| US 7,555,509 B2 | ||
| Parallel fast Fourier transformation method of concealed-communication type | ||
| Yusaku Yamamoto, Nagoya (Japan); and Ken Naono, Tachikawa (Japan) | ||
| Assigned to Hitachi, Ltd., Tokyo (Japan) | ||
| Filed on Feb. 25, 2004, as Appl. No. 10/785,110. | ||
| Claims priority of application No. 2003-145607 (JP), filed on May 23, 2003. | ||
| Prior Publication US 2004/0236810 A1, Nov. 25, 2004 | ||
| Int. Cl. G06F 17/14 (2006.01) | ||
| U.S. Cl. 708—401 [708/404] | 6 Claims |
| 1. A method for improving efficiency in processing a data array in a parallel-processing computer having an input apparatus,
a plurality of processors coupled with each other, an output apparatus, and an external storage apparatus, each of the processors
having a memory, the method comprising the steps of:
dividing the data array into a plurality of data portions with at least one of the processors;
storing the plurality of data portions into any of said memories;
dividing said plurality of the data portions into a plurality of data parts;
determining whether each of the data parts is a first data part or a second data part based on order of each of the data parts
in the data array, said first data part being even-numbered data of said data array in a direction of a second axis and said
second data part being odd numbered data of said data array in the direction of said second axis;
carrying out first processing which is Fourier transformation of said first data part along a direction of a first axis with
each processor while transferring the data parts among the processors;
relocating results of said first processing among the plurality of processors; and
carrying out second processing which is a Fourier transformation of said second data part along the direction of said first
axis with the each processor while transferring the relocated results among the processors.
|