Multiplexer-demultiplexer for synthesising or analysing frequency multiplex signals in multi-carrier system - has common filter block and real and imaginary part blocks for inverse discrete fast Fourier transformation

摘要

In the demultiplexing arrangement, the arising complex-valued input signal - in the form of two independent, time-dependent signal sequences, real-part Sr(KT), and imaginary part, Si(KT) - undergoes a scanning rate halving (fA/2). The real-part unit imaginary part of the input signal are then displaced by T/2 and processed in a central unit (BC). Its output signals (Vi') and (1r) are then combined with the other output signals (V0r) out of component module (B1) and V2i) out of module (B2) of the upper branch as well as (V0i) out of B1 and (-V2r) out of B2 of the lower branch, in an inverse discrete or fast Fourier transform (1FFT) to form two complex valued output signals SD(KT)=S0r+jsoi and S1(KT)=s1r+js1i. USE - Satellite communications.