发明名称 |
Auto-threshold / adaptive equalizer. |
摘要 |
<p>An auto-threshold circuit in accordance with the present invention comprises a full-wave peak sensor for accurately estimating slice levels for input signal detection. The peak sensor is qualified such that the auto-threshold circuit does not track an input signal with no modulation. The input signal is windowed with a phase-locked-loop so that the peak sensor is coherent to the input signal, causing the circuit to be insensitive to noise spikes or input distortion outside the window. The auto-threshold circuit includes a digital loop filter which receives the output from an auto-threshold controller and generates a corresponding binary signal which is converted by a digital Sigma/delta modulator to a single bit pulse density modulated signal having a predetermined sampling frequency. An adaptive equalizer in accordance with the present invention shares the auto-threshold slicing signal for generating its error feedback signal. The adaptive equalizer comprises a frequency selector which generates an output signal in response to the input signal and the feedback signal. As stated above, a threshold comparator slices the equalizer output at predetermined levels. A controller receives the comparator output and provides a controller output representative of the voltage level of the comparator output. A digital filter is then utilized to generate a corresponding binary signal as the feedback signal to the frequency selector. The adaptive equalizer is operable at more than one speed.</p> |
申请公布号 |
EP0311972(A2) |
申请公布日期 |
1989.04.19 |
申请号 |
EP19880116846 |
申请日期 |
1988.10.11 |
申请人 |
NATIONAL SEMICONDUCTOR CORPORATION |
发明人 |
WONG, HEE |
分类号 |
H04B3/06;H04L25/03;H04L25/06;H04L25/30 |
主分类号 |
H04B3/06 |
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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