6 results
Now showing1 - 6 of 6
- Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Markov Chain Monte Carlo Methods for a Low Complexity LTE-Advanced Joint DetectorTo meet the goal of tenfold increase in spectral efficiency, interference cancellation and multiuser detection are expected to be important tasks of fifth-generation (5G) radio access systems. Both tasks can be realized by joint detection algorithms. However, joint detection algorithms such as maximum likelihood (ML) detection have a high computational complexity. Previous works have shown that joint detectors based on Markov chain Monte Carlo (MCMC) methods can achieve similar results compared to ML detection with a large reduction in the computational complexity for systems with a large number of streams or users. The purpose of this work is to present a MIMO joint detector based on MCMC methods and evaluate it within the constraints of LTE Advanced (LTE-A), namely, using at most 8 transmit antennas and 64-QAM modulation. The evaluation is done separately from the channel decoder. Moreover, the complexity of the presented algorithm is compared to the one of an ML detector. The results show that the proposed MIMO detector offers a similar detection error rate compared to an ML detector. Furthermore, it was observed that the complexity reduction is significant for systems with more than six transmit antennas.Publicationtype: Conference Paper220 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Communication Analysis between an Airborne Mobile User and a Terrestrial Mobile NetworkMobile services like GSM and LTE are increasingly offered on board of long-haul flights. This is achieved by installing an onboard base station, namely a GSM BTS or an LTE eNodeB in the airplane. Additionally, the airplane is equipped with a network control unit (NCU) device which prevents onboard mobile users from attempting to connect to ground mobile networks and, therefore, affect or interfere with terrestrial communications. The objective of this paper is to evaluate the need of the network control unit. For that purpose, it is investigated if a mobile user in the airplane can establish a connection with an existing terrestrial GSM or LTE network without the presence of the network control unit and the onboard base station. Only a few studies exist which investigate this connection. The analysis done in this paper takes into consideration physical and high layer requirements of both GSM and LTE networks.Publicationtype: Journal Article185 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , 41 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Link analysis between an airborne mobile station and a terrestrial GSM networkThe use of mobile phones during long-haul flights is becoming more popular as airlines equip their aircrafts with onboard GSM and LTE base stations. Right now, this increasing number of aircraft users is restricted to the base station installed in the airplane. However, there are plans to use terrestrial mobile networks as an alternative to onboard base stations to serve aircraft users for certain parts of the flight route. Investigations about the interaction between flying mobile users and a terrestrial mobile network are scarce. In this work, the connection between a user on an airplane and an existing terrestrial GSM network non-optimized for airborne communication is analyzed. Several scenarios are investigated to determine if an onboard GSM user flying at an altitude between 3000 and 10000 meters can establish a connection with a ground GSM base station considering physical and higher layer requirements.Publicationtype: Conference Paper46 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Partial interference cancellation in heterogeneous LTE-advanced networksIn LTE networks, picocells are deployed to take over load from macrocells in areas of high user density or weak coverage. Their support comes at the cost of severe intercell interference if single frequency reuse is implemented. In this paper, a cooperative interference mitigation scheme is presented that combines the theoretical work on rate splitting of Han and Kobayashi with the transmission of MIMO-layers as it is defined in LTE. Two users from different cells form a cooperating pair. A cell-edge user detects a part of the interference such that the effective interference is decreased. Thus, it can be served at a higher data rate. This work focuses on an asymmetric scenario in which a cell-edge user and a cell-center user of neighboring cells form a cooperating pair. Simulations show that the cell-edge user can significantly improve its spectral efficiency compared to treating the whole interference as noise with only small losses for the cell-center user. The proposed scheme uses the tools available in LTE and adds only little overhead for the cooperation.Publicationtype: Conference Paper78 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Interference coordination-based downlink scheduling for heterogeneous LTE-A networks(2016-09-12); ; ; We propose a novel scheduler for an LTE-A network, which dynamically coordinates inter-cell interference for vulnerable users while limiting the effort of coordination. Vulnerable users are identified first, and then protected by assigning resources exclusively to them. Inter-cell interference coordination (ICIC) messages are transmitted to neighboring base stations (eNodeBs) via the X2 interface using LTE-Typical constraints. The proposed scheduler and ICIC methods are compliant with the LTE and LTE-A standards. Closed-loop spatial multiplexing is used. The proposed scheduler is evaluated in a 2-Tier heterogeneous network (HetNet). In comparison with the benchmark schedulers, simulation results for vulnerable users show a substantial gain in terms of throughput. In addition, the proposed scheduler guarantees a minimum data rate for a longer time.Publicationtype: Conference Paper125