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We propose an adaptive scheme of a differential codebook for temporally correlated channels. The codeword entries of the proposed codebook are selected among the set of M-PSK constellations and the values of M proposed in this paper are 8, 16, or 32. Firstly, we analyze mathematically how the optimal spherical cap radius of the proposed codebook is tracked. Then, we explain how to implement the proposed...
An autonomous downlink interference control method for closed subscriber group (CSG) Long Term Evolution (LTE) femtocells is proposed. The proposed method integrates three interference control methods — power control, timing synchronization, and resource partitioning — by leveraging measurement results in various environments. The interferences on physical downlink data channel (PDSCH) and physical...
In 3GPP LTE Release-11 the Enhanced Physical Downlink Control Channel (EPDCCH) has been specified for downlink and uplink radio resource assignment notifications to User Equipments (UEs). EPDCCH has been designed to overcome several limitations of the Physical Downlink Control Channel (PDCCH) used in LTE Release 8–10. Some of the important design objectives of EPDCCH are: increased capacity for DL...
Multiuser multiple-input multiple-output (MU-MIMO) wireless systems that employ single-carrier frequency-domain equalization (SC-FDE) for uplink transmissions can provide high data rates with increased spectral efficiency under severe channel conditions. However, the availability of accurate channel estimates at the base station (BS) receiver is crucial for achieving peak performance. In this paper,...
In this paper, we propose a strategy for resource allocation for different traffic classes at the Medium Access Control (MAC) layer of wireless systems based on Orthogonal Frequency Division Multiple Access (OFDMA), such as the recent Long-Term Evolution (LTE) wireless standard. In order to achieve inter-class fairness, we propose a modification of the Virtual Token Modified Largest Weighted Delay...
The interaction between Machine-to-Machine (M2M) Communications, also known as Machine-Type Communications (MTC), and Human-to-Human (H2H) Communications is a recent topic in the context of cellular networks like Long Term Evolution (LTE). In this paper, we evaluate the performance of Channel-Aware MTC (CAT) based on LTE resource allocation measurements of a real LTE deployment. By means of a novel...
The long term evolution (LTE) networks provide high data rate access to support multi-media services at the expense of more power consumption in user equipment (UE). Discontinuous reception (DRX) mechanism is one of the promising technologies for energy saving in LTE networks, which extends UE battery lifetime effectively. The DRX parameters configuration should make a compromise between power saving...
Self-adaptation is a key factor for the future evolution of mobile networks due to their increasing complexity and required management efforts. In this paper, we propose an autonomous self-adaptive scheme based on Harmony Search (HS) Algorithm for radio resource management and interference coordination. One of the main strong points of the proposed scheme is that the computations are independent on...
Scheduling with single carrier property restriction has a significant impact on system performance in Long Term Evolution (LTE) uplink (UL). Due to the unavoidable delay of control signaling, the scheduling decisions have great influence on the variation of inter-cell interference (ICI) which affects the performance of adaptive modulation and coding (AMC). Many studies have been carried out on the...
Long Term Evolution (LTE) is considered the most promising cellular system able to support the growing demand of multicast services (e.g., IPTV, video streaming) over mobile terminals. The design of effective strategies for the management of these applications is still an open issue, especially in scenarios where several multicast streams are simultaneously transmitted in a cell. In this paper we...
Due to the power consumption issue of user equipment (UE), Single-Carrier FDMA (SC-FDMA) has been selected as the uplink multiple access scheme of 3GPP Long Term Evolution (LTE). Similar to OFDMA downlink, SC-FDMA enables multiple UEs to be served simultaneously in uplink as well. However, the single carrier characteristic requires that all the allocated subcarriers to a UE must be contiguous in frequency...
A heterogeneous network (HetNet) contains macrocells and different small cells, such as picocells, femtocells, and relay nodes. In HetNets, small cells are used to increase network capacity. Femtocells are usually used to increase coverage range in indoor environment, and can be deployed by users arbitrary. Besides, carrier aggregation is a major improvement in Long-Term-Evolution-Advanced (LTE-Advanced),...
In this paper we consider the use of an energy efficient, mobility state based flexible scanning mechanism for the discovery of small cells deployed in a different carrier. The evaluated scheme considers the mobility state of the mobile terminal in a heterogeneous network scenario for determining the inter-frequency scanning rate and suspends inter-frequency measurements when the terminal is in high...
Mobility Load Balancing (MLB) is a Self-Organising Networks (SON) use case with the scope of detecting and resolving radio overload. In case of overload, the MLB triggers the handover of cell edge users towards less loaded neighbour cells to better align the traffic demand with the capacity available on the air interface. This, however, also increases the load on the transport links of these cells;...
The growing popularity of the high-end mobile computing devices — smartphones, tablets, notebooks and more — equipped with high-speed network access, enables the mobile user to watch multimedia content from any source on any screen, at any time, while on the move or stationary. In this context, the network operators must ensure smooth video streaming with the lowest service delay, jitter, and packet...
In the context of internet of things, mobile operators face the challenge to host millions of devices with various capabilities and intelligence. With the traditional connectivity management in Long Term Evolution / Evolved Packet System (LTE/EPS) networks, security services such as confidentiality and integrity protection are designed to be activated in a systematic manner leading to significant...
The universal frequency reuse has been targeted for the Long Term Evolution. It leads to a harmful inter-cell interference experienced notably by the cell-edge users. The uplink inter-cell interference coordination becomes among the most important challenges. Throughout literature, many techniques were proposed to overcome this issue. Among these techniques, the soft frequency reuse concept grasped...
Indoor coverage is essential to the mobile user experience, because the signal power from the remote macro base stations is seriously weakened after penetrating the walls. Traditional indoor coverage system is a good solution but it can not be deployed in all the buildings. In order to enhance the received signal power inside the building, a relay can be used in a long term evolution (LTE) system...
As one of the key technical challenges in long term evolution (LTE)-Advanced heterogeneous networks (HetNets) is intercell interference coordination, many different schemes, such as coordinated multipoint (CoMP) and almost blank subframe (ABS) schemes, have been proposed in this field. Different cells are pushed to cooperate to eliminate intercell interference in CoMP coordinated beamforming, but...
The increasing adoption of Machine Type Communication (MTC) applications using the Long Term Evolution (LTE) brings new challenges for the traditional bearer allocation and network management. MTC devices are high in number, each requiring an individual bearer for a short data transmission; an inefficient process considering the signaling and management effort to the duration of the actual bearer...
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