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| Authored by: Anonymous on Thursday, March 14 2013 @ 01:24 PM EDT |
That is not the decision. That is someone's miss-interpretation of the
decision. If the law were as you describe, then how would these patents be
possible?
http://www.google.com/patents/US6938064?dq=fast+fourier+transform+method&ei=
7QRCUabXIaLCyQGauIHwAw&cl=en
1. A method of calculating a fast Fourier transform or an inverse fast Fourier
transform of a digital signal defined by a series of N real starting samples
x(n), with N a power of two and n ε [0 . . . N−1], the method
comprising the steps of:
transforming input samples into output samples in a first transformation
step;
transforming input samples into output samples in at least one successive
transformation step to the first transformation step; and
storing the input samples and output samples of each transformation step in
a storage memory;
wherein each of the transformation steps is performed by means of a single
set of butterfly circuits with several inputs and several outputs, the operating
mode of the set of butterfly circuits modified selectively in each
transformation step, a series of N output samples y(n) representative of the
fast Fourier transform or the inverse fast Fourier transform of the output
samples x(n) being provided in a last transformation step;
wherein output samples y(n) are real;
wherein output samples of a butterfly circuit replace the corresponding
input samples of the same rank in the storage memory, so that, if the starting
samples x(n) processed in the first transformation step are classified in
bit-reversed order of their index n, output samples y(n) are provided in the
last transformation step in ascending order of index n and are defined by the
following relations:
description="In-line Formulae" end="lead"y(0)=Re[X(0)],
description="In-line Formulae" end="tail"
description="In-line Formulae"
end="lead"y(n)=Re[X((n+1)/2] for n being odd and different from
N−1, description="In-line Formulae" end="tail"
description="In-line Formulae" end="lead"y(n)=Im[X(n/2)]
for n being even and different from 0, and description="In-line
Formulae" end="tail"
description="In-line Formulae"
end="lead"y(N−1)=Re[X (N/2)]; and description="In-line
Formulae" end="tail"
wherein samples X (n), with n ε [0 . . . N−1], designate
complex samples of the series corresponding to the fast or inverse fast Fourier
transform of the starting samples series x(n).
http://www.google.com/patents/US6356926?dq=fast+fourier+transform+method&ei=
7QRCUabXIaLCyQGauIHwAw&cl=en
1. A method of calculating FFT, IFFT or like transforms with the aid of a
calculating unit and at least two memories, said calculating unit reading input
values from memory positions in the memories, performing one or more
calculations that require at least two input values and writing the output
values resulting from said calculations into corresponding memory positions in
the memories, wherein at least two groups of calculations may be commenced
simultaneously by virtue of the following method steps:
reading the input values for calculation in different groups of calculation
into the calculating unit and storing said input values in at least one first
intermediate storage device;
determining when all input values necessary for a current group of current
calculations have been read into the calculating unit;
determining when the calculations in a preceding group of calculations have
terminated at least one first calculation step;
commencing the calculations in the current group of calculations when all
input values necessary for the current calculation group have been read into the
calculating unit and the calculations in the preceding group of calculations
have terminated at least one first calculation step;
determining when the output values from the preceding group of calculations
have been written;
storing the output values from the current group of calculations in at least
one intermediate storage device until the output values from the preceding group
of calculations have been written; and
writing the output values from one group of calculations back to the same
memory positions as those from which the input values were read, whereafter the
output values can function as new input values.
And this one from Sep 20, 2011:
http://www.google.com/patents/US8023401?dq=fast+fourier+transform+method&hl=
en&sa=X&ei=XwdCUfnXBKflyAHg6IGABA&ved=0CE4Q6AEwCTgy
9. A method for Fast Fourier Transform (FFT)/Inverse Fast Fourier Transform
(IFFT) comprising:
storing a first half of input data in a first region of a storage unit that
includes a first region and a second region, each of which includes a plurality
of memories with a certain size in a matrix configuration;
receiving a second half of the input data, performing a first-point FFT/IFFT
operation on the first half of the input data stored and the second half of the
input data, and storing the first-point FFT/IFFT operation result in the storage
unit;
performing a second-point FFT/IFFT operation on the first-point FFT/IFFTed
data, and updating the storage unit by the second-point FFT/IFFT operation
result; and
performing a third-point FFT/IFFT operation on the second-point FFT/IFFTed
data, and updating the storage unit for the second time by the third-point
FFT/IFFT operation result.[ Reply to This | Parent | # ]
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| Authored by: Anonymous on Thursday, March 14 2013 @ 01:33 PM EDT |
No. You said patents to FFT were against the law. I asked for a law.
If it helps, the U.S. Patent laws are codified in 35 U.S.C.[ Reply to This | Parent | # ]
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