The data recovery from sub-carriers gradients (DRSG) of a received OFDM signal affected by deterministic and random distortions introduced by a transmission link, contributes a method and a circuit for utilizing gradients characterizing shapes of OFDM sub-carriers comprised in such OFDM signal for recovering data symbols transmitted originally.

The data recovery from sub-carriers gradients (DRSG) of a received OFDM signal affected by deterministic and random distortions introduced by a transmission link, contributes a method and a circuit for utilizing gradients characterizing shapes of OFDM sub-carriers comprised in such OFDM signal for recovering data symbols transmitted originally.

A phase-locked loop (PLL) is implemented to have another (second) PLL in place of the controlled oscillator. When a known frequency change in the frequency of the output clock is desired, in addition to changing a configuration of the PLL (first PLL), the configuration of the second PLL is also changed to cause the frequency of the output clock to change quickly. In various embodiments, the configuration of the second PLL is changed by changing the divisor of the feedback divider of the second PLL, the divisor in a pre-scaler in the second PLL, the control voltage of a VCO used in the second PLL, and any other point of user control in the second PLL.

For example, an apparatus may include a digitally-controlled frequency multiplier, which may be controllable according to a digital control input, to generate an output frequency signal having an output frequency, for example, by multiplying an input frequency of an input frequency signal. For example, the digitally-controlled frequency multiplier may include a phase generator configured to generate a plurality of phase-shifted signal groups corresponding to a respective plurality of first phase-shifts applied to the input frequency signal, a plurality of digital clock multipliers controllable according to the digital control input to generate a respective plurality of frequency-multiplied signals based on the plurality of phase-shifted signal groups, and a combiner to generate the output frequency signal based on a combination of the plurality of frequency-multiplied signals.

A communication system comprising a master apparatus and a slave apparatus, wherein: the slave apparatus is configured, in an upstream period, to transmit a slave data signal to the master apparatus based on a slave clock signal; and the master apparatus is configured to: during reception of the slave data signal from the slave apparatus in the upstream period, extract timing information from the slave data signal and adjust a phase and/or frequency of a master clock signal or a definition thereof relative to a reference phase and/or frequency based on the extracted timing information to enable decoding of the received slave data signal based on the master clock signal or that definition; in a downstream period, transmit a master data signal to the slave apparatus based on the master clock signal according to the adjustment carried out during reception of the slave data signal in the upstream period; and adjust the phase and/or frequency of the master clock signal during transmission of the master data signal in the downstream period to reduce a change in the phase and/or frequency of the master clock signal effected according to the adjustment carried out during reception of the slave data signal in the upstream period.

Systems and methods for integrating injection-locked oscillators into transceiver arrays are disclosed. In one aspect, there is provided an injection-locked oscillator (ILO) distribution system including a master clock generator configured to generate a master clock signal. The ILO distribution system also includes an ILO distribution circuit including an ILO and configured to receive the master clock signal. The ILO is configured to generate a reference clock signal based on the master clock signal. The ILO distribution circuit is further configured to generate an output signal indicative of an operating frequency of the ILO. The ILO distribution system further includes an injection-locked detector (ILD) configured to receive the master clock signal and the output signal. The ILD is further configured to determine whether the ILO is in a locked state or in an unlocked state based on the master clock signal and the output signal.

Systems and methods described herein are related to clock signal generation for synchronous electronic circuitry. Power management in electronic devices circuitry may be implemented by scaling the frequency multiple functional modules implemented in the synchronous electronic circuitry. The present disclosure discussed clock generators that may provide frequency scaling of clock signals for functional modules within an electronic device. Moreover, certain clock signal generators may reduce mitigate generation of large currents during frequency scaling by employing circuitry that leads to incremental frequency changes. Circuitry that allows substantially glitchless or reduced-glitch transition between clock rate frequencies are also discussed.

In a particular implementation, a method to reduce noise/clock jitter and to generate a “stretched” output clock to optimize for jitter of the output clock is disclosed. The method includes: generating two or more clock phases upon detecting a transient voltage by a detector circuit, generating an output clock signal based on one of the two or more clock phases; and altering a phase speed of the output clock signal to correspond to a phase speed of an input clock signal.

An injection-locked oscillator includes an oscillator and an injection circuit. The oscillator includes a first oscillation node through which a first oscillation signal is output and a second oscillation node through which a second oscillation signal is output, the second oscillation signal having a phase opposite to that of the first oscillation signal. The injection circuit provides an injection current between the first oscillation node and the second oscillation node according to a reference signal. The injection circuit includes a charging element configured to be charged or discharged in response to a reference signal and to provide the injection current between the first oscillation node and the second oscillation node.

A method for generating a clock signal using a digital phase-locked loop includes updating a gain of a variable gain digital filter of the digital phase-locked loop using an estimate error of a current estimate of a phase and a frequency of an input clock signal and a measurement error of a measurement of the phase and the frequency of the input clock signal. The gain may include a proportional gain component and an integral gain component. The method may include calculating the current estimate of the phase and the frequency of the input clock signal based on a previous estimate of the phase and the frequency of the input clock signal, the measurement of the phase and the frequency of the input clock signal, and the gain of the variable gain digital filter. The gain may be updated every cycle of the input clock signal.