Patent ID: 7552162

Claim:
A receiving apparatus employing a digital multi-carrier transmission method utilizing a real coefficient wavelet filter bank in digital demodulation, said apparatus comprising: a memory configured to store received waveform data, a butterfly operation unit including K stages of butterfly processors, each of the butterfly processors being operable to perform butterfly operation using received waveform data corresponding to one symbol obtained from the memory; and an orthogonal transformer configured to perform an orthogonal transform based on received waveform data corresponding to 2K symbols using results of the butterfly operation performed by the K stages of butterfly processors, wherein the memory stores the received waveform data corresponding to 2K or more symbols which are continuous on time axis, wherein a Kth stage of the butterfly operation unit directly receives the received waveform data from the memory and has 2K butterfly processors, and each of the 2K butterfly processors receives, at a same time from the memory, the received waveform data corresponding to the 2K symbols, and wherein each stage of the K stages of butterfly processors includes at least two of the butterfly processors which provide an output which is half the number of the waveform data input thereto, by adding the received waveform data input thereto with each other.