Zeros of orthogonal polynomials

Wireless sensor networks (WSNs) enable new applications and require non-conventional paradigms for protocol design due to several constraints. Owing to the requirement for low device complexity together with low energy consumption (i.e., long network lifetime), a proper balance between communication and signal/data processing capabilities must be found. This motivates a huge effort in research activities, standardization process, and industrial investments on this field since the last decade. This survey paper aims at reporting an overview of WSNs technologies, main applications and standards, features in WSNs design, and evolutions. In particular, some peculiar applications, such as those based on environmental monitoring, are discussed and design strategies highlighted; a case study based on a real implementation is also reported. Trends and possible evolutions are traced. Emphasis is given to the IEEE 802.15.4 technology, which enables many applications of WSNs. Some example of performance characteristics of 802.15.4-based networks are shown and discussed as a function of the size of the WSN and the data type to be exchanged among nodes.

https://www.mdpi.com/1424-8220/9/9/6869/pdf

An Overview on Wireless Sensor Networks Technology and Evolution

Digital coding of waveforms: Principles and applications to speech and video

Aspects of the subject disclosure may include, for example, receiving, by a feed point of a dielectric antenna, electromagnetic waves from a dielectric core coupled to the feed point without an electrical return path, where at least a portion of the dielectric antenna comprises a conductive surface, directing, by the feed point, the electromagnetic waves to a proximal portion of the dielectric antenna, and radiating, via an aperture of the dielectric antenna, a wireless signal responsive to the electromagnetic waves being received at the aperture. Other embodiments are disclosed.

Method and apparatus for coupling an antenna to a device

A distributed antenna and backhaul system provide network connectivity for a small cell deployment. Rather than building new structures, and installing additional fiber and cable, embodiments described herein disclose using high-bandwidth, millimeter-wave communications and existing power line infrastructure. Above ground backhaul connections via power lines and line-of-sight millimeter-wave band signals as well as underground backhaul connections via buried electrical conduits can provide connectivity to the distributed base stations. An overhead millimeter-wave system can also be used to provide backhaul connectivity. Modules can be placed onto existing infrastructure, such as streetlights and utility poles, and the modules can contain base stations and antennas to transmit the millimeter-waves to and from other modules.

Backhaul link for distributed antenna system

Sensor nodes in wireless sensor networks should preferable be both cheap and energy efficient. To cope with these requirements an algorithm for designing distributed scalar quantizers optimized for noisy channels is proposed and evaluated. Applying the algorithm results in locally optimal systems. It is demonstrated that the correlation between the sources can be used to reduce the quantization distortion when the channel is close to error-free. If, on the other hand, there are a lot of disturbances on the channel the correlation can be used to introduce protection against channel errors.

Distributed Scalar Quantizers for Noisy Channels

Some of the example embodiments presented herein are directed towards an eNodeB (401), and corresponding method therein, for establishing beamforming for downlink communications in a multiple antenna system. The eNodeB (401) may be configured to transmit a plurality of reference signals, where each reference signal is beamformed into a distinct direction with in at least one correlated domain (e.g., an elevation and/or azimuth domain). The eNodeB (401) may thereafter generate beamformed downlink communications for antenna elements and/or subelements based on received signal quality assessments of the plurality of reference signals. Some example embodiments may be directed towards a user equipment (505), and corresponding methods therein, for establishing beamforming for downlink communications. The user equipment (505) may be configured to receive the plurality of reference signals and provide signal assessments of the reference signals based on measurements performed by the user equipment (505). The user equipment (505) may thereafter transmit the signal quality assessments to the eNodeB (401) and receive beamformed downlink communications based on the signal quality assessments.

Beamformed downlink communications for a multiple antenna system

The problem of designing simple and energy efficient sensor nodes for a wireless sensor network is considered in a joint source-channel coding perspective. An algorithm for designing distributed scalar quantizers optimized for orthogonal additive white Gaussian noise channels is proposed and evaluated. It is demonstrated that correlation between sources can be useful in order to reduce quantization distortion as well as protecting data when being transmitted over non-ideal channels. It is also demonstrated that the obtained system is robust against channel SNR mismatch.

Distributed Scalar Quantizers for Gaussian Channels

A method in a network node(800) for selecting a beam candidate (A,B,C) in a wireless communication network, comprising acquiring(900) information comprising information indicative of signal qualities for a plurality of beam candidates;, assigning (910) to each of the plurality of beam candidates a factor indicating signal interference generated by the corresponding beam candidate and selecting (920) and selecting a beam candidate taking into account at least said associated signal quality and the factor assigned to the selected beam candidate. The present technology is also related to a method in a UE (700); a network node (800) and a UE (700).

Method in network node, method in user equipment, network node and user equipment for selecting beam candidate

A scenario of distributed sensing for networked control systems is considered and a new approach to distributed sensing and transmission is presented. The state process of a scalar first order linear time invariant dynamical system is sensed by a network of wireless sensors, which then instantaneously transmit their measurements to a remotely situated control unit over parallel Gaussian channels. The control unit aims to stabilize the system in mean square sense. The proposed non-linear delay-free sensing and transmission strategy is compared with the well-known amplify-and-forward strategy, using the LQG control cost as a figure of merit. It is demonstrated that the proposed nonlinear scheme outperforms the best linear scheme even when there are only two sensors in the network. The proposed sensing and transmission scheme can be implemented with a reasonable complexity and it is shown to be robust to the uncertainties in the knowledge of the sensors about the statistics of the measurement noise and the channel noise.

/pdf/nonlinear-distributed-sensing-for-closed-loop-control-over-2g8w1o9vd8.pdf

Niklas Wernersson

Papers

Distributed Scalar Quantizers for Noisy Channels

Beamformed downlink communications for a multiple antenna system

Distributed Scalar Quantizers for Gaussian Channels

Method in network node, method in user equipment, network node and user equipment for selecting beam candidate

Nonlinear distributed sensing for closed-loop control over Gaussian channels