1,581 research outputs found
Performance Analysis of a 5G Transceiver Implementation for Remote Areas Scenarios
The fifth generation of mobile communication networks will support a large
set of new services and applications. One important use case is the remote area
coverage for broadband Internet access. This use case ha significant social and
economic impact, since a considerable percentage of the global population
living in low populated area does not have Internet access and the
communication infrastructure in rural areas can be used to improve agribusiness
productivity. The aim of this paper is to analyze the performance of a 5G for
Remote Areas transceiver, implemented on field programmable gate array based
hardware for real-time processing. This transceiver employs the latest digital
communication techniques, such as generalized frequency division multiplexing
waveform combined with 2 by 2 multiple-input multiple-output diversity scheme
and polar channel coding. The performance of the prototype is evaluated
regarding its out-of-band emissions and bit error rate under AWGN channel.Comment: Presented in 2018 European Conference on Networks and Communications
(EuCNC),18-21 June, 2018, Ljubljana, Sloveni
Space-Time Signal Design for Multilevel Polar Coding in Slow Fading Broadcast Channels
Slow fading broadcast channels can model a wide range of applications in
wireless networks. Due to delay requirements and the unavailability of the
channel state information at the transmitter (CSIT), these channels for many
applications are non-ergodic. The appropriate measure for designing signals in
non-ergodic channels is the outage probability. In this paper, we provide a
method to optimize STBCs based on the outage probability at moderate SNRs.
Multilevel polar coded-modulation is a new class of coded-modulation techniques
that benefits from low complexity decoders and simple rate matching. In this
paper, we derive the outage optimality condition for multistage decoding and
propose a rule for determining component code rates. We also derive an upper
bound on the outage probability of STBCs for designing the
set-partitioning-based labelling. Finally, due to the optimality of the
outage-minimized STBCs for long codes, we introduce a novel method for the
joint optimization of short-to-moderate length polar codes and STBCs
A Survey of Physical Layer Security Techniques for 5G Wireless Networks and Challenges Ahead
Physical layer security which safeguards data confidentiality based on the
information-theoretic approaches has received significant research interest
recently. The key idea behind physical layer security is to utilize the
intrinsic randomness of the transmission channel to guarantee the security in
physical layer. The evolution towards 5G wireless communications poses new
challenges for physical layer security research. This paper provides a latest
survey of the physical layer security research on various promising 5G
technologies, including physical layer security coding, massive multiple-input
multiple-output, millimeter wave communications, heterogeneous networks,
non-orthogonal multiple access, full duplex technology, etc. Technical
challenges which remain unresolved at the time of writing are summarized and
the future trends of physical layer security in 5G and beyond are discussed.Comment: To appear in IEEE Journal on Selected Areas in Communication
Prediction of SINR using BER and EVM for Massive MIMO Applications
Future communication systems employing massive multiple input multiple output
will not have the ability to use channel state information at the mobile user
terminals. Instead, it will be necessary for such devices to evaluate the
downlink signal to interference and noise ratio (SINR) with interference both
from the base station serving other users within the same cell and other base
stations from adjacent cells. The SINR will act as an indicator of how well the
precoders have been applied at the base station. The results presented in this
paper from a 32 x 3 massive MIMO channel sounder measurement campaign at 2.4
GHz show how the received bit error rate and error vector magnitudes can be
used to obtain a prediction of both the average and dynamically changing SINR.Comment: 12th European Conference on Antennas and Propagatio
The Case for Combining a Large Low-Band Very High Frequency Transmitter With Multiple Receiving Arrays for Geospace Research: A Geospace Radar
We argue that combining a highâpower, largeâaperture radar transmitter with several largeâaperture receiving arrays to make a geospace radarâa radar capable of probing nearâEarth space from the upper troposphere through to the solar coronaâwould transform geospace research. We review the emergence of incoherent scatter radar in the 1960s as an agent that unified early, pioneering research in geospace in a common theoretical, experimental, and instrumental framework, and we suggest that a geospace radar would have a similar effect on future developments in space weather research. We then discuss recent developments in radioâarray technology that could be exploited in the development of a geospace radar with new or substantially improved capabilities compared to the radars in use presently. A number of applications for a geospace radar with the new and improved capabilities are reviewed including studies of meteor echoes, mesospheric and stratospheric turbulence, ionospheric flows, plasmaspheric and ionospheric irregularities, and reflection from the solar corona and coronal mass ejections. We conclude with a summary of technical requirements
Estimation of Sparse MIMO Channels with Common Support
We consider the problem of estimating sparse communication channels in the
MIMO context. In small to medium bandwidth communications, as in the current
standards for OFDM and CDMA communication systems (with bandwidth up to 20
MHz), such channels are individually sparse and at the same time share a common
support set. Since the underlying physical channels are inherently
continuous-time, we propose a parametric sparse estimation technique based on
finite rate of innovation (FRI) principles. Parametric estimation is especially
relevant to MIMO communications as it allows for a robust estimation and
concise description of the channels. The core of the algorithm is a
generalization of conventional spectral estimation methods to multiple input
signals with common support. We show the application of our technique for
channel estimation in OFDM (uniformly/contiguous DFT pilots) and CDMA downlink
(Walsh-Hadamard coded schemes). In the presence of additive white Gaussian
noise, theoretical lower bounds on the estimation of SCS channel parameters in
Rayleigh fading conditions are derived. Finally, an analytical spatial channel
model is derived, and simulations on this model in the OFDM setting show the
symbol error rate (SER) is reduced by a factor 2 (0 dB of SNR) to 5 (high SNR)
compared to standard non-parametric methods - e.g. lowpass interpolation.Comment: 12 pages / 7 figures. Submitted to IEEE Transactions on Communicatio
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