The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 25, 1997
Filed:
Feb. 01, 1996
Terry L Williams, Melbourne Beach, FL (US);
AirNet Communications Corporation, Melbourne, FL (US);
Abstract
In a cellular-telephone-system base-station receiver's channelizer (111), frequency translation of the outputs of a filter bank (FIG. 5) implemented in fast-Fourier-transform circuitry (453,455,460) is achieved by rotating the correspondence between FFT input elements and the filter coefficients by which multipliers (437) multiply incoming samples to produce them. Specifically, a storage-address generator (482) directs that corresponding FFT input elements of successive FFT operations be stored in the same locations in an input-data memory (451). To retrieve those values for use in the DFT operation, however, a fetch-address generator (484) employs a modulo-K adder (488) to impose a changing offset so that the starting address for retrieval of each FFT operation's input record changes between FFT operations by the filter bank's decimation rate M. An FFT-implemented combiner (131) similarly rotates computation values to phase align successive wavelets that it adds together to generate modulated carriers in a multi-channel output signal.