Angle-of-Arrival based localization using polynomial chaos expansions

International audienceIn this paper, polynomial chaos expansions are applied to angle-of-arrival based localization. By using a polynomial chaos expansion on a least squares estimator, a new positioning method is designed. Simulation results show that the proposed method returns precise information about the statistical distribution of the position

Performance of emerging multi-carrier waveforms for 5G asynchronous communications

This paper presents an extensive and fair comparison among the most promising waveform contenders for the 5G air interface. The considered waveform contenders, namely filter-bank multi-carrier (FBMC), universal-filtered multi-carrier (UFMC), generalized frequency-division multiplexing (GFDM) and resource-block filtered orthogonal frequency-division multiplexing (RB-F-OFDM) are compared to OFDM used in 4G in terms of spectral efficiency, numerical complexity, robustness towards multi-user interference (MUI) and resilience to power amplifier non-linearity. FBMC shows the best spectral containment and reveals to be almost insensitive to multi-user interference. It however suffers from its bad spectral efficiency for short bursts and from its poor multiple input multiple output (MIMO) compatibility. GFDM reveals to be the most promising contender, with the best spectral efficiency and the smallest complexity overhead compared to OFDM. It is also the most resilient to multi-user interference after FBMC and is MIMO compatible as soon as the interference can be managed. UFMC and RB-F-OFDM are finally the closest to OFDM and benefit therefore from a better compatibility with existing systems, even if their performance is generally lower than FBMC and GFDM.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Iterative RToF-based localization and time synchronization in WLAN-like systems

Iterative localization is currently arising as a solution to localize a Mobile Station (MS) in a cellular network. We recently showed that iterating between the conventional delay estimation and multi-lateration steps allows one to approach the performance of direct localization algorithms. Until now, the method has only been applied to the case of networks where the access points are perfectly synchronized with each other. In this letter, we present a localization and time synchronization iterative algorithm suitable for networks where access points are not synchronized. We show numerically that iterating between the two conventional steps brings a significant performance gain.info:eu-repo/semantics/publishe

Evolution of 5G networks: communications and positioning interplay

Invited talkinfo:eu-repo/semantics/nonPublishe

ToA-based iterative localization in rich multipath channels

Iterative localization is arising as a promising solution to determine the position of a mobile station in a cellular network. We recently showed that in a perfect line-of-sight environment, iterating between the conventional delay estimation and multi-lateration steps allows to approach the performance of the direct localization based on the observation of the received signals. In this paper we extend our iterative localization method to operate in rich multipath environments. Simulation results prove that given some prior knowledge on the power delay profile of the channel, the proposed iterative algorithm is robust to harsh propagation environments and performs very close to the direct localization approachinfo:eu-repo/semantics/publishe

Low complexity iterative localization of time-misaligned terminals in cellular networks

Recently, iterative localization has arisen as a promising approach to localize a Mobile Station (MS) in a cellular system. The conventional geo-location is obtained in a two-step approach: propagation delays are estimated and then the multi-lateration is responsible for the determination of the user position, based on the estimated delays. Iterative localization iterates between the two conventional steps to progressively refine delay estimates based on the position estimate available from the previous iterations. This localization scheme was seen to provide appealing performances compared to the two-step approach. It also seems to be computationally attractive with respect to direct localization that estimates the position using the digitized received signals directly. However, the iterative localization solution developed in literature relies on a strict time synchronization between MS and Base Stations (BSs). Moreover,the computational complexity of the iterative approach is not thoroughly compared to two-step and optimal solutions. This paper therefore proposes a new iterative localization method able to operate in a cellular system with time-misaligned terminals.We show by means of a detailed complexity analysis that the iterative positioning algorithm is one order of magnitude less complex than direct localization. Simulation results prove that the achievable performance after a few iterations approaches the performance of the direct localization solution.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Iterative ToA-based terminal positioning in emerging cellular systems

Emerging cellular networks integrate the user terminal geo-localization function besides the communication function. The conventional positioning approach is to estimate the terminal location in two-steps: first the distance to all connected base stations is assessed based on signal time-of-flight measurements, then the location is deduced from the distances by multilateration. The two-step approach incurs a performance degradation because information is lost from the received signal when the multi-lateration is performed. In this paper, we propose to iterate between the two conventional steps to progressively refine the distance estimates based on the knowledge of the position estimate obtained from the previous iterations. The information exchanged between the two-steps not only consists in the mean of the estimates (distance or position) but also of their variance that convey information about the reliability of the estimates. Simulation results show that the achievable performance after a few iterations is close to the performance of the optimal approach that directly estimates the position based on the observation of the received signal.info:eu-repo/semantics/publishe