In this letter, we extend our investigation of generalized multicarrier direct-sequence code-division multiple access by considering two additional types of chip waveforms, namely, the time-domain half-sine and raised-cosine chip waveforms, in addition to the rectangular chip waveform. A range of closed-form equations are provided for quantifying the effect of both the multipath interference an...

Introduction: Measuring microstructure parameters of brain tissue, such as axon radius, in vivo is a challenge in diffusion MRI. Current approaches typically use pulsed-gradient spin-echo (PGSE) [1] or stimulated-echo (STEAM) [2] sequences, both of which use a rectangular diffusion-gradient pulse. However other shapes of diffusion-gradient pulses such as oscillating [3] or chirped [4] may provi...

We investigate the performance of frequency division multiplexed (FDM) signals, where multiple orthogonal Hermite-Gaussian carriers are used to increase the bandwidth efficiency. Multiple Hermite-Gaussian functions are modulated by a data set as a multicarrier modulation scheme in a single time-frequency region constituting toroidal waveform in a rectangular OFDMA system. The proposed work outp...

Gaussian pulse shaping is used in digital communication systems like DECT, GSM,WLAN to minimize the out of band spectral energy. The baseband rectangular pulse stream is passed through a lter with a Gaussian impulse response before frequency modulating the carrier. Traditionally this is done by storing the values of the pulse shape in a ROM and converting it to an analog waveform with a DAC fol...

The delivery of therapeutic levels of electrical current to neural tissue is a well-established treatment for numerous indications such as Parkinson's disease and chronic pain. While the neuromodulation medical device industry has experienced steady clinical growth over the last two decades, much of the core technology underlying implanted pulse generators remain unchanged. In this study we pro...

Three waveforms for transthoracic defibrillation are assessed and compared: the Pulsed Biphasic Waveform (PBW), the Rectilinear Biphasic Waveform (RBW), and the “lossless” constant current (LLCC) pulses. Two indices are introduced: 1) kf = W/W0 – the ratio between the delivered energy W and the energy W0 of a rectangular pulse with the same duration and electric charge; 2) ηC = W/WC0 – the leve...

The ionic mechanism underlying optimal stimulus shapes that induce a neuron to fire an action potential, or spike, is relevant to understanding optimal information transmission and therapeutic stimulation in the nervous system. Here we analyze for the first time the ionic basis for stimulus optimality in the Hodgkin and Huxley model and for eliciting a spike in squid giant axons, the preparatio...

architecture of the maize leaf epidermis would make any bricklayer proud. Most of the epidermal cells arise through symmetric divisions in which new cell walls are made either parallel or perpendicular to the long axis of the mother cell. Long, parallel rows of rectangular cells are the result. Specialised cell types, however, are formed through asymmetric divisions. These include the diamond-s...