Title :
OFDM code-division multiplexing in fading channels
Author_Institution :
Inst. of Commun. & Navigation, German Aerosp. Center (DLR), Wessling, Germany
fDate :
8/1/2002 12:00:00 AM
Abstract :
In this paper, orthogonal frequency-division multiplexing-code-division multiplexing (OFDM-CDM) is presented and investigated as alternative to conventional OFDM for high rate data transmission. An additional multipath diversity gain can be obtained with OFDM-CDM by spreading each data symbol in frequency and time. The optimum reliability information for the Viterbi (1979) decoder is derived for OFDM-CDM systems, and the tradeoff between spreading and channel coding in OFDM systems is presented. By using efficient interference cancellation or joint detection techniques, it can be shown that OFDM-CDM outperforms conventional OFDM with respect to bit error rate (BER) performance and bandwidth efficiency.
Keywords :
OFDM modulation; Viterbi decoding; diversity reception; error statistics; fading channels; interference suppression; multipath channels; radiofrequency interference; signal detection; BER performance; OFDM code-division multiplexing; Viterbi decoder; bandwidth efficiency; bit error rate; channel coding; data symbol spreading; fading channels; high rate data transmission; interference cancellation; joint detection; multipath diversity gain; optimum reliability information; orthogonal frequency-division multiplexing; soft interference cancellation; wireless systems; Bit error rate; Code division multiplexing; Data communication; Decoding; Diversity methods; Fading; Frequency diversity; Frequency division multiplexing; OFDM; Viterbi algorithm;
Journal_Title :
Communications, IEEE Transactions on
DOI :
10.1109/TCOMM.2002.801460
