A system and method for analog estimation of a spectral correlation function (SCF) provides a photonic carrier to generate a signal comb and offset comb, each comprising N comb tones separated by respective repetition rates ΔF and ΔF+δF. The signal and offset combs are amplitude-modulated according to an inbound RF signal of interest and filtered via periodic optical filters to produce a sequence of N Fourier components of the signal comb and N Fourier components of the offset comb, each filtered signal comb component overlapping with a filtered offset comb component. In-phase/quadrature (I/Q) components of the products of each component of the complex conjugate of the filtered offset comb and the overlapping counterpart of the filtered signal comb are generated in an optical receiver and digitized into slices of the SCF at a fixed time instance and center frequency, correlated at various cyclic separations α.

Provided is a device comprising a frequency demodulator and an amplitude demodulator. The device is configured to use, in a first mode, both the frequency demodulator and the amplitude demodulator in parallel and to activate a radio frequency identification (RFID) card mode or a Qi charger mode based on results provided by said demodulators.

This application relates to a tamper-resistant datalink communications system. The system may include a ground-based communications module configured to be coupled to a radio controller configured to remotely control a drone comprising one or more actuators and a remote-mounted communications module configured to communicate data with the ground-based communications module. The ground-based communications module may include a ground processor configured to: receive a plurality of first signals modulated with a first modulation scheme from the radio controller, convert the plurality of first signals to a second signal modulated with a second modulation scheme different from the first modulation scheme, and generate a plurality of second duplicated signals comprising two or more duplicate signals of the second signal. The ground-based communications module may also include a plurality of ground transmitters configured to operate in different frequencies and respectively transmit the plurality of second duplicated signals to the remote-mounted communications module.

Optimized continuous time linear equalization (CTLE) circuit parameters for a received signal are found using an iterative search process. The received signal is repeatedly sampled by an analog-to-digital converter (ADC). Certain samples containing interference that cannot be cancelled by a CTLE in the sampled series are filtered out (discarded). The remaining samples are used to generate, over a selected evaluation window, a histogram of the sampled values. This histogram is used to calculate a figure of merit for the current CTLE parameter settings. The figures of merit for various CTLE parameter settings are compared to find the set of CTLE parameter settings that optimize the figure of merit and by extension, optimize the CTLE circuitry's performance at equalizing the received signal.

Optimized continuous time linear equalization (CTLE) circuit parameters for a received signal are found using an iterative search process. The received signal is repeatedly sampled by an analog-to-digital converter (ADC). Certain samples containing interference that cannot be cancelled by a CTLE in the sampled series are filtered out (discarded). The remaining samples are used to generate, over a selected evaluation window, a histogram of the sampled values. This histogram is used to calculate a figure of merit for the current CTLE parameter settings. The figures of merit for various CTLE parameter settings are compared to find the set of CTLE parameter settings that optimize the figure of merit and by extension, optimize the CTLE circuitry's performance at equalizing the received signal.

Logic may define one or more wake-up preambles suitable for high data rates for a wake-up radio (WUR) packet. Logic may define wake-up preamble with different counts of symbols. Logic may generate a wake-up preamble as an on-off keying (OOK) signal. Logic may generate and receive a wake-up preamble that signals a high data transmission rate with respect to data rates defined for WUR packet transmissions. Logic may generate or receive a preamble that signals a rate of transmission of the WUR packet as 250 kilobits per second. Logic may transmit or receive bits of the wake-up preamble as two microsecond orthogonal frequency-division multiplexing (OFDM) based pulses, wherein each two microsecond OFDM based pulse is based on a 32-point Fast Fourier Transform (FFT) in a 20 Megahertz (MHz) bandwidth, with a subcarrier spacing of 625 Kilohertz (KHz) to produce six subcarriers in a four MHz bandwidth.

Logic may define one or more wake-up preambles suitable for high data rates for a wake-up radio (WUR) packet. Logic may define wake-up preamble with different counts of symbols. Logic may generate a wake-up preamble as an on-off keying (OOK) signal. Logic may generate and receive a wake-up preamble that signals a high data transmission rate with respect to data rates defined for WUR packet transmissions. Logic may generate or receive a preamble that signals a rate of transmission of the WUR packet as 250 kilobits per second. Logic may transmit or receive bits of the wake-up preamble as two microsecond orthogonal frequency-division multiplexing (OFDM) based pulses, wherein each two microsecond OFDM based pulse is based on a 32-point Fast Fourier Transform (FFT) in a 20 Megahertz (MHz) bandwidth, with a subcarrier spacing of 625 Kilohertz (KHz) to produce six subcarriers in a four MHz bandwidth.

Methods and systems are described for measuring a vertical opening of a signal eye of a pulse amplitude modulated (PAM) signal received over a channel to determine a vertically-centered voltage decision threshold of a sampler receiving a sampling clock, determining channel-characteristic parameters indicative of a frequency response of the channel, determining a correctional vernier value from the channel-characteristic parameters, and generating a horizontally-centered voltage decision threshold that introduces a horizontal sampling offset in the sampling clock in a direction closer to a horizontal center of the signal eye by combining the vertically-centered voltage decision threshold and the correctional vernier value.

Methods and systems are described for measuring a vertical opening of a signal eye of a pulse amplitude modulated (PAM) signal received over a channel to determine a vertically-centered voltage decision threshold of a sampler receiving a sampling clock, determining channel-characteristic parameters indicative of a frequency response of the channel, determining a correctional vernier value from the channel-characteristic parameters, and generating a horizontally-centered voltage decision threshold that introduces a horizontal sampling offset in the sampling clock in a direction closer to a horizontal center of the signal eye by combining the vertically-centered voltage decision threshold and the correctional vernier value.

Messages are transmitted in closely-spaced subcarriers in 5G and 6G, configured so that each subcarrier signal is orthogonal to the adjacent subcarrier signals. However, many effects can penetrate that orthogonality—distortion, interference, frequency variations, amplitude variations, crosstalk, etc.—collectively termed energy spill-over. To combat this problem, a receiver can determine the total energy spill-over into adjacent subcarriers by measuring a residual signal in a subcarrier with no transmission, adjacent to another subcarrier with a known transmission. The receiver can measure the amplitude, phase, temporal or spectral properties, and so forth of the residual signal. The receiver can then correct the message during signal processing, by calculating a function of the residual signal and subtracting it from each digitized subcarrier signal of a message. This can largely restore the inter-subcarrier orthogonality, improving messaging reliability while avoiding message faults and costly retransmissions.