Abstract: The transmission and reception group delay in a front end structure of a mobile device may be determined using closed loop calibration. The closed loop may be a near field radiated closed loop between pairs of antennas in an antenna array of the mobile device. The delay based on time of transmission and time of reception may be measured for a plurality of pairs of antennas, from which the transmit and receive group delay within a single path may be determined. The propagation delay of the signal between antennas may be included in the group delay calibration for increased accuracy. In another implementation, a conducted closed loop, e.g., in the transceiver or in a radio frequency switching network may be used to calibrate the group delay. Pre-characterization of the delay caused by components between the closed loop and antennas may be included in the group delay calibration for increased accuracy.

Abstract: Disclosed are techniques for reporting a group delay-per-frequency lookup table for transmit and receive beams. In an aspect, a user equipment (UE) receives, from a transmission-reception point (TRP), a first downlink reference signal on at least one downlink reference signal resource using a downlink receive beam, transmits, to the TRP, an uplink reference signal on at least one uplink reference signal resource using an uplink transmit beam, determines a parameter representing a difference between a reception time of the first downlink reference signal and a transmission time of the uplink reference signal, transmit the parameter to a network entity, and transmits, to the network entity, a first lookup table or an identifier of the first lookup table, wherein the first lookup table represents per-frequency group delay information for the downlink receive beam and/or the uplink transmit beam.

Abstract: The transmission and reception group delay in a front end structure of a mobile device may be determined using closed loop calibration. The closed loop may be a near field radiated closed loop between pairs of antennas in an antenna array of the mobile device. The delay based on time of transmission and time of reception may be measured for a plurality of pairs of antennas, from which the transmit and receive group delay within a single path may be determined. The propagation delay of the signal between antennas may be included in the group delay calibration for increased accuracy. In another implementation, a conducted closed loop, e.g., in the transceiver or in a radio frequency switching network may be used to calibrate the group delay. Pre-characterization of the delay caused by components between the closed loop and antennas may be included in the group delay calibration for increased accuracy.

Abstract: Disclosed are techniques for reporting a group delay-per-frequency lookup table for transmit and receive beams. In an aspect, a user equipment (UE) receives, from a transmission-reception point (TRP), a first downlink reference signal on at least one downlink reference signal resource using a downlink receive beam, transmits, to the TRP, an uplink reference signal on at least one uplink reference signal resource using an uplink transmit beam, determines a parameter representing a difference between a reception time of the first downlink reference signal and a transmission time of the uplink reference signal, transmit the parameter to a network entity, and transmits, to the network entity, a first lookup table or an identifier of the first lookup table, wherein the first lookup table represents per-frequency group delay information for the downlink receive beam and/or the uplink transmit beam.

Abstract: Phase variations between a transmitter (TX) waveform and a receiver (RX) waveform produced by a TX Phase-Locked-Loop (PLL) and a RX PLL, respectively, is a source of error in processing delay calibration used, e.g., in Round Trip Time (RTT) estimation. While a TX waveform and a RX waveform have a constant phase delay while in steady state conditions, during transient times, e.g., at start up or reset, the phase delay may vary by as much as ±180°, which at baseband frequencies of 50 MHz, introduces a random delay variations of as much as ±10 nsec, which is undesirable for fine position estimation using RTT. The phase delay variation between the TX waveform and RX waveform may be reduced or eliminated using a phase correction signal generated using the output signals of the TX PLL and RX PLL.

Abstract: Phase variations between a transmitter (TX) waveform and a receiver (RX) waveform produced by a TX Phase-Locked-Loop (PLL) and a RX PLL, respectively, is a source of error in processing delay calibration used, e.g., in Round Trip Time (RTT) estimation. While a TX waveform and a RX waveform have a constant phase delay while in steady state conditions, during transient times, e.g., at start up or reset, the phase delay may vary by as much as ±180°, which at baseband frequencies of 50 MHz, introduces a random delay variations of as much as ±10 nsec, which is undesirable for fine position estimation using RTT. The phase delay variation between the TX waveform and RX waveform may be reduced or eliminated using a phase correction signal generated using the output signals of the TX PLL and RX PLL.

Abstract: A side-tone circuit comprises a microphone configured to generate a reverse link audio signal and a side-tone noise suppressor. The side tone noise suppressor is configured to receive the reverse link audio signal, suppress noise in the received reverse link audio signal, and output a noise suppressed side-tone signal. The side-tone noise circuit also includes a speaker configured to receive the noise suppressed audio signal and communicate it to a user.

Abstract: An apparatus for audio processing including a first device (e.g., a multiplier, digital signal gain module, etc.) adapted to apply a gain to a first digital audio signal to generate a second digital audio signal; a second device (e.g., a digital-to-analog converter (DAC), etc.) adapted to generate an analog audio signal from the second digital audio signal; a third device (e.g., a detector, sensor, user interface, etc.) adapted to generate an audio characteristic signal related to a characteristic of the first or second digital audio signal, or the analog audio signal; and a fourth device (e.g., a controller, control module, etc.) adapted to control the gain of the first device based on a first function of the audio characteristic signal, and control a power supplied to the second device based on a second function of the audio characteristic signal.

Abstract: A stereo headset interface that is compatible with mono for an audio playback device. A load in series between an audio output from a stereo headset driver and a ground of a mono headset plug prevents the audio output from being grounded when a mono headset plug is inserted into the stereo headset jack of the playback device. A second load in series between a second audio output and the mono headset plug balances the first and second audio outputs from the stereo headset driver.

Abstract: A signal conditioning circuit is described which can facilitate dual mode use of a connector circuit, e.g., audio mode or data mode. In other words, a headset or alternatively, a data interface may be coupled to the connector circuit and signal conditioning circuit, depending on the mode of the device. In accordance with this disclosure, the signal conditioning circuit operates in audio mode without the need for conventional blocking capacitors in the speaker channels. Moreover, in some embodiments, the signal conditioning circuit also provides backwards compatibility with conventional connector circuits that include such blocking capacitors.

Abstract: A stereo headset interface that is compatible with mono for an audio playback device. A load in series between an audio output from a stereo headset driver and a ground of a mono headset plug prevents the audio output from being grounded when a mono headset plug is inserted into the stereo headset jack of the playback device. A second load in series between a second audio output and the mono headset plug balances the first and second audio outputs from the stereo headset driver.

Abstract: A side-tone circuit comprises a microphone configured to generate a reverse link audio signal and a side-tone noise suppressor. The side tone noise suppressor is configured to receive the reverse link audio signal, suppress noise in the received reverse link audio signal, and output a noise suppressed side-tone signal. The side-tone noise circuit also includes a speaker configured to receive the noise suppressed audio signal and communicate it to a user.