A modified version of the datagram capacity assignment of the FODA access scheme, named FODA/IBEA, is briefly presented. The main difference from the previous version (besides the fade countermeasure feature) is the possibility of the system to migrate, depending on the overall loading conditions, from a sort of fixed TDMA (called pre-assignment mode), in which each active station shares the sp...

-Many space-science experiments need an active isolation system to provide them with the requisite microgravity environment. The isolation systems planned for use with the International Space Station (ISS) have been appropriately modeled using relative position, relative velocity, and acceleration states. In theory, frequency-weighting design filters can be applied to these state-space models, ...

In this paper, we study the problem of resource allocation for a multiuser orthogonal frequency-division multiple access (OFDMA) downlink with eavesdropping. The considered setup consists of a base station, several users and a single eavesdropper that intends to wiretap the transmitted message within each OFDMA subchannel. By taking into consideration the existence of the eavesdropper, the base...

Abs t rac t . In this paper, we present the constraint handling techniques developed to tackle a real world optimization application: the frequency assignment problem (FAP) in cellular radio networks. The main goal of this application consists in finding assignments which minimize electromagnetic interference due to frequency reuse and minimize the number of frequencies used. An acceptable assi...

A novel generic distributed algorithm is presented, which assigns in a self organizing way resources to the cells in cellular networks under the constraints that resource restrictions need to be considered between the cells. The algorithm operates in a fully distributed way, running independently inside each base station without any central entity. It optimizes the resource assignment, is capab...

While heterogeneous cellular networks offer the potential to improve network performance by augmenting coverage and enhancing traffic capacity, resource allocation is extremely complicated due to the heterogeneous and unplanned nature of base station deployments. In this paper, we present SortingHat, a tractable optimization model which leverages the advantages of the different heterogeneous co...

------------------------------------------------------------------ABSTRACT-------------------------------------------------------------------Coding-based solutions for MANETs have emerged as a basic solution to current high rate data accessing in adhoc network. This has become essential related to the absence of centralized control such as a monitoring station. A code assignment protocol is nee...

A joint code division multiple access and noncollision packet reservation multiple access (CDMA/NC-PRMA) technique is proposed and investigated as an uplink protocol for the third-generation (3G) mobile systems. Being the underlying time division multiple access (TDMA) architecture of the CDMA transmissions, NC-PRMA enables the base station (BS) to have a centralized control over the slot alloc...

Link capacity is defined as the number of channels available in a link. In direct-sequence code-division multipleaccess (DS-CDMA) cellular systems, this is limited by the interference present in the link. The interference is affected by many environmental factors, and, thus, the link capacity of the systems varies with the environment. Due to the varying link capacity, static channel assignment...