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- Ding, Lianghui, et al.
(författare)
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Energy minimization in wireless multihop networks using two-way network coding
- 2011
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Ingår i: IEEE 73rd Vehicular Technology Conference (VTC-2011-Spring), Budapest, Ungern. - 9781424483310
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Konferensbidrag (refereegranskat)abstract
- The total energy minimization in wireless multihop networks using two-way network coding is investigated in this paper. The problem is first formulated as a linear programming problem, then decomposed into two sub-problems using the Lagrangian decomposition, and finally solved with the subgradient method. After that, the backpressure based algorithm is proposed to solve the problem in a distributed manner. The performance of the algorithm is evaluated first in a simple topology for analysis and then in a random topology with different number of flows for practical consideration. Simulation results show that the convergence time increases as the number of nodes in the network, and the energy cost per packet can be saved up to 30% by using two-way network coding.
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| 2. |
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| 3. |
- Ding, Liang-Hui, et al.
(författare)
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Lifetime maximization routing with network coding in wireless multihop networks
- 2013
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Ingår i: SCIENCE CHINA-INFORMATION SCIENCES. - : Springer Science and Business Media LLC. - 1674-733X .- 1869-1919. ; 56:2, s. 1-15
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we consider the lifetime maximization routing with network coding in wireless multihop networks. We first show that lifetime maximization with network coding is different from pure routing, throughput maximization with network coding and energy minimization with network coding. Then we formulate lifetime maximization problems in three different cases of (i) no network coding, (ii) two-way network coding, and (iii) overhearing network coding. To solve these problems, we use flow augmenting routing (FA) for the first case, and then extend the FA with network coding (FANC) by using energy minimized one-hop network coding. After that, we investigate the influence of parameters of FANC, evaluate the performance of FANC with two-way and overhearing network coding schemes and compare it with that without network coding under two different power control models, namely, protocol and physical ones. The results show that the lifetime can be improved significantly by using network coding, and the performance gain of network coding decreases with the increase of flow asymmetry and the power control ability.
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| 4. |
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| 5. |
- Wang, Hao, et al.
(författare)
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A unified algorithm for mobility load balancing in 3GPP LTE multi-cell networks
- 2013
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Ingår i: Science in China. Series F, Information Sciences. - : Science China Press. - 1009-2757. ; 56
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Tidskriftsartikel (refereegranskat)abstract
- 3GPP long term evolution (LTE) is a promising candidate for the next-generation wireless network, which is expected to achieve high spectrum efficiency by using advanced physical layer techniques and flat network structures. However, the LTE network still faces the problem of load imbalance as in GSM/WCDMA networks, and this may cause significant deterioration of system performance. To deal with this problem, mobility load balancing (MLB) has been proposed as an important use case in 3GPP self-organizing network (SON), in which the serving cell of a user can be selected to achieve load balancing rather than act as the cell with the maximum received power. Furthermore, the LTE network aims to serve users with different quality-of-service (QoS) requirements, and the network-wide objective function for load balancing is distinct for different kinds of users. Thus, in this paper, a unified algorithm is proposed for MLB in the LTE network. The load balancing problem is first formulated as an optimization problem with the optimizing variables being cell-user connections. Then the complexity and overhead of the optimal solution is analyzed and a practical and distributed algorithm is given. After that, the proposed algorithm is evaluated for users with different kinds of QoS requirements, i.e., guaranteed bit rate (GBR) users with the objective function of load balance index and non-GBR (nGBR) users with the objective function of total utility, respectively. Simulation results show that the proposed algorithm leads to significantly balanced load distribution for GBR users to decrease the new call blocking rate, and for nGBR users to improve the cell-edge throughput at the cost of only slight deterioration of total throughput.
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| 8. |
- Wang, Hao, et al.
(författare)
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Minimum rate guaranteed call admission control for cumulative rate distribution based scheduling
- 2011
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Ingår i: IEEE Communications Letters. - 1089-7798 .- 1558-2558. ; 15:11, s. 1181-1183
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Tidskriftsartikel (refereegranskat)abstract
- In this letter, we investigate call admission control (CAC) for cumulative rate distribution based scheduling (CS) in wireless communication networks. We first analyze the multi-user diversity gain (MDG) of CS, which is applicable to general channel conditions. Then we propose the minimum rate guaranteed CS/ORR based CAC algorithm, COCAC, which jointly uses CS and opportunistic round robin (ORR) for resource prediction and CAC decision. Furthermore, we evaluate the performance of our COCAC algorithm through simulation. Results show that COCAC can significantly reduce the new call blocking rate, while strictly guarantee the minimum rate requirements of all serving users.
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| 9. |
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| 10. |
- Wang, Hao, et al.
(författare)
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Three novel opportunistic scheduling algorithms in CoMP-CSB scenario
- 2013
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Ingår i: Science China-Information Sciences. - : Springer Science and Business Media LLC. - 1674-733X .- 1869-1919. ; 56:8, s. 082301-
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Tidskriftsartikel (refereegranskat)abstract
- Coordinated scheduling/beamforming (CSB), which belongs to the coordinated multi-point (CoMP) transmission, has received lots of attention recently due to its great potential to mitigate inter-cell interference (ICI) and to increase the cell-edge throughput, and meanwhile it only requires limited base station cooperation and is easy to implement. However, to the best of our knowledge, there are no effective scheduling algorithms with low complexity and overhead in CoMP-CSB scenario as yet. Thus, in this paper, we propose three novel opportunistic scheduling algorithms in CoMP-CSB scenario. All of them jointly consider the intended channel condition of the scheduled user from its serving cell and the orthogonality between the intended channel and the corresponding interference channels to concurrently scheduled users in nearby cells, thus exploiting multi-user diversity (MUD) and mitigating ICI at the same time. Algorithm 1 cooperatively chooses the most orthogonal user pair within a candidate user set in which all users have a large local channel feedback, while Algorithm 2 concurrently schedules the user pair with the largest ratio between the local channel feedbacks and the aforementioned orthogonality within the same candidate user set. Algorithm 3 performs in the way similar to the proportional fairness scheduling, while making a proper modification for its usage in CoMP-CSB scenario. The performance of the proposed scheduling algorithms are evaluated through simulation. Results show that, they all can significantly enhance the received signal to interference plus noise ratio (SINR) with relatively good fairness guarantee, thus achieving larger throughputs and utilities than several well-known scheduling algorithms. Algorithm 2 even outperforms Algorithm 1 when the aforementioned candidate user set is big enough in size and has a bit more overhead/complexity. Furthermore, Algorithms 3 is the best one among all the three proposed algorithms, but it requires more overhead/complexity than Algorithm 1 and 2. Finally, we give the optimal parameter for all of the three proposed algorithms, which can make a good tradeoff between performance and overhead/complexity.
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