Abstract: A pulse frequency modulation oscillating circuit includes a reference voltage generator for generating a first reference voltage and a second reference voltage, a first comparison circuit for comparing a state signal with the first reference voltage, a second comparison circuit for comparing the state signal with the second reference voltage, an output circuit for outputting a pulse frequency modulation signal according to an under-voltage signal, and signals outputted from the first comparison circuit and from the second comparison circuit, a mode generation circuit for generating the state signal, and a mode decision circuit for outputting inverse signals of the signals outputted from the first comparison circuit or signals outputted from the output circuit to the mode generation circuit according to the pulse frequency modulation signal, the under-voltage signal, and the signals outputted from the first comparison circuit and from the second comparison circuit.

Abstract: A tri-state pulse density modulator includes a first switch device coupled to a high voltage, and a second switch device coupled to a low voltage. An adder receives a pulse density modulation (PDM) input signal and a latched input signal to generate an output sum signal and a carry signal. A latch module coupled with the adder latches the output sum signal with a clock signal to generate the latched input signal. A control circuit module responsive to the carry signal for selectively turns off the first and second switch devices to generate the PDM output signal at a tri-state voltage between the first and second voltages, or turns on the first or second switch device to generate the PDM output signal at the first or second voltage, respectively. Thus, the PDM output signal only switches between the tri-state voltage and either the first voltage or the second voltage.

Abstract: A modulation method, referred to as dual phase pulse modulation (DPPM), represents digital data as a series of high and low pulses whose widths represent groups of M data bits, with both the high and low pulses representing successive M-bit groups. Each of the 2M possible data values for a group of M data bits uniquely corresponds to one of 2M distinct pulse widths. This modulation method is essentially clockless, with data being decoded from a signal by detecting each pulse's width with respect to the last transition. Power consumption is reduced by having M data bits represented for each pulse transition, and by using both the high and low pulses to represent data.

Abstract: The invention is a method for pulse position modulating signals which are synchronized to clocked bit periods using a clock comprising the steps of generating two, three or n signals to mark the presence of digital ones during corresponding n time slots occurring during the same bit period. The two, three or n signals are combined into a single data channel to utilize abrupt phase changes of pulses in a carrier signal at a carrier frequency, the phase changes having a very short duration to mark the presence of digital ones only. The combination of the n signals into a single data channel comprises gating each of the n signals in a sequence of serially delayed time slots corresponding to each of the n signals during a portion of the same bit period in the single data channel during time positions reserved for unexpressed zeroes.

Abstract: In order to provide a high-speed-pulse polarity modulation circuit for realizing low power consumption and miniaturization and reducing noise occurring at a middle level which is a baseline for a bipolar pulse, a modulation circuit for converting a unipolar pulse into a bipolar pulse in accordance with a value of input data is structured such that differential transistor pairs are double stacked, and one of the differential transistor pairs in an upper stage outputs polarity modulation pulses, and a middle potential between logic high and low is applied to the gates of the other differential transistor pair the gates of which are coupled together.

Abstract: A high speed passband phase modulation apparatus and method are provided. In the phase modulation apparatus, an RF phase shifter modulates a phase of a local signal that is generated in a VCO according to a digital input. The RF phase shifter is controlled by a phase-controlled loop so that a baseband phase shifter is phased locked to a modulation reference signal from the local signal and a reference clock signal according to the digital input. The phase-controlled loop phase-locks using the modulation reference signal so that the phase-modulated signal generated in the RF phase shifter has a phase value according to the digital input.

Abstract: A radio communications system in which a desired signal can be accurately discriminated from interfering signals, even when signals from a plurality of transmitters are received simultaneously, in which a transmitter communicates information using signals that are repeated over predetermined periods. A pulse generator generates pulses having a predetermined repetition period based on an information bit to be communicated, and the pulses generated by the pulse generator are transmitted. A pulse amplitude altering unit controls the amplitude of the pulses to be transmitted in accordance with a predefined pattern under the control of a control unit.

Abstract: The operating method is based on the simultaneous use of FM and AM and is distinguished by passing through a number of steps which are used to find an optimum frequency for the AM and, in addition, to define an optimum AM level. An electronic ballast which has a memory module which can be overwritten is used for implementation.

Abstract: A frequency synthesizer is provided having a fractional-N control circuit and method that can selectively apply any fractional ratio to a frequency divider within the feedback loop of a PLL. A special digital delta-sigma modulator can be implemented as the control circuit and can receive any arbitrary numerator and denominator value, or their arithmetic combination, or a positive and negative vector values used by the modulator to achieve an average fractional division. Both the numerator and denominator (or the positive and negative vectors) can be chosen based on any integer value to achieve a more optimal, higher frequency resolution and efficient fractional-N control circuit and methodology thereof.

Abstract: A dual-port modulator comprising a first Phase Locked Loop (‘PLL’) (15) including a first Voltage Controlled Oscillator (‘VCO’) (10), a first variable frequency divider (20), a first multi-accumulator sequence generator (21) responsive to a phase modulation signal for controlling the division ratio (1/Nr) of the first variable frequency divider, a first phase detector (30) responsive to the relative phases of the reference signal and the first frequency divider signal for producing a first control signal through a first low pass filter (40).

Abstract: Methods and systems for generating a variable spacing pulse position modulated (VSPPM) signal for transmission across an ultra-wideband communications channel. The variable pulse position modulated spread spectrum signal is created by encoding every M input data bits from an input data stream into a symbol consisting of Nc chips. Each chip is divided into 2M sub-chips and each sub-chip is further divided into Np time slots. A pulse is transmitted for each chip in the symbol. During each chip period, the pulse is placed in the sub-chip corresponding to the binary M-tuple (or symbol) value. A time hopping code sequence consisting of Nc elements with a one-to-one chip association is then applied to each symbol so that the position of each pulse is shifted to the appropriate time slot that corresponds to the time hopping code value.

Abstract: A method and apparatus for modulating a pulse signal with a bit stream is disclosed. The pulse signal is modulated by selectively inverting and delaying signal pulses within the pulse signal responsive to bits within the bit stream.

Abstract: A pulse modulator comprises a delay arrangement for receiving a first sequence of pulses and for delaying each received pulse several times to obtain a plurality of sequences of pulses having different phases. The pulse modulator further comprises a selection component for receiving from the delay arrangement a plurality of sequences of pulses having different phases, for receiving a modulating signal, wherein each possible value of the modulating signal is associated to one of the different phases, for selecting for each pulse of the first sequence of pulses a pulse of the respective sequence of pulses which sequence of pulses has a phase associated to a current value of the modulating signal, and for outputting the selected pulse as part of a pulse position modulated sequence of pulses. The invention relates equally to a modulating system comprising such a phase modulator and to a corresponding method.

Abstract: Method and apparatus for time aligning first and second signals. The second signal is modulated by the first signal to provide a third signal. Frequency components of the third signal are then determined, the frequency components being indicative of time alignment between the first and second signals. The method and apparatus is particularly suitable for converting a Non-Return-to-Zero data signal to a Return-to-Zero data signal by modulating the Non-Return-to-Zero data signal with a Return-to-Zero pulse signal. The method and apparatus provides for the Non-Return-to-Zero data signal and the Return-to-Zero pulse signal being correctly time aligned in an automated manner without human intervention.

Abstract: A spread spectrum transmission apparatus includes, a chip clock generation section which outputs a chip clock in one frame formed of M+L?1 chips, a frame clock generation section which outputs a frame clock synchronized to frame occurrence timing, SS-PPM signal generation sections each of which inserts a pseudonoise code sequence corresponding to one period from some of M chips located at a head of a frame based on K-bit transmission data and generates an SS-PPM signal, delay sections which respectively delay N SS-PPM signals respectively by determined delay quantities, and a multiplexing section which adds up all of outputs respectively of the delay units and generates a multiplexed SS-PPM signal.

Abstract: A modulated ultra wideband pulse generation system is provided. The system comprises a pulse waveform generator circuit operable to generate an on-off pulse waveform, and a modulating circuit operable to receive a modulating signal and to modulate the on-off pulse waveform in response to the modulating signal. Further embodiments of the invention comprise a variable bandwidth circuit operable to alter the bandwidth of the pulses comprising the on-off pulse waveform. Various embodiments of the invention comprise on-off keying modulation, pulse position modulation, and pulse phase modulation.

Abstract: Disclosed is a noncoherent pulse position and phase shift keying (PPPSK) transmission/reception system and a transmission/reception signal processing method therefor. Transmission system has an information generation unit for generating information data; a modulation unit for deciding a phase and a timing position corresponding to generated information data; and a wavelet generation unit for generating a wavelet based on the decided phase and timing position, and the reception system has an offset unit for mixing the reception signal with a high-frequency component corresponding to a center frequency of a transmission frequency band and offsetting a high frequency of the reception signal; a demodulation unit for generating at least one reference signal based on a previous signal precedingly received with respect to the reception signal and mixing the reference signals and the reception signal; and a decision unit for deciding information data corresponding to the reception signal based on mixing results.

Abstract: A transceiver and transmitter are shown. A baseband processor receives a signal for transmission. It converts the signal into amplitude and phase polar components. Each component is then processed—the phase component through a wideband phase modulator and the amplitude component through a wideband amplitude modulator, and the components are then recombined for further processing or transmission.

Abstract: An optical processor for controlling a phased antenna array uses a frequency-shifted feedback cavity (FSFC), which includes a traveling-wave cavity. The FSFC incrementally delays and incrementally frequency shifts optical signals circulating in the traveling-wave cavity. Optical signals coupled out of the FSFC are separated by frequency, hence by delay, and processed to control either or both transmit and receive beam-forming operations. The FSFC provides a receiver with multiple receive signals which have incremental values of frequency. Each frequency corresponds to an incremental time sampling of optical signals input into the FSFC. Transmit signals coupled out of the FSFC have frequency and phase relationships that result in short time-domain pulses when combined. Controlling modulation and frequency of the transmit signals achieves carrier interference multiple access, a new type of spread-spectrum communications.

Abstract: Disclosed is a noncoherent pulse position and phase shift keying (PPPSK) transmission/reception system and a transmission/reception signal processing method therefor. Transmission system has an information generation unit for generating information data; a modulation unit for deciding a phase and a timing position corresponding to generated information data; and a wavelet generation unit for generating a wavelet based on the decided phase and timing position, and the reception system has an offset unit for mixing the reception signal with a high-frequency component corresponding to a center frequency of a transmission frequency band and offsetting a high frequency of the reception signal; a demodulation unit for generating at least one reference signal based on a previous signal precedingly received with respect to the reception signal and mixing the reference signals and the reception signal; and a decision unit for deciding information data corresponding to the reception signal based on mixing results.

Abstract: A mud pulse telemetry technique that uses a number of bits per interval based on parameters of the pulse position modulation system in order to reduce data transfer time in a pulse position modulation system. More particularly, depending on parameters of the pulse position modulation such as the minimum-time and the bit-width, it may be possible to decrease overall transmission time by splitting values having a larger number of bits into multiple transmissions with each transmission having a smaller number of bits.

Abstract: Method and system are disclosed for automated calibration of the VCO gain in phase modulators. The method and system of the invention comprises synthesizing, in a phase modulator, a signal having a given output frequency using a controlled oscillator having a frequency control input, a modulation input, and a feedback loop. A frequency control signal is applied to the frequency control input, and gain variation of the controlled oscillator is compensated for outside of the feedback loop via the modulation input. The method and system of the invention may be employed in any telecommunication system that uses phase and amplitude modulation, including EDGE and WCDMA systems.

Abstract: In an embodiment, the present invention is directed to a PLL phase demodulator that utilizes feed-forward error correction. The feed-forward error correction may occur by calibrating an equalizer to possess a transfer function that emulates the modulation response curve of the VCO of the PLL of the PLL phase demodulator. In operation, the equalizer may receive the filtered and integrated version of the error signal produced by the phase detector of the PLL. The equalizer filters the received signal according to the calibrated transfer function. The output of the equalizer is provided to a adder to combine the equalized signal with the error signal produced by the phase detector. A similar arrangement including a suitably calibrated equalizer may be utilized to address phase tracking error in a PLL frequency demodulator.

Abstract: A method and drive unit for controlling a modulator (128) in which the working point of the modulator (128) is regulated using a regulating circuit (124) in such a way that the working point is stable in relation to the transmission characteristic curve of the modulator (128) for a long time and under different operating conditions.

Abstract: A modulated ultra wideband pulse generation system is provided. The system comprises a pulse waveform generator circuit operable to generate an on-off pulse waveform, and a modulating circuit operable to receive a modulating signal and to modulate the on-off pulse waveform in response to the modulating signal. Further embodiments of the invention comprise a variable bandwidth circuit operable to alter the bandwidth of the pulses comprising the on-off pulse waveform. Various embodiments of the invention comprise on-off keying modulation, pulse position modulation, and pulse phase modulation.

Abstract: A pulse density modulator unit transforms an N-bit input signal representing an input value, into an output digital signal having a digital pulse density which is a linear function of the input value. The pulse density modulator unit includes a first pulse density modulator which produces a binary signal representing a multiplication factor as a pulse density. It further includes a combination module which receives the input signal, the binary signal from the first pulse density modulator and an offset control signal. The combination module produces a combined signal which, on average, represents the product of the input signal and the amplification control signal, offset by an amount dependent upon the offset control signal. A second pulse generator uses the combined signal to generate the output digital signal. The combination module may be a selector.

Abstract: Method for controlling the operating range of a modulator, and an associated drive unit, the operating range of the modulator being controlled via a control circuit such that the operating range is stable over a long period of time and in different operating conditions, relative to the transmission characteristic of the modulator.

Abstract: The present invention provides a digital signal encoding apparatus for encoding one-bit signals of a plurality of n (n≧2) channels which is modulated in the delta-sigma manner, which includes a channel compositor 6 for compositing scrambled data supplied from the scrambler L 4 and scrambled data supplied from the scrambler R 5, a phase modulator 7 for phase-modulating composited data supplied from the channel compositor 6, a SYNC signal adding and correcting unit 8 for receiving SYNC timing signals generated at and supplied from a SYNC timing generator 9 and inserting SYNC signals into phase-modulated one-bit audio signal data supplied from the phase modulator 7 to generate SYNC patterns and correct the SYNC patterns, and an information data adding unit 11 for adding information data which is related with one-bit audio signals to phase-modulated one-bit audio signal data via the SYNC signal adding and correcting unit 8 by rearranging data of inverted phases thereof on the basis of two channel unit.

Abstract: A wireless digital transmission and receiving method combines phase reversal keying with pulse position modulation. Modulation of a transmitted signal implements pulses that are of extremely short duration to indicate ones and zeros. These pulses can be as narrow as one cycle of the carrier frequency. As such, they often appear as missing cycles or pulses in a sequence of carrier cycles. The method synthesizes a sideband with no carrier or other sidebands from the carrier of an input signal. This synthesized sideband is represented by a broad sinx/x spectrum with a principal power peak at the modulated frequency and numerous weaker peaks of varying frequencies and peak levels. The time duration of these smaller peaks is such that they have negligible mean power levels. Thus, the synthesized signal can withstand the degradation caused by multipath interference and fading. The weaker peaks also do not cause measurable interference with other communications devices.

Abstract: A light-controlled light modulator can achieve high-speed, low-loss wavelength conversion. Continuous light with a wavelength &lgr;j is launched into an MMI coupler via a port, and is split into two parts by the MMI coupler, which are led to a loop-type interferometer. In the loop-type interferometer, the two parts travel separately around the loop as clockwise traveling light and counterclockwise traveling light, are combined by the MMI coupler again via a filter-equipped phase modulator, thereby being emitted to the port. In this state, signal light &lgr;i(s) with a wavelength &lgr;i is launched into the filter-equipped phase modulator via a port. Even when the wavelength &lgr;i of the signal light &lgr;i(s) is equal to the wavelength &lgr;j of the wavelength converted output light, the wavelength conversion can be achieved with preventing noise from being mixed into the output light emitted from a port.

Abstract: A digital data modulator includes a source of a plurality of digital data signals having a common data bit period. A plurality of encoders each encode a corresponding one of the plurality of digital data signals using a variable pulse width code having edges occurring in respective non-overlapping intervals within the data bit period. A plurality of pulse signal generators each generate respective pulses representing the edges of the corresponding one of the encoded plurality of digital data signals. A carrier signal generator generates a carrier signal having carrier pulses corresponding to the respective pulses.

Abstract: A pulse density modulator for performing a modulation process by changing a pulse density per unit time. The pulse density modulator includes a counting circuit for counting supplied clock signals, a first waveform data generating circuit for synthesizing count data outputted from the counting circuit to generate basic waveform data, a second waveform data generating circuit for synthesizing the basic waveform data outputted from the first waveform data generating circuit to generate pulse density modulated waveform data corresponding to digital data supplied externally, a clock correction signal generating circuit for generating a clock correction signal indicating the phase of an unequal cycle component included in the clock signals, and a waveform data correcting circuit for correcting the pulse density modulated waveform data based on the clock correction signal.

Abstract: A chaotic carrier pulse position modulation communication system and method is disclosed. The system includes a transmitter and receiver having matched chaotic pulse regenerators. The chaotic pulse regenerator in the receiver produces a synchronized replica of a chaotic pulse train generated by the regenerator in the transmitter. The pulse train from the transmitter can therefore act as a carrier signal. Data is encoded by the transmitter through selectively altering the interpulse timing between pulses in the chaotic pulse train. The altered pulse train is transmitted as a pulse signal. The receiver can detect whether a particular interpulse interval in the pulse signal has been altered by reference to the synchronized replica it generates, and can therefore detect the data transmitted by the receiver. Preferably, the receiver predicts the earliest moment in time it can expect a next pulse after observation of at least two consecutive pulses.

Abstract: A system and associated methods that use separate paths to send amplified data. The method expands, or amplifies, the amount of data that can be transmitted over a dedicated bandwidth-limited communications medium by using a first channel for transmitting clock synchronization pulses and transmitting the data as pulse position modulated (PPM) data over a second separate bandwidth-limited communication channel. Data for transmission is encoded by determining if the period of a pulse encroaches into the frame of the subsequent pulse. In response to a determination of encroachment, one or both of the pulses are inverted and time shifted to eliminate the encroachment. In the event that inversion of one or both of the pulses does not eliminate the encroachment, a blank is inserted between the two pulses.

Abstract: A spiking neuron circuit providing a spiking output signal in response to an input current that causes a first capacitor to charge to a threshold voltage. In response to achieving such threshold, an output terminal is connected to a voltage, illustratively VDD, for a period determined by an applied voltage, Vpw. Rapid switching of the output to its spiking level is achieved using a positive feedback path, and deactivation of such feedback rapidly terminates the spiking period.

Abstract: A transceiver has a pulse position modulation (PPM) encoder, automatic gain control (AGC) circuit and timing recovery circuit. The PPM encoder illustratively has a frequency divider, slot selector, and mixer. The frequency divider divides the frequency of a clock signal to which the data of the non-return to zero (NRZ) signal are aligned to produce a half frequency clock signal. The slot selector selects pulses of the clock signal and the half frequency clock signal depending on logic values of the NRZ signal and a control signal to produce first and second slot selected signals. The mixer mixes the first and second slot selected signals to produce a PPM signal of the NRZ signal. The AGC circuit illustratively has a variable gain amplifier, a hysteresis comparator, an event detector, a timer, and a counter. The variable gain amplifier amplifies the PPM signal using a dynamically adjusted gain that depends on an inputted digital control value.

Abstract: A method and apparatus for pulse position modulation begins when a digital data stream is received. The encoding process continues by obtaining a set of bits from the digital data stream and modulating the set of bits into a pulse having a pulse width. Next, a transition edge of the pulse is positioned at one of a plurality of time intervals within a time chip based on the set of bits, wherein the pulse width is greater than each of the plurality of time intervals.

Abstract: In a subscriber line interface circuit connected to a telephone line having a high potential wire and a low potential wire, an arrangement for generating a signal for determining the line voltage comprises means (7, 10, 11) for alternately charging a capacitor (6), by means of a first DC current, to a first voltage, and discharging the capacitor (6), by means of a second DC current, to a second voltage. Hereby, a sawtooth wave having an amplitude corresponding to the difference between the first and second voltages is produced. This sawtooth wave is converted to a pulse train related to the line voltage, from which the line voltage can be determined.

Abstract: Multiple pulse width and position modulation methods and systems use multiple pulse width and position modulation (PWPM) circuits driven from the same system clock and video data to provide multiple video pulses per clock period. The multiple pulse width and position modulation methods and systems separately provide extremely fine halftone structures from n-bit per pixel video data words. The halftone structures can be provided without the need for extremely high resolution raster output scanners, associated optics and high speed electronics. The multiple pulse width and position modulation system (PWPM) can produce video pulses of variable width and position within a pixel period with extremely high addressability. The pulses output from multiple, independent pulse width and position modulation (PWPM) channels can be combined to form structured multiple video pulse patterns within the video clock or pixel period from a given n bit video data word.

Abstract: An output signal pulse width error correction circuit and method wherein errors in a data signal conforming to a communications protocol having a prescribed duty cycle are corrected by monitoring a duty cycle of the data signal, comparing the duty cycle to a duty cycle reference voltage corresponding to the prescribed duty cycle, and adjusting a pulse width of the data signal to conform to the prescribed duty cycle of the protocol. An embodiment is shown that low pass filters the input data signal to introduce greater slope to the input data signal which is then compared to a pulse width control voltage in order to generate an output data signal. The pulse width control voltage is produced by integrating the output data signal to obtain an average value corresponding to the duty cycle of the output data signal and comparing the average value to a duty cycle reference voltage corresponding to the prescribed duty cycle for the communications protocol.

Abstract: A method and apparatus for encoding data into a pulse pattern begins by encoding header data based on a first pulse encoding convention to produce a header pulse pattern. The resulting header pulse pattern occupies multiple time chips and indicates that subsequent pulse pattern signals are valid. After generating the header pulse pattern, a set of bits of a stream of data is encoded based on a second pulse encoding convention to produce a data pulse pattern. The data pulse pattern occupies at least one time chip. The first and second encoding conventions are used to ensure that the header data and data are encoded in distinguishing manners such that both can be accurately decoded. Such conventions include using a predetermined pulse pattern to represent the header data, which is only used for the header data.

Abstract: A system for, and method of, generating a spread spectrum code position modulated waveform and a wireless local area network (LAN) containing the system or the method. The system includes: (1) a spread-spectrum encoder that receives and encodes portions of an information signal with a multi-chip code having a predetermined length to create therefrom a stream of sequences, each of the sequences having the predetermined length and (2) a transmitter that periodically transmits the each of the sequences at a time interval that differs from the predetermined length, a data rate of transmission of the information signal thereby allowed to increase.

Abstract: A system for receiving information encoded in a train of pulse position modulated signals and then decoding the pulse train to produce amplitude modulated signals representing the original information includes a circuit for detecting the beginnings of successive PPM signals, a one-shot multivibrator responsive to the beginnings of the PPM signals for producing pulse width signals whose duration varies in accordance with the received intelligence, and an R-C low pass output circuit coupled to the output of the multivibrator to produce amplitude modulated output voltage waves. The R-C circuit has a time constant substantially greater than the unmodulated period between PPM pulses, and produces a rising voltage that spans the time duration of an associated high voltage level square pulse and whose decaying voltage level varies in amplitude in accordance with the maximum voltage attained at the output of the R-C integrator by the trailing edge of the associated high voltage level pulse.

Abstract: A spread spectrum pulse position modulation/demodulation system which receives an input signal including frames and which includes first and second pulse position modulators. The first pulse position modulator modulates each frame by inserting a first pseudo noise code into a selected slot of each frame according to the input signal to generate a first spread spectrum pulse position modulating signal. The second pulse position modulator modulates each frame by inserting a second pseudo noise code into a selected slot of each frame according to the input signal to generate a second spread spectrum pulse position modulating signal. An adder adds together the first and second spread spectrum pulse position modulating signals to generate a third spread spectrum pulse position modulating signal. This third spread spectrum pulse position modulating signal may be transmitted by a radio transmitter, and then received by a radio receiver.

Abstract: A method and apparatus for encoding a bit sequence as a symbol, suitable for transmission over POTS wiring, are described. The symbol has a duration indicative of the bit sequence, this time duration be determined by first and second delimiters. The method commences upon the receipt of a bit sequence at an encoder. Thereafter, a symbol, having a duration indicative of the bit sequence, is identified. The symbol is characterized in that it includes a buffer portion and an encoding portion. The buffer portion is of sufficient duration to allow reflections, generated by propagation of the first delimiter of the symbol on the POTS wiring, to decay to a predetermined level before propagation of the second delimiter.

Abstract: A power distribution system (12) is provided in radar apparatus to distribute power from a 270 VDC source (60) through an intermediate power converter (70) and very high frequency (VHF) regulator/modulator units (80). Bus conductors (71,74) interconnect the source, the intermediate power converter, and the VHF units. Capacitors (71, 76) are connected to the bus conductors on the input and output sides of the intermediate power converter. Each VHF unit supplies modulating pulses to RF amplifiers (82) of an AESA array of the radar apparatus.

Abstract: A spread spectrum pulse position modulation/demodulation system which receives an input signal including frames and which includes first and second pulse position modulators. The first pulse position modulator modulates each frame by inserting a first pseudo noise code into a selected slot of each frame according to the input signal to generate a first spread spectrum pulse position modulating signal. The second pulse position modulator modulates each frame by inserting a second pseudo noise code into a selected slot of each frame according to the input signal to generate a second spread spectrum pulse position modulating signal. An adder adds together the first and second spread spectrum pulse position modulating signals to generate a third spread spectrum pulse position modulating signal. This third spread spectrum pulse position modulating signal may be transmitted by a radio transmitter, and then received by a radio receiver.

Abstract: The disclosure relates to a method of reception of signals from at least two transmitters (RCi), wherein for each transmitter the data ("0", "1") are represented by the time interval (T0i, T1i) between two consecutive pulses transmitted by this transmitter, said time intervals and the pulse widths (Tpi) being characteristic of each transmitter, and wherein said method includes the following steps: reception of a resultant signal that is the sum of the signals from by said transmitters; determination of the parameters of said resultant signal, these parameters including the width and spacing of the pulses; analysis of said parameters and assignment of a data item to one of said transmitters. The invention also concerns a receiver device, a remote controller, and a system of reception. The invention is applicable notably in the field of television and video.

Abstract: A method for modulating a radio signal has the steps of: predetermining a first time interval so as to define a data word; generating a synchronization pulse, the synchronization pulse initiating a single data word having a length of the predetermined first time interval; and generating a single data pulse within the data word after a second time interval with respect to the synchronization pulse, the length of the second time interval defining at least one character. Defining at least one character by a single data pulse after a second time interval with respect to the synchronization pulse enhances an energy efficiency of the transmitted radio signal while mitigating a duty cycle thereof.

Abstract: A method and apparatus for generating a modulated signal include a pulse modulation source (215), a pulse modulator (20) for modulating a pulsed signal, a high efficiency power amplifier (230) for amplifying the modulated pulsed signal, and a harmonic reduction filter (240) for passing the switching frequency of the pulsed signal as the RF carrier. The pulse modulation source (215) accepts baseband inphase and quadrature signals and determines phase values and duty ratios for modulating the pulsed signal. The pulse modulator (20) phase modulates and duty cycle modulates the pulsed signal before it is amplified and filtered. A quadrature demodulator (260) produces baseband inphase and quadrature feedback signals for increased linearity.