公开(公告)号：MY146218A

公开(公告)日：2012-07-31

申请号：MYPI20071568

申请日：2007-09-19

Applicant: MIMOS BERHAD

Inventor： ABDEL-SAMAD AYMAN AHMED MAHMOUD ,  SOUROUR ESSAM ABDEL-FATTAH SOUROUR

IPC: H04B7/26

Abstract: THERE IS DISCLOSED A METHOD AND APPARATUS ADAPTED FOR THE DETECTION OF A NARROW BAND SIGNAL IMMERSED IN A WIDE BAND SIGNAL. GENERALLY, THE CENTER FREQUENCY OF THE NARROW BAND SIGNAL IS KNOWN TO BE WITHIN AN AMBIGUITY REGION OF THE SIGNALS. THE AMBIGUITY REGION WILL BE PARTITIONED INTO N SECTIONS. EACH FRAME OF THE RECEIVED COMPOSITE SIGNAL (NARROW BAND + WIDE BAND) IS THEN FREQUENCY SHIFTED N TIMES DIGITALLY SUCH THAT, AFTER EACH SHIFT, ONE OF THE N SECTIONS CENTERED AT ZERO FREQUENCY. THE N FREQUENCY-SHIFTED COMPOSITE SIGNALS ARE FILTERED BY THE SAME LOW-PASS FILTER (62) AND THE N OUTPUTS ARE BUFFERED BY THE FRAME BUFFERING MEANS (54). WITH THIS PROCEDURE, THE NARROW BAND SIGNAL, IF PRESENT, WILL BE AT ONE OF THE N FILTERED OUTPUTS. TO DETECT THE NARROW BAND SIGGIIAL, EACH BUFFERED FILTER OUTPUT IS MULTIPLIED BY A DELAYED AND CONJJUGATED VERSION OF ITSELF A MOVING AVERAGE IS THEN APPLIED ON THE RESULT OF THE MULTIPLICATION AND THE MAXIMUM OF THE ABSOLUTE VALUE OF THE MOVING AVERAGE IS FOUND. IF THE LARGEST OF THE N MAXIMA IS LARGER THAN A THRESHOLD, THE NARROW BAND SIGNAL IS DETECTED AND IDENTIFIED AS THE CONTROL CHANNEL. HIGH SNR SAMPLES ARE SUBSEQUENTLY SELECTED FOR ESTIMATING THE FREQUENCY OFFSET OF THE NARROW BAND SIGNAL.

公开(公告)号：WO2009038450A3

公开(公告)日：2009-06-04

申请号：PCT/MY2008000104

申请日：2008-09-19

Applicant: MIMOS BERHAD ,  ABDEL-SAMAD AYMAN AHMED MAHMOU ,  SOUROUR ESSAM ABDEL-FATTAH SOU

Inventor： ABDEL-SAMAD AYMAN AHMED MAHMOUD ,  SOUROUR ESSAM ABDEL-FATTAH SOUROUR

IPC: H04B7/26

CPC classification number: H04L27/0014 ,  H04L2027/0083

Abstract: There is disclosed a method and apparatus adapted for the detection of a narrow band signal immersed in a wide band signal. Generally, the center frequency of the narrow band signal is known to be within an ambiguity region of the signals. The ambiguity region will be partitioned into N sections. Each frame of the received composite signal (narrow band + wide band) is then frequency shifted N times digitally such that, after each shift, one of the N sections centered at zero frequency. The N frequency-shifted composite signals are filtered by the same low-pass filter (62) and the N outputs are buffered by the frame buffering means (54). With this procedure, the narrow band signal, if present, will be at one of the N filtered outputs. To detect the narrow band signal, each buffered filter output is multiplied by a delayed and conjugated version of itself. A moving average is then applied on the result of the multiplication and the maximum of the absolute value of the moving average is found. If the largest of the N maxima is larger than a threshold, the narrow band signal is detected and identified as the control channel. High SNR samples are subsequently selected for estimating the frequency offset of the narrow band signal.

Abstract translation: 公开了一种适用于检测浸入宽带信号中的窄带信号的方法和设备。 通常，已知窄带信号的中心频率在信号的模糊区域内。 歧义区域将被划分为N个部分。 接收的复合信号（窄带+宽带）的每个帧然后被数字地频移N次，使得在每次移位之后，N个部分中的一个以零频率为中心。 N个频移后的合成信号由相同的低通滤波器（62）滤波，N个输出由帧缓冲装置（54）缓冲。 通过该程序，窄带信号（如果存在）将处于N个滤波输出中的一个。 为了检测窄带信号，将每个缓冲滤波器输出乘以其本身的延迟和共轭版本。 然后将移动平均值应用于乘法结果，并找到移动平均值的绝对值的最大值。 如果N个最大值中的最大值大于阈值，则检测窄带信号并将其识别为控制信道。 随后选择高SNR样本来估计窄带信号的频率偏移。