No abstract

No abstract

The Frequency Modulated Ultra-Wideband (FM-UWB) is known as a low-power, low-complexity modulation scheme targeting low to moderate data rates in applications such as wireless body area networks. In this paper, a thorough review of all FM-UWB receivers and transmitters reported in literature is presented. The emphasis is on trends in power reduction that exhibit an improvement by a factor 20 over the past eight years, showing the high potential of FM-UWB. The main architectural and circuit techniques that have led to this improvement are highlighted. Seldom explored potential of using higher data rates and more complex modulations is demonstrated as a way to increase energy efficiency of FM-UWB. Multi-user communication over a single Radio Frequency (RF) channel is explored in more depth and multi-channel transmission is proposed as an extension of standard FM-UWB. The two techniques provide means of decreasing network latency, improving performance, and allow the FM-UWB to accommodate the increasing number of sensor nodes in the emerging applications such as High-Density Wireless Sensor Networks.

We quickly form first impressions about newly encountered people guiding our subsequent behaviour (approach, avoidance). Such instant judgments might be innate and automatic, being performed unconsciously and independently to other cognitive processes. Lying detection might be subject to such a modular process. Unfortunately, numerous studies highlighted problems with lying detection paradigms such as high error rates and learning effects. Additionally, humans should be motivated doing both detecting others’ lies and disguising own lies. Disguising own lies might even be more challenging than detecting other people’s lies. Thus, when trying to disguise cheating behaviour, liars might display a mixture of disguising (fake) trust cues and uncontrolled lying cues making the interpretation of the expression difficult (perceivers are guessing). In two consecutive online studies, we tested whether seeing an increasing amount (range 0–4) of lying cues (LC) and non-lying cues (NLC) on a standard face results in enhanced guessing behaviour (studies 1 and 2) and that enhanced guessing is accompanied by slower responding (study 2). Results showed that pronounced guessing and slowest responding occurred for faces with an intermediate number and not with the highest number of LC and NLC. In particular, LC were more important than NLC to uncertain lying decisions. Thus, only a few LC may interfere with automatic processing of lying detection (irrespective of NLC), probably because too little lying cue information is yet available.

This paper presents a 4-GHz FM ultra-wideband (UWB) transceiver designed for the Internet of Things and body area network applications. Robustness to interferers and low power spectral density allow FM-UWB to coexist with narrowband radios, while large signal bandwidth strongly relaxes constraints on the frequency synthesis blocks enabling the full integration of the radio at low power. The transceiver, integrated with a 65-nm standard CMOS technology, consists of a transmitter and two receivers that provide two modes of operation. The transmitter consumes 575 µW while transmitting a 100-kb/s signal at 4 GHz at an output power of −11.4 dBm. A single RF IO pad is used and the fully integrated matching network is shared among the transmitter and the receivers. The low-power receiver consumes 267 µW and provides a single communication channel at 100 kb/s in the 4-GHz band, with a −57-dBm sensitivity. The second receiver provides a better performance and takes full advantage of the FM-UWB features, as it implements wireless communication with up to four parallel channels sharing the same RF band. It consumes 550 µW and provides −68-dBm sensitivity at 100 kb/s per channel. The FM-UWB architecture can tolerate a very large reference frequency offset of up to ±8000 ppm. This unique feature potentially allows for a quartzfree synthesizer, resulting in a radio with no off-chip components.