FREQUENCY OFFSET CORRECTING CIRCUIT

专利名称：FREQUENCY OFFSET CORRECTING CIRCUIT发明人：Hidehito Aoyagi,Botaro Hirosaki申请号：US06/643792申请日：19840824公开号：US04604583A公开日：19860805

摘要：A second-order phase-locked loop (PLL) is provided following a demodulatingsection which is arranged to detect the baseband signals of incoming parallel channelsignals. The second-order PLL, which is supplied with a baseband signal of a pilot channelfrom the demodulating section, includes a first and second control loops. The firstcontrol loop is adapted to correct a static phase shift of the pilot channel signal, whilethe second control loop functions to correct an abrupt frequency offset of same. Thesecond-order PLL is further utilized to correct both static phase shifts and abruptfrequency offsets of data channels (viz., channels other than the pilot channel). A thirdcontrol loop is further provided which extends between the second-order PLL and theinput of the demodulating section, and which has a function by which static or slowlychanging frequency offsets of the channels are compensated.

申请人：NEC CORPORATION

代理机构：Schwartz, Jeffery, Schwaab, Mack, Blumenthal & Evans

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