Method and device for eliminating NLOS of wireless honeycomb network

Abstract

The method discloses a method for eliminating NLOS in a wireless cellular network. The method comprises the following steps: a) values of TDOA are measured for N times; b), the mean value of N measured values of TDOA is calculated; c), a virtual starting point is set, so that N groups of values that signals of the neighbor base station and the serving base station reach the time delay; d) standard deviations of time of signal arrival of the neighbor base station and the serving base station are respectively calculated through the N groups of time delay values of the neighbor base station and the serving base station, thereby obtaining the mean value of errors of neighbor base station and serving base station signals NLOS; e), the TDOA mean value obtained in step b) minus the mean value of errors of the neighbor base station signals, and plus the mean value of errors of the serving base station signals, so as to obtain TDOA of line-of-sight propagation after the elimination of NLOS; and f), the TDOA value which is obtained in step e), used for eliminating NLOS error impact and reconstructed, is sent for positioning through a localization algorithm. The method of the invention ensures that the NLOS errors in TDOA can be effectively eliminated; and the TDOA after reconstruction can is close to the actual TDOA value in range of visibility. Therefore, the location estimated through the localization algorithm is closer to the actual location.

Description

technical field [0001] The present invention relates to a method for eliminating NLOS in a wireless cellular network to improve positioning accuracy, in particular to a method for eliminating the influence of NLOS in a Worldwide Interoperability for Microwave Access (Wimax) network to improve positioning accuracy. Background technique [0002] The international research and application of wireless positioning technology began with the automatic vehicle location (AVL) system in the 1960s, and then this technology was used in limited areas such as public transportation management, cargo transportation, taxi management, crime tracking and emergency medical services. has been applied within the scope. Since the 1980s, with the need for intelligent transportation systems (ITS) and the emergence of cellular mobile communication systems, new requirements have been placed on wireless positioning technology, which has attracted more researchers' interest. The US Federal Communicatio...

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Problems solved by technology

The Wylie method needs to know the prior information in the LOS environment, which is not feasible for the actual cellular network system; the gradient method has the disadvantages of slow convergence speed and may converge to a local optimum; The NLOS error can significantly suppress the effect, but this method requires the terminal to receive multiple BS signals to eliminate NLOS more accurately, which is also a strict requirement for the actual system. At the same time, the high computational complexity is also a major problem of the algorithm. question

Moreover, through simulation we found that these methods have limited ability to improve positioning accuracy, such as figure 1 As shown, these methods of eliminating NLOS can improve the positioning accuracy by about 10%, but this is far from meeting the requirements of E-911, which requires us to consider better methods of eliminating NLOS

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