AGC was implemented in first radios for the reason of fading propagation (defined as slow variations in the amplitude of the received signals) which required continuing adjustments in the receiver‟s gain in order to maintain a relative constant output signal. Such situation led to the design of circuits, which primary ideal function was to maintain a constant signal level at the output, regardl...

This article gives a presentation of the Automatic Gain Control algorithm used in WCDMA (3rd generation mobile networks). The focus is on how the controller bandwidth influences settling times and modulation distortion. This will be investigated through simulation for two different channel cases.

The auditory system must represent sounds with a wide range of statistical properties. One important property is the spectrotemporal contrast in the acoustic environment: the variation in sound pressure in each frequency band, relative to the mean pressure. We show that neurons in ferret auditory cortex rescale their gain to partially compensate for the spectrotemporal contrast of recent stimul...

A switched sliding mode control strategy for a class of nonlinear uncertain systems is presented in this paper. It is characterized by an event– driven gain reduction mechanism which relies on a decomposition of the system state into regions. By enforcing sliding mode behaviors on a suitable set of sliding manifolds, while avoiding the generation of limit cycles, the proposed strategy proves to...

The physiology of climbing fiber signals in cerebellar Purkinje cells has been studied since the early days of electrophysiology. Both the climbing fiber-evoked complex spike and the role of climbing fiber activity in the induction of long-term depression (LTD) at parallel fiber-Purkinje cell synapses have become hallmark features of cerebellar physiology. However, the key role of climbing fibe...

Sensorineural hearing loss induced by noise or ototoxic drug exposure reduces the neural activity transmitted from the cochlea to the central auditory system. Despite a reduced cochlear output, neural activity from more central auditory structures is paradoxically enhanced at suprathreshold intensities. This compensatory increase in the central auditory activity in response to the loss of senso...

Multiplicative gain control is a vital component of many theoretical analyses of neural computations, conferring the ability to scale neuronal firing rate in response to synaptic inputs. Many theories of gain control in single cells have used precisely balanced noisy inputs. Such noisy inputs can degrade signal processing. We demonstrate a deterministic method for the control of gain without th...

In overloaded CDMA systems the high correlation among users’ signatures determines an overall performace that can be quite poor even for the optimal ML receiver. The geometric properties of signatures affect users’ separability, a condition that is necessary for achieving asymptotic efficiency. In this paper we establish gaussian separability conditions and propose an algorithm for the design o...

The adaptive high-gain output feedback strategy ( ) = ( ) ( ), ( ) ( ) = ( ) is well established in the context of linear, minimum-phase, -input -output systems ( , , ) with the property that spec( ) ; the strategy applied to any such linear system achieves the performance objectives of: 1) global attractivity of the zero state and 2) convergence of the adapting gain to a finite limit. Here, th...

A plaid is a combination of two gratings whose orientations are orthogonal to each other with the same or similar contrasts. We used plaid patterns as stimuli to investigate the mechanisms underlying the detection of a plaid to understand how the visual system combines information from orientation-selective channels. We used a masking paradigm in which an observer was required to detect a targe...