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.

Modeling the coexistence of LTE and WiFi heterogeneous networks in dense deployment scenarios

Abstract: Rapid increases in mobile data demand and inherently limited RF spectrum motivate the use of dynamic spectrum sharing between different radio technologies such as WiFi and LTE, most notably in small cell (HetNet) scenarios. This paper provides a analytical framework for interference characterization of WiFi and LTE for dense deployment scenarios with spatially overlapping coverage. The first model developed is for single LTE and single WiFi access points separated by a specified distance. Results obtained for that model demonstrate the fact that WiFi is significantly degraded by a nearby LTE system, while LTE degradation is minimal as long as the WiFi system is within carrier sense range. A second model for multiple WiFi and multiple LTE systems further demonstrates the fact that LTE causes significant degradation to WiFi and that overall system throughput first increases and then decreases with growing density. Intra- and inter- system channel coordination schemes are considered as a means of improving system performance, and results are presented showing 4-5x gains in system capacity over comparable no coordination cases.

Hybrid Centralized-Distributed Resource Allocation for Device-to-Device Communication Underlaying Cellular Networks

Abstract: The basic idea of device-to-device (D2D) communication is that pairs of suitably selected wireless devices reuse the cellular spectrum to establish direct communication links, provided that the adverse effects of D2D communication on cellular users is minimized and cellular users are given a higher priority in using limited wireless resources. Despite its great potential in terms of coverage and capacity performance, implementing this new concept poses some challenges, in particular with respect to radio resource management. The main challenges arise from a strong need for distributed D2D solutions that operate in the absence of precise channel and network knowledge. In order to address this challenge, this paper studies a resource allocation problem in a single-cell wireless network with multiple D2D users sharing the available radio frequency channels with cellular users. We consider a realistic scenario where the base station (BS) is provided with strictly limited channel knowledge while D2D and cellular users have no information. We prove a lower-bound for the cellular aggregate utility in the downlink with fixed BS power, which allows for decoupling the channel allocation and D2D power control problems. An efficient graph-theoretical approach is proposed to perform the channel allocation, which offers flexibility with respect to allocation criterion (aggregate utility maximization, fairness, quality of service guarantee). We model the power control problem as a multi-agent learning game. We show that the game is an exact potential game with noisy rewards, defined on a discrete strategy set, and characterize the set of Nash equilibria. Q-learning better-reply dynamics is then used to achieve equilibrium.

Database-Assisted Distributed Spectrum Sharing

Abstract: According to FCC's ruling for white-space spectrum access, white-space devices are required to query a database to determine the spectrum availability. In this paper, we study the database-assisted distributed white-space access point (AP) network design. We first model the cooperative and non-cooperative channel selection problems among the APs as the system-wide throughput optimization and non-cooperative AP channel selection games, respectively, and design distributed AP channel selection algorithms that achieve system optimal point and Nash equilibrium, respectively. We then propose a state-based game formulation for the distributed AP association problem of the secondary users by taking the cost of mobility into account. We show that the state-based distributed AP association game has the finite improvement property, and design a distributed AP association algorithm that can converge to a state-based Nash equilibrium. Numerical results show that the algorithm is robust to the perturbation by secondary users' dynamical leaving and entering the system.

Side Channel: Bits over Interference

Abstract: Interference is a critical issue in wireless communications. In a typical multiple-user environment, different users may severely interfere with each other. Coordination among users therefore is an indispensable part for interference management in wireless networks. It is known that coordination among multiple nodes is a costly operation taking a significant amount of valuable communication resource. In this paper, we have an interesting observation that by generating intended patterns, some simultaneous transmissions, i.e., "interference,” can be successfully decoded without degrading the effective throughput in original transmission. As such, an extra and "free” coordination channel can be built. Based on this idea, we propose a DC-MAC to leverage this "free” channel for efficient medium access in a multiple-user wireless network. We theoretically analyze the capacity of this channel under different environments with various modulation schemes. USRP2-based implementation experiments show that compared with the widely adopted CSMA, DC-MAC can improve the channel utilization efficiency by up to 250 percent.

Channel allocation method, communication system, and wireless communication apparatus in wireless network

Abstract: In a wireless communication system with a periodical frame structure, as a method for transmitting information using an allocated channel over a plurality of frames by a single channel allocation request, an allocated channel is released when transmission is terminated or when a communication apparatus is disconnected from a network, and a channel can be allocated over a plurality of continuous frames.