Research On Resource Allocation Algorithm In Wireless Networks Based Pricing Theory

In recent years, with an increasing growth in wireless communication services, the resources (such as bandwidth, frequency, power, time, subcarrier and so on) of wireless networks become scarcer and scarcer, and more and more precious. How to efficiently allocate the resources of wireless networks is an open and long-term problem. Price theory provides a wealth tool to assign the resources of the market by using the price to process selection, competition and cooperation between the enterprises, which has been applied to allocate the resources of wireless networks. In this article, we use price theory to study the problem of how to allocate the resources in cooperative AF cell uplink, that in DF-based cooperative OFDM system, that in selfish multi-path multi-hop networks and that in wireless cell underlying D2D communication. The author's major contributions are outlined as follows:1. Price theory is applied to study the problem of joint resource allocation in cooperative AF wireless cell networks. In the system, each node can act as a source as well as a potential relay, and it is modeled as energy seller. Referring to price theory, the nodes which have less residual energy should charge a higher energy price, and vice versa. The objective of the system is to minimize total energy cost of all the nodes in wireless cell networks. A greedy-algorithm-based joint resource allocation algorithm is presented, which is divided into two parts:graphic-method-based optimal power allocation algorithm and greedy-algorithm-based relay selection algorithm. For a given source-relay pair, the optimal power is allocated to them by applying graphic method to minimize total energy cost in the first part. The relay with the least energy cost is selected to provide cooperation for each source in the second part. Simulations show that greedy-algorithm-based joint resource allocation algorithm can not only balance energy usage of the nodes in the system, but also prolong the network's lifetime and transmit more data than other algorithms.2. We apply price theory to study the problem of joint resource allocation in cooperative OFDM system with DF protocol. The model of cooperative OFDM system with DF protocol is formulated and its objective is to minimize total energy cost of all the nodes in the system. We obtain the solutions to the problem under two constraints:individual power constraint and sum power constraint. Under sum power constraint, dual method is applied to obtain the optimal solution and subgradient method is applied to search optimal dual point. To decrease computation overhead, a suboptimal greedy-algorithm-based scheme is presented to obtain a suboptimal solution which is divided into two parts.In the first part, graphic method is applied to obtain optimal power for a given subcarrier pair. And in the second part, a greedy-algorithm-based algorithm is presented to perform subcarrier pairing and relay selection. Under individual power constraint, dual method is also applied to obtain the optimal solution and subgradient method is applied to search optimal dual point. To decrease computation overhead, a suboptimal hybrid-hungarian-algorithm-based scheme is presented to obtain suboptimal solution which is divided into two parts. In the first part, graphic method is applied to obtain the optimal power for a given subcarrier pair. And in the second part, a hybrid-hungarian-algorithm-based algorithm is presented to perform subcarrier pairing and relay selection. Evaluations show that the two resource allocation algorithms proposed not only balanced energy usage of the nodes, but also prolong the lifetime of the system and transmit more data than that of other algorithms.3. Then auction theory is applied to study how to stimulate intermediate nodes to participate in cooperation by joint allocation of route and bandwidth in selfish multi-path multi-hop networks. The problem of joint route and bandwidth allocation in selfish multi-path multi-hop networks is modeled as auction game and mechanism design is performed. Theoretical analyses show that the proposed mechanism is strategy-proof Convex optimization theory is then applied to obtain the optimal solution. Least-cost-path-based bandwidth and route allocation algorithm is first presented for selfish networks with linear cost function and hybrid-water-filling bandwidth and route allocation algorithm is then presented for selfish networks with nonlinear cost function. Theoretical analyses show that Both of these bandwidth and route allocation algorithms are the optimal solutions to the system model. Simulations show that these two presented algorithms can both efficiently stimulate intermediate nodes to participate in cooperation, and hybrid-water-filling bandwidth and route allocation algorithm prevail over other algorithms in efficiency.4. The problem of joint resource allocation in wireless cell networks underlying D2D communications is studied in the last chapter. System model for wireless cell networks underlying D2D communications is formulated. Our objective is to minimize total interference of all the nodes to meet signal-to-noise requirement of each node in the networks. User equipment pairing and power control algorithm is then proposed, which is composed of two parts:the first one is graphic-method-based power control algorithm for a given pair of D2D user equipment and cell user equipment, and the second one is hybrid-hungarian-method algorithm to pair D2D user equipment with cell user equipment. Simulations show that the proposed use equipment pairing and power control algorithm can not only decrease total interference in wireless cell networks, but also permit more connections than other algorithms.