Dynamic resource allocation based on the current channel state is a promising strategy to increase the capacity of wireless links. In this paper, the optimum accessing and resource allocation scheme for fading multiple–access channels with partial CSI at the transmitters are found. Partial knowledge of the fading states is a reasonable assumption for systems which provide a low rate feedback ch...

We investigate the secure degrees of freedom (SDoF) of a two-transmitter Gaussian multiple access channel with multiple antennas at the transmitters, a legitimate receiver and an unknown number of eavesdroppers each with a number of antennas less than or equal to a known value NE . The channel matrices between the legitimate transmitters and the receiver are available everywhere, while the legi...

In wireless positioning systems, the transmitter's power is usually fixed. In this paper, we explore the use of varying transmission powers to increase the performance of a wireless localization system. To this extent, we have designed a robot positioning system based on wireless motes. Our motes use an inexpensive, low-power sub-1-GHz system-on-chip (CC1110) working in the 433-MHz ISM band. Ou...

– In this paper we describe a method for designing broadcasting HF communication systems capable of accomplishing wide coverage using reduced power transmitters. Given a set of available frequencies and the transmitters maximum power, we provide the frequencies subset that must be used for different time intervals, during each month of the year for a given solar activity. This method is based o...

The part of the brain most important in regulating sleep duration is the hypothalamus. Certain groups of hypothalamic neurons and adjacent groups of basal forebrain neurons produce the neurotransmitter gamma-aminobutyric acid (GABA). Projections of these GABA neurons inhibit the firing of cells involved in wakefulness. Several groups of neurons have been shown to be inhibited by this action--in...

The use of solid-state transmitters is becoming increasingly viable for atmospheric radars and is a key part of the strategy to realize any dense network of low-powered radars. However, solid-state transmitters have low peak powers and this necessitates the use of pulse compression waveforms. In this paper frequency diversity in a wideband waveform design is proposed to mitigate the low sensiti...

This paper concerns the transmission of two independent Gaussian sources over a two-user decentralized interference channel, assuming that the transmitters are unaware of the instantaneous CSIs. The availability of the channel state information at receivers (CSIR) is considered in two scenarios of perfect and imperfect CSIR. In the imperfect CSIR case, we consider a more practical assumption of...

The autonomic nervous system (ANS) controls body functions that can proceed independent of volitional activity . The system consists of a somatic afferent pathway, a central nervous system (CNS) integrating complex (brain and spinal cord), and two distinct efferent limbs (sympathetic and parasympathetic) each made up of preganglionic and postganglionic neurones . The viscera are innervated by b...

extremely low frequency (elf) electromagnetic field (elf-emfs) are widely employed in electrical appliances and different equipment such as television sets, elf-emfs can  affect biological systems by increasing production  ros. the altered balance between ros generation and elimination plays a critical role in a variety of pathologic conditions. ros levels have been observed in several hematopo...

We consider multichannel multihop lightwave networks with stations equipped with a small number of transmitters and receivers. By assigning wavelengths to the receivers and transmitters at each station, one can de ne the logical connectivity of the network independently of the underlying physical topology. The advent of fast tunable optical transmitters and receivers makes it feasible to dynami...