Paper Info
Title
Broadcast in MIMO Systems Based on a Generalized QR Decomposition: Signaling and Performance Analysis
Abstract
A simple signaling method for broadcast channels with multiple-transmit multiple-receive antennas is proposed. In this method, for each user, the direction in which the user has the maximum gain is determined. The best user in terms of the largest gain is selected. The corresponding direction is used as the modulation vector (MV) for the data stream transmitted to the selected user. The algorithm proceeds in a recursive manner where in each step, the search for the best direction is performed in the null space of the previously selected MVs. It is demonstrated that with the proposed method, each selected MV has no interference on the previously selected MVs. Dirty-paper coding is used to cancel the remaining interference. For the case that each receiver has one antenna, the presented scheme coincides with the known scheme based on Gram-Schmidt orthogonalization (QR decomposition). To analyze the performance of the scheme, an upper bound on the cumulative distribution function (CDF) of each subchannel is derived which is used to establish the diversity order and the asymptotic sum-rate of the scheme. It is shown that using fixed rate codebooks, the diversity order of the jth data stream, 1 les j les M, is equal to N(M - j + 1)(K - j + 1), where M, N, and K indicate the number of transmit antennas, the number of receive antennas, and the number of users, respectively. Furthermore, it is proven that the throughput of this scheme scales as M log log(K) and asymptotically (K rarr infin) tends to the sum-capacity of the multiple-input multiple-output (MIMO) broadcast channel. The simulation results indicate that the achieved sum-rate is close to the sum-capacity of the underlying broadcast channel.
Year
DOI
Venue
2008
10.1109/TIT.2007.915976
IEEE Transactions on Information Theory
Keywords
Field
DocType
best user,selected mv,m log log,broadcast channel,generalized qr decomposition,k rarr infin,known scheme,diversity order,best direction,performance analysis,mimo systems,selected user,scheme scale,interference cancellation,encoding,interference,throughput,matrix decomposition,qr decomposition,gram schmidt orthogonalization,cumulative distribution function,gain,mimo,distribution functions,upper bound,null space,broadcasting
Discrete mathematics,Dirty paper coding,Code rate,Upper and lower bounds,Control theory,Data stream,Matrix decomposition,Algorithm,MIMO,Space-division multiple access,Mathematics,QR decomposition
Journal
Volume
Issue
ISSN
54
3
0018-9448
Citations 
PageRank 
References 
37
1.46
21
Authors
3
Name
Order
Citations
PageRank
Mohammad-Ali Maddah-Ali11455119.30
M. A. Sadrabadi2371.46
A. K. Khandani329719.65