Stage of the Fourier transform fast decimau00e7u00e3o frequency, fast Fourier transform processor, receiver of orthogonal frequency division multiplexer and method for performing a fast Fourier transform of the frequency decimau00e7u00e3o

摘要

Stage of the Fourier transform in frequency decimau00e7u00e3o fast Fourier transform processor quickly, receiver of orthogonal frequency division multiplexer and method for performing a Fourier transform fast decimau00e7u00e3o in frequency. A stage of FFT dif FFT is used in a segment n, where n is an integer pair.The stage of FFT dif includes logic chip that receives a first input sample x (V), and a second sample input, X (V + n / 2)And selectively supplies or the first and the second input samples in the respective first and second output ports of the logic of exchange, or alternatively the second and the first samples of entry in the respective first and second output ports of the logic of exchange, where 0 V sym... N / 2.The stage of FFT dif also includes a summation unit to add values provided by the first and second door desau00edda logic of exchange, a unit of differentiation to subtract values provided by the first and second exit door of the logic chip; and the logic of fat Or rotation which multiplies a value provided by the unit of differentiation by a rotation factor.W ~ n ~ ^ (V + s) mod / N / 2) ^, where s is an integer representing a quantity of displacement circular n samples of entry.