A wireless communication unit for compensating for Ionospheric group delay in a satellite communication system. The wireless communication unit comprises: a receiver configured to receive a multi-carrier signal from a satellite; and a processor coupled to the receiver. The processor is configured to: process the multi-carrier signal to produce a plurality of digital representations of individual carriers of the multi-carrier signal; estimate, from the plurality of digital representations of individual carriers of the multi-carrier signal, a Total Electron Content, TEC, value associated with a communication path between the satellite and the wireless communication unit through Earth's Ionosphere; and apply compensation for Ionospheric group delay subjected to the multi-carrier signal based on the determined TEC value.

Cauls and methods of using cauls to produce composite articles are provided. The caul transitions from a rigid state to an elastomeric state and from an elastomeric state to a rigid state in response to a stimulus and has a reinforcement density of from 100 kg/m.sup.3 to 500 kg/m.sup.3. Methods of using cauls to produce composite articles involve positioning one or more fiber layers between a caul and a cure mold surface when the caul is in a rigid state. The fiber layers, caul, and cure mold surface may be covered with a sealed barrier and a pressure gradient may be applied. Before, after, or before and after performing the vacuum the fiber layers may be impregnated with resin. The fiber layers may be cured, which may provide a stimulus to transition the caul from a rigid to an elastomeric state, and the composite article is produced.

A lock-detection circuit detects whether a first clock signal is frequency locked to a second clock signal. A lock-detection scheme that continuously evaluates the lock condition between the clock signals and as programmable frequency-offset tolerances for reporting lock acquisition and loss. A quadrature clock generator produces two periodic signals from the first clock signal. The periodic signals are in quadrature, which is to say they are misaligned with one another by ninety degrees. These quadrature signals are sampled on edges of the second clock signal to produce a sequence of states that exhibit a Gray-code progression if first and second clock signals are locked. Errors in the Gray-code progression indicate whether edges of the first clock signal are early or late with respect to the second clock signal. The lock-detection circuit is adjustable to indicate loss of lock under in dependence upon the temporal spacing of errors.

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 method for receiving control information for a reference signal related to phase noise estimation by a user equipment (UE) comprises receiving control information indicating whether the reference signal related to the phase noise estimation is transmitted; when the control information indicates that the reference signal is transmitted, receiving the reference signal based on the control information; wherein when a size of a traffic resource block (RB) for the UE is greater than a predetermined value, the control information indicates the reference signal is transmitted.

Methods and systems are described for receiving, over a plurality of consecutive signaling intervals, a plurality of codewords, each codeword received as a plurality of symbols via wires of a multi-wire bus, the plurality of symbols received at a plurality of multi-input comparators (MICs), wherein each symbol is received by at least two MICs, generating, for each codeword, a corresponding linear combination of the received symbols, generating a plurality of composite skew measurement signals over the plurality of consecutive signaling intervals, each composite skew measurement signal based on samples of one or more linear combinations, and updating wire-specific skew values of the wires of the multi-wire bus, wherein one or more wire-specific skew values are updated according to composite skew measurement signals associated with linear combinations formed by at least two different MICs.

A master control device connected to a plurality of slave control devices via a network is configured to include an own local time counted by a counter unit, in a message and transmit the message to the slave control devices by the timing synchronization unit, calculate a difference between a reception time of a message transmitted from the slave control device, which has received the message, at a timing corrected in accordance with the local time and a pre-calculated message reception predicted time by a timing synchronization determination unit, calculate a correction amount for timing of the slave control devices using the difference by a timing synchronization correction unit, add the correction amount to the local time, include the local time in a message, and transmit the message to the slave control devices.

A method, device and system for synchronization message transmission are provided. The method may include that: a transmitting end selects at least one Ethernet Physical Layer Link (PHY) for synchronization message transmission from a Flexible Ethernet (FlexE) group (S201); after encapsulating the synchronization message according to a preset encapsulation strategy, the transmitting end inserts the synchronization message into a synchronization message channel in overhead of the selected Ethernet PHY (S202); and the transmitting end transmits the synchronization message through the selected Ethernet PHY (S203).

Provided is a reception apparatus capable of shortening a time period until the original data and clock can be recovered from a digital signal after temporary superimposition of noise on the digital signal stops. A reception apparatus 20 includes a receiver unit 21, a voltage-controlled oscillator 22, a sampler unit 23, a control voltage generation unit 24, an error detection unit 25, a training control unit 26, and an equalizer control unit 27. The receiver unit 21 includes an equalizer unit 21A. When the error detection unit 25 detects an error of a digital signal, the reception apparatus 20 causes a phase/frequency comparison by the control voltage generation unit 24 to be stopped.

System and method of frame alignment at a receiver with power optimization mechanisms. A framer is configured to perform a frame alignment process on a data stream and enter an inactive state after frame alignment is achieved. In the inactive state, the circuits used to perform the frame alignment process in the framer can be powered down or otherwise placed in a power reduction mode. Responsive to an indication that data processing at the receiver becomes out-of-frame again, the framer can wake up from the inactive state and restart the frame alignment process. An out-of-frame indication may be generated by error detection logic (e.g., forward error correction (FEC) decoder) when it detects an excessive number of uncorrectable errors.