Abstract:
A transmitter includes estimation circuitry and correction circuitry. The estimation circuitry is configured to estimate, based at least on a phase error between a local oscillator and a reference frequency, values for parameters that describe a frequency deviation experienced by a phase locked loop (PLL) during transmission of the data sample, wherein the PLL includes a local oscillator. The correction circuitry is configured to generate a correction term based at least on the estimated parameters; adjust the data sample with the correction term to generate a compensated data sample; and provide the compensated data sample for modulation of a carrier wave generated by the local oscillator.
Abstract:
A transmitter includes estimation circuitry and correction circuitry. The estimation circuitry is configured to estimate, based at least on a phase error between a local oscillator and a reference frequency, values for parameters that describe a frequency deviation experienced by a phase locked loop (PLL) during transmission of the data sample, wherein the PLL includes a local oscillator. The correction circuitry is configured to generate a correction term based at least on the estimated parameters; adjust the data sample with the correction term to generate a compensated data sample; and provide the compensated data sample for modulation of a carrier wave generated by the local oscillator.
Abstract:
A transmitter includes an amplitude modulation path, and a frequency modulation path including a phase locked loop (PLL) having a controllable oscillator and a phase detector. The transmitter further includes an amplitude to frequency distortion compensation unit configured to generate a compensation signal based on amplitude data from the amplitude modulation path, error data based on an output of the phase detector, and data reflecting a transfer function from the controllable oscillator to the output of the phase detector, and is further configured to provide the compensation signal to a node in a feedforward path of the PLL.
Abstract:
A synthesizer circuit to generate a local oscillator carrier signal for a baseband signal includes a controlled oscillator comprising a phase lock loop and an oscillator configured to generate an oscillating signal. A pulling compensation circuit is configured to generate a correction signal for a present output of the phase locked loop using information on an error of the oscillating signal, information on a present sample of a baseband signal and a preceding correction signal for a preceding output of the phase locked loop.
Abstract:
A synthesizer circuit to generate a local oscillator carrier signal for a baseband signal includes a controlled oscillator comprising a phase lock loop and an oscillator configured to generate an oscillating signal. A pulling compensation circuit is configured to generate a correction signal for a present output of the phase locked loop using information on an error of the oscillating signal, information on a present sample of a baseband signal and a preceding correction signal for a preceding output of the phase locked loop.
Abstract:
An apparatus for reducing an amplitude imbalance and a phase imbalance between an in-phase signal and a quadrature signal is provided. The in-phase signal and the quadrature signal are based on a radio frequency receive signal. The apparatus includes an imbalance estimation module configured to generate a first correction signal related to a first phase shift, and to generate a second correction signal related to a second phase shift. Further, the apparatus includes a first digital-to-time converter configured to receive the first correction signal and a local oscillator signal. The first digital-to-time converter is further configured to supply a first replica of the local oscillator signal for a first mixer generating the in-phase signal, wherein the first replica of the local oscillator signal has the first phase shift with respect to the local oscillator signal. The apparatus further includes a second digital-to-time converter configured to receive the second correction signal and the local oscillator signal. The second digital-to-time converter is further configured to supply a second replica of the local oscillator signal for a second mixer generating the quadrature signal, wherein the second replica of the local oscillator signal has the second phase shift with respect to the local oscillator signal.
Abstract:
A hybrid polar I-Q transmitter comprises an I-Q quantization circuit configured to receive an in-phase signal and a quadrature signal forming a first I-Q data pair, and generate a quantized in-phase signal and a quantized quadrature signal forming a second I-Q data pair, respectively, based on a resolution information of a digital-to-analog converter (DAC). Each of the first and second I-Q data pairs corresponds to a point in an I-Q constellation diagram comprising an I axis and a Q axis that are orthogonal to one another. The transmitter further comprises a quantization reduction circuit configured to determine a first rotation angle and a second rotation angle of the I-axis and Q-axis, respectively, based on the first I-Q data pair and the second I-Q data pair, and use the determined first rotation angle and the second rotation angle for generating an RF output signal.
Abstract:
A hybrid polar I-Q transmitter includes an I-Q derivation circuit configured to receive a first and second I-Q data components comprising a first I-Q data pair, and generate a first and second I-Q derived data components comprising a second I-Q data pair, respectively, based thereon, by utilizing a resolution information of a digital-to-analog converter (DAC) and a design criteria. The I-Q derivation circuit is further configured to determine a residual angle corresponding to a phase angle difference between the first I-Q data pair and the second I-Q data pair. The hybrid polar I-Q transmitter further comprises a modulation circuit configured to compensate the determined residual angle corresponding to the phase angle difference between the first I-Q data pair and the second I-Q data pair.
Abstract:
An apparatus for reducing an amplitude imbalance and a phase imbalance between an in-phase signal and a quadrature signal is provided. The in-phase signal and the quadrature signal are based on a radio frequency receive signal. The apparatus includes an imbalance estimation module configured to generate a first correction signal related to a first phase shift, and to generate a second correction signal related to a second phase shift. Further, the apparatus includes a first digital-to-time converter configured to receive the first correction signal and a local oscillator signal. The first digital-to-time converter is further configured to supply a first replica of the local oscillator signal for a first mixer generating the in-phase signal, wherein the first replica of the local oscillator signal has the first phase shift with respect to the local oscillator signal. The apparatus further includes a second digital-to-time converter configured to receive the second correction signal and the local oscillator signal. The second digital-to-time converter is further configured to supply a second replica of the local oscillator signal for a second mixer generating the quadrature signal, wherein the second replica of the local oscillator signal has the second phase shift with respect to the local oscillator signal.
Abstract:
A transmitter comprising a phase computation circuit configured to receive a complex baseband signal comprising an in-phase signal and a quadrature signal forming an I-Q data pair, and determine a first rotation angle and a second rotation angle based on the I-Q data pair. The transmitter further comprises a modulation circuit coupled to the phase computation circuit configured to determine a three-level modulated waveform having a lower negative level, a zero level and a higher positive level, based on the first rotation angle and the second rotation angle; and generate the three-level modulated waveform based on the determination.