The Experts below are selected from a list of 22623 Experts worldwide ranked by ideXlab platform
Preben Mogensen - One of the best experts on this subject based on the ideXlab platform.
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efficient low complexity Packet Scheduling algorithm for mixed urllc and embb traffic in 5g
Vehicular Technology Conference, 2019Co-Authors: Ali Karimi, Nurul Huda Mahmood, Guillermo Pocovi, Klaus I. Pedersen, Preben MogensenAbstract:We address the problem of resource allocation and Packet Scheduling for a mixture of ultra- reliable low-latency communication (URLLC) and enhanced mobile broadband (eMBB) traffic in a fifth generation New Radio (5G NR) networks. A novel resource allocation method is presented that is latency, control channel, hybrid automatic repeat request (HARQ), and radio channel aware in determining the transmission resources for different users. This is of high importance for the Scheduling of URLLC users in order to minimize their latency, avoid unnecessary costly segmentation of URLLC payloads over multiple transmissions, and benefit from radio channel aware multi-user diversity mechanisms. The performance of the proposed algorithm is evaluated with an advanced 5G NR compliant system level simulator with a high degree of realism. Simulation results show promising gains of up to 98% latency improvement for URLLC traffic and 12% eMBB end-user throughput enhancement as compared to conventional proportional fair Scheduling.
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carrier load balancing and Packet Scheduling for multi carrier systems
IEEE Transactions on Wireless Communications, 2010Co-Authors: Yuanye Wang, Klaus I. Pedersen, Troels B Sorensen, Preben MogensenAbstract:Abstract-In this paper we focus on resource allocation for next generation wireless communication systems with aggregation of multiple Component Carriers (CCs), i.e., how to assign the CCs to each user, and how to multiplex multiple users in each CC. We first investigate two carrier load balancing methods for allocating the CCs to the users- Round Robin (RR) and Mobile Hashing (MH) balancing by means of a simple theoretical formulation, as well as system level simulations. At Layer-2 we propose a simple cross-CC Packet Scheduling algorithm that improves the coverage performance and the resource allocation fairness among users, as compared to independent Scheduling per CC. The Long Term Evolution (LTE)-Advanced is selected for the case study of a multi-carrier system. In such a system, RR provides better performance than MH balancing, and the proposed simple Scheduling algorithm is shown to be effective in providing up to 90% coverage gain with no loss of the overall cell throughput, as compared to independent Scheduling per CC.
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adaptive transmission bandwidth based Packet Scheduling for lte uplink
Vehicular Technology Conference, 2008Co-Authors: F D Calabrese, Klaus I. Pedersen, Claudio Rosa, M Anas, Per Henrik Michaelsen, Preben MogensenAbstract:UTRAN long term evolution is currently under standardization within 3GPP with the aim of providing a spectral efficiency 2 to 4 times higher than its predecessor HSUPA/HSDPA release 6. Single carrier FDMA has been selected as multiple access for the uplink. This technology requires the subcarriers allocated to a single user to be adjacent. The consequence is a reduced allocation flexibility which makes it challenging to design effective Packet Scheduling algorithms. This paper proposes a channel aware Packet Scheduling algorithm which exploits the bandwidth flexibility offered by the system to perform an allocation which closely resembles the frequency domain envelope of the metric to be optimized. Compared to a fixed bandwidth approach, the proposed algorithm provides a greater flexibility given the inbuilt adaptation to different scenarios and loads, as well as an improvement in term of performance for the Macro 3 case. In this case the uplink capacity is increased by approximately 20% in average cell throughput and 10% in UE outage compared to a fixed bandwidth channel aware approach.
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performance of spatial division multiplexing mimo with frequency domain Packet Scheduling from theory to practice
IEEE Journal on Selected Areas in Communications, 2008Co-Authors: Na Wei, Troels Emil Kolding, A Pokhariyal, Troels B Sorensen, Preben MogensenAbstract:This paper addresses the performance of spatial division multiplexing (SDM) multiple-input multiple-output (MIMO) techniques together with frequency domain Packet Scheduling (FDPS) in both theory and practice. We start with a theoretical analysis under some ideal assumptions to derive the performance bounds of SDM-FDPS. To facilitate the analysis, a unified SINR concept is utilized to make a fair comparison of MIMO schemes with different number of spatial streams. The effect of Packet Scheduling is included in the post-Scheduling SINR distribution using an analytical model. Based on that, the performance bounds are obtained with a more realistic SINR to throughput mapping metric. The system-level performance of SDM-FDPS has been evaluated under practical constraints using detailed simulations based on the UTRAN long term evolution (LTE) downlink cellular system framework. The purpose is to investigate the impact of realistic factors on performance. Results confirm that the combination of SDM and FDPS can increase the spectral efficiency significantly, particularly in a micro-cell scenario, and up to 30%-60% gain is observed over 1times2 with FDPS depending on the traffic models considered. Finally, the more practical simulation results are compared against the theoretical performance bounds. A performance loss is seen in the simulations due to realistic coding/modulation, impact of frequency selectivity, signalling constraints, imperfect channel quality indicator (CQI), etc.
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performance of mimo with frequency domain Packet Scheduling in utran lte downlink
Vehicular Technology Conference, 2007Co-Authors: Na Wei, Troels Emil Kolding, A Pokhariyal, Troels B Sorensen, Preben MogensenAbstract:This paper addresses the performance of spatial division multiplexing (SDM) multiple-input multiple-output (MIMO) techniques together with frequency domain Packet Scheduling (FDPS) based on UTRAN long term evolution (LTE) downlink. Two SDM concepts currently considered in 3GPP are the single-user (SU-) and the multi-user (MU-) MIMO. For MU-MIMO, multiple users can be scheduled on different streams on the same time-frequency resource, while SU-MIMO restricts one time-frequency resource to a single user. Both concepts are analyzed against the 1times2 maximal ratio combining (MRC) case, using the proportional fair (PF) criterion extended to frequency and spatial domains. The realistic finite buffer best effort traffic model is used in the study. Results show that in the macrocell scenario, the combination of FDPS and SDM (SDM-FDPS) without preceding achieves only marginal gain in cell throughput, due to limited SINR dynamic range. The gain is increased to around 20% when precoding is applied. In the micro-cell scenario, the gain of SDM-FDPS over the reference scheme is increased up to 35% with precoding.
Zsehong Tsai - One of the best experts on this subject based on the ideXlab platform.
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an efficient downlink Packet Scheduling algorithm in lte advanced systems with carrier aggregation
Consumer Communications and Networking Conference, 2011Co-Authors: Yaoliang Chung, Lihjong Jang, Zsehong TsaiAbstract:Carrier Aggregation (CA) is one of the promising features to support the much wider bandwidth for Packet transmissions in Long Term Evolution-Advanced (LTE-A) systems. To the best of our knowledge, works regarding the Packet Scheduling algorithm in LTE-A systems with the CA mechanism have not thoroughly been investigated yet till now. In this paper, we therefore aim to design an efficient Packet Scheduling algorithm based on the proportional fair criterion in such environment. We focus on downlink transmissions supporting both Real-Time (RT) and non-RT traffics simultaneously. Simulation results show that performance measures in terms of the system throughput, the mean delay, and the fairness are much better than those of a system in which component carriers are not aggregated but used independently.
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a quantized water filling Packet Scheduling scheme for downlink transmissions in lte advanced systems with carrier aggregation
International Conference on Software Telecommunications and Computer Networks, 2010Co-Authors: Yaoliang Chung, Zsehong TsaiAbstract:Carrier Aggregation (CA) is one of the promising features in Long Term Evolution-Advanced (LTE-A) systems. Till now, works regarding the Packet Scheduling scheme with CA in different frequency bands have not completely been studied and evaluated yet. Thus, the purpose of this work aims to explore such issue and presents an efficient quantized water-filling Packet Scheduling algorithm for high-data-rate nomadic users in such LTE-A systems. An upper bound of the mean Packet delay is derived and simulation results are also obtained. When compared with the mean Packet delay of a system in which component carriers are not aggregated but used independently, the presented scheme is shown to have significant improvement.
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a quantized water filling Packet Scheduling scheme for downlink transmissions in lte advanced systems with carrier aggregation
International Conference on Software Telecommunications and Computer Networks, 2010Co-Authors: Yaoliang Chung, Zsehong TsaiAbstract:Carrier Aggregation (CA) is one of the promising features in Long Term Evolution-Advanced (LTE-A) systems. Till now, works regarding the Packet Scheduling scheme with CA in different frequency bands have not completely been studied and evaluated yet. Thus, the purpose of this work aims to explore such issue and presents an efficient quantized water-filling Packet Scheduling algorithm for high-data-rate nomadic users in such LTE-A systems. An upper bound of the mean Packet delay is derived and simulation results are also obtained. When compared with the mean Packet delay of a system in which component carriers are not aggregated but used independently, the presented scheme is shown to have significant improvement.
Troels Emil Kolding - One of the best experts on this subject based on the ideXlab platform.
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performance of spatial division multiplexing mimo with frequency domain Packet Scheduling from theory to practice
IEEE Journal on Selected Areas in Communications, 2008Co-Authors: Na Wei, Troels Emil Kolding, A Pokhariyal, Troels B Sorensen, Preben MogensenAbstract:This paper addresses the performance of spatial division multiplexing (SDM) multiple-input multiple-output (MIMO) techniques together with frequency domain Packet Scheduling (FDPS) in both theory and practice. We start with a theoretical analysis under some ideal assumptions to derive the performance bounds of SDM-FDPS. To facilitate the analysis, a unified SINR concept is utilized to make a fair comparison of MIMO schemes with different number of spatial streams. The effect of Packet Scheduling is included in the post-Scheduling SINR distribution using an analytical model. Based on that, the performance bounds are obtained with a more realistic SINR to throughput mapping metric. The system-level performance of SDM-FDPS has been evaluated under practical constraints using detailed simulations based on the UTRAN long term evolution (LTE) downlink cellular system framework. The purpose is to investigate the impact of realistic factors on performance. Results confirm that the combination of SDM and FDPS can increase the spectral efficiency significantly, particularly in a micro-cell scenario, and up to 30%-60% gain is observed over 1times2 with FDPS depending on the traffic models considered. Finally, the more practical simulation results are compared against the theoretical performance bounds. A performance loss is seen in the simulations due to realistic coding/modulation, impact of frequency selectivity, signalling constraints, imperfect channel quality indicator (CQI), etc.
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performance of mimo with frequency domain Packet Scheduling in utran lte downlink
Vehicular Technology Conference, 2007Co-Authors: Na Wei, Troels Emil Kolding, A Pokhariyal, Troels B Sorensen, Preben MogensenAbstract:This paper addresses the performance of spatial division multiplexing (SDM) multiple-input multiple-output (MIMO) techniques together with frequency domain Packet Scheduling (FDPS) based on UTRAN long term evolution (LTE) downlink. Two SDM concepts currently considered in 3GPP are the single-user (SU-) and the multi-user (MU-) MIMO. For MU-MIMO, multiple users can be scheduled on different streams on the same time-frequency resource, while SU-MIMO restricts one time-frequency resource to a single user. Both concepts are analyzed against the 1times2 maximal ratio combining (MRC) case, using the proportional fair (PF) criterion extended to frequency and spatial domains. The realistic finite buffer best effort traffic model is used in the study. Results show that in the macrocell scenario, the combination of FDPS and SDM (SDM-FDPS) without preceding achieves only marginal gain in cell throughput, due to limited SINR dynamic range. The gain is increased to around 20% when precoding is applied. In the micro-cell scenario, the gain of SDM-FDPS over the reference scheme is increased up to 35% with precoding.
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mitigating signaling requirements for mimo with frequency domain Packet Scheduling
Vehicular Technology Conference, 2007Co-Authors: Na Wei, Troels Emil Kolding, A Pokhariyal, Troels B Sorensen, Preben MogensenAbstract:MIMO techniques in the spatial division multiplexing (SDM) mode have demonstrated tremendous performance potential when a single user link is considered. Recent studies have shown that frequency domain Packet Scheduling (FDPS) can provide a significant gain when combined with SDM (SDM-FDPS) by exploiting the multi-user diversity gain over frequency as well as the spatial domains. However, the increased signaling requirements in both uplink and downlink may prevent its practical use. In this paper several effective approaches are identified for reducing the signaling requirements for SDM-FDPS while still maintaining acceptable performance. Results show that the performance loss can be kept within 10% for a uplink signaling reduction of 88% and a downlink signaling reduction of 30%.
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frequency domain Packet Scheduling under fractional load for the utran lte downlink
Vehicular Technology Conference, 2007Co-Authors: A Pokhariyal, Klaus I. Pedersen, Preben Mogensen, Claudio Rosa, Guillaume Monghal, Istvan Z Kovacs, Troels Emil KoldingAbstract:In this paper we investigate the performance of frequency domain Packet Scheduling (FDPS) under fractional load (FL), based on the UTRAN long term evolution downlink. Under FL, the Packet scheduler does not need to transmit on entire system bandwidth due to lack of traffic in the network, which leads to an improvement in the user experienced SINR. System-level simulations show that the proportional fair scheduler tries to optimize resource allocation by avoiding transmission on frequencies that are experiencing severe interference. As an example, FDPS can provide a gain of 4 dB in SINR over the round-robin scheduler, when the load is equal to 25%. The observed interference control is achieved without any centralized management. Further, FDPS under FL can provide an effective trade-off between cell throughput and coverage. The FDPS performance is dependent on the ability of link adaptation to track variations in interference. This ability is reduced when the frequency usage pattern is changing rapidly over time.
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performance of downlink frequency domain Packet Scheduling for the utran long term evolution
Personal Indoor and Mobile Radio Communications, 2006Co-Authors: A Pokhariyal, Troels Emil Kolding, Preben MogensenAbstract:In this paper we investigate the potential of downlink frequency domain Packet Scheduling (FDPS) for the 3GPP UTRAN long-term evolution. Utilizing frequency-domain channel quality reports, the scheduler flexibly multiplexes users on different portions of the system bandwidth. Compared to frequency-blind, but time-opportunistic Scheduling, FDPS shows gains in both average system capacity and cell-edge data rates on the order of 40%. However, the FDPS performance is shown to depend significantly on the frequency-domain Scheduling resolution as well as the accuracy of the channel state reports. Assuming Typical Urban channel profile, studies show that the Scheduling resolution should preferably be as low as 375 kHz to yield significant FDPS gain with two-branch receive diversity and in 20 MHz. Further, to have convincing FDPS gain the std. of error of radio state reports needs to be kept within 1.5-2 dB.
A Pokhariyal - One of the best experts on this subject based on the ideXlab platform.
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performance of spatial division multiplexing mimo with frequency domain Packet Scheduling from theory to practice
IEEE Journal on Selected Areas in Communications, 2008Co-Authors: Na Wei, Troels Emil Kolding, A Pokhariyal, Troels B Sorensen, Preben MogensenAbstract:This paper addresses the performance of spatial division multiplexing (SDM) multiple-input multiple-output (MIMO) techniques together with frequency domain Packet Scheduling (FDPS) in both theory and practice. We start with a theoretical analysis under some ideal assumptions to derive the performance bounds of SDM-FDPS. To facilitate the analysis, a unified SINR concept is utilized to make a fair comparison of MIMO schemes with different number of spatial streams. The effect of Packet Scheduling is included in the post-Scheduling SINR distribution using an analytical model. Based on that, the performance bounds are obtained with a more realistic SINR to throughput mapping metric. The system-level performance of SDM-FDPS has been evaluated under practical constraints using detailed simulations based on the UTRAN long term evolution (LTE) downlink cellular system framework. The purpose is to investigate the impact of realistic factors on performance. Results confirm that the combination of SDM and FDPS can increase the spectral efficiency significantly, particularly in a micro-cell scenario, and up to 30%-60% gain is observed over 1times2 with FDPS depending on the traffic models considered. Finally, the more practical simulation results are compared against the theoretical performance bounds. A performance loss is seen in the simulations due to realistic coding/modulation, impact of frequency selectivity, signalling constraints, imperfect channel quality indicator (CQI), etc.
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performance of mimo with frequency domain Packet Scheduling in utran lte downlink
Vehicular Technology Conference, 2007Co-Authors: Na Wei, Troels Emil Kolding, A Pokhariyal, Troels B Sorensen, Preben MogensenAbstract:This paper addresses the performance of spatial division multiplexing (SDM) multiple-input multiple-output (MIMO) techniques together with frequency domain Packet Scheduling (FDPS) based on UTRAN long term evolution (LTE) downlink. Two SDM concepts currently considered in 3GPP are the single-user (SU-) and the multi-user (MU-) MIMO. For MU-MIMO, multiple users can be scheduled on different streams on the same time-frequency resource, while SU-MIMO restricts one time-frequency resource to a single user. Both concepts are analyzed against the 1times2 maximal ratio combining (MRC) case, using the proportional fair (PF) criterion extended to frequency and spatial domains. The realistic finite buffer best effort traffic model is used in the study. Results show that in the macrocell scenario, the combination of FDPS and SDM (SDM-FDPS) without preceding achieves only marginal gain in cell throughput, due to limited SINR dynamic range. The gain is increased to around 20% when precoding is applied. In the micro-cell scenario, the gain of SDM-FDPS over the reference scheme is increased up to 35% with precoding.
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mitigating signaling requirements for mimo with frequency domain Packet Scheduling
Vehicular Technology Conference, 2007Co-Authors: Na Wei, Troels Emil Kolding, A Pokhariyal, Troels B Sorensen, Preben MogensenAbstract:MIMO techniques in the spatial division multiplexing (SDM) mode have demonstrated tremendous performance potential when a single user link is considered. Recent studies have shown that frequency domain Packet Scheduling (FDPS) can provide a significant gain when combined with SDM (SDM-FDPS) by exploiting the multi-user diversity gain over frequency as well as the spatial domains. However, the increased signaling requirements in both uplink and downlink may prevent its practical use. In this paper several effective approaches are identified for reducing the signaling requirements for SDM-FDPS while still maintaining acceptable performance. Results show that the performance loss can be kept within 10% for a uplink signaling reduction of 88% and a downlink signaling reduction of 30%.
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frequency domain Packet Scheduling under fractional load for the utran lte downlink
Vehicular Technology Conference, 2007Co-Authors: A Pokhariyal, Klaus I. Pedersen, Preben Mogensen, Claudio Rosa, Guillaume Monghal, Istvan Z Kovacs, Troels Emil KoldingAbstract:In this paper we investigate the performance of frequency domain Packet Scheduling (FDPS) under fractional load (FL), based on the UTRAN long term evolution downlink. Under FL, the Packet scheduler does not need to transmit on entire system bandwidth due to lack of traffic in the network, which leads to an improvement in the user experienced SINR. System-level simulations show that the proportional fair scheduler tries to optimize resource allocation by avoiding transmission on frequencies that are experiencing severe interference. As an example, FDPS can provide a gain of 4 dB in SINR over the round-robin scheduler, when the load is equal to 25%. The observed interference control is achieved without any centralized management. Further, FDPS under FL can provide an effective trade-off between cell throughput and coverage. The FDPS performance is dependent on the ability of link adaptation to track variations in interference. This ability is reduced when the frequency usage pattern is changing rapidly over time.
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performance of downlink frequency domain Packet Scheduling for the utran long term evolution
Personal Indoor and Mobile Radio Communications, 2006Co-Authors: A Pokhariyal, Troels Emil Kolding, Preben MogensenAbstract:In this paper we investigate the potential of downlink frequency domain Packet Scheduling (FDPS) for the 3GPP UTRAN long-term evolution. Utilizing frequency-domain channel quality reports, the scheduler flexibly multiplexes users on different portions of the system bandwidth. Compared to frequency-blind, but time-opportunistic Scheduling, FDPS shows gains in both average system capacity and cell-edge data rates on the order of 40%. However, the FDPS performance is shown to depend significantly on the frequency-domain Scheduling resolution as well as the accuracy of the channel state reports. Assuming Typical Urban channel profile, studies show that the Scheduling resolution should preferably be as low as 375 kHz to yield significant FDPS gain with two-branch receive diversity and in 20 MHz. Further, to have convincing FDPS gain the std. of error of radio state reports needs to be kept within 1.5-2 dB.
Yaoliang Chung - One of the best experts on this subject based on the ideXlab platform.
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an efficient downlink Packet Scheduling algorithm in lte advanced systems with carrier aggregation
Consumer Communications and Networking Conference, 2011Co-Authors: Yaoliang Chung, Lihjong Jang, Zsehong TsaiAbstract:Carrier Aggregation (CA) is one of the promising features to support the much wider bandwidth for Packet transmissions in Long Term Evolution-Advanced (LTE-A) systems. To the best of our knowledge, works regarding the Packet Scheduling algorithm in LTE-A systems with the CA mechanism have not thoroughly been investigated yet till now. In this paper, we therefore aim to design an efficient Packet Scheduling algorithm based on the proportional fair criterion in such environment. We focus on downlink transmissions supporting both Real-Time (RT) and non-RT traffics simultaneously. Simulation results show that performance measures in terms of the system throughput, the mean delay, and the fairness are much better than those of a system in which component carriers are not aggregated but used independently.
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a quantized water filling Packet Scheduling scheme for downlink transmissions in lte advanced systems with carrier aggregation
International Conference on Software Telecommunications and Computer Networks, 2010Co-Authors: Yaoliang Chung, Zsehong TsaiAbstract:Carrier Aggregation (CA) is one of the promising features in Long Term Evolution-Advanced (LTE-A) systems. Till now, works regarding the Packet Scheduling scheme with CA in different frequency bands have not completely been studied and evaluated yet. Thus, the purpose of this work aims to explore such issue and presents an efficient quantized water-filling Packet Scheduling algorithm for high-data-rate nomadic users in such LTE-A systems. An upper bound of the mean Packet delay is derived and simulation results are also obtained. When compared with the mean Packet delay of a system in which component carriers are not aggregated but used independently, the presented scheme is shown to have significant improvement.
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a quantized water filling Packet Scheduling scheme for downlink transmissions in lte advanced systems with carrier aggregation
International Conference on Software Telecommunications and Computer Networks, 2010Co-Authors: Yaoliang Chung, Zsehong TsaiAbstract:Carrier Aggregation (CA) is one of the promising features in Long Term Evolution-Advanced (LTE-A) systems. Till now, works regarding the Packet Scheduling scheme with CA in different frequency bands have not completely been studied and evaluated yet. Thus, the purpose of this work aims to explore such issue and presents an efficient quantized water-filling Packet Scheduling algorithm for high-data-rate nomadic users in such LTE-A systems. An upper bound of the mean Packet delay is derived and simulation results are also obtained. When compared with the mean Packet delay of a system in which component carriers are not aggregated but used independently, the presented scheme is shown to have significant improvement.
