Digital signal

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

Radio communication system

Abstract: A CW (Continuous Wave) radio frequency signal converted to an IF (Intermediate Frequency) signal is mixed with a local oscillator signal by an IF mixer, and the obtained signal is converted to a digital signal by an ADC (Analog-to-Digital Converter). A digital bandpass filter passes only the target component in the output of the ADC. The passed IF signal is demodulated by a digital demodulator, and the demodulated signal is converted to an analog signal before being output as a sound. When pitch control to increase the reception pitch by DELTA f is instructed, an MPU (Microprocessor Unit) alters the frequency of the local oscillator signal by DELTA f as well as the center frequency of the digital bandpass filter by DELTA f, so that the center frequency of the input signal to a narrow-band filter coincides with the center frequency of the digital bandpass filter.

System, method and computer program for an integrated digital workflow for processing a paper form

Abstract: A method, system and computer program for creating a digital workflow associated with the completion of a paper form is provided. An electronic clipboard includes a panel for receiving a paper form, a computer including a clipboard computer application, and an input device that completes the paper form with handwritten input data and also created digital signals corresponding to the handwritten input data. The computer application interprets the digital signal data so as to define digital input data, which corresponds to the handwritten input data. The electronic clipboard also includes verification/correction facility that enables the display of the digital input data and verification and correction thereof using a series of input devices provided on the electronic clipboard. The electronic clipboard is linked to a remote computer. The remote computer includes a forms creation and management application for the creation of the electronic forms, and definition of rules for processing digital input data includes in the various fields of the electronic forms. In a server implementation of the invention, the remote computer is an application server that provides access to a plurality of software utilities for processing the digital input data included in the electronic forms. The application server enables processes such as financial transactions associated with electronic forms, transmission of selected digital input data to other computer systems, and field level encryption. Another aspect of the invention is a point of sale device that include the electronic clipboard.

Digital Camera with Selectively Increased Dynamic Range By Control of Parameters During Image Acquisition

Abstract: A parameter of a digital camera or other digital image acquisition device is adjusted to maintain the resulting digital signal within a range carried by a digital processing path that carries a limited number of bits. The magnitude of the parameter is then also used to represent the image. Examples of the parameter include analog signal gain and exposure time. This is a cost effective way to increase the dynamic range of a digital camera, instead of increasing the width of its digital processing path. The digital data may be processed to obtain either tone mapped images, which are compatible with current cameras and other equipment, or to obtain images with a greater dynamic range for use with suitable displays and the like.

Digital delay lock loop for clock signal frequency multiplication

Abstract: A digital delay lock loop for generating frequency multiples of an input clock signal includes a programmable digital oscillator, a phase comparator, a programmable counter and delay control logic. The programmable digital oscillator is a ring connected programmable delay line and inverter which together generate an output clock signal having a frequency which depends upon the time delay of the programmable delay line. The phase comparator compares the phase of the output clock signal to that of a reference clock signal and generates a phase error signal which represents the phase difference between such signals. The programmable counter, programmed and reprogrammed with the arrival of every reference clock signal pulse, counts the output clock signal pulses to generate a count signal. The delay control logic, in response to the phase error signal and count signal, programs the time delay of the programmable delay line, thereby causing the output clock signal frequency to be the desired multiple of the reference clock frequency.

Voltage to pulse-width conversion circuit

Abstract: A voltage to pulse-width conversion circuit includes a counter which counts a reference frequency signal and produces a multi-bit digital value; a digital/analog converter which converts the digital value into an analog signal; and a voltage comparator which compares an output of the digital/analog converter with a control signal and produces a pulse width modulated output signal which has a predetermined duty cycle ratio.