scispace - formally typeset
Search or ask a question
Topic

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.


Papers
More filters
Proceedings ArticleDOI
01 Sep 2006
TL;DR: This work proposes a suboptimal scheme that can be obtained at lower complexity while still achieving good spectrum utilization, and is constructed based on the idea of a dynamic interference graph that captures the interfering effects.
Abstract: We consider a cognitive radio network in which a set of base stations make opportunistic unlicensed spectrum access to transmit data to their subscribers. As the spectrum of interest is licensed to another (primary) network, power and channel allocation must be carried out within the cognitive radio network so that no excessive interference is caused to any primary user. We are interested in spectrum-allocation/power-control schemes that maximize the spectrum utilization of the cognitive network while appropriately protecting primary users. While doing so, the control schemes must also meet the required signal to interference plus noise ratio (SINR) of each subscriber of the cognitive network. This problem can be formulated as a linear mixed (0-1) integer programming. Due to the high complexity in obtaining optimal spectrum-allocation/power-control schemes, we propose a suboptimal scheme that can be obtained at lower complexity while still achieving good spectrum utilization. This suboptimal scheme is constructed based on the idea of a dynamic interference graph that captures the interfering effects. Numerical studies of our control scheme are presented.

106 citations

Patent
11 Jan 2000
TL;DR: In this paper, a method for allocating traffic between multiple carriers in a wireless communications system measures loading on the communication system and selects an appropriate carrier from multiple carriers, based upon the loading measured.
Abstract: A method for allocating traffic between multiple carriers in a wireless communications system measures loading on the communication system and selects an appropriate carrier from multiple carriers, based upon the loading measured. A first carrier is selected if the load on the first carrier is lower than or equal to the lowest loading of any supplemental carrier among the multiple carriers. If the load on the first carrier is not lower, then the subscriber may be assigned either to a supplemental carrier or the first carrier. The carrier assignment of the subscriber depends upon a predetermined threshold, which preferably considers actual or estimated differential interference between the first carrier and the supplemental carrier.

106 citations

Journal ArticleDOI
TL;DR: This paper studies optimal bandwidth and power allocation in a cognitive radio network where multiple secondary users (SUs) share the licensed spectrum of a primary user (PU) under fading channels using the frequency division multiple access scheme.
Abstract: This paper studies optimal bandwidth and power allocation in a cognitive radio network where multiple secondary users (SUs) share the licensed spectrum of a primary user (PU) under fading channels using the frequency division multiple access scheme. The sum ergodic capacity of all the SUs is taken as the performance metric of the network. Besides the peak/average transmit power constraints at the SUs and the peak/average interference power constraint imposed by the PU, total bandwidth constraint of the licensed spectrum is also taken into account. Optimal bandwidth allocation is derived in closed-form for any given power allocation. The structures of optimal power allocations are also derived under all possible combinations of the aforementioned power constraints. These structures indicate the possible numbers of users that transmit at nonzero power but below their corresponding peak powers, and show that other users do not transmit or transmit at their corresponding peak powers. Based on these structures, efficient algorithms are developed for finding the optimal power allocations.

106 citations

Journal ArticleDOI
G.J. Foschini1, Z. Miljanic2
TL;DR: In this paper, the authors simulate call performance for users accessing channels in a regular cellular array with a base located at the center of each hexagon, and show that distributed power control and channel access can be combined in an access management policy that achieves satisfactory system capacity and provides desired call performance.
Abstract: Local autonomous dynamic channel allocation (LADCA) including power control is essential to accommodating the anticipated explosion of demand for wireless. The authors simulate call performance for users accessing channels in a regular cellular array with a base located at the center of each hexagon. The computer model includes stochastic channel demand and a propagation environment characterized by attenuation with distance as well as shadow fading. The study of LADCA shows that distributed power control and channel access can be combined in an access management policy that achieves satisfactory system capacity and provides desired call performance. The authors report: LADCA/power control is observed to be stable alleviating a major concern about users unaware of the signal to interference problems their presence on a channel might cause to others. There can be substantial inadvertent dropping of calls in progress caused by originating calls. Modeling user time dynamics is essential. LADCA contrasts very favorably with fixed channel allocation (FCA) in a comparative example. >

105 citations

Proceedings ArticleDOI
16 Apr 1990
TL;DR: The concept of equivalent bandwidth of bursty traffic sources is investigated and the superposition of two heterogeneous bursty classes is analyzed, showing the equivalent bandwidth independence of the average burst length and of the queue length.
Abstract: The concept of equivalent bandwidth of bursty traffic sources is investigated. The equivalent bandwidth measure depends on the source characteristics, the grade of service, and the interaction with the other type of traffic multiplexed on the same data link. The behavior of the statistical multiplexer is analyzed with inputs consisting of homogeneous bursty sources. The values of the equivalent bandwidth are analyzed for fixed statistical characteristics of the bursty sources and a fixed grade of service, and as a function of a background stream load. By assuming that the peak rate of the sources is sufficiently lower than the link rate (e.g. 1/15) and that the average burst length is greater than the queue length, the equivalent bandwidth independence of the average burst length and of the queue length is shown by simulation. The superposition of two heterogeneous bursty classes is analyzed. >

105 citations


Network Information
Related Topics (5)
Wireless network
122.5K papers, 2.1M citations
95% related
Wireless ad hoc network
49K papers, 1.1M citations
94% related
Network packet
159.7K papers, 2.2M citations
94% related
Wireless
133.4K papers, 1.9M citations
92% related
Fading
55.4K papers, 1M citations
91% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202315
202259
2021181
2020268
2019293
2018292