Abstract: A fluidic die may include a substrate having a flexible region opposite a fluid supply passage within the substrate, a nozzle supported by the substrate proximate the flexible region and a strain sensor on the flexible region of the substrate. The strain sensor may sense strain during flexing of the flexible region to sense fluid back pressure changes.

Abstract: A method and apparatus supply electrical current to a firing actuator of a printhead die across a high side switching transistor in a source follower arrangement and supply a regulated voltage, that is no greater than a concurrent voltage at a drain of the HSS transistor, to a gate of the high side switching transistor.

Abstract: Crack detection circuits for printheads are described. In an example, a crack detection circuit for at least one printhead, includes: crack detectors formed on the at least one printhead; switches selectively coupling the crack detectors on each printhead to a communication bus; and a configuration circuit on each printhead coupled to control inputs of the respective switches, each configuration circuit responsive to a crack detection configuration input to control the respective switches.

Abstract: A method and apparatus supply electrical current to a firing actuator of a printhead die across a high side switching transistor in a source follower arrangement and supply a regulated voltage, that is no greater than a concurrent voltage at a drain of the HSS transistor, to a gate of the high side switching transistor.

Abstract: Embodiments of the present disclosure provide techniques for reducing power consumption by wireless devices through transmission output power control.

Abstract: A method and apparatus test a printed circuit assembly and a print head array with a low-power application to a printed circuit assembly having a power storage component disconnected from a power rail of the printed circuit assembly and test the printed circuit assembly and the print head array with a high-power application to the printed circuit assembly with the printed circuit assembly receiving electrical power from the power storage component.

Abstract: Systems, methods and apparatus a provided for calibrating actual output power of a transmit power sensor for closed loop power control using a quality metric such as error vector magnitude (EVM) to improve power detection accuracy. In aspects, a method for correlating an output of a transmit power sensor with actual output power of a wireless transmitter includes deriving a characteristic correlation between an actual output power of a set of transmit amplifiers and an output power and of a set of corresponding power detection circuits over a range of transmit power levels in a corresponding set of wireless devices; storing the characteristic correlation in a wireless device that is not part of the set from which the characteristic correlation was derived; and sensing an output of a transmit power sensor of the device while the transmitter of the device transmits according to one or more gain settings.

Abstract: Systems, methods and apparatus a provided for calibrating actual output power of a transmit power sensor for closed loop power control using a quality metric such as error vector magnitude (EVM) to improve power detection accuracy. In aspects, a method for correlating an output of a transmit power sensor with actual output power of a wireless transmitter includes deriving a characteristic correlation between an actual output power of a set of transmit amplifiers and an output power and of a set of corresponding power detection circuits over a range of transmit power levels in a corresponding set of wireless devices; storing the characteristic correlation in a wireless device that is not part of the set from which the characteristic correlation was derived; and sensing an output of a transmit power sensor of the device while the transmitter of the device transmits according to one or more gain settings.

Abstract: Embodiments of the present disclosure provide techniques for reducing power consumption by wireless devices through transmission output power control.

Abstract: Systems and methods for wide frequency offset synchronization are provided. A synchronization data sequence is encoded onto a series of OFDM frequency domain bursts as interburst phase differences between training symbols included within the successive bursts. The interburst phase differences may also encode system configuration information. This technique may be used in conjunction with other synchronization techniques to greatly extend the frequency acquisition range achievable with low cost analog components.

Abstract: Systems and methods for optimally receiving differential encoded OFDM signals via multiple antennas. These techniques may exploit spatial diversity without knowledge of channel characteristics. Further systems and methods are provided for exploiting frequency diversity within an OFDM burst where differentially encoded symbols are repeated to assure optimal performance. The output of differential decoding systems may also be used to provide soft decision values for individual bits of multibit symbols to facilitate use of bitwise channel decoding systems.

Abstract: Systems and methods for precisely controlling the amount of redundancy introduced by a turbo encoding process. Bits having predetermined values are introduced into the turbo encoding input stream and then deleted from the turbo encoding output stream. At the receiver end, the bits having predetermined values are reintroduced into the encoded information stream as having been received with a maximum confidence level. Coding rate may be varied by varying the number of bits having predetermined values which are inserted at the encoder input. This scheme permits the amount of redundancy to be varied according to system requirements.

Abstract: Systems and methods for estimating channel response in the presence of interference. Interference and/or noise present on received training symbols is estimated. Based on the measured noise and/or interference, a weighting among training symbols is developed. Channel response is then estimated based on a weighted least squares procedure.

Abstract: Systems and methods for estimating channel response in the presence of interference. Interference and/or noise present on received training symbols is estimated. Based on the measured noise and/or interference, a weighting among training symbols is developed. Channel response is then estimated based on a weighted least squares procedure.

Abstract: Systems and methods for wide frequency offset synchronization are provided. A synchronization data sequence is encoded onto a series of OFDM frequency domain bursts as interburst phase differences between training symbols included within the successive bursts. The interburst phase differences may also encode system configuration information. This technique may be used in conjunction with other synchronization techniques to greatly extend the frequency acquisition range achievable with low cost analog components.

Abstract: Systems and methods for wide offset frequency synchronization in OFDM communications. Frequency domain OFDM bursts include training symbols having known transmitted values in known frequency domain positions. Received values at the known training symbol positions are correlated from burst to burst. The magnitudes are used to establish and correct small integer frequency offsets as measured in frequency domain symbol widths. The phase of the correlation result is used to determine and correct integer frequency offsets that exceed the training tone spacing. Use of the phase to correct large frequency offsets greatly extends the acquisition range required for low cost analog components.

Abstract: Systems and methods for transmitting configuration information in an OFDM communication system. In one embodiment, within a frequency domain burst certain symbols allocated for use in channel estimation also carry system configuration information. The system configuration information may be encoded as phase differences between corresponding training symbols of successive bursts.

Abstract: Systems and methods for efficient multiplexing of multiple access requests from disparate sources within a single OFDM burst. Each of multiple subscriber units employ non-overlapping groups of OFDM frequency domain symbols within a single burst for upstream transmission of their access requests. In one embodiment, the OFDM frequency domain symbols are differentially encoded to eliminate the need for transmission of upstream training information. In an alternative embodiment, the group of frequency domain symbols within the burst employed by any particular subscriber unit are contiguous to one another. Channel training for a give subscriber unit need only be performed over the subband occupied by its group of frequency domain symbols. This greatly reduces the number of training symbols required for reception.

Abstract: Systems and methods for converting a baseband OFDM signal to an IF signal while minimizing lengthening of the impulse response duration experienced by the OFDM signal. A conversion technique according to the present invention provides sufficient filtering to limit the effects of spurious frequency domain components caused by transitions between successive OFDM bursts. In one embodiment, the filtering is provided by a combination of a finite impulse response (FIR) filter having non-linear phase characteristics and a cyclic convolution filter. Conversion from the frequency domain into the time domain, upsampling, and cyclic filtering may be combined into one operation.

Abstract: Systems and methods for optimally receiving differential encoded OFDM signals via multiple antennas. These techniques may exploit spatial diversity without knowledge of channel characteristics. Further systems and methods are provided for exploiting frequency diversity within an OFDM burst where differentially encoded symbols are repeated to assure optimal performance. The output of differential decoding systems may also be used to provide soft decision values for individual bits of multibit symbols to facilitate use of bitwise channel decoding systems.