Radio frequency optimization of a Global System for Mobile (GSM) network

Includes bibliographical references

Final report on the evaluation of RRM/CRRM algorithms

Deliverable public del projecte EVERESTThis deliverable provides a definition and a complete evaluation of the RRM/CRRM algorithms selected in D11 and D15, and evolved and refined on an iterative process. The evaluation will be carried out by means of simulations using the simulators provided at D07, and D14.Preprin

Discrete event simulation of wireless cellular networks

Postprint (published version

Design and Testing of a Mobile-Phone-Jammer

Dissimilar cellular-systems process signals differently, and yet, all cell-phone-networks use radio-signals that can be interrupted or, even, blocked, completely. This project highlights the design of a simple, low-cost mobile-phone-jammer and aims to present a solution for the problem of inappropriate-use of the cell-phones in restricted and prohibited-areas. The main concept of jamming is the releasing of signal (noise) of the same-frequency which is using by mobile-service-provider to overpower and destruct the user-signal. The fabrication of the jammer involved uncomplicated discrete components, resistors, capacitors, inductors and transistors to generate the required frequency (noise) and then amplifies the frequency generated to range of 800 MHZ to 1.4 GHZ in order to match the frequency of the mobile-phone being transmitted by the base-station. Relatively-satisfactory-jamming of a mobile-signal was confirmed by the blocking of the signals of the mobile-phones in 2G and 3G-networks (UMTS / WCDMA) operated via Safaricom, Airtell, Orange, and YU service-providers, when the phone indicated “no network”, thereby allowing no call to go through, with no-interference to other communication-means observed. Overall recommendation is that further and more deeper-research is needed to produce more-sophisticated and better jamming devices, as not to affect the other base-station-transmission-systems. Keywords: mobile, phone, jammer, design, signal

Design and characterization of downconversion mixers and the on-chip calibration techniques for monolithic direct conversion radio receivers

This thesis consists of eight publications and an overview of the research topic, which is also a summary of the work. The research described in this thesis is focused on the design of downconversion mixers and direct conversion radio receivers for UTRA/FDD WCDMA and GSM standards. The main interest of the work is in the 1-3 GHz frequency range and in the Silicon and Silicon-Germanium BiCMOS technologies. The RF front-end, and especially the mixer, limits the performance of direct conversion architecture. The most stringent problems are involved in the second-order distortion in mixers to which special attention has been given. The work introduces calibration techniques to overcome these problems. Some design considerations for front-end radio receivers are also given through a mixer-centric approach. The work summarizes the design of several downconversion mixers. Three of the implemented mixers are integrated as the downconversion stages of larger direct conversion receiver chips. One is realized together with the LNA as an RF front-end. Also, some stand-alone structures have been characterized. Two of the mixers that are integrated together with whole analog receivers include calibration structures to improve the second-order intermodulation rejection. A theoretical mismatch analysis of the second-order distortion in the mixers is also presented in this thesis. It gives a comprehensive illustration of the second-order distortion in mixers. It also gives the relationships between the dc-offsets and high IIP2. In addition, circuit and layout techniques to improve the LO-to-RF isolation are discussed. The presented work provides insight into how the mixer immunity against the second-order distortion can be improved. The implemented calibration structures show promising performance. On the basis of these results, several methods of detecting the distortion on-chip and the possibilities of integrating the automatic on-chip calibration procedures to produce a repeatable and well-predictable receiver IIP2 are presented.reviewe