Uplink interference management in shared spectrum networks

Abstract

A network control system for a first wireless network may include a network control circuit configured to manage radio communications of the first wireless network, where the network control circuit is further configured to estimate a proximity to a second wireless network for a plurality of user terminals based on a measurement of the second wireless network reported by the plurality of user terminals, determine whether the second wireless network is experiencing excessive interference from the first wireless network, and if the second wireless network is experiencing excessive interference from the first wireless network, adjust a transmit power allocation of one or more selected user terminals of the plurality of user terminals based on the estimated proximity to the second wireless network for the one or more selected user terminals.

1 . A network control system for a shared spectrum first wireless network comprising a network control circuit configured to manage radio communications of a first wireless network, the network control circuit further configured to:
 estimate a proximity to a second wireless network for a plurality of user terminals based on a measurement of the second wireless network reported by the plurality of user terminals; wherein the plurality of user terminals utilize a frequency band of the first wireless network that is substantially similar to a frequency band of the second wireless network;   select one or more measurement terminals from the plurality of user terminals based on the estimated proximity of the plurality of user terminals; and   receive one or more interference measurements from the one or more measurement terminals that indicate interference to the second wireless network related to the first wireless network.   
     
     
         2 . The network control system of  claim 1 , wherein the network control circuit is configured to select one or more measurement terminals from the plurality of user terminals based on the estimated proximity of the plurality of user terminals by:
 selecting one or more of the plurality of user terminals that report the strongest measurements of the second wireless network as the one or more measurement terminals.   
     
     
         3 . The network control system of  claim 1 , wherein the network control circuit is configured to estimate a proximity to a second wireless network for a plurality of user terminals based on a measurement of the second wireless network reported by the plurality of user terminals by:
 determining that one or more first user terminals of the plurality of user terminals that report strong measurements are located closer to the second wireless network than one or more second user terminals of the plurality of user terminals that report weak measurements.   
     
     
         4 . The network control system of  claim 1 , wherein the measurement of the second wireless network reported by the plurality of user terminals is a signal power measurement of the second wireless network,
 and wherein the network control circuit is configured to estimate a proximity to a second wireless network for a plurality of user terminals based on a measurement of the second wireless network reported by the plurality of user terminals by performing at least one of:   ranking the plurality of user terminals according to the signal power measurement reported by the plurality of user terminals;   comparing a signal power measurement reported by a first user terminal of the plurality of user terminals to a signal power measurement reported by a second user terminal of the plurality of user terminals;   comparing the signal power measurement reported by the plurality of user terminals to a signal power threshold; or   calculating an approximate proximity from the second wireless network based on the signal power measurement.   
     
     
         5 . The network control system of  claim 1 , wherein the network control circuit is further configured to determine whether to perform uplink power control based on the one or more interference measurements. 
     
     
         6 . The network control system of  claim 5 , wherein the network control circuit is configured to determine whether to perform uplink power control based on the one or more interference measurements by:
 determining to perform uplink power control if the one or more interference measurements indicate excessive interference to the second wireless network.   
     
     
         7 . The network control system of  claim 6 , wherein the network control circuit is further configured to select one or more target user terminals from the plurality of user terminals to reduce allocated uplink transmit power based on the estimated proximity of the one or more target user terminals from the second wireless network. 
     
     
         8 . The network control system of  claim 5 , wherein the network control circuit is configured to determine whether to perform uplink power control based on the one or more interference measurements by:
 comparing the one or more interference measurements to a predetermined interference threshold; and   determining to perform uplink power control if the one or more interference measurements satisfy the predetermined interference threshold.   
     
     
         9 . The network control system of  claim 1 , wherein the measurement of the second wireless network reported by a first user terminal of the plurality of user terminals is a signal power measurement that indicates a signal power of a signal received by the first user terminal from the second wireless network. 
     
     
         10 . A network control system for a shared spectrum wireless network comprising a network control circuit configured to manage radio communications of a first wireless network, the network control circuit further configured to:
 estimate a proximity to a second wireless network for a plurality of user terminals based on a measurement of the second wireless network reported by the plurality of user terminals; wherein the plurality of user terminals utilize a frequency band of the first wireless network that is substantially similar to a frequency band of the second wireless network;   determine whether the second wireless network is experiencing excessive interference from the first wireless network; and   if the second wireless network is experiencing excessive interference from the first wireless network, adjust a transmit power allocation of one or more selected user terminals of the plurality of user terminals based on the estimated proximity to the second wireless network for the one or more selected user terminals.   
     
     
         11 . The network control system of  claim 10 , wherein the network control circuit is further configured to select the one or more selected user terminals from the plurality of user terminals based on which of the plurality of user terminals have close estimated proximities to the second wireless network. 
     
     
         12 . The network control system of  claim 10 , wherein the network control circuit is configured to adjust a transmit power allocation of one or more selected user terminals of the plurality of user terminals based on the estimated proximity to the second wireless network for the one or more selected user terminals by:
 selecting one or more user terminals of the plurality of user terminals that have close estimated proximities to the second wireless network as the one or more selected user terminals; and   reducing the transmit power allocation of the one or more selected user terminals.   
     
     
         13 . The network control system of  claim 10 , wherein the network control circuit is further configured to receive one or more interference measurements from one or more measurement terminals,
 and wherein the network control circuit is configured to determine whether the second wireless network is experiencing excessive interference from the first wireless network by:   determining whether the second wireless network is experiencing excessive interference from the first wireless network based on the one or more interference measurements.   
     
     
         14 . The network control system of  claim 13 , wherein the network control circuit is further configured to:
 select one or more measurement terminals from the plurality of user terminals; and   receive one or more one or more interference measurements from one or more measurement terminals,   and wherein the network control circuit is configured to determine whether the second wireless network is experiencing excessive interference from the first wireless network by:   determining whether the second wireless network is experiencing excessive interference from the first wireless network based on the one or more interference measurements.   
     
     
         15 . The network control system of  claim 14 , wherein the network control circuit is configured to select one or more measurement terminals from the plurality of user terminals by:
 selecting the one or more measurement terminals from the plurality of user terminals based on the estimated proximity to the second wireless network for the one or more measurement terminals.   
     
     
         16 . The network control system of  claim 10 , wherein the network control circuit is configured to adjust a transmit power allocation of one or more selected user terminals of the plurality of user terminals based on the estimated proximity to the second wireless network for the one or more selected user terminals by:
 selecting one or more user terminals of the plurality of user terminals that report the strongest measurements of the second wireless network as the one or more selected terminals; and   reducing the transmit power allocation of the one or more selected user terminals.   
     
     
         17 . The network control system of  claim 10 , wherein the network control circuit is configured to estimate a proximity to a second wireless network for a plurality of user terminals based on a measurement of the second wireless network reported by the plurality of user terminals by:
 estimating the proximity to the second wireless network for the plurality of user terminals relative to the proximity of the other user terminals of the plurality of user terminals to the second wireless network based on the measurement of the second wireless network reported by the plurality of user terminals.   
     
     
         18 . The network control system of  claim 10 , wherein the first wireless network is a licensee in a spectrum sharing system and the second wireless network is an incumbent in the spectrum sharing system. 
     
     
         19 . The network control system of  claim 18 , wherein the spectrum sharing system is a Licensed Shared Access (LSA) system or a Spectrum Access System (SAS) system. 
     
     
         20 . A mobile terminal comprising a radio processing circuit and a baseband processing circuit configured to interact with the radio processing circuit to transmit and receive radio signals, the baseband processing circuit further configured to:
 receive a composite signal comprising a first received signal from a first wireless network and a second received signal from a second wireless network;   calculate a correlation between the composite signal and a local reference signal to determine a signal power measurement of the second received signal;   report the signal power measurement to the first wireless network as a measurement report; and   receive control signaling in response to the measurement report that specifies an assigned operation configuration for the user terminal.   
     
     
         21 . The mobile terminal of  claim 20 , wherein the baseband processing circuit is configured to receive control signaling in response to the measurement report that specifies an operation assignment for the user terminal by:
 receiving a measurement operation assignment,   the baseband processing circuit further configured to:   perform an interference measurement that indicates interference to the second wireless network; and   report the interference measurement to the first wireless network.   
     
     
         22 . The mobile terminal of  claim 20 , wherein the baseband processing circuit is configured to receive control signaling in response to the measurement report that specifies an operation assignment for the user terminal by:
 receiving a transmit power operation assignment that specifies a transmit power,   the baseband processing circuit further configured to:   transmit signals according to the transmit power.   
     
     
         23 . The mobile terminal of  claim 20 , wherein the baseband processing circuit is configured to calculate a correlation between the composite signal and a local reference signal to determine a signal power measurement of the second received signal by:
 calculating a cross-correlation between the composite signal and the local reference signal to obtain a reference signal channel response;   calculating a reference signal power measurement from the reference signal channel response; and   subtracting the reference signal power measurement from a signal power measurement of the composite signal to obtain the signal power measurement of the second received signal.   
     
     
         24 . The mobile terminal of  claim 20 , wherein the first received signal comprises a downlink reference signal transmitted by a transmission point of the first wireless network. 
     
     
         25 . The mobile terminal of  claim 20 , wherein the first wireless network is a licensee in a spectrum sharing system and the second wireless network is an incumbent in the spectrum sharing system.