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 disclosure provides a delay estimation device and a delay estimation method. The delay estimation device includes a pulse generator, a digitally controlled delay line (DCDL), a time-to-digital converter (TDC), and a control circuit. The pulse generator receives a reference clock signal, outputs a first clock signal in response to a first rising edge of the reference clock signal, and outputs a second clock signal in response to a second rising edge of the reference clock signal. The DCDL receives the first clock signal from the pulse generator and converts the first clock signal into phase signals based on a combination of delay line codes. The TDC samples the phase signals to generate a timing code based on the second clock signal. The control circuit estimates a specific delay between the first clock signal and the second clock signal based on the timing code.

A semiconductor device has a current controlled oscillation circuit configured to generate an oscillation clock in response to a current supplied, a first circuit configured to output a first signal when a phase of the oscillation clock is later than a phase of reception data, and to output a second signal when a phase of the oscillation clock is earlier than a phase of the reception data, and a current control circuit configured to control a current to be supplied to the current controlled oscillation circuit such that the number of times of output of the first signal from the first circuit matches the number of times of output of the second signal from the first circuit.

A data transmitting and receiving system includes a first device including an encoder configured to encode row data to generate precoding data and a transmitter configured to transmit the precoding data through a transmission channel and a second device including an integrator configured to perform an integral on the precoding data, an integral sampler including a plurality of samplers configured to output sampling data based on an offset value and an output value of the integrator, a decoder configured to decode outputs of some of the samplers to generate decoded data, and a phase detector configured to detect a phase difference between the precoding data and a clock based on the decoded data and an output of another one of the samplers.

A data transmitting and receiving system includes a first device including an encoder configured to encode row data to generate precoding data and a transmitter configured to transmit the precoding data through a transmission channel and a second device including an integrator configured to perform an integral on the precoding data, an integral sampler including a plurality of samplers configured to output sampling data based on an offset value and an output value of the integrator, a decoder configured to decode outputs of some of the samplers to generate decoded data, and a phase detector configured to detect a phase difference between the precoding data and a clock based on the decoded data and an output of another one of the samplers.

A clock data recovery circuit includes a phase detector, a first signal processing path, a second signal processing path, an oscillator circuit and a phase control circuit. The phase detector samples input data signal according to first clock signals to generate an up control signal and a down control signal. The first signal processing path includes at least one first signal processing device generating a phase control signal according to the up control signal and the down control signal. The second signal processing path includes at least one second signal processing device generating a frequency control signal according to the up control signal and the down control signal. The oscillator circuit generates second clock signals according to the frequency control signal. The phase control circuit controls phases of the second clock signals according to the phase control signal to generate the first clock signals.

A sub-sampling phase locked loop includes a slope generating and sampling circuit, first and second transconductance circuits, a constant transconductance bias circuit, a loop filter and a voltage controlled oscillator. The slope generating and sampling circuit generates a sampling voltage based on a reference clock signal and an output clock signal. The first and second transconductance circuits generate first and second output control voltages based on the sampling voltage, a reference voltage and a control current. The constant transconductance bias circuit includes a switched capacitor resistor. The constant transconductance bias circuit is configured to generate the control current. The loop filter is connected to output terminals of the first and second transconductance circuits. The voltage controlled oscillator generates the output clock signal based on the first and second output control voltages.

A sub-sampling phase locked loop includes a slope generating and sampling circuit, first and second transconductance circuits, a constant transconductance bias circuit, a loop filter and a voltage controlled oscillator. The slope generating and sampling circuit generates a sampling voltage based on a reference clock signal and an output clock signal. The first and second transconductance circuits generate first and second output control voltages based on the sampling voltage, a reference voltage and a control current. The constant transconductance bias circuit includes a switched capacitor resistor. The constant transconductance bias circuit is configured to generate the control current. The loop filter is connected to output terminals of the first and second transconductance circuits. The voltage controlled oscillator generates the output clock signal based on the first and second output control voltages.

A phase-locked loop circuit includes a voltage controlled oscillator (VCO) that generates a VCO clock in response to a voltage control signal, a divider that divides the VCO clock to output a division clock, a phase-frequency error detector that receives a reference clock and outputs a first error compensation signal, a sampler that receives the reference clock and oversamples the reference clock at a rising edge or a falling edge to output a sampling clock, a window phase error detector that receives the reference clock and outputs a second error compensation signal, a residue phase error detector that outputs a third error compensation signal, an adder that accumulates the first error compensation signal, the second error compensation signal, and the third error compensation signal to output a final error compensation signal, and a loop filter that converts and output the final error compensation signal into the voltage control signal.

A phase-locked loop circuit includes a voltage controlled oscillator (VCO) that generates a VCO clock in response to a voltage control signal, a divider that divides the VCO clock to output a division clock, a phase-frequency error detector that receives a reference clock and outputs a first error compensation signal, a sampler that receives the reference clock and oversamples the reference clock at a rising edge or a falling edge to output a sampling clock, a window phase error detector that receives the reference clock and outputs a second error compensation signal, a residue phase error detector that outputs a third error compensation signal, an adder that accumulates the first error compensation signal, the second error compensation signal, and the third error compensation signal to output a final error compensation signal, and a loop filter that converts and output the final error compensation signal into the voltage control signal.