5,473 research outputs found
On the Throughput of Large-but-Finite MIMO Networks using Schedulers
This paper studies the sum throughput of the {multi-user}
multiple-input-single-output (MISO) networks in the cases with large but finite
number of transmit antennas and users. Considering continuous and bursty
communication scenarios with different users' data request probabilities, we
derive quasi-closed-form expressions for the maximum achievable throughput of
the networks using optimal schedulers. The results are obtained in various
cases with different levels of interference cancellation. Also, we develop an
efficient scheduling scheme using genetic algorithms (GAs), and evaluate the
effect of different parameters, such as channel/precoding models, number of
antennas/users, scheduling costs and power amplifiers' efficiency, on the
system performance. Finally, we use the recent results on the achievable rates
of finite block-length codes to analyze the system performance in the cases
with short packets. As demonstrated, the proposed GA-based scheduler reaches
(almost) the same throughput as in the exhaustive search-based optimal
scheduler, with substantially less implementation complexity. Moreover, the
power amplifiers' inefficiency and the scheduling delay affect the performance
of the scheduling-based systems significantly
Joint User Scheduling and Power optimization in Full-Duplex Cells with Successive Interference Cancellation
This paper considers a cellular system with a full-duplex base station and
half-duplex users. The base station can activate one user in uplink or downlink
(half-duplex mode), or two different users one in each direction simultaneously
(full-duplex mode). Simultaneous transmissions in uplink and downlink causes
self-interference at the base station and uplink-to-downlink interference at
the downlink user. Although uplink-to-downlink interference is typically
treated as noise, it is shown that successive interference decoding and
cancellation (SIC mode) can lead to significant improvement in network utility,
especially when user distribution is concentrated around a few hotspots. The
proposed temporal fair user scheduling algorithm and corresponding power
optimization utilizes full-duplex and SIC modes as well as half-duplex
transmissions based on their impact on network utility. Simulation results
reveal that the proposed strategy can achieve up to 95% average cell throughput
improvement in typical indoor scenarios with respect to a conventional network
in which the base station is half-duplex.Comment: To be appeared in IEEE Asilomar Conference on Signals, Systems, and
Computers, 201
Spectral Efficiency Scaling Laws in Dense Random Wireless Networks with Multiple Receive Antennas
This paper considers large random wireless networks where
transmit-and-receive node pairs communicate within a certain range while
sharing a common spectrum. By modeling the spatial locations of nodes based on
stochastic geometry, analytical expressions for the ergodic spectral efficiency
of a typical node pair are derived as a function of the channel state
information available at a receiver (CSIR) in terms of relevant system
parameters: the density of communication links, the number of receive antennas,
the path loss exponent, and the operating signal-to-noise ratio. One key
finding is that when the receiver only exploits CSIR for the direct link, the
sum of spectral efficiencies linearly improves as the density increases, when
the number of receive antennas increases as a certain super-linear function of
the density. When each receiver exploits CSIR for a set of dominant interfering
links in addition to the direct link, the sum of spectral efficiencies linearly
increases with both the density and the path loss exponent if the number of
antennas is a linear function of the density. This observation demonstrates
that having CSIR for dominant interfering links provides a multiplicative gain
in the scaling law. It is also shown that this linear scaling holds for direct
CSIR when incorporating the effect of the receive antenna correlation, provided
that the rank of the spatial correlation matrix scales super-linearly with the
density. Simulation results back scaling laws derived from stochastic geometry.Comment: Submitte
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