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US 7,352,819 B2Granted
Multiantenna communications apparatus, methods, and system
AssigneeIntel Corporation
InventorsSondur Lakshmipathi, Atanu Guchhait, Ashim Biswas
Life of this patent
Estimating the term…
Abstract
A transmitter may transmit using OFDM-MIMO or OFDM-SDMA depending on channel characteristics.
Claims16
A method comprising:
- estimating a multipath environment for each of a plurality of orthogonal frequency division multiplexing (OFDM) subchannels between a transmitter and a receiver;
- when the multipath environment includes multiple uncorrelated paths for each of the plurality of OFDM subchannels, preparing the transmitter to transmit using an OFDM multiple-input-multiple-output (MIMO) format by pre-filtering using separate channel estimation data for each of the OFDM subchannels;
- when the multipath environment includes multiple uncorrelated paths for less than all of the plurality of OFDM subchannels, preparing the transmitter to transmit using an OFDM-MIMO format by pre-filtering all OFDM subchannel data using channel estimation data from only one of the plurality of OFDM subchannels;
- when the multipath environment includes multiple correlated paths for each of the plurality of OFDM subchannels, preparing the transmitter to transmit using an OFDM spatial division multiple access (SDMA) format;
- and
- transmitting data from the transmitter.
3 more elements
A method comprising:
- receiving channel state information corresponding to a plurality of orthogonal frequency division multiplexing (OFDM) subchannels;
- transmitting using an OFDM multiple input multiple output (MIMO) format wherein each OFDM subchannel is pre-filtered using channel state information corresponding to that OFDM subchannel if the channel state information indicates the existence of a rich multipath scattering environment for all OFDM subchannels;
- transmitting using an OFDM-MIMO format wherein all OFDM subchannels are pre-filtered using channel state information corresponding to a single OFDM subchannel if the channel state information indicates the existence of a rich multipath scattering environment for less than all OFDM subchannels;
- and
- otherwise transmitting using an OFDM spatial division multiple access (SDMA) format.
2 more elements
An apparatus having a computer-readable medium with instructions stored thereon that when accessed, result in a computer performing:
- configuring a transmitter to transmit using an orthogonal frequency division multiplexing multiple input multiple output (OFDM-MIMO) format by pre-filtering using separate channel estimation data for each of a plurality of OFDM subchannels when channel state information indicates the existence of a rich multipath scattering environment in each of the plurality of OFDM subchannels;
- configuring the transmitter to transmit using an OFDM-MIMO format by pre-filtering all of the plurality of OFDM subchannels using channel estimation data from only one of the plurality of OFDM subchannels when channel state information indicates the existence of a rich multipath scattering environment in less than all of the plurality of OFDM subchannels;
- configuring the transmitter to transmit using an OFDM spatial division multiple access (SDMA) format when channel state information indicates the existence a strong line of sight component;
- and
- transmitting from the transmitter.
2 more elements
Dependencies are inferred from the claim text.