Abstract: Circuits and methods for reducing power consumption in a half-duplex transceiver are disclosed. In an embodiment, a power management circuit of half-duplex transceiver includes direct current to direct current (DC-DC) converter and snooze mode controller. The DC-DC converter includes switching circuit and driver circuit to drive the switching circuit. The DC-DC converter provides power supply to at least one element of a transmitter sub-system of the half-duplex transceiver, and operates in snooze control modes. The snooze mode controller is coupled to the DC-DC converter and configured to generate a control signal based on at least one transceiver operating input, where the control signal causes the DC-DC converter to operate in one of the snooze control modes, the snooze control modes corresponding to snooze duty cycles and where in each snooze control mode, the switching circuit and the driver circuit remain in an OFF-state based on a respective snooze duty cycle.

Abstract: A radar system is provided that includes a receive channel configured to receive a reflected signal and to generate a first digital intermediate frequency (IF) signal based on the reflected signal, a reference receive channel configured to receive a reflected signal and to generate a second digital IF signal based on the reflected signal, and digital mismatch compensation circuitry coupled to receive the first digital IF signal and the second digital IF signal, the digital mismatch compensation circuitry configured to process the first digital IF signal and the second digital IF signal to compensate for mismatches between the receive channel and the reference receive channel.

Abstract: A weather band receiver, which may be part of an FM receiver, is disclosed. FSK-encoded data units in an alert packet transmission are detected using a quadrature matched filter circuit. At least one FSK-encoded data unit is captured from the alert packet transmission. Soft quantized bits are extracted from the FSK-encoded data units. The soft quantized bits are saved to memory and used to recover an alert message. Soft quantized bits from two or more FSK-encoded data units may be combined before recovering the alert message.

Abstract: Suppression of interference across transceivers integrated on a single semiconductor chip. An example of a method of reducing noise in a transceiver includes introducing an adjustable time delay into a signal between a first section of a signal path into which noise may be introduced and a second section of the signal path into which noise may be introduced. The method also includes selectively adjusting the time delay and signal polarity to improve a signal-to-noise metric of the transceiver. An example of the transceiver includes a transmitter and a receiver. The transceiver also includes an adjustable time delay between a first section of a transceiver signal path into which noise may be introduced and a second section of the transceiver signal path into which noise may be introduced and circuitry for reducing noise by adjusting a value of the time delay.

Abstract: Example embodiments of systems and methods of direct oversampled low PAR pulse shaping encapsulating DSSS spreading are disclosed herein. Pulse-shaping of a DSSS spread data symbol stream results in a small number of waveform patterns to choose from for any data-symbol window. Low complexity programmable look-up table (LUT) based direct pulse shaping may be implemented, while only needing to compute a negation function. The chosen pulse shape may generate a low PAR for the baseband signal, allowing for a reduction in the saturation power of the power amplifier, thereby reducing the overall transmitter power consumption.

Abstract: A frequency modulated continuous wave (FMCW) radar system is provided that includes a receiver configured to generate a digital intermediate frequency (IF) signal, and an interference monitoring component coupled to the receiver to receive the digital IF signal, in which the interference monitoring component is configured to monitor at least one sub-band in the digital IF signal for interference, in which the at least one sub-band does not include a radar signal.

Abstract: According to an aspect of the present disclosure, the relative attitude between an inertial measurement unit (IMU), present on a mobile device, and the frame of reference of the vehicle carrying mobile device is estimated. The estimated relative attitude is used to translate the IMU measurement to the vehicle frame of reference to determine the velocity and position of the vehicle. As a result, the vehicle position and velocity are determined accurately in the event of undocking and re-docking of the mobile device from a docking system in the vehicle. The relative attitude is estimated in terms of pitch, roll, and yaw angles.

Abstract: Circuits and methods for reducing power consumption in a half-duplex transceiver are disclosed. In an embodiment, a power management circuit of half-duplex transceiver includes direct current to direct current (DC-DC) converter and snooze mode controller. The DC-DC converter includes switching circuit and driver circuit to drive the switching circuit. The DC-DC converter provides power supply to at least one element of a transmitter sub-system of the half-duplex transceiver, and operates in snooze control modes. The snooze mode controller is coupled to the DC-DC converter and configured to generate a control signal based on at least one transceiver operating input, where the control signal causes the DC-DC converter to operate in one of the snooze control modes, the snooze control modes corresponding to snooze duty cycles and where in each snooze control mode, the switching circuit and the driver circuit remain in an OFF-state based on a respective snooze duty cycle.

Abstract: Digital values representing an audio signal are formed in a FM transmitter. The deviation of the amplitude of the audio signal as represented by the digital values, from a reference amplitude level, is measured. The audio signal is filtered based on the deviation measured by processing the digital values, with the filtering designed to filter different frequency components of the audio signal with different respective magnitudes. Another set of digital values representing the filtered audio signal is generated, and used to frequency modulate a carrier signal to generate a FM signal. Over-modulation of the FM signal is thereby controlled.

Abstract: A weather band receiver, which may be part of an FM receiver, is disclosed. FSK-encoded data units in an alert packet transmission are detected using a quadrature matched filter circuit. At least one FSK-encoded data unit is captured from the alert packet transmission. Soft quantized bits are extracted from the FSK-encoded data units. The soft quantized bits are saved to memory and used to recover an alert message. Soft quantized bits from two or more FSK-encoded data units may be combined before recovering the alert message.

Abstract: Several circuits and methods implemented to perform signal quality estimation and control are disclosed. In an embodiment, a method of signal quality estimation includes generating a demodulated signal associated with a radio signal. Information associated with a quality of the demodulated signal is accessed. Further, a value of radio frequency signal-to-noise ratio (RF-SNR) for the radio signal based on the information is estimated. Estimating the value of RF-SNR facilitates in signal quality estimation of the radio signal and control of the demodulated signal.

Abstract: In the present disclosure, an error in the velocity and position computed from a three dimensional IMU measurement is reduced confined by computing an auxiliary speed in a drive direction of a vehicle from an angular velocity measurement and a lateral acceleration measurement. The auxiliary speed is then compared with the speed computed from the acceleration measurement. The auxiliary speed is provided as the speed of the vehicle mounted with the IMU when the absolute difference between the auxiliary speed and the speed computed from the acceleration measurement in the drive direction is above a threshold. The auxiliary speed is computed when the vehicle is detected to be in a curved motion. According to another aspect of the present disclosure, the bias errors are determined when the vehicle is in a steady state, at rest or in a straight line motion. The bias errors are used to obtain the accurate auxiliary measurement.

Abstract: An electronic circuit (100) for use in a wireless receiver (1720). The circuit (100) includes an audio demodulator (15), an audio envelope portion (35) operable to deliver an audio envelope signal, a high pass filter (38) coupled between the audio demodulator (15) and the audio envelope portion (35), a volume control (25) fed by the audio demodulator (15) and operable to provide a controllable audio signal output, and a controller (45) responsive to the audio envelope portion (35) to provide an attenuation control to the volume control (25). Other circuits, receivers, processes of operation, processes of manufacture, and processes of testing are disclosed.

Abstract: According to an aspect of the present disclosure, the relative attitude between an inertial measurement unit (IMU), present on a mobile device, and the frame of reference of the vehicle carrying mobile device is estimated. The estimated relative attitude is used to translate the IMU measurement to the vehicle frame of reference to determine the velocity and position of the vehicle. As a result, the vehicle position and velocity are determined accurately in the event of undocking and re-docking of the mobile device from a docking system in the vehicle. The relative attitude is estimated in terms of pitch, roll, and yaw angles.

Abstract: In the present disclosure, an error in the velocity and position computed from a three dimensional IMU measurement is reduced confined by computing an auxiliary speed in a drive direction of a vehicle from an angular velocity measurement and a lateral acceleration measurement. The auxiliary speed is then compared with the speed computed from the acceleration measurement. The auxiliary speed is provided as the speed of the vehicle mounted with the IMU when the absolute difference between the auxiliary speed and the speed computed from the acceleration measurement in the drive direction is above a threshold. The auxiliary speed is computed when the vehicle is detected to be in a curved motion. According to another aspect of the present disclosure, the bias errors are determined when the vehicle is in a steady state, at rest or in a straight line motion. The bias errors are used to obtain the accurate auxiliary measurement.

Abstract: Several circuits and methods implemented to perform signal quality estimation and control are disclosed. In an embodiment, a method of signal quality estimation includes generating a demodulated signal associated with a radio signal. Information associated with a quality of the demodulated signal is accessed. Further, a value of radio frequency signal-to-noise ratio (RF-SNR) for the radio signal based on the information is estimated. Estimating the value of RF-SNR facilitates in signal quality estimation of the radio signal and control of the demodulated signal.

Abstract: A vehicle navigation system includes a GNSS position engine (GPE) that uses GNSS satellite measurements to compute a first position and velocity of a vehicle and a first quality metric associated with the position and velocity. The system also includes a dead reckoning engine (DRE) that operates parallel with the GPE that computes a second position and velocity and a second quality metric associated with the dead reckoning. The GPE is configured to use the second position and velocity to detect a set of outliers in an incoming GNSS measurement; use the second position and velocity as an initial estimate of its position and velocity for a particular time instant, which is then refined by GNSS measurements received at that particular time instant; and to replace the first position and velocity with the second position and velocity.

Abstract: Suppression of interference across transceivers integrated on a single semiconductor chip. An example of a method of reducing noise in a transceiver includes introducing an adjustable time delay into a signal between a first section of a signal path into which noise may be introduced and a second section of the signal path into which noise may be introduced. The method also includes selectively adjusting the time delay and signal polarity to improve a signal-to-noise metric of the transceiver. An example of the transceiver includes a transmitter and a receiver. The transceiver also includes an adjustable time delay between a first section of a transceiver signal path into which noise may be introduced and a second section of the transceiver signal path into which noise may be introduced and circuitry for reducing noise by adjusting a value of the time delay.

Abstract: Frequency synthesizer with immunity from oscillator pulling. The frequency synthesizer for generating an output frequency includes an oscillator that is capable of generating a first frequency. The frequency synthesizer also includes an output divider coupled to the oscillator. The output divider is configurable to allow the oscillator to generate a second frequency to prevent degradation in phase noise due to an interference to the first frequency of the oscillator, and to generate the output frequency from the second frequency.

Abstract: An electronic circuit (100) for use in a wireless receiver (1720). The circuit (100) includes an audio demodulator (15), an audio envelope portion (35) operable to deliver an audio envelope signal, a high pass filter (38) coupled between the audio demodulator (15) and the audio envelope portion (35), a volume control (25) fed by the audio demodulator (15) and operable to provide a controllable audio signal output, and a controller (45) responsive to the audio envelope portion (35) to provide an attenuation control to the volume control (25). Other circuits, receivers, processes of operation, processes of manufacture, and processes of testing are disclosed.