卫星回传链路CPM信号符号速率估计
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摘要
解决了DVB-RCS2标准定义的连续相位调制(CPM)信号符号速率估计问题。该信号存在于卫星回传链路上,且以TDMA突发模式传输。标准规定了CPM的调制指数、调制阶数和频率成型脉冲等参数,但未对符号速率进行规定。短突发长度、低信噪比环境下实现CPM符号速率估计是信号解调的关键。文中提出了一种基于改进后的广义检测后积分(GPDI)匹配准则的符号速率估计方法。算法首先通过对信号带宽的粗估,获得信号符号速率范围;然后利用不同过采样倍数下的独特码调制波形作为特征,采用改进后的GPDI匹配准则实现信号符号速率估计。通过该方法可在单个突发帧下实现符号速率估计。仿真实验表明,该算法对频偏具有较好的鲁棒性和优异的抗噪声性能。
This paper tackles the symbol rate estimation problem of Continuous Phase Modulation( CPM) that is defined by DVB-RCS2 standard. The signal exists in satellite return link,and transmits in TDMA burst mode. The standard specifies the modulation index,modulation order and frequency shaping pulse of CPM except symbol rate. Symbol rate estimation is crucial for CPM demodulation under short burst length and low signal-to-noise ratio condition. The paper presents a method of symbol rate estimation based on improved Generalized Post Detection Integration( GPDI) match strategy. In the first stage,coarse estimation of bandwidth is used to extract the range of symbol rate. The symbol rate estimation is achieved based on the improved GPDI match strategy using the modulated unique word of different oversampling factor. The symbol rate can be estimated in one single burst frame. Simulation results show that the algorithm is robust with carrier frequency. It is able to provide good performance under low signal-to-noise ratio conditions.
This paper tackles the symbol rate estimation problem of Continuous Phase Modulation( CPM) that is defined by DVB-RCS2 standard. The signal exists in satellite return link,and transmits in TDMA burst mode. The standard specifies the modulation index,modulation order and frequency shaping pulse of CPM except symbol rate. Symbol rate estimation is crucial for CPM demodulation under short burst length and low signal-to-noise ratio condition. The paper presents a method of symbol rate estimation based on improved Generalized Post Detection Integration( GPDI) match strategy. In the first stage,coarse estimation of bandwidth is used to extract the range of symbol rate. The symbol rate estimation is achieved based on the improved GPDI match strategy using the modulated unique word of different oversampling factor. The symbol rate can be estimated in one single burst frame. Simulation results show that the algorithm is robust with carrier frequency. It is able to provide good performance under low signal-to-noise ratio conditions.
引文
[1]ETSI TR 101 790 V1.2.1.Digital Video Broadcasting(DVB);Interaction channel for Satellite Distribution Systems;Guidelines for the use of EN 301 790[S].2003.
[2]ETSI EN 301 545-2 V1.1.1.Digital Video Broadcasting(DVB);Second Generation DVB Interactive Satellite Systems(DVBRCS2);Part 2:Lower Layers for Satellite standard[S].2011.
[3]周家喜.非协作通信中连续相位调制信号盲解调关键技术研究[D].合肥:中国科学技术大学,2009.
[4]Bianchi P,Loubaton P,Sirven F.On the blind estimation of the parameters of continuous phase modulated signals[J].IEEE Trans.Communications,2005,23(5):944-962.
[5]王宁,彭华,崔伟亮.一种非数据辅助的连续相位调制信号符号速率估计算法[J].信号处理,2010,26(12):1864-1869.
[6]隋丹,葛临东.一种基于DWT-CWT的CPFSK信号盲符号速率估计算法[J].系统仿真学报,2008,20(16):4269-4272.
[7]Corazza G E,Salmi P,Vanelli-Coralli A,et al.Differential and non-Coherent post detection integration techniques for the return link of satellite W-CDMA systems[C]//Proceeding of IEEE Personal Indoor and Mobile Radio Communications.2002:300-304.
[8]Corazza G E,Pedone R.Generalized and average post detection integration methods for code acquisition[C]//Proceeding of the IEEE Int.Symposium on Spread Spectrum Techniques and Applications.2004:207-211.
[9]Cioni S,Corazza G E.Unified Frame Acquisition and Symbol Timing Estimation for CPM Return Link Transmission[C]//IEEE Global Telecommunications Conference.2007:1519-1523.
[10]王勇军,彭华.卫星回传链路CPM信号调制识别研究[J].信息工程大学学报,2013,14(3):347-352.
[2]ETSI EN 301 545-2 V1.1.1.Digital Video Broadcasting(DVB);Second Generation DVB Interactive Satellite Systems(DVBRCS2);Part 2:Lower Layers for Satellite standard[S].2011.
[3]周家喜.非协作通信中连续相位调制信号盲解调关键技术研究[D].合肥:中国科学技术大学,2009.
[4]Bianchi P,Loubaton P,Sirven F.On the blind estimation of the parameters of continuous phase modulated signals[J].IEEE Trans.Communications,2005,23(5):944-962.
[5]王宁,彭华,崔伟亮.一种非数据辅助的连续相位调制信号符号速率估计算法[J].信号处理,2010,26(12):1864-1869.
[6]隋丹,葛临东.一种基于DWT-CWT的CPFSK信号盲符号速率估计算法[J].系统仿真学报,2008,20(16):4269-4272.
[7]Corazza G E,Salmi P,Vanelli-Coralli A,et al.Differential and non-Coherent post detection integration techniques for the return link of satellite W-CDMA systems[C]//Proceeding of IEEE Personal Indoor and Mobile Radio Communications.2002:300-304.
[8]Corazza G E,Pedone R.Generalized and average post detection integration methods for code acquisition[C]//Proceeding of the IEEE Int.Symposium on Spread Spectrum Techniques and Applications.2004:207-211.
[9]Cioni S,Corazza G E.Unified Frame Acquisition and Symbol Timing Estimation for CPM Return Link Transmission[C]//IEEE Global Telecommunications Conference.2007:1519-1523.
[10]王勇军,彭华.卫星回传链路CPM信号调制识别研究[J].信息工程大学学报,2013,14(3):347-352.