Cooperative wireless networks
First Claim
1. A cooperative multi-user multiple input, multiple output (MIMO) system, comprising:
- at least one MIMO processor configured to pre-code a plurality of data streams to generate a plurality of subspace-coded data streams, each subspace-coded data stream comprising a linear combination constructed from a sum of a plurality of terms multiplied by coefficients, the plurality of terms comprising at least a subset plurality of the plurality of data streams, and the coefficients comprising MIMO subspace code values based on channel state information corresponding to channels between a plurality of spatially distributed transceiver stations and a plurality of wireless client devices;
a network interface communicatively coupled to the plurality of spatially distributed transceiver stations via a network; and
a network controller configured to send the subspace-coded data streams to the plurality of spatially distributed transceiver stations via the network, and coordinate the plurality of spatially distributed transceiver stations to simultaneously transmit the subspace-coded data streams over wireless links to each of the plurality of wireless client devices, the MIMO subspace code values providing for transmissions comprising a plurality of simultaneous non-interfering subspace channels within a common frequency, wherein first portions of transmissions received at a first wireless client device coherently combine to produce at least a first set of the plurality of data streams, and wherein at least second portions of the transmissions received at the first wireless client device combine to cancel at least a second set of the plurality of data streams intended for at least a second wireless client device.
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Accused Products
Abstract
A cooperative multi-user multiple input, multiple output (MIMO) system coordinates spatially distributed transceiver stations for communicating with wireless client devices. The system comprises a network interface communicatively coupled to the transceiver stations via a backhaul network, which may comprise a wireless local area network. A MIMO processor pre-codes NR original data streams to generate NT subspace-coded data streams, wherein each subspace-coded data stream comprises a linear combination of at least some of the original data streams. NT may denote a number of transmitting antennas, and NR may denote a number of receiving antennas. A network controller conveys the subspace-coded data streams to the transceiver stations via the backhaul network and coordinates the simultaneous transmission of the subspace-coded data streams over wireless links to the wireless client devices. The pre-coding causes the transmissions to coherently combine at a first wireless client device to produce at least a first data stream while suppressing inter-user interference from at least a second data stream intended for at least a second wireless client device. The client devices and/or the transceiver stations may be selected based on channel state information and/or measured channel quality.
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Citations
20 Claims
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1. A cooperative multi-user multiple input, multiple output (MIMO) system, comprising:
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at least one MIMO processor configured to pre-code a plurality of data streams to generate a plurality of subspace-coded data streams, each subspace-coded data stream comprising a linear combination constructed from a sum of a plurality of terms multiplied by coefficients, the plurality of terms comprising at least a subset plurality of the plurality of data streams, and the coefficients comprising MIMO subspace code values based on channel state information corresponding to channels between a plurality of spatially distributed transceiver stations and a plurality of wireless client devices; a network interface communicatively coupled to the plurality of spatially distributed transceiver stations via a network; and a network controller configured to send the subspace-coded data streams to the plurality of spatially distributed transceiver stations via the network, and coordinate the plurality of spatially distributed transceiver stations to simultaneously transmit the subspace-coded data streams over wireless links to each of the plurality of wireless client devices, the MIMO subspace code values providing for transmissions comprising a plurality of simultaneous non-interfering subspace channels within a common frequency, wherein first portions of transmissions received at a first wireless client device coherently combine to produce at least a first set of the plurality of data streams, and wherein at least second portions of the transmissions received at the first wireless client device combine to cancel at least a second set of the plurality of data streams intended for at least a second wireless client device. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method comprising:
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generating channel estimates for wireless channels between a plurality of wireless client devices and a plurality of spatially distributed transceiver stations for producing channel state information; employing at least one of link quality and the channel state information for selecting the plurality of wireless client devices to be served by the plurality of spatially distributed transceiver stations, and selecting, for at least one client device of the plurality of wireless client devices, a subset plurality of the plurality of spatially distributed transceiver stations to serve the at least one client device; generating cooperative multiple input, multiple output (MIMO) subspace weights from the channel state information; generating pre-coded data comprising a plurality of linear combinations, each linear combination comprising a sum of a plurality of terms multiplied by coefficients, wherein the terms comprise data values and the coefficients comprise the MIMO subspace weights; and coordinating transmissions of the pre-coded data from at least the subset plurality of the plurality of spatially distributed transceiver stations to produce a plurality of non-interfering subspace channels in a common frequency, wherein first signal portions in transmissions received by a first wireless client device coherently combine to produce at least a first set of data streams, and second signal portions in the transmissions received by the first wireless client device combine to cancel at least a second set of data streams intended for at least a second wireless client device. - View Dependent Claims (9, 10, 11, 12, 13)
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14. A non-transitory computer readable storage medium having computer readable code thereon, the medium comprising instructions for:
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determining channel characterization data for channels between a plurality of spatially distributed transceiver stations and a plurality of wireless client devices to generate channel state information; selecting a subset plurality of the wireless client devices to share a common frequency based on at least one of the channel state information and measured link quality; computing a plurality of cooperative multiple input, multiple output (MIMO) subspace weights based on the channel characterization data; pre-coding data using the MIMO subspace weights to generate pre-coded data signals, each of the pre-coded data signals comprising a linear combination constructed from a sum of a plurality of terms multiplied by coefficients, the plurality of terms comprising the data, and the coefficients comprising MIMO subspace weights that provide a plurality of simultaneous non-interfering subspace channels within the common frequency when the pre-coded data signals are transmitted by the plurality of spatially distributed transceiver stations to the subset plurality of wireless client devices; and providing for transmitting the pre-coded data signals from each of the spatially distributed transceiver stations to each of the subset plurality of wireless client devices, wherein at least first portions of transmissions received by a first wireless client device from the plurality of spatially distributed transceiver stations coherently combine to produce at least a first set of data streams, and wherein at least second portions of the transmissions received by the first wireless client device combine to cancel at least a second set of data streams intended for at least one other wireless client device of the subset plurality. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification