Digital signal

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

Digital automatic gain control apparatus

Abstract: A digital automatic gain control apparatus is provided which controls gain such that when an analog video signal is converted into digital signals for processing, the input of the A-D converter is maintained at a fixed level, and after the analog signal has been converted into digital form, the output of the digital system circuit is also maintained at a fixed level. In this apparatus, an input signal is passed through an analog variable gain amplifier, the signal is converted into digital form, and the output of an A-D converter is passed through a digital variable gain amplifier. The amplitude level of the output of the digital variable gain amplifier is detected by an amplitude detecting unit and is controlled so as to be equal to a specified reference value. At this time, the analog variable gain amplifier is controlled so that the level of the control signal for controlling the digital variable gain amplifier is equal to a specified reference value, thereby maintaining the signal of the A-D converter at a fixed level. Gain control of the analog signal system and the digital signal system, before and after the A-D converter, is effected by a single amplitude detecting unit.

Ultrasound-based 3-d tracking system using a digital signal processor

Abstract: This invention is a system (50) for determining a time delay of a signal (56) propagating through a medium. The time delay is used to determine the distance between transducers (52, 54) arranged within a body. One or more Digital Signal Processors (DSP) (70) are programmed to recognize various waveform patterns by matching a received waveform to a template waveform.

Communication server apparatus using digital signal switching and method

Abstract: A communication server (58) using digital signal switching is provided. A plurality of twisted pair subscriber lines are split into twisted pair data lines (54) and twisted pair phone lines (52). Analog signals received on the twisted pair data lines (54) are converted into incoming parallel digital words and outgoing parallel digital words are converted into analog signals for transmission on the twisted pair data lines (54) using first converters (614) coupled to each twisted pair data line (54). The incoming parallel digital words are converted into incoming serial bit streams and outgoing serial bit streams are converted into the outgoing parallel digital words using second converters (616) coupled to the first converters (614). A need for data service is detected on a selected twisted pair data line (54), and one of the XDSL modems (620) is selected in response to detecting the need for data service. The selected XDSL modem (620) is then coupled to a second converter (616) associated with the selected twisted pair data line (54) where the selected XDSL modem (620) receives the incoming serial bit stream from and provides the outgoing serial bit stream to the associated second converter (616).

Speakers with a digital signal processor

Abstract: A speaker with a digital signal processor is disclosed. In one aspect, a speaker comprises at least one electromechanical transducer configured to convert an electrical audio signal into sound and a digital signal processor configured to process an audio signal and send the processed audio signal to the electromechanical transducer directly or indirectly.