Abstract: The invention concerns a method and a system for ensuring successful setup of calls in a telephone exchange system comprising a local exchange (LE), an access node (AN) and a concentrating V5 interface (V5) connecting the access node (AN) to the local exchange (LE). In the method, the concentrating interface (V5) is divided into two or more parts.

Abstract: A method and apparatus to produce a pulse width modulated (PWM) signal from pulse code modulated (PCM) data. In one embodiment, a crossing point of an analog signal with the ramp portion of a sawtooth waveform is approximated by first extrapolating, or projecting, a line between two adjacent sample points across other sample points to produce an estimate of the crossing point. A magnitude difference between a crossing point of the extrapolated line and a sample point magnitude on each side of the crossing point is determined. The magnitude difference, multiplied by an empirically determined constant, is added to the estimate. A PWM signal is then produced using the estimate for the crossing point.

Abstract: An audio data transmission and recording system and a recording medium according to the system. Gaps in the audio data are used to control the addition of spectrum-diffused data to the audio data. The gaps are also used to control demodulation of the spectrum-diffused data.

Abstract: A method according to the invention includes the steps of sending one or more upstream signals, such as voice signals, as pulse code modulated data (201) without packet headers using an upstream cable protocol and sending one or more downstream signals, such as voice signals, as pulse code modulated data (405) without packet headers using a downstream cable protocol.

Abstract: A PWM signal generator allowing a desired combination of cycle and duty to be reliably generated from cycle and duty set values received from a CPU is disclosed. A cycle comparator compares a counted value of a timer to a cycle set value and a duty comparator compares the counted value to a duty set value. A PWM output circuit outputs a PWM signal that is set and reset depending on a combination of a cycle coincidence signal and a duty coincidence signal generated from the cycle and duty comparators, respectively. A transfer controller controls transfers timing of cycle and duty set values while monitoring the cycle coincidence signal and the write timing of the cycle and duty set values.

Abstract: A frequency estimator for estimating the frequency of a digital input signal (x(k)) includes a phase detection device (2) for determining the phase (&phgr;(k)) of the input signal (x(k)), a differentiator (3) for generating the phase difference (&phgr;diff1(k)) between adjacent samples of the phase (&phgr;(k), &phgr;(k-1)) and a filter (4) for averaging the phase difference (&phgr;diff(k)) and having a trapezoidal pulse response (hM(k)). The trapezoidal pulse response (hM(k)) is generated by superimposing a first triangular pulse response with a second triangular pulse response which is offset in time with respect to the first triangular pulse response.

Abstract: A method, a device, and an interface for transmitting data between at least two subscribers, at least one first subscriber transmitting a pulse-width-modulated data signal. The at least second subscriber for its part transmits an asynchronous data signal, which is composed of binary signals, both subscribers transmitting the data, in each case, at a different, specifiable transmission rate. In this context, one of the two transmission rates, in particular that of the second subscriber, is adjusted, in particular increased, so that the pulse-width-modulated data signal of the first subscriber is simulated by a number of the binary signals of the asynchronous data signal.

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 transponder (1) for the contactless communication with a base station (2) comprises an antenna resonant circuit (10) for receiving a modulated HF signal (5), signal processing means (13) for processing the modulated HF signal and for supplying a data signal (DS) and a clock signal (CLK), and data processing means (23) arranged to receive the data signal (DS) and the clock signal (CLK) and to process the data signal (DS), the clock signal (CLK) defining the processing speed of the data processing means (23) and the data processing means (23) being arranged to receive reset information (RI) for terminating the processing of the data signal (DS), the transponder (1) further comprising a frequency detector (31) arranged to receive the clock signal (CLK) and adapted to compare the frequency of the clock signal (CLK) with at least one limit frequency (fG1) and to supply the reset information (RI) to the data processing means (23).

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: In a first controller that runs a first control algorithm and a first interrupt service, wherein the first control algorithm includes a first series of commands repeatedly executed in sequence, wherein the first interrupt service performs a second series of commands when the first interrupt service is triggered, wherein the first controller includes a first free running counter with a counter timer value that repeatedly increments and resets when the counter timer overflows, a data communication method comprising the steps of: in each sequential execution of the first series of commands: reading a data signal to be transmitted; responsive to the data signal, computing an on-time; setting a first edge of a serial transmission signal; and loading a register with a value equal to a sum of the first counter value and the on time; independent of the first series of commands: comparing the first counter value to the register value; when the first counter value equals the register value, triggering the first interru

Abstract: In a receiver, a system and method are disclosed for providing improved detection of data from a transmitted sequence of pulse width modulated (PWM) pulses. The disclosed system includes a pulse detector having an adjustable critical duty cycle for distinguishing between first and second pulses based upon their respective long and short duty cycles at which they are received. The disclosed system further includes an element which determines the duty cycle of the received pulses and an element which adjusts the critical duty cycle based on the duty cycle which is so determined. The duty cycle may be determined by determining the correspondence between information obtained from an initial pulse sequence and reference information at the receiver. In the disclosed method, the duty cycle of pulses in an initial sequence is first determined and then checked against a predetermined limit. If the duty cycle falls outside the limit, the critical duty cycle is adjusted prior to further pulses being detected.

Abstract: A communication control apparatus, provided with an echo back comparison detecting unit (30) detecting something abnormal of communication data from itself or an abnormal state generated at a data line (4), by starting transmission of communication data from itself following a detection of a line state detecting unit (29), when the line state detecting unit (29) detects that transmission of communication data from another communication apparatus to a data line (4) is started in a transmission permissible section, and by taking in communication data at the data line (4) and by comparing it with communication data having been transmitted from itself, and further provided with a transmission mark generating unit (23) shortening a bit width of data indicating a start of communication data transmitted from itself, prevents an abnormal waveform from being transmitted to the data line (4) because accuracy of echo back comparison is improved and delay tolerance of the data line (4) is eased.

Abstract: A method and device for generating a constellation of Pulse Code Modulation (PCM) levels to represent digital data in a communication system. The constellation of Pulse Code Modulation levels are selected to have a total number of PCM levels and an upper power limit that optimizes noise performance. PCM levels are selected to increase the minimum spacing between PCM levels as great as possible while staying within the upper power limit for a constellation having a desired number of PCM levels. To minimize the power level of the selected constellation, constellation points are selected starting from PCM levels at linear values near zero to PCM levels at higher linear values. To improve noise performance, the number of occurrences of the minimum distance between PCM levels is also reduced without exceeding the upper power level. To reduce occurrences of the minimum distance between constellation points, PCM levels at the minimum distance from the previously selected PCM level may be skipped.

Abstract: An apparatus and method for measuring a characteristic pulse width of a data channel for a data handling device, with particular application to an HDD having an automatic gain control amplifier for amplifying a signal reproduced by a magnetic head, a filter/equalizer circuit for removing a noise component from an output signal from the automatic gain control amplifier and wave-shaping the resultant signal, a rectifier for rectifying an output signal from the filter/equalizer circuit, a first low pass filter for low pass filtering an output signal from the rectifier to detect an average value thereof, and a charge pump and a capacitor for cooperating to control an amplification gain of the automatic gain control amplifier in response to an output signal from the first low pass filter.

Abstract: A delta sigma pulse width modulator control circuit uses a delta sigma modulator as a first stage to create a sequence of pulses representing an input control signal. A pulse width modulator accumulates the sequence of pulses and defines a pulse width modulated output signal from the accumulated pulses. The pulse width modulated signal is given a randomly generated offset to the time of pulse value transition and an adjacent pulse value matching technique is used to reduce harmonically related noise generation.

Abstract: A system for summoning a service industry worker using pulsed width modulation for remote signalling having a number of signalling switches, each connected to a transmitter. When a switch is activated, the corresponding transmitter transmits an RF carrier modulated by a lower frequency tone, turning the tone on and off in a pattern determined by a unique code assigned to the switch. A central receiver filters the signal from the transmitter and converts the tone pattern to a binary output to a computer. The computer instructs a display unit to turn on a light corresponding to the switch by sending its number in a serial bit stream of all lights that should be on. The bit stream is interpreted by circuits in the display unit using a clock signal. Upon the clock signal, the bit is sent to the appropriate register, which is used to turn on the correct light.

Abstract: A transmission apparatus for relaying different types of trunk signals, including a central processing unit including a reception counter processor which is inserted between a pair of exchanges and enables direct relay of exchange trunk signals (Sxt) and analog trunk signals (Sem) of a pulse ear and mouth (E&M) mode on a radio transmission line by counting the pulse width of the signals (Sem) and determining their type, a transmission counter processor which transmits the pulse E&M signals until the count of the pulse width inherent to the signals Sem corresponding to the signals Sxt is finished, and a logical operation unit which generates the corresponding signals Sxt based on the result of determination of the reception counter processor and drives the transmission counter processor based on the input signals Sxt, whereby it is possible to give an existing digital transmission apparatus handling E&M signals a function corresponding to a conventional higher rank exchange.

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 system for encoding control data onto a clock signal includes at least one clock cycle in the clock signal; a first transition in the at least one clock cycle, the first transition is from a first voltage level to a second voltage level, the first transition is in a first location in the at least one clock cycle; a second transition in the at least one clock cycle, the second transition is from the second voltage level to the first voltage level, the second transition has a variable location in the clock cycle; and an encoder circuit for positioning the second transition in the variable location in response to the control data.

Abstract: A user headset is provided that is operable to contain an audio device (50) and a receiver (52). The receiver (52) is operable to receive both audio information on multiple channels and also data. The data is received in the form of pulse width modulated sync signals. The sync signals are operable to provide a synchronization signal for 3-D liquid crystal lenses (60). The data is encoded within the sync signal through pulse width modulation. The width of the pulse defines various commands. These various commands define the channel over which the audio is to be transmitted. These channels can either be user-defined or they can be a function of the transmitter. The transmitter includes an audio generator (42) for generating audio signals on multiple channels and also a data generator (40). These are modulated onto a broad band optical signal and transmitted via an IR data link.

Abstract: Disclosed is a programmable sound generator for generating digital outputs of tone and noise signals used for producing computer sound effects. The programmable sound generator includes at least two channels generating digital output serving as either tone signal or noise signal. A mixer is used to process the outputs of the channels in a digital, time-sharing manner. A volume controller coupled to the mixer is used to control the volume of the sound in a digital pulse width modulation (PWM) manner. Also, the volume controller allows its output to become floating when the programmable sound generator is not in use so as to allow another sound generating means to share the same sound transducing means. In the programmable sound generator, the tone generation and the noise generation share the same hardware, which allows low-cost production of the programmable sound generator.

Abstract: A method and apparatus encodes and decodes machine readable signals in audio signals for producing humanly perceived audio transmissions. The encoding device includes circuitry for identifying portions of the audio signal having relatively low energy in a given band and relatively high energy in a band proximally below the given band. The machine readable signals are then inserted into the identified portions of the audio signal. According to another embodiment, the machine readable signals are encoded as a spread-spectrum signal which is added to the original audio signal. The spread-spectrum signal is scaled using a unique technique referred to as Common Mode Scaling.

Abstract: A communication system (5) provides an improved wired-OR connection for use in the bidirectional communication of information between two devices. A first device is a master host device (10) which initiates all communications while one or more slave devices (40) connected to a wired-OR common communication line either receive information from or send information to the master device. Depending on a direction of a data transfer operation, either the master or the host determines a bit time required to perform the data transfer. Furthermore, a device which terminates the bit time is the device which issues a speed up pulse for driving the common communication line to a logic one value. Such speed up pulses permit faster communication than is normally possible on a wired-OR communication line and makes high speed bidirectional communication over a single wired-OR line practical.

Abstract: A method and apparatus for transmitting binary data trains of 0 and 1 data bits, or combinations of these data bits over a communications network. The data bits are converted into pulses whose polarity changes from pulse to pulse, so as to enable an optimal exploitation of the transmission channel with a low error rate. The pulses generated by an apparatus of the present invention have a signal shape that produces a minimum inter-symbol interference. Processing and evaluation of the transmitted pulses are performed by a processor, so that a minimal error rate is attainable even under unfavorable transmission conditions.