Pulse or digital communications – Receivers – Interference or noise reduction
Reexamination Certificate
2005-09-20
2005-09-20
Fan, Chieh M. (Department: 2634)
Pulse or digital communications
Receivers
Interference or noise reduction
C708S300000
Reexamination Certificate
active
06947509
ABSTRACT:
An oversampled filter bank structure that can be implemented using popular and efficient fast filter banks to allow subband processing of an input signal with substantially reduced aliasing between subbands. Even subbands (SB0, SB2, SB4, . . . ) of an input signal (x(n)) are frequency-shifted (212, 1012, 1012′, 1012″) prior to analysis filtering (214, 214′, 214″) at a 2× oversampled filter bank, subband processing (240, 240′, 240″), and synthesis filtering (216, 216′, 216″). A subsequent frequency-shift (218, 218′) returns the even subbands to their original band positions. The odd subbands (SB1, SB3, SB5, . . . ) are delayed (252) to compensate for the processing time of the frequency shifting. Separate analysis (214, 214′) and synthesis (216, 216′) filter banks may be provided for the even and odd subbands, or common complex analysis (284) and synthesis (286) filter banks may be used. In another embodiment, the subbands are processed in four subband paths (Paths0, 1, 2, 3), and4× oversampling is used. A filter bank structure (1400) for 2-D data is also provided.
REFERENCES:
patent: 4691292 (1987-09-01), Rothweiler
patent: 5297557 (1994-03-01), Reichl
patent: 5568142 (1996-10-01), Velazquez et al.
patent: 5732189 (1998-03-01), Johnston et al.
patent: 5745392 (1998-04-01), Ergas et al.
Smith, M.J.T. et al., “Analysis/Synthesis Techniques for Subband Image Coding,” IEEE Transactions on Acoustics, Speech, and Signal Processing, Aug. 1990, vol.38, No. 8, pp. 1446-1456.
Ramstad, T.A. et al., “Cosine-Modulated Analysis-Synthesis Filterbank with Critical Sampling and Perfect Reconstruction,” IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP-91, 1991, vol. 3, pp. 1789-1792.
Brennan, Robert, et al., “A Flexible Filterbank Structure for Extensive Signal Manipulations in Digital Hearing Aids,” IEEE, 1998.
Harteneck, M., et al., “A Filterbank Design for Oversampled Filter Banks without Aliasing in the Subbands,” TFTS 97, Aug. 27-29, 1997, Warwick, UK.
Fan Chieh M.
Lipsitz & McAllister LLC
Verance Corporation
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