公开(公告)号：WO9746989A9

公开(公告)日：2004-03-18

申请号：PCT/US9707959

申请日：1997-05-09

Applicant: SENSORMATIC ELECTRONICS CORP

Inventor： FREDERICK THOMAS J ,  GOODRICH STEVEN ,  BETTINE DALE R

IPC: G08B13/24 ,  G08B13/187

CPC classification number: G08B13/2488 ,  G08B13/2471

Abstract: An electronic article surveillance system (100) includes a signal generator (22, 24, 26) for generating an interrogation signal (28) in an interrogation zone (30), an antenna (36) which receives a signal (34) present in the interrogation zone (30), and circuitry for cancelling interference. A hybrid interference component cancelling loop forms a digital interference estimate signal (108) which is converted (106) into an analog estimate signal, which is subtracted (102) from an input analog signal (40). The difference signal is digitized and subjected to additional digital interference cancellation processes (108). Each of the signal processing operations (108) entails performing a polyphase decomposition of a digital input signal, estimating a mean value of each of the resulting subsequences, and combining the estimated mean values to form an interference component estimate signal. An input sample window for a comb-filtering stage is phase adjusted relative to the interrogation signal to compensate for changes in phase of the marker signal (34).

Abstract translation: 电子物品监视系统（100）包括用于在询问区（30）中产生询问信号（28）的信号发生器（22,24,26），接收存在于所述询问区（30）中的信号（34）的天线 询问区（30）和消除干扰的电路。 混合干扰分量消除环形成数字干扰估计信号（108），其被转换（106）为模拟估计信号，其从输入模拟信号（40）中减去（102）。 差分信号被数字化并经受附加的数字干扰消除处理（108）。 每个信号处理操作（108）需要执行数字输入信号的多相分解，估计所得到的子序列中的每一个的平均值，并组合估计的平均值以形成干扰分量估计信号。 用于梳状滤波级的输入采样窗口相对于询问信号进行相位调整，以补偿标记信号（34）的相位变化。