Differential randomization of cell-specific and common pilot subcarriers in multi-carrier, multi-cell wireless communication networks
First Claim
1. A mobile station in an orthogonal frequency division multiplexing (OFDM) wireless communication system comprised of a plurality of base stations in a plurality of cells, the mobile station comprising:
- a receiver configured to receive a set of cell-specific pilot subcarriers from a first base station in a first cell in which the mobile station is operating, wherein the set of cell-specific pilot subcarriers were generated by a first randomization process specific to the first cell;
the receiver is further configured to receive a set of common pilot subcarriers from the first base station in the first cell and from a second base station in a second cell, wherein;
the first cell and the second cell are in a group with a common group identifier; and
the common pilot subcarriers from the first base station and the common pilot subcarriers from the second base station were generated by a second randomization process common to both the first cell and the second cell, the second randomization process randomizing the common pilot subcarriers differently than in cells having a different common group identifier; and
the receiver is further configured to apply the received set of cell-specific pilot subcarriers to determine cell-specific channel coefficients for a cell-specific channel, the cell-specific channel corresponding to a channel from the first base station to the mobile station.
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Accused Products
Abstract
A multi-carrier cellular wireless network (400) employs base stations (404) that transmit two different groups of pilot subcarriers: (1) cell-specific pilot subcarriers, which are used by a receiver to extract information unique to each individual cell (402), and (2) common pilots subcarriers, which are designed to possess a set of characteristics common to all the base stations (404) of the system. The design criteria and transmission formats of the cell-specific and common pilot subcarriers are specified to enable a receiver to perform different system functions. The methods and processes can be extended to other systems, such as those with multiple antennas in an individual sector and those where some subcarriers bear common network/system information.
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Citations
14 Claims
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1. A mobile station in an orthogonal frequency division multiplexing (OFDM) wireless communication system comprised of a plurality of base stations in a plurality of cells, the mobile station comprising:
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a receiver configured to receive a set of cell-specific pilot subcarriers from a first base station in a first cell in which the mobile station is operating, wherein the set of cell-specific pilot subcarriers were generated by a first randomization process specific to the first cell; the receiver is further configured to receive a set of common pilot subcarriers from the first base station in the first cell and from a second base station in a second cell, wherein; the first cell and the second cell are in a group with a common group identifier; and the common pilot subcarriers from the first base station and the common pilot subcarriers from the second base station were generated by a second randomization process common to both the first cell and the second cell, the second randomization process randomizing the common pilot subcarriers differently than in cells having a different common group identifier; and the receiver is further configured to apply the received set of cell-specific pilot subcarriers to determine cell-specific channel coefficients for a cell-specific channel, the cell-specific channel corresponding to a channel from the first base station to the mobile station. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for a mobile station in an orthogonal frequency division multiplexing (OFDM) wireless communication system comprised of a plurality of base stations in a plurality of cells, the method comprising:
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receiving a set of cell-specific pilot subcarriers from a first base station in a first cell in which the mobile station is operating, wherein the set of cell-specific pilot subcarriers were generated by a first randomization process specific to the first cell; receiving a set of common pilot subcarriers from the first base station in the first cell and from a second base station in a second cell, wherein; the first cell and the second cell are in a group with a common group identifier; and the common pilot subcarriers from the first base station and the common pilot subcarriers from the second base station were generated by a second randomization process common to both the first cell and the second cell, the second randomization process randomizing the common pilot subcarriers differently than in cells having a different common group identifier; and applying the received set of cell-specific pilot subcarriers to determine cell-specific channel coefficients for a cell-specific channel, the cell-specific channel corresponding to a channel from the first base station to the mobile station. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification