Title :
A time spreaded quasi-orthogonal space-frequency coded scheme for OFDM systems
Author :
Senthuran, Sivasothy ; Anpalagan, Alagan ; Das, Olivia
Author_Institution :
Dept. of Electr. & Comput. Eng., Ryerson Univ., Toronto, ON
Abstract :
A space-frequency (SF) coded orthogonal frequency division multiplexing (OFDM) system performs well in fast fading channels. The Hadamard time spreading offers additional time diversity gain with low complexity to SF-OFDM systems. Since quasi-orthogonal codes give higher data rate as compared to the orthogonal codes, this paper proposes a time spreaded quasi-orthogonal SF-OFDM system (called T-QOSF-OFDM) to achieve higher data rates with robust performance in fast fading channels. The proposed system performance is analyzed for different maximum Doppler frequency (fd) and time block spreading factor (M) via Monte-Carlo simulation. The T-QOSF-OFDM with 4 transmitter and 1 receiver antenna configuration offers 2 dB gain over orthogonal SF-OFDM system for fd = 300 Hz and M = 64 at BER of 10-4.
Keywords :
OFDM modulation; diversity reception; error statistics; fading channels; orthogonal codes; BER; Doppler frequency; Hadamard time spreading; Monte-Carlo simulation; SF-OFDM systems; T-QOSF-OFDM; fast fading channels; frequency 300 Hz; gain 2 dB; space-frequency coded orthogonal frequency division multiplexing system; time block spreading factor; time diversity gain; time spreaded quasiorthogonal space-frequency coded scheme; Diversity methods; Fading; Gain; OFDM; Performance analysis; Receiving antennas; Robustness; System performance; Transmitters; Transmitting antennas;
Conference_Titel :
Communications, 2008 24th Biennial Symposium on
Conference_Location :
Kingston, ON
Print_ISBN :
978-1-4244-1945-6
Electronic_ISBN :
978-1-4244-1946-3
DOI :
10.1109/BSC.2008.4563234
