Expand dynamic of tdd signal detection and expand robustness against volatile signals

Abstract

A method for operating a switching control module of TDD switching sub-system includes determining whether current clock time is within a time window of an expected transition from downlink to uplink, the expected transition from downlink to uplink based on a clock setting; when current clock time is within the time window, monitoring a signal indicative of whether a measured power of the downlink signal on a downlink path exceeds a threshold power; when the signal indicates the measured power of the downlink signal does not exceed the threshold power, determining whether filter period has passed without the signal indicating the measured power of the downlink signal exceeds the threshold power; when the filter period has passed without the signal indicating the measured power of the downlink signal exceeds the threshold power, determine an end time of the downlink signal; updating the clock setting based on the determined end time.

What is claimed is: 
     
         1 . A method for operating a switching control module of a time-division-duplexing (TDD) switching sub-system comprising:
 determining whether a current clock time is within a predetermined time window of an expected transition from a downlink signal to an uplink signal, wherein the expected transition from the downlink signal to the uplink signal is based on a clock setting;   when the current clock time is within the predetermined time window of an expected transition from the downlink signal to the uplink signal, monitoring a signal indicative of whether a measured signal power of the downlink signal on a downlink path exceeds a threshold signal power;   when the signal indicates that the measured signal power of the downlink signal does not exceed the threshold signal power, determining whether a filter time period has passed without the signal indicating that the measured signal power of the downlink signal exceeds the threshold signal power;   when the filter time period has passed without the signal indicating that the measured signal power of the downlink signal exceeds the threshold signal power, determine an end time of the downlink signal; and   updating the clock setting based on the determined end time of the downlink signal.   
     
     
         2 . The method of  claim 1 , further comprising:
 measuring a signal power of the downlink signal on the downlink path using a measurement receiver; and   comparing the measured signal power of the downlink signal on the downlink path to the threshold signal power using a comparator, wherein the signal indicative of whether a measured signal power of the downlink signal on the downlink path exceeds the threshold signal power is output from the comparator.   
     
     
         3 . The method of  claim 1 , wherein the predetermined time window is a fixed time from an expected time for the expected transition from the downlink signal to the uplink signal. 
     
     
         4 . The method of  claim 1 , wherein the filter time period is based on a length of one symbol. 
     
     
         5 . The method of  claim 1 , wherein the TDD switching sub-system is included in a remote antenna unit of a distributed antenna system (DAS), the method comprising disconnecting an antenna from the downlink path in the remote antenna unit of the DAS by switching at least one switch of the downlink path in the remote antenna unit of the DAS and communicatively coupling the antenna to an uplink path in the remote antenna unit of the DAS by switching at least one switch of the uplink path in the remote antenna unit of the DAS. 
     
     
         6 . The method of  claim 1 , wherein the TDD switching sub-system is included in a single-node repeater, the method comprising disconnecting the antenna from the downlink path of the single-node repeater by switching at least one switch of the downlink path of the single-node repeater and communicatively coupling the antenna to an uplink path single-node repeater by switching at least one switch of the uplink path of the single-node repeater. 
     
     
         7 . The method of  claim 1 , further comprising determining a start time of the downlink signal and updating the clock setting based on the determined start time of the downlink signal. 
     
     
         8 . A switching control module comprising:
 a measurement receiver configured to measure a signal power of a downlink signal in a downlink path of a telecommunication system;   at least one processor configured to:
 determine whether a current clock time is within a predetermined time window of an expected transition from a downlink signal to an uplink signal, wherein the expected transition from the downlink signal to the uplink signal is based on a clock setting; 
 when the current clock time is within the predetermined time window of an expected transition from the downlink signal to the uplink signal, monitor a signal that is indicative of whether the measured signal power of the downlink signal on the downlink path exceeds the threshold signal power; 
 when the signal indicates that the measured signal power of the downlink signal does not exceed the threshold signal power, determine whether a filter time period has passed without the signal indicating that the measured signal power of the downlink signal exceeds the threshold signal power; and 
 when the filter time period has passed without the signal indicating that the measured signal power of the downlink signal exceeds the threshold signal power, determine an end time of the downlink signal; and 
 update the clock setting based on the determined end time of the downlink signal. 
   
     
     
         9 . The switching control module of  claim 8 , further comprising a comparator having an input communicatively coupled to the measurement receiver and an output communicatively coupled to the at least one processor, wherein the comparator is configured to compare the threshold signal power with the measured signal power of the downlink signal received from the measurement receiver via the input, wherein the comparator is configured to provide the signal that is indicative of whether the measured signal power exceeds the threshold signal power to the at least one processor via the output. 
     
     
         10 . The switching control module of  claim 8 , wherein the at least one processor receives the measured signal power from the measurement receiver, wherein the at least one processor is configured to compare the threshold signal power with the measured signal power of the downlink signal received from the measurement receiver, wherein the at least one processor is configured to generate the signal that is indicative of whether the measured signal power of the downlink signal on the downlink path exceeds the threshold signal power. 
     
     
         11 . The switching control module of  claim 8 , wherein the predetermined time window is a fixed time from the expected time for the transition from the downlink signal to the uplink signal. 
     
     
         12 . The switching control module of  claim 8 , wherein the filter time period is based on a length of one symbol. 
     
     
         13 . The switching control module of  claim 8 , wherein the switching control module is included in a remote antenna unit of a distributed antenna system (DAS), wherein the at least one processor is configured to disconnect an antenna from the downlink path in the remote antenna unit of the DAS by switching at least one switch of the downlink path in the remote antenna unit of the DAS and communicatively couple the antenna to an uplink path in the remote antenna unit of the DAS by switching at least one switch of the uplink path in the remote antenna unit of the DAS. 
     
     
         14 . The switching control module of  claim 8 , wherein the switching control module is included in a single-node repeater, wherein the at least one processor is configured to disconnect an antenna from the downlink path of the single-node repeater by switching at least one switch of the downlink path of the single-node repeater and communicatively couple the antenna to an uplink path of the single-node repeater by switching at least one switch of the uplink path of the single-node repeater. 
     
     
         15 . The switching control module of  claim 8 , wherein the at least one processor is further configured to determine a start time of the downlink signal and update the clock setting based on the determined start time of the downlink signal. 
     
     
         16 . A time division duplex (TDD) switching sub-system disposed in a remote unit of a telecommunication system, the TDD switching sub-system comprising:
 at least one first switch positioned in a downlink path from a base station to an antenna of the remote unit, the at least one first switch configured to selectively connect the antenna to the downlink path;   at least one second switch positioned in an uplink path from the antenna to the base station, the at least one second switch configured to selectively connect the antenna to the uplink path;   a measurement receiver configured to measure a signal power in the downlink path;   at least one processor configured to:
 determine whether a current clock time is within a predetermined time window of an expected transition from a downlink signal to an uplink signal, wherein the expected transition from the downlink signal to the uplink signal is based on a clock setting; 
 when the current clock time is within the predetermined time window of an expected transition from the downlink signal to the uplink signal, monitor a output that is indicative of whether the measured signal power of the downlink signal on a downlink path exceeds the threshold signal power; 
 when the signal indicates that the measured signal power of the downlink signal does not exceed the threshold signal power, determine whether a filter time period has passed without the signal indicating that the measured signal power of the downlink signal exceeds the threshold signal power; and 
 when the filter time period has passed without the signal indicating that the measured signal power of the downlink signal exceeds the threshold signal power, determine an end time of the downlink signal; and 
 update the clock setting based on the determined end time of the downlink signal. 
   
     
     
         17 . The TDD switching sub-system of  claim 16 , further comprising a comparator having an input communicatively coupled to the measurement receiver and an output communicatively coupled to the at least one processor, wherein the comparator is configured to compare the threshold signal power with the measured signal power received from the measurement receiver via the input and provide the signal that is indicative of whether the power measurement exceeds the threshold signal power to the at least one processor via the output. 
     
     
         18 . The TDD switching sub-system of  claim 16 , wherein the at least one processor receives the measured signal power from the measurement receiver, wherein the at least one processor is configured to compare the threshold signal power with the measured signal power of the downlink signal received from the measurement receiver, wherein the at least one processor is configured to generate the signal that is indicative of whether the measured signal power of the downlink signal on the downlink path exceeds the threshold signal power. 
     
     
         19 . The TDD switching sub-system of  claim 16 , wherein the predetermined time window is a fixed time from the expected time for the transition from the downlink signal to the uplink signal. 
     
     
         20 . The TDD switching sub-system of  claim 16 , wherein the filter time period is based on a length of one symbol. 
     
     
         21 . The TDD switching sub-system of  claim 16 , wherein the remote unit comprises a remote antenna unit of a distributed antenna system (DAS), wherein the at least one processor is configured to disconnect the antenna from the downlink path in the remote antenna unit of the DAS by switching at least one switch of the downlink path in the remote antenna unit of the DAS and communicatively couple the antenna to an uplink path in the remote antenna unit of the DAS by switching at least one switch of the uplink path in the remote antenna unit of the DAS. 
     
     
         22 . The TDD switching sub-system of  claim 16 , wherein the remote unit comprises a single-node repeater, wherein the at least one processor is configured to disconnect the antenna from the downlink path of the single-node repeater by switching at least one switch of the downlink path of the single-node repeater and communicatively couple the antenna to an uplink path of the single-node repeater by switching at least one switch of the uplink path of the single-node repeater. 
     
     
         23 . The TDD switching sub-system of  claim 16 , wherein the at least one processor is further configured to determine a start time of the downlink signal and update the clock setting based on the determined start time of the downlink signal.