Method and apparatus using cell-specific and common pilot subcarriers in multi-carrier, multi-cell wireless communication networks

A method performed by an orthogonal frequency division multiple access (OFDMA)-compatible base station that uses OFDMA subcarriers in a frequency domain and time slots in a time domain, the method comprising:

• transmitting in a cell and at a same time:
• cell-specific pilot OFDMA subcarriers, that carry cell-specific pilots corresponding to the cell, at a transmission power level that is higher than a transmission power level of data OFDMA subcarriers adjacent to each of the cell-specific pilot OFDMA subcarriers, wherein the transmission power level of the cell-specific pilot OFDMA subcarriers is selected based on the transmission power level of the data OFDMA subcarriers, and wherein the cell-specific pilot OFDMA subcarriers is fewer OFDMA subcarriers than all OFDMA subcarriers transmitted in the cell;
• and
• the data OFDMA subcarriers adjacent to the cell-specific pilot OFDMA subcarriers;
• wherein the cell-specific pilots corresponding to the cell are different than second cell-specific pilots corresponding to a second cell, and further wherein the cell-specific pilot OFDMA subcarriers are different than OFDMA subcarriers via which the second cell-specific pilots are transmitted;
• and
• wherein data OFDMA subcarriers are transmitted in a neighboring cell corresponding to the same OFDMA subcarriers as the cell-specific OFDMA subcarriers and the cell-specific OFDMA subcarriers are transmitted at a higher power level than the data OFDMA subcarriers transmitted in the neighboring cell.

An orthogonal frequency division multiple access (OFDMA)-compatible mobile station that uses OFDMA subcarriers in a frequency domain and time slots in a time domain, the OFDMA-compatible mobile station comprising:

• at least one antenna;
• and
• a receiver;
• and
• the at least one antenna and the receiver are configured to receive in a cell and at a same time:
• cell-specific pilot OFDMA subcarriers, that carry cell-specific pilots corresponding to the cell, at a transmission power level that is higher than a transmission power level of data OFDMA subcarriers adjacent to each of the cell-specific pilot OFDMA subcarriers, wherein the transmission power level of the cell-specific pilot OFDMA subcarriers is based on the transmission power level of the data OFDMA subcarriers, and wherein the cell-specific pilot OFDMA subcarriers is fewer OFDMA subcarriers than all OFDMA subcarriers transmitted in the cell;
• and
• the data OFDMA subcarriers adjacent to the cell-specific pilot OFDMA subcarriers;
• and
• the receiver is further configured to:
• recover cell-specific information using the cell-specific pilots;
• wherein the at least one antenna and the receiver are further configured to receive second cell-specific pilots corresponding to a second cell, wherein the cell-specific pilot OFDMA subcarriers are different than OFDMA subcarriers on which the second cell-specific pilots are received;
• and
• wherein data OFDMA subcarriers are received from a neighboring cell corresponding to the same OFDMA subcarriers as the cell-specific OFDMA subcarriers and the cell-specific OFDMA subcarriers are received at a higher power level than the data OFDMA subcarriers received from the neighboring cell.

A method performed by an orthogonal frequency division multiple access (OFDMA)-compatible mobile station that uses OFDMA subcarriers in a frequency domain and time slots in a time domain, the method comprising:

• receiving in a cell and at a same time:
• cell-specific pilot OFDMA subcarriers, that carry cell-specific pilots corresponding to the cell, at a transmission power level that is higher than a transmission power level of data OFDMA subcarriers adjacent to each of the cell-specific pilot OFDMA subcarriers, wherein the transmission power level of the cell-specific pilot OFDMA subcarriers is based on the transmission power level of the data OFDMA subcarriers, and wherein the cell-specific pilot OFDMA subcarriers is fewer OFDMA subcarriers than all OFDMA subcarriers transmitted in the cell;
• the data OFDMA subcarriers adjacent to the cell-specific pilot OFDMA subcarriers;
• recovering cell-specific information using the cell-specific pilots;
• and
• receiving second cell-specific pilots corresponding to a second cell, wherein the cell-specific pilot OFDMA subcarriers are different than OFDMA subcarriers on which the second cell-specific pilots are received;
• wherein data OFDMA subcarriers are received from a neighboring cell corresponding to the same OFDMA subcarriers as the cell-specific OFDMA subcarriers and the cell-specific OFDMA subcarriers are received at a higher power level than the data OFDMA subcarriers received from the neighboring cell.