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Digital signal

About: Digital signal is a research topic. Over the lifetime, 44213 publications have been published within this topic receiving 345279 citations.


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Patent
Mayo Frank1
25 Oct 1991
TL;DR: In this article, a method and apparatus for generating correction signals for use in forming low-distortion analog signals was proposed, where a digital representation of a desired analog waveform is encoded into a digital data signal which is outputted to memory.
Abstract: A method and apparatus for generating correction signals for use in forming low distortion analog signals. A digital representation of a desired analog waveform is encoded into a digital data signal which is outputted to memory. A digital correction signal is encoded, having an opposite phase and increased amplitude from the signal distortion which it is determined will occur when the digital data signal is repetitively read out of memory and decoded. This digital correction signal is outputted to memory. The digital data and correction signals are repetitively and synchronously read out of memory into a decoder. The decoder converts both digital signals into analog signals, so that the analog correction signal may superpose on the distortion in the analog data signal, resulting in a low distortion analog signal.

64 citations

Patent
16 Aug 1993
TL;DR: An early warning system for visually informing the hearing impaired driver of an automotive vehicle of the proximity of an emergency vehicle by detecting a siren being sounded by the emergency vehicle is described in this article.
Abstract: An early warning system (10) for visually informing the hearing impaired driver (D) of an automotive vehicle (A) of the proximity of an emergency vehicle by detecting a siren being sounded by the emergency vehicle A microphone unit (12) receives an audible frequency signal transmitted by the siren This signal is in one of a band of audible frequencies In addition to the siren, the microphone unit receives other audible frequency signals as well A signal processor (22) processes all received audible frequency signals The processor includes an analog-digital converter (30) for converting received signals to a digital signal The processor further includes a correlator microprocessor (32) for comparing the resulting processed signal to known siren signal characteristics each of which identifies a different type of siren A light indicator (D1) provides a visible signal to the driver of the proximity of an emergency vehicle and an audible warning is also provided These warnings allow the driver time to take appropriate action to avoid the emergency vehicle The indicator is illuminated when a correlation is found indicating a received signal corresponds with the sound made by an emergency vehicle siren

64 citations

Patent
30 Nov 1993
TL;DR: In this paper, a three-input arithmetic logic unit (ALU) is embodied in a data processor circuits as a part of a multiprocessor integrated circuit (100) used in image processing.
Abstract: A data processing apparatus includes a three input arithmetic logic unit (230) that generates a combination of the three inputs that is selected by a function signal. Data registers (200) store the three data inputs and the arithmetic logic unit output. The second input signal optionally comes from a controllable shifter (235). The shift amount is a default shift amount stored in a special data register, a predetermined set of bits of data recalled from a data register or zero. A one's constant source (236) is connected to the shifter (235) to supply an N bit digital signal of "1". This permits generating a second input signal of the form 2N, with N being the shift amount. The output of the shifter (235) may be stored independently of the arithmetic logic unit (230) result. The third input signal optionally comes from a multiplexer (233) that selects between an instruction specified immediate field, data recalled from a data register or a mask input from a mask generator (239). This mask input signal may be the default shift amount or a predetermined number of the least significant bits of a third input signal as selected by a multiplexer. In the preferred embodiment of this invention, the three input arithmetic logic unit (230) is embodied in a data processor circuits as a part of a multiprocessor integrated circuit (100) used in image processing.

64 citations

Patent
Eric J. Swanson1
01 Feb 2002
TL;DR: In this paper, an analog-to-digital conversion system is described, which includes a digitally programmable preamplifier for amplifying a difference between an analog input and an estimate of the analog input.
Abstract: An autoranging analog to digital conversion system is provided. The system may include a digitally programmable preamplifier for amplifying a difference between an analog input and an estimate of the analog input. The preamplifier may be coupled to an analog to digital converter for converting the preamplifier output to a digital signal. The system may also include digital domain predictor or estimation logic for determining an optimum gain and analog input estimate for a given analog input. Multiple signal input channels may be coupled to the analog to digital conversion system. The autoranging estimations may be performed on a sample by sample basis or a channel by channel basis. The conversion system may also include the use of a backup conversion path for use when the main conversion path overranges. The backup conversion path may utilize a dedicated backup converter. The backup conversion path may alternatively utilize the estimation converter to generate backup conversions or may utilize the main converter to generate backup conversions.

64 citations

Proceedings ArticleDOI
01 Nov 2007
TL;DR: In this paper, the authors compare three generations of digital control in power electronics: First-generation digital control uses digital outside the loop, including discrete-time feedback loops and digital signal processing, second generation digital controls use digital processes inside the loop and third generation digital process functions directly with individual switches to push performance up to the physical limits of power electronics.
Abstract: Digital control in power electronics can be divided into three "generations" First-generation digital controls use digital "outside the loop" in communications, setup, and supervisory roles Second generation digital controls use digital processes "inside the loop," including discrete-time feedback loops and sometimes even digital signal processing Today, first-generation digital methods are expanding quickly, as new communication protocols and adjustable analog loops become common Even companies that continue to design analog controls for power electronics often include these types of digital processes Second-generation digital controls are a hot topic right now, as real-time digital controllers become feasible In third-generation digital controls, the digital process functions directly with individual switches to push performance up to the physical limits of power electronics A digital switch decides when it must turn on or off The control is on direct switch timing rather than a converter duty ratio or a setting Extreme performance is possible with this approach, such as converters that do not exhibit output disturbances when confronted with load or line step changes The talk compares these different arenas, all of which are current active topics in power electronics, and shows what can become possible as the third generation develops

64 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20239
202225
2021190
2020755
2019942
2018915