{"title":"Design of low-latency uplink MAC scheduling for Massive MIMO-OFDM systems","authors":"Min Huang, Fangfang Yuan, Hong Cheng, Xu Zhang","doi":"10.1109/ICCW.2017.7962729","DOIUrl":"https://doi.org/10.1109/ICCW.2017.7962729","url":null,"abstract":"Massive MIMO is a promising technology for 5G due to its huge extended multi-user spatial multiplexing and beamforming capability, but its high complexity makes the associated MAC scheduling suffer from long processing time in practice. To solve such problem, this paper designs a low-latency uplink MAC scheduling scheme for Massive MIMO-OFDM systems. Specifically, first, a framework enabling processing parallelization is put forward in which the scheduling for multiple resource blocks (RB) are executed concurrently with the common pre-processing and post-processing. Second, a power-based weight is introduced into the per-RB scheduling, by which the link adaptation could be completed simultaneously with per-RB processing, no longer requiring reduplicate post-scheduling processing. Third, a low-complexity calculation method is applied to the per-layer recursive user selection algorithm for each RB, in which the matrix inversion is substituted by the recursion with vector inner-productions based on Hermitian Matrix Blockwise Inversion Lemma. Finally, performance simulation results demonstrate that the designed MAC scheduling scheme outperforms random scheduling in terms of both cell sum throughput and cell edge throughput.","PeriodicalId":6656,"journal":{"name":"2017 IEEE International Conference on Communications Workshops (ICC Workshops)","volume":"55 1","pages":"632-638"},"PeriodicalIF":0.0,"publicationDate":"2017-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76651177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Guidotti, A. Vanelli-Coralli, Màrius Caus, J. Bas, G. Colavolpe, T. Foggi, S. Cioni, Andrea Modenini, D. Tarchi
{"title":"Satellite-enabled LTE systems in LEO constellations","authors":"A. Guidotti, A. Vanelli-Coralli, Màrius Caus, J. Bas, G. Colavolpe, T. Foggi, S. Cioni, Andrea Modenini, D. Tarchi","doi":"10.1109/ICCW.2017.7962769","DOIUrl":"https://doi.org/10.1109/ICCW.2017.7962769","url":null,"abstract":"LTE-based satellite systems in LEO constellations are a promising solution for extending broadband coverage to areas not connected to a terrestrial infrastructure. However, the large delays and Doppler shifts over the satellite channel pose severe technical challenges to a traditional LTE system. In this paper, two architectures are proposed for a LEO mega-constellation realizing a satellite-enabled LTE system, in which the on-ground LTE entity is either an eNB (Sat-eNB) or a Relay Node (Sat-RN). Focusing on the latter, the impact of large delays and Doppler shifts on LTE PHY/MAC procedures is discussed and assessed. It will be shown that, while carrier spacings, Random Access, and RN attach procedures do not pose specific issues, HARQ requires substantial modifications. Moreover, advanced handover procedures will be also required due to the satellites' movement.","PeriodicalId":6656,"journal":{"name":"2017 IEEE International Conference on Communications Workshops (ICC Workshops)","volume":"1 1","pages":"876-881"},"PeriodicalIF":0.0,"publicationDate":"2017-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87769906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An enhanced Tomlinson-Harashima precoding scheme for high-order MU-MIMO transmissions in 5G networks","authors":"Xin Wang, Xiaolin Hou, Huiling Jiang, Lan Chen","doi":"10.1109/ICCW.2017.7962660","DOIUrl":"https://doi.org/10.1109/ICCW.2017.7962660","url":null,"abstract":"We propose a novel transmission scheme based on Tomlinson-Harashima precoding (THP) that serves as a practical downlink multi-user (MU) MIMO transmission scheme for future radio access networks. The transmission of reference signals (RSs) is an issue of THP because the modulo operation during the interference cancellation introduces ambiguities to the channel estimation if it is applied on RSs. Without the modulo operation, the power of RS symbols becomes uncontrollable which degrades the performance due to the transmission power constraints in practical systems. An existing solution is to use orthogonal resources to transmit RSs without interference cancellation, which increases the RS overhead especially for high-order MU-MIMO transmissions. We propose an enhanced precoding scheme that uses phase rotation to control the power of the RSs during the THP process and thus control the power of the RS symbols. Therefore, the loss in transmission power due to practical power constraints is less than that for legacy approaches, and the use of orthogonal resources is not needed to transmit the RS symbols. In practical application, a fast phase search method is introduced to find the feasible angles for the phase rotation with low complexity. Simulations show that the proposed scheme is superior to legacy processing schemes with respect to the bit error rate.","PeriodicalId":6656,"journal":{"name":"2017 IEEE International Conference on Communications Workshops (ICC Workshops)","volume":"4 1","pages":"217-221"},"PeriodicalIF":0.0,"publicationDate":"2017-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79853460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Multi-cell VLC: Multi-user downlink capacity with coordinated precoding","authors":"Thanh V. Pham, H. L. Minh, A. Pham","doi":"10.1109/ICCW.2017.7962702","DOIUrl":"https://doi.org/10.1109/ICCW.2017.7962702","url":null,"abstract":"This paper studies the multi-user performance of multi-cell visible light communication (VLC) systems with coordinated precoding among cells. Practically, separated LED arrays are employed to properly illuminate a large room/office. This configuration enables a multi-cell VLC system, which is analogous to that in mobile cellular networks. In such multi-cell systems supporting multiple users, the received signal at a user can severely be degraded not only by the interference caused by the signals that are intended to other users within the cell (intra-cell interference) but also by interference from signals of the other cells (inter-cell interference). In order to remove these interferences, we propose a coordinated precoding technique which allows coordination between VLC cells. We then investigate the optimal precoding matrix design to maximize the achievable sum capacity of users. The maximization problem is formulated as a convex optimization problem which can be solved efficiently by using standard software packages. Numerical results show that the proposed coordinated precoding outperforms the non-coordinated one.","PeriodicalId":6656,"journal":{"name":"2017 IEEE International Conference on Communications Workshops (ICC Workshops)","volume":"7 1","pages":"469-474"},"PeriodicalIF":0.0,"publicationDate":"2017-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80036840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wei Fang, M. Mukherjee, Lei Shu, Zhangbing Zhou, G. Hancke
{"title":"Energy utilization concerned sleep scheduling in Wireless Powered Communication Networks","authors":"Wei Fang, M. Mukherjee, Lei Shu, Zhangbing Zhou, G. Hancke","doi":"10.1109/ICCW.2017.7962717","DOIUrl":"https://doi.org/10.1109/ICCW.2017.7962717","url":null,"abstract":"Wireless Powered Communication Networks (WPCN) is one of the promising approaches to extend the lifetime of the energy-constrained wireless networks such as Wireless Sensor Networks (WSNs). With the advancement in energy harvesting in terms of Wireless Energy Transmission (WET), WPCN overcomes the problem of replacing fixed energy sources such as batteries in difficult access areas of industrial networks. However, residual energy along with harvested energy is not always enough to support the data transmission in IWSNs. This article introduces a energy utilization concerned sleep scheduling in WPCNs with an aim to balance network demands and residual energy with harvested energy. In the proposed scheme, when the harvested energy combined with residual energy is less than the energy consumption due to data transmission, then the sensor node goes to sleep-state in order to prevent death acceleration. As the sleep node obtains enough energy, this node goes to active-state in next epoch if the network demand increases. Finally, a trade-off between the time to harvesting energy and data transmission is obtained through extensive simulation.","PeriodicalId":6656,"journal":{"name":"2017 IEEE International Conference on Communications Workshops (ICC Workshops)","volume":"22 1","pages":"558-563"},"PeriodicalIF":0.0,"publicationDate":"2017-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74432693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Iardella, G. Nardini, G. Stea, A. Virdis, A. Frangioni, L. Galli, D. Sabella, Francesco Mauro, G. Dell'Aera, M. Caretti
{"title":"Flexible dynamic coordinated scheduling in virtual-RAN deployments","authors":"N. Iardella, G. Nardini, G. Stea, A. Virdis, A. Frangioni, L. Galli, D. Sabella, Francesco Mauro, G. Dell'Aera, M. Caretti","doi":"10.1109/ICCW.2017.7962645","DOIUrl":"https://doi.org/10.1109/ICCW.2017.7962645","url":null,"abstract":"Using Coordinated Scheduling (CS), eNodeBs in a cellular network dynamically agree on which Resource Blocks (not) to use, so as to reduce the interference, especially for cell-edge users. This paper describes a software framework that allows dynamic CS to occur among a relatively large number of nodes, as part of a more general framework of network management devised within the Flex5Gware project. The benefits of dynamic CS, in terms of spectrum efficiency and resource saving, are illustrated by means of simulation and with live measurements on a prototype implementation using virtualized eNodeBs.","PeriodicalId":6656,"journal":{"name":"2017 IEEE International Conference on Communications Workshops (ICC Workshops)","volume":"28 1","pages":"126-131"},"PeriodicalIF":0.0,"publicationDate":"2017-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73827625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"3D channel propagation in an indoor scenario with Tx rooftop & wall at 3.5 & 6 GHz","authors":"Yawei Yu, Jian-hua Zhang, Xinzhuang Zhang, Yu Zhang","doi":"10.1109/ICCW.2017.7962694","DOIUrl":"https://doi.org/10.1109/ICCW.2017.7962694","url":null,"abstract":"In this paper, we focus on the statistical characteristics of 3D channel propagation in indoor scenario with dense users. Measurements were performed at 3.5 and 6 GHz with 100 MHz by using an uniform cross-polarized rectangular transmitter (Tx) with 32 antennas and a cylindric cross-polarized receiver with 56 antennas. Placing the Tx at two different positions, against the wall which radiates signals forward and hanged on the rooftop which radiates signals downward, we repeat measurements and present comparative results of all 4 cases (2 frequency carriers × 2 Tx positions). Channel impulse response is obtained and key channel propagation parameters (angle information, 3D polarization components, etc) are extracted via the spatial-alternating generalized expectation-maximization algorithm. Results including power delay profile, delay spread, power angle spectrum, angle spread, cross polarization power ratios, channel capacity and capacity contribution ratios of eigenvalues, will provide further insights into 3D channel propagation.","PeriodicalId":6656,"journal":{"name":"2017 IEEE International Conference on Communications Workshops (ICC Workshops)","volume":"358 1","pages":"424-428"},"PeriodicalIF":0.0,"publicationDate":"2017-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80180140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Energy efficiency and spectral-efficiency tradeoff in downlink NOMA systems","authors":"Qiang Liu, Fangqing Tan, Tiejun Lv, Hui Gao","doi":"10.1109/ICCW.2017.7962665","DOIUrl":"https://doi.org/10.1109/ICCW.2017.7962665","url":null,"abstract":"Non-orthogonal multiple access (NOMA) has been investigated recently as a candidate radio access technology for the fifth generation (5G) mobile communication due to its high spectral efficiency (SE). Green radio (GR) which focuses on energy efficiency (EE) is becoming an inevitable trend. In this paper, we study the tradeoff between EE and SE in downlink NOMA systems. The tradeoff problem is formulated as an optimization problem in which the basic idea is to maximize EE under a satisfying minimum SE requirement. It is proved that the system EE is a strictly quasi-concave function of transmission power. By formulating the optimization problem as a bilayer optimization problem, the optimal solution to the optimization problem is obtained, including optimal power allocation coefficients among multiplexed users and optimal transmission power value. Simulation results are provided to further confirm our theoretical findings and the effectiveness of our proposed power allocation scheme for achieving a flexible tradeoff between EE and SE.","PeriodicalId":6656,"journal":{"name":"2017 IEEE International Conference on Communications Workshops (ICC Workshops)","volume":"59 1","pages":"247-252"},"PeriodicalIF":0.0,"publicationDate":"2017-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88011217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"WOLA processing: A useful tool for windowed waveforms in 5G with relaxed synchronicity","authors":"Y. Medjahdi, R. Zayani, H. Shaiek, D. Roviras","doi":"10.1109/ICCW.2017.7962689","DOIUrl":"https://doi.org/10.1109/ICCW.2017.7962689","url":null,"abstract":"One of the main 5G issues is to enable flexible multiple access to fragmented spectrum with relaxed synchronicity. Unfortunately, the classical OFDM cannot fulfill this criterion, since a tight synchronization is essential to ensure free-distortion multiple access. Windowing is one of the most popular approaches that have been proposed to overcome this problem. In this paper, we investigate the enhancement that can provide Weighted Overlap and Add (WOLA) processing to basic windowed waveforms. To this end, two schemes are considered W-OFDM and WCP-COQAM. The obtained results show that the proposed WOLA-OFDM and WOLA-COQAM schemes outperform the basic windowed ones confirming thus the effectiveness of WOLA processing as a powerful tool for windowed waveforms in multiuser asynchronous access.","PeriodicalId":6656,"journal":{"name":"2017 IEEE International Conference on Communications Workshops (ICC Workshops)","volume":"9 1","pages":"393-398"},"PeriodicalIF":0.0,"publicationDate":"2017-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79477082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Ahmed, R. Ferrús, Riccardo Fedrizzi, O. Sallent, N. Kuhn, E. Dubois, P. Gelard
{"title":"Satellite Gateway Diversity in SDN/NFV-enabled satellite ground segment systems","authors":"T. Ahmed, R. Ferrús, Riccardo Fedrizzi, O. Sallent, N. Kuhn, E. Dubois, P. Gelard","doi":"10.1109/ICCW.2017.7962770","DOIUrl":"https://doi.org/10.1109/ICCW.2017.7962770","url":null,"abstract":"This paper explores how to use Software Defined Networking (SDN) and Network Functions Virtualization (NFV) as two emerging technologies to support Satellite Gateway Diversity (GWD) solution in the forward link to provide next generation satellite system with higher capacity enhancement, failover and resiliency management. In this context, the gateway handover along with efficient traffic steering techniques are used to cope with the cases where gateway feeder links experience outage due to meteorological conditions or gateway failure. The handover typically implies that additional traffic is addressed towards another satellite gateway to handle the capacity reduction. Toward this objective, we propose an architecture framework to support GWD using SDN/NFV-enabled satellite ground segment and we evaluate our solution on a proof of concept experimental testbed based on OpenSAND emulated satellite network. The results show that our proposal can provide reasonably flexibility to handle failover and resiliency.","PeriodicalId":6656,"journal":{"name":"2017 IEEE International Conference on Communications Workshops (ICC Workshops)","volume":"1 1","pages":"882-887"},"PeriodicalIF":0.0,"publicationDate":"2017-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82256145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}