摘要:
The invention relates to a radio receiver for the reception of a data burst which is transmitted by a transmitter, in which case the data burst includes a first section which has been modulated using a first modulation method at the transmitter end, and a second section which is transmitted after the first section and has been modulated using a second modulation method at the transmitter end. The radio receiver has a first reception path for processing of the first section and a second reception path for processing of the second section.
摘要:
The invention specifies a circuit arrangement with a phase locked loop (1), which can be used as a mobile radio transmitter, in particular. The reference frequency for the PLL (1), which is provided by means of the source (3), is multiplied by a multiplier (10) and is down-converted to an intermediate-frequency level in a down-conversion mixer (9) using the output signal from the PLL, and is evaluated such that a modulator (13) connected to the input of the oscillator (6) can be trimmed. The inventive principle is used to advantage in two-point modulators and allows inexpensive, integratable mobile radio transmitters with good noise characteristics.
摘要:
In a method for qualification of the transmission quality of a frequency channel in a wire-free communication system that has two or more frequency channels, units in the system communicate via the frequency channels. Data is transmitted in time slots in a time pattern using a time slot method. The influence of possible interference sources is determined in a measurement time slot in which no data is received, in that the field strength is measured at the frequencies of two or more frequency channels, and the field strength information is used for qualification decisions relating to the frequency channels.
摘要:
An electronic device is equipped with an oscillator interface to be coupled to an oscillator crystal of an oscillator element. The electronic device includes an oscillator circuit which is coupled to the oscillator interface and generates an oscillator signal. The electronic device is further provided with a temperature measurement interface to be coupled to a temperature sensor of the oscillator element so as to receive the temperature signal. For accomplishing temperature compensation, the electronic device is provided with a measurement controller coupled to the measurement interface and configured to measure a first value of the temperature signal at a first point of time and a second value of the temperature signal at a second point of time. A frequency drift estimator is provided so as to estimate a frequency drift of the oscillator signal on the basis of the first value of the temperature signal and a second value of the temperature signal. By means of a compensation logic, a frequency compensation signal for the oscillator circuit is generated on the basis of the estimated frequency drift.
摘要:
An optoelectronic sensor (10) for monitoring a working area (42) is provided, the working area (42) being located within a detection area (20) of the sensor (10) and in a first distance from the sensor (10), wherein the sensor (10) comprises an illumination unit (22) with a light source (24) for at least partially illuminating the working area (42), and an object detection unit (30) for detecting forbidden objects in the working area (42), wherein an illumination control (28) of the illumination unit (22) is configured to, during a startup period, initially activate the illumination unit (28) with a lower power such that a provisional working area (40, 40a-c) in a second distance from the sensor (10) less than the first distance is illuminated at most with a predetermined maximum light output; test whether there is a forbidden object intrusion into the provisional working area (40, 40a-c); and if no forbidden object intrusion is detected, activate the illumination unit (28) with a higher power such that the working area (42) is illuminated at most with the predetermined maximum light output. The illumination control (28) comprises a short range object detection unit (39) configured to test the provisional working area (40, 40a-c) in a different way than the object detection unit (30) tests the working area (42).
摘要:
An optoelectronic sensor includes at least one light transmitter for the transmission of light signals into a monitored zone, at least one light receiver for the reception of light signals transmitted from the light transmitter and a control device for the generation and/or influencing of the light signals and for the generation of an object detection signal in the case of the presence of an object in the monitored region in dependence on the output signals of the light receiver. In this connection, the light signals transmitted into the monitored zone by the light transmitter are each generated by an output signal modulated in accordance with the spread spectrum method using a random pseudo-noise code.
摘要:
Representative implementations of direct FM/PM modulation and systems are disclosed describing frequency modulation or phase modulation of information onto a carrier signal using a divider that is remote from the carrier signal generation path.
摘要:
Communication devices and methods are disclosed, wherein a test signal is generated at a first frequency and a higher harmonic of said test signal is received and processed at a second frequency higher than said first frequency.
摘要:
A lighting unit (100) having a divergent coherent light source (104, 106) is provided for the generation of an at least locally irregular pattern (20) in a monitored zone (12). In this respect, the lighting unit (100) has an optical phase element (108, 110) in the beam path of the light source (104, 106), said optical phase element having unevenness made to generate local phase differences between light portions incident at the phase element at adjacent positions and thus to generate the irregular pattern (20) by interference.