Dissertation > Industrial Technology > Radio electronics, telecommunications technology > Wireless communications

Resource Allocation in Future Broadband Wireless Communcations

Author ZuoYingLei
Tutor SongJunDe
School Beijing University of Posts and Telecommunications
Course Circuits and Systems
Keywords Collaborative communication Cognitive radio Infrastructure relay User relay Network coding Orthogonal frequency division multiplexing with multiple access Utility function
Type PhD thesis
Year 2011
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, Due to the shortage of radio resources in a wireless communication system, how to effectively become the core of one of the next generation wireless communication system scheduling and allocation of resources to meet the demand for communication services. Radio resource allocation and scheduling is a further expansion of channel capacity, to improve the communication quality of key technologies, optimize and improve the performance of a communication system having a superior and irreplaceable. In this thesis, the two key technologies for future wireless communication - collaboration transmission and cognitive radio topic ideas to improve network capacity, to increase the utilization of network resources, consider the system fair and meet different user's QoS business needs, optimization theory, game theory and market theory as the theoretical prototype of focus, depth to expand broadband wireless communication system resource allocation in the future. Mongolia a number of countries such as the 863, the National Natural Science Foundation of China and the International Science and Technology Cooperation project support of this thesis, the cut scene around collaborative communication system and cognitive radio systems analysis, in-depth study of the future broadband wireless communication technology resource allocation, and actively explore new solutions, the following research: (1) for OFDM two-hop relay cooperative system, proposed resource allocation algorithm suitable for multi-service QoS. Considering the QoS requirements of a variety of business models and different service scheduling fairness designing an adaptive the accumulated utility function (AU-function, Aggregated Utility Function) optimization goals; through joint relay selection and subcarriers, power distribution, improve system performance on the basis of guarantee the business QoS, user fairness. Simulation results show that the proposed algorithm in the system throughput, latency, packet loss rate, cache state performance has been improved, and the the AU function of cumulative form of beneficial optimized for different QoS metrics. (2) relay network design user cooperative transmission model for multi-user collaboration and propose a distributed hierarchical game (HG, Hierachical Game) algorithm analysis the user collaboration uplink transmission resource allocation algorithm. First, the multi-user network user pairing decomposed into multiple two-user cooperative transmission network the HG algorithm to solve the collaboration resource allocation problem. Hierarchical game model includes two game: Nash Game at the user level, using the two-user judgment Distributed to solve the problem of collaboration strategy selection, that is, \\Mentioned in the HG algorithm, mutual cooperation is mutual and total utility can be transferred, there is a unique Nash equilibrium. In addition, to further discuss the incentive factor, and prove that if the user is more concerned about the next time slot transmission and the appropriate power control, the user will select collaboration strategy. Therefore, if the price incentives (such as power, bandwidth, etc.), the selfish behavior of the users can get a better guide. The simulation results show that the proposed algorithm can collaborate by encouraging users to improve the transmission efficiency and good performance in bad single-user transmission system capacity and improve. (3) In order to improve the throughput of cooperative systems proposed an OFDMA full duplex cooperative relay transmission scheme based on network coding (NC, Network Coding), analysis of two classical performance evaluation under the program - the system capacity and outage probability, and gives the closed expressions. Compared to the direct transmission (DT, Direct Transmission) and the ordinary cooperative transmission (CT, Cooperation Transmission) mode, network coding based cooperative transmission (CT NC, Netwrok Coding based Cooperative Transmission) achieved 11.8% higher than CT mode chain Road capacity gain than the DT mode increased by 32.5% (SNR = 20 or so), outage probability is 50% lower than CT than DT reduce up to 100% (SNR = 5 or so). Seen, due to the network coding gain, CT_NC in system capacity and robustness than DT and CT have improved. At the same time, it is further proposed a two-layer Nash equilibrium (DL_NBS, Double Layer_Nash Bargaining Solution) algorithm to solve the resource allocation problem of full-duplex cooperative relay transmission scheme based on network coding, consider a balanced collaborative user throughput, respectively, through the sub-carrier the bargaining balance and power bargaining balanced coordination between the users of the subcarrier and power allocation. The simulation results show that the proposed DL NBS game resource allocation scheme, compared with the traditional resource allocation algorithm is not only more applicable to the distributed user collaboration scene, and can obtain the fairness and effectiveness of the compromise. (4) for spectrum sharing and competition issues, the introduction of the OODA cognitive ring to build a new kind of cognitive radio network spectrum sharing behavior analysis model. And on this basis, drawing on economic theory, proposed dual spectrum auction theory based on the utility function design competition program, based on the main network user behavioral characteristics of the spectrum management problem, taking into account the time-varying wireless channel , transmission forecast and spectrum trading history, in the judgment process is appropriate to introduce certain predictions and learning factors, were designed main utility function of times the user's decision-making, a clever solution to the problem of spectrum sharing between primary and secondary network. Based on the supply and demand relationship between the primary users and secondary users of the spectrum, consider two scenarios: the oversupply that more primary user (MPLS, More Primary Users Less Secondary User) and in short supply, ie times more users (LPMS, Less Primary Users More Secondary User) in the case of primary and secondary users interact with a specific process. At the same time, to solve the problem of spectrum sharing between primary and secondary network, raised the four auction bidding indicators all times within the network spectrum competition issues. Simulation results show that, the proposed algorithm can effectively solve the problem of spectrum sharing between primary and secondary network, four bid auction strategies have focused on the network within the spectrum competition issues in both the supply and demand relationship, and compared The traditional centralized cognitive access mode performance achieved comparable spectrum efficiency, and reduce the cost of network deployment, to facilitate the use of distributed autonomous transaction to achieve the purpose of spectrum sharing access. In addition, the to consider dynamic cognitive radio network intelligence, strategically modeling autonomous secondary users to access the available spectrum opportunities cognitive radio network is proposed based on the the Enhanced Learning Strategies double auction mechanism to deal with the primary and secondary users The spectrum access competition issues. Take into account selfish, opportunistic spectrum access limited and time-varying environmental changes and multi-user transmission needs, based bid mechanism and the main users enhanced learning strategies were designed to protect the price mechanism. The mechanism can affect the spectrum access between the primary and secondary users, all users of the current revenue and return. Historical resources have been allocated based on the observation of the behavior and state of the status quo and forecast future earnings, enhanced learning ways to gradually improve the protection of times the user's bidding strategy and the main user pricing strategy to achieve the best channel access strategy, thereby effectively to competitive spectrum opportunities. The simulation results show that the proposed based on enhanced learning strategy double auction algorithm can greatly improve the user's bidding strategy, user packet loss, bid efficient transfer rate performance have been greatly improved. In conclusion, the thesis for wireless resource allocation, two key technologies for future wireless communications, cooperative communication and cognitive radio at the physical layer based OFDM transmission, combined with optimization theory, game theory, mathematical theory to improve network capacity, network resource utilization and meet user fairness, different QoS business needs as the goal, consider cross-layer design thinking, in-depth study of a multi-channel, power, transmission time slots, frequency resource allocation. Cooperative communication and cognitive radio technologies in future wireless mobile communication and optimization theory exploratory study.

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