Parameters Acquirement Of New Generation DVB Link Signal And Jamming Adaptability Analysis

The second generation digital video broadcasting(DVB-S2) is the latest standard for various broadband satellite applications, which is high performance, applicable to different businesses and can satisfy various needs of satellite. DVB-S2 has a wide range of use for both civil and military domains. Because DVB-S2 fuses the latest techniques about communication developments in the past 20 years, such cascading BCH and LDPC FEC, 16 APSK and 32 APSK modulations, VCM and ACM, the present link signal processing methods could not be applied for DVB-S2. And the jamming adaptability analysis of DVB-S2 lacks. This dissertation focuses on the key problems of parameters acquirement of DVB-S2 link signal and jamming adaptability analysis, the content of the dissertation is as follows.In chapter 2, the problem of physical layer parameters acquirement of DVB-S2 link signal is investigated. Physical layer parameters are the basis of the whole link signal parameters. Only after the physical layer parameters are obtained, can the data link layer parameters be acquired. The recognition of DVB-S2 link signal method based on physical layer parameters needs fewer computations and is easy to implement. Firstly, the radius constellation is proposed after constituting received DVB-S2 link signal and APSK modulation, make use of GLRT to achieve modulation recognition; Secondly, the recognition of DVB-S2 link signal method based on FEC frame length is proposed, the variable for distinguishing FEC frame length is defined, and the distinguishing method is also proposed. Finally, the SNR estimating model for DVB-S2 is constituted and different estimation formulas for different modulations are derived based on the defining of estimation variable.In chapter 3, the problem of estimating initial time of physical layer header for DVB-S2 is investigated. The initial time of physical layer header which also indicates the initial time of transmitting data and FEC frame is the significant requirement of data link layer parameters. The estimating initial time methods are mainly investigated. Firstly, several important DA methods are present, and then, a non-linear operator based on phase difference is defined, which transform the DA methods to NDA methods, after that, the detection variables for these NDA methods are derived. Finally, a novel NDA initial time estimation method for DVB-S2 which takes full advantage of phase difference of physical layer header is proposed. The proposed method has good estimation performance.In chapter 4, the problem of data link layer parameters acquirement of DVB-S2 link signal is investigated, including the scrambling sequence and FEC parameters. Firstly, equivalent sequence of scrambling sequence is constructed based on the complex scrambling mode, the estimation variable and the estimation method for the equivalent sequence are proposed. The method of calculating estimation threshold is also proposed. The novel method first ever solves the problem of acquiring complex scrambling sequence. Because FEC frame length is large and the encoding process of FEC is complicated, directly acquiring FEC parameters is quite difficult. The indirect idea of acquiring FEC parameters based on code rate is proposed. After deriving the statistical bias of parity check bits of linear block code, the code rate estimation method on GLRT is achieved, which is easy to implement, needs fewer computations, has great ablity of tolerated-error and fine scalability.In chapter 5, the jamming adaptability of DVB-S2 link signal is analysed, including both blanket jamming and deception jamming. The jamming part consists of physical layer header and transmitting data. Firstly, the jamming adaptability of the physical layer header under blanket jamming is studied, jamming type include ?2-BPSK modulation jamming, QPSK modulation jamming and repeater jamming, aimed at different parts of physical layer header. The jamming adaptability analysis considers different use of different part in physical layer header. After that, the jamming adaptability of deception jamming is analysed, including both the physical layer header deception and transmitting data deception, and propose different jamming adaptability evaluation variables.