Abstract: Radio frequency (RF) communication systems with coexistence management are provided herein. In certain embodiments, a mobile device includes a first antenna, a first front end system that receives an RF receive signal from the first antenna, a first transceiver coupled to the first front end system, a second antenna, a second front end system that provides an RF transmit signal to the second antenna, and a second transceiver coupled to the second front end system. The second front end system observes the RF transmit signal to generate an RF observation signal, which is downconverted and processed by the second transceiver to generate digital observation data that is provided to the first transceiver. The first transceiver downconverts the RF receive signal to baseband, and compensates the baseband receive signal for an amount of RF signal leakage indicated by the digital observation data.

Abstract: Radio frequency (RF) communication systems with coexistence management are provided herein. In certain embodiments, a method of coexistence management in a mobile device includes processing an RF receive signal to generate a digital baseband receive signal using a receive channel of a first transceiver, processing a first RF observation signal to generate a first digital observation signal using a first observation channel of the first transceiver, generating spectral regrowth observation data based on processing process the first digital observation signal using a first spectral regrowth baseband sampling circuit of the first transceiver, and compensating the digital baseband receive signal for RF signal leakage based on the spectral regrowth observation data and on direct transmit leakage observation data using a discrete time cancellation circuit of the first transceiver.

Abstract: Radio frequency front-end systems with filter reuse. In certain embodiments, a front-end system includes a filter, a low noise amplifier (LNA), and a switch interposed between the filter and an input to the LNA. In a first state of the switch, the filter serves to filter a radio frequency signal that is amplified by the LNA. The front-end system further includes a power amplifier that is coupled to the switch. Additionally, in a second state of the switch, the filter serves to filter an amplified radio frequency transmit signal provided by the power amplifier. Accordingly, a filter along a receive path of the front-end system is reused for transmit.

Abstract: The radio frequency front-end systems herein include modules having bandwidth controllable components, such as amplifier and filters. By implementing the modules with bandwidth control, the same module can be used for operation of multiple frequency bands including a first frequency band and a second frequency band. Thus, when implementing features such as carrier aggregation, multiple-input multiple-output (MIMO), and/or sounding resource signaling (SRS) for supporting the multiple frequency bands, the total number of modules used can be reduced and/or additional feature support can be provided compared to an implementation in which each module supports a single frequency band.

Abstract: Radio frequency (RF) communication systems with coexistence management are provided herein. In certain embodiments, a method of coexistence management in a mobile device includes providing an RF receive signal from a first front end system to a first transceiver, generating an RF transmit signal and an RF observation signal using a second front end system, the RF observation signal generated based on observing the RF transmit signal, generating digital observation data based on the RF observation signal using a second transceiver, downconverting the RF receive signal to generate a baseband receive signal using the first transceiver, and compensating the baseband receive signal for RF signal leakage based on the digital observation data using the first transceiver.

Abstract: Radio frequency (RF) communication systems with coexistence management are provided herein. In certain embodiments, a method of coexistence management in a mobile device includes providing an RF receive signal from a first front end system to a first transceiver, generating an RF transmit signal and an RF observation signal using a second front end system, the RF observation signal generated based on observing the RF transmit signal, generating digital observation data based on the RF observation signal using a second transceiver, downconverting the RF receive signal to generate a baseband receive signal using the first transceiver, and compensating the baseband receive signal for RF signal leakage based on the digital observation data using the first transceiver.

Abstract: Radio frequency (RF) communication systems with coexistence management are provided herein. In certain embodiments, a method of coexistence management in a mobile device includes processing an RF receive signal to generate a digital baseband receive signal using a receive channel of a first transceiver, processing a first RF observation signal to generate a first digital observation signal using a first observation channel of the first transceiver, generating spectral regrowth observation data based on processing process the first digital observation signal using a first spectral regrowth baseband sampling circuit of the first transceiver, and compensating the digital baseband receive signal for RF signal leakage based on the spectral regrowth observation data and on direct transmit leakage observation data using a discrete time cancellation circuit of the first transceiver.

Abstract: Antenna-plexers for interference cancellation are provided herein. In certain embodiments, a wireless device includes an antenna, an antenna-plexer coupled to the antenna and configured to generate a feedback signal, a transmitter configured to transmit a transmit signal to the antenna by way of the antenna-plexer, a receiver configured to process a receive signal, and a feedback receiver configured to process the feedback signal from the antenna-plexer to provide compensation to the receive signal.

Abstract: RF communication systems with interference cancellation for coexistence are provided herein. In certain embodiments, an RF communication system includes a transmitter that transmits a transmit signal through a first front end circuit, a receiver that processes a receive signal from a second front end circuit, and a feedback receiver that processes a feedback signal from the first front end circuit to generate a digital interference cancellation signal that compensates the receiver for interference arising from the transmitter.

Abstract: Radio frequency (RF) communication systems with coexistence management are provided herein. In certain embodiments, a mobile device includes a first antenna, a first front end system that receives an RF receive signal from the first antenna, a first transceiver coupled to the first front end system, a second antenna, a second front end system that provides an RF transmit signal to the second antenna, and a second transceiver coupled to the second front end system. The second front end system observes the RF transmit signal to generate an RF observation signal, which is downconverted and processed by the second transceiver to generate digital observation data that is provided to the first transceiver. The first transceiver downconverts the RF receive signal to baseband, and compensates the baseband receive signal for an amount of RF signal leakage indicated by the digital observation data.

Abstract: Radio frequency (RF) communication systems with coexistence management are provided herein. In certain embodiments, a method of coexistence management in a mobile device includes processing an RF receive signal to generate a digital baseband receive signal using a receive channel of a first transceiver, processing a first RF observation signal to generate a first digital observation signal using a first observation channel of the first transceiver, generating spectral regrowth observation data based on processing process the first digital observation signal using a first spectral regrowth baseband sampling circuit of the first transceiver, and compensating the digital baseband receive signal for RF signal leakage based on the spectral regrowth observation data and on direct transmit leakage observation data using a discrete time cancellation circuit of the first transceiver.

Abstract: Radio frequency (RF) communication systems with coexistence management are provided herein. In certain embodiments, a method of coexistence management in a mobile device includes providing an RF receive signal from a first front end system to a first transceiver, generating an RF transmit signal and an RF observation signal using a second front end system, the RF observation signal generated based on observing the RF transmit signal, generating digital observation data based on the RF observation signal using a second transceiver, downconverting the RF receive signal to generate a baseband receive signal using the first transceiver, and compensating the baseband receive signal for RF signal leakage based on the digital observation data using the first transceiver.

Abstract: Radio frequency (RF) communication systems with coexistence management are provided herein. In certain embodiments, a mobile device includes a first antenna, a first front end system that receives an RF receive signal from the first antenna, a first transceiver coupled to the first front end system, a second antenna, a second front end system that provides an RF transmit signal to the second antenna, and a second transceiver coupled to the second front end system. The second front end system observes the RF transmit signal to generate an RF observation signal, which is downconverted and processed by the second transceiver to generate digital observation data that is provided to the first transceiver. The first transceiver downconverts the RF receive signal to baseband, and compensates the baseband receive signal for an amount of RF signal leakage indicated by the digital observation data.

Abstract: Radio frequency (RF) communication systems with interference cancellation for coexistence are provided herein. In certain embodiments, an RF communication system includes a transmitter that transmits a transmit signal through a first front end system, a receiver that processes a receive signal from a second front end system, and an interference cancellation circuit that generates an interference cancellation signal that compensates the receiver for interference arising from the transmitter. The interference cancellation circuit includes a filter for filtering the transmit signal, a controllable phase circuit for adjusting a phase of the interference cancellation signal, and a controllable gain circuit for adjusting a gain of the interference cancellation signal.

Abstract: Radio frequency (RF) communication systems with coexistence management are provided herein. In certain embodiments, a mobile device includes a first antenna, a first front end system that receives an RF receive signal from the first antenna, a first transceiver coupled to the first front end system, a second antenna, a second front end system that provides an RF transmit signal to the second antenna, and a second transceiver coupled to the second front end system. The first front end system generates a first observation signal by observing the RF receive signal, and the second front end system generates a second observation signal by observing the RF transmit signal. The first transceiver also downconverts the RF receive signal to baseband, and uses the first observation signal and the second observation signal to compensate the baseband receive signal for RF signal leakage.

Abstract: Radio frequency (RF) communication systems with coexistence management are provided herein. In certain embodiments, a method of coexistence management in a mobile device includes providing an RF receive signal from a first front end system to a first transceiver, generating an RF transmit signal and an RF observation signal using a second front end system, the RF observation signal generated based on observing the RF transmit signal, generating digital observation data based on the RF observation signal using a second transceiver, downconverting the RF receive signal to generate a baseband receive signal using the first transceiver, and compensating the baseband receive signal for RF signal leakage based on the digital observation data using the first transceiver.

Abstract: Radio frequency (RF) communication systems with coexistence management are provided herein. In certain embodiments, a method of coexistence management in a mobile device includes processing an RF receive signal to generate a digital baseband receive signal using a receive channel of a first transceiver, processing a first RF observation signal to generate a first digital observation signal using a first observation channel of the first transceiver, generating spectral regrowth observation data based on processing process the first digital observation signal using a first spectral regrowth baseband sampling circuit of the first transceiver, and compensating the digital baseband receive signal for RF signal leakage based on the spectral regrowth observation data and on direct transmit leakage observation data using a discrete time cancellation circuit of the first transceiver.

Abstract: Radio frequency (RF) communication systems with coexistence management are provided herein. In certain embodiments, a mobile device includes a first antenna, a first front end system that receives an RF receive signal from the first antenna, a first transceiver coupled to the first front end system, a second antenna, a second front end system that provides an RF transmit signal to the second antenna, and a second transceiver coupled to the second front end system. The second front end system observes the RF transmit signal to generate an RF observation signal, which is downconverted and processed by the second transceiver to generate digital observation data that is provided to the first transceiver. The first transceiver downconverts the RF receive signal to baseband, and compensates the baseband receive signal for an amount of RF signal leakage indicated by the digital observation data.

Abstract: A cloud security service receives an electronic message sent by a purported sending user to a receiving user. The cloud security service retrieves a user model and a user identity associated with the purported sending user, the user identity including a set of feature values describing messages from the purported sending user. The cloud security service applies the user model to the received electronic message to identify a set of feature values describing the electronic message. The cloud security service compares the set of feature values describing the electronic message to the set of feature values describing messages from the purported sending user included in the user identity. The cloud security service determines, based on the comparison, whether the received electronic message was sent by the purported sending user. The cloud security service performs a security action based on the determination.

Abstract: A cloud security service provides network security. The cloud security service receives, via a computer network, an electronic message sent by a sending user of an enterprise to a receiving user. The cloud security service analyzes the electronic message using a machine-learned user model describing the sending user's electronic messages, the user model generated based at least in part on previous electronic messages sent by the sending user. The cloud security service determines, based on the analysis, that the electronic message violates a security policy of the enterprise. The cloud security service performs a security action based on the determination that the electronic message violates the security policy.