Abstract: This document describes techniques and systems for indoor localization using Bluetooth high-accuracy distance measurement (HADM). In examples, the described systems and techniques perform a signal-strength scan to identify multiple anchor points and then pair, based on the signal-strength scan, the tagged device with a first anchor point of the identified anchor points. A HADM time slot is set for the first anchor point and at least two additional anchor points of the identified anchor points. A HADM event is initiated, the HADM event including sending a HADM ping and receiving HADM responses from two or more of the identified anchor points. Based on at least a time of receipt of HADM responses received from the two or more of the identified anchor points, the location of the tagged device is calculated.

Abstract: In general, the subject matter described in this disclosure can be embodied in methods, devices, and program products for selecting a wireless transmission mechanism. A computing device receives a request to begin a full-duplex voice communication session with a remote computing system. The computing device identifies that it has wirelessly connected to both a WWAN access point and a WLAN access point. The computing device determines whether a level of non-voice session data that is queued for transmission or receipt by the computing device falls beneath a threshold level of data, and as a result, switches to using a single one of multiple WLAN radio chains. The computing device communicates data over the single one of the multiple WLAN radio chains, including voice session data from the full-duplex voice communication session.

Abstract: In general, the subject matter described in this disclosure can be embodied in methods, devices, and program products for selecting a wireless transmission mechanism. A computing device receives a request to begin a full-duplex voice communication session with a remote computing system. The computing device identifies that it has wirelessly connected to both a WWAN access point and a WLAN access point. The computing device determines whether a level of non-voice session data that is queued for transmission or receipt by the computing device falls beneath a threshold level of data, and as a result, switches to using a single one of multiple WLAN radio chains. The computing device communicates data over the single one of the multiple WLAN radio chains, including voice session data from the full-duplex voice communication session.

Abstract: In general, the subject matter described in this disclosure can be embodied in methods, devices, and program products for selecting a wireless transmission mechanism. A computing device receives a request to begin a full-duplex voice communication session with a remote computing system. The computing device identifies that it has wirelessly connected to both a WWAN access point and a WLAN access point. The computing device determines whether a level of non-voice session data that is queued for transmission or receipt by the computing device falls beneath a threshold level of data, and as a result, switches to using a single one of multiple WLAN radio chains. The computing device communicates data over the single one of the multiple WLAN radio chains, including voice session data from the full-duplex voice communication session.

Abstract: A method for in-phase-quadrature (I-Q) imbalance calibration is described. A signal is transmitted by a first transmitter in a first system. The signal includes a constant value. The signal is received at a second receiver in a second system. An I-Q imbalance is estimated for the second receiver based on the received signal.

Abstract: Systems and methods are disclosed for compensating I-Q imbalance in a wireless receiver. The receiver may employ a quadrature downconverter configured to receive an RF signal input and output an in-phase component and a quadrature component at an IF, an IF rotation block configured to downconvert the in-phase and quadrature components to baseband and an I-Q correction block configured to compensate for an I-Q imbalance in the received signal, wherein the I-Q correction block is positioned downstream from the IF rotation block in the signal path. Performing the I-Q correction after conversion to baseband may allow the compensation calculations to operate at a reduced digital rate. Similarly, digitally adjusting the gain of the signal prior to I-Q compensation may reduce the number of bits that are manipulated during the compensation process. These features may represent significant efficiencies as compared to I-Q corrections performed at IF.

Abstract: A method for in-phase-quadrature (I-Q) imbalance calibration is described. A signal is transmitted by a first transmitter in a first system. The signal includes a constant value. The signal is received at a second receiver in a second system. An I-Q imbalance is estimated for the second receiver based on the received signal.

Abstract: Systems and apparatus are disclosed for a target device to detect a trigger from an initiating device. One implementation includes a wireless device configured to correlate a received waveform with a target waveform, compare a result of the correlation to a threshold and output a first signal based on the comparison of the result and the threshold. The apparatus may also be configured to generate a sequence of bits by demodulating at least a portion of the received waveform in response to receiving the first signal, to compare in parallel a plurality of circularly rotated versions of a target sequence of bits with the demodulated sequence of bits, and to combine the results of the comparisons and output a second signal when the combined comparisons indicate that the demodulated sequence of bits corresponds to the target sequence of bits.

Abstract: Systems and methods are disclosed for compensating I-Q imbalance in a wireless receiver. The receiver may employ a quadrature downconverter configured to receive an RF signal input and output an in-phase component and a quadrature component at an IF, an IF rotation block configured to downconvert the in-phase and quadrature components to baseband and an I-Q correction block configured to compensate for an I-Q imbalance in the received signal, wherein the I-Q correction block is positioned downstream from the IF rotation block in the signal path. Performing the I-Q correction after conversion to baseband may allow the compensation calculations to operate at a reduced digital rate. Similarly, digitally adjusting the gain of the signal prior to I-Q compensation may reduce the number of bits that are manipulated during the compensation process. These features may represent significant efficiencies as compared to I-Q corrections performed at IF.