National Instruments Corporation

Other

Mohamad A Zeidan

Christopher J Behnke

Syed Jaffar Shah

Thieab Ibrahim Aldossary

Dynamic characterization of complex high-order nonlinearity in transmitter (TX) and receiver (RX) signal chains of transceiver systems can be efficiently and accurately performed. A loopback connection may be used to facilitate self-characterization. Appropriate RX and TX configuration settings may be developed to facilitate de-coupling of individual RX and TX nonlinearities from measured cascade nonlinearity. The system's high-order response to a two-tone signal generation may be measured, and complex mathematical analysis may be performed to identify and isolate passband nonlinear components to extract a high-order memory-less model for the system. The extracted system model may be used in the corrective and non-iterative pre-distortion of generated signals and in the post-distortion of received signals to improve linearity performance of the transceiver. The memory-less model and the analytical system are effective in improving performance of class-A-amplifier-based signal chains that are common in test and measurement systems and channel emulation systems.

Linearization of radio frequency transceivers and test systems through dynamic extraction of complex nonlinear models thereof

A tactile communication apparatus that includes a signal receiver configured to decode data received via a wireless signal a plurality of electro tactile pads on one side, each pad configured to respectively activate and deactivate to form a plurality of pad combinations based on a plurality of activation signals, and a communication processor configured to generate the plurality of electro tactile pad activation signals based on the received data so as to convey the data to a user through the plurality of pad combinations of the tactile communication apparatus.

Electro tactile communication apparatus, method, and computer program product

A mechanism for measuring noise densities below the noise floor of a measuring instrument. The measuring instrument may first acquire a fully-averaged reference spectral noise density trace and estimate corresponding reference statistical parameters. Based on the reference statistical parameters, the measuring instrument may construct a reference spectral noise density distribution. The measuring instrument may also acquire a fully-averaged sum spectral noise density trace and estimate corresponding sum statistical parameters. Based on the sum statistical parameters, the measuring instrument may construct a sum spectral noise density distribution. The measuring instrument may extract a spectral noise density distribution from the reference and sum distributions. The measuring instrument may also determine a confidence interval based on a desired confidence level. The measuring instrument may then determine a desired spectral noise density measurement based on an extracted mean of the spectral noise density and the computed confidence interval.

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Austin, TX, United States of America

Mohamad A Zeidan