4,331 research outputs found
Multi-Array 5G V2V Relative Positioning: Performance Bounds
We study the performance bounds of vehicle-to-vehicle (V2V) relative
positioning for vehicles with multiple antenna arrays. The Cram\'{e}r-Rao bound
for the estimation of the relative position and the orientation of the Tx
vehicle is derived, when angle of arrival (AOA) measurements with or without
time-difference of arrival (TDOA) measurements are used. In addition,
geometrically intuitive expressions for the corresponding Fisher information
are provided. The derived bounds are numerically evaluated for different
carrier frequencies, bandwidths and array configurations under different V2V
scenarios, i.e. overtaking and platooning. The significance of the AOA and TDOA
measurements for position estimation is investigated. The achievable
positioning accuracy is then compared with the present requirements of the 3rd
Generation Partnership Project (3GPP) 5G New Radio (NR) vehicle-to-everything
(V2X) standardization
Massive MIMO is a Reality -- What is Next? Five Promising Research Directions for Antenna Arrays
Massive MIMO (multiple-input multiple-output) is no longer a "wild" or
"promising" concept for future cellular networks - in 2018 it became a reality.
Base stations (BSs) with 64 fully digital transceiver chains were commercially
deployed in several countries, the key ingredients of Massive MIMO have made it
into the 5G standard, the signal processing methods required to achieve
unprecedented spectral efficiency have been developed, and the limitation due
to pilot contamination has been resolved. Even the development of fully digital
Massive MIMO arrays for mmWave frequencies - once viewed prohibitively
complicated and costly - is well underway. In a few years, Massive MIMO with
fully digital transceivers will be a mainstream feature at both sub-6 GHz and
mmWave frequencies. In this paper, we explain how the first chapter of the
Massive MIMO research saga has come to an end, while the story has just begun.
The coming wide-scale deployment of BSs with massive antenna arrays opens the
door to a brand new world where spatial processing capabilities are
omnipresent. In addition to mobile broadband services, the antennas can be used
for other communication applications, such as low-power machine-type or
ultra-reliable communications, as well as non-communication applications such
as radar, sensing and positioning. We outline five new Massive MIMO related
research directions: Extremely large aperture arrays, Holographic Massive MIMO,
Six-dimensional positioning, Large-scale MIMO radar, and Intelligent Massive
MIMO.Comment: 20 pages, 9 figures, submitted to Digital Signal Processin
Millimeter-wave Mobile Sensing and Environment Mapping: Models, Algorithms and Validation
Integrating efficient connectivity, positioning and sensing functionalities
into 5G New Radio (NR) and beyond mobile cellular systems is one timely
research paradigm, especially at mm-wave and sub-THz bands. In this article, we
address the radio-based sensing and environment mapping prospect with specific
emphasis on the user equipment (UE) side. We first describe an efficient
l1-regularized least-squares (LS) approach to obtain sparse range--angle charts
at individual measurement or sensing locations. For the subsequent environment
mapping, we then introduce a novel state model for mapping diffuse and specular
scattering, which allows efficient tracking of individual scatterers over time
using interacting multiple model (IMM) extended Kalman filter and smoother. We
provide extensive numerical indoor mapping results at the 28~GHz band deploying
OFDM-based 5G NR uplink waveform with 400~MHz channel bandwidth, covering both
accurate ray-tracing based as well as actual RF measurement results. The
results illustrate the superiority of the dynamic tracking-based solutions,
compared to static reference methods, while overall demonstrate the excellent
prospects of radio-based mobile environment sensing and mapping in future
mm-wave networks
The 5G Localisation Waveform
Todays cellular networks have distinct services that
come with different requirements, figures of merit, etc. for each
application. A communication service such as voice communication
relies on latency better than 150 ms and bit error rates
lower than 1
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