Baseband analog front-end and digital back-end for reconfigurable multi-standard terminals

Multimedia applications are driving wireless network operators to add high-speed data services such as Edge (E-GPRS), WCDMA (UMTS) and WLAN (IEEE 802.11a,b,g) to the existing GSM network. This creates the need for multi-mode cellular handsets that support a wide range of communication standards, each with a different RF frequency, signal bandwidth, modulation scheme etc. This in turn generates several design challenges for the analog and digital building blocks of the physical layer. In addition to the above-mentioned protocols, mobile devices often include Bluetooth, GPS, FM-radio and TV services that can work concurrently with data and voice communication. Multi-mode, multi-band, and multi-standard mobile terminals must satisfy all these different requirements. Sharing and/or switching transceiver building blocks in these handsets is mandatory in order to extend battery life and/or reduce cost. Only adaptive circuits that are able to reconfigure themselves within the handover time can meet the design requirements of a single receiver or transmitter covering all the different standards while ensuring seamless inter-interoperability. This paper presents analog and digital base-band circuits that are able to support GSM (with Edge), WCDMA (UMTS), WLAN and Bluetooth using reconfigurable building blocks. The blocks can trade off power consumption for performance on the fly, depending on the standard to be supported and the required QoS (Quality of Service) leve

A Multiproject Chip Approach to the Teaching of Analog MOS LSI and VLSI

Multiproject chip implementation has been used in teaching analog MOS circuit design. After having worked with computer simulation and layout aids in homework problems, students designed novel circuits including several high performance op amps, an A/D converter, a switched capacitor filter, a 1 K dynamic RAM, and a variety of less conventional MOS circuits such as a VII converter, an AC/DC converter, an AM radio receiver, a digitally-controlled analog signal processor, and on-chip circuitry for measuring transistor capacitances. These circuits were laid out as part of an NMOS multiproject chip. Several of the designs exhibit a considerable degree of innovation; fabrication pending, computer simulation shows that some may be pushing the state of the art. Several designs are of interest to digital designers; in fact, the course has provided knowledge and technique needed for detailed digital circuit design at the gate level

Energy-efficiency improvements for optical access

This article discusses novel approaches to improve energy efficiency of different optical access technologies, including time division multiplexing passive optical network (TDM-PON), time and wavelength division multiplexing PON (TWDM-PON), point-to-point (PTP) access network, wavelength division multiplexing PON (WDM-PON), and orthogonal frequency division multiple access PON (OFDMA-PON). These approaches include cyclic sleep mode, energy-efficient bit interleaving protocol, power reduction at component level, or frequency band selection. Depending on the target optical access technology, one or a combination of different approaches can be applied

Free Level Threshold Zone (FLTZ) Logic For Mixed Analog-Digital Closed Loop Circuitry [TK7887.6. N335 2008 f rb].

Para penyelidik sentiasa mencari cara-cara penambahbaikan kaedah antara muka antara domain Analog dan Digital. Researchers have always look for ways to improve the interfacing method between the Analog and Digital domain

FPGAs in Industrial Control Applications

The aim of this paper is to review the state-of-the-art of Field Programmable Gate Array (FPGA) technologies and their contribution to industrial control applications. Authors start by addressing various research fields which can exploit the advantages of FPGAs. The features of these devices are then presented, followed by their corresponding design tools. To illustrate the benefits of using FPGAs in the case of complex control applications, a sensorless motor controller has been treated. This controller is based on the Extended Kalman Filter. Its development has been made according to a dedicated design methodology, which is also discussed. The use of FPGAs to implement artificial intelligence-based industrial controllers is then briefly reviewed. The final section presents two short case studies of Neural Network control systems designs targeting FPGAs

Software Defined Radio Equipment: What's the Best Design Approach to Reduce Power Consumption and Increase Reconfigurability ?

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