发明名称 |
Digital demodulator with interpolation for linearly amplitude-modulated data signals |
摘要 |
A digital demodulator of data signals transmitted by linear amplitude modulation of a carrier, sampled under the control of clock pulses CK1, comprises an interpolating unit UIN including a tapped delay line TDL whose outputs carry, at a given instant, respective signal samples received during different clock cycles. These signal samples are fed to a transversal filter FIN also receiving two sets of interpolation coefficients ak, bk read out from respective memory sections ME1, ME2. The signal samples from the several delay-line taps are multiplied in filter FIN by the two sets of coefficients ak and bk, under the control of a pulse train CK2 and another pulse train CK3 of the same cadence but phase-shifted with reference to the former, and the two sets of resulting products are respectively summed in a digital adder SM and alternately read out to a phase corrector CJ recovering the phase coherence of the demodulated baseband signal.
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申请公布号 |
US4121165(A) |
申请公布日期 |
1978.10.17 |
申请号 |
US19770790081 |
申请日期 |
1977.04.22 |
申请人 |
CSELT - CENTRO STUDI E LABORATORI TELECOMUNICAZIONI S.P.A. |
发明人 |
DOGLIOTTI, RENATO;MAZZEI, UMBERTO;MENGALI, UMBERTO |
分类号 |
H04L27/06;(IPC1-7):H03D1/02;H03K9/02 |
主分类号 |
H04L27/06 |
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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