37,081 research outputs found

    A low-complexity feed-forward I/Q imbalance compensation algorithm

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    This paper presents a low-complexity adaptive feed- forward I/Q imbalance compensation algorithm. The feed-forward so- lution has guaranteed stability. Due to its blind nature the algorithm is easily incorporated into an existing receiver design. The algorithm uses three estimators to obtain the necessary parameters for the I/Q imbal- ance compensation structure. The algorithm complexity is low due to 1-bit quantization in the estimators. Simulations show that the compen- sation algorithm is able to attain an image-rejection ratio (IRR) of up to 65 [dB] under various imbalance conditions

    Development and stability of gyrotactic plumes in bioconvection

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    Using the continuum model of Pedley, Hill and Kessler (1988) for bioconvection in a suspension of swimming, gyrotactic micro-organisms, we investigate the existence and stability of a two-dimensional plume in tall, narrow chambers with stress-free sidewalls. The system is governed by the Navier–Stokes equations for an incompressible fluid coupled with a micro-organism conservation equation. These equations are solved numerically using a conservative finite-difference scheme. In sufficiently deep chambers, the plume is always unstable to both varicose and meandering modes. A linear stability analysis for an infinitely long plume predicts the growth rates of these instabilities, explains the mechanisms, and is in good agreement with the numerical results
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