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Elastic Optical Network (EON) architecture has been proposed as a promising technology for a new generation of OFDM networks. It is based on the concept that spectrum can be split into smaller slices than are used currently in the fixed-grid network. It allows better spectral utilization and support for bit rates over 100 Gb/s. EONs arise with the problem of routing and spectrum allocation (RSA)....
The cross-entropy (CE) method was proposed to estimate the probability of rare events. Afterwards, it was applied to solve combinatorial optimization problems. This paper presents a CE-based method that adaptively allocates sub-carrier, bit, and power in orthogonal frequency division multiple access systems to obtain minimum total transmit power under given quality of service requirements, that is,...
Radio resource management in multi-user LTE networks is considered in this paper. Subject to a transmission power constraint, genetic algorithm is firstly investigated to optimize the system transmission rate. However, result shows genetic algorithm has the flaws of slow convergence rate and cannot reach to the theoretical maximum transmission rate. Aiming at this point, ant colony algorithm (ACA)...
This paper considers the scheduling and resource allocation with adaptive modulation in downlink coordinated multi-point transmission (CoMP) systems, where multiple users are served via zero-forcing precoding simultaneously by several cooperative base stations (BSs). The joint scheduling and resource allocation to maximize the sum rate is formulated as a combinational optimization problem under constraints...
a power allocation algorithm with Niche Genetic Algorithm in OFDM-MIMO 802.11n channel is proposed to optimize the total power with the precondition of guaranteed transmission speed. The simulation results show that the channel which is optimized by the Niche Genetic Algorithm can get the better power allocation proportion in shorter time. Meanwhile, it also significantly decreases the bit error rate...
Nowadays, the spread of wireless applications has led to the need of new spectrum resources and to the need to exploit in a more dynamic and efficient way those already in use. Several recent research works have confirmed the presence of unused spectrum portions in the range 30 MHz-3 GHz. As a consequence, developing new techniques to assure the utilization of these unused resources has become a key...
Broadband power-line communication (BPLC) is recognized as an attractive method for access networks and the orthogonal frequency division multiplexing (OFDM) with dynamic resource allocation is the key technology in combating with the multi-path fading and time-varying characteristics of power line channel. With the goal of fairness in bandwidth and maximum total throughput for all the users, a novel...
Subcarrier and bit allocation has been extensively investigated in the literature to improve the spectral efficiency of multiuser OFDM systems. However, most of the earlier studies using genetic algorithms (GA) focused on single-class service and users of best effort data rate. In this paper, a novel GA method which allocates subcarriers and bits to rate guaranteed users is presented. As the reproduction...
Adaptive resource allocation is one of the most challenging tasks for multiuser orthogonal frequency division multiplexing (OFDM) systems. In this paper, two evolutionary approaches, genetic algorithm (GA) and particle swarm optimization (PSO) have been applied for adaptive subcarrier and bit allocations to minimize the overall transmit power of a multiuser OFDM system. Each user will be assigned...
We propose a novel distributed cross-layer optimization approach for cognitive radio wireless networks. A cognitive radio is a wireless device that is capable of sensing the prevailing environmental conditions and automatically adapting its operating parameters in order to enhance the performance of both the system and potentially the whole network. Given the lack of a centralized intelligence to...
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