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

A method performed by a network node (101) for enabling Interference Alignment, IA, of transmissions to user equipments (121-126) is provided. The network node (101) and the user equipments (121-126) are configured to be in a wireless telecommunications network (100). The network node receives signal strength values associated with more than one network node (101-107) for the user equipments (121-126), wherein each signal strength value is associated with one network node. Then, the network node schedules a first group (131) of the user equipments (121-126) on radio transmission resources that are orthogonal to radio transmission resources of at least one other group of the user equipments (121-126) when an IA gain value for each user equipment in the first group (131) passes a threshold level. The IA gain value is determined by the network node based on the received signal strength values. The network node may then enable IA of transmissions to the scheduled first group (131) of user equipments from at least two network nodes (101-103) capable of performing IA of transmissions. A network node (101) for enabling IA of transmissions to user equipments (121- 26) is also provided.

A network node and method for enabling interference alignment of transmissions to user equipments

The problem of designing simple and energy-efficient sensor nodes in a wireless sensor network is considered from a joint source-channel coding perspective. An algorithm for designing distributed scalar quantizers for orthogonal channels is proposed and evaluated. In particular the cases of the binary symmetric channel as well as the additive white Gaussian noise channel are studied. 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 quantization over noisy channels

Example embodiments presented herein are directed towards an eNodeB, and method therein, for generating downlink communications in a multiple antenna system. The method comprises transmitting, to a number of user equipments, a plurality of reference signals, where each signal is beamformed in a distinct direction within at least one correlated domain (e.g., elevation and/or azimuth). The eNodeB receives at least one CSI report from a specific user equipment and determines a primary reference signal based on, for example, the at least one CSI report. The eNodeB may thereafter generate downlink communication signals for antenna element(s) and/or subelements of the multiple antenna system. The downlink communication signals are beamformed into a transmitting direction that aligns most closely with a beamforming direction of the at least one primary reference signal, as compared to any other beamforming direction of the reference signals.

Node and method for generating beamformed for downlink communications

Embodiments herein relate to a method in a radio base station (12) for transforming a data transmission signal in a radio communications network. The radio base station (12) is connected to an active antenna array of a first number of active transmitting antennas, which each active transmitting antenna comprises sub elements. The radio base station (12) comprises a precoder codebook comprising precoders for transmitting signals in a diversified manner for a second number of antenna ports. The radio base station serves a user equipment in the radio communications network. The radio base station (12) precodes the data transmission signal with a precoder selected from the precoder codebook. The radio base station (12) furthermore transforms, linearly, the precoded data transmission signal by neutralizing a direction of the precoded data transmission signal and then directing the precoded data transmission signal vertically. The precoded data transmission signal is thereby enabled to be vertically adjusted towards the user equipment (10).

Radio base station and method therein for transforming a data transmission signal

The problem of designing simple and energy efficient nonlinear distributed source-channel codes is considered. By demonstrating similarities between this problem and the problem of bandwidth expansion, a structure for source-channel codes is presented and analyzed. Based on this analysis an understanding about desirable properties for such a system is gained and used to produce an explicit source-channel code which is then analyzed and simulated. One of the main advantages of the proposed scheme is that it is implementable for many sources, contrary to most existing nonlinear distributed source-channel coding systems.

Niklas Wernersson

Papers

A network node and method for enabling interference alignment of transmissions to user equipments

Distributed quantization over noisy channels

Node and method for generating beamformed for downlink communications

Radio base station and method therein for transforming a data transmission signal

Nonlinear coding and estimation for correlated data in wireless sensor networks