Patent ID: 8554818

Claim:
A time-domain to frequency-domain signal processing method, comprising: pre-processing, by a digital signal processor, time-domain data; pre-rotating, by a digital signal processor, the pre-processed data by using a rotation factor a·W N n+0.5 ; performing, by a digital signal processor, a discrete Fourier transform (DFT) of N/4 points on the pre-rotated data; and post-rotating, by a digital signal processor, the data transformed by the DFT by using a rotation factor b·W N k+0.5 to obtain frequency-domain data; where: a and b are constants, N is the length of the time-domain data, W N = ⅇ - j ⁢ 2 ⁢ π N , ⁢ W N n + 0.5 = ⅇ - j ⁢ 2 ⁢ π N ⁢ ( n + 0.5 ) , ⁢ W N k + 0.5 = ⅇ - j ⁢ 2 ⁢ π N ⁢ ( k + 0.5 ) , n=0, . . . , N/4−1 and k=0, . . . , N/4−1.