OFDM Conventional orthogonal frequency division multiplexing(OFDM) system X(m)- serial to idFT h(n) Parallel X(n) Cyclic Prefix Prefix X(m) Parallel to serial qualizer( +Y(n) detector Removal det ann mator Georgia Institute of Technology Center for Signal and Image Processing
Georgia Institute of Technology Center for Signal and Image Processing • Conventional orthogonal frequency division multiplexing (OFDM) system. OFDM - I Serial to Parallel Parallel to Serial IDFT & Cyclic Prefix Prefix Removal & DFT X(m) X(n) Equalizer & Detector X(m) Channel Estimator Y(n) Tx Rx h(n)
OFDM- Serial to parallel converter collects K serial data symbols X(m)into a data block or vector X(n) X(n)is modulated by an IDFT into OFDM symbol vector x(n) a length G cyclic prefix is added to x(n) and transmitted through a frequency-selective channel h(n)of order L At the receiver, the cyclic prefix is removed from the received signal and the remaining signal is demodulated by an dFT into Y(n) Georgia Institute of Technology Center for Signal and Image Processing
Georgia Institute of Technology Center for Signal and Image Processing OFDM - II • Serial to parallel converter collects K serial data symbols X(m) into a data block or vector X(n). • X(n) is modulated by an IDFT into OFDM symbol vector x(n). • A length G cyclic prefix is added to x(n) and transmitted through a frequency-selective channel h(n) of order L. • At the receiver, the cyclic prefix is removed from the received signal and the remaining signal is demodulated by an DFT into Y(n)