Improving the Tracking Accuracy of TDMA-Based Acoustic Indoor Positioning Systems Using a Novel Error Correction Method

To improve the tracking accuracy of moving target by the acoustic indoor positioning system (AIPS) using time division multiplexing access (TDMA) technology, a novel TDMA correction method is proposed. The main idea of the proposed method is to convert the movement of the target into the movement of the audio base station. Specifically, the base station is moved according to the estimated velocity so that the distance between the base station after being moved and the current target position is equal to the length of the path through which the audio emitted by the base station reaches the target, and then the coordinates of the base station after being moved are used for positioning, so as to realize the error correction. Both simulations and acoustic indoor moving target tracking experiments were conducted to evaluate the performance of the proposed method. The simulation results show that the tracking errors of TDMA-based AIPS on moving targets can be effectively corrected under the condition that the velocity and measurement noise meet the corresponding thresholds. In the moving target positioning experiments, compared with the positioning accuracy before correction, the positioning accuracy after correction is improved by about 0.20 m (90%) in TDMA-only transmission scheme and about 0.08 m (90%) in hybrid transmission scheme of TDMA and FDMA. The proposed method has an important application value in improving the tracking accuracy of TDMA-based AIPS for moving targets.