Abstract: A free loop oscillator system including a set of successive delay elements connected in series forming a free-running loop oscillator, a set of taps disposed between the delay elements, a circuit for determining the speed of the free-running loop oscillator, and circuit for choosing a given tap in response to the speed of the free-running loop oscillator. Such a system may be implemented as a part of interval timer, a printer controller, a frequency synthesizer, an FM modulator, a digital-to-analog converter, or any other device which requires the availability of finely addressable signals since the taps disposed between the delay elements present signals much finer than any presently available clock.

Abstract: A radio control device includes a transmitter, in which a crystal type high frequency module equipped with a high frequency circuit corresponding to a frequency band of a carrier and a PLL high frequency module equipped with the high frequency circuit and a PLL circuit for controlling a frequency of the carrier depending on a phase difference between the carrier and a reference signal of oscillator are detachably mounted. Such construction permits the crystal type high frequency module and PLL high frequency module to be selectively used as desired and transmission data to be output by means of the carrier of a desired frequency set depending on the high frequency module.

Abstract: A method and apparatus for transmitting information over a wireless connection are provided. A correlation is established between a set of symbols and a set of pulse position/signal characteristic combinations. Thus, each symbol has a corresponding pulse position and a corresponding signal characteristic. The signal characteristic may be, for example, a particular frequency, amplitude or phase. To communicate a symbol, a device generates a signal in which a tone burst is sent during the pulse position that corresponds to the symbol. In addition, at least some portion of the signal reflects the signal characteristic that corresponds to the symbol. A receiving device determines the pulse position in which the tone burst was sent and determines the signal characteristic reflected in the signal. The receiving device then determines the symbol based on the pulse position and the signal characteristic. Synchronization is improved by generating synchronization tone bursts before each pulse position modulation frame.

Abstract: A Manchester code signal is used as a communication signal to be superimposed onto an operating current. The amplitude value in the plus direction with respect to an average current value is made larger than that in the minus direction, and the time width of an "H" level in one bit time is made smaller than that of an "L" level so as to establish the average current value into a low level. Accordingly, it is possible to make the average current value at the time of not-communication equal to that at the time of communication, and it is also possible to establish the average current value to a low level.

Abstract: A phase modulator circuit and method for generating an output signal having individually positionable edges is described. The phase modulator includes a programmable pulse generator, such as an interval counter, a delay, or a ring oscillator for producing the output signal, and a control value source, such as a memory, for delivering a sequence of control values to the generator. The control values determine the time between successive output pulses. A programmable interval counter includes a free running counter, the output of which is compared to a control value, preferably stored as a modulo data value, to generate an output pulse. A first programmable delay circuit includes a ring oscillator having plural delay lines for fine control of edge positioning. To fully synchronize the delay circuit to a coarse control interval counter, the clock input to the interval counter can be provided by the ring oscillator.

Abstract: A spread spectrum code pulse position modulated communication system is disclosed. The frequency spectrum of a transmitted signal is spread by encoding bits with a predefined spectrum-spreading codeword which is in accordance with regulatory requirements or other standardization decisions. When the predefined spread spectrum codeword is passed through a filter matched to the characteristics of the codeword, a peak is detected in the main lobe. A positive main lobe can indicate a binary value of "0" and a negative main lobe, associated with the inverse of the predefined codeword, can represent a binary value of "1". Additional information is conveyed by modulating the position of the center of the codeword within the symbol duration. In one embodiment, the position of the center of the codeword is varied among eight positions. Thus, eight signal states are available, and three additional bits may thereby be conveyed.

Abstract: A method and apparatus are shown for generating and transmitting very short and widely separated high frequency sine-wave pulses of electromagnetic energy into space. A transistor, a charging capacitor, and an inductor are coupled into a first series loop path to form a discharge circuit. A bias voltage source, the same charging capacitor, and a charging resistor are coupled into a second series loop path to form a recharging circuit. The bias voltage source is selected to be capable of biasing the forward conduction path of the transistor near its breakdown condition. An original information signal is sampled upon each occurrence of a periodic reference signal, and the transistor is then triggered into its breakdown or avalanche mode. The starting times of successive transmitted pulses are modified in accordance with a pulse position modulation protocol.

Abstract: A digital synthesizer for record circuitry of, e.g., a VCR, is supplied with digital samples representing a video signal. A calculator stage, responsive to the digital samples calculates a sequence of pulse periods defining a pulse duration modulated signal that represents FM modulation of a carrier by the video signal. An output sample generating stage operates on the sequence of pulse periods for generating a sequence of digital output samples which is converted in a digital-to-analog converter to the FM modulated video signal for subsequent recording on tape.

Abstract: A switched-inverter modulator for use in driving a load that comprises master and slave high voltage power supplies for providing output pulses that directly drive the load. A synchronized pulse generator provides pulse width tinting and synchronized amplitude commands to the master power supply. The timing pulse instructs the power supplies when to initiate high voltage and for what time interval. The analog waveform instructs the master power supply as to what high voltage level to obtain. The master power supply may have multiple slaves connected in parallel for additional current capacity. A low voltage DC capacitor bank is connected in parallel with each of the power supplies to supplement energy storage. Isolation resistors are coupled between outputs of the respective high voltage power supplies and the load to minimize temporary shorts from ringing back into the power supplies.

Abstract: A known method for transition encoding a logic signal involves: recording for each of a succession of window periods, the position of occurence of a first transition of the logic signal during that window by noting a count value reached at the time the first transition occurs; indicating the status of the logic signal after this first transition by appropriately setting a first bit; and indicating the occurence of a second transition during the same window period by the setting of a second bit. In order to avoid wrong encodings resulting from the occurence of a third transition within the same window period, the present invention provides for the effect delaying of any such third transition until the start of the next window period.

Abstract: A phase modulator circuit and method for generating an output signal having individually positionable edges is described. The phase modulator includes a programmable pulse generator, such as an interval counter, or a delay for producing the output signal, and a control value source, such as a memory, for delivering a sequence of control values to the generator. The control values determine the time between successive output pulses.

Abstract: A digital modulation process and apparatus for converting an input signal comprising a time variable series of sampling values, each of which sampling values remains constant within a fixed sampling period, into output signals representing a sequence of positive and/or negative pulses having a constant amplitude and a variable pulse width and frequency. The input signal and modulator parameters are supplied to a data processor. In order to reduce computing expenditures and at the same time achieve an increase in precision, by means of the computing system, the switch-on and switch-off points in time t.sub.se, t.sub.sa of the pulses as well as their operational signs are computed in one operation directly for each sampling period .DELTA.t.sub.k.

Abstract: A data transmission system includes a source of a data signal and a modulator, responsive to the data signal, producing a first modulated signal representing the data signal and a second modulated signal representing a signal 180 out-of-phase with the data signal. The first and second modulated signals are transported via a transmission channel. A first demodulator demodulates the transported first modulated signal and a second demodulator demodulates the transported second modulated signal. A subtractor, responsive to the first and second demodulators, produces a signal representative of the data signal.

Abstract: The present invention discloses a frequency stabilizing circuit used for a modulator that modulates an image signal including a synchronous signal into a pulse modulation signal. The frequency stabilizing circuit comprises a detecting device for detecting the synchronous signal included in the image signal that has not been modulated to output a pulse based on the detection, a pulse generating device for outputting a pulse by extracting a modulated signal outputted from the pulse modulator corresponding to the synchronous signal, and a feedback controlling device for increasing and/or decreasing a level of the image signal to be inputted to the pulse modulator in accordance with the difference between the pulse width of the pulse signal outputted from the detecting device and that of the pulse signal outputted from the pulse generating device.

Abstract: A digital synthesizer for record circuitry of, e.g., a VCR, is supplied with digital samples representing a video signal. A calculator stage, responsive to the digital samples calculates a sequence of pulse periods defining a pulse duration modulated signal that represents FM modulation of a carrier by the video signal. An output sample generating stage operates on the sequence of pulse periods for generating a sequence of digital output samples which is converted in a digital-to-analog converter to the FM modulated video signal for subsequent recording on tape.

Abstract: A method for increasing the bit rate of a data link is to select two additional 31-bit chip code patterns that are orthogonal to the present two chip codes, and to each other. This method will not require any more bandwidth that the present 10 MHz used. This method suggests that each of the four chip code patterns are assigned a two bit value i.e.: 00, 01, 10, 11. At present, the two correlated chip codes represent data in a pulse position method. No information is transferred by determining which of the two chip codes actually correlated. This new method suggests each of the four chip code patterns will still perform the pulse position modulation and also provide two additional bits of data. These additional two bits of data will up the data rate of the link by 100 percent. Alternatively, the data rate may be increased by coding the datasuch that a reduction in duty cycle is realized as well as an increase in the data rate.

Abstract: A pulse modulated infrared data communications link including a transmitter and receiver in which the data to be sent is encoded as a biphase modulated signal having bit-cell and mid-cell transitions. Each transition is encoded as a narrow pulse in a pulse modulated signal. The pulse modulated signal is used to activate an infrared optical transmitter for generating pulsed optical signals. At a receiver, an optical detector converts pulsed optical signals into pulsed electrical signals. The pulsed electrical signals are amplified and filtered and evaluated by a comparator to generate a pulsed digital signal. The pulsed digital signal is processed by a logic circuit to generate a biphase encoded signal for transmitting on a serial data line.

Abstract: There are provided a communication system and an apparatus for modulating a communication signal into a chirp signal and executing the communication. In the system, a signal to be transmitted is input, a predetermined analog pattern signal is added to the input signal and is pulse position modulated, the modulated signal is converted into the chirp signal, and the chirp signal is output onto a transmission path. The converted chirp signal can be also converted into an optical signal and the optical signal can be also output onto the transmission path. After the analog or digital input signal was pulse position modulated, by converting the modulated signal into the chirp signal, the analog signal can be also transmitted and received as a chirp signal. Thus, the communication reliability can be assured without being influenced by disturbance noises or irrespective of a limitation of a transmission electric power of the transmission path.

Abstract: In a digital remote-sensing system, in which the time intervals between pulses are modulated according to the value of the parameter being measured, an overly sensitive sensing element 30 may generate a pulse outside of the desired "time window", which might then be misinterpreted. To avoid this, the sensitivity of such a digital sensing element 30, generating a frequency-modulated signal, can be reduced without intrusion into the actual sensor 32, by "thinning" the output pulses of the digital sensing element 30 with pulses of constant frequency. In the case of a sensor which, after receipt of a start-pulse, generates one or more measurement pulses, this is accomplished by specifying a part of the pulse-period in a timing stage 44, which operates in dependence on a constant-frequency auxiliary oscillator 46. The timing stage's output signal makes conductive a gating circuit 36, disposed between sensing element 30 and a downstream frequency divider 38-42, which generates the measurement pulses.

Abstract: In the pulsed FM system, the input signal is first modulated into the pulse FM signal. Thereafter, this pulse FM signal is modulated into the pulsed FM signal by the frequency divider. This pulsed FM system is suitable to CATV.

Abstract: A digital 2B1Q transmitter utilizes a dual modulator to generate a 2B1Q coded output by summing two binary modulated vectors in a 2:1 weighting ratio, allowing one modulating envelope generator to drive the dual modulator. The modulating envelope is coded in a 1-bit pulse density modulation (PDM) format, permitting the use of simple gating functions in performing the modulation function. The rising half of the transmit pulse is stored in the envelope generator, while the trailing half is derived from the rising half using the "1-x" function; this allows part of the summing functions to be reduced to OR gates.