发明名称 |
Linear phase robust carrier recovery for QAM modems |
摘要 |
In a QAM demodulator including an adaptive equalizer, a method of carrier tracking comprising the following steps is disclosed: (A) sampling a QAM signal received from a transmission channel; (B) recovering a symbol clock function from the sampled QAM signal; (C) applying the sampled QAM signal to the adaptive equalizer in order to obtain a QAM equalized signal in a Blind Equalization (BE) mode; (D) using a slicer to locate a nearest plant point for the QAM Blind equalized signal for each recovered symbol clock; (E) using a complex conjugate multiplier to obtain an instantaneous inphase component and an instantaneous quadrature component of a phase angle error signal; (F) using a linear phase detector to obtain an instantaneous phase angle error for each symbol clock; (G) averaging the instantaneous phase angle error signal by using a carrier loop filter; (H) using a complex multiplier to insert an inverse of the averaged phase angle error signal into the QAM Blind equalized signal to compensate for the carrier phase angle error; and (I) repeating the steps (D-H) to close a carrier frequency loop.
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申请公布号 |
US6904098(B1) |
申请公布日期 |
2005.06.07 |
申请号 |
US20010981085 |
申请日期 |
2001.10.16 |
申请人 |
WIDEBAND SEMICONDUCTORS, INC. |
发明人 |
ISAKSEN DAVID BRUCE;DANZER BYRON ESTEN |
分类号 |
H03J7/02;H04L5/12;H04L25/03;H04L25/06;H04L27/00;H04L27/38;(IPC1-7):H04L5/12 |
主分类号 |
H03J7/02 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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