This paper considers an interference-aware user selection and resource allocation for uplink multiuser multiple-input multiple-output (MU-MIMO) systems. At the base station (BS), zero-forcing (ZF) with singular value ...
详细信息
ISBN:
(纸本)9781479965601
This paper considers an interference-aware user selection and resource allocation for uplink multiuser multiple-input multiple-output (MU-MIMO) systems. At the base station (BS), zero-forcing (ZF) with singular value decomposition (SVD) decoupling of spatial streams is deployed. First, two algorithms are developed for mobile stations (MS)s and their corresponding antennas assignment as well as power allocation. The objective is to maximize the total system sum rate by considering the impact of multiple access noise enhancement on the spatial stream capacity. Then, an additional scheme is proposed to maximize the weighted sum capacity of all admitted users, where the weights are chosen based on the state of users' buffers. The proposed resource allocation and scheduling algorithms operate in a reduced search space for the sub-optimum configurations targeting lower overall complexity but still offering close to optimum results in a statistical sense. Simulation results are provided to demonstrate the potential of the developed technique in terms of total system sum rate performance and the buffer behavior.
Time-shiftable loads, also known as deferrable loads, such as charging of electric vehicles, washing machines, dryers, are able to provide scheduling flexibility for demand response. This can help to reduce the energy...
详细信息
ISBN:
(纸本)9781509012374
Time-shiftable loads, also known as deferrable loads, such as charging of electric vehicles, washing machines, dryers, are able to provide scheduling flexibility for demand response. This can help to reduce the energy cost under the condition of dynamic electricity pricing. It can also facilitate deeper integration of renewable generation by absorbing variability. According to the environmental conditions and real time market price of electricity in Singapore, two real-time price-based scheduling algorithms are proposed and studied in this paper. Simulations were conducted with different percentages of deferrable loads and solar penetration levels, with about 1 million devices participating in the demand side management program. The results show that the proposed algorithms schedule tasks resulting in a significant reduction in electricity bill cost. The algorithm was further modified to include demand and renewable generation forecasts to mitigate the problem of variability, which resulted in deeper possible renewable penetration and better system stability.
Virtual Clock algorithm (VC) is a traffic control algorithm that monitors the average transmission rate of packet data flow. The features of VC include guaranteed throughput, low queuing delay and firewall protection ...
详细信息
Virtual Clock algorithm (VC) is a traffic control algorithm that monitors the average transmission rate of packet data flow. The features of VC include guaranteed throughput, low queuing delay and firewall protection among flows. VC does not provide fairness for dynamic buffer allocation when different categories of flows are to be scheduled. Hence modification is necessary in VC to provide fair share of allocation for various flows. In this paper a modification to VC has been carried out, with a fair share of bandwidth allocation for three applications such as Video, CBR and Audio. The simulation was carried out in C++ based software platform and the performance parameters like delay, throughput and packet loss ratio are calculated and analyzed.
A key mechanism in the LTE traffic processing is the packet scheduler which is in charge of allocating radio resources to User Equipment (UE) based on scheduling schemes involved in the LTE base station. The main cont...
详细信息
ISBN:
(纸本)9781479917754
A key mechanism in the LTE traffic processing is the packet scheduler which is in charge of allocating radio resources to User Equipment (UE) based on scheduling schemes involved in the LTE base station. The main contribution of this work is to propose a new scheduling algorithm for Long Term Evolution (LTE) system. The proposed scheduler satisfies the quality of service (QoS) requirements of the real-time traffic. Simulation results shows that the proposed scheduler can ameliorate the performance on the used metrics among services. The performance evaluation is compared in terms of packet loss ratio (PLR), average throughput and cell spectral efficiency.
Despite distributed in computation and data storage, current data-parallel computing systems are centralized in task scheduling, which results in hierarchies that create single point of failure, limit scalability, and...
详细信息
ISBN:
(纸本)9781509018246
Despite distributed in computation and data storage, current data-parallel computing systems are centralized in task scheduling, which results in hierarchies that create single point of failure, limit scalability, and increase administration costs. In this paper, we propose a fully decentralized scheduling algorithm for data-parallel computing systems on peer-topeer (P2P) networks. Our scheduling algorithm eliminates the centralized scheduler by letting each node in the network make scheduling decisions. To achieve good performance, data locality, which stresses the efficiency of colocating tasks with their input data, and load-balancing, should be considered jointly, and in a decentralized fashion. By exploring a backpressure-based approach, the proposed task scheduling algorithm strikes the right balance between data locality and load-balancing with each node only knowing the status information of part of the nodes in the network, and proves to maximize the throughput.
In real-time embedded systems, scheduling policy is considered one of the main factors that affect their performance. It helps to choose which task should be selected first from ready queue to run. Round Robin (RR) sc...
详细信息
ISBN:
(纸本)9781509002757
In real-time embedded systems, scheduling policy is considered one of the main factors that affect their performance. It helps to choose which task should be selected first from ready queue to run. Round Robin (RR) scheduling algorithm is widely used and its performance highly depends on a Quantum size Qt, which is a predefined amount of time assigned by CPU to every task to be executed. However, the performance degrades with respect to an average waiting time (A WT), an average TurnAround time (ATT) and a number of Context Switches (NCS). This paper presents a new improved dynamic Round Robin scheduling algorithm to reduce the average waiting time, turnaround time and the number of context switches in order to improve the system overall performance. It also presents a comparative analysis between several existing Round Robin algorithms based on the average time for waiting and turn-around and number of context switches.
We study an uplink multi secondary user (SU) system having statistical delay constraints, and an average interference constraint to the primary user (PU). SUs with heterogeneous interference channel statistics, to the...
详细信息
ISBN:
(纸本)9781467385763
We study an uplink multi secondary user (SU) system having statistical delay constraints, and an average interference constraint to the primary user (PU). SUs with heterogeneous interference channel statistics, to the PU, experience heterogeneous delay performances since SUs causing low interference are scheduled more frequently than those causing high interference. We propose a scheduling algorithm that can provide arbitrary average delay guarantees to SUs irrespective of their statistical channel qualities. We derive the algorithm using the Lyapunov technique and show that it yields bounded queues and satisfy the interference constraints. Using simulations, we show its superiority over the Max-Weight algorithm.
One of important classes of computational problems is the class of problem-oriented workflow applications executed in distributed computing environment. The problem-oriented workflow application can be represented by ...
详细信息
ISBN:
(纸本)9789532330854
One of important classes of computational problems is the class of problem-oriented workflow applications executed in distributed computing environment. The problem-oriented workflow application can be represented by the oriented graph with the tasks as the nodes and the data flows as the edges. For the problem-oriented workflow application, we can predict the execution time of the task and the amount of data to be transferred between the tasks. Nowadays, the significant number of scheduling algorithms for the distributed computing environment are proposed. Some of them (like DSC algorithm) take into account the peculiarity of problem-oriented workflow applications. Others (like Min-min algorithm) take into account the many core structure of the node of computational network. However, no one of them take into account both these properties. We developed the new Problem-Oriented scheduling (POS) algorithm for distributed cluster computing environment, which is able to plan the launch of a task on several processor cores, taking into account the limit of task scalability.
Efficiently exploiting multicore processors for real-time applications is challenging because jobs that run concurrently on different cores can interfere on shared resources, severely complicating precise timing analy...
详细信息
ISBN:
(纸本)9781467395076
Efficiently exploiting multicore processors for real-time applications is challenging because jobs that run concurrently on different cores can interfere on shared resources, severely complicating precise timing analysis. We propose a new scheduling model called Isolation scheduling (IS);IS provides a framework to exploiting multicores for real-time applications where tasks are grouped in classes. IS enforces mutually exclusive execution among different task classes, thus avoiding inter-class interference by construction. We show that IS encompasses several recent advances in real-time scheduling as special cases and we propose global and partitioned scheduling algorithms based on this model. Specific results are provided if the task classes correspond to different safety criticality levels.
CPU performance critically depends upon efficiency of the scheduling algorithm. algorithms like Round Robin (RR) and Shortest Job First (SJF) have shortcomings in some circumstances and are dedicated to a particular s...
详细信息
ISBN:
(纸本)9781467382274
CPU performance critically depends upon efficiency of the scheduling algorithm. algorithms like Round Robin (RR) and Shortest Job First (SJF) have shortcomings in some circumstances and are dedicated to a particular scheduling scenario like Round Robin compromises on the reduction of waiting time and SJF compromises on the reduction of response time. This article proposes a new modulus based Round Robin scheduling algorithm that simultaneously offers the least compromise on the reduction of waiting time, number of context switches and response time and discusses it in detail. This article also verifies the results through numerous numerical examples. This article also provides a comparison between the proposed algorithm and the median based and average based scheduling algorithms by discussing the effect of each algorithm over the trend of waiting time, response time and number of context switches numerically and empirically.
暂无评论