Bit-reversal permutation code

1. What is bit-reversal in FFT?
2. How is bit reverse addressing used in FFT computations?
3. How do you reverse the bit of a number in Java?

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 do you reverse the bit of a number in Java?

The java. lang. Integer. reverse() method returns the value obtained by reversing the order of the bits in the two's complement binary representation of the specified int value.