发明名称 Digital type telephone system having a conference function
摘要 This digital telephone conference system provides improved cancellation of reflective signals which cause echo-singing problems, such as caused by hydrid mismatches, for any number of telephone sets. Each telephone set is sequentially sampled for time sharing, and alternate samples are given opposite polarity signs before being summed, thereby making approximately half of the signals of opposite phase, for any number of telephone sets, for effective cancellation. Also, each member of the conference receives a sum signal of all telephone sets except his own.
申请公布号 US4203005(A) 申请公布日期 1980.05.13
申请号 US19780919917 申请日期 1978.06.28
申请人 TOKYO SHIBAURA ELECTRIC CO LTD 发明人 FUKUDA, TAKEO;MURAYAMA, HIDEAKI
分类号 H04M3/56;H04Q11/04;(IPC1-7):H04M3/56 主分类号 H04M3/56
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