[...]... optimal power/performance trade-off is a key challenge The goal of this book is to provide flexibility solutions for analog circuits that allow baseband analog circuits to be part of an SDR front end architecture In more detail, there are two main features that need to be implemented: Performance reconfigurability This allows compatibility with a wide range of wireless standards In analog words, that... mobile handset The role of analog circuits is identified and a possible platform for the mobile terminal is proposed Chapter 2 investigates a number of architectural issues and trade-offs involved in the design of analog transceivers for a fully integrated multistandard SDR After commenting on the state of the art for SDR front end integrated circuits, a flexible zero-IF architecture for SDR is suggested,... terminals is to adopt the Software Defined Radio (SDR) approach with multiple-antenna (MIMO) 7 Basic Architecture For a 4G Terminal Access Point Quality of Experience Manager Multimedia - Multiformat CODEC Flexible Air Interface MODEM Analog Radio FRONT END Software Defined Radio Figure 1.4 IMEC Possible basic architecture of a 4G terminal, developed for the M4 program at techniques for bandwidths in excess... not to use analog circuits, but, instead, the problem is to add somehow several degrees of freedom to analog circuits so enabling the level of flexibility required by an SDR The idea is to make every analog block reconfigurable and to tune its performance by programming knobs by means of digital interfaces “Clean” analog designs are needed that are reconfigurable without giving in on actual performance,... reference architecture for the rest of this book, is described in detail To end the chapter, digital calibration techniques are shown that compensate for different analog imperfections in direct conversion transceivers D 2.1 The Software Radio Architecture Software Radio (SR) is a sophisticated radio that uses software to create highperformance, flexible communication devices performing digitally most... selection results in the best trade-off between the requirements for the polyphase filter and the ADC After A/D conversion the signal is digitally downconverted to baseband before digital filtering A digital mixer can then be used for the final downconversion to baseband where digital channel filtering is performed The migration of these traditionally analog functions into the digital domain offers significant... cannot afford Therefore, it is more accurate to say that the future of wireless semiconductors lies in continued optimization of tools, devices, architectures, software, and overall systems to meet the power, cost, performance, size, processing, and time-to-market requirements of 4G wireless devices In this context, analog signal processing is still necessary and, at the moment, using an analog front... have to be taken into account when the specifications for an SDR must be derived The optimal specifications distribution for minimum power consumption is given focusing on the baseband section Preface xiii Chapter 4 comments on the challenges that analog design for flexibility imposes to a designer and shows a possible way to tackle them Basic flexible analog building blocks are then analyzed from the flexibility... radio The RF and baseband building blocks should be reconfigurable in performances (channel bandwidth and center frequency, noise, gain, linearity, etc.) and power consumption More details on the possible options for implementing a SDR analog front end will be given in the following chapter Towards Cognitive Radios 11 SDR digital baseband engine Also in the design of reconfigurable digital baseband engines,... optimize the Quality of Experience for the user (QoE) 1.4 The Role of Analog Circuits The mobile terminal represents the real bottleneck to make the wireless centric world a reality The power/performance/price limitations on the mobile terminal force indeed trade-offs that a base station does not have and these limitations of handsets currently dictate inflexible networks While analog designers squeeze every .