Design of DMRS schemes for 5G vehicular communications

Proceeding of: 2021 IEEE 93rd Vehicular Technology Conference (VTC2021-Spring), 25-28 April 2021, Helsinki, Finland (Virtual edition)The arrival of the fifth generation (5G) of mobile communications is boosting vehicular communications, an important use case addressed in the recent years. LTE introduced a sidelink radio interface through which user equipment would communicate directly with no necessary dependence on the network, named PC5. 5G has defined its own sidelink interface, NR-Sidelink, envisaged to improve PC5. This paper analyses the use of Demodulation Reference Signals (DMRS) to estimate the channel in sidelink communications. Improving several mappings proposed by the standards, the main contribution proposed in this paper is a new DMRS mapping with a better performance. The proposed Unequal Pilot Spacing (UPS) mapping can enhance the standard with a satisfactory trade-off between performance and overhead.This work has been supported by the Spanish National Project TERESA-ADA (TEC2017-90093-C3-2-R) (MINECO/AEI/FEDER, UE)

Reducing the interference by adapting the power of OFDM for mMTC

Proceedings of: 2018 IEEE 87th Vehicular Technology Conference (VTC Spring)The Fifth Generation of mobile communications (5G) is being standardized based on Orthogonal Frequency Division Multiplexing (OFDM) waveforms. The high out-of-band emissions (OBE) are one of the main drawbacks of OFDM, which reduce the spectral efficiency and force us to leave wide guard bands. A strong candidate to replace OFDM is filtered-OFDM (f-OFDM) which solves the mentioned issue and keeps the backward compatibility. However, it increments the inter-symbol interference (ISI) due to the use of digital filters. We propose a new technique to overcome this problem. It is based on shaping the power of OFDM by the scheduler according to the demanded rates and channel quality of the users, while decreasing the OBE and avoiding the ISI increase. The interference generated by our proposed technique on a narrow-band signal based on legacy OFDM is analyzed. Moreover, simulations are performed to validate the theoretical analysis and some examples of implementation are also provided in the context of 5G evolution.This work has been partly funded by projects MACHINE (TSI-100102-2015-17), TERESA-ADA (TEC2017-90093-C3-2-R) (MINECO/AEI/FEDER, UE) and ELISA (TEC2014-59255-C3-3-R)

Perceived Video Quality Estimation from Spatial and Temporal Information Contents and Network Performance Parameters in IPTV

The paper proposes a model for estimation of perceived video quality in IPTV, taking as input both video coding and network Quality of Service parameters. It includes some fitting parameters that depend mainly on the information contents of the video sequences. A method to derive them from the Spatial and Temporal Information contents of the sequences is proposed. The model may be used for near real-time monitoring of IPTV video quality

Análisis de prestaciones de eMBMS en LTE: redes de frecuencia única

La ponencia presentada en: XXVIII Simposium Nacional de la Unión Científica Internacional de Radio. URSI 2013. Santiago de Compostela, 11-13 Sept. 2013.Mobile video is one of the most popular uses for mobile broadband networks. Based upon evolved Multimedia Broadcast Multicast Service (eMBMS) available with 3GPP release 9, LTE can provide broadcast/multicast content delivery with a single-frequency network mode that send the same multimedia content to mass audience within a specific area. In this paper, we carry out a Signal to Interference plus Noise Ratio (SINR) performance analysis for this type of networks, using OPNET Modeler tool. Several scenarios have been considered, with different number of users receiving multicast video data from the same source and different number of eNodeBs. This study includes the comparison of SINR in scenarios with 1, 3 and 7 different frequencies using multicast without MBMS or with MBMS SFN. The results show a comparison in the cell throughput between the different scenarios, as well as the performance obtained using different sizes of MBMS SFN areas.Este trabajo ha sido en parte financiado por el Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica, proyecto LTExtreme (IPT-2012- 0525-430000).Publicad

Joint multicast/unicast scheduling with dynamic optimization for LTE multicast service

This proceeding at: European Wireless 2014, took place 2014 Mai, 14-16, in Barcelona (España). The event web site of http://www.ew2014.org/Mobile video service is one of the most increasing uses expected in future generation cellular networks, including multicast video services. Based upon Evolved Multimedia Broadcast and Multicast Service (eMBMS) available with 3rd Generation Partnership Project (3GPP) release 9, Long Term Evolution (LTE) can provide broadcast/multicast content delivery with a single-frequency network mode. This means sending the same multimedia content to a mass audience within a specific area. However, it is not always possible to use multicast transmission to every user because of their different channel conditions, so unicast transmission should also be used to fulfill Quality of Service (QoS) requirements for multicast services. This paper proposes a Joint Multicast/Unicast Scheduling (JMUS) strategy for multicast service delivery. This method is based on dynamic optimization at each LTE frame, obtaining the optimal Modulation and Coding Scheme (MCS) for multicast transmission, the optimal number of subframes reserved for multicast transmission and allocating the remaining resources using a unicast scheduling metric for guaranteed data-rate. The goal of the scheduling technique proposed is to maximize the overall throughput, guaranteeing a target bit rate for all the users in the area. A new JMUS with dynamic optimization is presented to improve QoS performance. Finally, a fast search algorithm is evaluated to approach the optimal values for dynamic optimization with an order of magnitude fewer iterations than using exhaustive search.This work was supported in part by the Spanish Min-istry of Economy and Competitiveness, National Plan for Scienti?c Research, Development and Technological Inno-vation (INNPACTO subprogram), LTExtreme project (IPT- 2012-0525-430000) and the subproject TEC2011-29006-C03-03 (GRE3N-SYST).Publicad

Resource Allocation Management for Broadcast/Multicast Services

Ponencia presentada en: XXX Simposium Nacional de la Unión Científica Internacional de Radio, los dias 2 y 4 septiembre 2015, en Pamplona (españa).Video services are expected to become more than 70% of the mobile traffic in 2020. Broadcast and multicast service is the most efficient mechanism to deliver the same content to many users. Not only focusing on venue casting, but also distributing many other media such as software updates and breaking news, 5G broadcasting is a key driver to achieve the spectral efficiency needed for the 1,000 times traffic growth that is expected for the upcoming years. Improvements in some areas, such as resource allocation techniques for broadcast/multicast services, are needed. The utilization of the Conventional Multicast Scheme (CMS) approach for multicast resource allocation presents intrinsic inefficiencies, because of the different channel conditions of the users which demand the service. This paper presents some resource allocation strategies based on the use of multicast subgroups. We propose a multicast resource allocation algorithm including memory, which results in improvements of the service throughput at the time a high fairness among the users is guaranteed. In addition, an algorithm of joint resource allocation among multicast and unicast transmissions is developed. This strategy allows the system to take advantage of the subframes reserved for each purpose by the Long Term Evolution (LTE) standard, looking for the best joint allocation of the available resources, and results in important improvements in the service throughputThis work was supported in part by the Spanish Ministry of Economy and Competitiveness, National Plan for Scientific Research, Development and Technological Innovation (IN-NPACTO subprogram), LTExtreme project (IPT-2012-0525-430000), and the projects TEC2011-29006-C03-03 (GRE3NSYST) and TEC2014-59255-C3-3-R (ELISA).Publicad

Joint Strategy for LTE Resource Allocation: Multicast Subgrouping & Unicast Transmissions

La ponencia presentada en: XII Jornadas de Ingeniería Telemática (JITEL 2015), celebrada los días 14 al 16 de octubre de 2015, en Palma de Mallorca.Mobile broadband services are growing rapidly in the last few years due to the deployment of Long Term Evolution (LTE) cellular networks. Among them, multicast services can be provided using Evolved Multimedia Broadcast and Multicast Service (eMBMS), available with 3rd Generation Partnership Project (3GPP) release 9, which can deliver broadcast/multicast content using a single-frequency network mode. This means sending the same multimedia content to a mass audience within a specific area. The utilization of the Conventional Multicast Scheme (CMS) approach for multicast resource allocation presents intrinsic inefficiencies, because of the different channel conditions of the users which demand the service. This paper proposes a Joint Multicast Subgrouping and Unicast Transmissions (JMSUT) strategy for resource allocation, which consists of the use of the multicast and the unicast transmissions, by means of the subframes reserved by the LTE standard for each purpose, to deliver a multicast service. The goal of the JMSUT algorithm is to maximize the service throughput whereas it guarantees the fulfillment of the Quality of Service (QoS) requirements of every user. This paper solves the former maximization problem of the joint resource allocation; on the one hand, splitting the multicast resources into different subgroups that transmit the same content with different Modulation and Coding Scheme (MCS), and on the other hand, the users with worst channel conditions are served by means of the unicast transmissions.This work was supported in part by the Spanish Ministry of Economy and Competitiveness, National Plan for Scientific Research, Development and Technological Innovation (IN-NPACTO subprogram), LTExtreme project (IPT-2012-0525- 430000), and the project TEC2014-59255-C3-3-R (ELISA).Publicad

Estimation of Perceived Quality in Convergent Services

Triple-Play (3P) and Quadruple-Play (4P) services are being widely offered by telecommunication services providers. Such services must be able to offer equal or higher quality levels than those obtained with traditional systems, especially for the most demanding services such as broadcast IPTV. This paper presents a matrix-based model, defined in terms of service components, user perceptions, agent capabilities, performance indicators and evaluation functions, which allows to estimate the overall quality of a set of convergent services, as perceived by the users, from a set of performance and/or Quality of Service (QoS) parameters of the convergent IP transport networ

Estimating Perceived Video Quality from Objective Parameters in Video over IP Services

In Video over IP services, perceived video quality heavily depends on parameters such as video coding and network Quality of Service. This paper proposes a model for the estimation of perceived video quality in video streaming and broadcasting services that combines the aforementioned parameters with other that depend mainly on the information contents of the video sequences. These fitting parameters are derived from the Spatial and Temporal Information contents of the sequences. This model does not require reference to the original video sequence so it can be used for online, real-time monitoring of perceived video quality in Video over IP services. Furthermore, this paper proposes a measurement workbench designed to acquire both training data for model fitting and test data for model validation. Preliminary results show good correlation between measured and predicted values

TeamUp5G: a multidisciplinary approach to training and research on new RAN techniques for 5G ultra-dense mobile networks

Proceeding of: 12th IEEE/IET International Symposium on Communication Systems, Networks and Digital Signal Processing, (CSNDSP), 20-22, July 2020, (online).This paper presents a summary of the main research directions being followed in TeamUp5G European Training Network, teaming up a new generation of researchers and entrepreneurs ready to address complex engineering problems and innovation to work both at university and industry in the 5G field. This project is focused on new radio access network (RAN) techniques for 5G, considering ultradense mobile networks as a key ingredient of the actual mobile networks and their evolution. Research covers a wide spread of topics from physical layer and medium access control to applications, looking at spectrum sharing and energy efficiency as important features.This work has received funding from the European Union (EU) Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie ETN TeamUp5G, grant agreement No. 813391