Transmitter-based link adaptation
This disclosure provides methods, devices and systems for link adaptation in wireless communications. Some implementations more specifically relate to transmitter-based modulation and coding scheme (MCS) selection. A transmitting device transmits a test packet, over a wireless channel, to a receiving device. The receiving device generates one or more signal-to-interference-plus-noise ratio (SINR) estimates for the wireless channel based on the received sounding packet. In some aspects, each SINR estimate may be associated with a particular modulation order. In some other aspects, each SINR estimate may be generated based on a transmitter configuration or a receiver type to be used for subsequent communications between the transmitting device and the receiving device. The receiving device transmits feedback, including the SINR estimates, to the transmitting device. The transmitting device then selects an MCS to be used for subsequent communications with the receiving device based on the SINR estimates and associated modulation orders.
1 . A method for wireless communication performed by a wireless communication device associated with a wireless local area network (WLAN), comprising:
transmitting a first packet, over a wireless channel associated with the WLAN, to a receiving device associated with the WLAN;
receiving feedback from the receiving device responsive to the first packet, the feedback including one or more signal-to-interference-plus-noise ratio (SINR) estimates associated with the wireless channel, wherein the feedback further includes, for each SINR estimate of the one or more SINR estimates, an indication identifying, from among a plurality of modulation orders, which modulation order the each SINR estimate is calculated according to; and
selecting a modulation and coding scheme (MCS) to be used for subsequent communications with the receiving device based on the one or more SINR estimates and the respective modulation order associated with each of the one or more SINR estimates.
2 . The method of claim 1 , further comprising:
transmitting a second packet to the receiving device in accordance with the selected MCS, the second packet being transmitted over a number (N) of spatial streams.
3 . The method of claim 2 , wherein the first packet is transmitted over the N spatial streams.
4 . The method of claim 2 , wherein the first packet is transmitted over a different number (M) of spatial streams than the second packet.
5 . The method of claim 4 , further comprising:
transmitting a third packet to the receiving device prior to the transmission of the first packet, the third packet carrying information indicating the N spatial streams.
6 . The method of claim 5 , wherein the first packet is a null data packet (NDP) and the third packet is an NDP announcement (NDPA) associated with the NDP.
7 . The method of claim 1 , wherein the one or more SINR estimates comprises a plurality of SINR estimates, each of the plurality of SINR estimates being associated with a different modulation order.
8 . The method of claim 7 , further comprising:
determining an arrangement of the plurality of SINR estimates in the received feedback, the respective modulation order associated with each SINR estimate being determined based on the arrangement of the plurality of SINR estimates.
9 . The method of claim 7 , wherein the selecting of the MCS comprises:
estimating a respective throughput of communications associated with each of the plurality of SINR estimates based on the respective modulation order upon which each SINR estimate is based at least in part, the MCS being selected based on the estimated throughputs associated with the plurality of SINR estimates.
10 . A wireless communication device associated with a wireless local area network (WLAN), comprising:
at least one modem;
at least one processor communicatively coupled with the at least one modem; and
at least one memory communicatively coupled with the at least one processor and storing processor-readable code that, when executed by the at least one processor in conjunction with the at least one modem, is configured to:
transmit a first packet, over a wireless channel associated with the WLAN, to a receiving device associated with the WLAN;
receive feedback from the receiving device responsive to the first packet, the feedback including one or more signal-to-interference-plus-noise ratio (SINR) estimates associated with the wireless channel, wherein the feedback further includes, for each SINR estimate of the one or more SINR estimates, an indication identifying, from among a plurality of modulation orders, which modulation order the each SINR estimate is calculated according to; and
select a modulation and coding scheme (MCS) to be used for subsequent communications with the receiving device based on the one or more SINR estimates and the respective modulation order associated with each of the one or more SINR estimates.
11 . The wireless communication device of claim 10 , wherein execution of the processor-readable code is further configured to:
transmit a second packet to the receiving device in accordance with the selected MCS, the second packet being transmitted over a number (N) of spatial streams.
12 . The wireless communication device of claim 11 , wherein the first packet is transmitted over the N spatial streams.
13 . The wireless communication device of claim 11 , wherein the first packet is transmitted over a different number (M) of spatial streams than the second packet.
14 . The wireless communication device of claim 13 , wherein execution of the processor-readable code is further configured to:
transmit a third packet to the receiving device prior to the transmission of the first packet, the third packet carrying information indicating the N spatial streams.
15 . The wireless communication device of claim 14 , wherein the first packet is a null data packet (NDP) and the third packet is an NDP announcement (NDPA) associated with the NDP.
16 . The wireless communication device of claim 10 , wherein the one or more SINR estimates comprises a plurality of SINR estimates, each of the plurality of SINR estimates being associated with a different modulation order.
17 . The wireless communication device of claim 16 , wherein execution of the processor-readable code is further configured to:
determine an arrangement of the plurality of SINR estimates in the received feedback, the respective modulation order upon which each SINR estimate is based at least in part being determined based on the arrangement of the plurality of SINR estimates.
18 . A method for wireless communication performed by a wireless communication device associated with a wireless local area network (WLAN), comprising:
receiving a first packet, over a wireless channel associated with the WLAN, from a transmitting device associated with the WLAN;
determining a receiver type to be used for receiving subsequent communications from the transmitting device;
generating one or more signal-to-interference-plus-noise ratio (SINR) estimates associated with the wireless channel based on the reception of the first packet and the receiver type to be used for receiving the subsequent communications; and
transmitting, to the transmitting device, feedback including at least one of the one or more SINR estimates, wherein the feedback further includes, for each SINR estimate of the one or more SINR estimates, an indication identifying, from among a plurality of modulation orders, which modulation order the each SINR estimate is calculated according to.