Described is a communications system for transmitting baseband and broadband signals simultaneously. The system is ideally suited for interconnecting different types of data terminal equipment (DTE) within a building or limited geographical area. The system includes a backbone communications network formed from a plurality of independent communications systems. Each of the plurality of independent communications systems is dedicated to transmit either the baseband signals or the broadband signal...

A signal processing system includes a main digital-to-analog converter (DAC) for receiving a digital baseband signal and converting the digital signal into an analog signal. Also included in the system is a connection circuit for receiving the analog signal, and output terminal, and an analog filter coupled between the connection circuit and the output terminal for filtering the analog signal. The system includes a calibration circuit coupled between the connection circuit and the output termina...

A base band receiver apparatus comprising an RF front end section, a pulse detection unit wherein modulated, ultra-short spread spectrum pulses are detected, and a data recovery unit wherein clock and data recovery from the detected pulses are carried out. The RF front end includes an antenna and circuitry for filtering and amplifying RF signals received by the antenna. The pulse detection unit preferably includes a tunnel diode or Schottky diode which rectifies the incoming voltage signals from...

A binary data multiplexing system is disclosed wherein data from a binary source is applied to two encoders. One encoder operates to impart a self-clocking coding to the data and to thus cause the data to lie in a frequency band near the upper limits of the baseband frequency spectrum of the system. The second encoder operates to impart a low frequency coding to the data and to thus cause the data to lie in a frequency band near the lower limits of the baseband frequency spectrum of the system. ...

A baseband carrier phase corrector is disclosed which permits rapid demodulation and demodulation of varying RF input signals. The baseband carrier phase corrector receives RF signals, or alternatively, IF signals, and converts the signals to baseband. An RF signal received by the baseband carrier phase corrector is split and multiplied with oscillating signals having a 90 degree phase differential. The resultant signals are baseband in-phase (I) and quadrature (Q) signals. The I and Q signals a...

A baseband signal communication apparatus includes a transmission unit and a reception unit. The transmission unit superposes a subcarrier on one value of a baseband signal consisting of binary values, modulates a carrier with the baseband signal on which the subcarrier is superposed, and transmits the baseband signal as a transmission signal wave. The reception unit demodulates the baseband signal having the subcarrier superposed thereon by using a demodulator upon reception of the transmission...

The signal path between the input and output of a baseband video switch has a control point to which a signal representative of a switch control signal and a switchable constant current source are coupled. A pair of diodes and a switchable, high impedance buffer are disposed in series between the input terminal and the control point. A diode and a switchable driver are connected in series between the control point and the output terminal. A biasing arrangement responsive to the control signal bi...

A baseband-controlled passband equalizing arrangement comprises a passband correction circuit for the data signals transmitted by modulating a carrier frequency, a first demodulation circuit which cooperates with a carrier recovery circuit for converting these carrier-modulated data signals into baseband signals, and a control circuit acting on the variable elements provided in the passband correction circuit in response to an estimated error of the baseband signals. The passband correction circ...

Pulse code modulation system for reducing bandwidth in which voice signal input is compressed, limited, filtered into frequency channels, all of which are converted to the same baseband frequency and are fed to a time sharing multiplexing circuit followed by an analog to digital circuit for transmission. The digital signal is received, converted to analog, demultiplexed, demodulated to voice frequency channels and bandpass filtered. The number of channels applied to the time sharing circuit can ...

A transversal filter equalizer comprising a programmable transmitter baseband equalizer for use in high rate digital transmitters. The programmable transmitter baseband equalizer processes digital data using a 1/2-symbol spaced transversal filter to produce I and Q baseband signals. The 1/2-symbol spaced transversal filter comprises I and Q n-bit wide shift register stages having alternate pairs of I and Q shift register stages driven by opposite phases of an input data clock, multiplying digita...