In this paper, we address the rate control, the Medium Access Control (MAC) and the routing problem for cooperative Vehicular Ad-Hoc Network (VANET) in the framework of cross-layer design. At first, we introduce the cooperative communication conception to VANET, and propose an opportunistic cooperation strategy to improve the system performance. And then, we develop a cross-layer solution which consists of the link capacity detection with adjusting persistence probability at the MAC Layer, the flow rate control with the maximal utility at the Transport Layer and the routing design at the Network Layer. This proposal is designed in distributed manner in order to support a simple and efficient implementation for VANET. Furthermore, some practical issues, such as fairness and network cost, are presented for implementing the proposed solution and improving the system performance. Simulation results show that the proposed opportunistic cooperation strategy combined with joint control algorithm achieves the desired performance over VANET.

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In high-frequency (HF) hybrid sky-surface wave radar, the first-order sea clutter broadening is very severely under the influence of ionosphere and bistatic angle, which affects the detection of ship target. In this study, a cascaded method for ionospheric decontamination and sea clutter suppression to enable detection of ship target is presented. Firstly, the radar configuration, sea clutter broadening characteristics, and model are introduced based on the newly-developed integrated HF sky-surface wave experimental system. In the cascaded processing method, the time-frequency analysis method based on S 2-method is used to correct the ionospheric phase contamination with large amplitude. Then, a novel forward-backward linear prediction algorithm is proposed to suppress the broadening bistatic sea clutter caused by bistatic angle, which is based on the distribution characteristics and the multidimensional feature of first-order sea clutter. Finally, the proposed method is examined by measured data. Experimental results indicate that the proposed method can well suppress the broadening sea clutter and improve the ship target detection performance.

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