The present invention relates to a method, a device and a system for signal synchronization of a satellite communication system. The method comprises: obtaining the first transmission delay of the feed link of a satellite communication system and the second transmission delay of the user link of the satellite communication system, obtaining a time sequence regulation value according to the difference of the first transmission delay and the second transmission delay, transmitting the time sequence regulation value to a communication terminal, and regulating a signal emission time sequence according to the time sequence regulation value through the communication terminal. A LTE downlink transmission channel is ground gateway station-satellite-communication terminal, the TtT uplink transmission channel of the communication terminal is communication terminal-satellite, and for a receiver of the satellite after regulation, the subframe boundaries of the TtT uplink transmission and the LTE downlink transmission are aligned to satisfy the signal synchronization requirement of the TtT and LTE transmission modes with no need for improvement of a TtT physical layer so as to reduce the complexity of the satellite communication system design while realizing signal synchronization.

Method, device and system for signal synchronization of satellite communication system

The embodiment of the invention provides a UWB based signal synchronization method and an indoor positioning system. The method is applied to the indoor positioning system and comprises the steps of forwarding an outdoor base station positioning signal to a first-level positioning node of each link in an indoor positioning network corresponding to the indoor positioning system by a repeater; performing preset processing on a positioning signal by the first-level positioning node of each link to obtain a corresponding synchronous positioning signal; sending the corresponding synchronous positioning signal and signal flight time to the next-level positioning node of the link by each level of the positioning node from the first-level positioning node to the reciprocal second-level positioningnode of each link; and performing clock correction on the received synchronous positioning signal based on the received signal flight time by the next-level positioning node so as to obtain a corresponding synchronous positioning signal. The UWB based signal synchronization method realizes synchronization of indoor positioning nodes and positioning signals via a wireless communication mode, simplifies the installation and maintenance process of the indoor positioning system and is convenient for adjusting the position of each positioning node.

UWB based signal synchronization method and indoor positioning system

The present invention provides a sensor management device, a sensor information synchronization method, a control program, and a recording medium. The sensor management device has a technology that enables a plurality of sensor information to be synchronized for a technology of a sensor management device communicating with a plurality of wireless sensors in a time division manner. The sensor management device includes a transmission unit (7) that transmits acquisition start instructions for starting acquisitions of sensor information to a plurality of wireless sensors respectively at different timings; and an extraction unit (8) that extracts a plurality of common period sensor information that the plurality of wireless sensors have acquired in the common period from the plurality of sensor information with reference to deviation of times at which the transmission unit has transmitted the acquisition start instructions to the plurality of wireless sensors.

Sensor management device, sensor information synchronization method, control program, and recording medium

Provided is a technology that enables a plurality of sensor information to be synchronized for a technology of a sensor management device communicating with a plurality of wireless sensors in a time division manner. A sensor management device includes a transmission unit that transmits acquisition start instructions for starting acquisitions of sensor information to a plurality of wireless sensors respectively at different timings; and an extraction unit that extracts a plurality of common period sensor information that the plurality of wireless sensors have acquired in the common period from the plurality of sensor information with reference to deviation of times at which the transmission unit has transmitted the acquisition start instructions to the plurality of wireless sensors.

Sensor management device, sensor information synchronization method, and non-transitory computer readable recording medium

The present invention relates to the technical field of wireless sensor networks, and relates to a frequency offset estimation method for average consistency clock synchronization. According to the method, solving of maximum likelihood estimation is converted into a linear optimization problem in combination with distributed one-way broadcast characteristics, and a relative frequency offset estimation value is obtained by adopting an iterative method. By applying the estimation value to inter-node logic clock parameter compensation, the effect of keeping logic clocks of network nodes consistent can be achieved. According to the present invention, the distribution characteristics of the communication time delay are fully considered, accurate relative frequency offset estimation can be implemented, so that the synchronization precision of average consistency clock synchronization is effectively improved, the maximum likelihood estimation solution is performed by adopting the iterative method, an estimation algorithm is simplified, and storage overhead is reduced.

Frequency offset estimation method for average consistency clock synchronization

The invention relates to a clock synchronizing frequency deviation estimation method applicable to a multi-hop wireless sensor network, and belongs to the technical field of the wireless sensor network. In the clock synchronizing frequency deviation estimation method, two methods, including, a forwarding method and an unvarnished transmission method, are provided based on demands of a node for synchronization precision: A, in the forwarding method, a node in an intermediate layer initiates synchronous interaction with a node in the next layer at the same time interval after every correction time; and B, in the unvarnished transmission method, the processing time of the node in the intermediate layer is regarded as an additionally introduced fixed time delay and random time delay, and the node directly establishes a synchronization relationship with a root node. According to the estimation method provided by the invention, the node can correct the local clock in each synchronous information interaction process, the synchronization precision error of the node is enabled to be always kept at a relatively low level, and the problem of synchronization precision uncontrollability in a synchronization parameter estimation process is accordingly overcome.

Wang Heng

Papers

Clock synchronization frequency deviation estimation method applicable to multi-hop wireless sensor network