Abstract: Certain aspects of the present disclosure generally relate to jamming detection for radio frequency (RF) front-end circuitry. For example, certain aspects provide an apparatus having a first counter configured to count a number of times that a power of a reception signal exceeds a first threshold. The apparatus also includes a second counter configured to count a number of measurements of the power of the reception signal. The apparatus further includes control logic having a first input coupled to an output of the first counter and having a second input coupled to an output of the second counter. The control logic is configured to determine an amount of jamming over a measurement window based on the number of times that the power of the reception signal exceeds the first threshold and on the number of measurements.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a receiver device may identify an analog to digital converter (ADC) clipping rate for one or more measurement windows. The receiver device may modify, based at least in part on a determination that the ADC clipping rate does not satisfy a threshold, a low noise amplifier (LNA) gain value to be used by the receiver device. The receiver device may receive a signal using the modified LNA gain value. Numerous other aspects are provided.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a receiver device may identify an analog to digital converter (ADC) clipping rate for one or more measurement windows. The receiver device may modify, based at least in part on a determination that the ADC clipping rate does not satisfy a threshold, a low noise amplifier (LNA) gain value to be used by the receiver device. The receiver device may receive a signal using the modified LNA gain value. Numerous other aspects are provided.

Abstract: Methods, systems, and devices for wireless communications are described. One example includes calculating one or more first channel capacities for each precoder hypothesis of a first subset of precoder hypotheses and selecting a first precoder hypothesis of the first subset of precoder hypotheses using the calculated first channel capacities. The example also includes selecting a second subset of precoder hypotheses based on the first precoder hypothesis, calculating one or more second channel capacities for each precoder hypothesis of the second subset of precoder hypotheses, and selecting a second precoder hypothesis of the second subset of precoder hypotheses using the calculated second channel capacities. The example also includes selecting grouping co-phase factors based at least in part on the first precoder hypothesis or the second precoder hypothesis and transmitting a first precoding matrix indicator that indicates a first precoder index based on the one or more grouping co-phase factors.

Abstract: Methods, systems, and devices for channel estimation in a location tracking system are described. The methods, system, and devices may include tools and techniques for determining and/or designing perfect or semi-perfect sequences (including preamble sequences) for implementation in a location tracking system. Sequences having 2's exponent dimensionality, such as ternary sequences, may be determined and employed, which may help reduce implementation complexity and/or operating power consumption. Sequences may be determined using mean square error and/or maximum autocorrelation peak performance metrics.

Abstract: Described are a system and method for correcting a receiver frequency at a receiver to enhance detection of arrival of a wirelessly transmitted message. In particular, a frequency offset between receiver frequency and a carrier frequency may be estimated based, at least in part, on an autocorrelation of a bit sequence in a received message.

Abstract: A ranging procedure is performed using interference cancellation using preamble messages from a plurality of objects, each of which includes a pre-defined orthogonal design coded modulation patterns. A channel for an object may be estimated using the pre-defined orthogonal design coded modulation patterns in the preamble messages received from objects to remove interference of the preamble message received from other objects. A range to an object may be determined based on a determined delay in the preamble message from that object. The range may be used to assist in determining the position of the object. The pre-defined preamble message may be transmitted by receiving a schedule for an access point in a network for a ranging procedure and periodically transmitting a pre-defined preamble message for the ranging procedure, the pre-defined preamble message includes an orthogonal design coded modulation pattern.

Abstract: Methods, systems, and devices are described that provide for wireless searching in a location tracking environment. The methods, systems, and/or devices may include tools and techniques that provide for analyzing requests for location data of an entity and preparing a response set based on the request and the available tags. Response sets may include location data for the requested entity, location data for a second entity different from the requested entity, a clarifying question, or a null value. Multiple requests may be received and an order of evaluation will be determined. Results may be adjusted for individual users. Categories as well as individual entities may be searched. Upon receiving a response set, a mobile device may display directions to the identified entity.

Abstract: Methods, systems, and devices for maximizing signal to interference plus noise ratio of a channel in a location tracking system. The methods, systems, and device may include tools and techniques for minimizing interference from adjacent samples at a receive filter, may include relaxing constraints at a transmitter. A receive filter or set of receive, or both, filters may be determined and utilized by specifying and or determining various transmitter, receiver, and channel characteristics. The receive filter and set of filters may be determined through an iterative approach involving one or more solution metrics.

Abstract: Methods, systems, and devices for detecting earliest channel path and/or determining time of arrival of signals in location tracking systems are described. An ultra-wideband (UWB) signal may be received from a tag. A noise estimation level above which the UWB signal is detectable may be determined using a noise estimation metric. A channel impulse response (IR) energy level may be determined using a channel energy metric. A leading edge window of the UWB signal may be identified. The leading edge window may be based on, at least in part, the noise estimation level and the channel IR energy level.

Abstract: A ranging procedure is performed using interference cancellation using preamble messages from a plurality of objects, each of which includes a pre-defined orthogonal design coded modulation patterns. A channel for an object may be estimated using the pre-defined orthogonal design coded modulation patterns in the preamble messages received from objects to remove interference of the preamble message received from other objects. A range to an object may be determined based on a determined delay in the preamble message from that object. The range may be used to assist in determining the position of the object. The pre-defined preamble message may be transmitted by receiving a schedule for an access point in a network for a ranging procedure and periodically transmitting a pre-defined preamble message for the ranging procedure, the pre-defined preamble message includes an orthogonal design coded modulation pattern.

Abstract: Methods, systems, and devices for channel estimation in a location tracking system are described. The methods, system, and devices may include tools and techniques for determining and/or designing perfect or semi-perfect sequences (including preamble sequences) for implementation in a location tracking system. Sequences having 2's exponent dimensionality, such as ternary sequences, may be determined and employed, which may help reduce implementation complexity and/or operating power consumption. Sequences may be determined using mean square error and/or maximum autocorrelation peak performance metrics.

Abstract: Methods, systems, and devices for channel estimation and/or earliest path detection in a location tracking system are described. The described tools and techniques may involve accumulation of energy of multiple copies of a periodic sequence, which may be contained and/or associated with a signal transmitted from a location tracking tag. One or more access points within the location tracking system may receive and process multiple copies of the sequence, employing period-wise coherent accumulation, and estimate an earliest path, or a corresponding delay associated with an earliest path, of the sequence. The access point(s) may transmit information related to the earliest path, including the corresponding delay, to a tracking management server, which may use the information to estimate and/or determine a location of a tag.

Abstract: Methods, systems, and devices for maximizing signal to interference plus noise ratio of a channel in a location tracking system. The methods, systems, and device may include tools and techniques for minimizing interference from adjacent samples at a receive filter, may include relaxing constraints at a transmitter. A receive filter or set of receive, or both, filters may be determined and utilized by specifying and or determining various transmitter, receiver, and channel characteristics. The receive filter and set of filters may be determined through an iterative approach involving one or more solution metrics.

Abstract: Methods, systems, and devices are described for maximizing transmit power of an ultra-wideband (UWB) pulse. A spectral mask and a spectral efficiency may be identified. A set of transmit filter coefficients may be generated at a fraction of a carrier frequency. The set of transmit filter coefficients may be based at least in part on the identified spectral mask and spectral efficiency. The UWB pulse may be transmitted with a shape defined at least in part by the set of transmit filter coefficients.

Abstract: Methods, systems, and devices for detecting earliest channel path and/or determining time of arrival of signals in location tracking systems are described. An ultra-wideband (UWB) signal may be received from a tag. A noise estimation level above which the UWB signal is detectable may be determined using a noise estimation metric. A channel impulse response (IR) energy level may be determined using a channel energy metric. A leading edge window of the UWB signal may be identified. The leading edge window may be based on, at least in part, the noise estimation level and the channel IR energy level.

Abstract: Wireless communication devices are disclosed that are capable of selecting and changing signal polarities depending on channel conditions in order to improve or optimize communication therebetween. When a first polarization direction is deemed inadequate, the devices can switch to communicating via a second polarization. In addition, information relating to received signal qualities in the different polarizations can be stored in each device to allow for quick and efficient exchanges between configurations. Finally, when conditions warrant, the devices can enter a dynamic polarization configuration in which signal polarizations are switched rapidly so as to enjoy benefits of diversity.

Abstract: Disclosed are various embodiments of pairing with a directional code sequence. In one embodiment a method includes discovering that a user device is within proximity of a pairing device. A directional code sequence based upon variations in the position of the user device is obtained and a communication link is established between the user device and the pairing device in response to the directional code sequence. In another embodiment, a system includes a user device and a pairing device configured to establish a communication link with the user device in response to a sequence of position variations of the user device. In another embodiment, a method includes obtaining a sequence of characters corresponding to a directional code sequence from a pairing device and transmitting a signal from a user device to the pairing device from a sequence of positions corresponding to the sequence of characters.

Abstract: A signal acquisition system efficiently acquires a transmitted signal even at very low power. The system may synchronize to a preamble structure in the transmitted signal and, for example, determine timing parameters that locate the preamble with respect to system timing or other clock references. The system is particularly effective at acquiring weak power signals and is also robust against significant noise and other impairments, and therefore improves the ability of a receiving device that incorporates the signal acquisition system to acquire the signal and establish communication with other devices.

Abstract: A method and system are provided in which a first device may directionally transmitting signals to a second device utilizing beamforming operations on multiple antennas. The first device may receive signals from the second device to establish an anonymous directional peer-to-peer wireless communication link with the second device. The transmitted signals may comprise a request-to-send (RTS) signal and the received signals may comprise a clear-to-send (CTS) signal. In some instances, the direction in which the transmitted signals are sent may be adjusted by changing the weights in the beamforming operation and/or by rotating the plurality of antennas. The transmitted signals may comprise an association identification (ID) corresponding to the first device, which may be embedded in a preamble or other portion of a frame structure. When the link is established, user information, such as profile information, for example, and/or messages may be sent from one device to the other.