Systems and methods for forward link closed loop beamforming
First Claim
1. A method of communicating information between a wireless terminal and a transmitter including an antenna having a plurality of antenna feed elements, comprising:
- generating channel estimates for a plurality of channels at the wireless terminal from the plurality of antenna feed elements;
obtaining channel phase information from the channel estimates;
quantizing the channel phase information using a 2-bit quantization for each channel to obtain quantized channel phase values; and
transmitting the quantized channel phase values to the transmitter.
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Accused Products
Abstract
Methods of forming a beam to a wireless terminal from a transmitter including an antenna having a plurality of antenna feed elements include generating channel estimates at the wireless terminal, obtaining channel phase information from the channel estimates, quantizing the channel phase information to obtain quantized channel phase values, and transmitting the quantized channel phase values to the transmitter. The methods may further include receiving the quantized channel phase values at the transmitter, obtaining channel gain estimates, constructing channel estimates using the quantized channel phase values and the channel gain estimates, and determining transmit beamforming weights in response to the channel estimates. Related transmitters, wireless terminals, and communications systems are also disclosed.
154 Citations
56 Claims
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1. A method of communicating information between a wireless terminal and a transmitter including an antenna having a plurality of antenna feed elements, comprising:
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generating channel estimates for a plurality of channels at the wireless terminal from the plurality of antenna feed elements; obtaining channel phase information from the channel estimates; quantizing the channel phase information using a 2-bit quantization for each channel to obtain quantized channel phase values; and transmitting the quantized channel phase values to the transmitter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A transmitter for use in a wireless communications system, comprising:
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a plurality of antenna feed elements; a phase bits detector configured to receive quantized channel phase values; a phase vector constructor configured to generate a vector of channel phase estimates for a plurality of channels from the plurality of antenna feed elements to a wireless terminal in response to the quantized channel phase values; a gain vector constructor configured to generate a vector of channel gain estimates for the plurality of channels; a vector channel constructor configured to generate a vector of channel estimates for the plurality of channels in response to the vector of channel phase estimates and the vector of channel gain estimates; and an adaptive beamformer configured to generate a vector of transmit beamforming weights in response to the vector of channel estimates. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25)
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26. A wireless terminal for use in a communications system, comprising:
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a vector channel estimator configured to generate channel estimates for a plurality of channels at the wireless terminal from a plurality of antenna feed elements at a remote transmitter; a phase vector calculator configured to obtain channel phase information from the channel estimates; and a phase quantizer configured to quantize the channel phase information using a 2-bit quantization for each channel to obtain quantized channel phase values. - View Dependent Claims (27, 28, 29, 30, 31, 32)
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33. A communications system, comprising:
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(a) a wireless terminal comprising; a vector channel estimator configured to generate channel estimates for a plurality of channels at the wireless terminal from a plurality of antenna feed elements; a phase vector calculator configured to obtain channel phase information from the channel estimates; a phase quantizer configured to quantize the channel phase information to obtain quantized channel phase values; and a transceiver configured to transmit the quantized channel phase values; and (b) a transmitter, comprising; the plurality of antenna feed elements; a phase bits detector configured to receive the quantized channel phase values from the wireless terminal; a phase vector constructor configured to generate a vector of channel phase estimates for the plurality of channels in response to the quantized channel phase values, wherein the plurality of channels comprise channels from the plurality of antenna feed elements to the wireless terminal; a gain vector constructor configured to generate a vector of channel gain estimates for the plurality of channels; a vector channel constructor configured to generate a vector of channel estimates for the plurality of channels in response to the vector of channel phase estimates and the vector of channel gain estimates; and an adaptive beamformer configured to generate a vector of transmit beamforming weights in response to the vector of channel estimates. - View Dependent Claims (34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47)
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48. A method of forming a beam to a wireless terminal from a transmitter including an antenna having a plurality of antenna feed elements, comprising:
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receiving quantized channel phase values from the wireless terminal; obtaining channel gain estimates for each of the plurality of antenna feed elements; constructing channel estimates for a plurality of channels using the quantized channel phase values and the channel gain estimates; and determining transmit beamforming weights in response to the channel estimates. - View Dependent Claims (49, 50, 51, 52, 53, 54, 55, 56)
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Specification