Abstract:
PURPOSE: A fast Fourier transform device for a software definition wireless system based on MIMO(Multi Input Multi Output)-OFDM(Orthogonal Frequency Division Multiplexing) and a method are provided to support multiple channel input based on a MDC(Multi-path Delay Communicator) structure, thereby corresponding to a MIMO structure of various kinds. CONSTITUTION: A radix-3 butterfly module(560) selectively processes input data with a channel corresponding to received distance selection information. A first variable distance selection module is composed of multiplexers selecting one of the input data and output for the radix-3 butterfly module corresponding to the distance selection information. A data mapping module(510) reconstructs output data of the first variable distance selection module in parallel. Radix-2/2/4/2 butterfly modules(521-524) are successively arranged. [Reference numerals] (510) Data mapping module; (521) Butterfly module [R2BM1]; (522) Butterfly module [R2BM2]; (523) Butterfly module [R4BM1]; (524) Butterfly module [R2BM2]; (525) Butterfly module [R4BM1]; (526) Butterfly module [R2BM2]; (527) Butterfly module [R4BM2]; (528) Butterfly module [R2BM3]; (540) Clock distribution module; (550) Data rearrangement module; (560) Butterfly module [R3BM]; (AA) 1~4 channel data; (BB) Output