Software for wireless broadband system design

The paper looks at the software of leading companies in the field of wireless broadband systems development. The basic characteristics of appropriate software and design systems are shown including the most typical examples for their implementation.

Reconfigurable Matching Networks for RF Amplifiers

This article presents applications of reconfigurable matching networks for RF amplifier design. Two possible solutions are given, one where the switching element is a PIN diode, and the other is based on graphene. Due to the fact that its conductivity depends on applied bias voltage, the graphene-based circuits can be used in microwave circuits as controllable elements. The structure of the proposed switch is very simple and it is particularly convenient for microstrip-based circuits. Because of that, a design of reconfigurable amplifier with the graphene-based switch is presented together with the one which has the PIN diode switch. Both amplifiers have the same specifications, and the one with the PIN diode switch is fabricated. The amplifier utilizing the PIN switch was used as a reference to make a comparison the two types of switches. Results of both amplifiers are very similar which indicates possible future applications of the graphene-based switch.

Joint Power Amplifiers and I/Q Modulator Impairments Modelling and Compensation for LTE Transmitters Using Artificial Neural Networks

This work introduces joint power amplifier (PA) and I/Q modulator modelling and compensation for LongTerm Evolution (LTE) transmitters using artificial neural networks (ANNs). The proposed solution util-izes a powerful nonlinear autoregressive with exogenous inputs (NARX) ANN architecture, which yieldsnoticeable results for high peak to average power ratio (PAPR) LTE signals. Given the ANNs learning capa-bilities, this one-step solution, which includes the mitigation of both PA nonlinearity and I/Q modulatorimpairments, is both accurate and adaptable

Short Film about War

A Short film about War is a narrative documentary artwork made entirely from information found on the worldwide web. In ten minutes this two screen gallery installation takes viewers around the world to a variety of war zones as seen through the collective eyes of the online photo sharing community Flickr, and as witnessed by a variety of existing military and civilian bloggers. As the ostensibly documentary 'film' plays itself out, a second screen logs the provenance of images, blog fragments and gps locations of each element comprising the work, so that the same information is simultaneously communicated to the viewer in two parallel formats -on one hand as a dramatised reportage and on the other hand as a text log. In offerring this tautology, we are attempting to explore and reveal the way in which information changes as it is gathered, edited and then mediated through networked communications technologies or broadcast media, and how that changes and distorts meaning -especially for (the generally wealthy minority of) the world's users of high speed broadband networks, who have become used to the treacherously persuasive panoptic view that google earth (and the worldwide web) appears to give us.

Evaluation of nonlinear distortion in MIMO transmitters

In this paper, an evaluation of unwanted effects in Multiple Input Multiple Output (MIMO) transmitters is described. Complete 2×2 and 4×4 MIMO Orthogonal Frequency Division Multiplex (OFDM) transmitters are simulated for the purpose of quantifying all potential unwanted effects such as Power Amplifiers' (PAs) nonlinearity, linear and nonlinear crosstalk, and IQ modulator imperfections. An experimental analysis of a 2×2 MIMO transmitter using two-tones and WCDMA signal is presented.