A detection system includes: a signal output unit configured to output, to a measurement target, a measurement signal that exhibits a predetermined temporal change; a signal measurement unit configured to measure a response signal, to the measurement signal, from the measurement target; a calculation unit configured to calculate an impulse response of the measurement target, based on a measurement result of the response signal measured by the signal measurement unit; and a detection unit configured to detect abnormality regarding the measurement target, based on the impulse response calculated by the calculation unit.

A detection system includes: a signal output unit configured to output, to a measurement target, a measurement signal that exhibits a predetermined temporal change; a signal measurement unit configured to measure a response signal, to the measurement signal, from the measurement target; a calculation unit configured to calculate an impulse response of the measurement target, based on a measurement result of the response signal measured by the signal measurement unit; and a detection unit configured to detect abnormality regarding the measurement target, based on the impulse response calculated by the calculation unit.

A synchronization detection device includes: a correction unit configured to correct sampled data of a waveform on which a dither signal is superimposed, for each period of a reference signal in accordance with a period of the dither signal; a multiplication unit configured to multiply the corrected sampled data by a weight coefficient that is different for each level of the reference signal and associated with a timing of the reference signal; and an averaging unit configured to derive, as a detection result, an average of a result of the multiplication of the corrected sampled data by the weight coefficient.

A synchronization detection device includes: a correction unit configured to correct sampled data of a waveform on which a dither signal is superimposed, for each period of a reference signal in accordance with a period of the dither signal; a multiplication unit configured to multiply the corrected sampled data by a weight coefficient that is different for each level of the reference signal and associated with a timing of the reference signal; and an averaging unit configured to derive, as a detection result, an average of a result of the multiplication of the corrected sampled data by the weight coefficient.

This application relates to the field of communications technologies and provides a quasi co-location indication method and an apparatus, so that a terminal learns of a quasi co-location relationship between a plurality of antenna ports of a first reference signal resource. The method includes: A terminal receives quasi-co-location indication information, where the quasi-co-location indication information is used to indicate M antenna port groups corresponding to a first reference signal resource, each of the M antenna port groups includes one or more CDM groups of the first reference signal resource, the CDM group includes a plurality of antenna ports, and any two antenna ports in a same antenna port group are in a quasi-co-location relationship. Then, the terminal determines a quasi-co-location relationship between a plurality of antenna ports of the first reference signal resource based on the quasi-co-location indication information.

A synchronization method includes obtaining a first timestamp difference of a packet on a target link. The first timestamp difference is a difference between a sending timestamp and a receiving timestamp of the packet at a first moment. The synchronization method further includes performing packet selection based on the first timestamp difference to obtain a second timestamp difference; obtaining a delay prediction value of the target link at the first moment, compensating for the second timestamp difference based on the delay prediction value to obtain a compensated timestamp difference; and performing time and/or clock synchronization based on the compensated timestamp difference. The second timestamp difference is compensated for based on the delay prediction value, that is, PDV noise introduced to the target link is compensated for. In this way, the PDV noise is reduced.

A synchronization method includes obtaining a first timestamp difference of a packet on a target link. The first timestamp difference is a difference between a sending timestamp and a receiving timestamp of the packet at a first moment. The synchronization method further includes performing packet selection based on the first timestamp difference to obtain a second timestamp difference; obtaining a delay prediction value of the target link at the first moment, compensating for the second timestamp difference based on the delay prediction value to obtain a compensated timestamp difference; and performing time and/or clock synchronization based on the compensated timestamp difference. The second timestamp difference is compensated for based on the delay prediction value, that is, PDV noise introduced to the target link is compensated for. In this way, the PDV noise is reduced.

Systems for determining a phase of a device coupled to an electrical distribution system. The system includes a number of gateway devices configured to transmit a synchronization signal. The gateway device receives a node response message from a first node device that includes a duration value indicating a time between a receipt of the transmitted synchronization signal and a detected zero crossing. The gateway device compares the duration value against duration values received from node devices with a known phase connection and determines a phase of the first node device based on the comparison.

Systems for determining a phase of a device coupled to an electrical distribution system. The system includes a number of gateway devices configured to transmit a synchronization signal. The gateway device receives a node response message from a first node device that includes a duration value indicating a time between a receipt of the transmitted synchronization signal and a detected zero crossing. The gateway device compares the duration value against duration values received from node devices with a known phase connection and determines a phase of the first node device based on the comparison.

A phase calibration method includes sweeping phase codes applicable to a serial clock signal, identifying a first, a second, a third, and a fourth phase code, wherein the first phase code causes zero plus a first threshold number of bits extracted from the serial data signal to be a particular value, wherein the second phase code causes all minus a second threshold number of bits extracted from the serial data signal to be the particular value, wherein the third phase code causes all minus a third threshold number of bits extracted from the serial data signal to be the particular value, wherein the fourth phase code causes zero plus a fourth threshold number of bits extracted from the serial data signal to be the particular value, determining an average phase code based on the identified phase codes.