Abstract: A method for indirect communication in a WiMAX network includes: determining a wireless broadband terrestrial transmission scheme by a base station; transmitting, in response to the wireless broadband terrestrial transmission scheme, a first preamble and a first data frame, by a first set of relay stations, towards multiple subscriber devices, substantially simultaneously; and transmitting, in response to the wireless broadband terrestrial transmission scheme, a second preamble and a second data frame by another relay station towards other subscriber devices. Wherein a coverage area of the other relay station does not substantially overlap a coverage area of any of the first set of relay stations.

Abstract: Terminal transmission method and the received signal model are used to develop two methods that estimate the starting time vicinity associated with a random access channel (RACH). First of said methods, called In*Qn RACH starting time vicinity estimation (STVE), multiplies the In and Qn branches of a sample and exacts the starting time of a preamble signal from the peak output of the phase metrics expression (for both even and odd periodicity). The second method, called (In+jQn)2 RACH STVE, performs a square operation on the received complex signal and calculates the peak output of the corresponding phase metric to extract the exact starting time of a preamble signal.