SOFT HANDOFF IN OFDMA SYSTEM
First Claim
1. A base station in an orthogonal frequency division multiplexing access (OFDMA) system comprising:
- a) subchannel definition logic adapted to provide a subchannel definition to a first plurality of subcarriers;
b) dividing and multiplexing encoding logic adapted to provide dividing-multiplexing coding for a plurality of orthogonal frequency division multiplexing (OFDM) symbols, said OFDM symbols comprising said first plurality of subcarriers;
c) Inverse Fourier Transform (IFT) logic adapted to provide an IFT on each of said first plurality of subcarriers to generate said plurality of OFDM symbols, said first plurality of subcarriers being defined in a soft handoff zone comprising a first dimension of subchannels, said first dimension of subchannels comprising said first plurality of subcarriers; and
a second dimension of a divided and multiplexed plurality of OFDM symbols;
said first plurality of subcarriers in said soft handoff zone having the subchannel definition; and
d) transmit circuitry transmitting said first plurality of subcarriers for reception by a subscriber station.
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Accused Products
Abstract
Soft handoff in an OFDMA system is disclosed. If the pilot signal strength for a base station exceeds the defined threshold, the base station is added to an active set list. Subcarriers in a plurality of orthogonal frequency division multiplexing (OFDM) symbols are divided and allocated into subchannels. The OFDM symbols are divided and multiplexed. A soft handoff zone with a first dimension of the subchannels and a second dimension of the divided and multiplexed OFDM symbols is defined. The soft handoff zone has subcarriers with a subchannel definition, for example, an identical permutation.
14 Citations
22 Claims
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1. A base station in an orthogonal frequency division multiplexing access (OFDMA) system comprising:
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a) subchannel definition logic adapted to provide a subchannel definition to a first plurality of subcarriers; b) dividing and multiplexing encoding logic adapted to provide dividing-multiplexing coding for a plurality of orthogonal frequency division multiplexing (OFDM) symbols, said OFDM symbols comprising said first plurality of subcarriers; c) Inverse Fourier Transform (IFT) logic adapted to provide an IFT on each of said first plurality of subcarriers to generate said plurality of OFDM symbols, said first plurality of subcarriers being defined in a soft handoff zone comprising a first dimension of subchannels, said first dimension of subchannels comprising said first plurality of subcarriers; and
a second dimension of a divided and multiplexed plurality of OFDM symbols;
said first plurality of subcarriers in said soft handoff zone having the subchannel definition; andd) transmit circuitry transmitting said first plurality of subcarriers for reception by a subscriber station. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of operating a base station in an orthogonal frequency division multiplexing access (OFDMA) system, the method comprising:
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a) providing a subchannel definition to a first plurality of subcarriers; b) providing dividing-multiplexing coding for a plurality of orthogonal frequency division multiplexing (OFDM) symbols, said OFDM symbols comprising said first plurality of subcarriers; c) providing an Inverse Fourier Transform (IFT) on each of said first plurality of subcarriers to generate said plurality of OFDM symbols, said first plurality of subcarriers being defined in a soft handoff zone comprising a first dimension of subchannels, said first dimension of subchannels comprising said first plurality of subcarriers, and a second dimension of divided and multiplexed plurality of OFDM symbols, said first plurality of subcarriers in said soft handoff zone having the subchannel definition; and d) transmitting said first plurality of subcarriers for reception by a subscriber station. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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Specification