Digital signal

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

Packet identification mechanism at the transmitter and receiver for an enhanced ATSC 8-VSB system

Abstract: A flexible digital transmission system that improves upon the ATSC A/53 HDTV signal transmission standard. The system includes a digital signal transmitter for generating a first Advanced Television Systems Committee (ATSC) standard encoded 8-VSB bit stream and, for generating an encoded new robust bit stream for transmitting high priority information bits, wherein symbols of the new bit stream are capable of being transmitted according to a transmission mode including: a 2-VSB mode and a 4-VSB transmission mode. The standard 8-VSB bit stream and new bit stream may be simultaneously transmitted over a terrestrial channel according to a broadcaster defined bit-rate ratio. The transmission system includes a control mechanism for generating information needed for encoding robust packets at a transmitter device. It also includes a mechanism for encoding control parameters and multiplexes the generated information with the standard and robust bit-streams for transmission. A receiver architecture is additionally provided to decode standard and robust bit-streams transmitted by the transmitter device.

Polyphase channelization system

Abstract: A polyphase channelizer converts an intermediate frequency wideband signal into a complex signal that is sampled by parallel analog-to-digital converters having a bank of samplers respectively clocked by staggered clocking signals for respective converters for feeding I and Q quadrature samples to a polyphase filter bank of finite impulse response filters driving a fast Fourier transform processor for providing channelized digital signal outputs. The parallel analog-to-digital converters can operate at lower speeds but are parallel connected for effectively operating at required higher speeds. The channelizer channelizes the wideband signal using a polyphase clock for enabling high speed sampling and converting through low speed parallel analog to digital converters.

Recording and reproducing apparatus with limited digital copying

Abstract: A composite digital signal received by a recording and reproducing apparatus includes a digital information signal and a control signal. The control signal represents a number of digital copy generation of the associated information signal. The information signal of the received digital composite signal is recorded into recording medium. The information signal is reproduced from the recording medium. During the reproduction of the information signal, a new control signal is generated which represents a number equal to one plus the number represented by the control signal of the received composite digital signal. The new control signal and the reproduced information signal are combined into a new composite digital signal. The new composite digital signal is outputted. A check is made as to whether or not the number represented by the control signal of the received composite digital signal is equal to a predetermined number. When the number represented by the control signal of the received composite digital signal is equal to the predetermined number, the recording of the information signal of the received composite digital signal is inhibited.

Audio storage and distribution system

Abstract: This invention relates to an electronic system and a method for storing and distributing audio signals over existing communication lines. The system comprises a compressor for compressing in a predetermined manner the waveform amplitude of an input analog signal, thereby forming a compressed analog signal. The compressed analog signal is then converted into a digital signal by an analog to digital converter. A digital interface subsystem stores and retrieves selected ones of the digital signals for transmission over a communications line. At a remote end of the communications line the digital signal is converted back to its analog compressed signal representation by a digital to analog converter. The compressed analog signal is then expanded in a manner complimentary to the compressor operation, thus reconstructing the analog signal. A selector generator is provided at the remote end of the communications line for generating a command signal over the communications line to command the digital interface subsystem to select the desired one of the stored digital signals.

Broadcast receiver, transmission control unit and recording/reproducing apparatus

Abstract: A method for receiving a broadcast includes the steps of receiving a digital signal obtained by multiplexing at least one program; selecting data corresponding to one program among the at least one program multiplexed in the digital signal, decoding the selected data; and selecting data corresponding to at least one program among the at least one program multi- plexed in the digital signal, and transmitting the selected data to an external device.