregated Multi-Antenna 4Ă—4 MIMO LTE-A Fronthaul by Spatial Multiplexing on Multicore Fiber
© 2018 IEEE. Personal use of this material is permitted. PermissĂon from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertisĂng or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.[EN] In this paper,we experimentally propose and evaluate the performance of multiantenna LTE-Advanced (LTE-A) systems implementing multiple-input-multiple-output (MIMO) space divisiĂłn multiplexing on multicore fiber, compared to single-antenna single-antenna system (SISO) transmissions. Fully standard 3GPP LTE-A cellular signals are transmitted with MIMO and carrier aggregation in radio-over-fiber over a four-core fiber in different configurations. The processing capabilities of in-built 3GPP MIMO processing are evaluated experimentally in two-antenna and four-antenna LTE-A configurations and compared with single-antenna SISO performance. The robustness of 3GPP MIMO processing is analyzed over different optical paths in a four-core fiber and the optical power margin available between the four optical paths is calculated for each configuration. Finally, the transmission performance of carrier-aggregated LTE-A signals is evaluated in the four-antenna system implementing 4Ă—4 MIMO spatial multiplexing with different carrier separation and center frequency configurations, including regulated cellular frequencies of frequency division duplex bands 7 and 20.This work was supported in part by Spain National Plan MINECO/FEDER UE TEC2015-70858-C2-1-R XCORE and RTC-2014-2232-3 HIDRASENSE. The work of M. Morant was supported by UPV postdoc PAID-10-16 Program.Morant, M.; Llorente, R. (2018). Performance Analysis of Carrier-Aggregated Multi-Antenna 4Ă—4 MIMO LTE-A Fronthaul by Spatial Multiplexing on Multicore Fiber. Journal of Lightwave Technology. 36(2):594-600. https://doi.org/10.1109/JLT.2017.2786582S59460036
Digital signal processing waveform aggregation and its experimental demonstration for next generation mobile fronthaul
L'abstract è presente nell'allegato / the abstract is in the attachmen
Millimetre-wave radio-over-fibre supported multi-antenna and multi-user transmission
In this thesis, various features of the RoF supported mmW communication for
future wireless systems have been analysed including photonic generation of mmW
for MIMO operation, performance analysis of mmW MIMO to achieve spatial
diversity and spatial multiplexing with analog RoF fronthaul, and multi-user
transmission in the 60 GHz-band using multiplexing-over-fibre transport and
frequency-selective antenna.
A low cost mmW generation system for two independent MIMO signals has been
presented, consisting of a single optical Phase Modulator (PM). The different
aspects of experimental analysis on RoF-supported mmW MIMO in this thesis,
which were not considered before, include use of specific MIMO algorithm to
understand the amount of improvement in coverage and data rate for a particular
MIMO technique, performance comparison with SISO at several user locations, and
verification of optimum RAU physical spacing for a particular transmission
distance with the theoretical results. The results show that flexible and wider RAU
spacings, required to obtain optimum performance in a mmW MIMO system, can
be achieved using the proposed analog RoF fronthaul. The investigation was
extended to verification of a method to individual measurement of mmW channel
coefficients and performing MIMO processing, which shows that mmW channels
are relatively static and analysis can be extended to much longer distances and
making projections for NĂ—N MIMO.
For mmW multi-user transmission, a novel low cost, low complexity system using
single RoF link and single RF chain with single transmitting antenna has been
presented and characterized, which was based on large number of RF chains and
multiple antenna units previously. The setup involves generation and RoF transport
of a composite SCM signal, upconversion at the RAU and transmission of different
frequency channels towards spatially distributed users using a frequency-selective
Leaky-Wave-Antenna (LWA), to convert Frequency Division Multiplexing (FDM)
in to Spatial Division Multiple Access (SDMA). Analysis on low user-signal
spacing for the SCM shows the feasibility to serve a large number of users within a
specific transmission bandwidth and experimental demonstration to achieve sum
rate of 10Gb/s is shown by serving 20 users simultaneously. Furthermore, investigation on SNR degradation of high bandwidth signals due to beamsteering
effect of the LWA and theoretical calculations of the sum data rate for different
number of users is performed, which shows that the proposed system can provide
much higher sum rates with high available SNR. It was also experimentally
demonstrated that improvement in coverage and spectral efficiency is obtained by
operating multiple LWAs using single RF chain. Finally, an experimental
demonstration of a DWDM-RoF based 60 GHz multi-user transmission using
single LWA is presented to show the feasibility to extend the setup for a multiple
RAU based system, serving each at distinct optical wavelength and performing
direct photonic upconversion at the RAU for low cost mmW generation
Advanced DSP Techniques for High-Capacity and Energy-Efficient Optical Fiber Communications
The rapid proliferation of the Internet has been driving communication networks closer and closer to their limits, while available bandwidth is disappearing due to an ever-increasing network load. Over the past decade, optical fiber communication technology has increased per fiber data rate from 10 Tb/s to exceeding 10 Pb/s. The major explosion came after the maturity of coherent detection and advanced digital signal processing (DSP). DSP has played a critical role in accommodating channel impairments mitigation, enabling advanced modulation formats for spectral efficiency transmission and realizing flexible bandwidth. This book aims to explore novel, advanced DSP techniques to enable multi-Tb/s/channel optical transmission to address pressing bandwidth and power-efficiency demands. It provides state-of-the-art advances and future perspectives of DSP as well
Optical Communication
Optical communication is very much useful in telecommunication systems, data processing and networking. It consists of a transmitter that encodes a message into an optical signal, a channel that carries the signal to its desired destination, and a receiver that reproduces the message from the received optical signal. It presents up to date results on communication systems, along with the explanations of their relevance, from leading researchers in this field. The chapters cover general concepts of optical communication, components, systems, networks, signal processing and MIMO systems. In recent years, optical components and other enhanced signal processing functions are also considered in depth for optical communications systems. The researcher has also concentrated on optical devices, networking, signal processing, and MIMO systems and other enhanced functions for optical communication. This book is targeted at research, development and design engineers from the teams in manufacturing industry, academia and telecommunication industries