2-dimentional spreading method for ofdm-cdm system

OFDM of the present invention a code division transmitter for multiplexing-based communication system is a frequency spreader, the frequency spread symbols to output a frequency-spread symbols in the number corresponding to the magnitude of the frequency spreading factor is multiplied by the frequency spreading factor in a transmission symbol them to the temporary storage by as much as a predetermined number, by multiplying the time spreading factor in the frequency spread symbols output in parallel from a number of buffers, the buffer corresponding to the size of the frequency spreading factor frequency-outputting time spread symbols time spreader, and the frequency of the parallel output from the time spreader for-transmission by inserting a guard interval to the inverse Fourier transform signal output from the inverse Fourier transformer for outputting an OFDM symbol by performing an inverse fast Fourier transform to the time spreading symbol protection period is configured as a insert. OFDM-CDM system, as well as by the frequency hopping to spread the signal with a two-dimensional spreading in the frequency domain and a time domain transmission signal to obtain the full diversity gain in any channel environment, by mapping to OFDM symbol time-varying channel according to the present invention residual gain by the effect can be obtained. Frequency diversity, time diversity, frequency hopping, orthogonal frequency division multiplexing