Abstract: 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.

Abstract: 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.

Abstract: A receiver performs rapid adaptive interference canceling for use in despreading multiple CDMA channels sharing the same RF front end. The receiver includes a buffer (22) for providing for overlapping time samples and rate adaptation, a windowing function (24) for improving interference rejection capability and a FFT (26) for calculating the input power spectrum. The receiver further includes a circuit (28, 30) to whiten the input power spectrum. The whitened power spectrum is multiplied (32) against the frequency domain version of different spreading sequences and the inverse FFT (40) of the product is performed. The output of this inverse FFT is buffered (44) to provide multiple despread output channels, with a plurality of code phases for further processing.