A radio receiver is provided for low-power detection of a radio signal, wherein said receiver is configured to receive a radio signal over a radio network; convert at least part of the received radio signal into a sequence of samples; compare the similarity of a first part of the sequence and a second part of the sequence, wherein the first part and the second part are of equal length; and in response to said similarity being greater than a similarity threshold: detect a phase difference between the first part of the sequence and the second part of the sequence; calculate a frequency offset between a frequency of the received radio signal and an expected frequency of the received radio signal using said phase difference; and use said calculated frequency offset to attempt full access to the radio network.

A radio node (14) is configured to perform frequency offset estimation. The radio node (14) in this regard receives a first set (22-1) of reference symbols of a reference signal during respective time resources, and determines a first frequency offset estimate (26-1) using the first set (22-1) of reference symbols. The radio node (14) also receives a second set (22-2) of 5 reference symbols of the reference signal during respective time resources, e.g., using the same local oscillator frequency for down conversion as with the first set (22-1). The radio node (14) further determines, based on the first frequency offset estimate (26-1), a second frequency offset estimate (26-2) using the second set (22-2) of reference symbols. In some embodiments, the radio node (14) determines a third frequency offset estimate as a sum of the first and 10 second frequency offset estimates, and tunes a local oscillator frequency, or performs frequency offset compensation, based on the third frequency offset estimate.

A radio receiver is provided for low-power detection of a radio signal, wherein said receiver is configured to receive a radio signal over a radio network; convert at least part of the received radio signal into a sequence of samples; compare the similarity of a first part of the sequence and a second part of the sequence, wherein the first part and the second part are of equal length; and in response to said similarity being greater than a similarity threshold: detect a phase difference between the first part of the sequence and the second part of the sequence; calculate a frequency offset between a frequency of the received radio signal and an expected frequency of the received radio signal using said phase difference; and use said calculated frequency offset to attempt full access to the radio network.

A method for determining an angle of arrival (AOA) of a received signal is disclosed, comprising: generating a baseband information signal by mixing a received signal with a local oscillator (LO) signal, the received signal being an in-phase signal and quadrature signal uncorrelated with each other and derived from different input data sets; obtaining baseband signal samples of the baseband information signal having an in-phase signal sample and a quadrature signal sample; determining a transmitter phase offset based on an estimated correlation between the in-phase signal samples and the quadrature signal samples; performing a plurality of phase measurements using a plurality of antennas to obtain a plurality of phase measurements; correcting the plurality of phase measurements based on the transmitter phase offset to produce a plurality of corrected phase measurement; and calculating an AOA of the received signal based on the difference between the plurality of corrected phase measurements.

The disclosure relates to determining a carrier phase shift between a first transceiver (101) and a second transceiver (103), each transceiver comprising a local oscillator for generating a carrier signal, an example method for which comprises: the first transceiver (101) generating and transmitting a first continuous wave carrier signal packet (201); the second transceiver (103) receiving the first continuous wave carrier signal packet (201); the second transceiver (103) calculating a first phase correction (PCT.sub.B) based on a comparison between the received first continuous wave carrier signal packet (201) and a local oscillator carrier signal at the second transceiver (103); the second transceiver (103) generating and transmitting a second continuous wave carrier signal packet (203); the first transceiver (101) receiving the second continuous wave carrier signal packet (203); the first transceiver (101) calculating a second phase correction (PCT.sub.A) based on a comparison between the received second continuous wave carrier signal packet (203) and a local oscillator signal at the first transceiver (101); and the first transceiver (101) calculating the carrier phase shift (θ.sub.1W) from an average of the first and second phase corrections (PCT.sub.B, PCT.sub.A), wherein the local oscillator of the first transceiver (101) is deactivated after transmitting the first continuous wave carrier signal packet (201) and reactivated before receiving the second continuous wave carrier signal packet (203).

A radio frequency (RF) transceiver includes a reference signal source to generate a reference signal, a local RF source to generate a local RF signal and a mixed-signal phase/frequency detector to compare the reference signal to the local RF signal, and to generate a difference signal from the comparison, wherein the difference signal comprises a modulation component and an error component. The transceiver also includes a receiver front end to receive and downconvert an angle-modulated RF signal to a baseband signal, a quadrature modulator configured to angle-modulate the reference signal source with the baseband signal.

According to at least one example embodiment, a method and corresponding apparatus for controlling power in a multi-core processor chip include: accumulating, at a controller within the multi-core processor chip, one or more power estimates associated with multiple core processors within the multi-core processor chip. A global power threshold is determined based on a cumulative power estimate, the cumulative power estimate being determined based at least in part on the one or more power estimates accumulated. The controller causes power consumption at each of the core processors to be controlled based on the determined global power threshold. The controller may directly control power consumption at the core processors or may command the core processors to do so.

Channel estimation performance depends on the amount of averaging performed by a channel impulse response coherent filter. For half-duplex UEs, which use a single phase locked loop (PLL) for both downlink transmissions and uplink transmissions, averaging may not be performed across downlink subframes before and after uplink subframes if the PLL's phase changes and locks to a random initial value when switching transmission directions. Techniques disclosed herein facilitate estimating the PLL's random initial phase and enable correcting the phase of symbols accordingly. By correcting the phase of the symbols, it is possible to average across symbols before and after a frequency re-tune and/or a transmission direction switch based on the phase correction. This may serve to improve the accuracy of channel estimation. Further techniques disclosed herein may improve the accuracy of Doppler estimations by enabling the inclusion of symbols before and after a frequency re-tuning when performing the Doppler estimation.

Techniques are described for accurate tracking of a radiofrequency (RF) carrier for amplitude-modulated signals in unstable reference clock environments. For example, some embodiments operate in context of clock circuits in devices configured for near-field communication (NFC) card emulation (CE) mode. The clock circuits seek to generate an internal clocking signal by tracking a clock reference, such as an RF carrier. In some cases, the clock reference can unpredictably become unreliable for periods of time, during which continued tracking of the unreliable clock reference can yield appreciable frequency and phase errors in the generated internal clocking signal. Embodiments implement phase delta detection with time limiting to limit the magnitude of such errors in the internal clocking signal introduced while tracking an unreliable clock reference. For example, embodiments force gating of phase tracking signals to limit their duration, thereby limiting impacts of those phase tracking signals on the clock circuit output.

A method for determining and compensating for residual phase noise in a 5G NR DL signal includes converting a block of 5G NR DL time domain signal samples into a block of frequency domain samples for one OFDM data symbol and equalizing and combining the frequency domain samples that fall in an outermost sample accumulation region of each quadrant to form a first composite sample for each quadrant, selecting a signal constellation point belonging to one of the four outermost constellation point decision region as a reference constellation point, rotating at least some of the first composite samples so that the first composite samples are in the same quadrant as the reference constellation point, combining the rotated first composite samples to produce a second composite sample, calculating a phase error between the second composite sample and the reference constellation point, applying phase correction corresponding to the phase error to all subcarriers of the OFDM data symbol, and generating output data from the phase-error-corrected OFDM symbol.