Decomposition of a stereo signal into the primary and ambient components is a key step to the stereo upmix and it is often based on the principal component analysis (PCA). However, major shortcoming of the PCA-based method is that accuracy of the decomposed components is dependent on both the primary-to-ambient power ratio (PAR) and the panning angle. Previously, a modified PCA was suggested to solve the PAR-dependent problem. However, its performance is still dependent on the panning angle of the primary signal. In this paper, we proposed a new PCA-based primary-ambient decomposition algorithm whose performance is not affected by the PAR as well as the panning angle. The proposed algorithm finds scale factors based on a criterion that is set to preserve the powers of the mixed components, so that the original primary and ambient powers are correctly retrieved. Simulation results are presented to show the effectiveness of the proposed algorithm.
We provide techniques to generate and characterize precision wideband millimeter-wave modulated signals. We use predistortion to obtain a significant improvement in signal quality and an associated reduction in the error vector magnitude (EVM) of the signals generated by an arbitrary-waveform-generator-based source. We adapt a recently developed microwave uncertainty framework to the problem and use it to estimate the uncertainties in the modulated-signal measurements. Models of uncertainties related to all calibration and measurement procedures within the traceability path are included in a sensitivity analysis and Monte Carlo simulations that maintain correlations between time-and frequency-domain errors. We demonstrate EVM values of approximately 1.6% 0.5% for a 1-GSymbol/s 64-state quadrature-amplitude-modulated signal at 44 GHz.Index Terms-Digitally modulated signal, error vector magnitude (EVM), measurement uncertainty, microwave measurement, millimeter-wave wireless communications, oscilloscope, wireless system.
Background:We investigated the incidence and location of heterotopic ossification (HO) following hip arthroscopy. Methods: This retrospective study enrolled 327 patients who underwent hip arthroscopy from January 2010 to December 2015. From this cohort, we extracted an HO group with simple radiographs or three-dimensional computed tomography (3D CT). Findings consistent with HO were classified according to the Brooker classification aided with 3D CT for the location of HO. The indication for revision arthroscopic excision of HO was painful,
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