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.

Asynchronous Iterative Waterfilling for Gaussian Frequency-Selective Interference Channels: A Unified Framework

Abstract: In this paper we give an overview of recent results on the rate maximization game in the Gaussian frequency- selective interference channel. We focus on the competitive maximization of information rates, subject to global power and spectral mask constraints. To achieve the so-called Nash equilibrium points of the game Yu, Ginis and Cioffi proposed the sequential Iterative Waterfilling Algorithm (IWFA), where, at each iteration, the users choose, one after the other, their power allocation to maximize their own information rate, treating the interference generated by the others as additive colored Gaussian noise. To overcome the potential slow convergence of the sequential update, specially when the number of users is large, the simultaneous IWFA was proposed by the authors, where, at each iteration, all the users update their power allocations simultaneously, rather than sequentially. Recently, the authors showed that both the sequential and the simultaneous IWFAs are just special cases of a more general unified framework, given by the totally asynchronous IWFA. In this more general algorithm, the users update their power spectral density in a completely distributed and asynchronous way. Furthermore, the asynchronous setup includes another form of lack of synchronism where the transmission by the different users contains time and frequency synchronization offsets. A unified set of convergence conditions were provided for the whole class of algorithms obtained from the asynchronous IWFA. Interestingly, there is a key result used in the proof of convergence of the algorithms: an alternative interpretation of the waterfilling operator as a projector.

Prospect Pricing in Cognitive Radio Networks

Abstract: Advances in cognitive radio networks have primarily focused on the design of spectrally agile radios and novel spectrum sharing techniques that are founded on expected utility theory (EUT). In this paper, we consider the development of novel spectrum sharing algorithms in such networks taking into account human psychological behavior of the end-users, which often deviates from EUT. Specifically, we consider the impact of end-user decision making on pricing and management of radio resources in a cognitive radio enabled network when there is uncertainty in the quality of service (QoS) guarantees offered by the service provider (SP). Using prospect theory (a Nobel-Prize-winning behavioral economic theory that captures human decision making and its deviation from EUT), we design data pricing and channel allocation algorithms for use in cognitive radio networks by formulating a game theoretic analysis of the interplay between the price offerings, bandwidth allocation by the SP, and the service choices made by end-users. We show that, when the end-users under-weight the service guarantee, they tend to reject the offer, which results in under-utilization of radio resources and revenue loss. We propose prospect pricing, a pricing mechanism that can make the system robust to decision making and improve radio resource management. We present analytical results as well as preliminary human subject studies with video QoS.

Channel allocation and release for packet data services

Abstract: A telecommunications system (18) comprises a control node (24) and a base station node (22). The control node (24) maintains a first list (42) of idle radio channels which is consulted in order to obtain channels for a first type of telecommunications service. A second list (56) of idle radio channels is maintained for a specialized telecommunications service, the idle radio channels of the second list being radio channels which are unallocated with respect to the specialized telecommunications service but yet activated (e.g., having an established transmission path and synchronization). The second list of idle radio channels is initially consulted in order to obtain channels for the specialized telecommunications service. If no channels are available for the specialized telecommunications service on the second list, idle channels from the first list are adapted and utilized for the specialized telecommunications service. The specialized telecommunications service preferably involves packet data transfer (e.g., GPRS). As one aspect of the invention, any potential capacity problem is addressed by providing timers for channels on the second list. There is one timer corresponding to each channel on the second list, which timer is started when there is no more traffic ongoing on that channel. The channel remains activated with respect to the specialized telecommunications service, which makes fast specialized service access possible for all such users in that cell. As long as the timer has not expired, the channel on the second list is available for specialized service traffic without any new activation. However, when the timer expires, the channel is released and put on the first list, where it is once again available for all traffic. The timer values can be dynamically adjusted or varied, e.g., depending on processor load or traffic load at a cell.

Interference management in OFDMA Femtocell systems using Fractional Frequency Reuse

Abstract: This paper presents an interference management scheme for OFDMA Femtocell systems. Femtocell is recently introduced for indoor coverage extension. However, interference problem between the femtocell and the macrocell should be solved in advance. In this paper, we propose an efficient interference management scheme in the OFDMA femtocell systems using Fractional Frequency Reuse (FFR) in order to minimize the interference between both cells. Under the pre-allocated frequency band within a macrocell through the FFR optimally, the proposed scheme allocates sub-bands the femtocells efficiently to consider macrocell having a priority over femtocells and total/edge throughputs. Simulation results show that proposed scheme enhances the throughputs performance in overall network, especially for the macrocell users and cell edge users.

A performance bound on dynamic channel allocation in cellular systems: equal load

Abstract: We model a cellular network as a more general multiple service, multiple resource system. We define the "state" of the system as the number of calls currently carried in each cell. We restrict ourselves to channel allocation policies that place restrictions on the global state of the system, are allowed immediate global channel reallocation, and ignore handoffs. Maximum packing and fixed allocation are considered as special cases of such policies. Under uniform load conditions, we prove that throughput is increasing and concave with respect to increases in load or capacity, under maximum packing or fixed allocation. We propose that the optimal policy, in the considered class, varies from maximum packing at low loads to fixed allocation at high loads. This policy is often impractical to implement, but can be considered as a performance bound on practical systems. The analytical results are investigated numerically using a simple seven cell linear network. >