A spread-spectrum transmitter is disclosed. The transmitter includes a modulator configured to produce an intermediate frequency signal, a frequency shifter configured to shift the intermediate frequency factor by a first factor, and a local oscillator (LO) configured to generate a LO signal. The transmitter further includes a ramp signal generator configured to determine the value of the first factor and a second factor, is configured to transmit the value of the factor to the frequency shifter, is configured to transmit the value of the second factor to the LO, where the frequency of the intermediate frequency signal shifted by the first factor is shifted synchronously with the frequency of the LO signal shifted by the second factor. The transmitter includes a mixer configured to mix the shifted intermediate frequency with the shifted LO signal that has been shifted by the second factor, producing a spread leaked LO signal.

Systems and methods are disclosed for detecting node outages in a mesh network. A tracking node in the mesh network detects a set of signals originating from a tracked node in the mesh network. The set of signals includes beacons or communication messages transmitted by the tracked node. The tracking node determines that a threshold number of the beacon intervals have passed since receiving the most recent signal from the tracked node. The tracking node performs outage validation based on data received from another node in the mesh network and updates the status of the tracked node. Based on the updated status, the tracking node outputs a ping to the tracked node requesting a response to the ping. When the response to the ping is not received from the tracked node, the tracking node transmits an outage alarm message to a next topologically higher layer of the mesh network.

A satellite communication system is arranged for consecutively illuminating a plurality of contours on earth. The satellite communication system includes a modulator adjusting its transmission of data and dummy data to detected switching time instants, without causing too long delays or buffer overflows, or without impacting a return link synchronization. Traffic can be seamlessly switched to a redundant transmitter which is aligned with the beam hopping satellite to efficiently and reliably achieve synchronization.

A code acquisition module for a direct sequence spread spectrum (DSSS) receiver includes: a Sparse Discrete Fourier transform (SDFT) module configured to perform an SDFT on a finite number of non-uniformly distributed frequencies comprising a preamble of a received DSSS frame to calculate Fourier coefficients for the finite number of non-uniformly distributed frequencies; a multiplier configured to multiply the Fourier coefficients for the finite number of non-uniformly distributed frequencies of the received DSSS frame by complex conjugate Fourier coefficients for the finite number of non-uniformly distributed frequencies to generate a cross-correlation of the received DSSS frame and the complex conjugate Fourier coefficients; and a filter module configured to input the cross-correlation and output a delay estimation for the received DSSS frame.

The present application relates to wireless communications suitable for smart manufacturing and industrial automation. In particular, the application proposes a wireless communication device (UE) and a network device (BS), in particular suitable for cyclic communication. The BS is configured to provide a first information defining a hopping sequence to a UE, and to provide a second information to the UE defining when the hopping sequence should be repeated, in particular periodically repeated. The UE is accordingly configured to receive the first information from the BS, and to receive the second information from the BS. The hopping sequence specifies at least two spatial resources and/or at least two radio resources, which the UE is configured to use for transmissions to and/or from the BS.

A wireless communication device as an embodiment of the present invention is a wireless communication device for performing wireless communications with communication partners while switching channels to be used for each time slot, and includes a storage, an updater, a determinator, and a communicator. The storage stores pre-generated scheduling data indicating channels that can be used in each time slot. The updater determines whether or not each channel included in the scheduling data is usable, and registers the channel determined as unusable on a blacklist. The determinator determines the channel to be used in each time slot on the basis of the scheduling data and the blacklist. The communicator performs wireless communications with a communication partner by using the channel determined in each time slot.

Systems and methods are disclosed for detecting node outages in a mesh network. A tracking node in the mesh network detects a set of signals originating from a tracked node in the mesh network. The set of signals includes beacons or communication messages transmitted by the tracked node. The tracking node determines that a threshold number of the beacon intervals have passed since receiving the most recent signal from the tracked node. The tracking node performs outage validation based on data received from another node in the mesh network and updates the status of the tracked node. Based on the updated status, the tracking node outputs a ping to the tracked node requesting a response to the ping. When the response to the ping is not received from the tracked node, the tracking node transmits an outage alarm message to a next topologically higher layer of the mesh network.

Systems and methods are disclosed for detecting node outages in a mesh network. A tracking node in the mesh network detects a set of signals originating from a tracked node in the mesh network. The set of signals includes beacons and communication messages transmitted by the tracked node. The tracking node determines that a threshold number of the alive beacon intervals have passed since receiving a most recent signal from the tracked node. The tracking node then outputs a ping to the tracked node requesting a response to the ping. When the response to the ping is not received from the tracked node, the tracking node transmits an outage alarm message to a next topologically higher layer of the mesh network, the outage alarm message comprising an identification of the tracked node.

Systems and methods are disclosed for detecting node outages in a mesh network. A tracking node in the mesh network detects a set of signals originating from a tracked node in the mesh network. The set of signals includes beacons and communication messages transmitted by the tracked node. The tracking node determines that a threshold number of the alive beacon intervals have passed since receiving a most recent signal from the tracked node. The tracking node then outputs a ping to the tracked node requesting a response to the ping. When the response to the ping is not received from the tracked node, the tracking node transmits an outage alarm message to a next topologically higher layer of the mesh network, the outage alarm message comprising an identification of the tracked node.

Systems and methods are disclosed for detecting and reporting node power outages in a connected network. A node in the network detects that a power outage has occurred at the node and the node generates a last gasp packet using a packet format containing fewer data units than a regular packet format used by the network for communication. The node broadcasts the last gasp packet to its neighboring nodes. After receiving the last gasp packet, a neighboring node estimates the time of the power outage and converts the last gasp packet into an outage alarm message using the regular packet format. The neighboring node transmits the outage alarm message to a headend system to report the power outage at the node.