Rate adaptation using semi-open loop technique
View Patent ↗In a semi-open loop rate adaptation scheme for a multiple-input multiple-output (MIMO) system, a transmitter can advantageously use one or more quality metrics of an uplink as well as knowledge of device characteristics of both ends to perform fast and accurate rate adaptation.
1. A method for adapting a rate in a multiple-input multiple-output (MIMO) system, comprising:
receiving, by a first node, from a second node, transmitter and/or receiver characteristics of the second node, the transmitter and/or receiver characteristics of the second node comprising at least one member selected from the group consisting of: a transmitter power per data rate table of the second node, a transmitter error vector magnitude (EVM) per transmitter power table of the second node, and a receiver sensitivity per data rate table of the second node including a first post-detection signal-to-noise ratio (SNR) per rate for a first packet error rate (PER);
transmitting, by the first node, to the second node, transmitter and/or receiver characteristics of the first node, the transmitter and/or receiver characteristics of the first node comprising at least one member selected from the group consisting of: a transmitter power per data rate table of the first node, a transmitter EVM per transmitter power table of the first node, and a receiver sensitivity per data rate table of the first node including a second post-detection SNR per rate for a second PER; and
adapting, by the first node, a data rate from the first node to the second node based at least in part on the transmitter and/or receiver characteristics of the first node and the transmitter and/or receiver characteristics of the second node.
2. The method of claim 1 , further comprising:
after transmitting transmitter and/or receiver characteristics of the first node to the second node, receiving, by the first node, information from the second node at an adapted data rate from the second node to the first node, wherein the adapted data rate from the second node to the first node is based at least in part on the transmitter and/or receiver characteristics of the first node and the transmitter and/or receiver characteristics of second node.
3. The method of claim 1 , further comprising:
adjusting the transmitter power per data rate table of the first node based at least in part on a received signal strength indicator (RSSI);
wherein transmitting the transmitter and/or receiver characteristics of the first node comprises transmitting the transmitter power per data rate table of the first node to the second node upon adjusting the transmitter power per data rate table of the first node.
4. The method of claim 1 , wherein transmitting the transmitter and/or receiver characteristics of the first node comprises transmitting the transmitter power per data rate table of the first node to the second node during an initial link setup between the first node and the second node.
5. The method of claim 3 , wherein adjusting the transmitter power per data rate table of the first node is to be performed periodically.
6. The method of claim 1 , wherein transmitting the transmitter EVM per transmitter power table of the first node comprises:
updating the transmitter EVM per transmitter power table of the first node based at least in part on a temperature variation of the first node; and
transmitting the transmitter EVM per transmitter power table of the first node to the second node.
7. The method of claim 1 , wherein the transmitter and/or receiver characteristics of the second node comprise at least one member selected from the group consisting of the transmitter power per data rate table of the second node and the transmitter error vector magnitude (EVM) per transmitter power table of the second node; and wherein adapting the data rate from the first node to the second node comprises:
estimating an uplink channel of the first node;
transposing the estimated uplink channel of the first node to estimate a downlink channel of the first node;
adjusting the first post-detection SNR per rate of the second node for a received data rate based at least in part on the transmitter power per data rate table of the second node; and
selecting one of the plurality of data rates as the data rate from the first node to the second node based at least in part on the receiver sensitivity per data rate table of the second node.
8. The method of claim 7 , further comprising:
adjusting the first post-detection SNR of the second node for each of the plurality of data rates based at least in part on the transmitter EVM per transmitter power table of the first node and the transmitter EVM per transmitter power table of the second node.
9. The method of claim 7 , wherein selecting the one of the plurality of data rates comprises identifying one of the plurality of data rates having an estimated post-detection SNR that is larger than a threshold SNR.
10. The method of claim 1 , wherein the adapted data rate is a function of at least one transmitter of the first node, a channel from the first node to the second node, and at least one receiver of the second node.
11. The method of claim 1 , wherein the adapted data rate is a function of at least one transmitter of the second node, a channel from the second node to the first node, and at least one receiver of the first node.
12. A communications device for adapting a rate in a multiple-input multiple-output (MIMO) system, comprising a transceiver to:
receive, by a first node, from a second node, transmitter and/or receiver characteristics of the second node, the transmitter and/or receiver characteristics of the second node comprising at least one member selected from the group consisting of: a transmitter power per data rate table of the second node, a transmitter error vector magnitude (EVM) per transmitter power table of the second node, and a receiver sensitivity per data rate table of the second node including a first post-detection signal-to-noise ratio (SNR) per rate for a first packet error rate (PER);
transmit, by the first node, to the second node, transmitter and/or receiver characteristics of the first node, the transmitter and/or receiver characteristics of the first node comprising at least one member selected from the group consisting of: a transmitter power per data rate table of the first node, a transmitter EVM per transmitter power table of the first node, and a receiver sensitivity per data rate table including a second post-detection SNR per rate for a second PER of the first node; and
adapt, by the first node, a data rate from the first node to the second node based at least in part on the transmitter and/or receiver characteristics of the first node and the transmitter and/or receiver characteristics of the second node.
13. The communications device of claim 12 , the transceiver is further to:
after transmitting transmitter and/or receiver characteristics of the first node to the second node, receive, by the first node, information from the second node at an adapted data rate from the second node to the first node, wherein the adapted data rate from the second node to the first node is based at least in part on the transmitter and/or receiver characteristics of the first node and the transmitter and/or receiver characteristics of second node.
14. The communications device of claim 12 , the transceiver is further to:
adjust the transmitter power per data rate table of the first node based at least in part on a received signal strength indicator (RSSI);
wherein the transceiver transmits the transmitter power per data rate table of the first node to the second node upon adjusting the transmitter power per data rate table of the first node.
15. The communications device of claim 12 , wherein the transceiver transmits the transmitter power per data rate table of the first node to the second node during an initial link setup between the first node and the second node.
16. The communications device of claim 14 , wherein the transceiver adjusts the transmitter power per data rate table of the first node periodically.
17. The communications device of claim 12 , wherein the transceiver transmits the transmitter EVM per transmitter power table of the first node by:
updating the transmitter EVM per transmitter power table of the first node based at least in part on a temperature variation of the first node; and
transmitting the transmitter EVM per transmitter power table of the first node to the second node.
18. The communications device of claim 12 , wherein the transmitter and/or receiver characteristics of the second node comprises at least one member selected from the group consisting of the transmitter power per data rate table of the second node and the transmitter error vector magnitude (EVM) per transmitter power table of the second node; and wherein the transceiver adapts the data rate by:
estimating an uplink channel of the first node;
transposing the estimated uplink channel of the first node to estimate a downlink channel of the first node;
adjusting the first post-detection SNR of the second node for a received data rate based at least in part on the transmitter power per data rate table of the second node; and
selecting one of the plurality of data rates as the data rate from the first node to the second node based at least in part on the receiver sensitivity per data rate table of the second node.
19. The communications device of claim 18 , the transceiver is further to:
adjust the first post-detection SNR of the second node for each of the plurality of data rates based at least in part on the transmitter EVM per transmitter power table of the first node and the transmitter EVM per transmitter power table of the second node.
20. The communications device of claim 18 , wherein the transceiver selects the one of the plurality of data rates by identifying one of the plurality of data rates having an estimated post-detection SNR that is larger than a threshold SNR.
21. The communications device of claim 12 , wherein the adapted data rate is a function of at least one transmitter of the first node, a channel from the first node to the second node, and at least one receiver of the second node.
22. The communications device of claim 12 , wherein the adapted data rate is a function of at least one transmitter of the second node, a channel from the second node to the first node, and at least one receiver of the first node.
23. A non-transitory computer-readable medium storing instructions executable by a processor to cause a device to:
receive, by a first node, from a second node, transmitter and/or receiver characteristics of the second node, the transmitter and/or receiver characteristics of the second node comprising at least one member selected from the group consisting of: a transmitter power per data rate table of the second node, a transmitter error vector magnitude (EVM) per transmitter power table of the second node, and a receiver sensitivity per data rate table of the second node including a first post-detection signal-to-noise ratio (SNR) per rate for a first packet error rate (PER);
transmit, by the first node, to the second node, transmitter and/or receiver characteristics of the first node, the transmitter and/or receiver characteristics of the first node comprising at least one member selected from the group consisting of: a transmitter power per data rate table of the first node, a transmitter EVM per transmitter power table of the first node, and a receiver sensitivity per data rate table of the first node including a second post-detection SNR per rate for a second PER; and
adapt, by the first node, a data rate from the first node to the second node based at least in part on the transmitter and/or receiver characteristics of the first node and the transmitter and/or receiver characteristics of the second node.
24. The non-transitory computer-readable medium of claim 23 , wherein the instructions further comprise instructions executable by the processor to cause the device to:
after transmitting transmitter and/or receiver characteristics of the first node to the second node, receive, by the first node, information from the second node at an adapted data rate from the second node to the first node, wherein the adapted data rate from the second node to the first node is based at least in part on the transmitter and/or receiver characteristics of the first node and the transmitter and/or receiver characteristics of second node.
25. The non-transitory computer-readable medium of claim 23 , wherein the instructions further comprise instructions executable by the processor to cause the device to:
adjust the transmitter power per data rate table of the first node based at least in part on a received signal strength indicator (RSSI);
wherein the instructions executable by the processor to cause the device to transmit the transmitter and/or receiver characteristics of the first node comprise instructions executable by the processor to cause the device to transmit the transmitter power per data rate table of the first node to the second node upon adjusting the transmitter power per data rate table of the first node.
26. The non-transitory computer-readable medium of claim 23 , wherein the instructions executable by the processor to cause the device to transmit the transmitter and/or receiver characteristics of the first node comprise instructions executable by the processor to cause the device to transmit the transmitter power per data rate table of the first node to the second node during an initial link setup between the first node and the second node.
27. The non-transitory computer-readable medium of claim 23 , wherein the instructions executable by the processor to cause the device to transmit the transmitter EVM per transmitter power table of the first node comprise instructions executable by the processor to cause the device to:
update the transmitter EVM per transmitter power table of the first node based at least in part on a temperature variation of the first node; and
transmit the transmitter EVM per transmitter power table of the first node to the second node.
28. The non-transitory computer-readable medium of claim 23 , wherein the transmitter and/or receiver characteristics of the second node comprises at least one member selected from the group consisting of the transmitter power per data rate table of the second node and the transmitter error vector magnitude (EVM) per transmitter power table of the second node; and wherein the instructions executable by the processor to cause the device to adapt the data rate from the first node to the second node based at least in part on the transmitter and/or receiver characteristics of the first node and the transmitter and/or receiver characteristics of the second node comprise instructions executable by the processor to cause the device to:
estimate an uplink channel of the first node;
transpose the estimated uplink channel of the first node to estimate a downlink channel of the first node;
adjust the first post-detection SNR of the second node for a received data rate based at least in part on the transmitter power per data rate table of the second node; and
select one of the plurality of data rates as the data rate from the first node to the second node based at least in part on the receiver sensitivity per data rate table of the second node.
29. The non-transitory computer-readable medium of claim 28 , wherein the instructions further comprise instructions executable by the processor to cause the device to:
adjust the first post-detection SNR of the second node for each of the plurality of data rates based at least in part on the transmitter EVM per transmitter power table of the first node and the transmitter EVM per transmitter power table of the second node.
30. The non-transitory computer-readable medium of claim 28 , wherein the instructions further comprise instructions executable by the processor to cause the device to:
select the one of the plurality of data rates by identifying one of the plurality of data rates having an estimated post-detection SNR that is larger than a threshold SNR.