LOW COMPLEXITY BANDWIDTH EFFICIENT CARRIER FREQUENCY OFFSET ESTIMATION TECHNIQUE FOR OFDMA UPLINK TRANSMISSIONS

摘要

A system and a method for estimating low complexity bandwidth efficient carrier frequency offset for orthogonal frequency division multiple access (OFDMA) and or single carrier frequency division multiple access (SC-FDMA) uplink transmissions in a communication network systems comprising a group of subscriber stations, a base station including carrier frequency offset unit, said method steps comprising:;transmitting plurality of null subcarrier signals and data subcarrier signals from plurality of said subscriber stations (SS) to the base station; processing said transmitted subcarrier signals at the base station by estimating carrier frequency offset (CFO) by means carrier frequency offset unit; selecting the subcarrier signals based on carrier assignment scheme (CAS); characterized in that said step of estimating carrier frequency offset comprising: generating a trial carrier frequency offset (CFO) vector thereafter point to point multiplying said trial carrier frequency offset (CFO) vector with the received signal vector without cyclic prefix; adding total energies of substantially all signals of designated null subcarrier locations; comparing added value of energies of substantially all signals of designated null subcarrier locations with previously stored null subcarrier energy to obtain a minimum energy if any corresponding to previous iteration; storing said minimum energy value against the trial carrier frequency offset (CFO) value; repeating the process until all the trial values are over; and identifying the trial carrier frequency offset (CFO) value corresponding to the minimum energy as the estimated carrier frequency offset.