Reliable TOA and TDOA Location Estimation Under Multipath Fading Channel Conditions in Wideband Wireless Networks for Indoor Factory Applications

Abstract Finding the reliable locations of radio devices using spatially separated sensor nodes (knows as “anchor nodes” whose positions are known in advance) is an important issue in the next-generation radio networks. The existing state-of-the-art localization techniques based on received signal strength (RSS), time of arrival (TOA) and time difference of arrival (TDOA) are suffering from inaccurate measurements due to multipath signals, interference, noise, lack of clock synchronization, high power consumption, and computational complexity. This paper presents a highly accurate and simplified versions of TOA, TDOA-based localization techniques that suit the resource constraint applications of industrial internet of things (IIoT) and towards 6G communication systems. The proposed TOA, TDOA techniques are based on orthogonal frequency division multiplexing (OFDM) channel estimation that ensures less susceptible to multipath effects, independent of synchronization errors, and reliable location estimations. Simulations were conducted using fast Fourier transform (FFT) and multiple signal classification (MUSIC) spectrum analysis methods at higher frequency bands under noisy environments and results were compared with the performance under ideal conditions. The localization accuracies are presented in terms of root mean square (RMS) errors for different noise figures, bandwidths, and their performance is analysed. The results proved that both the simplified versions of TOA and TDOA based localization provide accurate location values of sensor nodes even in noisy environments, and they are very close to the actual location values.