Method and apparatus for uplink carrier frequency synchronization and antenna weight vector estimation in OFDMA system having smart antenna

A method for uplink carrier frequency synchronization and antenna weight vector estimation in an OFDMA system having a smart antenna, the method comprising the steps of:

• a) estimating carrier frequency offsets using training symbols in the frequency domain that are obtained by applying an FFT algorithm with respect to training symbols received during two slots within a training symbol transmission interval;
• b) compensating carrier frequency offsets of training symbols in the time domain received after the two slots based on the estimated carrier frequency offsets;
• c) estimating an antenna weight vector using the training symbols in the frequency domain that are obtained by performing an FFT algorithm with respect to training symbols in the time domain derived by compensating the carrier frequency offsets;
• and
• d) repeatedly performing said steps a) to c) during the transmission of the training symbols.

A method for uplink carrier frequency synchronization and antenna weight vector estimation in an OFDMA system having a smart antenna, the method comprising the steps of:

• a) receiving and storing training symbols in the time domain transmitted to estimate an antenna weight vector during a part of a training symbol transmission interval;
• b) estimating carrier frequency offsets using training symbols in the frequency domain that are obtained by performing an FFT algorithm with respect to the training symbols received during the part of training symbol transmission interval;
• c) compensating carrier frequency offsets of the stored training symbols in the time domain based on the carrier frequency offsets estimated at said step b);
• d) estimating an antenna weight vector using training symbols in the frequency domain that are obtained by using an FFT algorithm with respect to the training symbols in the time domain derived by compensating the carrier frequency offsets at said step c) during the part of training symbol transmission interval;
• e) estimating carrier frequency offsets using training symbols in the frequency domain that are obtained by performing an FFT algorithm with respect to training symbols received during two slots within the training symbol transmission interval;
• f) compensating carrier frequency offsets of training symbols in the time domain received after the two slots based on the carrier frequency offsets estimated at said step e);
• g) estimating an antenna weight vector using training symbols in the frequency domain that are obtained by carrying out an FFT algorithm with respect to the training symbols in the time domain compensated at said step f);
• and
• h) repeatedly performing said steps e) to g) during the residual training symbol transmission interval.

An apparatus for uplink carrier frequency synchronization and antenna weight vector estimation in an OFDMA system having a smart antenna, the apparatus comprising:

• a training symbol storing means for receiving and storing training symbols in the time domain transmitted from a terminal to estimate an antenna weight vector during a training symbol transmission interval;
• a carrier frequency offset estimation means for estimating carrier frequency offsets using training symbols in the frequency domain that are obtained by performing, at an FFT means, an FFT with respect to training symbols received during the training symbol transmission interval;
• a carrier frequency offset compensation means for compensating carrier frequency offsets of the training symbols in the time domain stored in the training symbol storing means based on the carrier frequency offsets estimated at the carrier frequency offset estimation means;
• the FFT means for performing an FFT algorithm with respect to the training symbols received during the training symbol transmission interval and the training symbols in the time domain compensated at the carrier frequency offset compensation means;
• and
• an antenna weight vector estimating means for estimating an antenna weight vector using the training symbol in the frequency domain that are obtained by performing an FFT algorithm with respect to the training symbols in the time domain compensated at the carrier frequency offset compensation means during the training symbol transmission interval.

An apparatus for uplink carrier frequency synchronization and antenna weight vector estimation in an OFDMA system having a smart antenna, the apparatus comprising:

• a carrier frequency offset estimation means for estimating carrier frequency offsets using training symbols in the frequency domain that are derived by performing, at an FFT means, an FFT with respect to training symbols received during two slots within a training symbol transmission interval;
• a carrier frequency offset compensation means for compensating carrier frequency offsets of training symbols in the time domain received after the two slots based on the carrier frequency offsets estimated at the carrier frequency offset estimation means;
• the FFT means for performing an FFT algorithm with respect to the training symbols in the time domain compensated at the carrier frequency offset compensation means an antenna weight vector estimation means for estimating an antenna weight vector using the training symbols in the frequency domain obtained at the FFT means;
• and
• means for repeatedly performing the carrier frequency offset estimation means, the carrier frequency offset compensation means, the FFT means, and the antenna weight vector estimation means during the transmission interval of the training symbols.