Signal processing for wireless transceivers

Abstract The data rates as well as quality of service (QoS) requirements for rich user experience in wireless communication services are continuously growing. While consuming a major portion of the energy needed by wireless devices, the wireless transceivers have a key role in guaranteeing the needed data rates with high bandwidth efficiency. The cost of wireless devices also heavily depends on the transmitter and receiver technologies. In this chapter, we concentrate on the problem of transmitting information sequences efficiently through a wireless channel and performing reception such that it can be implemented with state of the art signal processing tools. The operations of the wireless devices can be divided to RF and baseband (BB) processing. Our emphasis is to cover the BB part, including the coding, modulation, and waveform generation functions, which are mostly using the tools and techniques from digital signal processing. But we also look at the overall transceiver from the RF system point of view, covering issues like frequency translations and channelization filtering, as well as emerging techniques for mitigating the inevitable imperfections of the analog RF circuitry through advanced digital signal processing methods

Rationale, design, implementation, and baseline characteristics of patients in the DIG trial: A large, simple, long-term trial to evaluate the effect of digitalis on mortality in heart failure

This article provides a detailed overview of the rationale for key aspects of the protocol of the Digitalis Investigation Group (DIG) trial. It also highlights unusual aspects of the study implementation and the baseline characteristics. The DIG trial is a large, simple, international placebo-controlled trial whose primary objective is to determine the effect of digoxin on all cause mortality in patients with clinical heart failure who are in sinus rhythm and whose ejection fraction is less than or equal to 0.45. An ancillary study examines the effect in those with an ejection fraction > 0.45. Key aspects of the trial include the simplicity of the design, broad eligibility criteria, essential data collection, and inclusion of various types of centers. A total of 302 centers in the United States and Canada enrolled 7788 patients between February 1991 and September 1993. Follow-up continued until December 1995 with the results available in Spring 1996