RSSI-based positioning method for wireless sensor network

Abstract

The invention relates to an RSSI-based positioning method for a wireless sensor network, which comprises the following steps of: firstly, receiving a radio-frequency signal sent in a radio-frequency mode by a transmitting node through a receiving node in the wireless sensor network, then, demodulating and filtering the received radio-frequency signal subjected to multi-path fading to acquire a corresponding base band signal through the receiving node, over-sampling each code chip in the base band signal, performing related despreading on a first sampling point of each code chip to acquire bitinformation which is not subjected to multi-path interference in the chip, and finally, calculating the RSSI value according to the acquired bit information to determine the distance between the receiving node and the transmitting node so as to realize positioning. Therefore, the method is simple and easy to implement, and can reduce the influence of the multi-path interference on positioning.

Description

technical field [0001] The invention relates to the field of wireless sensor network positioning, in particular to an RSSI-based positioning method in a wireless sensor network. Background technique [0002] Wireless Sensor Network (WSN) is an "intelligent" network composed of miniature sensor nodes with wireless communication, perception and computing capabilities. It is used in various fields such as military, agriculture, environmental testing, medical and health, industry, intelligent transportation, etc. In wireless sensor network applications, the location information of nodes is very important. In most applications, the data sensed without knowing the sensor location is meaningless. At present, the sensor network positioning application mainly faces two main problems: one is the positioning accuracy, and the other is the positioning cost. The distance measurement based on RSSI (received signal strength indicator) has been widely used in the positioning of wireless s...

AI Technical Summary

Problems solved by technology

At present, the application of sensor network positioning mainly faces two main problems: one is positioning accuracy, and the other is positioning cost.

However, in actual ranging, the RSSI value is greatly affected by multipath interference, which reduces the accuracy of ranging and thus reduces the accuracy of positioning.

[0003] At present, the research on distance measurement is mainly divided into two aspects. On the one hand, it uses the RSSI value given by the communication chip to conduct a large number of actual environmental tests, and uses methods such as averaging, Gaussian model fitting, and differential calculations based on the fading channel model. Reduce the ranging error; on the other hand, it is to improve the RSSI algorithm of the physical layer. The IEEE802.15.4 standard does not authorize a specific method for measuring RSSI, but only specifies the time accumulation length of RSSI. , the RSSI value is obtained by accumulating signals with a length of 8 data bits. Some algorithms use FFT to estimate the channel and then calculate the RSSI value. There are also some algorithms that filter out singular signals and reduce instantaneous interference and noise interference through FIR and IIR filtering. However These algorithms do not consider multipath interference, and the RSSI values ​​obtained by them are all affected by multipath

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