Abstract: A MIMO wireless communication device includes, in part, a first transmit path adapted to transmit a first transmit signal from a first antenna, a second transmit path adapted to transmit a second transmit signal from a second antenna, a first receive path adapted to receive a first receive signal, an interference cancellation circuit and a controller. The cancellation circuit includes a cascaded filter structure each filter including a multitude of filter taps each including a variable element. The controller dynamically varies a value applied to each of the plurality of variable elements in accordance with frequency response characteristics of the variable element to remove a portion of a self-interference and/or cross-talk interference signal present in a signal received by the device.

Abstract: A system for frequency isolation modified self-interference cancellation includes a transmit coupler, that samples an RF transmit signal; an RF self-interference canceller that transforms the sampled RF transmit signal to an RF self-interference cancellation signal; a receive coupler that combines the RF self-interference cancellation signal with the RF receive signal to form a reduced-interference receive signal; and a frequency shifter that frequency shifts only one of the RF transmit signal and the reduced-interference receive signal.

Abstract: In one aspect there is provided a method. The method may include receiving a first analog radio frequency signal including a signal of interest and an interference signal caused by a second analog radio frequency signal transmitted in full duplex over a channel from which the first analog transmission is received; adjusting at least one of the first analog radio frequency signal and a portion of the second analog radio frequency signal to enable at least one of a reduction or an elimination of the interference signal in an output analog radio frequency signal; combining the first analog radio frequency signal and the portion of the second analog radio frequency signal to generate the output analog radio frequency signal characterized by at least the reduction or the elimination of the interference signal included in the output analog radio frequency signal; and providing the output analog radio frequency signal. Related apparatus, systems, methods, and articles are also described.

Abstract: A system that incorporates the subject disclosure may include, for example, determining an interference based on a channel gain for each signal of a group of signals received at a receiver from a group of transmitters. A determination is made of an interference value based on a group of interference signals received at a receiver from a group of transmitters, wherein the interference value is based on channel gains that are estimated for the group of transmitters, and wherein a portion of the interference is self-interference generated from transmitting and receiving at a same time. One of an analog time domain cancellation, a digital time domain cancellation or both, is performed responsive to a determination that the interference value does not satisfy a threshold range of an analog-to-digital converter of the receiver. Other embodiments are disclosed.

Abstract: A backscatter tag communicate device includes, in part, a receiver configured to receive a WiFi packet conforming to a communication protocol defining a multitude of codewords, a mapper configured to map at least a first subset of the multitude of codewords disposed in the packet to a second multitude of codewords defined by the protocol, and a frequency shifter configured to shift a frequency of the second multitude of codewords such that the frequency shifted codewords are characterized by a single sideband spectrum. The communication protocol may be the 802.11b communication protocol. The mapper may optionally map the first subset of the multitude of codewords by changing phases of the first subset of the multitude of codewords.

Abstract: A system for frequency isolation modified self-interference cancellation includes a transmit coupler, that samples an RF transmit signal; an RF self-interference canceller that transforms the sampled RF transmit signal to an RF self-interference cancellation signal; a receive coupler that combines the RF self-interference cancellation signal with the RF receive signal to form a reduced-interference receive signal; and a frequency shifter that frequency shifts only one of the RF transmit signal and the reduced-interference receive signal.

Abstract: A system for self-interference canceller tuning includes a transmit coupler that creates a sampled analog transmit signal; an analog self-interference canceller that transforms the sampled analog transmit signal to an analog self-interference cancellation signal according to a set of tuning parameters, the set of tuning parameters comprising complex weights for a set of taps of the analog self-interference canceller; a tuning circuit that calculates the set of tuning parameters, and applies the set of tuning parameters to the analog self-interference canceller based on component calibration data of the analog self-interference canceller; and a receive coupler that combines the analog self-interference cancellation signal with the analog receive signal to reduce self-interference in the analog receive signal.

Abstract: A system for frequency-isolated self-interference cancellation includes a transmit coupler, that samples an RF transmit signal to create a sampled RF transmit signal having a first RF carrier frequency, an RF self-interference canceller that transforms the sampled RF transmit signal to an RF self-interference cancellation signal, a receive coupler, that combines the RF self-interference cancellation signal with an RF receive signal to form a reduced-interference receive signal, and a frequency shifter.

Abstract: A system for self-interference canceller tuning includes a transmit coupler that creates a sampled analog transmit signal; an analog self-interference canceller that transforms the sampled analog transmit signal to an analog self-interference cancellation signal according to a set of tuning parameters, the set of tuning parameters comprising complex weights for a set of taps of the analog self-interference canceller; a tuning circuit that calculates the set of tuning parameters, and applies the set of tuning parameters to the analog self-interference canceller based on component calibration data of the analog self-interference canceller; and a receive coupler that combines the analog self-interference cancellation signal with the analog receive signal to reduce self-interference in the analog receive signal.

Abstract: A system that incorporates the subject disclosure may include, for example, determining an interference based on a channel gain for each signal of a group of signals received at a receiver from a group of transmitters. A determination is made of an interference value based on a group of interference signals received at a receiver from a group of transmitters, wherein the interference value is based on channel gains that are estimated for the group of transmitters, and wherein a portion of the interference is self-interference generated from transmitting and receiving at a same time. One of an analog time domain cancellation, a digital time domain cancellation or both, is performed responsive to a determination that the interference value does not satisfy a threshold range of an analog-to-digital converter of the receiver. Other embodiments are disclosed.

Abstract: A method for self-interference canceller tuning for a near band radio includes receiving, in a first frequency band, an RF transmit signal of the near band radio; receiving, in a second frequency band, an RF receive signal of the near band radio; generating a self-interference cancellation signal from the RF transmit signal based on a set of configuration parameters; combining the self-interference cancellation signal with the RF receive signal to create a composite receive signal; and adapting the set of configuration parameters based on the compo-site receive signal.

Abstract: A method for tuning an analog self-interference canceller includes detecting a tuning trigger, calculating a set of tuning parameters (the tuning parameters including complex weights for a set of taps of the analog self-interference canceller) in response to the tuning trigger, and applying the set of tuning parameters based on component calibration data.

Abstract: A wireless communication device includes, in part, an analog interference cancellation circuit and a controller. The analog cancellation circuit includes a multitude of delay paths each including a delay element and a variable attenuator. The controller dynamically varies the attenuation level of each of the variable attenuators in accordance with the frequency response characteristic of that attenuator to remove a portion of a self-interference signal present in a signal received by the device. The device measures the frequency response characteristic of the communication channel, used in determining the attenuation levels, via one or more preamble symbols. A second portion of the self-interference signal is removed by the device using a multitude of samples of a transmitted signal and a multitude of samples of a signal to be transmitted.

Abstract: A system that incorporates the subject disclosure may include, for example, determining an interference based on a channel gain for each signal of a group of signals received at a receiver from a group of transmitters. A determination is made as to whether the interference satisfies a threshold range of an analog-to-digital converter of the receiver for each of the group of transmitters. An analog time domain cancellation is performed responsive to a determination that the interference does not satisfy the threshold range, and a digital time domain cancellation is performed responsive to a determination that the interference satisfies the threshold range. Other embodiments are disclosed.

Abstract: Techniques for a motion tracing device using radio frequency signals are presented. The motion tracing device utilizes radio frequency signals, such as WiFi to identify moving objects and trace their motion. Methods and apparatus are defined that can measure multiple WiFi backscatter signals and identify the backscatter signals that correspond to moving objects. In addition, motion of a plurality of moving objects can be detected and traced for a predefined duration of time.

Abstract: A system that incorporates the subject disclosure may include, for example, determining an interference based on a channel gain for each signal of a group of signals received at a receiver from a group of transmitters. A determination is made as to whether the interference satisfies a threshold range of an analog-to-digital converter of the receiver for each of the group of transmitters. An analog time domain cancellation is performed responsive to a determination that the interference does not satisfy the threshold range, and a digital time domain cancellation is performed responsive to a determination that the interference satisfies the threshold range. Other embodiments are disclosed.

Abstract: A system for multi-rate digital self-interference cancellation including a signal component generation system coupled to a digital transmit signal of a communication system that generates a set of signal components from the digital transmit signal; a multi-rate adaptive filter that transforms the set of signal components into a digital self-interference cancellation signal, according to a transform configuration, to form an interference-reduced receive signal; and a transform adaptor that dynamically sets the transform configuration in response to changes in the interference-reduced receive signal.

Abstract: A system that incorporates the subject disclosure may include, for example, determining an interference based on a channel gain for each signal of a group of signals received at a receiver from a group of transmitters. A determination is made as to whether the interference satisfies a threshold range of an analog-to-digital converter of the receiver for each of the group of transmitters. An analog time domain cancellation is performed responsive to a determination that the interference does not satisfy the threshold range, and a digital time domain cancellation is performed responsive to a determination that the interference satisfies the threshold range. Other embodiments are disclosed.

Abstract: Techniques for estimating one or more backscatter signals reflected from one or more objects are disclosed. In one example, a backscatter sensor includes, in part, a receiver for receiving a composite signal comprising one or more reflections of a transmitted signal, each reflection being reflected by one of a plurality of objects; and a processor configured to estimate at least a first backscatter component of the composite signal using a progressive interference cancellation technique. The first backscatter component of the composite signal corresponds to a reflection of the transmitted signal from a first object. In one embodiment, the backscatter sensor includes multiple receivers and/or one or more transmitters.

Abstract: A MIMO wireless communication device includes, in part, a first transmit path adapted to transmit a first transmit signal from a first antenna, a second transmit path adapted to transmit a second transmit signal from a second antenna, a first receive path adapted to receive a first receive signal, an interference cancellation circuit and a controller. The cancellation circuit includes a cascaded filter structure each filter including a multitude of filter taps each including a variable element. The controller dynamically varies a value applied to each of the plurality of variable elements in accordance with frequency response characteristics of the variable element to remove a portion of a self-interference and/or cross-talk interference signal present in a signal received by the device.