High Resolution Timing Advance Estimation Based on PRACH

摘要

Systems, methods and computer software are disclosed for providing high resolution timing advance estimation based on Physical Random Access Channel (PRACH). An example method includes receiving a preamble signal r(n) having a predetermined sampling frequency and a predetermined length; correlating a down sampled version of the received preamble with a reference preamble sequence c(n) using an FFT method to provide correlation output Ryc; using a peak value P of the correlation output Ryc to detect a preamble ID and a timing advance at a resolution of 24Ts; zero padding sequences Y(k) and C(k) so that they have a predetermined length resulting in sequences Y_hat(k) and C_hat(k), which are 1024-point FFT of y(n) and c(n); performing a maximum likelihood estimation (MLE) to estimate a timing offset; and detecting a peak value out of the R_hat(m) and using a corresponding index Q to provide a timing advance with an accuracy of 2Ts.