| 摘要 |
An active signal suppression system utilizes multi-rate recombinant transmultiplexer (56) to suppress or cancel an undesired signal (46) from a wideband composite signal (40) to be applied to an analog to digital converter (20). The transmultiplexer (56) includes a first demultiplexer (88,90), multiplier (100), switch (120), and multiplexer (128,130). The demultiplexer and multiplexer each have a poly phase filter and Fast Fourier Transform pair which permit channelization and facilitate the generation of a cancellation signal (145) for suppression of the undesired signal. Signal cancellation circuit (60) receives the composite signal (40) at one input (70) and the cancellation signal (145) at another input (76). A minimum mean square estimation circuit (MMSE) (158) and a second demultiplexer (145, 146) are included in a feedback circuit to provide error correction. A detector and automatic gain control circuit (138) is coupled to the first demultiplexer (88,90) and the multiplier (100) to detect the undesired signal (46) for controlling the switch and to provide automatic gain control to a variable gain amplifier (214) connected to the signal cancellation circuit.
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