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US 7,352,688 B1Granted
High data rate wireless bridging
AssigneeCisco Technology, Inc.
InventorsEldad Perahia, Bretton Douglas, David Pignatelli
Life of this patent
Estimating the term…
Abstract
A specialized preamble is provided to facilitate matrix channel estimation of a MIMO channel. In a particular implementation, a channel training preamble provided by the IEEE 802.11a standard is modified to facilitate MIMO channel estimation.
Claims12
In a wireless communication system, a method for transmitting a signal, said method comprising:
- transmitting a first OFDM signal via a first antenna element representing a horizontal polarization of an antenna;
- transmitting a second OFDM signal via a second antenna element representing a vertical polarization of said antenna;
- transmitting channel training information in said first OFDM signal while inhibiting transmission of said second OFDM signal during a first channel training period;
- and
- transmitting channel training information in said second OFDM signal while inhibiting transmission of said first OFDM signal in a second channel training period;
- wherein said channel training information is configured for use by a receiver in determining a MIMO channel response.
3 more elements
In a wireless communication system, a method for transmitting a signal, said method comprising:
- transmitting a first OFDM signal via a first antenna element representing a horizontal polarization of an antenna;
- transmitting a second OFDM signal via a second antenna element representing a vertical polarization of said antenna;
- and
- during a channel training period, transmitting channel training information simultaneously in a first set of subcarriers of said first OFDM signal and in a second set of subcarriers of the second OFDM signal, said first set of subcarriers and said second set of subcarriers being non-overlapping;
- wherein said channel training information is configured for use by a receiver in determining a MIMO channel response.
2 more elements
In a wireless communication system, apparatus for transmitting a signal, said apparatus comprising:
- a first transmitter block that transmits a first OFDM signal via a first antenna element representing a horizontal polarization of an antenna;
- a second transmitter block that transmits a second OFDM signal via a second antenna element representing a vertical polarization of said antenna;
- a first channel training information insertion block that inserts channel training information in said first OFDM signal while transmission of said second OFDM signal is inhibited;
- and
- a second channel training information insertion block that inserts channel training information in said second OFDM signal while transmission of said first OFDM signal is inhibited;
- wherein said channel training information is configured for use by a receiver in determining a MIMO channel response.
3 more elements
In a wireless communication system, apparatus for transmitting a signal, said apparatus comprising:
- a first transmitter block that transmits a first OFDM signal via a first antenna element representing a horizontal polarization of an antenna;
- a second transmitter block that transmits a second OFDM signal via a second antenna element representing a vertical polarization of said antenna;
- a channel training information insertion system that during a channel training period, transmits channel training information simultaneously in a first set of subcarriers of said first OFDM signal and in a second set of subcarriers of the second OFDM signal, said first set of subcarriers and said second set of subcarriers being non-overlapping;
- wherein said channel training information is configured for use by a receiver in determining a MIMO channel response.
1 more element
In a wireless communication system, apparatus for transmitting a signal, said apparatus comprising:
- means for transmitting a first OFDM signal via a first antenna element representing a horizontal polarization of an antenna;
- means for transmitting a second OFDM signal via a second antenna element representing a vertical polarization of said antenna;
- means for transmitting channel training information in said first OFDM signal while inhibiting transmission of said second OFDM signal;
- and
- means for transmitting channel training information in said second OFDM signal while inhibiting transmission of said first OFDM signal;
- wherein said channel training information is configured for use by a receiver in determining a MIMO channel response.
3 more elements
In a wireless communication system, apparatus for transmitting a signal, said apparatus comprising:
- means for transmitting a first OFDM signal via a first antenna element representing a horizontal polarization of an antenna;
- means for transmitting a second OFDM signal via a second antenna element representing a vertical polarization of said antenna;
- and
- means for, during a channel training period, transmitting channel training information simultaneously in a first set of subcarriers of said first OFDM signal and in a second set of subcarriers of the second OFDM signal, said first set of subcarriers and said second set of subcarriers being non-overlapping
- wherein said channel training information is configured for use by a receiver in determining a MIMO channel response.
2 more elements
Dependencies are inferred from the claim text.