The Key Technology Research About The Range Accuracy Adaptation Of Network Navigation

The rapid development of mobile communication technology has promoted the positioning and navigation services. As the positioning paradigm based on the cognitive radio network, because of its cognitive function and collaborative function, the network navigation has a superior performance than conventional positioning system. The cognitive positioning system(CPS) provides the theoretical support for realizing the range accuracy adaptation of network navigation, and it can adaptively adjust the system parameters under different scenarios. And, apparently, it depends on the research of the positioning awareness, spectrum sensing, environmental sensing and other relevant technologies. The study about the CPS will not only promote the progress of network navigation, but also facilitate the optimization and management of future network. On account of these, the thesis studies a series of relevant technologies after the analysis of the range accuracy adaptation algorithm process, which based on the structure of CPS. The following research results are the main contribution of the thesis:Firstly, this thesis combines both concepts of the wideband compressed spectrum sensing and the CPS. Because traditional wideband spectrum sensing technologies are not suitable for the CPS, the wideband spectrum sensing algorithm based on the compressed sensing is analyzed in this thesis. A new fusion reconstruction algorithm based on the orthogonal matching pursuit algorithm and the multipath matching puisuit algorithm is presented, which was applicated in the reconstruction of the sparse wideband spectrum. Simulation results show that the algorithm has good performance. Therefore, the wideband compressed spectrum sensing could be used as alternative technology of the CPS in the future.Secondly, the range accuracy adaptation model is useful for effectively selecting the best configuration parameter in the CPS. Through the analysis of Cramér-Rao Lower Bound(CRLB) based on time of arrival value, this thesis discusses the factors that influencing the range accuracy adaptation. And simulation results show that, the factors such as the system bandwidth, the signal-to-noise ratio(SNR) and modulation technique have significant influence on the range accuracy.Finally, in order to overcome the defect of the range accuracy adaptation model based on the CRLB, this thesis further proposes a new model, which based on the Ziv-Zakai Lower Bound(ZZLB). At the same time, by means of Karhunen-Loéve expansion theorem, the new model can provide more complete adaptive information compared with the CRLB. Consequently, it can be regarded as the supplementary information of the CRLB. It can be seen that the ZZLB provide a tighter error lower bound in low SNR region from the simulation results. And it also verified that the SNR, the system bandwidth and the observation time can all affect range accuracy. Obviously, these relevant researches provide more adequate theoretical foundation for the CPS.