Howtosignalprocessing
- What is bit reversal in FFT?
- How is bit reverse addressing used in FFT computations?
- How many twiddle factors are required for computing 32 point FFT?
What is bit reversal in FFT?
Bit reversal is most important for radix-2 Cooley–Tukey FFT algorithms, where the recursive stages of the algorithm, operating in-place, imply a bit reversal of the inputs or outputs. Similarly, mixed-radix digit reversals arise in mixed-radix Cooley–Tukey FFTs.
How is bit reverse addressing used in FFT computations?
Bit-reversed addressing is a special feature provided in the dsPIC® architecture to support efficient implementation of FFT algorithms. Given the address of a particular element in the array, the dsPIC hardware automatically computes the address of the next element in the bit-reversed sequence.
How many twiddle factors are required for computing 32 point FFT?
For example, to compute the twiddle angle factors for the fifth andsixth butterflies in the third stage of a 32-point FFT, we can assign N= 32, Sstart = 3, Sstop = 3, Bstart = 5, and Bstop = 6, and run the code.
