Bit reverse order Technique in FFT

1. What do you mean by bit reversal technique in FFT?
2. Why do we use bit reversal in FFT?
3. How is bit reverse addressing used in FFT computations?
4. What are different types of FFT in DSP?

What do you mean by bit reversal technique in FFT?

“Bit reversal” is just what it sounds like: reversing the bits in a binary word from left to right. Therefore the MSBs become LSBs and the LSBs become MSBs.

Why do we use bit reversal in FFT?

The FFT block enables you to output the frequency indices in linear or bit-reversed 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.

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 are different types of FFT in DSP?

Two different procedures are introduced to compute an FFT: the decimation-in-frequency and the decimation-in-time. Several variants of the FFT have been used, such as the Winograd transform [7, 8], the discrete cosine transform (DCT) [9], and the discrete Hartley transform [10–12].