公开(公告)号：US07110478B2

公开(公告)日：2006-09-19

申请号：US10119409

申请日：2002-04-09

申请人： Jingdong Lin ,  Justine Zhuang ,  Tong Zhao

发明人： Jingdong Lin ,  Justine Zhuang ,  Tong Zhao

IPC分类号： H03D1/00 ,  H04L27/06

CPC分类号： H04Q1/45

摘要： A method of detecting a tone signal from complex input samples r(n) in a wireless communication system is disclosed. The method comprises calculating the phase difference of the samples r(n) as a signal x(n). Next, the signal x(n) is filtered with a notch filter to generate a notched output y(n). The power of both the signal x(n) and the notched output y(n) is estimated. The ratio of the powers of the notched output y(n) and signal x(n) is calculated. The tone signal is detected if the ratio is below a predetermined threshold for a predetermined duration of time.