We consider the problem of covert communication over a state-dependent channel, where the transmitter has causal or noncausal knowledge of the channel states. Here, “covert” means that a warden on the channel should observe similar statistics when the transmitter is sending a message and when it is not. When a sufficiently long secret key is shared between the transmitter and the receiver, we d...

A chaotic transmitter and a synchronized chaotic receiver have been designed in a 0.25um CMOS process. Both transmitter and receiver use conversions between voltage and time to implement nonlinear tent-map functions. The transmitter outputs chaotic pulse position modulated (C-PPM) data as a stream of 2.3V p-p pulses of <1ns duration. The chaotic receiver uses the timing information between puls...

Curarized cutaneous pectoris nerve-muscle preparations from frogs were stimulated at 10/s or at 2/s for periods ranging from 20 min to 4 h. End plate potential were recorded intracellularly and used to estimate the quantity of transmitter secreted during the period of stimulation. At the ends of the periods of stimulation the preparations were either fixed for electron microscopy or treated wit...

This paper explores the concept of a Forward Scattering Radar (FSR) system with a rotational transmitter for target detection and localization. Most of the research and development in FSR used a fixed dedicated transmitter; therefore, the detection of stationary and slow moving target is very difficult. By rotating the transmitter, the received signals at the receiver contain extra information ...

For fully autonomous implantable or body-worn devices running on harvested energy, the peak and average power dissipation of the radio transmitter must be minimized. We propose a highly integrated 90μW 400MHz MICS band transmitter with an output power of 20μW leading to a 22% global efficiency — the highest reported to date for such systems. We introduce a new transmitter architecture based on ...

Among the many forms of brain plasticity, changes in synaptic strength and changes in synapse number are particularly prominent. However, evidence for neurotransmitter respecification or switching has been accumulating steadily, both in the developing nervous system and in the adult brain, with observations of transmitter addition, loss, or replacement of one transmitter with another. Natural s...

We derive the ergodic capacity region for a fading broadcast channel when the transmitter knows only the channel ordering information of the users and the receiver knows its transmitter-receiver channel gain and the ordering information at any time instant. We show that superposition coding based on the ordering information achieves the ergodic capacity region. Moreover, we prove that as the nu...

This paper presents a fully integrated all-digital ultra-wideband (UWB) transmitter. All functional blocks in the transmitter are implemented with digital standard cells and automatically placed-and-routed (APR-ed) by design tools. The center frequency and the bandwidth of the UWB pulses are digitally tuned to compensate for variations, and a calibration scheme utilizing APR mismatch is explore...

This paper presents the transmitter circuit designed for the application of wireless capsule endoscope to overcome the limitation of conventional endoscope. The design is performed using CMOS 0.13 μm technology. The transmitter is designed to operate at centre frequency of 433.92 MHz, which is one of the ISM band. Active mixer and ring oscillator made up the transmitter and it consumes 1.57 mA ...

A 2.4-GHz CMOS on-off keying (OOK) transmitter is developed for applications that require high data rate over 10Mbps in the area of wireless body area network (WBAN) and medical implant communication service (MICS). A novel analog pulse-shaping circuit for reducing power consumption and circuit complexity is employed for the OOK transmitter. Fabricated in 0.13μm CMOS, the transmitter core exclu...