Multirate cascaded discrete-time low-pass ΔΣ modulator for GSM/Bluetooth/UMTS

This paper shows that multirate processing in a cascaded discrete-time ΔΣ modulator allows to reduce the power consumption by up to 35%. Multirate processing is possible in a discrete-time ΔΣ modulator by its adaptibility with the sampling frequency. The power reduction can be achieved by relaxing the sampling speed of the first stage and increasing it appropriately in the second stage. Furthermore, a cascaded ΔΣ modulator enables the power efficient implementation of multiple communication standards.@The advantages of multirate cascaded ΔΣ modulators are demonstrated by comparing the performance of single-rate and multirate implementations using behavioral-level and circuit-level simulations. This analysis has been further validated with the design of a multirate cascaded triple-mode discrete-time ΔΣ modulator. A 2-1 multirate low-pass cascade, with a sampling frequency of 80 MHz in the first stage and 320 MHz in the second stage, meets the requirements for UMTS. The first stage alone is suitable for digitizing Bluetooth and GSM with a sampling frequency of 90 and 50 MHz respectively. This multimode ΔΣ modulator is implemented in a 1.2 V 90 nm CMOS technology with a core area of 0.076 mm2. Measurement results show a dynamic range of 66/77/85 dB for UMTS/ Bluetooth/GSM with a power consumption of 6.8/3.7/3.4 mW. This results in an energy per conversion step of 1.2/0.74/2.86 pJ

A novel low-voltage reconfigurable ΣΔ modulator for 4G wireless receivers

This paper presents a new adaptable cascade ΣΔ modulator architecture fo r low-voltage multi-stan- dard applications. It uses two reconfiguration strategies: a programmable global resonation and a variable loop-filter order. These techniques are properly com- bined in a novel topology that allows to increase the effec- tive resolution in a given bandwidth, whereas keeping relaxed output swing requirements and high robustness to mismatch and to non-linearities of the amplifiers. Time-domain simulations incl uding the main circuit-level non-idealities are shown to demonstrate the benefits of the presented modulator when it is configured to cope with the requirements of GSM, UMTS, WLAN and Wi-Max.España, Ministerio de Educación y Ciencia TEC2007-67247-C02-01/MICEspaña, Ministerio de Innovación, Ciencia y Empresa, Junta de Andalucía TIC-253

Identidade profissional e identidade pessoal dos/as professores/as surdos/as de LGP: em busca da cidadania

O objetivo central desta dissertação, faz-se na compreensão da trajetória de construçãoidentitária do/a professor/a surdo/a de LGP em consonância com a de ser surdo/a. Portanto,parte-se do conceito de identidade apresentado por Dubar, sendo esta resultado do processode socialização, assim, a identidade constrói-se a partir dos processos relacionais ebiográficos. Logo, analisamos as narrativas de sete professores/as surdos/as de LGP - um/ade cada nível escolar, do/a educador/a de infância ao professor universitário. Neste sentido,abordamos questões sobre a identidade profissional do/a professor/a, os caminhos paralegitimar a profissão de professor/a de língua gestual portuguesa e as suas conquistas pelosdireitos a sua cidadania plena. Portanto, esta pesquisa aponta a entrada destes/as surdos/asna comunidade surda, a partir do seu ingresso na escola para surdos/as, pois assim iniciam-se no processo de compreensão do modo de estar, pertencer, sentir e ser membro de umacomunidade, com características linguísticas e culturais específicas. Todos/as os/assurdos/as apresentam uma viragem na vida escolar a partir da sua entrada para escola desurdos/as, ou seja, explicam a melhora na sua qualidade de vida, na sua autoestima e na suaautonomia a partir do contacto surdo/a-surdo/a. A partir das narrativas surdas,compreendemos sobretudo a cultura de trabalho inserida no corpo docente - pedagogia surda,metodologia visual, currículo surdo - bem como a importância para o indivíduo surdoaprender a língua gestual, a sua língua natural, pois é através do seu uso que o/a surdo/a temacesso à comunidade e cultura surdas. Portanto, destaca-se a importância da aquisição deLG para que o/a surdo/a possa tornar-se um/a surdo/a cidadão/ã. Contudo, a legislação queestá em vigor em Portugal, não esta de acordo com uma educação bilingue para surdos/as.O Decreto-Lei 54/2018 preconiza um modelo de inclusão que prevê que todas as criançaspossam ter respostas adequadas às suas singularidades na escola que frequentam, seja elaqual for, o que corrobora para o esvaziamento dos/as surdos/as em EREBAS, tendo em vistaque as famílias optem pelas escolas próximas da sua residência. Portanto, este novo decretonão respeita a singularidade cultural e linguística do/a surdo/a e corrobora que os/assurdos/as se isolem da sua cultura e da sua comunidade surda

A SIMULINK Block Set for the High-Level Simulation of Multistandard Radio Receivers

This paper describes a SIMULINK block set for the behavioral simulation of RF receivers. Building blocks are modeled including their main circuit-level non idealities. These models are incorporated into the SIMULINK environment making an extensive use of C-coded S-functions and reducing the number of library block elements. This approach reduces the simulation time while keeping high accuracy, what makes the proposed toolbox very appropriate to be combined with an optimizer for the automated high-level synthesis of radio receivers. As a case study, a direct-conversion receiver intended for 4G telecom systems is modeled and simulated using the proposed toolbox.This work has been supported by the Spanish Ministry of Science and Education (with support from the European Regional Development Fund) under contract TEC2004-01752/MIC.Peer reviewe

A novel low-voltage reconfigurable ΣΔ modulator for 4G wireless receivers

Trabajo presentado al 23rd DCIS celebrado en Grenoble (Francia) del 12 al 14 de noviembre de 2008.This paper presents a new adaptable cascade ΣΔ modulator architecture for low-voltage multi-standard applications. It uses two reconfiguration strategies: a programmable global resonation and a variable loop-filter order. These techniques are properly combined in a novel topology that allows to increase the effective resolution in a given bandwidth, whereas keeping relaxed output swing requirements and high robustness to mismatch and to non-linearities of the amplifiers. Time-domain simulations including the main circuit-level non-idealities are shown to demonstrate the benefits of the presented modulator when it is configured to cope with the requirements of GSM, UMTS, WLAN and Wi-Max.This work has been supported by the Spanish Ministry of Science and Education (with support from the European Regional Development Fund) under contract TEC2007-67247-C02-01/MIC and the Andalusian (Regional) Ministry of Innovation, Science and Enterprise under contract TIC-2532.Peer Reviewe

Solución de conflictos por compartición de aguas con Teoría de Juegos

En este trabajo estudiamos el uso de recursos naturales del río Yangtsé: la navegación, el agua como bien de consumo, la energía hidráulica y los sedimentos para su conversión a fertilizantes. Este estudio trata de asignar los costes de diversos agentes que usan estos recursos de manera proporcional. Hemos tenido en cuenta el régimen político del país por el que discurre el río asumiendo que la reducción de costes se equipara con el control de la polución por parte sobre todo de las empresas. Hemos usado técnicas de juegos no cooperativos para su resolución.In this project we have studied the natural resources uses of Yangtze river: sailing, water as household good, hydraulic energy and sediments for conversion to fertilizers. This study wants to assign proportionally some agent costs who uses those resources. We have kept political regime of the country where the river flows in mind, assuming reduction od costs is equated with the control of the pollution on the part of the companies. We have used non-cooperative game techniques for resolution.Universidad de Sevilla. Grado en Ingeniería de las Tecnologías Industriale

Design of a power-efficient widely-programmable Gm-LC band-pass sigma-delta modulator for SDR

This paper presents the design and implementation of a fourth-order band-pass continuous-time modulator intended for the digitization of radio-frequency signals in softwaredefined- radio applications. The modulator architecture consists of two Gm-LC resonators with a tunable notch frequency and a 4-bit flash analog-to-digital converter in the forward path and a non-return-to-zero digital-to-analog converter with a finiteimpulse- response filter in the feedback path. Both system-level and circuit-level reconfiguration techniques are included in order to allow the modulator to digitize signals placed at different carrier frequencies, from 450MHz to 950MHz. A proper synthesis methodology of the loop-filter coefficients at system level and the use of inverter-based switchable transconductors allow to optimize the performance in terms of robustness to circuit errors, stability and power consumption. The circuit, implemented in 65- nm CMOS, can digitise signals with up to 57-dB SNDR within a 40-MHz bandwidth, with an adaptive power dissipation of 16.7- to-22.8 mW and a programmable 1.2/2GHz clock rate1

Espacios funcionales para el servicio de atención integral en los centros de protección de niños y adolescentes, Huanchaco 2020

En este trabajo de investigación tiene como objetivo general determinar cómo influyen los espacios funcionales para desarrollar un servicio de atención integral en los centros de protección de niños y adolescentes, Huanchaco en la cual los niños de los centros de protección contaran con espacios óptimos brindándole un tratamiento integral que cubrirá la atención psicológica y las áreas de trabajo donde el menor tenga una mejor calidad de vida. El tipo de investigación es básica no experimental, de enfoque mixto, donde se utilizarán como instrumentos de recolección de datos, las fichas de registro de información, guía de entrevista, cuestionario, dando como resultado la necesidad de intervenir el albergue y sus espacios para una mejor calidad de atención.Al final se logró concluir que en esta investigación Se demostró, que la influencia de los espacios funcionales en menores de edad, influye significativamente, en los servicios de atención integral de los espacios funcionales influye para desarrollar de un servicio de atención integral. para una mejor recuperación y tratamiento del menor

Resonation-based hybrid continuous-time/discrete-time cascade ΣΔ modulators: application to 4G wireless telecom

This paper presents innovative architectures of hybrid Continuous-Time/Discrete-Time (CT/DT) cascade ΣΔ Modulators (ΣΔMs) made up of a front-end CT stage and a back-end DT stage. In addition to increasing the digitized signal bandwidth as compared to conventional ΣΔMs, the proposed topologies take advantage of the CT nature of the front-end ΣΔM stage, by embedding anti-aliasing filtering as well as their suitability to operate up to the GHz range. Moreover, the presented modulators include multi-bit quantization and Unity Signal Transfer Function (USTF) in both stages to reduce the integrator output swings, and programmable resonation to optimally distribute the zeroes of the overall Noise Transfer Function (NTF), such that the in-band quantization noise is minimized for each operation mode. Both local and inter-stage (global) based resonation architectures are synthesized and compared in terms of their circuit complexity, resolution-bandwidth programmability and robustness with respect to circuit non-ideal effects. The combination of all mentioned characteristics results in novel hybrid ΣΔMs, very suited for the implementation of adaptive/reconfigurable Analog-to-Digital Converters (ADCs) intended for the 4th Generation (4G) of wireless telecom systems

Design of a 130-nm CMOS Reconfigurable Cascade ΣΔ Modulator for GSM/UMTS/Bluetooth

This paper reports a 130-nm CMOS programmable cascade ΣΔ modulator for multistandard wireless terminals, covering three standards: GSM, Bluetooth and UMTS. The modulator is reconfigured at both architecture- and circuitlevel in order to adapt its performance to the different standard specifications with optimized power consumption. The design of the building blocks is based upon a top-down CAD methodology that combines simulation and statistical optimization at different levels of the system hierarchy. Transistor-level simulations show correct operation for all standards, featuring 13-bit, 11.3-bit and 9-bit effective resolution within 200-kHz, 1-MHz and 4-MHz bandwidth, respectively.España, Ministerio de Educación y Ciencia TEC2004-01752/MI