Time of day (ToD) registers provide respective virtual ToDs corresponding to the occurrence of edges of input clock signals being supplied to an integrated circuit. The integrated circuit generates a heartbeat clock signal having a frequency higher than a SYNC signal and time stamps the heartbeat clock signal to generate heartbeat time stamps. The heartbeat time stamps are used along with the time stamps of the input clock signals to determine the time of day corresponding to occurrences of edges of the input clock signals.

An inference unit (1033) predicts as a prediction parameter value, a future parameter value of a time synchronization parameter used for time synchronization calculation which is calculation for synchronizing times of two devices. When a measured parameter value which is a measured value corresponding to the prediction parameter value is generated with elapse of time, a cumulative distribution table generation unit (1034) calculates as a prediction error, a difference between the measured parameter value and the prediction value. A cumulative probability calculation unit (1036) calculates an abnormality degree indicating possibility that an abnormality is included in the measured parameter value, using the prediction error.

Systems and methods are disclosed for adjusting Radio Link Monitoring (RLM), Radio Link Failure (RLF) detection, RLF recovery, and/or connection establishment failure detection for wireless devices (16) in a cellular communications network (10) depending on mode of operation. In one embodiment, a node (14, 16) in the cellular communications network (10) determines whether a wireless device (16) (e.g., a Machine Type Communication (MTC) device) is to operate in a long range extension mode of operation or a normal mode of operation. The node (14, 16) then applies different values for at least one parameter depending on whether the wireless device (16) is to operate in the long range extension mode or the normal mode. The at least one parameter includes one or more RLM parameters, one or more RLF detection parameters, and/or one or more RLF recovery parameters. In doing do, signaling overhead and energy consumption within the wireless device (16) when operating in the long range extension mode is substantially reduced.

Disclosed embodiments relate to a system that changes transmitter and/or receiver settings to deal with reliability issues caused by a predetermined event, such as a change in a power state or a clock start event. One embodiment uses a first setting while operating a transmitter during a normal operating mode, and a second setting while operating the transmitter during a transient period following the predetermined event. A second embodiment uses similar first and second settings in a receiver, or in both a transmitter and a receiver employed on one side of a bidirectional link. The first and second settings can be associated with different swing voltages, edge rates, equalizations and/or impedances.

Methods and systems are provided for guard band detection and frequency offset detection. For each of a plurality of downconverted signals, frequency related information associated with one or more corresponding circuits used in obtaining the plurality of downconverted signals may be determined; and based on the determined frequency related information, one or both of a band stacking operation and a channel stacking operation may be performed. During the band stacking operation, frequency bands are not stacked on each other or stacked frequency bands do not overlap. During the channel stacking operation, channels are not stacked on each other or stacked channels do not overlap. The frequency related information may be determined based on predefined frequency related parameters associated with the corresponding circuits. Frequency corrections may be performed, on output signals corresponding to the band stacking operation and/or the channel stacking operation, based on the frequency related information.

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.

An error detection circuit, applied to a digital communication system with embedded clock, includes a time delay unit, a clock embedding encoding unit, a comparing unit and a packet error counting unit. The time delay unit delays a first digital encoded signal for a period of time. The clock embedding encoding unit generates a second digital encoded signal according to a first digital decoded signal, wherein the first digital decoded signal is generated by decoding the first digital encoded signal. The comparing unit is coupled to the time delay unit and the clock embedding encoding unit respectively and compares the first digital encoded signal with the second digital encoded signal to generate a compared result. The packet error counting unit is coupled to the comparing unit and counts a packet error rate according to the compared result and then provides a flag according to the packet error rate.

A method is provided for adjusting at least one transmit parameter of a digital transmitter of a communication system by estimating phase noise of a sequence of symbols received in a demodulator of a digital receiver of the communication system. The method includes: measuring a phase for the symbols of the sequence, deriving a total phase error for the sequence from the measured phases, determining a characteristic of the total phase error, deriving, based on a signal quality estimation of the received sequence of symbols, an indication of a contribution to the characteristic from at least one impairment different from phase noise, obtaining a phase noise estimation by subtracting the indication of the contribution from the characteristic of the total phase error, adjusting the at least one transmit parameter depending on the obtained phase noise estimation.

Systems and methods are disclosed for adjusting Radio Link Monitoring (RLM), Radio Link Failure (RLF) detection, RLF recovery, and/or connection establishment failure detection for wireless devices in a cellular communications network depending on mode of operation. In one embodiment, a node in the cellular communications network determines whether a wireless device (e.g., a Machine Type Communication (MTC) device) is to operate in a long range extension mode of operation or a normal mode of operation. The node then applies different values for at least one parameter depending on whether the wireless device is to operate in the long range extension mode or the normal mode. The at least one parameter includes one or more RLM parameters, one or more RLF detection parameters, and/or one or more RLF recovery parameters. In doing do, signaling overhead and energy consumption when operating in the long range extension mode is substantially reduced.

A receiving device includes: a resampler to convert a sampling rate of a reception signal, and output a first signal that is a signal having been subjected to sampling rate conversion; an equalizer to perform an adaptive equalization process using the first signal as an input, and output a second signal that is a signal having been subjected to the adaptive equalization process and having a sampling rate that is an integer fraction of an input signal; a correlation calculator to calculate a correlation function between the first signal and the second signal; and a rate controller to control a rate conversion ratio for sampling rate conversion in the resampler on a basis of the correlation function.