Computer Science – Information Theory
Scientific paper
2005-12-12
Computer Science
Information Theory
submitted to IEEE Trans. Information Theory Jan. 2004; current version addresses referees' minor comments; 13 pages
Scientific paper
Differential Unitary Space-Time Modulation (DUSTM) and its earlier nondifferential counterpart, USTM, permit high-throughput MIMO communication entirely without the possession of channel state information (CSI) by either the transmitter or the receiver. For an isotropically random unitary input we obtain the exact closed-form expression for the probability density of the DUSTM received signal, which permits the straightforward Monte Carlo evaluation of its mutual information. We compare the performance of DUSTM and USTM through both numerical computations of mutual information and through the analysis of low- and high-SNR asymptotic expressions. In our comparisons the symbol durations of the equivalent unitary space-time signals are both equal to T, as are the number of receive antennas N. For DUSTM the number of transmit antennas is constrained by the scheme to be M = T/2, while USTM has no such constraint. If DUSTM and USTM utilize the same number of transmit antennas at high SNR's the normalized mutual information of the differential and the nondifferential schemes expressed in bits/sec/Hz are asymptotically equal, with the differential scheme performing somewhat better, while at low SNR's the normalized mutual information of DUSTM is asymptotically twice the normalized mutual information of USTM. If, instead, USTM utilizes the optimum number of transmit antennas then USTM can outperform DUSTM at sufficiently low SNR's.
Marzetta Thomas L.
Moustakas Aris L.
Simon Steven H.
No associations
LandOfFree
Capacity of Differential versus Non-Differential Unitary Space-Time Modulation for MIMO channels does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Capacity of Differential versus Non-Differential Unitary Space-Time Modulation for MIMO channels, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Capacity of Differential versus Non-Differential Unitary Space-Time Modulation for MIMO channels will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-502551