| 摘要 |
A digital down converter (DDC) can be provided in a digital radio receiver front end to separate quadrature signals with narrow and wide filtering dependent upon the nature of the signals. A wide band filter can be used to pass digital radio signals to a digital radio receiver, while a narrow band filter can be used to pass signals related to analog AM/FM radio reception. The front end separates the quadrature signals according to the two different radio receivers after receiving a single IF signal from a digital radio tuner. The system and method of the present invention permits more accurate filtering of the respective digital and analog signals, while reducing receiver complexity and cost. An analog filter in the digital radio tuner can be replaced with a digital filter due to the relaxed specifications permitted by the DDC according to the present invention.
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