A Novel Beamformed Control Channel Design for LTE with Full Dimension-MIMO

The Full Dimension-MIMO (FD-MIMO) technology is capable of achieving huge improvements in network throughput with simultaneous connectivity of a large number of mobile wireless devices, unmanned aerial vehicles, and the Internet of Things (IoT). In FD-MIMO, with a large number of antennae at the base station and the ability to perform beamforming, the capacity of the physical downlink shared channel (PDSCH) has increased a lot. However, the current specifications of the 3rd Generation Partnership Project (3GPP) does not allow the base station to perform beamforming techniques for the physical downlink control channel (PDCCH), and hence, PDCCH has neither the capacity nor the coverage of PDSCH. Therefore, PDCCH capacity will still limit the performance of a network as it dictates the number of users that can be scheduled at a given time instant. In Release 11, 3GPP introduced enhanced PDCCH (EPDCCH) to increase the PDCCH capacity at the cost of sacrificing the PDSCH resources. The problem of enhancing the PDCCH capacity within the available control channel resources has not been addressed yet in the literature. Hence, in this paper, we propose a novel beamformed PDCCH (BF-PDCCH) design which is aligned to the 3GPP specifications and requires simple software changes at the base station. We rely on the sounding reference signals transmitted in the uplink to decide the best beam for a user and ingeniously schedule the users in PDCCH. We perform system level simulations to evaluate the performance of the proposed design and show that the proposed BF-PDCCH achieves larger network throughput when compared with the current state of art algorithms, PDCCH and EPDCCH schemes

A Novel Beamformed Control Channel Design for LTE with Full Dimension-MIMO

The Full Dimension-MIMO (FD-MIMO) technology is capable of achieving huge improvements in network throughput with simultaneous connectivity of a large number of mobile wireless devices, unmanned aerial vehicles, and the Internet of Things (IoT). In FD-MIMO, with a large number of antennae at the base station and the ability to perform beamforming, the capacity of the physical downlink shared channel (PDSCH) has increased a lot. However, the current specifications of the 3 rd Generation Partnership Project (3GPP) does not allow the base station to perform beamforming techniques for the physical downlink control channel (PDCCH), and hence, PDCCH has neither the capacity nor the coverage of PDSCH. Therefore, PDCCH capacity will still limit the performance of a network as it dictates the number of users that can be scheduled at a given time instant. In Release 11, 3GPP introduced enhanced PDCCH (EPDCCH) to increase the PDCCH capacity at the cost of sacrificing the PDSCH resources. The problem of enhancing the PDCCH capacity within the available control channel resources has not been addressed yet in the literature. Hence, in this paper, we propose a novel beamformed PDCCH (BF-PDCCH) design which is aligned to the 3GPP specifications and requires simple software changes at the base station. We rely on the sounding reference signals transmitted in the uplink to decide the best beam for a user and ingeniously schedule the users in PDCCH. We perform system level simulations to evaluate the performance of the proposed design and show that the proposed BF-PDCCH achieves larger network throughput when compared with th

Cellular Planning and Optimization for 4G and 5G Mobile Networks

Cellular planning and optimization of mobile heterogeneous networks has been a topic of study for several decades with a diversity of resources, such as analytical formulations and simulation software being employed to characterize different scenarios with the aim of improving system capacity. Furthermore, the world has now witnessed the birth of the first commercial 5G New Radio networks with a technology that was developed to ensure the delivery of much higher data rates with comparably lower levels of latency. In the challenging scenarios of 4G and beyond, Carrier Aggregation has been proposed as a resource to allow enhancements in coverage and capacity. Another key element to ensure the success of 4G and 5G networks is the deployment of Small Cells to offload Macrocells. In this context, this MSc dissertation explores Small Cells deployment via an analytical formulation, where metrics such as Carrier plus Noise Interference Ratio, and physical and supported throughput are computed to evaluate the system´s capacity under different configurations regarding interferers positioning in a scenario where Spectrum Sharing is explored as a solution to deal with the scarcity of spectrum. One also uses the results of this analyses to propose a cost/revenue optimization where deployment costs are estimated and evaluated as well as the revenue considering the supported throughput obtained for the three frequency bands studied, i.e., 2.6 GHz, 3.5 GHz and 5.62 GHz. Results show that, for a project life time of 5 years, and prices for the traffic of order of 5€ per 1 GB, the system is profitable for all three frequency bands, for distances up to 1335 m. Carrier Aggregation is also investigated, in a scenario where the LTE-Sim packet level simulator is used to evaluate the use of this approach while considering the use of two frequency bands i.e., 2.6 GHz and 800 MHz to perform the aggregation with the scheduling of packets being performed via an integrated common radio resource management used to compute Packet Loss Ratio, delay and goodput under different scenarios of number of users and cell radius. Results of this analysis have been compared to a scenario without Carrier Aggregation and it has been demonstrated that CA is able to enhance capacity by reducing the levels of Packet Loss Ratio and delay, which in turn increases the achievable goodput.O planeamento e otimização de redes de redes celulares heterogéneas tem sido um tópico de investigação por várias décadas com diversas abordagens que incluem formulações analíticas e softwares de simulação, sendo aplicados na caracterização de diferentes cenários, com o objetivo de melhorar a capacidade de sistema. Além disso, o mundo testemunhou o nascimento das primeiras redes 5G New Radio, com uma tecnologia que foi desenvolvida com o objetivo de garantir taxas de transferência de dados muito superiores, com níveis de latência comparativamente inferiores. Neste cenário de desafios pós-4G, a agregação de Espectro tem sido proposta como uma solução para permitir melhorias na cobertura e capacidade do sistema. Outro ponto para garantir o sucesso das redes 5G é a utilização de Pequenas Células para descongestionar as Macro células. Neste contexto, esta dissertação de mestrado explora a utilização de Pequenas Células através de uma formulação analítica, onde se avaliam métricas como a relação portadora-interferência-mais-ruído, débito binário e débito binário suportado, sob diferentes configurações de posicionamento de interferentes em cenários onde a partilha de espectro é explorada como uma solução para enfrentar a escassez de espectro. Os resultados dessa análise são também considerados para propor uma otimização de custos/proveitos, onde os custos de implantação são estimados e avaliados, assim como os proveitos ao se considerar o débito binário suportado obtido para as três bandas de frequência em estudo, a saber, 2.6 GHz, 3.5 GHz e 5.62 GHz. Os resultados demonstram que, para um tempo de vida do projeto de 5 anos, e para preços de tráfego de cerca de 5 € por GB, o sistema é lucrativo para as três bandas de frequência, para distâncias até 1335 m. Também se investiga a agregação de espectro recorrendo ao simulador de pacotes LTE-Sim para avaliar o uso de duas bandas de frequência, a saber, 2.6 GHz e 800 MHz, considerando agregação com a calendarização de pacotes por meio de um gestor comum de recursos de rádio integrado, utilizado para computar a taxa de perda de pacotes, o atraso e o débito binário na camada de aplicação, em cenários com diferentes valores de número de utilizadores e raios das células. Os resultados dessa análise foram comparados com o desempenho de um cenário sem agregação. Foi demonstrado que a agregação é capaz de aumentar a capacidade de sistema, ao reduzir os níveis de perda de pacotes e do atraso, o que por sua vez possibilita a elevação dos níveis de débito binário atingidos