DSP straddles wireless requirements News & Analysis 5/18/1999 Post a comment Success in the digital-signal-processor communications market comes down to a keen understanding of applications and system-level solutions. Designers need low-cost, high-performance DSPs designed for their specific markets. In the wireless communications market, the processing needs of the algorithms are well known, but cost, performance, size and power consumption place multidimensional constraints on system design.
Power design stresses efficiency News & Analysis 5/18/1999 Post a comment As the wireless revolution sweeps through the global marketplace, network operators need ever-more-efficient cellular technologies. Radio basestations (RBS) are a crucial element in any wireless network; to ensure maximum basestation performance and availability, operators are now deploying a new and more capable generation of RBS power-supply solutions.
LDMOS transistors rise to occasion News & Analysis 5/18/1999 Post a comment Today's market for mobile telephone systems puts tough requirements on the RF power transistors that are used in basestations. In the past, RF power amplifiers were designed to amplify single-carrier signals that transmitted the speech data of one user. AMPS and its European equivalent NMT used single-carrier power amplifiers. To increase capacity, basestation manufacturers simply used a combiner to merge multiple single-carrier amplifiers just before the antenna.
PWM generates 150 or 300 volts News & Analysis 5/18/1999 Post a comment Versions of this high-voltage generator circuit without programmable frequency have replaced variacs in motor-speed controllers and ATE equipment. Another version uses a step-down transformer for testing very high-current circuit breakers. This one generates 150 or 300 V, and 1.5 kW.
Software defines wireless radio News & Analysis 5/18/1999 Post a comment Advances in analog-to-digital converter technology have allowed designers of basestations to more seriously consider the implementation of a software-definable radio for cellular-transmission specifications.
Converters dance to software tune News & Analysis 5/18/1999 Post a comment Converging economic and technology drivers are influencing which architectures and components are used in the design of radio products for wireless basestations. Operators in new, growing markets such as Latin America and Asia, especially China, are depending on cost reductions in the existing digital cellular infrastructure to make services economically viable, while capacity limitations, especially in Japan,and wideband data services are fueling the drive toward third-generation (3G) deploymen
Building an effective wireless pipe News & Analysis 5/18/1999 Post a comment Wireless cellular services originally were driven by the need for wireless speech communication. However, we are seeing more data-based services taking a major role in our lives-paging, e-mail, Internet access, electronic commerce and others. Although some services traditionally have been offered only over wireline infrastructure, the high mobility of our society requires more and more wireless access to these services.
RF a stubborn challenge in cell-phone integration News & Analysis 5/18/1999 Post a comment In spite of the proliferation of microcell basestations, cellular handsets and their requirements still get all the attention and have all the glamour. Semiconductor makers are climbing all over one another to provide RF and baseband devices with high levels of integration and lower power consumption. And suppliers are competing ferociously to show how their devices will reduce the size and increase both the functionality and battery life of the next-generation handset.
A Book For All Reasons Bernard Cole1 Comment Robert Oshana's recent book "Software Engineering for Embedded Systems (Newnes/Elsevier)," written and edited with Mark Kraeling, is a 'book for all reasons.' At almost 1,200 pages, it ...