发明授权
US4363129A Method and means of minimizing simulcast distortion in a receiver when
using a same-frequency repeater
失效
当使用同频中继器时,在接收机中最小化联播失真的方法和方法
- 专利标题: Method and means of minimizing simulcast distortion in a receiver when using a same-frequency repeater
- 专利标题(中): 当使用同频中继器时,在接收机中最小化联播失真的方法和方法
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申请号: US215589申请日: 1980-12-11
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公开(公告)号: US4363129A公开(公告)日: 1982-12-07
- 发明人: Jona Cohn , Allen L. Davidson , Anthony P. van den Heuvel
- 申请人: Jona Cohn , Allen L. Davidson , Anthony P. van den Heuvel
- 申请人地址: IL Schaumburg
- 专利权人: Motorola, Inc.
- 当前专利权人: Motorola, Inc.
- 当前专利权人地址: IL Schaumburg
- 主分类号: H04B7/155
- IPC分类号: H04B7/155 ; H04B7/26 ; H04B14/00 ; H04H20/67 ; H04B7/16
摘要:
Simulcast distortion in a receiver when using a same-frequency repeater is minimized by applying double modulation to a signal that is broadcast to the same-frequency repeater. A voice signal is applied without delay as AM on a carrier to a modulation index of up to 30%, and the same signal is also applied as FM on the same carrier with a time delay equal to the time delay in the same-frequency repeater. The same-frequency repeater detects the AM and applies the detected signal as FM on a carrier that is rebroadcast. Received FM signals are thus delayed by substantially the same amount whether they are received from the original broadcast or the same-frequency repeater.
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