Abstract:
The present invention relates to a method for estimating a location of a threat by resolving an ambiguity of selecting radar pulses and, more specifically, to a method for estimating a location of a threat by resolving an ambiguity of selecting radar pulses in a Time Difference Of Arrival (TDOA) system based on a genetic algorithm. The method of the present invention is configured to resolve the ambiguity of selecting the radar pulses for the threat having a small pulse repetition period value against a separation distance between electronic devices receiving the radar pulse and configured to be able to complement the weakness of a position estimation system using the TDOA with accuracy and fast convergence speed.
Abstract:
The present invention relates to a radar signal recognition technique and, more specifically, to a method of recognizing a complex pulse repetition interval (PRI) modulation type through a support vector machine (SVM) by generating an exponential moving average signal using time of arrival (TOA) information of collected pulses and extracting a distinguishing factor after generating a signal by layer based on the exponential moving average signal.
Abstract:
The present invention relates to a method for recognizing a user-adaptive cursive script in a smart device based on state transition probability. The method is realized in a manner of allowing a recognizer to train a cursive script inputted by a user, making a chain code, generated from the cursive script, into a state transition probability matrix, providing the recognizer with each of cursive script discriminating factors (P1-P9) extracted from the state transition probability matrix and then outputting the recognition result, terminating the recognition of the cursive script, when the recognition result is normal, and receiving a request for characters intended by the user and allowing the recognizer to retrain the characters, when the recognition result is abnormal. Thus, a writing style of a user can be recognized quickly with a high accuracy, a fast writing style (cursive script) with stronger user-specific font characteristics can be recognized as an exact writing style and, in particular, the poor performance and use of current smart devices can be extended by improving the character recognition of the smart devices.
Abstract:
PURPOSE: A method and a device for recognizing a pulse repetition interval (PRI) modulation form using a support vector machine (SVM) are provided to minimize an error rate in pattern recognition. CONSTITUTION: A receiving part (10) senses a radar signal to process and deliver to a control part (20). The control part is classified into an SVM training module (22), an input data characteristic vector extracting module (24), a classification result value check module by SVM (26), and a PRI modulation form discrimination module (28) in order to implement a PRI modulation form recognizing method. The SVM training module extracts a feature vector to input to an SVM from training data and includes the extracted feature vector and a PRI modulation form value. The SVM training module classifies the input data to input to SVM and trains the SVM by modulation forms using the input data. The classification result value check module by SVM puts the feature vector into the SVM by modulation forms implemented by the SVM training module. The PRI modulation form discrimination module selects a SVM with the greatest value among discrimination result values, produces a result code according to the selected SVM number, and recognizes the PRI modulation form using the result code. [Reference numerals] (10) Receiving unit; (20) Control unit; (22) SVM training module; (24) Input data characteristic vector extraction module; (26) SVM classification result check module; (28) PRI modulation type classifying module
Abstract:
PURPOSE: A signal source location estimating method and a signal source location estimating apparatus using the same are provided to simultaneously use time difference of arrival (TDOA) and frequency difference of arrival (FDOA), thereby improving the accuracy of location estimation. CONSTITUTION: A signal source location estimating method includes following steps. A location and speed vector estimation value about the location and speed vector of a radar signal source is set, and an initial value about transmission value is set (S110). A TDOA and FDOA estimation value is calculated using the location and speed vector estimation value and the transmission value set by the initial value (S120). A difference value between a TDOA and FDOA measurement value measured in a receiving part and the TDOA and FDOA estimation value is calculated (S130). A Jacobian matrix is generated by differentiating each of a TDOA model equation and an FDOA model equation which are prepared in advance using the TDOA and FDOA estimation value (S140). A weighted value for altering the location and speed vector estimation value is calculated using the difference value and the Jacobian matrix, and the location and speed vector estimation value is altered using the weighted value (S150). In case the difference value is higher than a permissible threshold value or the repeated number of control procedures in previous steps is lower than a maximum value, the control procedures in the previous steps are performed again (S160). If the difference value is lower than the permissible threshold value and the repeated number of the control procedures is higher than the maximum value, an altered location and speed vector estimation value is determined as a final location speed vector of the radar signal source (S170). [Reference numerals] (AA) Start; (BB) End; (S110) Set an initial value; (S120) Calculate a TDOA and FDOA estimation value; (S130) Calculate the difference value between a TDOA and FDOA measurement value and the TDOA and FDOA estimation value; (S140) Generate a Jacobian matrix; (S150) Alter the location and speed vector estimation value; (S160) Confirm whether the difference value is higher than a permissible threshold value; (S170) Determine the location and speed
Abstract:
본 발명은 다채널 디지털 수신 방법 및 장치에 관한 것으로, 다수 개의 안테나로부터 수신되는 N(N은 4 이상의 자연수)개 이상의 RF 신호를 A/D변환하여 디지털 신호로 변환하는 AD 변환기(ADC); AD 변환기로부터 N개 채널에서 디지털 신호를 입력받아 채널별 신호의 전력(power) 측정 후, 그 정보를 이용한 수신 신호의 세기가 가장 큰 채널(Max 채널)과 2번째, 3번째 채널(Max 채널의 좌, 우 채널)의 수신 채널을 선택하는 Power 측정 및 채널 선택부; Power 측정 및 채널 선택부에 의해 선택된 Max 채널의 신호에서 내부 또는 외부 고정밀 시각정보를 이용하여 수신신호의 세기가 가장 큰 신호에 대해 수 ns 해상도를 갖는 TOA를 측정하는 고해상도 TOA 측정부; Power 측정 및 채널 선택부에 의해 선택된 Max, 2nd, 3rd 채널에서 channelizer 필터를 사용하여 신호의 주파수, 신호 세기, 펄스폭을 측정하고, phase detector로 신호의 위상을 측정하는 채널라이저/위상 검출기; 채널라이저/위상 검출기로부터 제공된 각 채널별 동일한 주파수에 해당하는 신호의 위상과 세기를 동시에 이용하여 AOA를 측정하는 AOA 측정부; 및 고해상도 TOA 측정부, 채널라이저/위상 검출기, 및 AOA 측정부에서 각각 측정된 결과를 조합하여 펄스 단위로 PDW를 생성하는 PDW 생성부를 포함하고, 4개 이상의 수신 안테나 신호로부터 고해상도 TOA 측정이 가능하고, 동시에 펄스단위로 신호의 PDW 생성이 가능하다.
Abstract:
A method for recognizing PRI(Pulse Repetition Interval) modulation types of a radar signal by using a type classifier is provided to exactly recognize the PRI modulation type for a pulse train passing a pulse train separation process of a radar signal receiving and processing system under high-density multi-radar signal environment. A method for recognizing PRI(Pulse Repetition Interval) modulation types of a radar signal by using a type classifier comprises the steps of: aligning pulse arrival time information from pulse information of a received radar signal in order of time(10); generating a PRI sequence through first difference of the pulse arrival time(20); compensating an omitted pulse signal frequently generated under the real electromagnetic wave signal environment(30); calculating linear autocorrelation for a zero-center signal and normalizing the linear autocorrelation as a maximum value(40); extracting the first type classifier from the normalized linear autocorrelation(50); extracting the second type classifier from the normalized linear autocorrelation(60); compensating PRI modulation type distortion by the other emitter signal(70); computing the linear autocorrelation for a zero-center signal and normalizing the linear autocorrelation as a maximum value(80); extracting the third and fourth type classifiers from the normalized linear autocorrelation obtained through re-operation(90,100); and recognizing the PRI modulation type of the radar signal by comparing the type classifiers extracted in each step, with a pre-determined critical value for classifying the types.