A method improves the transmission quality between a data collector and a plurality of metering units. A first communication module is assigned to the data collector and a second communication module is assigned in each case to a metering unit. The second communication module transmits data via radio signals to the first communication module. The first communication module has a first frequency reference device and the second communication module has a second frequency reference device. The radio signals transmitted are dependent on the second frequency reference device. The measurement of a parameter of the radio signal is performed by the first communication module. An estimation of an error of the second frequency reference device on the basis of the parameter measured values is determined. An adjustment of the frequency of the first frequency reference device is performed such that the error is reduced.

A method for receiving data performed by a non-Access Point (AP) station (STA) in a Wireless Local Area Network (WLAN) system is discussed. The method includes receiving, from an AP STA, a Multi User (MU) Physical Protocol Data Unit (PPDU); and transmitting, to the AP STA, a data frame based on the MU PPDU. Further, the MU PPDU includes a physical preamble and a data field sequentially.

A radio receiver device is arranged to receive a radio signal modulated with a data packet including an address portion. The radio receiver comprises: a synchronisation circuit portion arranged to produce synchronization information corresponding to the data packet; a demodulation circuit portion comprising a correlator, wherein said demodulation circuit portion is arranged to receive the radio signal and to produce an estimate of the address portion comprising a plurality of demodulated bits using said correlator and the synchronisation information; an address checking circuit portion arranged to receive the plurality of demodulated bits, to check said plurality of demodulated bits for a predetermined bit pattern, and to produce a match flag if it determines that the plurality of demodulated bits corresponds to the predetermined bit pattern. The radio receiver device is arranged such that, upon detecting an upcoming timeout event, the demodulation circuit portion sends a timeout warning signal to the address checking circuit portion using a handshaking channel therebetween; said address checking circuit portion being arranged such that, if it receives the timeout warning signal, it stops checking the plurality of demodulated bits for the predetermined bit pattern.

A radio receiver device is arranged to receive a radio signal modulated with a data packet including an address portion. The radio receiver comprises: a synchronisation circuit portion arranged to produce synchronization information corresponding to the data packet; a demodulation circuit portion comprising a correlator, wherein said demodulation circuit portion is arranged to receive the radio signal and to produce an estimate of the address portion comprising a plurality of demodulated bits using said correlator and the synchronisation information; an address checking circuit portion arranged to receive the plurality of demodulated bits, to check said plurality of demodulated bits for a predetermined bit pattern, and to produce a match flag if it determines that the plurality of demodulated bits corresponds to the predetermined bit pattern. The radio receiver device is arranged such that, upon detecting an upcoming timeout event, the demodulation circuit portion sends a timeout warning signal to the address checking circuit portion using a handshaking channel therebetween; said address checking circuit portion being arranged such that, if it receives the timeout warning signal, it stops checking the plurality of demodulated bits for the predetermined bit pattern.

A testing device and a method for testing a device under test are provided. The testing device comprises at least two signal generators, at least two numerically controlled oscillators, at least two white gaussian noise generators, at least two digital filters, each of which comprising a respective transfer function H.sub.i at least two adders, at least two digital-to-analog converters, and an analog processor.

The present disclosure relates to a method for demodulating a frequency modulated signal of a PMA standard wireless charging device, including: (1) reading coil signals, sampling the coil signals, and counting cycles; (2) extracting a frequency change according to a change in a cycle count; (3) determining data according to the frequency change and a frequency duration and outputting the data; and (4) splicing the outputted data. With the method, a demodulation part does not require a complex analog circuit, and the highest frequency desired at a digital circuit part is only 4 MHz. Moreover, at this frequency, there is only a simple addition operation, and the main operating frequency is below 236 KHz.

The present disclosure relates to a method for demodulating a frequency modulated signal of a PMA standard wireless charging device, including: (1) reading coil signals, sampling the coil signals, and counting cycles; (2) extracting a frequency change according to a change in a cycle count; (3) determining data according to the frequency change and a frequency duration and outputting the data; and (4) splicing the outputted data. With the method, a demodulation part does not require a complex analog circuit, and the highest frequency desired at a digital circuit part is only 4 MHz. Moreover, at this frequency, there is only a simple addition operation, and the main operating frequency is below 236 KHz.

A mixer is connected to a signal generator and an antenna and outputs a signal at an intermediate frequency. A PLL demodulator subjects the signal at the intermediate frequency from the mixer to PLL demodulation. An amplifier amplifies a signal from the PLL demodulator. A detector detects an amount of shift occurring in the PLL demodulator. A detector detects a gain of the amplifier. An FSK demodulator subjects a signal from the amplifier to FSK demodulation. An AFC unit detects a frequency offset in the signal from the amplifier and causes the signal generator to make a correction for the frequency offset detected.

A mixer is connected to a signal generator and an antenna and outputs a signal at an intermediate frequency. A PLL demodulator subjects the signal at the intermediate frequency from the mixer to PLL demodulation. An amplifier amplifies a signal from the PLL demodulator. A detector detects an amount of shift occurring in the PLL demodulator. A detector detects a gain of the amplifier. An FSK demodulator subjects a signal from the amplifier to FSK demodulation. An AFC unit detects a frequency offset in the signal from the amplifier and causes the signal generator to make a correction for the frequency offset detected.

Aspects of the subject disclosure may include, a system for receiving first electromagnetic waves that propagate along a physical transmission medium. The first electromagnetic waves can convey first signals in a first frequency range and second signals in a second frequency range, whereby a first spectral location of the first frequency range exceeds a second spectral location of the second frequency range. The system can further perform frequency converting of the first signals in the first frequency range to a first updated frequency range, frequency converting the second signals in the second frequency range to a second updated frequency range and generating second electromagnetic waves that propagate along the physical transmission medium and that convey the first signals in the first updated frequency range and the second signals in the second updated frequency range. Other embodiments are disclosed.