Abstract: An implement method of a FFT processor comprises the following steps. First, a 21 point FFT processor, which has an output and an input receiving a 2n+1 point data, is provided. A 2n-point FFT processor having an input and an output is provided. Sequentially, a multiplexer, which has a first input coupled to the output of the 21 point FFT processor, a second input receiving a 2n point data and an output coupled to the input of the 2n point FFT processor, is provided. When an input data is a 2n point data, the second input of multiplexer is coupled to the output thereof, and when an input data is a 2n+1 point data, the first input of multiplexer is coupled to the output thereof.

Abstract: Computing an angle between a real part and an imaginary part of a complex number includes receiving complex number data; generating a first value, a second value and a determination result according to the complex number data; choosing a dividend and a divisor of a division operation from the first value and the second value for generating a division result according to magnitudes of the first value and the second value; performing table look-up for the division result to generate a table look-up result according to a preserved table; and adjusting the table look-up result for generating an angle corresponding to the complex number data according to the determination result.

Abstract: An implement method of a FFT processor comprises the following steps. First, a 21 point FFT processor, which has an output and an input receiving a 2n+1 point data, is provided. A 2n-point FFT processor having an input and an output is provided. Sequentially, a multiplexer, which has a first input coupled to the output of the 21 point FFT processor, a second input receiving a 2n point data and an output coupled to the input of the 2n point FFT processor, is provided. When an input data is a 2n point data, the second input of multiplexer is coupled to the output thereof, and when an input data is a 2n+1 point data, the first input of multiplexer is coupled to the output thereof.