Signal processing apparatus
AssigneeNEC Corporation
InventorAtsufumi Shibayama
Life of this patent
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Abstract
A signal processing apparatus that performs inverse fast Fourier transform (IFFT) on N pieces of input data where N is a positive integer greater than or equal to 3 and not a power of 2, includes a butterfly operation processing circuit configured to perform butterfly operation processing on the input data, a converted twiddle factor operation processing circuit configured to perform twiddle factor operation processing using a converted twiddle factor coefficient obtained by multiplying a twiddle factor operation coefficient for IFFT by M/N, a 1/M operation circuit configured to perform 1/M operation, where M is a power of 2, on output data to output the result of the operation.
Claims10
A signal processing apparatus that performs an inverse fast Fourier transform (IFFT) on N pieces of input data, where Nis a positive integer greater than or equal to 3 and not a power of 2, the apparatus including:
- a butterfly operation processing circuit configured to perform butterfly operation processing on the N pieces of input data;
- a converted twiddle factor operation processing circuit configured to perform twiddle factor operation processing using converted twiddle factor coefficients, each obtained by multiplying each original twiddle factor coefficient for the IFFT by M/N;
- and
- a 1/M operation circuit configured to perform 1/M operation processing on N pieces of output data, where M is a power of 2, to output result of the operation as N-points of output data of the IFFT.
A signal processing apparatus including:
- a fast Fourier transform apparatus configured to perform a fast Fourier transform (FFT) on every consecutive N pieces of input time-domain data where N is a positive integer, not a power of 2;
- a converted filter operation apparatus configured to multiply each of N pieces of frequency-domain data generated by the fast Fourier transform apparatus by each converted filter coefficient obtained by multiplying each filter coefficient for frequency-domain equalization by (M/N), where M is a power of 2;
- and
- an inverse fast Fourier transform apparatus that receives N pieces of frequency-domain data output from the converted filter processing apparatus to perform an inverse fast Fourier transform (IFFT) on the N pieces of frequency-domain data, wherein
- the inverse fast Fourier transform apparatus includes:
- a butterfly operation processing circuit configured to perform butterfly operation processing on the N pieces of frequency-domain data received;
- a twiddle factor operation processing circuit configured to perform twiddle factor operation processing using twiddle factor coefficients for the IFFT;
- and
- a 1/M operation circuit configured to perform 1/M operation processing on N pieces of output data to output the result of the operation.
A signal processing apparatus that performs at least one of:
- N-point discrete Fourier transform (DFT) processing,
- N-point inverse discrete Fourier transform (IDFT) processing,
- N-point fast Fourier transform (FFT) processing, or
- N-point inverse fast Fourier transform (IFFT) processing, where N is a positive integer, not a power of 2, the apparatus including:
- a first circuit configured to perform butterfly operation processing for N-points of input data;
- a second circuit configured to multiply each of the N-points of input data by a converted twiddle factor coefficient obtained by multiplying a twiddle factor coefficient by (M/N), where M is a power of 2;
- and
- a third circuit configured to perform 1/M operation for N-points of output data, the multiplication of the twiddle factor coefficient by (M/N) and the 1/M operation configuring 1/N scaling to the N points of output data.
Dependencies are inferred from the claim text.