Telefonaktiebolaget Lm Ericsson (publ)

Tony Påhlsson

Henrik Sjöland

Staffan Ek

Mohammed Abdulaziz

Lars Sundström

Sven Erik Mattisson

Anders Carlsson

Henrik Pia Sjöland

An apparatus is disclosed for provision of an indication of an angular difference between first and second input signals. The apparatus comprises a phase frequency detector (PFD) configured to receive the first and second input signals and to provide first and second outputs based on the first and second input signals. A difference in pulse length between signals provided at the first and second outputs is indicative of the phase difference between the first and second input signals. The apparatus also comprises first and second time-to-digital converters (TDCs) each configured to receive one of the signals provided by the PFD and to provide a corresponding digital pulse length representation. Each of the TDCs is a pulse length modifying TDC, wherein pulse length modification may comprise pulse length shrinking or pulse length extension. The apparatus also comprises a comparator configured to provide the indication of the phase difference based on the digital pulse length representations provided by the first and second TDCs. Corresponding digital phase-locked loop (DPLL) and communication device are also disclosed.

Apparatus for digital representation of angular difference

A calibration unit and method therein for calibrating a TDC comprised in a digital PLL are disclosed. The TDC receives a signal from a free-running DCO and a reference signal, and measures the time difference between the DCO and reference signals. The calibration unit receives and processes data samples output from the TDC and generates a calibration lookup table in which each TDC output value has a calibration value. The calibration lookup table may be used for post-distortion. For each TDC output level the corresponding calibration value from the lookup table may be added to the output of the TDC for correction.

Time to digital converter calibration

A frequency determination device for determining a frequency relationship between a reference signal and a clock signal. Each constituent TDC is configured to provide a digitally represented constituent output signal in response to receiving a constituent reference signal and a constituent clock signal, and the frequency determination device is configured to successively provide respectively delayed versions of the constituent clock signal of a first constituent TDC as respective constituent clock signals to the other constituent TDC:s. The reference signal provider is configured to provide the respective constituent reference. The switching circuitry is configured to provide the reference signal as the constituent clock signal to the first constituent TDC. The determination circuitry is configured to determine a number of consecutively same-valued symbols in a concatenation of the digitally represented constituent output signals of the constituent TDC:s, and to determine the frequency relationship.

Devices and method for frequency determination

A Time to Digital Converter (TDC) arrangement includes a first delay circuit configured to receive a signal with N phases; a set of phase detectors configured to compare each phase of the signal with a reference signal; a logic circuit configured to receive output signals from the set of phase detectors and detect which phase signal that is the closest signal leading or lagging the reference signal; a first multiplexer configured to receive outputs from the first delay circuit and the logic circuit; a second delay circuit configured to delay the reference signal; a TDC configured to receive output signals from the first multiplexer and the second delay circuit; an adder configured to sum outputs from the logic circuit and the TDC and generate an output signal of the TDC arrangement.

Time to digital converter arrangement with increased detection range

A time-to-digital converter (TDC) circuitry for converting a phase difference between an input reference signal and an input clock signal to a digitally represented output signal. The TDC circuitry comprises multiple constituent TDCs, a reference signal provider, and a digital signal combiner. Each TDC is configured to convert a phase difference between a constituent reference signal and a constituent clock signal to a digitally represented constituent output signal. The reference signal provider is configured to provide the respective constituent reference signals to each of the TDCs. In at least a parallel operation mode of the TDC circuitry, each respective constituent reference signal comprises a respectively delayed version of the input reference signal with different respective delays for at least two of the respective constituent reference signals. The digital signal combiner is configured to provide the digitally represented output signal based on the digitally represented constituent output signals of the TDCs.

Time-to-digital converter circuitry

A time-to-digital converter (TDC) circuitry is disclosed for converting a phase difference between an input reference signal () and an input clock signal () to a digitally represented output signal (). The TDC circuitry comprises a plurality of constituent TDC:s (), a reference signal provider (), and a digital signal combiner (). Each constituent TDC is configured to convert a phase difference between a constituent reference signal () and a constituent clock signal () to a digitally represented constituent output signal (). The reference signal provider () is configured to provide the respective constituent reference signals () to each of the constituent TDC:s (). In at least a parallel operation mode of the TDC circuitry, each respective constituent reference signal comprises a respectively delayed version of the input reference signal () with different respective delays for at least two of the respective constituent reference signals. The digital signal combiner () is configured to provide the digitally represented output signal () based on the digitally represented constituent output signals () of the constituent TDC:s. A corresponding method and devices comprising the TDC circuitry are also disclosed.

A phase locked loop arrangement () beamforming comprises two or more phase locked loops. The loops include a phase comparator () and an adjustable charge pump arrangement () having a loop filter () and charge pump current source () with an adjustment input (&#x3d5;) connected to the loop filter () to inject an adjustable charge pump current into the loop filter. A constant current source () is configured to inject a first predetermined charge current into the loop filter (). The adjustable charge pump arrangements () are connected to the respective phase comparators () to provide a voltage control signal (vctrl) to an oscillator () of the respective phase adjustable phase locked loop () in response to the respective control signal (up, down) and to generate a phase deviation between the first and one of the at least one second oscillator signals (f, f) based on an adjustment signal applied to the adjustment input (&#x3d5;).

Phase locked loop arrangement, transmitter and receiver and method for adjusting the phase between oscillator signals

A fractional-N frequency synthesizer circuit is disclosed. It comprises a frequency divider circuit configured to receive a first oscillation signal having a first frequency, to receive a control word indicating a divisor, and to frequency divide the first oscillation signal with the divisor to generate a second oscillation signal having a second frequency, lower than the first frequency. It also comprises a modulator circuit configured to generate a sequence of control words to the frequency divider circuit. The modulator circuit comprises a set of memory elements configured to store an internal state of the modulator circuit in response to a first control signal and to restore the internal state of the modulator circuit in response to a second control signal, thereby enabling a time shift of the sequence of control words. A communication circuit, a communication apparatus, and a method are also disclosed.

Frequency synthesizer

A system for phase control of a Phased Locked Loop, PLL, is disclosed. The system includes the PLL. The PLL includes an oscillator configured to generate an output signal; a frequency divider configured to generate a feedback signal by dividing the output signal from the oscillator; a first phase detector arrangement configured to output a first control signal to control the oscillator in response to a detection of a phase deviation between a reference signal and the feedback signal. A second phase detector is configured to receive the feedback signal from the frequency divider and the reference signal, and generate an output signal. A phase calibration circuit is configured to receive the output signal from the second phase detector and generate a second control signal to adjust a phase of the output signal of the oscillator.

System for phase calibration of phase locked loop

A phase locked loop, for a particularly in a beamforming system comprises a loop filter () to provide a control signal (FC) to a controllable oscillator (); a frequency divider () configured to provide a first feedback signal (FB) and a second feedback signal (FBD) in response to an oscillator signal (FO), wherein the second feedback signal (FBD) is delayed with respect to the first feedback signal (FB). An interpolator is configured to receive the first and the second feedback signal (FB) and to provide an interpolated signal thereof between the first and second feedback signal and in response to a phase control word. A comparator path is configured to receive the interpolated signal and to provide a respective signal to the loop filter () in response to a phase deviation between a common reference signal (FR) and the interpolated signal.

Phase locked loop, phase locked loop arrangement, transmitter and receiver and method for providing an oscillator signal

A phase locked loop, particularly for or in a beamforming system comprises a loop filter () to provide a control signal (FC) to a controllable oscillator (); a frequency divider () configured to provide a first feedback signal (FB) and a second feedback signal (FBD) in response to an oscillator signal (FO), the second feedback signal (FBD) delayed with respect to the first feedback signal (FB); a first comparator path () configured to receive the first feedback signal (FB) and a second comparator path () configured to receive the second feedback signal (FBD), each of the first and second comparator path () configured to provide a respective current signal (CS, CS) to the loop filter () in response to a respective adjustment signal (FA, FA) and a phase deviation between a common reference signal (FR) and the respective feedback signal (FB, FBD).

A phase locked loop, for a particularly in a beamforming system comprises a digital loop filter to provide a digital control word to a controllable oscillator; a frequency divider configured to provide a first feedback signal and a second feedback signal in response to an oscillator signal, the second feedback signal delayed with respect to the first feedback signal; a first comparator path configured to receive the first feedback signal and a second comparator path configured to receive the second feedback signal, each of the first and second comparator path configured to provide a respective phase delay signal to the digital loop filter in response to a respective adjustment signal and a phase deviation between a common reference signal and the respective feedback signal.

Exemplary embodiments include an electronic frequency-divider circuit comprising a multi-phase generator circuit configured to: receive an oscillating input signal having a frequency f; determine an integer divide ratio Q based on a first control signal input; and based on the oscillating input signal, generate an N-phase output signal having a frequency f-divided-by-M, wherein M is an integer and adjacent phases of the N-phase output signal are separated by 360-divided-by-(M-times-Q) degrees. The divider circuit can also include a control circuit configured to receive a control input and, based on the control input: provide the first control signal to the multi-phase generator circuit; and select a particular phase of the N-phase output signal. Exemplary embodiments also include a phase-locked loop circuits, transceiver circuits, radio stations, and methods of frequency-dividing an oscillating signal.

Electronic circuit, phase-locked loop, transceiver circuit, radio station and method of frequency dividing

A digital solution for phase control of an output of a phase-locked loop (PLL) () is provided to achieve a desired phase shift at the output of the PLL (). To that end, a fraction of the pulses of a PLL feedback signal are time shifted to achieve a desired average time shift associated with the desired phase shift. As a result, a desired phase shift is generated at the output of the PLL (), while a desired devisor of the feedback signal is maintained on average. The resulting digital solution provides highly accurate phase control.

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Lund, Sweden

Tony Påhlsson