A method and apparatus for dynamically modifying filter characteristics of a delta-sigma modulator in order to perform signal equalization of a signal in the delta signal modulator. The system is used for wide bandwidth radio system designed to adapt to various global radio standards and, more particularly, to a cellular radio architecture that employs a combination of a single circulator, programmable band-pass sampling radio frequency (RF) front-end and optimized digital baseband that is capable of supporting all current cellular wireless access protocol frequency bands.

The purpose of the present invention is to provide a high-power-efficiency and low-design-cost transmission device by implementing, with a constant clock, delta-sigma modulation maintaining a zero current switching property in an amplifier. This delta-sigma modulator comprises: a pulse phase signal generation unit for generating a pulse phase signal from a phase signal; a delta-sigma modulation unit for generating a pulse amplitude signal obtained by delta-sigma modulating an amplitude signal with a constant clock; a phase sorting unit for outputting a control signal on the basis of the phase signal; a delay switching unit for delaying the pulse amplitude signal on the basis of the control signal; and a mixing unit for outputting a pulse string obtained by multiplying together the delayed pulse amplitude signal and the pulse phase signal.

A feedback control system may include a feedback controller for controlling a plant using pulse density signals. The feedback controller may include a pulse density signal generator and a controller logic circuit. The pulse density signal generator may receive input command signals and generate signed or unsigned pulse density input signals. The controller logic may receive the pulse density input signals from the pulse density signal generator and feedback pulse density signals from the plant and may generate corresponding pulse density control signals for controlling the plant based on the input command signals. The controller logic may include a sign change logic, an addition circuit, and an optional amplifier circuit. The pulse density signal generator may also include rate transition circuits for ensuring that the pulse density input signals and the feedback pulse density signals are uncorrelated.

Disclosed herein is a method including receiving a stream of packets into a buffer, each packet having a processed video data portion and a page count portion, the processed video data portion being a result of a modulo operation performed on a word of video data, and the page count portion being a data page number on which the word of video data is to be placed. Each packet is read from the buffer, and an output packet including the video data portion and a data tag portion is generated therefrom. The data tag portion is associated with, but does not directly represent, the data page number where the word of video data of the processed video data portion or of video data of a processed video data portion of a next packet, is to be placed. Each data tag portion contains fewer bits than each corresponding page count portion.

A cellular radio architecture for a vehicle that includes a triplexer coupled to an antenna structure and including three signal paths, where each signal path includes a bandpass filter that passes a different frequency band than the other bandpass filters and a circulator that provides signal isolation between the transmit signals and the receive signals. The architecture also includes a receiver module having a separate signal channel for each of the signal paths in the triplexer, where each signal channel in the receiver module includes a receiver delta-sigma modulator that converts analog receive signals to a representative digital signal. The delta-sigma modulator includes an LC filter having a plurality of LC resonator circuits, a plurality of transconductance amplifiers and a plurality of integrator circuits, where a combination of one resonator circuit, transconductance amplifier and integrator circuit represents a two-order stage of the LC filter.

A receiver is configured to have two coherent receivers using two pieces of local oscillator of optical frequencies f11 and f12 close to optical frequency f1 of signal light, the two pieces of local oscillator being controlled to have a predetermined optical frequency spacing F, and a digital signal processor demodulating transmission data signal sequences based on outputs from the coherent receivers. When the frequency difference f1 of one of the two pieces of local oscillator from a virtual reference frequency f1 close to the optical frequency f1 of the signal light is set, the digital signal processor obtains the frequency difference f2 of the other of the two pieces of local oscillator by calculating f1F, inputs electric signals output from the two coherent receivers, and compensates the phase rotation caused in the electric signals by frequency differences f1 and f2.

Transport of differential signals is provided. In one aspect, a telecommunications system includes a first unit and a second unit. The first unit can calculate a differential signal from an original signal. The differential signal can represent a change in signal levels between constant time intervals in the original signal. The second unit can estimate the original signal from the differential signal received from the first unit over a communication medium.

A method for calibrating rates at which data is transmitted in a communication system. There is a short transmission utilizing a first set of communication parameters comprising first and second communication parameters. The first set of communication parameters are different from the second set of communication parameters used to create stable communication between the transmitter and receiver. The second set of communication parameters comprise first and second communication parameters. Then determining that there are substantially no errors associated with reception of the short transmission by the receiver. Then transmitting a long transmission utilizing a third set of communication parameters comprising first and second communication parameters. The first communication parameter of the third set is equal to the first communication parameter of the first set. The second communication parameter of the third set is equal to the second communication parameter of the second set.

An integrator including: a resistive element connected to an input terminal; an operational amplifier configured to receive, through the resistive element, an input signal that has been supplied to the input terminal; and a voltage regulator circuit connected to an intermediate node between the resistive element and the operational amplifier. The voltage regulator circuit has a first current source connected to the intermediate node, and a switch connected between the intermediate node and the first current source and selectively turning ON or OFF.

An integrator including: a resistive element connected to an input terminal; an operational amplifier configured to receive, through the resistive element, an input signal that has been supplied to the input terminal; and a voltage regulator circuit connected to an intermediate node between the resistive element and the operational amplifier. The voltage regulator circuit has a first current source connected to the intermediate node, and a switch connected between the intermediate node and the first current source and selectively turning ON or OFF.