Bit reversal in fft

1. What is bit-reversal in FFT algorithm?
2. Why is bit-reversal done in FFT?
3. How is bit reverse addressing used in FFT computations?
4. What is 64 point FFT?

What is bit-reversal in FFT algorithm?

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.

Why is bit-reversal done in FFT?

FFT and IFFT Blocks Data Order

Because linear ordering of the frequency indices requires a bit-reversal operation, the FFT block may run more quickly when the output frequencies are in bit-reversed order. The input to the IFFT block can be in linear or bit-reversed order.

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.

What is 64 point FFT?

The 64-point FFT is realized by decomposing it into a two-dimensional structure of 8-point FFTs. This approach reduces the number of required complex multiplications compared to the conventional radix-2 64-point FFT algorithm. The complex multiplication operations are realized using shift-and-add operations.