A Probability Density Based CSI Indoor AP Localization Algorithm

Abstract

The present invention provides a CSI indoor AP positioning algorithm based on probability density, divides the entire floor plan, and establishes a corresponding probability density table, the value of each grid in the table indicates the possibility of AP being in the corresponding grid; when in When a measurement point detects an AP to be located, OFDM technology is used to divide the channel into sub-channels of different frequencies, and the CSI value is collected on each sub-channel, and the RSSI value is added as an auxiliary; according to the CSI value and RSSI value described in S2 Calculate the possibility of AP falling in this room and add it to the probability density table; when all the measurement points complete the process of step S2‑S3, a final probability table will be obtained, in which the grid with the smallest average probability corresponds to The room is where the AP is located. The present invention selects CSI and RSSI as signals for indoor positioning, and the position of the receiving end is known to precisely locate the position of the AP in the wireless indoor system, which can effectively improve the precision and accuracy of positioning.

Description

technical field [0001] The invention belongs to the technical field of wireless network positioning, and in particular relates to a probability density-based CSI indoor AP positioning algorithm. Background technique [0002] In recent years, wireless communication technology has developed rapidly, and in wireless technology, location-based service is one of the most potential wireless network services. [0003] 1. Indoor positioning based on RSSI [0004] In an indoor environment, the transmission of wireless signals needs to be affected by various degrees such as diffraction, reflection, and refraction, so the wireless signals received by the receiving end are actually obtained through multi-path aggregation. Wireless signals on these different paths will have different degrees of delay, clipping and phase changes. The receiving end receives the combination of signals from these different paths at a certain moment, and this signal can be expressed as: [0005] [0006...

AI Technical Summary

Problems solved by technology

[0013] In indoor positioning based on signal strength, we cannot avoid the impact of multipath effects and noise interference on positioning performance. Although RSSI-based positioning technology is currently very common, after the previous introduction we can find that in complex In an environment where the signal strength is very unstable, it is impossible to distinguish whether the change in signal strength comes from the change of the environment or the interference caused by objects entering the environment, so the accuracy and accuracy of indoor positioning cannot be satisfied to a certain extent.

Images