30 research outputs found
Joint Localization and Mapping through Millimeter Wave MIMO in 5G Systems
Millimeter wave signals with multiple transmit and receive antennas are considered as enabling technology for enhanced mobile broadband services in 5G systems. While this combination is mainly associated with achieving high data rates, it also offers huge potential for radio-based positioning. Recent studies showed that millimeter wave signals with multiple transmit and receive antennas are capable of jointly estimating the position and orientation of a mobile terminal while mapping the radio environment simultaneously. To this end, we present a message passing-based estimator which jointly estimates the position and orientation of the mobile terminal, as well as the location of reflectors or scatterers in the absence of the line-of-sight path. We provide numerical examples showing that our estimator can provide considerably higher estimation accuracy compared to a state-of-the-art estimator. Our examples demonstrate that our message passing-based estimator neither requires the presence of a line-of-sight path nor prior knowledge regarding any of the parameters to be estimated
Joint Localization and Mapping through Millimeter Wave MIMO in 5G Systems - Extended Version
Millimeter wave signals with multiple transmit and receive antennas are
considered as enabling technology for enhanced mobile broadband services in 5G
systems. While this combination is mainly associated with achieving high data
rates, it also offers huge potential for radio-based positioning. Recent
studies showed that millimeter wave systems with multiple transmit and receive
antennas are capable of jointly estimating the position and orientation of a
mobile terminal while mapping the radio environment simultaneously. To this
end, we present a message passing-based estimator which jointly estimates the
position and orientation of the mobile terminal, as well as the location of
reflectors or scatterers. We provide numerical examples showing that this
estimator can provide considerably higher estimation accuracy compared to a
state-of-the-art estimator. Our examples demonstrate that our message
passing-based estimator neither requires the presence of a line-of-sight path
nor prior knowledge regarding any of the parameters to be estimated
Wireless Localization for mmWave Networks in Urban Environments
Millimeter wave (mmWave) technology is expected to be a major component of 5G
wireless networks. Ultra-wide bandwidths of mmWave signals and the possibility
of utilizing large number of antennas at the transmitter and the receiver allow
accurate identification of multipath components in temporal and angular
domains, making mmWave systems advantageous for localization applications. In
this paper, we analyze the performance of a two-step mmWave localization
approach that can utilize time-of-arrival, angle-of-arrival, and
angle-of-departure from multiple nodes in an urban environment with both
line-of-sight (LOS) and non-LOS (NLOS) links. Networks with/without
radio-environmental mapping (REM) are considered, where a network with REM is
able to localize nearby scatterers. Estimation of a UE location is challenging
due to large numbers of local optima in the likelihood function. To address
this problem, a gradient-assisted particle filter (GAPF) estimator is proposed
to accurately estimate a user equipment (UE) location as well as the locations
of nearby scatterers. Monte Carlo simulations show that the GAPF estimator
performance matches the Cramer-Rao bound (CRB). The estimator is also used to
create an REM. It is seen that significant localization gains can be achieved
by increasing beam directionality or by utilizing REM
Harnessing NLOS Components for Position and Orientation Estimation in 5G Millimeter Wave MIMO
In the past, NLOS propagation was proven to be a source of distortion for radio-based positioning systems due to the lack of temporal and spatial resolution of previous cellular systems. Hence, every NLOS component was perceived as a perturbation for localization. Even though 5G is not yet standardized, a strong proposal, which has the potential to overcome the problem of limited temporal and spatial resolution, is the massive MIMO millimeter wave technology. We reconsider the role of NLOS components for position and orientation estimation in 5G millimeter wave MIMO systems. Our analysis is based on the concept of Fisher information. We show that for sufficiently high temporal and spatial resolution, NLOS components always provide position and orientation information that consequently increase position and orientation estimation accuracy. In addition, we show that the information gain of NLOS components depends on the actual location of the reflector or scatter. Our numerical examples suggest that the NLOS components are most informative about the position and orientation of a mobile terminal when the corresponding reflectors or scatterers are illuminated with narrow beams
Clock and Orientation-Robust Simultaneous Radio Localization and Mapping at Millimeter Wave Bands
This paper proposes a radio simultaneous location and mapping (radio-SLAM)
scheme based on sparse multipath channel estimation. By leveraging sparse
channel estimation schemes at millimeter wave bands, namely high resolution
estimates of the multipath angle of arrival (AoA), time difference of arrival
(TDoA), and angle of departure (AoD), we develop a radio-SLAM algorithm that
operates without any requirements of clock synchronization, receiver
orientation knowledge, multiple anchor points, or two-way protocols. Thanks to
the AoD information obtained via compressed sensing (CS) of the channel, the
proposed scheme can estimate the receiver clock offset and orientation from a
single anchor transmission, achieving sub-meter accuracy in a realistic typical
channel simulation.Comment: This is the author's pre-print version of a paper accepted for
presentation in IEEE WCNC 2023, Glasgow, Scotlan