Research On Key Technologies Of NGB-W System Based On Distributed Antennas

With the swift development of mobile communication technology, people expect to obtain communication services more rapidly. At the same time, the nation proposed a strategy officially to integrate the existing Internet, broadcast network and telecommunications network into a unified network. The next generation broadcast wireless network (NGB-W) is raised under this context to realize a wireless broadcast network which process bidirectional communication function. And distributed MIMO multiple antennas system has been employed to copy with the challenge of scarce spectrum resources in cellular mobile communication system. The key technologies of NGB-W system based on distributed antennas are studied in this thesis.Firstly, the fundamental principles of distributed MIMO multiple antennas, pre-coding, multimedia broadcast multicast service (MBMS) and coordinated multi-point in cellular mobile communication system are summarized. The novel network architecture of NGB-W system which is combined of the large cell and small cells is also researched.Secondly, the architecture of NGB-W system based on distributed antennas is analyzed. A large number of distributed antennas are used in each small cells in NGB-W system. The distributed MIMO channel modeling is studied, and the antenna transmitting power of downlink in distributed and centralized MIMO antenna system is researched. The computer simulation result shows that the property of average capacity and coverage of distributed antennas system can meet the requirements of NGB-W system.Thirdly, the downlink multi-uesr pre-coding technology of NGB-W system based on distributed antennas is analyzed. The traditional block diagonalization and maximum signal-to-leakage-and-noise ratio pre-coding schemes are investigated through simulation. Then vector perturbation and weighted pre-coding schemes based on the signal-to-leakage-and-noise ratio criterion are proposed to modify the drawbacks of the traditional pre-coding scheme. The simulation results show that the proposed schemes improve the system’s average symbol error rate and capacity performance.Finally, a group pre-coding scheme for multi-user multicast scenario in NGB-W network with low complexity is proposed based on distributed multiple antennas system. The simulation results show that the proposed scheme achieves satisfactory average symbol error rate performance with lower computational complexity and fewer resources.