Patent ID: 8223743

Claim:
A method for reducing interchannel interference in a femtocell network within a coverage area of a macrocell network, the macrocell network and the femtocell network being both orthogonal frequency division multiple access (OFDMA) systems, the method comprising: using a correlation metric, determining arrival times of signals from mobile users of the macrocell network received at a base station of the femtocell network including determining a first arrival time for a first arriving one of the signals from the mobile users and determining a last arrival time for a last arriving one of the signals from the mobile users; determining whether a delay between the first arrival time and the last arrival time is greater than a cyclic prefix (CP) period for the femtocell network; and synchronizing transmission times by users of the femtocell network based on a synchronization point derived according to the determined arrival times, wherein the synchronization point equals the first arrival time if the arrival times fall within the CP period and wherein the synchronization point equals the first arrival time plus an additional delay derived from the correlation metric.