Title :
Characteristics of OFDM/CDMA System Using Frequency and Time Domain Spreading
Author :
Tachikawa, Shin´ichi ; Ueki, Takahisa
Author_Institution :
Nagaoka Univ. of Technol., Nagaoka-Shi
Abstract :
This paper presents BER performances of OFDM/CDMA using combined frequency and time domain spreading (abbreviated as FT-CDMA). In the system, we employ a different frequency interleaver for each user and adaptive filters to suppress multiple access interference in an asynchronous multiple access system. In conventional MC-CDMA and MC-DS/CDMA systems, the improvement of BER performance can be obtained from only frequency or time domain however, in the FT-CDMA, it can be obtained from both domains. The performance are evaluated in a multi-path fading channel (a close 6-path model). As a result of computer simulations, it is shown BER performance of FT-CDMA is superior to that of the others in the channel
Keywords :
OFDM modulation; adaptive filters; code division multiple access; error statistics; fading channels; interference suppression; multipath channels; radiofrequency interference; time-frequency analysis; BER; FT-CDMA; OFDM system; adaptive filter; asynchronous multiple access system; bit error rate; code division multiple access; frequency interleaver; frequency-time domain spreading; multipath fading channel; multiple access interference suppression; orthogonal frequency division multiplexing; Adaptive filters; Bit error rate; Fading; Frequency domain analysis; Multiaccess communication; Multicarrier code division multiple access; Multiple access interference; OFDM; Performance evaluation; Transmitters; OFDM/CDMA; adaptive filter; frequency and time domain spreading; frequency interleaver; multi-path fading channel;
Conference_Titel :
Spread Spectrum Techniques and Applications, 2006 IEEE Ninth International Symposium on
Conference_Location :
Manaus-Amazon
Print_ISBN :
0-7803-9779-7
Electronic_ISBN :
0-7803-9780-0
DOI :
10.1109/ISSSTA.2006.311752
