5,957 research outputs found
Joint Multi-Cell Resource Allocation Using Pure Binary-Integer Programming for LTE Uplink
Due to high system capacity requirement, 3GPP Long Term Evolution (LTE) is
likely to adopt frequency reuse factor 1 at the cost of suffering severe
inter-cell interference (ICI). One of combating ICI strategies is network
cooperation of resource allocation (RA). For LTE uplink RA, requiring all the
subcarriers to be allocated adjacently complicates the RA problem greatly. This
paper investigates the joint multi-cell RA problem for LTE uplink. We model the
uplink RA and ICI mitigation problem using pure binary-integer programming
(BIP), with integrative consideration of all users' channel state information
(CSI). The advantage of the pure BIP model is that it can be solved by
branch-and-bound search (BBS) algorithm or other BIP solving algorithms, rather
than resorting to exhaustive search. The system-level simulation results show
that it yields 14.83% and 22.13% gains over single-cell optimal RA in average
spectrum efficiency and 5th percentile of user throughput, respectively.Comment: Accepted to IEEE Vehicular Technology Conference (VTC Spring), Seoul,
Korea, May, 201
Opportunistic Scheduling for Full-Duplex Uplink-Downlink Networks
We study opportunistic scheduling and the sum capacity of cellular networks
with a full-duplex multi-antenna base station and a large number of
single-antenna half-duplex users. Simultaneous uplink and downlink over the
same band results in uplink-to-downlink interference, degrading performance. We
present a simple opportunistic joint uplink-downlink scheduling algorithm that
exploits multiuser diversity and treats interference as noise. We show that in
homogeneous networks, our algorithm achieves the same sum capacity as what
would have been achieved if there was no uplink-to-downlink interference,
asymptotically in the number of users. The algorithm does not require
interference CSI at the base station or uplink users. It is also shown that for
a simple class of heterogeneous networks without sufficient channel diversity,
it is not possible to achieve the corresponding interference-free system
capacity. We discuss the potential for using device-to-device side-channels to
overcome this limitation in heterogeneous networks.Comment: 10 pages, 2 figures, to appear at IEEE International Symposium on
Information Theory (ISIT) '1
Analysis of packet scheduling for UMTS EUL - design decisions and performance evaluation
The UMTS Enhanced Uplink (EUL) provides higher capacity, increased data rates and smaller latency on the communication link from users towards the network. In this paper we present a performance comparison of three distinct EUL scheduling schemes (one-by-one, partial parallel and full parallel) taking into account both the packet level characteristics and the flow level dynamics due to the (random) user behaviour.\ud
Using a very efficient hybrid analytical and simulation approach we analyse the three schemes with respect to performance measures such as mean file transfer time and fairness. In UMTS, a significant part of the system capacity will be used to support non-elastic voice traffic. Hence, part of our investigation is dedicated to the effects that the volume of voice traffic has on the performance of the elastic traffic supported by the EUL. Finally, we evaluate the impact that implementation specifics of a full parallel scheduler has on these measures.\ud
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Our main conclusion is that our partial parallel scheduler, which is a hybrid between the one-by-one and full parallel, outperforms the other two schedulers in terms of mean flow transfer time, and is less sensitive to volume and nature of voice traffic. However, under certain circumstances, the partial parallel scheduler exhibits a somewhat lower fairness than the alternatives
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