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In this paper, a teletraffic analysis method based on channel holding time statistics for new and handoff calls for system level performance evaluation of mobile cellular networks with link unreliability is developed. Firstly, mathematical expressions for the probability distribution function of channel holding time for new and handoff calls are derived considering different phase-type distributions...
A two-user decision making game is studied in the OFDM based subscriber cooperative relaying network, in which subscribers transmit their own data in the first phase, while helping to retransmit their partner's or choosing to freeride in the second phase. In the paper, we study a hierarchical game (HG) for a two user coalition, where cooperation is preferred and total payoff is transferable. Instead...
This paper considers power allocation in spatially-correlated dual-hop multiple-input multiple-output (MIMO) relay channels under power constraint for each hop channel. The proposed scheme allocates the transmit power considering the spatial correlation as well as the average signal-to-noise ratio (SNR) of dual-hop MIMO relay channels. By means of upper-bound analysis, the proposed scheme can minimize...
Cognitive radio technology has arisen as a hot topic in wireless communication in recent years. Special spectrum allocation algorithms are essential to adapt to the time-space varying characteristics of wireless spectrum in cognitive networks. In this paper, we study and simulate the guard channel policy proposed by Huang Zhen, etc. We find that the blocking probability of secondary users is relatively...
Different to orthogonal frequency division multiplexing using cyclic prefix (CP-OFDM), time division synchronous OFDM (TDS-OFDM) employs pseudo noise (PN) sequence as the prefix. TDS-OFDM provides better power efficiency than CP-OFDM since the PN prefix can be used for channel estimation while CP-OFDM needs dedicated pilot symbols. However, when TDS-OFDM is considered with frequency domain multiple...
Resources allocation of OFDM system is a key factor that affects system performance. Parteek Bansal proposed a bit-power allocation algorithm under different bit error rate (BER). But the process of its bit allocation will cause high complexity and bad real-time to build a power-increment table. In this paper, a low-complexity multi-user subcarrier-bit-power allocation algorithm for wireless OFDMA...
An adaptive resource allocation scheme is proposed for regenerative relay-based orthogonal frequency division multiplexing access systems. This scheme allocates subchannels to guarantee fairness between users, and also saves energy by minimising the transmission power. The subchannel allocation for data rate fairness is considered between direct link users and relay stations in the first time subslot...
Among the major challenges in the development of effective dynamic spectrum access techniques are the realization of the control channel, the detection of primary users, and the efficient use of the available spectrum. Most of the previous work in this field has addressed only a subset of these issues. In a previous paper we proposed a distributed multi-channel medium access strategy based on a network...
Opportunistic scheduling and rate-adaptation mechanisms exploit the variations in the channel states experienced by different users through the allocation of resources to users with better channel quality. Opportunistic scheduling has been considered in various contexts, typically with the assumption that rate adaptation and channel reassignment can be implemented with no delay, based on the instantaneous...
This paper considers a simple wireless network - the multiple relay channel (MRC) - wherein a single source communicates with a single destination with the aid of M parallel relays. The links between the communicating nodes are non-interfering and subject to erasures. The capacity of this network is derived under the assumption that the destination has access to perfect side information on the erasure...
We utilize axiomatic bargaining theory to depict certain implications of continuity properties of resource allocation strategies in wireless systems. Feasible utility sets are characterized as sub-level sets of interference functions. The collective choice function is used to represent resource allocation strategies. We use an axiomatic framework to emulate certain desirable properties of resource...
The two-way relay channel (TWRC) describes the communication between two terminals sharing a common relay. In this work we compare different protocols for the TWRC with a half-duplex relay (forwarding and protocol I) and transmission schemes (network coding relaying with random binning and XOR precoding), when the relay works in decode-and-forward and without channel state information at the transmitters...
We investigate a delay minimization problem in a multiple access wireless communication system. We consider a discrete-time non-fading additive white Gaussian noise (AWGN) multiple access channel. In each slot, bits arrive at the transmitters randomly according to some distribution, which is i.i.d. from user to user and from slot to slot. Each transmitter has an average power constraint of P. Our...
In this paper, we address the problem of spectrum sharing where competitive operators coexist in the same frequency band. First, we model this problem as a strategic non-cooperative game where operators simultaneously share the spectrum according to the Nash equilibrium (N.E). Given a set of channel realizations, several Nash equilibria exist which renders the outcome of the game unpredictable. For...
We consider the estimation of a Gaussian source by a Gaussian sensor network where L distributed sensors transmit noisy observations of the source through a Gaussian multiple access channel to a fusion center. In a recent work, Gastpar showed that for a symmetric sensor network with no fading, analog (uncoded) transmission achieves the optimal performance theoretically attainable (OPTA). In this work,...
Using multiple channels and smart frequency reuse strategy could significantly improve the performance of wireless sensor networks. In this paper we propose an method to determine channel usage based on discrete particle swarming optimization (PSO) algorithm. In stead of searching for a collision-free channel assignment which is not achievable in many scenarios, the goal of our algorithm is to find...
The broadcast problem including the plan design is considered. The data are inserted and numbered at predefined order into customized size relations. The server ability to create a full, Regular Broadcast Plan (RBP) with single and multiple channels after some data transformations is examined. The Regular Geometric Algorithm (RGA) prepares a RBP and enables the users to catch their items avoiding...
In this paper, distributed power allocation schemes are studied for amplify-and-forward (AF) cooperative relay networks, where only partial channel state information (CSI) is available at the source and relays. Aiming at minimizing the total transmit power while providing a target outage probability, a scheme is first investigated in which the source decides transmit power and a relay-forwarding threshold,...
This paper studies resource allocation problem in downlink multiuser orthogonal frequency division multiple access (OFDMA) system. The problem is formulated as sum-rate (cell throughput) maximization problem with strict data rate constraints imposed by the users and peak power constraint by the base station. We discuss the feasibility of the problem and propose two algorithms when the feasibility...
Soft handoff in CDMA cellular system increases system capacity as compared to hard handoff as interference is reduced by transmitting signals as lower power level. A CDMA cellular system involving integrated voice and data calls is considered in this paper. The developed model is based on priority reservation for handoff voice and data calls along with call queuing scheme for handoff data calls. Upper...
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