曹帅　王布宏　刘新波　沈海鸥

摘要：

针对基于随机上下文无关文法（SCFG）建模的多功能雷达（MFR）概率学习问题，在传统InsideOutside（IO）算法和ViterbiScore（VS）算法的基础上，提出一种基于Earley算法的多功能雷达文法概率快速学习算法。该算法通过对截获的雷达数据进行预处理，构造可以反映派生过程的Earley剖析表，并且基于最大子树概率原则从剖析表中提取出最优剖析树，利用改进的IO算法和改进的VS算法对文法概率进行学习，实现MFR参数估计，得到文法参数后，再利用Viterbi算法对MFR状态进行估计。理论分析和实验仿真表明，与IO算法和VS算法相比，改进算法在保持估计精度的同时，可以有效降低计算复杂度和减少运行时间，验证了Earley算法能够提高文法概率的学习速度。

关键词：

随机上下文无关文法；多功能雷达；文法概率快速学习算法【只是本文提出的算法吧；Earley算法；参数估计；状态估计

中图分类号：

U416.216

文献标志码：A

Abstract：

To deal with the probability learning problem in MultiFunction Radar （MFR） based on Stochastic ContextFree Grammar （SCFG） model， a new fast learning algorithm of grammatical probabilities in MFR based on Earley algorithm was presented on the basis of traditional InsideOutside （IO） algorithm and ViterbiScore （VS） algorithm. The intercepted radar data was preprocessed to construct an Earley parsing chart which can describe the derivation process. Furthermore， the best parsing tree was extracted from the parsing chart based on the criterion of maximum subtree probabilities. The modified IO algorithm and modified VS algorithm were utilized to realize the learning of grammatical probabilities and MFR parameter estimation. After getting the grammatical parameters， the state of MFR was estimated by Viterbi algorithm. Theoretical analysis and simulation results show that compared to the conventional IO algorithm and VS algorithm， the modified algorithm can effectively reduce the computation complexity and running time while keeping the same level of estimation accuracy， which validates that the grammatical probability learning speed can be improved with the proposed method.

英文關键词Key words：

Stochastic ContextFree Grammar （SCFG）； MultiFunction Radar （MFR）； grammatical probabilities fast learning algorithm； Earley algorithm； parameter estimation； state estimation

0引言

雷达告警接收机（Radar Warning Receiver， RWR）系统通过测量与分析照射到载机上的雷达信号，对截获雷达数据与雷达威胁数据库中的数据进行匹配来确定威胁雷达辐射源的类型、工作状态、方位、威胁等级等信息，从而对飞行员提供有效建议，采取有效措施[1]。对于常规体制雷达，采用基于参数的雷达告警技术[2]便可对雷达辐射源型号和工作状态进行有效识别。多功能雷达（MultiFunction Radar， MFR）为新体制雷达，是一种有源相控阵火控雷达[3]，采用电子扫描技术和复杂的软件算法对波束进行控制，极大地提高了目标探测和跟踪能力；……