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Since many users share limited wireless resources in wireless networks, it is important for resources to be allocated among users in a fair and efficient manner. The scheduler at the base station is responsible for allocating resources to users. Many researchers have developed efficient scheduling algorithms but most these algorithms were designed separately and independently for the uplink or downlink...
Packet scheduling in wireless network is one of the issues that requires attention to quality of service provision (QoS). In heterogeneous wireless network, whereby many packets of different QoS are involved, packet scheduling becomes more difficult. This paper presents packet scheduling algorithm that uses earliest deadline first for scheduling constant bit rate packets. We estimate the wireless...
Cellular base stations typically orthogonalize downlink transmissions, although this approach is not always throughput-optimal. Indeed, it can be shown that removing the orthogonality constraint (as in Superposition Coding) can provide significant benefits in some scenarios. Based on this principle, we propose a scheduling algorithm for a two-user downlink that leverages the disparity in their respective...
Simulation results of the OSNR performance of an optical switch/router are presented in this paper. The paper is completed with a cascadability analysis, which takes into account the optical link that joins the nodes, and some results that show the effects of the scheduling algorithm on the optical performance.
The paper deals with a modified version of opportunistic scheduling algorithm that exploits multiuser diversity. It incorporates the proportional fairness scheduling policy with the first-in-first-out (FIFO) policy to obtain a hybrid policy that works well when the channel state information of each mobile user is not necessarily known. In the paper, it is proposed that the channel state information...
In this paper we evaluate a recently proposed multiple-input multiple-output (MIMO) system called the Layered Steered Space-Time Codes (LSSTC). The LSSTC system is evaluated for multi-user environments where scheduling can be used to increase the system capacity by harnessing the multi-user diversity. This evaluation is done by comparing the capacity and the probability of error for several combinations...
In this paper, we focus on the subcarrier allocation in the uplink of long term evolution advanced (LTE-A) system assuming equal power allocation among subcarriers. Our goal is to maximize the priority-sum in the uplink considering the power limitation of User Equipment (UE). For the purpose, the method to determine the reallocated RBs set and the optimization procedures of reallocated RBs are proposed,...
In this paper, we develop an opportunistic spectrum scheduling scheme for cognitive radio networks. In the proposed scheme, the channel status (i.e., whether being occupied by primary users) and the instantaneous channel quality (SNR at the secondary receiver) are assumed to vary fast within a frame which consists of a fixed number of slots. At each scheduling epoch, each secondary user will observe...
Virtual MIMO (VMIMO) in the uplink communication system is a promising technique focused in recent years. It groups two or more user equipments (UEs) with individual antenna to construct a VMIMO channel communicating with a base station (BS) simultaneously in the uplink. In this paper we consider two UEs collaboration (2×2 VMIMO), and propose a novel pairing scheduling based on the SINR threshold...
Long term evolution (LTE) is the next generation wireless system that supports all IP transmission for multimedia services. The quality of service (QoS) requirements of multimedia services are one of the major challenges that need to be addressed by packet scheduling in the LTE system. This paper proposes a new resource allocation technique for real time (RT) video streaming applications in the downlink...
In this study, we consider a scheduling algorithm for a limited feedback opportunistic beamforming (OBF). Our proposal is based on making Transmit OBF codebook vectors controlled by a rotation weight (RW)in order to obtain almost a zero correlation between the OBF codebook vectors used for the selected spatial channels. Accordingly, we meet the performance of OBF based on the feedback of the full...
Given that the co-existence of multimedia applications will be a norm in the future wireless systems, their quality of service (QoS) requirements need to be guaranteed. This has imposed new challenges in the design of packet scheduling algorithms in these systems. To address those challenges, a new packet scheduling algorithm for real time (RT) traffic in downlink third generation partnership project...
4G cellular systems and the IMT Advanced candidates will provide broadband wireless access with QoS. Especially in multihop configurations of these systems the base station controls resources centrally while relays can take over a part of the responsibility on the second hop. To make this work on layer two, scheduling is the most important task. However, many dimensions of the problem lead to much...
An improved scheduling algorithm is proposed for optimizing the sum-rate gain in a multiuser Multiple-Input and Multiple-Output (MU-MIMO) downlink system with limited feedback and Block Diagonalization (BD) precoding. A low bits feedback for user selection is followed by a high bits feedback to improve the system sum-rate capacity. Based on our analysis and the simulation result, it shows that the...
It has been proven that the IEEE 802.16 broadband wireless access (BWA) network is the most preferable next-generation network with the well defined quality of service (QoS) framework. Due to lack of the scheduling algorithm for the guaranteed QoS in the IEEE 802.16 standard, many results for the scheduler of the IEEE 802.16 BWA network have been proposed. However, for the downlink transmission with...
This paper investigates the performance of well known packet scheduling algorithms developed for single carrier wireless systems from a real time video streaming perspective. The performance evaluation is conducted using the downlink third generation partnership project long term evolution (3GPP LTE) system as the simulation platform. This paper contributes to the identification of a suitable packet...
In this paper, we introduce an orthogonalization aided distributed scheduling algorithm for multiuser MIMO broadcast channels (MU-MIMO BC). In this algorithm each mobile station (MS) selects transmission scheme, including beamforming (BF) and spatial multiplexing (SM) according to its channel state and feeds back channel state information (CSI) adaptively. On receiving CSI from each MS, the base station...
A new scheduling algorithm with low complexity for user selection is proposed for a multiuser multiple-input and multiple-output (MU-MIMO) downlink system based on block diagonalization (BD) precoding. The new algorithm provides equivalent system performance evaluated as sum-rate capacity in comparison with other user selection algorithms, such as semiorthogonal user selection (SUS) and capacity-based...
Scheduling algorithms are very important in WiMAX for the efficient use of radio resources. However, the standard does not specify which scheduling algorithm(s) should be used. A scheduling algorithm should take into account the WiMAX QoS classes and service requirements. The scheduling algorithm also has to taken into account other models of the WiMAX system such as power saving and pricing models...
In this paper, three scheduling algorithms are presented for multi-user MIMO precoding based on code book to achieve precoding and multi-user diversity gain in broadcast channel. Randomicity, feedback load and system capacity are considered in the three criteria. The precoding matrices are generated based on the per user unitary and rate control (PU2RC) proposed by Samsung. Theoretical analysis and...
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