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In this letter, we establish physical-layer security based on frequency diverse array (FDA) together with directional modulation (DM) for decode and forward (DF) relaying simultaneous wireless information and power transfer (SWIPT) system. The analytical expressions of the ergodic system secrecy capacity under the time switching (TS) protocol are derived. Moreover, the impacts of system parameters on secure performance are analysed. Numerical results reveal that the proposed method achieves better security performance than conventional PA solutions, especially in the range dimension. [ABSTRACT FROM AUTHOR]

The waveforms used in Multiple-Input Multiple-Output (MIMO) Synthetic Aperture Radar (SAR) should have a large time-bandwidth product and good ambiguity function performance. A scheme to design multiple orthogonal MIMO SAR Orthogonal Frequency Division Multiplexing (OFDM) chirp waveforms by combinational sparse matrix and correlation optimization is proposed. First, the problem of MIMO SAR waveform design amounts to the associated design of hopping frequency and amplitudes. Then a iterative exhaustive search algorithm is adopted to optimally design the code matrix with the constraints minimizing the block correlation coefficient of sparse matrix and the sum of cross-correlation peaks. And the amplitudes matrix are adaptively designed by minimizing the cross-correlation peaks with the genetic algorithm. Additionally, the impacts of waveform number, hopping frequency interval and selectable frequency index are also analyzed. The simulation results verify the proposed scheme can design multiple orthogonal large time-bandwidth product OFDM chirp waveforms with low cross-correlation peak and sidelobes and it improves ambiguity performance.

Introduction: This study aimed to investigate the presentations and survival outcomes of the distant metastatic non‐small cell lung cancer (NSCLC) without lymph node involvement to obtain a clearer picture of this special subgroup of metastatic NSCLC. Method: A least absolute shrinkage and selection operator (LASSO) penalized Cox regression analysis was used to select the prognostic variables. A nomogram and corresponding risk‐classifying systems were constructed. The C‐index and calibration curves were used to evaluate the performance of the model. Overall survival (OS) curves were plotted using the Kaplan–Meier method, and the log‐rank test was used to compare OS differences between groups. Propensity score matching (PSM) was performed to reduce bias. Result: A total of 12 610 NSCLC patients with M1 category (N0 group: 3045 cases; N1‐3 group: 9565 cases) were included. Regarding the N0 group, multivariate analysis demonstrated that age, sex, race, surgery, grade, tumor size, and M category were independent prognostic factors. A nomogram and corresponding risk‐classifying systems were formulated. Favorable validation results were obtained from the C‐index, calibration curves, and survival comparisons. Survival curves demonstrated that N0 NSCLC patients had better survival than N1‐3 NSCLC patients both before and after PSM. Furthermore, the survival of resected N0M1 patients was superior to that of those without surgery. Conclusion: In this study, a prognostic nomogram and risk‐classifying systems designed for the T1‐4N0M1 NSCLC patients showed acceptable performance. Primary lung tumor resection might be a feasible treatment for this population subset. Additionally, we proposed that lymph node stage might have a place in the forthcoming tumor‐node‐metastasis (TNM) staging proposal for NSCLC patients with M1 category. [ABSTRACT FROM AUTHOR]

Recently, sparse planar arrays have been developed to improve the 2-D direction-of-arrival (DOA) estimation performance by their superiorities in the degree of freedom (DOF), array aperture, and mutual coupling over uniform planar arrays. In this article, we devise a new sparse planar array, termed symmetric displaced coprime planar array (SDCPA), for estimating the 2-D DOAs. The SDCPA configuration consists of three sparse uniform rectangular arrays (URAs) with a certain horizontal and vertical displacement, implying that there are two bilaterally SDCPAs with one shared subarray. Under any number of sensors, the sensor positions of an SDCPA can be expressed in a closed form. We also derive the optimal displacement factors to achieve the maximum number of consecutive coarray lags, which can be analytically calculated. Compared with the conventional CPAs, the SDCPA configuration possesses a higher number of uniform DOFs and fewer mutual coupling effects. Numerical results demonstrate its superiority over several existing sparse planar arrays. [ABSTRACT FROM AUTHOR]