A method of operating a VR or AR head mounted display (HMD) system includes obtaining a video performance parameter for a video signal, selecting a clock frequency for video data transfer within the HMD system based on the video performance parameter, detecting one or more available frequency bands for a wireless data connection between a host device and the HMD system, and selecting a frequency band from the one or more available frequency bands for the wireless data connection, based on a predetermined connection suitability parameter for the one or more available frequency bands and based on the selected clock frequency for video data transfer within the HMD system. The method further includes establishing a wireless connection between the host device and the HMD system over the selected frequency band.

In one example, a communications circuit processes an amplitude modulated signal by using a first circuit having signal paths to process an amplitude modulated signal as represented by an in-phase component and by a quadrature component, and by using a second circuit to discern random noise pulses from the quadrature component of the amplitude modulated signal. In response, the second circuit generates an estimate of overall noise representing the random noise pulses in the amplitude modulated signal. In the above and more specific examples, the random noise pulses may appear as pulses which overlap with, in terms of time and bandwidth of frequency spectrum, information of the amplitude modulated signal, and the first and second circuits may be part of an RF radio receiving the amplitude modulated signal from an antenna.

Multi-drop communications channels can have significantly deep notches in their frequency response causing a corresponding limitation of the effective data transmission rate. A special time-ordered coding method is described which results in the emitted spectrum of the data stream transmitted into the channel having a notch at the same frequency as the notch in the channel frequency response, permitting channel receivers to successfully decode the transmitted data stream. The described coding method may be applied at various multiples of the channel notch frequency to support different throughput rates, and may be combined with other coding techniques such as group or vector signaling codes.

According to some embodiments, in a multi-user detection (MUD) receiver, a method for identifying a beam which produces a specific signal-to-interference-plus-noise ratio (SINR) can include: determining a maximum output SINR; determining beam weights to achieve a target SINR using the determined maximum output SINR; applying the beam weights to one or more received signals to generate a beamformed signal having the target SINR, one or more of the received signals having a signal of interest (SOI), one or more interfering signals, and noise; and providing the beamformed signal to a multi-user detection unit to recover the SOI.

Systems, methods, and circuitries are provided for resonator-based local oscillator signal generation for receiving self-interference signals. An interference cancellation system for a transceiver includes a resonator configured to generate a high-frequency signal and a local oscillator circuitry. The local oscillator circuitry includes a digital-to time converter configured to receive the high-frequency signal and, in response, generate a clock signal for receiving an interfering signal having an interference frequency. Digital cancellation circuitry is configured to adapt operation of the transceiver based, at least in part, on the received interfering signal.

A detector circuit includes: a squaring circuit configured to receive an output of a power amplifier of a radio transmitter and to produce an output current, the output of the power amplifier including: a desired tone; a local oscillator leakage tone; and an image tone, and the output current of the squaring circuit including: a direct current (DC) component including a function of the desired tone and an alternating current (AC) component; and a DC current absorber electrically connected to an output terminal of the squaring circuit, the DC current absorber being configured to filter out the DC component of the output current of the squaring circuit to produce a filtered output of the squaring circuit, the filtered output including the AC component including functions of the local oscillator leakage tone and the image tone.

Systems, methods, and circuitries are disclosed for performing self-interference cancellation in a transceiver. In one example, a self-interference cancellation system includes a cancellation signal circuitry, cancellation circuitry, down-conversion circuitry, and an LO derivation circuitry. The cancellation signal circuitry is configured to use a cancellation transmit (TX) local oscillator (LO) signal to up-convert a baseband transmit leakage replica signal to generate a cancellation signal. The cancellation circuitry is configured to combine the cancellation signal with a received signal to generate a corrected received signal. The down-conversion circuitry is configured to use a receive (RX) LO signal to down-convert the corrected received signal to generate a baseband received signal. The LO derivation circuitry is configured to derive the cancellation TX LO signal and the RX LO signal from a common LO signal.

The present disclosure generally relates to the field of receiver structures in radio communication systems and more specifically to passive mixers in the receiver structure and to a technique for converting a first signal having a first frequency into a second signal having a second frequency by using a third signal having a third frequency. A passive mixer for converting a first signal having a first frequency into a second signal having a second frequency by using a third signal having a third frequency comprises a cancellation component for generating a first cancellation signal for cancelling second order intermodulation components by superimposing the first signal weighted by a cancellation value on the third signal; and a mixing component having a first terminal for receiving the first signal, a second terminal for outputting the second signal, and a third terminal for receiving the first cancellation signal, wherein the mixing component is adapted to provide the second signal as output at the second terminal by mixing the first signal provided as input at the first terminal and the first cancellation signal provided as input at the third terminal.

The present disclosure generally relates to the field of receiver structures in radio communication systems and more specifically to passive mixers in the receiver structure and to a technique for converting a first signal having a first frequency into a second signal having a second frequency by using a third signal having a third frequency. A passive mixer for converting a first signal having a first frequency into a second signal having a second frequency by using a third signal having a third frequency comprises a cancellation component for generating a first cancellation signal for cancelling second order intermodulation components by superimposing the first signal weighted by a cancellation value on the third signal; and a mixing component having a first terminal for receiving the first signal, a second terminal for outputting the second signal, and a third terminal for receiving the first cancellation signal, wherein the mixing component is adapted to provide the second signal as output at the second terminal by mixing the first signal provided as input at the first terminal and the first cancellation signal provided as input at the third terminal.

An apparatus and a method are provided in which a processor of a receiving apparatus regenerates time domain samples of an interfering data numerology from frequency domain received signals. The processor performs FFT, with a size corresponding to a desired data numerology, on the regenerated time domain samples to generate an interfering numerology cancellation signal. The processor subtracts the interfering numerology cancellation signal from a frequency domain received signal of the desired data numerology.