Title:
振幅変調(AM)信号を処理する方法および装置
Document Type and Number:
Japanese Patent JP4235175
Kind Code:
B2
Abstract:
In order to protect against adjacent channel interference and the effects of weak signal in AM signal processing, pre- and post-AM demodulation filters ( 36 and 38 ) may be used where the bandwidth of both is varied in the same manner by a single controlling mechanism ( 34 ). In one embodiment, two or more cascaded filters ( 20, 24 or 22, 26 or 30,32 ) may be used for the pre- and post-demodulation filters where each of the cascaded filters has a same predetermined order and uses the same set of coefficients. In one embodiment, all cascaded filters are first order IIR filters, which reduces computation complexity. The use of a same set of coefficient for all the cascaded filters results in a same bandwidth for all filters and further reduces computation complexity. In an alternate embodiment, cascaded filters may be used for only one of the pre- and post-demodulator filters.
Inventors:
Hendricks, John
Banks, Bradley
Seaburg, Charles E.
Banks, Bradley
Seaburg, Charles E.
Application Number:
JP2004551451A
Publication Date:
March 11, 2009
Filing Date:
August 22, 2003
Export Citation:
Assignee:
Freescale Semiconductor, Inc.
International Classes:
H04B1/10; H03H17/02; H03H17/04
Domestic Patent References:
| JP10164919A | ||||
| JP2001119270A |
Attorney, Agent or Firm:
Mamoru Kuwagaki
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