The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Multiple Input Multiple Output (MIMO) transmission improves downlink spectral efficiency and is a key feature of Release 7 High Speed Downlink Packet Access (HSDPA). When the Node-B is configured in the MIMO mode with secondary common control pilot channel (S-CPICH), the power amplifiers (PAs) for the two transmit antennas are not balanced. A common pre-coder is required to balance the PAs for legacy...
The multiple input multiple output (MIMO) technology and the distributed antenna system (DAS) have emerged as the promising candidates for the future mobile communications. In this paper, we observe the downlink (DL) transmission in a single-cell multi-user MIMO (MU-MIMO) system based on the distributed antennas for 3GPP Long Term Evolution-Advanced (LTE-A). It is found that the existing methods presented...
3GPP has recently approved a new work item for LTE-A to support enhanced inter-cell interference coordination (eICIC) for co-channel deployments of heterogeneous networks. The main focus is on the coordination of control and data channel interference between macro and low power nodes, e.g., relay, pico, and femto. Since the femto cells are randomly deployed by consumers with closed access and X2 interface...
Femtocells are envisioned to be deployed in indoor environments in order to improve both radio coverage and system capacity. This paper focuses on the self-organization of enterprise femtocells, which is certainly more challenging than that of home femtocells. In the context of 3GPP LTE, we propose solutions to automatically tune parameters such as radio spectrum, pilot power, resource blocks, and...
In this paper, we develop a simulation tool to study the performance of hybrid femtocell access in a High-Speed Downlink Packet Access (HSDPA) network. A hybrid resource allocation scheduler is developed in order to balance the tradeoff between open and closed femto access strategies. Performance in terms of macrocell traffic offloading is investigated under the dynamic configuration of a network...
Although vehicular ad hoc networks are emerging as a novel paradigm for safety services, supporting real-time applications (e.g., video-streaming, Internet browsing, online gaming, etc.) while maintaining ubiquitous connectivity remains a challenge due to both high vehicle speed, and non-homogeneous nature of the network access infrastructure. To guarantee acceptable Quality-of-Service levels and...
Multi-path is a technique to increase the reliability of the internet connection in IP network. The implementation of this technique can be described as a host with two TCP paths work together, when one of them fails the other will back up the connection. Since TCP does not support multi-homing, the right term for this technique is multi-path. The fairness problem arises when multi-path host uses...
In this paper, the mainly used packet scheduling algorithms in wireless communication system will be introduced. The 3rd Generation partnership long term evolution (3GPP LTE) will provide QoS guaranteed multimedia services which demand much higher downlink packet rate and lower HOL packet delay. So, a suitable packet scheduling algorithm is becoming more and more important in 3GPP LTE system. The...
In this paper, we first investigate the performance of the 3G WCDMA wireless channel, and we find a special character, that sometimes a sudden link blockage/ congestion happens and causes heavy throughput drops during a certain time in the given 3G channel. After getting the basic characteristics and information about the performance, a novel transmission control scheme is proposed based on the Gilbert...
According to network selection requirements for heterogeneous wireless networks, combining with the advantages and disadvantages of fuzzy logic algorithm, and using information fusion technology,a triangle module operator and fuzzy logic based handoff algorithm for heterogeneous wireless networks is designed in this paper. The proposed algorithm fused the result of the traditional signal strength...
A goal for next generation mobile networks is to provide seamless personal mobile communication and improved quality of service (QoS). Fair, class based service and lossless handoff are a focus for improving QoS. The research presented in this paper proposes a scheduling mechanism for providing improved QoS in mobile broadband Internet Protocol (IP) high-speed downlink packet access (HSDPA) networks...
The LTE standard supports a maximum throughput of 300MBit/s using 4×4 MIMO and a channel bandwidth of 20 MHz. At the same time the latest HSDPA technology supports 82MBit/s using 2×2 MIMO and Dual Cell techniques. While LTE uses a conflict-free interleaver, which allows highly efficient implementation of parallel decoders for such throughputs, HSDPA uses the UMTS interleaver that causes memory access...
Research on the integration of high altitude platform station (HAPS) with conventional 3G and future 4G mobile broadband communication networks has been increasing in the past few years due to various advantages the integrated system can offer. In this paper, we investigate a novel HAPS based mobile base station system using low altitude airship for high speed mobile broadband wireless services. Through...
As a promising radio access technology for next generation mobile communication systems, LTE (Long-Term Evolution) is being standardized by the 3rd Generation Partnership Project (3GPP) international standardization organization. LTE Release 8 has many advantages to the other systems, e.g., the peak throughput is 300Mbps in Downlink (DL) and 75Mbps in Uplink (UL), 2-3 time higher spectrum efficiency...
In this paper, a two-tier UMTS network is considered where a large number of randomly deployed Wideband Code Division Multiple Access (WCDMA) femtocells are laid under macrocells where the spectrum is shared. The co-channel interference between the cells may be a potential limiting factor for the system. We study the uplink of this hybrid network, and identify the critical scenarios that give rise...
Relaying is one of the key techniques considered by the 3GPP LTE-Advanced as part of 4G cellular technologies, aiming to increase the coverage and capacity of the network especially for the edge nodes. In this work, we have considered the uplink scheduling of an LTE network with the help of positioned relay nodes. We have projected the entire problem as a constrained optimization problem. As a solution,...
Coordinated Multi-Point Transmission and Reception (CoMP) has been regarded as an important component for Long Term Evolution-Advanced (LTE-A) which is currently standardized in the Third Generation Partnership Project (3GPP). CoMP is mainly expected to increase cell-edge User Equipment (UE) throughput and/or system throughput. In order to reach the desired performance, uplink power control is a key...
Wireless networks have been evolved to heterogeneous overlay structure, in which various wireless technologies provide partial or full coverage of the service area. Another evolution direction is multi-service wireless networks. In multi-service networks, traffic of various QoS classes is serviced concurrently. In this paper, we propose a scalable and flexible network selection scheme for multi-service...
The IMT-Advanced standardization process is executed by International Telecommunications Union Radiocommunication Sector (ITU-R) to define requirements to the next 4-th generation mobile communication systems and certify technologies meeting these requirements. This work presents results of the IEEE 802.16m and 3GPP LTE Release 10 technologies evaluation obtained by the Russian Evaluation Group (REG)...
In order to support development of third generation partnership project long term evolution (3GPP LTE) packet scheduling algorithms, research has been conducted into several radio propagation effects. The radio channels of interest are the downlink (eNodeB to user equipment) of LTE mobile networks. Through network simulator modification and repeated testing the effects of error and delay in reporting...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.