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This paper addresses the optimization of resource allocation based on Decode and Forward (DF) or Amplify and Forward (AF) relaying techniques for packet access Orthogonal Frequency Division Multiple Access (OFDMA) networks. A power allocation quasi-optimal solution with a low complexity has been proposed for the two forwarding techniques. To illustrate theirs performances, a selection of numerical...
In view of the new feature after introducing the relay nodes (RNs) into the conventional cellular networks, a novel soft frequency reuse (SFR)-based inter-cell interference coordination (ICIC) scheme is proposed in the relay enhanced cellular networks. On the basis of original ICIC scheme for conventional cellular network, RNs in the proposed SFR scheme reuses part of neighboring cell-edge bands to...
Interference mitigation and adaptive multi-user resource allocation are among the most promising technological breakthroughs that should improve capacity of future broadband wireless communications. In a multi-cell scenario, where co-channel interference is the performance limiting factor, discrete-rate resource allocation algorithms, selecting those channels with best Signal-to-Interference and Noise-Ratio...
This paper considers the use of predefined frequency-domain power profiles in downlink LTE-A aiming at making interference predictable across the Physical Resource Blocks, to be combined with fair resource allocation. In particular, the power profile structure is defined depending on the position of the users and fairness-oriented scheduling strategies are considered. Evaluations of the throughput...
The Physical Downlink Control Channel (PDCCH) is used to signal dynamic resource assignment information in the Long Term Evolution (LTE) system. In the presence of numerous active users, the system performance is likely to be hindered by shortage of control channel resource. In this paper, several simple algorithms are brought forward for making efficient PDCCH resource allocation. We first propose...
Block diagonalization is a linear precoding technique which eliminates the multi-user interference at the transmitter side by creating parallel orthogonal single user links. In this technique, the transmit diversity order is fixed for each user and only power can be controlled to satisfy SINR requirements. This restricts the degrees of freedom available for resource allocation and limits the energy...
Interference problems in cochannel femtocell networks may cause significant performance degradation for certain femtocell/macrocell users. These problems and potential solutions are recently being investigated within the 3GPP. The goal of the present paper is to review the simulation framework for femtocell networks in 3GPP and briefly summarize some of the important inter-cell interference coordination...
Cognitive wireless mesh networks have great potential to green communication. One of the critical challenges for realizing such networks is how to adaptively match transmit powers and allocate frequency resources among secondary users of the licensed frequency bands whilst maintaining the quality-of-service (QoS) requirement of the primary users, even in mutually entangled interferences environment...
A novel cell architecture based on Distributed Antenna Arrays for next generation mobile WiMAX systems is proposed. By exploiting Spatial Multiplexing and beamforming techniques, our target is to maximize the throughput of a high speed user by keeping low the deployment costs. Radio over Fiber is one of the best solutions to feed from a central point distributed arrays and share wireless resources...
In orthogonal frequency division multiple access (OFDMA) systems, efficient resource allocation is very important to improve the performance of the OFDMA system. The general principle of resource allocation in an OFDMA system is to assign each subcarrier to the user with the best channel condition for that subcarrier. However, in delay tolerant traffic, current work did not consider that packets on...
Fractional frequency reuse for the downlink of multicellular WiMAX networks is examined in this work. Three different schemes are evaluated through simulations, including distance-based and SINR-based approaches, as well as a new scheme which is based on load-balancing between different reuse regions. The proposed load-balancing scheme overcomes the main weakness of the SINR-based approach, namely...
Single-Carrier Frequency Division Multiple Access (SC-FDMA) has been selected as the uplink transmission scheme in the 3GPP Long Term Evolution standard. SC-FDMA is a form of Single-Carrier Frequency Domain Equalization (SCFDE) with flexibility in its resource allocation. In this paper we investigate the performance of SC-FDMA with Frequency-Domain Linear Equalization (FD-LE) with optimized transmit...
This paper presents a time-efficient optimal resource allocation algorithm aiming to maximize the system throughput of the single-user High Speed Downlink Packet Access (HSDPA) deployed in a femtocell base station. The system throughput maximization with constrained total power is formulated as a constrained integer programming problem. We first prove that a two-group bit and energy allocation provides...
This paper proposes suboptimal precoding vector (PV) selection schemes combined with frequency domain scheduling when closed-loop MIMO precoding is adopted in the LTE (Long-Term Evolution)-Advanced uplink based on single carrier-frequency division multiple access (SC-FDMA) radio access. In the proposed schemes, frequency domain channel-dependent scheduling is performed based on a tentatively selected...
In this paper we consider the Downlink Beamforming (DLBF) and resource allocation problem in MIMO-OFDMA systems. We consider the sum-power minimization or margin adaptive problem. This is a variable Signal to Interference and Noise Ratio (SINR), non-convex optimization problem and many aspects of this problem are not well understood. By using uplink downlink duality we first obtain the expression...
This paper investigates the properties of social choice functions, that represent resource allocation strategies in interference coupled wireless systems. The resources can be physical layer parameters such as power vectors or antenna weights. The paper investigates the permissible social choice functions, which can be implemented by a mechanism in either Nash equilibria or dominant strategy - for...
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