Title :
A novel time spreading method for down-link OFDM-code division multiplexing systems
Author :
Cho, Myeongyun ; Cho, Hangyu ; Ro, Sangmin ; Hong, Daesik
Author_Institution :
I-Networking Lab, Samsung Adv. Inst. of Technol., Suwon, South Korea
Abstract :
Orthogonal frequency division multiplexing code division multiplexing (OFDM-CDM) using a novel time spreading scheme is proposed as an alternative to multicarrier code division multiple access (MC-CDMA) systems. A residual frequency diversity gain can he fully obtained with OFDM-CDM through the adaptation of the proposed time spreading scheme which has a known frequency-hopping pattern over the whole transmission bandwidth. If there is enough frequency space to hop and the space is larger than the coherent bandwidth of the channel, we can exploit full frequency diversity in any channel environment. Simulation results verify that the proposed method achieves a gain of about 4 dB for BER of 10-3 compared to the conventional OFDM-CDM, which achieves a similar performance as frequency-interleaved MC-CDMA.
Keywords :
OFDM modulation; code division multiplexing; diversity reception; frequency hop communication; mobile radio; spread spectrum communication; BER; MC-CDMA; OFDM-CDM system downlink; channel coherent bandwidth; code division multiplexing; frequency-hopping pattern; mobile radio systems; multicarrier code division multiple access; orthogonal frequency division multiplexing; residual frequency diversity gain; spread-spectrum technique; time spreading method; Bandwidth; Bit error rate; Cities and towns; Code division multiplexing; Frequency diversity; Information technology; Modulation coding; Multicarrier code division multiple access; OFDM; Transmitters;
Conference_Titel :
Vehicular Technology Conference, 2004. VTC2004-Fall. 2004 IEEE 60th
Print_ISBN :
0-7803-8521-7
DOI :
10.1109/VETECF.2004.1400356
