198 research outputs found
Performance of Uplink Multiuser Massive MIMO Systems
We study the performance of uplink transmission in a large-scale (massive)
MIMO system, where all the transmitters have single antennas and the receiver
(base station) has a large number of antennas. Specifically, we analyze
achievable degrees of freedom of the system without assuming channel state
information at the receiver. Also, we quantify the amount of power saving that
is possible with increasing number of receive antennas.Comment: 5 pages, no figur
Joint Optimization of Power Allocation and Training Duration for Uplink Multiuser MIMO Communications
In this paper, we consider a multiuser multiple-input multiple-output
(MU-MIMO) communication system between a base station equipped with multiple
antennas and multiple mobile users each equipped with a single antenna. The
uplink scenario is considered. The uplink channels are acquired by the base
station through a training phase. Two linear processing schemes are considered,
namely maximum-ratio combining (MRC) and zero-forcing (ZF). We optimize the
training period and optimal training energy under the average and peak power
constraint so that an achievable sum rate is maximized.Comment: Submitted to WCN
Multiple-Antenna Interference Channel with Receive Antenna Joint Processing and Real Interference Alignment
We consider a constant -user Gaussian interference channel with
antennas at each transmitter and antennas at each receiver, denoted as a
channel. Relying on a result on simultaneous Diophantine
approximation, a real interference alignment scheme with joint receive antenna
processing is developed. The scheme is used to provide new proofs for two
previously known results, namely 1) the total degrees of freedom (DoF) of a
channel is ; and 2) the total DoF of a channel is
at least . We also derive the DoF region of the channel,
and an inner bound on the DoF region of the channel
A Nonconvex Splitting Method for Symmetric Nonnegative Matrix Factorization: Convergence Analysis and Optimality
Symmetric nonnegative matrix factorization (SymNMF) has important
applications in data analytics problems such as document clustering, community
detection and image segmentation. In this paper, we propose a novel nonconvex
variable splitting method for solving SymNMF. The proposed algorithm is
guaranteed to converge to the set of Karush-Kuhn-Tucker (KKT) points of the
nonconvex SymNMF problem. Furthermore, it achieves a global sublinear
convergence rate. We also show that the algorithm can be efficiently
implemented in parallel. Further, sufficient conditions are provided which
guarantee the global and local optimality of the obtained solutions. Extensive
numerical results performed on both synthetic and real data sets suggest that
the proposed algorithm converges quickly to a local minimum solution.Comment: IEEE Transactions on Signal Processing (to appear
- …