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.

Dogfight in Spectrum: Combating Primary User Emulation Attacks in Cognitive Radio Systems—Part II: Unknown Channel Statistics

Abstract: In cognitive radio systems, primary user emulation (PUE) attack means that an attacker sends primary-user-like signals during the spectrum sensing period such that honest secondary users leave the corresponding channels, which causes a serious threat to cognitive radio systems. A passive anti-PUE approach, similar to the random frequency hopping in traditional anti-jamming schemes, is proposed and called dogfight in spectrum. In this scheme, the defenders randomly choose channels to sense and avoid the PUE attack. It is assumed that the channel statistics like availability probabilities are known; then the PUE attack and the random hopping are modeled as a zero-sum game between the attacker and defending secondary user(s). The Nash equilibrium of the game is found. The anti-jamming efficiency is also obtained. Numerical simulations demonstrated the performances of the proposed schemes for both the single defender, multiple defender and multiple round cases.

Optimal Resource Allocation for Two-Way Relay-Assisted OFDMA

Abstract: This paper studies the resource allocation problem for the relay-assisted orthogonal frequency-division multiple-access (OFDMA)-based multiuser system. A new transmission protocol, named hierarchical OFDMA, is proposed to support two-way communications between the base station (BS) and each mobile user (MU) with or without an assisting relay station (RS) in ldquorelayrdquo or ldquodirectrdquo mode, respectively. In particular, the recently discovered two-way relaying technology, based on the principle of network coding, is applied to MUs in relay mode with two possible relay-operations, namely, decode-and-forward (DF) and amplify-and-forward (AF). By applying convex optimization techniques, efficient algorithms are developed for optimal allocation of transmit resources such as power levels, bit rates, and OFDM subcarriers at the BS, RSs, and MUs. Simulation results show that substantial system throughput gains are achievable by the proposed two-way relaying and optimal resource allocation schemes over the traditional one-way relaying and fixed resource allocation schemes for relay-assisted OFDMA-based wireless networks.

Modeling wireless links for transport protocols

Abstract: Wireless links have intrinsic characteristics that affect the performance of transport protocols; these include variable bandwidth, corruption, channel allocation delays, and asymmetry. In this paper we review simulation models for cellular, WLAN and satellite links used in the design of transport protocols, and consider the interplay between wireless links and transport. We argue that the design and evaluation of transport protocols can be improved by providing easily available models of wireless links that strike a balance between realism, generality, and detail.There is an ongoing tussle between wireless link design and transport protocol design, with papers about how wireless link designers should take into account the dynamics of TCP, and other papers about how TCP and other transport protocols can be designed or modified for better performance over current wireless link technologies. In this paper we consider how appropriate models for wireless links can help in this tussle, and in the general design and evaluation of transport protocols over wireless links.

The Water-Filling Game in Fading Multiple-Access Channels

Abstract: A game-theoretic framework is developed to design and analyze the resource allocation algorithms in fading multiple-access channels (MACs), where the users are assumed to be selfish, rational, and limited by average power constraints. The maximum sum-rate point on the boundary of the MAC capacity region is shown to be the unique Nash equilibrium of the corresponding water-filling game. This result sheds a new light on the opportunistic communication principle. The base station is then introduced as a player interested in maximizing a weighted sum of the individual rates. A Stackelberg formulation is proposed in which the base station is the designated game leader. In this setup, the base station announces first its strategy defined as the decoding order of the different users, in the successive cancellation receiver, as a function of the channel state. In the second stage, the users compete conditioned on this particular decoding strategy. This formulation is shown to be able to achieve all the corner points of the capacity region, in addition to the maximum sum-rate point. On the negative side, it is shown that there does not exist a base station strategy in this formulation that achieves the rest of the boundary points. To overcome this limitation, a repeated game approach, which achieves the capacity region of the fading MAC, is presented. Finally, the study is extended to vector channels highlighting interesting differences between this scenario and the scalar channel case.

Assembly, and associated method, for facilitating channel frequency selection in a communication system utilizing a dynamic frequency selection scheme

Abstract: An assembly, and an associated method, for an ad hoc network, such as an independent basic service set defined in an IEEE 802.11 protocol specification. A channel map is created and maintained at each mobile station of the ad hoc network. The channel map is populated with channel characteristic indicia of channel frequencies that might be available upon which to be used in the ad hoc network to effectuate communications between the mobile stations. Information related to the channel map created and maintained at each of the mobile stations is exchanged, and any of the mobile stations is selectable to form a DFS owner that defines the channel frequency to be used upon which to define a communication channel for communications in the network.