Position and Orientation Estimation through Millimeter Wave MIMO in 5G Systems

Millimeter wave signals and large antenna arrays are considered enabling technologies for future 5G networks. While their benefits for achieving high-data rate communications are well-known, their potential advantages for accurate positioning are largely undiscovered. We derive the Cram\'{e}r-Rao bound (CRB) on position and rotation angle estimation uncertainty from millimeter wave signals from a single transmitter, in the presence of scatterers. We also present a novel two-stage algorithm for position and rotation angle estimation that attains the CRB for average to high signal-to-noise ratio. The algorithm is based on multiple measurement vectors matching pursuit for coarse estimation, followed by a refinement stage based on the space-alternating generalized expectation maximization algorithm. We find that accurate position and rotation angle estimation is possible using signals from a single transmitter, in either line-of- sight, non-line-of-sight, or obstructed-line-of-sight conditions.Comment: The manuscript has been revised, and increased from 27 to 31 pages. Also, Fig.2, Fig. 10 and Table I are adde

On the Trade-off Between Accuracy and Delay in Cooperative UWB Navigation

In ultra-wide bandwidth (UWB) cooperative navigation, nodes estimate their position by means of shared information. Such sharing has a direct impact on the position accuracy and medium access control (MAC) delay, which needs to be considered when designing UWB navigation systems. We investigate the interplay between UWB position accuracy and MAC delay for cooperative scenarios. We quantify this relation through fundamental lower bounds on position accuracy and MAC delay for arbitrary finite networks. Results show that the traditional ways to increase accuracy (e.g., increasing the number of anchors or the transmission power) as well as inter-node cooperation may lead to large MAC delays. We evaluate one method to mitigate these delays

Cooperative localization with 802.15.4a CSS radios: Robustness to node failures

Cooperative positioning is a solution for location-aware applications where GPS-aided localization is unfeasible. In this paper, we provide a qualitative comparison between cooperative and non-cooperative localization under node-failure scenarios, in a typical indoor environment using off-the-shelf 802.15.4a radios. From our analysis, we observe the improved robustness and coverage offered by the cooperative approach in node-failure scenarios

On the Trade-Off Between Accuracy and Delay in Cooperative UWB Localization: Performance Bounds and Scaling Laws

Ultra-wide bandwidth (UWB) systems allow for accurate positioning in environments where global navigation satellite systems may fail, especially when complemented with cooperative processing. While cooperative UWB has led to centimeter-level accuracies, the communication overhead is often neglected. We quantify how accuracy and delay trade off in a wide variety of operation conditions. We also derive the asymptotic scaling of accuracy and delay, indicating that, in some conditions, standard cooperation offers the worst possible tradeoff. Both avenues lead to the same conclusion: indiscriminately targeting increased accuracy incurs a significant delay penalty. Simple countermeasures can be taken to reduce this penalty and obtain a meaningful accuracy/delay trade-off

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

Packet Reception Probabilities in Vehicular Communications Close to Intersections

Vehicular networks allow vehicles to share information and are expected to be an integral part of future intelligent transportation systems (ITS). To guide and validate the design process, analytical expressions of key performance metrics such as packet reception probabilities and throughput are necessary, in particular for accident-prone scenarios such as intersections. In this paper, we present a procedure to analytically determine the packet reception probability and throughput of a selected link, taking into account the relative increase in the number of vehicles (i.e., possible interferers) close to an intersection. We consider both slotted Aloha and CSMA/CA MAC protocols, and show how the procedure can be used to model different propagation environments of practical relevance. The procedure is validated for a selected set of case studies at low traffic densities

Positioning and Sensing in 6G: Gaps, Challenges, and Opportunities

Among the key differentiators of 6G compared to 5G will be the increased emphasis on radio-based positioning and sensing. These will be utilized not only for conventional location-aware services and for enhancing communication performance but also to support new use case families with extreme performance requirements. This article presents a unified vision from stakeholders across the value chain in terms of both opportunities and challenges for 6G positioning and sensing as well as use cases, performance requirements, and gap analysis. Combined, this motivates the technical advances in 6G and guides system design

Company ‘Emigration’ and EC Freedom of Establishment: Daily Mail Revisited

Following the ECJ’s recent case law on EC freedom of establishment (the Centros, Überseering and Inspire Art cases), regulatory competition for corporate law within the European Union takes place at an early stage of the incorporation of new companies. In contrast, as regards the ‘moving out’ of companies from the country of incorporation, the ECJ once considered a tax law restriction against the transfer abroad of a company’s administrative seat as compatible with EC freedom of establishment (the Daily Mail case). For years, this decision has been regarded as applicable to all restrictions imposed by countries of incorporation, even the forced liquidation of the ‘emigrating’ company. This paper addresses the question whether EC freedom of establishment really allows Member States to place any limit on the ‘emigration’ of nationally registered companies. It argues that EC freedom of establishment covers the transfer of the administrative seat as well as the transfer of the registered office and, therefore, that the country of incorporation cannot liquidate ‘emigrating’ companies. In addition, it addresses the question whether a new Directive is needed to allow the transfer of a com- pany’s registered office and the identity-preserving company law changes. It argues that such a Directive is necessary to avoid legal uncertainty and to protect the interests of employees, creditors and minority shareholders, among others, who could be detrimentally affected by the ‘emigration’ of national companies

Europeanization and the soft law process of EU corporate governance: how has the 2003 action plan impacted on national corporate governance codes?

This study explores Europeanization, the interrelationship between domestic and EU-level policy activity. Specifically, it asks how domestic policy is affected by EU-level (soft-law) policy processes. This contrasts with the hard-law focus of most Europeanization research. Our empirical analysis seeks to determine the extent to which the European Commission's 2003 plan to enhance corporate governance delivered on its aim of 'co-ordinating corporate governance efforts of member states'. This study thus differs from most others on convergence in corporate governance regimes, which look for evidence of convergence perse, rather than convergence towards a specified set of principles. Applying content analysis and econometric tests to 95 corporate governance codes issued between 1992 and mid-2010, we find that the Action Plan has influenced member states' corporate governance policies. However, the degree of national policy alignment to the Action Plan's priorities depends on when the corporate governance code was issued, here, and by whom

Factor graph based detection approach for high-mobility OFDM systems with large FFT modes

In this article, a novel detector design is proposed for orthogonal frequency division multiplexing (OFDM) systems over frequency selective and time varying channels. Namely, we focus on systems with large OFDM symbol lengths where design and complexity constraints have to be taken into account and many of the existing ICI reduction techniques can not be applied. We propose a factor graph (FG) based approach for maximum a posteriori (MAP) symbol detection which exploits the frequency diversity introduced by the ICI in the OFDM symbol. The proposed algorithm provides high diversity orders allowing to outperform the free-ICI performance in high-mobility scenarios with an inherent parallel structure suitable for large OFDM block sizes. The performance of the mentioned near-optimal detection strategy is analyzed over a general bit-interleaved coded modulation (BICM) system applying low-density parity-check (LDPC) codes. The inclusion of pilot symbols is also considered in order to analyze how they assist the detection process