Digital signal

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

Method and apparatus for receiving diversity signals for use in OFDM radio communication system

Abstract: A diversity receiving apparatus for use in an OFDM transmission radio communication/broadcasting system where OFDM signals are received by a plurality of antennas and input into a plurality of receivers. The OFDM received signals are further transformed into frequency spectra. Channel frequency responses are calculated by using OFDM received signal frequency spectra and a reference frequency spectrum generated in a reference spectrum generator. OFDM received signal frequency spectra distortions are compensated by using corresponding channel frequency responses. The transformed OFDM received signal frequency spectra are input into a selector unit as first input signals, while the distortion-compensated OFDM received signal frequency spectra are input into the selector unit as second input signals. The selector unit then selects a second input signal corresponding to a first input signal having maximum amplitude or maximum power. A demodulator then demodulates the output signal of the selector unit into a digital signal sequence.

Video printer with separately stored digital signals printed in separate areas to form a print of multiple images

Abstract: A video printer is disclosed. An input video signal is converted into a digital signal and stored in a memory. The write/read operation and memory addresses of the memory are controlled by a memory control unit. The signal read out of the memory is converted into print data, and an image is printed by a printer. The print data and the printing operation are controlled by a print control unit, and at least a part of the memory areas of the memory is controlled in the write operation by an area control unit.

Method and system for down-converting an electromagnetic signal, transforms for same, and aperture relationships

Abstract: Methods, systems, and apparatuses, and combinations and sub-combinations thereof, for down-converting an electromagnetic (EM) signal are described herein. Briefly stated, in embodiments the invention operates by receiving an EM signal and recursively operating on approximate half cycles (½, 1½, 2½, etc.) of the carrier signal. The recursive operations can be performed at a sub-harmonic rate of the carrier signal. The invention accumulates the results of the recursive operations and uses the accumulated results to form a down-converted signal. In an embodiment, the EM signal is down-converted to an intermediate frequency (IF) signal. In another embodiment, the EM signal is down-converted to a baseband information signal. In another embodiment, the EM signal is a frequency modulated (FM) signal, which is down-converted to a non-FM signal, such as a phase modulated (PM) signal or an amplitude modulated (AM) signal.

D/A converter and delta-sigma D/A converter

Abstract: A D/A converter for converting a given digital signal into an analog signal includes a plurality of capacitors (C1, C2 ..., Ci) for storing an electric charge corresponding to a predetermined reference voltage (Vr + or Vr-). The reference voltage is selected depending on the digital signal during a period when a clock 1 is at a high level. A switch selection (SUG1 - SUGi, SB) is used to connect each of the plurality of capacitors between an input terminal and an output terminal of an operational amplifier 100 during a period when a clock 2 is at a high level.

Method and system for down-converting an electromagnetic signal, and transforms for same

Abstract: Methods, systems, and apparatuses, and combinations and sub-combinations thereof, for down-converting an electromagnetic (EM) signal are described herein. Briefly stated, in embodiments the invention operates by receiving an EM signal and recursively operating on approximate half cycles (½, 1½, 2½, etc.) of the carrier signal. The recursive operations can be performed at a sub-harmonic rate of the carrier signal. The invention accumulates the results of the recursive operations and uses the accumulated results to form a down-converted signal. In an embodiment, the EM signal is down-converted to an intermediate frequency (IF) signal. In another embodiment, the EM signal is down-converted to a baseband information signal. In another embodiment, the EM signal is a frequency modulated (FM) signal, which is down-converted to a non-FM signal, such as a phase modulated (PM) signal or an amplitude modulated (AM) signal.