Research On Some Key Technologies Of Heterogeneous Cooperative Wireless Network

With the development of telecommunication technologies, the change of market requirements and the intensification of commercial competition, the mobile communication systems and broadband wireless access networks are evolving along their own direction of development direction rapidly, and gradually forming the heterogeneous wireless networks with the coexistence of multiple access technologies. In the meantime of heterogeneous networks are integrating, the cooperative relaying technique which can achieve distributed spatial diversity gain by forming virtual antenna arrays has been widely acknowledged as a promising technique. How to integrate the cooperative relaying network into the existing networks to increase the transmission data-rate, decrease the power consumption, and extend the coverage area is one of the most important issues to construct the future wireless communication networks. The environment of heterogeneous wireless networks is complicated, so the traditional radio resource management, mobility management and quality of service (QoS) management of single network can not support the cooperation between heterogeneous networks. How to realize the integration and cooperation between heterogeneous networks, conform the resource of separate networks, guarantee the continuity of communication while the mobile user moving between multiple networks, and improve the network performance and increase the efficiency of radio resource utility, is the technological challenge for the cooperative management of heterogeneous networks. This paper investigates some of the key technologies to improve the performance of heterogeneous cooperative wireless network, includes the radio resource management, conditional cooperative mechanism, cooperative network coding, and the cross-layer design of combining the adaptive modulation and coding together with hybrid ARQ. The simulation platform is established and the schemes and algorithms are validated using the simulation platform. The contribution of the paper is as follows:This paper proposed a mechanism to integrate heterogeneous networks through the cooperative relaying technique, which can satisfy the demand to take the infrastructure network as the main part and use the short distance wireless access networks as the complementarities, and this mechanism can extend the coverage area and improve the system capacity of traditional cellular network, and form the ubiquitous wireless access environment. In order to realize the integration and cooperation between different networks, this paper proposed a policy-based united radio resource management scheme, and gave the functional model and work principal of different parts. The proposed scheme operates from a common perspective that takes into account the overall amount of resources in the available networks, and ensures an efficient use of the available radio resources by means of joint access control and data scheduling. The proposed policy-based radio resource allocation algorithm provides a flexible approach for operators and network providers to deploy and correlate business strategies with the overall network actions. This paper also proposed the policy-based access network selection algorithm, policy-based vertical handoff algorithm, and policy-based end-to-end QoS management. The proposed algorithms provide the seamless handover and roaming between heterogeneous networks, and utilize the network resource after vertical handover effectively. Simulation results are presented to show the effectiveness of the proposed scheme and algorithms.In order to improve the system performance of cooperative relaying network, this paper analyzed the advantages and disadvantages of different cooperative relaying mode in cooperative relaying network. In order to solve the competition of radio resource between cooperative users, this paper proposed a distributed resource allocation algorithm based on non-cooperative game theory. Simulations are conducted to demonstrate the rationality, efficiency and fairness of sub-carriers and power allocation between cooperative users, and simulation results show the proposed algorithm can increase the system capacity and the efficiency of resource utilization.The heterogeneous wireless cooperative relay networks have received considerable interests in both academia and industry fields. The mechanism of cooperative relay selection is very essential for the design of heterogeneous wireless relay networks. In order to realize the advantage of selection diversity, this paper proposed a new relay selection mechanism called conditional relaying mechanism, based on the self-similar nature of network traffic in heterogeneous wireless cooperative relaying network. Compared to conventional relay selection mechanism, the proposed mechanism considers the traffic queue condition of the relay nodes rather than just comparing the signal-noise-ratio (SNR). The self-similarity nature of network traffic has been discovered to be a ubiquitous phenomenon in communication networks, and we combine some critical parameters of self-similar traffic to come up with some related results. The extensive simulations are conducted to show that the proposed scheme can significantly decrease the system outage probability.Network coding theory is an important break-through in network communication and development. The gateway nodes in network not only focus on simple store-and-forward, but also encode the information that pass by. Therefore, the coding has enlarged the capacity and stability of the entire network. Considering both the validity and the reliability of the system, this paper investigates the performance of the network coding cooperative system which combines both the network coding and the cooperation. The proposed scheme can significantly decrease the system outage probability and decrease the transmission power. Simulations are conducted to demonstrate the system performance of applying the network coding to the cooperative relaying network.An important aspect of wireless networks is the dynamic behavior. The conventional protocol structure is inflexible as various protocol layers can only communicate in a strict manner. In such a case, the layers are designed to operate under the worst conditions, rather than adapting to changing conditions. This leads to inefficient use of spectrum and energy. In this paper, we present the cross-layer design for adaptive modulation and coding (AMC) with HARQ. For each of two widely used HARQ technique chase combining and incremental redundancy, the close-form functions of average retransmission time, average delay and average throughput are derived for a specific modulation and coding scheme (MCS). Based on the derived functions, a novel MCS selection method is proposed. Simulation results show that the proposed scheme can significantly improve the TCP performance.In conclusion, this paper investigated the key technologies to improve the performance of heterogeneous cooperative wireless network, and proposed a mechanism to integrate heterogeneous networks through the cooperative relaying technique, and proposed the policy-based united radio resource management scheme. This paper also proposed the conditional relaying mechanism which considering the channel state and traffic queue condition, and investigates the performance of the network coding cooperative system which combines both the network coding and the cooperation, and presented the cross-layer design for AMC with HARQ. The proposed mechanism and algorithm realize the integration and cooperation between heterogeneous networks, conform the resource of separate networks, guarantee the continuity of communication while the mobile user moving between multiple networks, and improve the network performance and increase the efficiency of radio resource utility.