6,239 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
Asymptotic Close To Optimal Joint Resource Allocation and Power Control in the Uplink of Two-cell Networks
In this paper, we investigate joint resource allocation and power control
mechanisms for two-cell networks, where each cell has some sub-channels which
should be allocated to some users. The main goal persuaded in the current work
is finding the best power and sub-channel assignment strategies so that the
associated sum-rate of network is maximized, while a minimum rate constraint is
maintained by each user. The underlying optimization problem is a highly
non-convex mixed integer and non-linear problem which does not yield a trivial
solution. In this regard, to tackle the problem, using an approximate function
which is quite tight at moderate to high signal to interference plus noise
ratio (SINR) region, the problem is divided into two disjoint sub-channel
assignment and power allocation problems. It is shown that having fixed the
allocated power of each user, the subchannel assignment can be thought as a
well-known assignment problem which can be effectively solved using the
so-called Hungarian method. Then, the power allocation is analytically derived.
Furthermore, it is shown that the power can be chosen from two extremal points
of the maximum available power or the minimum power satisfying the rate
constraint. Numerical results demonstrate the superiority of the proposed
approach over the random selection strategy as well as the method proposed in
[3] which is regarded as the best known method addressed in the literature
Resource Allocation for Device-to-Device Communications in Multi-Cell Multi-Band Heterogeneous Cellular Networks
Heterogeneous cellular networks (HCNs) with millimeter wave (mm-wave)
communications are considered as a promising technology for the fifth
generation mobile networks. Mm-wave has the potential to provide multiple
gigabit data rate due to the broad spectrum. Unfortunately, additional free
space path loss is also caused by the high carrier frequency. On the other
hand, mm-wave signals are sensitive to obstacles and more vulnerable to
blocking effects. To address this issue, highly directional narrow beams are
utilized in mm-wave networks. Additionally, device-to-device (D2D) users make
full use of their proximity and share uplink spectrum resources in HCNs to
increase the spectrum efficiency and network capacity. Towards the caused
complex interferences, the combination of D2D-enabled HCNs with small cells
densely deployed and mm-wave communications poses a big challenge to the
resource allocation problems. In this paper, we formulate the optimization
problem of D2D communication spectrum resource allocation among multiple
micro-wave bands and multiple mm-wave bands in HCNs. Then, considering the
totally different propagation conditions on the two bands, a heuristic
algorithm is proposed to maximize the system transmission rate and approximate
the solutions with sufficient accuracies. Compared with other practical
schemes, we carry out extensive simulations with different system parameters,
and demonstrate the superior performance of the proposed scheme. In addition,
the optimality and complexity are simulated to further verify effectiveness and
efficiency.Comment: 13 pages, 11 figures, IEEE Transactions on Vehicular Technolog
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