Training symbol format for adaptively power loaded MIMO
First Claim
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1. A method for use in performing channel training in a MIMO based multicarrier system, comprising:
- for a first training time slot within a data frame, dividing tones of a first OFDM training symbol among K spatial channels, wherein each of said tones of said first OFDM training symbol is transmitted in only one of said K spatial channels during said first training time slot; and
for a second training time slot within said data frame, dividing tones of a second OFDM training symbol among said K spatial channels, wherein each of said tones of said second OFDM training symbol is transmitted in only one of said K spatial channels during said second training time slot and tones from said first training time slot are not repeated within the same spatial channel in said second training time slot;
wherein tones transmitted within a first spatial channel of said K spatial channels during said first and second training time slots are transmitted at a power level that is proportional by a predetermined factor to a power level used to transmit user data in said first spatial channel within said data frame and tones transmitted within a second spatial channel of said K spatial channels during said first and second training time slots are transmitted at a power level that is proportional by said predetermined factor to a power level used to transmit user data in said second spatial channel within said data frame, wherein said power levels used to transmit said user data within said first and second spatial channels are set using adaptive power loading techniques.
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Abstract
Training symbol formats are provided for use in a MIMO based wireless communication system that uses adaptive power loading. In at least one embodiment, a training symbol format is used that is capable of enhancing training symbol signal to noise ratio (SNR).
29 Citations
35 Claims
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1. A method for use in performing channel training in a MIMO based multicarrier system, comprising:
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for a first training time slot within a data frame, dividing tones of a first OFDM training symbol among K spatial channels, wherein each of said tones of said first OFDM training symbol is transmitted in only one of said K spatial channels during said first training time slot; and for a second training time slot within said data frame, dividing tones of a second OFDM training symbol among said K spatial channels, wherein each of said tones of said second OFDM training symbol is transmitted in only one of said K spatial channels during said second training time slot and tones from said first training time slot are not repeated within the same spatial channel in said second training time slot; wherein tones transmitted within a first spatial channel of said K spatial channels during said first and second training time slots are transmitted at a power level that is proportional by a predetermined factor to a power level used to transmit user data in said first spatial channel within said data frame and tones transmitted within a second spatial channel of said K spatial channels during said first and second training time slots are transmitted at a power level that is proportional by said predetermined factor to a power level used to transmit user data in said second spatial channel within said data frame, wherein said power levels used to transmit said user data within said first and second spatial channels are set using adaptive power loading techniques. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. An apparatus comprising:
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a wireless transceiver to generate radio frequency transmit signals for delivery to multiple transmit antennas; and a controller, coupled to said wireless transceiver, to cause a data frame to be transmitted from said apparatus into a MIMO channel, said data frame having a per stream training portion and a user data portion, wherein said per stream training portion includes at least a first training time slot and a second training time slot, said first training time slot to have training tones of a first OFDM training symbol divided among a plurality of spatial channels in said MIMO channel and said second training time slot to have training tones of a second OFDM training symbol divided among said plurality of spatial channels in said MIMO channel; wherein said plurality of spatial channels includes at least a first spatial channel and a second spatial channel; and wherein said training tones transmitted in said first spatial channel are transmitted at a power level that is proportional by a predetermined factor to a power level at which user data in said data frame is transmitted within said first spatial channel and said training tones transmitted in said second spatial channel are transmitted at a power level that is proportional by said predetermined factor to a power level at which user data in said data frame is transmitted within said second spatial channel. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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21. A system comprising:
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a plurality of dipole antennas; a wireless transceiver to generate radio frequency transmit signals for delivery to said plurality of dipole antennas; and a controller, coupled to said wireless transceiver, to cause a data frame to be transmitted from said apparatus into a MIMO channel, said data frame having a per stream training portion and a user data portion, wherein said per stream training portion includes at least a first training time slot and a second training time slot, said first training time slot to have training tones of a first OFDM training symbol divided among a plurality of spatial channels in said MIMO channel and said second training time slot to have training tones of a second OFDM training symbol divided among said plurality of spatial channels in said MIMO channel; wherein said plurality of spatial channels includes at least a first spatial channel and a second spatial channel; and wherein said training tones transmitted in said first spatial channel are transmitted at a power level that is proportional by a predetermined factor to a power level at which user data in said data frame is transmitted within said first spatial channel and said training tones transmitted in said second spatial channel are transmitted at a power level that is proportional by a predetermined factor to a power level at which user data in said data frame is transmitted within said second spatial channel. - View Dependent Claims (22, 23, 24)
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25. An article comprising a computer readable storage medium having instructions stored thereon that, when executed by a computing platform, operate to:
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for a first training time slot within a data frame, divide tones of a first OFDM training symbol among K spatial channels for transmission, wherein each of said tones of said OFDM training symbol are transmitted in only one of said K spatial channels during said first training time slot; and for a second training time slot within said data frame, divide tones of a second OFDM training symbol among said K spatial channels, wherein each of said tones of said second OFDM training symbol are transmitted in only one of said K spatial channels during said second training time slot and tones from said first training time slot are not repeated within the same spatial channel in said second training time slot; wherein tones transmitted within said K spatial channels during said first and second training time slots are transmitted at power levels that are proportional to power levels used to transmit user data in said K spatial channels within said data frame, wherein said power levels used to transmit said user data within said K spatial channels are set using adaptive power loading techniques. - View Dependent Claims (26, 27, 28)
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29. A method for use in performing channel training in a MIMO based multicarrier system, comprising:
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for a first training time slot within a data frame, interleaving tones of a first OFDM training symbol across K spatial channels, wherein each of said tones of said first OFDM training symbol is transmitted in only one of said K spatial channels during said first training time slot; and for a second training time slot within said data frame, interleaving tones of a second OFDM training symbol among said K spatial channels, wherein each of said tones of said second OFDM training symbol is transmitted in only one of said K spatial channels during said second training time slot and tones from said first training time slot are not repeated within the same spatial channel in said second training time slot, wherein a transmit power level of training tones transmitted within a first spatial channel of said K spatial channels is proportional to a transmit power level used to transmit user data within said first spatial channel during said data frame and a transmit power level of training tones transmitted within a second spatial channel of said K spatial channels is proportional to a transmit power level used to transmit user data within said second spatial channel during said data frame. - View Dependent Claims (30, 31)
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32. A method for use in performing channel training in a MIMO based multicarrier system, comprising:
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transmitting a first OFDM training symbol into a MIMO channel during a first training time slot of a data frame, said MIMO channel having at least a first spatial channel and a second spatial channel; transmitting a second OFDM training symbol into said MIMO channel during a second training time slot of said data frame; transmitting adaptive power loading information within said data frame, said adaptive power loading information including an indication of the power loading ratio between said first and second spatial channels; transmitting user data into said first spatial channel and said second spatial channel during a user data portion of said data frame; wherein some training tones of said first and second OFDM training symbols are transmitted within a first spatial channel of said MIMO channel and some training tones of said first and second OFDM training symbols are transmitted within a second spatial channel of said MIMO channel, wherein training tones transmitted within said first and second spatial channels are transmitted at the same transmit power level. - View Dependent Claims (33, 34, 35)
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Specification