Title :
Spatial transmit diversity techniques for broadband OFDM systems
Author_Institution :
Inst. for Commun. & Navigation, German Aerosp. Center (DLR), Oberpfaffenhofen, Germany
Abstract :
In this paper, we investigate different spatial transmit diversity concepts for orthogonal frequency division multiplexing (OFDM) systems. The idea is to artificially increase the frequency and time selectivity of the resulting channel transfer function at the receiver antenna by specific time-variant phase rotations of the signal at the transmit antennas. The achievable performance gains with the proposed transmit diversity concepts are presented for convolutionally coded OFDM systems in typical indoor and outdoor environments. The new concepts can be implemented in already standardized and existing OFDM systems like DAB and DVB-T or HIPERLAN/2, IEEE 802.11 and MMAC, without changing the standards and the receivers. Moreover, we show further performance improvements by combining the spatial transmit diversity concepts for OFDM with code division multiplexing (CDM)
Keywords :
OFDM modulation; broadband networks; indoor radio; land mobile radio; receiving antennas; transfer functions; transmitting antennas; DAB; DVB-T; HIPERLAN/2; IEEE 802.11; MMAC; broadband OFDM systems; channel transfer function; code division multiplexing; convolutionally coded OFDM system; frequency selectivity; indoor environment; orthogonal frequency division multiplexing; outdoor environment; performance gains; receiver antenna; spatial transmit diversity techniques; time selectivity; time-variant phase rotations; Code division multiplexing; Convolution; Convolutional codes; Digital video broadcasting; Diversity reception; OFDM; Performance gain; Receiving antennas; Transfer functions; Transmitting antennas;
Conference_Titel :
Global Telecommunications Conference, 2000. GLOBECOM '00. IEEE
Conference_Location :
San Francisco, CA
Print_ISBN :
0-7803-6451-1
DOI :
10.1109/GLOCOM.2000.891949
