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

A method of generating transmission subcarriers in a base station in a multi-carrier, multi-cell, wireless communication system comprised of a plurality of mobile stations and base stations in a plurality of cells, the base station associated with a cell in the plurality of cells, including a transmitter that is synchronized in time and frequency with transmitters in other base stations in the system, and configured for generating different types of subcarriers within a same frequency band that is divided into a plurality of subcarriers, the method comprising:

• generating common data subcarriers that carry data common to the plurality of cells to mobile stations in the plurality of cells;
• generating common pilot subcarriers that possess characteristics common to other common pilot subcarriers generated by the other base stations in the system, the common pilot subcarriers enabling a mobile station in the cell to determine composite channel coefficients and apply the composite channel coefficients to signals on the common data subcarriers received by the mobile station to compensate for composite channel effects and to recover common data carried by the common data subcarriers, wherein the composite channel corresponds to an aggregate of different channels from the plurality of base stations to the mobile station;
• generating cell-specific data subcarriers that carry data specific to the cell associated with the base station to individual mobile stations within the cell;
• and
• generating cell-specific pilot subcarriers that possess specific characteristics, in phase, amplitude, or frequency index, corresponding to the cell associated with the base station, the cell-specific pilot subcarriers enabling a mobile station in the cell to determine cell-specific channel coefficients and apply the cell-specific channel coefficients to signals on the cell-specific data subcarriers received by the mobile station to compensate for cell-specific channel effects and recover cell-specific data carried by the cell-specific data subcarriers, wherein the cell-specific channel corresponds to the channel from the base station in the cell to the mobile station;
• wherein:
• the common pilot subcarriers generated by the base station and common pilot subcarriers generated by the other base stations in the system are aligned in frequency subcarrier index, and at least some of the cell-specific pilot subcarriers generated by the base station are not aligned in frequency subcarrier index with cell-specific pilot subcarriers generated by the other base stations;
• and
• the common data subcarriers generated by the base station and common data subcarriers generated by the other base stations in the system are aligned in frequency subcarrier index, and at least some of the cell-specific data subcarriers generated by the base station are not aligned in frequency subcarrier index with cell-specific data subcarriers generated by the other base stations.

A method of receiving frequency subcarriers by a mobile station in a multi-carrier multi-cell wireless communication system comprised of a plurality of mobile stations and base stations in a plurality of cells, the mobile station associated with a serving base station in a serving cell and including a receiver configured to receive different types of subcarriers within a same frequency band that is divided into a plurality of subcarriers, the method comprising:

• receiving common data subcarriers that carry data common to the plurality of cells, the common data subcarriers transmitted by the serving base station being aligned in frequency subcarrier index with common data subcarriers transmitted by other base stations in the system;
• receiving common pilot subcarriers that possess characteristics common to the plurality of cells, the common pilot subcarriers transmitted by the serving base station being aligned in frequency subcarrier index with common pilot subcarriers transmitted by the other base stations in the system;
• receiving cell-specific data subcarriers that carry data specific to the serving cell,
• at least some of the cell-specific data subcarriers transmitted by the serving base station being not aligned in frequency subcarrier index with cell-specific data subcarriers transmitted by the other base stations in the system;
• and
• receiving cell-specific pilot subcarriers that possess specific characteristics, in phase, amplitude, or frequency subcarrier index, corresponding to the serving cell, at least some of the cell-specific pilot subcarriers transmitted by the serving base station being not aligned in frequency subcarrier index with cell-specific pilot subcarriers transmitted by the other base stations in the system;
• wherein:
• composite channel coefficients are determined based on received signals on
• the common pilot subcarriers and applied to received signals on the common data subcarriers to compensate for composite channel effects and to recover the common data carried on the common data subcarriers, wherein the composite channel corresponds to an aggregate of different
• channels from the plurality of base stations to the mobile station;
• and cell-specific channel coefficients are determined based on received signals on the cell-specific pilot subcarriers and applied to received signals on cell-specific data subcarriers to compensate for cell-specific channel effects and to recover cell-specific data carried on the cell-specific data subcarriers, wherein the cell-specific channel corresponds to the channel from the serving base station to the mobile station.

A base station in a multi-carrier, multi-cell, wireless communication system comprised of a plurality of mobile stations and base stations in a plurality of cells, the base station associated with a cell in the plurality of cells, including a transmitter that is synchronized in time and frequency with transmitters in other base stations in the system, and configured for transmitting common pilot subcarriers, common data subcarriers, cell-specific pilot subcarriers, and cell-specific data subcarriers within a same frequency band that is divided into a plurality of subcarriers,

• wherein:
• the common pilot subcarriers possess characteristics common to the plurality of cells, and the cell-specific pilot subcarriers possess specific characteristics, in phase, amplitude, or frequency index, corresponding to the cell;
• the common pilot subcarriers transmitted by the base station are aligned in frequency subcarrier index with common pilot subcarriers transmitted by the other base stations in the system, and at least some of the cell-specific pilot subcarriers transmitted by the base station are not aligned in frequency subcarrier index with cell-specific pilot subcarriers transmitted by the other base stations in the system;
• the common data subcarriers carry data common to the plurality of cells, and the cell-specific data subcarriers carry data specific to the cell;
• and the common data subcarriers transmitted by the base station are aligned in frequency subcarrier index with common data subcarriers transmitted by the other base stations in the system, and at least some of the cell-specific data subcarriers transmitted by the base station are not aligned in frequency subcarrier index with cell-specific data subcarriers transmitted by the other base stations in the system.

A mobile station in a multi-carrier, multi-cell, wireless

• communication system comprised of a plurality of mobile stations and base stations in a plurality of cells, the mobile station including a receiver configured for receiving, within a same frequency band that is divided into a plurality of subcarriers, cell-specific pilot subcarriers and cell-specific data subcarriers transmitted from a serving base station in a serving cell in which the mobile station is associated, and common pilot subcarriers and common data subcarriers transmitted from the serving base station and other base stations in the system, wherein:
• the common pilot subcarriers possess characteristics common to the plurality of cells, and the cell-specific pilot subcarriers possess specific characteristics, in phase, amplitude, or frequency index, corresponding to the serving cell;
• the common pilot subcarriers transmitted by the serving base station are aligned in frequency subcarrier index with common pilot subcarriers transmitted by other base stations in the system, and at least some of the cell-specific pilot subcarriers transmitted by the serving base station are not aligned in frequency subcarrier index with cell-specific pilot subcarriers transmitted by the other base stations in the system;
• the common data subcarriers carry data common to the plurality of cells, and the cell-specific data subcarriers carry data specific to the serving cell;
• and the common data subcarriers transmitted by the serving base station are aligned in frequency subcarrier index with common data subcarriers transmitted by the other base stations in the system, and at least some of the cell-specific data subcarriers transmitted by the serving base station are not aligned in frequency subcarrier index with cell-specific data subcarriers transmitted by the other base stations.