公开(公告)号：WO1995015639A1

公开(公告)日：1995-06-08

申请号：PCT/US1994012280

申请日：1994-10-25

Applicant: MOTOROLA INC.

Inventor： MOTOROLA INC. ,  LOVE, Robert, Tristan ,  STEWART, Kenneth, A. ,  RAPALA, Bryan

IPC: H04L27/30

CPC classification number: H04L27/2275 ,  H04B1/707

Abstract: The present invention provides a downconverter method and apparatus for downconverting a multiphase modulated signal. The downconverter can be implemented in a multi-phase receiver such as a quadrature receiver. An analog-to-digital converter (103) converts an intermediate frequency signal to a digital signal at a sampling rate. A Hilbert transformation filter (104) and a delay element (105) connected in parallel provide respective passband quadrature and in-phase components of the digital signal. A digital translator (107) alters the passband quadrature and in-phase components based on a predetermined pattern to provide a baseband quadrature signal and a baseband in-phase signal. The digital translator (107) can be a pseudorandom sequence demodulator for demodulating a code division multiple access (CDMA) signal. Various types of DC estimation can also be provided in addition to automatic gain control.

Abstract translation: 本发明提供一种用于下变频多相位调制信号的下变频器方法和装置。 下变频器可以在诸如正交接收机的多相接收机中实现。 模数转换器（103）以采样速率将中频信号转换为数字信号。 并联连接的希尔伯特变换滤波器（104）和延迟元件（105）提供数字信号的各个通带正交和同相分量。 数字转换器（107）基于预定模式改变通带正交和同相分量，以提供基带正交信号和基带同相信号。 数字转换器（107）可以是用于解码码分多址（CDMA）信号的伪随机序列解调器。 除了自动增益控制之外，还可以提供各种类型的直流估计。