Adaptive coverage area control in an on-frequency repeater

Abstract

A system operates to adaptively control the coverage area of an on-frequency repeater. First RF signals received from a transceiver (such as a base station, or a subscriber's wireless communications device) are detected using a broadband detector, narrowband down converter and detector, and these detected signals are monitored by a micro controller. The micro controller operates, under control of suitable software implementing an Adaptive Control Algorithm, to adjust the ERP of second RF signals transmitted to the transceiver to thereby control the coverage area of the repeater, and maintain a substantially constant power level of the second RF signals received by the transceiver.

We claim:  
     
         1 . A method of adaptively controlling a coverage area of a transceiver of a wireless communications network, the method comprising steps of: 
 detecting a power level of a first RF signal received from a second transceiver of the wireless communications network; and    controlling an effective radiated power (ERP) of a second RF signal transmitted to the second transceiver, using the detected power level, so as to maintain a substantially constant power level of the second RF signal received by the second transceiver.    
     
     
         2 . A method as claimed in  claim 1 , wherein the second transceiver is either one of a base station and a subscriber's wireless communications device.  
     
     
         3 . A method as claimed in  claim 1 , wherein the step of detecting the power level of the first RF signal comprises steps of: 
 detecting the first RF signal within a wide bandwidth signal path of the transceiver; and    comparing the detected power level to the predetermined threshold.    
     
     
         4 . A method as claimed in  claim 3 , wherein the step of comparing the detected power level to the predetermined threshold comprises a step of calculating a difference between the detected power level and the predetermined threshold.  
     
     
         5 . A method as claimed in  claim 4 , wherein the predetermined threshold comprises an initial power level of the first RF signal.  
     
     
         6 . A method as claimed in  claim 4 , wherein the predetermined threshold is based on a format of the first RF signal.  
     
     
         7 . A method as claimed in  claim 6 , further comprising steps of: 
 analyzing the first RF signal to determine the format of the first RF signal; and    selecting the threshold from among a set of predetermined threshold values, based the determined format.    
     
     
         8 . A method as claimed in  claim 1 , wherein the step of controlling the effective radiated power (ERP) of the second RF signal comprises steps of: 
 estimating a variation in propagation loss between the transceivers based on the comparison result;    estimating a variation in the ERP of the second RF signal required to compensate the estimated propagation loss variation; and    adjusting the ERP of the second RF signal in accordance with the estimated ERP variation.    
     
     
         9 . A method as claimed in  claim 8 , wherein the step of adjusting the ERP of the second RF signal comprises a step of adjusting a total gain of a wide bandwidth signal path conveying the second RF signal.  
     
     
         10 . A system for adaptively controlling a coverage area of a transceiver of a wireless communications network, the system comprising: 
 a detector adapted to detect a power level of a first RF signal received from a second transceiver of the wireless communications network; and    a controller adapted to control an effective radiated power (ERP) of a second RF signal transmitted to the second transceiver, using the detected power level, so as to maintain a substantially constant power level of the second RF signal received by the second transceiver.    
     
     
         11 . A system as claimed in  claim 10 , wherein the second transceiver is any one of a base station, a repeater and a subscriber's wireless communications device.  
     
     
         12 . A system as claimed in  claim 10 , wherein the detector comprises at least a narrow-band detector adapted to detect the first RF signal within a respective first wideband signal path of the transceiver.  
     
     
         13 . A system as claimed in  claim 10 , wherein the controller comprises: 
 a processor; and    a variable gain amplifier responsive to a control signal from the processor to control the ERP of the second RF signal by adjusting gain of a respective second wideband signal path conveying the second RF signal through the transceiver.    
     
     
         14 . A system as claimed in  claim 13 , wherein the processor is adapted to compare the detected power level to a predetermined threshold.  
     
     
         15 . A system as claimed in  claim 14 , wherein the predetermined threshold comprises an initial power level of the first RF signal.  
     
     
         16 . A system as claimed in  claim 14 , wherein the predetermined threshold is based on a format of the first RF signal.  
     
     
         17 . A system as claimed in  claim 16 , wherein the processor is further adapted to: 
 analyze the first RF signal to determine the format of the first RF signal; and    select the threshold from among a set of predetermined threshold values, based the determined format.    
     
     
         18 . A system as claimed in  claim 13 , wherein the processor is further adapted to: 
 estimate a variation in propagation loss between the transceivers based on the comparison result;    estimate a variation in the ERP of the second RF signal required to compensate the estimated propagation loss variation; and    generate the control signal to control the variable gain amplifier in accordance with the estimated ERP variation.