Methods and apparatus for mitigating fading in a broadband access system using drone/uav platforms

Abstract

Systems and methods for mitigating the effects of atmospheric conditions such as rain, fog, cloud in a broadband access system using drone/UAVs. In one embodiment, terminal and drone radio and transmission medium fixture sub-systems comprise multiple transmission media. In one embodiment, in response to changes in atmospheric conditions the drone radio sub-system switches transmission medium to reduce the effects of atmospheric conditions. In another embodiment, the terminal and drone radio sub-systems equalize the data rates among terminals in response to changes in atmospheric conditions observed by different terminals. In another embodiment, the drone radio sub-system adjusts the transmit power on the downlink to different terminal according to fading due to atmospheric conditions on each link.

1 . A drone configured to provide broadband access to one or more terminals, the drone comprising:
 at least one transmission medium fixture comprising a plurality of transmission mediums configured to provide coverage to one or more terminals;   wherein various ones of the plurality of transmission mediums are associated with different resistances to different fading conditions;   at least one radio sub-system configured to:   demodulate and decode one or more first signals received from the one or more terminals; and   modulate and transmit one or more second signals to the one or more terminals; and   a drone switching sub-system configured to switch data received at the drone to another receiving unit of the one or more terminals and/or one or more drones;   wherein the drone switching sub-system is configured to select a transmission medium based on a measured fading condition.   
     
     
         2 . The drone of  claim 1 , wherein:
 the one or more terminals comprise one or more ground-based mobile terminals;   the drone radio sub-system is further configured to determine an amount of transmission resources to be allocated to one or more downlinks of the different ones of the one or more ground-based mobile terminals to equalize a data rate among the different ones of the one or more ground-based mobile terminals according to a fairness criterion; and   the drone switching sub-system further comprises a scheduler, the scheduler configured to schedule the determined amount of transmission resources to the downlink of the different ones of the one or more ground-based mobile terminals.   
     
     
         3 . The drone of  claim 2 , wherein the drone radio sub-system is further configured to:
 determine a change on an uplink signal quality received from different ones of the one or more ground-based mobile terminals due to one or more atmospheric conditions; and   determine an amount of transmission resources to be allocated to an uplink of the different ones of the one or more terminals to equalize a data rate among the different ones of the one or more terminals according to at least one fairness criterion; and   the scheduler is further configured to:   schedule the determined amount of transmission resources to the uplink of the different ones of the one or more terminals; and   inform the different ones of the one or more terminals of respective scheduled transmission resources.   
     
     
         4 .- 5 . (canceled) 
     
     
         6 . The drone of  claim 1 , wherein the drone radio sub-system is further configured to:
 determine a change in an amount of power allocated on a downlink to at least one of the one or more terminals to equalize the data rate among different terminals according to at least one fairness criterion; and   adjust the power allocated to the downlink of to one or more of the one or more terminals.   
     
     
         7 . The drone of  claim 6 , wherein the drone radio sub-system is further configured to:
 encode terminal data;   map the coded bits onto constellation symbols;   scale the coded symbols from each terminal destined to different antenna elements to form a beam toward a respective terminal;   sum the scaled coded symbols for different terminals destined to a same antenna aperture to form multiple beams, one toward each respective terminal;   modulate the resulting symbols onto the selected transmission medium and   transmit the resulting signal through the corresponding antenna aperture.   
     
     
         8 . The drone of  claim 7 , wherein the drone radio subsystem is further configured to choose the scale for coded symbols for each terminal to adjust the power sent to a terminal on the respective downlink. 
     
     
         9 . A method of providing broadband access using a plurality of drones, the method comprising:
 measuring a signal quality metric for one or more terminals of a plurality of terminals;   comparing the measured signal quality metric versus one or more threshold values;   determining if the signal quality metric of the one or more terminals has degraded due to one or more atmospheric conditions; and   select a different transmission medium when the signal quality metric of the one or more terminals has degraded.   
     
     
         10 . The method of  claim 9 , further comprising:
 determining a number of transmission resources that an uplink and downlink to the one or more terminal needs in order to equalize the throughput to different ones of the plurality of terminals according to a specified fairness criterion;   informing a scheduler of the allocated number of transmission resources for a terminal link of the one or more terminals; and   sending a message to one or more terminals comprising respective uplink transmission resource allocations.   
     
     
         11 . The method of  claim 9 , further comprising switching to a second transmission medium to mitigate atmospheric-related fading. 
     
     
         12 . The method of  claim 9  further comprising adjusting a power allocated to each terminal on a downlink according to a change in the measured signal quality metric. 
     
     
         13 . A mobile terminal, comprising:
 a mobile terminal radio sub-system comprising at least one transmission medium fixture configured to receive data signaling on at least two transmission mediums having different resistance to atmospheric effects, the mobile terminal radio sub-system configured to:   demodulate and decode one or more first signals received on at least one transmission medium of the at least two transmission mediums from at least one of one or more drones;   responsive to a switch instruction, the at least one transmission medium fixture switches to a different transmission medium of the at least two transmission mediums.   
     
     
         14 . The mobile terminal of  claim 13 , wherein the mobile terminal radio sub-system is further configured to:
 measure a received downlink signal quality to determine a signal quality change due to atmospheric conditions; and   send the measured signal quality to the at least one radio sub-system of the one or more drones.   
     
     
         15 . The mobile terminal of  claim 13 , wherein the mobile terminal radio sub-system is further configured to measure a change in a received downlink signal quality to determine a signal quality change due to one or more atmospheric conditions; and
 send the measured change in a received downlink signal quality to the drone radio sub-system.   
     
     
         16 . The mobile terminal of  claim 13 , wherein the mobile terminal radio sub-system is further configured to:
 measure a received downlink signal quality to determine a change in signal quality due to one or more atmospheric conditions; and   send the measured signal quality to at least one drone.   
     
     
         17 . The mobile terminal of  claim 13 , wherein the one or more atmospheric conditions are selected from the group consisting of: (i) fog, (ii) clouds, and (iii) rain. 
     
     
         18 . (canceled) 
     
     
         19 . The mobile terminal of  claim 13 , wherein the mobile terminal radio sub-system is further configured to:
 receive a schedule of transmission resources to use for communication with at least one drone; and   configure communication to the at least one drone based on the received schedule.   
     
     
         20 . The mobile terminal of  claim 13 , wherein the measured signal quality comprises a signal to interference plus noise ratio (SINR).