Channel allocation schemes

About: Channel allocation schemes is a research topic. Over the lifetime, 10656 publications have been published within this topic receiving 182117 citations.

Optimal subchannel assignment in a two-hop OFDM relay

Abstract: The paper studies subchannel assignment in a two-hop OFDM relay system in which the transmitting nodes (source and relay) have access to channel information and interference-related information. We show that with L-superadditive relay (performance) functions a simple ranking of subchannels leads to the optimal assignment with a very low computational complexity. Numerical results quantify the benefit of subchannel assignment in a frequency-selective channel.

Game Theory Based Bandwidth Allocation Scheme for Network Virtualization

Abstract: Running multiple virtual networks over a shared physical network is a promising way to support diverse applications, consequently network virtualization is viewed as the keystone of the next-generation architecture. However, decoupling the role of traditional ISPs into Infrastructure Providers (InPs) and Service Providers (SPs), also brings some new challenges to us. For example, how to fairly and efficiently share the sacred physical resources of InPs among multiple SPs is a key problem. The interaction between InPs and SPs, such as cooperation and competition, makes this topic even more complicated. In this paper, we develop a novel approach to encourage efficient behavior in solving the interaction between InPs and SPs by introducing economic incentives, in the form of Game Theory. Based on the non-cooperative game model, a bandwidth allocation scheme in the network virtualization environment is established, using the concept of the Nash Equilibrium. Then we propose an iterative algorithm to find the Nash Equilibrium and solve the bandwidth allocation problem. Finally, we demonstrate the convergence and the effectiveness of our scheme in the experiments.

BER-Optimized Power Allocation for Fading Relay Channels

Abstract: Optimum power allocation is a key technique to realize the full potentials of relay-assisted transmission promised by the recent information-theoretic results. In this paper, we present a comprehensive framework for power allocation problem in a single-relay scenario taking into account the effect of relay location. In particular, we aim to answer the two fundamental questions: (Q1) How should the overall transmit power be shared between broadcasting and relaying phases?; (Q2) In the relaying phase, how much power should be allocated to relay-to- destination and source-to-destination links? The power allocation problem is formulated to minimize a union bound on the bit error rate (BER) performance assuming amplify-and-forward relaying. We consider both orthogonal and non-orthogonal cooperation protocols. Optimized protocols demonstrate significant performance gains over their original versions which assume equal sharing of overall transmit power between the source and relay terminals as well as between broadcasting and relaying phases. It is observed that optimized virtual (distributed) antenna configurations are able to demonstrate a BER performance as close as 0.4 dB within their counterpart co-located antenna configurations.

Spectrum Sharing and Cyclical Multiple Access in UAV-Aided Cellular Offloading

Abstract: In conventional terrestrial cellular systems, mobile terminals (MTs) at the cell edge often pose the performance bottleneck due to their long distance from the ground base station (GBS), especially in hotspot areas. This paper proposes a new hybrid network architecture by leveraging the use of unmanned aerial vehicle (UAV) as an aerial mobile base station, which flies cyclically along the cell edge to serve the cell- edge MTs and help offloading the traffic from the GBS. To achieve user fairness, we aim to maximize the minimum throughput of all MTs in a single cell by jointly optimizing the UAV's trajectory, as well as the bandwidth allocation and user partitioning between the UAV and GBS. Numerical results show that the proposed hybrid network with optimized spectrum sharing and cyclical multiple access design significantly improves the spatial throughput over the conventional cellular network with the GBS only.

A Resource Allocator for the Uplink of Multi-Cell OFDMA Systems

Abstract: We propose a simple distributed radio resource allocation algorithm for an OFDMA cellular system, which aims at minimizing the overall transmitted power subject to a rate constraint for each user. In order to reduce the problem complexity we use a single modulation; simulations show that the resulting performance degradation is negligible when the number of users is high enough. Moreover, we propose a simple distributed heuristic that, by reducing the rate constraints, steers the multicell system towards an stable resource allocation. Results show that the proposed system exhibits a great robustness to the destructive effects of multiple access interference.