Adaptive multiple antenna transmission scheme for uplink data transmission in wireless communication systems

Abstract

The described technology is generally directed towards adaptively changing which transmission scheme a user equipment is to use based on a Doppler metric (e.g., Doppler frequency) as evaluated against a threshold Doppler value. A network instructs a user equipment to use a Rank-1 precoder cycling transmission scheme if the Doppler metric of user equipment is above a threshold value, or to use a closed loop MIMO transmission scheme if the user equipment has a Doppler metric below the threshold value. The network can instruct the user equipment via a suitable message, or by switching off TPMI and notifying the user equipment thereof.

What is claimed is: 
     
         1 . A method, comprising:
 determining, by network equipment comprising a processor, a rate of change of speed of movement of a user equipment during a time period; and   adjusting, by the network equipment, a threshold speed applicable to changing a current transmission scheme of the user equipment based on the rate of change of the speed of movement of the user equipment, resulting in an adjusted threshold speed.   
     
     
         2 . The method of  claim 1 , further comprising, in response to determining that the current transmission scheme is a closed loop multiple input multiple output transmission scheme, and that a current speed of movement of the user equipment is above the adjusted threshold speed, transmitting, by the network equipment, to the user equipment, a recommendation to change the current transmission scheme to a rank-1 precoder cycling transmission scheme. 
     
     
         3 . The method of  claim 1 , further comprising, in response to determining that the current transmission scheme is a rank-1 precoder cycling transmission scheme, and that a current speed of movement of the user equipment is below the adjusted threshold speed, transmitting, by the network equipment, to the user equipment, a recommendation to change the current transmission scheme to a closed loop multiple input multiple output transmission scheme. 
     
     
         4 . The method of  claim 1 , wherein the adjusting comprises:
 in response to the rate of change of the speed of movement of the user equipment corresponding to an increasing rate of change of the speed of movement of the user equipment, selecting, by the network equipment, a first speed as the adjusted threshold speed, and   in response to the rate of change of the speed of movement of the user equipment corresponding to a decreasing rate of change of the speed of movement of the user equipment, selecting, by the network equipment, a second speed as the adjusted threshold speed.   
     
     
         5 . The method of  claim 1 , further comprising determining, by the network equipment, the rate of change of the speed of movement of the user equipment during the time period based on uplink channel estimates. 
     
     
         6 . The method of  claim 1 , further comprising determining, by the network equipment, the rate of change of the speed of movement of the user equipment during the time period as a function of downlink channel quality information. 
     
     
         7 . The method of  claim 1 , wherein the current transmission scheme is employed with new radio transmissions. 
     
     
         8 . Network equipment, comprising:
 a processor; and   a memory that stores executable instructions that, when executed by the processor, facilitate performance of operations, comprising:
 determining a rate of change of speed of movement of a user equipment during a time period; and 
 modifying a threshold speed for changing a current transmission scheme of the user equipment based on the rate of change of the speed of movement of the user equipment, resulting in a modified threshold speed. 
   
     
     
         9 . The network equipment of  claim 8 , wherein the operations further comprise, in response to determining that the current transmission scheme is a closed loop multiple input multiple output transmission scheme, and that a current speed of movement of the user equipment is above the modified threshold speed, modifying the current transmission scheme to a rank-1 precoder cycling transmission scheme. 
     
     
         10 . The network equipment of  claim 8 , wherein the operations further comprise, in response to determining that the current transmission scheme is a rank-1 precoder cycling transmission scheme, and that a current speed of movement of the user equipment is below the modified threshold speed, modifying the current transmission scheme to a closed loop multiple input multiple output transmission scheme. 
     
     
         11 . The network equipment of  claim 8 , wherein the modifying comprises:
 in response to the rate of change of the speed of movement of the user equipment corresponding to an increasing rate of change of the speed of movement of the user equipment, selecting a first speed as the modified threshold speed, and   in response to the rate of change of the speed of movement of the user equipment corresponding to a decreasing rate of change of the speed of movement of the user equipment, selecting a second speed as the modified threshold speed, the second speed being different than the first speed.   
     
     
         12 . The network equipment of  claim 8 , wherein the operations further comprise determining the rate of change of the speed of movement of the user equipment during the time period based on uplink channel estimates. 
     
     
         13 . The network equipment of  claim 8 , wherein the operations further comprise determining the rate of change of the speed of movement of the user equipment during the time period as a function of downlink channel quality information. 
     
     
         14 . The network equipment of  claim 8 , wherein the current transmission scheme is employed with multiple input multiple output transmissions. 
     
     
         15 . A non-transitory machine-readable medium, comprising executable instructions that, when executed by a processor, facilitate performance of operations, comprising:
 determining a rate of change of speed of movement of a user equipment during a time period; and   changing a threshold speed associated with changing a current transmission scheme of the user equipment based on the rate of change of the speed of movement of the user equipment, resulting in a changed threshold speed.   
     
     
         16 . The non-transitory machine-readable medium of  claim 15 , wherein the operations further comprise, in response to determining that the current transmission scheme is a closed loop multiple input multiple output transmission scheme, and that a current speed of movement of the user equipment is above the changed threshold speed, instructing the user equipment to change the current transmission scheme to a rank-1 precoder cycling transmission scheme. 
     
     
         17 . The non-transitory machine-readable medium of  claim 15 , wherein the operations further comprise, in response to determining that the current transmission scheme is a rank-1 precoder cycling transmission scheme, and that a current speed of movement of the user equipment is below the changed threshold speed, instructing the user equipment to change the current transmission scheme to a closed loop multiple input multiple output transmission scheme. 
     
     
         18 . The non-transitory machine-readable medium of  claim 15 , wherein the changing comprises:
 in response to the rate of change of the speed of movement of the user equipment being determined to correspond to an increasing rate of change of the speed of movement of the user equipment, selecting a first speed as the changed threshold speed, and   in response to the rate of change of the speed of movement of the user equipment being determined to correspond to a decreasing rate of change of the speed of movement of the user equipment, selecting a second speed as the changed threshold speed.   
     
     
         19 . The non-transitory machine-readable medium of  claim 15 , wherein the operations further comprise determining the rate of change of the speed of movement of the user equipment during the time period based on uplink channel estimates. 
     
     
         20 . The non-transitory machine-readable medium of  claim 15 , wherein the operations further comprise determining the rate of change of the speed of movement of the user equipment during the time period as a function of downlink channel quality information.