A base station device and a terminal device determine resource element mapping in which a PDSCH is mapped and perform efficient communication. The terminal device uses a first parameter set among up to 4 parameter sets in order to determine resource element (RE) mapping for the PDSCH, when decoding the PDSCH based on detection of a Physical Downlink Control Channel (PDCCH) or an Enhanced Physical Downlink Control Channel (EPDCCH) with a Downlink Control Information (DCI) format 1A and transmitted on an antenna port 7, and determines RE mapping for the PDSCH by using the number of antenna ports for and/or a frequency position of a Cell-specific Reference Signal (CRS) in the serving cell when decoding the PDSCH based on detection of the PDCCH or the EPDCCH with the DCI format 1A and transmitted on antenna ports 0 to 3.

Terminal device, communication method, and integrated circuit

The mass and widespread adoption of connected mobile devices have brought about enormous social changes with significant economic, cultural, and technological impacts on a society that is becoming increasingly connected. Therefore, energy efficiency in future mobile generations is becoming increasingly significant for cellular network operators. To realize future green networks based on energy efficient architecture that meets the holistic requirements in terms of capacity, this paper presents an overview of the principal driving factors triggered by the next mobile generation, 5G, to fulfill the needed requirements. A detailed discussion of the various advantages and disadvantages of each of these techniques is performed to contribute to understanding how the green radio architecture for future mobile networks can be designed and what challenges may oppose this realization.

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How to Meet Increased Capacities by Future Green 5G Networks: A Survey

Due to the severely limited battery capacities, the energy efficiency of mobile devices plays an important role in their usability. In general, the cellular subsystem is one of the major contributors to the energy consumption of a mobile device, thus improving its energy efficiency is of paramount importance. In this paper, a new concept of pre-grant message together with associated control plane signaling is introduced, aiming to reduce the energy consumption of the cellular subsystem in the downlink, without notable increase in the buffering delay or latency. The proposed method is fully independent of the ordinary discontinuous reception (DRX) principle, which means that both methods can co-exist and act together to efficiently reduce the energy consumption of the user equipment. The performance of the proposed scheme in terms of the false alarm and misdetection rates are investigated and evaluated, in both additive white Gaussian noise and Rayleigh fading channels. The obtained numerical results show that the pre-grant message signaling can be decoded very reliably and can reduce the system power consumption, relative to an ordinary DRX-only reference system, by up to 70%, 68%, and 62% for FTP traffic, video streaming and VoIP, respectively, at the cost of negligible increase in the signaling overhead. The proposed method is also compared in terms of the energy consumption and energy efficiency against another state-of-the-art power-saving mechanism, namely the wake-up radio-based approach. The obtained results show that the pre-grant approach outperforms the wake-up-based system under broad range of traffic characteristics.

Pre-Grant Signaling for Energy-Efficient 5G and Beyond Mobile Devices: Method and Analysis

Mobile device batteries have severely limited capacities, due to constraints on size and weight of mobile devices. Therefore, energy efficiency of mobile devices plays an important role in their usability. Different power measurement studies show that cellular subsystem of mobile device is one of the major contributors to its energy consumption. Thus, reducing energy consumption of cellular subsystem is paramount. In this paper, a new concept of pre-grant message for control plane is introduced, aiming to reduce energy consumption of cellular subsystem in downlink, while discontinuous reception is activated. Performance of the proposed scheme in terms of false alarm and misdetection are investigated, and evaluated in AWGN and Rayleigh fading channel. The obtained numerical results show that such a signaling can reduce power consumption of mobile device by up to 70% for bursty data applications, at the cost of negligible increments in signaling overhead.

Robust Pre-Grant Signaling for Energy-Efficient 5G and beyond Mobile Devices

In recent years, people use multimedia applications which have become increasingly, such as watching IPTV or video streaming by smart phone. However, wireless user equipment (UE) is powered by battery which could only operate in a limited time. According those reasons, reducing the energy consumption of user equipment for communications is a major challenge. But in operator's opinion, they wish that users' throughput could as high as possible because they can have much more benefit. In this paper, we design a two-step algorithm which use scalable video coding technique to transmit multimedia data. First step, we allocate limited radio resource and not only maximize the total system throughput but also satisfy all of users as much as possible. Second step, we schedule the video layers which are already getting the radio resource and minimize total user equipment energy consumption. The simulation result shows that our proposed method can reduce much more energy consumption and increase throughput comparing with the existing method.

Energy-Efficient Multimedia Multicast Scheduling and Resource Allocation Algorithms for OFDMA-Based Systems

The Long Term Evolution (LTE) standard specifies the Discontinuous Reception Mechanism (DRX) mechanism for saving power at the User Equipment (UE). Here, a UE switches off its RF circuitry when there are no packets to be transmitted or received. The existing DRX algorithms use static operational parameters that are determined by the evolved nodeB (eNB) at the start of a UE's session. During the switch-off period, packets destined to the UE are buffered in the eNB leading to higher packet latency. This paper presents two adaptive algorithms to dynamically adjust the DRX parameters, in order to reduce both energy consumption and the extra delay incurred. The algorithms use application Quality-of-Service (QoS) and Channel Quality Information (CQI) to adjust the DRX parameters. Performance studies based on ns3 simulator show that the algorithms are able to reduce packet delay compared to static DRX by up to 60%, 60% and 75% and reduce energy consumption by up to 75%, 43% and 90% for video streaming, VoIP and bursty data applications respectively.

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Dynamic DRX algorithms for reduced energy consumption and delay in LTE networks

This paper presents an analytical model, based on a semi-Markov process, for determining the power savings achieved in a User Equipment (UE) device of a Long Term Evolution (LTE) network using the Discontinuous Reception (DRX) mechanism. Systems with and without packet buffers and the UE and enodeB are presented in this paper. Using the models, it is possible to determine the savings in power attainable by the UE when different DRX sleep cycles and timers are used. The analytical models has been validated using a discrete-event simulation model. The numerical results show that it is possible to obtain UE power savings of up to 63%.

Syama Varma R

Papers

Dynamic DRX algorithms for reduced energy consumption and delay in LTE networks

Analytical model for power savings in LTE networks using DRX mechanism