Title :
On the capacity of noncoherent wideband MIMO-OFDM systems
Author :
Borgmann, Moritz ; Bölcskei, Helmut
Author_Institution :
Commun. Technol. Lab., Swiss Fed. Inst. of Technol., Zurich
Abstract :
We study the capacity behavior of full-band MIMO-OFDM systems in the absence of channel state information both at the transmitter and the receiver. Based on capacity lower and upper bounds, we quantify the transmission rate penalty due to channel uncertainty as a function of the number of transmit antennas, the number of resolvable taps in the channel, the power delay profile, and the bandwidth. Our analysis reveals that for a given bandwidth and transmit power there is an optimum, capacity-maximizing, number of transmit antennas. Numerical results show that using a large number of transmit antennas in systems employing bandwidths of several GHz (such as in ultrawideband systems) is detrimental from a capacity point of view. Finally, we evaluate the capacity performance of space-frequency unitary codebooks recently introduced in M. Borgmann and H. Bolcskei, (2005)
Keywords :
MIMO systems; OFDM modulation; antenna arrays; broadband networks; channel capacity; radio networks; transmitting antennas; capacity behavior; channel state information; channel uncertainty; full-band MIMO-OFDM systems; noncoherent wideband MIMO-OFDM system capacity; power delay profile; resolvable taps; space-frequency unitary codebooks; transmission rate penalty; transmit antennas; transmit power; ultrawideband systems; Bandwidth; Channel state information; Delay; Fading; MIMO; OFDM; Transmitters; Transmitting antennas; Upper bound; Wideband;
Conference_Titel :
Information Theory, 2005. ISIT 2005. Proceedings. International Symposium on
Conference_Location :
Adelaide, SA
Print_ISBN :
0-7803-9151-9
DOI :
10.1109/ISIT.2005.1523416