| Summary: | 碩士 === 國立臺中教育大學 === 資訊科學系 === 100 === The Location-based service on Wireless Sensor Networks, mainly depend on the Receiver Signal Strength (RSS) to measure the distance between the sender and receiver. The location unaware sensor nodes send beacon periodically, which are captured by anchor sensor nodes. However, it is well-known that these systems suffer from big inaccuracy problems because of environmental changes (the ratio of anchor and target). In this thesis, two three-dimensional space-based location algorithms in wireless sensor network were introduced. The first location algorithm is “Single Mobile Anchor Location estimation algorithm” (SMAL). The second algorithm called “Secant Location Estimation Algorithm” (SLEA). Both location algorithms use single flying anchor that equipped a GPS receiver to coordinate itself position in unknown territory. The mobile anchor node is able to calculate the accuracy position of unaware location sensor nodes through the proposed location estimation flying model in the three-dimensional coordinate system. Simulation results show the percentage of location estimation error is around 0.04% in SMAL and 1% in SLEA. Therefore, the SMAL applicable to high accuracy and non-real time applications. The adaptability of the SLEA scheme for the variable communication range makes it more suitable for deployments in wide regions.
In real-life there are many wireless devices using the 2.4GHz ISM frequency band. However, the effect of co-channel interference will cause the deviation from the actual receive signal strength. Therefore, the measuring distance error will certainly affect the positioning results. In this thesis, different Bit Error Rate and adjustment Beacon Order has been investigation. Simulation results show that the SLEA scheme will achieve the higher positioning accuracy in error-prone channel condition when the value for Beacons Order (BO) equal to 3.
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