Feedback of channel information in a closed loop beamforming wireless communication system
View Patent ↗A method for feeding back transmitter beamforming information from a receiving wireless communication device to a transmitting wireless communication device includes a receiving wireless communication device receiving a preamble sequence from the transmitting wireless device. The receiving wireless device estimates a channel response based upon the preamble sequence and then determines an estimated transmitter beamforming unitary matrix based upon the channel response and a receiver beamforming unitary matrix. The receiving wireless device then decomposes the estimated transmitter beamforming unitary matrix to produce the transmitter beamforming information and then wirelessly sends the transmitter beamforming information to the transmitting wireless device.
1. A radio transceiver, comprising:
a radio front end for communicating wirelessly with a transmitting device at a high throughput (HT) data rate, in which the radio front end receives a signal transmitted from the transmitting device, the wireless communicating comprising at least one of the transmitting device transmitting the signal over multiple antennas or the radio front end receiving the signal over multiple antennas; and
a baseband processing logic to process the signal received by the radio front end to estimate transmitter beamforming parameters and to generate feedback information to the transmitting device regarding capabilities of the radio transceiver, the feedback information to be provided in an expansion of an established frame required of a communication protocol signal used for feedback transmission to the transmitting device, wherein the feedback information is appended as an extended field to a selected field of the frame and the feedback information includes a first appended bit to indicate that the radio transceiver is capable of receiving and transmitting beamformed signals, a second appended bit to indicate that the radio transceiver is capable of generating and transmitting channel estimates in a matrix form, and a third appended bit to indicate that the radio transceiver is capable of generating channel estimates and transmitting reduced format channel estimates, in which the feedback information is transmitted back to the transmitting device for the transmitting device to alter subsequent forward link transmissions to the radio transceiver based on capabilities of the radio transceiver.
2. The radio transceiver of claim 1 , wherein the frame includes a frame identification field, a HT capabilities field, a medium access layer HT parameters field, a supported modulation and coding set field, and a frame length field, in which the frame length field indicates additional length allocated to the frame to include the feedback information being sent in the feedback transmission.
3. The radio transceiver of claim 2 , wherein the frame containing the feedback information further including a vendor field for specifying a specific vendor or vendor parameter.
4. The radio transceiver of claim 2 , wherein the frame containing the feedback information further including a type field for specifying whether an HT element is present.
5. The radio transceiver of claim 2 , wherein the selected field is the HT capabilities field.
6. The radio transceiver of claim 5 , wherein the communication protocol designates the signal to utilize 802.11(n) communication protocol.
7. The radio transceiver of claim 5 , wherein the extended field further including a sounding indicator field that is operable to signal a sounding frame.
8. The radio transceiver of claim 7 , wherein the sounding indicator field is operable to signal sounding by specifying at least one of a frame not being a sounding frame, a frame having sounding with one or more transmit antenna, a frame having sounding with two or more transmit antennas, or a frame having sounding with three or more transmit antennas.
9. The radio transceiver of claim 7 , wherein the extended field further including an indication that the radio transceiver is staggered sounding capable.
10. The radio transceiver of claim 7 , wherein the extended field further including an indication that the radio transceiver is non-staggered sounding capable.
11. The radio transceiver of claim 2 , wherein the feedback information to include a fourth appended bit to indicate that the radio transceiver is capable of calibrating beamforming based upon a received channel estimate in full or reduced matrix format.
12. A radio transceiver, comprising:
a radio front end for communicating wirelessly with a transmitting device, in which the radio front end receives a signal transmitted from the transmitting device, the wireless communicating comprising at least one of the transmitting device transmitting the signal over multiple antennas or the radio front end receiving the signal over multiple antenna; and
a baseband processing logic to process the signal received by the radio front end to estimate transmitter beamforming parameters and to generate feedback information to the transmitting device regarding capabilities of the radio transceiver, the feedback information to be provided in an expansion of an established frame required of a 802.11(n) communication protocol signal used for feedback transmission to the transmitting device, wherein the feedback information is appended as an extended field to a high throughput (HT) capabilities field of the frame and the feedback information includes a first bit to indicate that the radio transceiver is capable of receiving and transmitting beamformed signals, a second bit to indicate that the radio transceiver is capable of generating and transmitting channel estimates in a matrix form, and a third bit to indicate that the radio transceiver is capable of generating channel estimates and transmitting reduced format channel estimates, in which the feedback information is transmitted back to the transmitting device for the transmitting device to alter subsequent forward link transmissions to the radio transceiver based on capabilities of the radio transceiver.
13. The radio transceiver of claim 12 , wherein the feedback information to include a fourth bit to indicate that the radio transceiver is capable of calibrating beamforming based upon a received channel estimate in full or reduced matrix format.
14. The radio transceiver of claim 12 , wherein the frame includes a frame identification field, the HT capabilities field, a medium access layer HT parameters field, a supported modulation and coding set field, and a frame length field, in which the frame length field indicates additional length allocated to the frame to include the feedback information being sent in the feedback transmission.
15. The radio transceiver of claim 12 , wherein the frame containing the feedback information further including a vendor field for specifying a specific vendor or vendor parameter.
16. The radio transceiver of claim 12 , wherein the frame containing the feedback information further including a type field for specifying whether an HT element is present.
17. The radio transceiver of claim 12 , wherein the extended field further including a sounding indicator field that is operable to signal a sounding frame.
18. The radio transceiver of claim 17 , wherein the sounding indicator field is operable to signal sounding by specifying at least one of a frame not being a sounding frame, a frame having sounding with one or more transmit antenna, a frame having sounding with two or more transmit antennas, or a frame having sounding with three or more transmit antennas.
19. The radio transceiver of claim 17 , wherein the extended field further including an indication that the radio transceiver is staggered sounding capable.
20. The radio transceiver of claim 17 , wherein the extended field further including an indication that the radio transceiver is non-staggered sounding capable.