DIRECT POSITION ESTIMATION APPROACH OUTPERFORMS CONVENTIONAL TWO-STEPS POSITIONING

GNSS receivers compute its position by a two-steps pro- cedure. First, synchronization parameters are estimated and, then, a geometrical problem is solved to obtain re- ceiver's position. This is the approach typically taken due to its simplicity and modularity. However, recent results pointed out the potential pitfalls of such ap- proach. In that vein, Direct Position Estimation arise as a potential alternative, computing receiver's position di- rectly from the digitized GNSS signal. The latter is per- formed as a single-step procedure, obtaining the Maxi- mum Likelihood estimate of position. We base on a re- cent result to show that the variance of the single-step estimator is lower than the variance of the conventional two-steps estimation of position. The result is validated by computer simulations, comparing the performances of both alternatives.