Power measurement of received CDMA signals using soft threshold preprocessing after correlation

Abstract

A receiver for generating a soft threshold value for use in measuring the power of a received signal includes a correlator, an automatic gain controller, a noise level measuring device, and a soft threshold device. The correlator is configured to receive the signal as an input and to produce a correlated signal. The automatic gain controller is configured to receive the signal as an input and to produce a gain control value. The noise level measuring device is configured to receive the signal as an input and to produce a noise level measurement. The soft threshold device is configured to receive the gain control value and the noise level measurement as inputs and to produce a soft threshold value. The soft threshold device is further configured to apply the soft threshold value to the correlated signal and to discard any correlated signals that are below the soft threshold value.

1 . A receiver for generating a soft threshold value for use in measuring the power of a received signal, comprising: 
 a correlator, configured to receive the signal as an input and to produce a correlated signal;    an automatic gain controller, configured to receive the signal as an input and to produce a gain control value;    a noise level measuring device, configured to receive the signal as an input and to produce a noise level measurement; and    a soft threshold device, configured to receive the gain control value and the noise level measurement as inputs and to produce a soft threshold value, said soft threshold device configured to apply the soft threshold value to the correlated signal and to discard any correlated signals that are below the soft threshold value.    
     
     
         2 . The receiver according to  claim 1 , further comprising: 
 a noise level scaling device, configured to receive the correlated signal and the noise level measurement as inputs and to produce a scaled correlated signal, the scaled correlated signal being sent to said soft threshold device as an input.    
     
     
         3 . A method for generating a soft threshold value for use in measuring the power of a received signal, comprising: 
 producing a correlated signal, based on the received signal;    generating a gain control value, based on the received signal;    generating a noise level measurement, based on the received signal;    producing a soft threshold value, based on the gain control value and the noise level measurement;    applying the soft threshold value to the correlated signal; and    discarding any correlated signals that are below the soft threshold value.    
     
     
         4 . The method according to  claim 3 , further comprising: 
 generating a scaled correlated signal, based on the correlated signal and the noise level measurement, the scaled correlated signal being used in said applying.    
     
     
         5 . An integrated circuit for measuring the power of a received signal, comprising: 
 a noise level measuring device configured to measure a noise level of the received signal;    an automatic gain control device configured to determine a gain of the received signal;    a sampling device configured to sample the received signal;    a sequence generator configured to supply a reference sequence;    a sequence correlator configured to correlate the sampled signals with the reference sequence, producing correlated signals;    a soft threshold device configured to apply a soft threshold to the correlated signals; and    an accumulator configured to accumulate the correlated signals after being processed by said soft threshold device, said accumulator producing the power measurement of the received signal.    
     
     
         6 . The integrated circuit according to  claim 5 , wherein the soft threshold is derived from the gain of the received signal and the noise level of the received signal.  
     
     
         7 . The integrated circuit according to  claim 5 , further comprising: 
 a noise level scaling device configured to scale the noise level measurement obtained from said noise level measurement device; and    a noise level descaling device in communication with said soft threshold device and said accumulator, said noise level descaling device configured to descale the processed correlated signals using the noise level measurement.    
     
     
         8 . A receiver for measuring the power of a signal, comprising: 
 an antenna configured to receive a signal;    a noise level measuring device configured to measure a noise level of the received signal;    an automatic gain control device configured to determine a gain of the received signal;    a sampling device configured to sample the received signal;    a sequence generator configured to supply a reference sequence;    a sequence correlator configured to correlate the sampled signals with the reference sequence, producing correlated signals;    a soft threshold device configured to apply a soft threshold to the correlated signals; and    an accumulator configured to accumulate the correlated signals after being processed by said soft threshold device, said accumulator producing the power measurement of the received signal.    
     
     
         9 . The receiver according to  claim 8 , wherein the soft threshold is derived from the gain of the received signal and the noise level of the received signal.  
     
     
         10 . The receiver according to  claim 8 , wherein said antenna is in communication with said automatic gain control device and said noise level measuring device.  
     
     
         11 . The receiver according to  claim 8 , wherein said noise level measuring device is in communication with said soft threshold device.  
     
     
         12 . The receiver according to  claim 8 , wherein said automatic gain control device is in communication with said sampling device and said soft threshold device.  
     
     
         13 . The receiver according to  claim 8 , wherein said sampling device is in communication with said sequence correlator.  
     
     
         14 . The receiver according to  claim 8 , wherein said sequence generator is in communication with said sequence correlator.  
     
     
         15 . The receiver according to  claim 8 , wherein said sequence correlator is in communication with said soft threshold device.  
     
     
         16 . The receiver according to  claim 8 , wherein said soft threshold device is in communication with said accumulator.  
     
     
         17 . The receiver according to  claim 8 , further comprising: 
 a noise level scaling device configured to scale the noise level measurement obtained from said noise level measurement device; and    a noise level descaling device in communication with said soft threshold device and said accumulator, said noise level descaling device configured to descale the processed correlated signals using the noise level measurement.    
     
     
         18 . The receiver according to  claim 17 , wherein said noise level scaling device is in communication with said sequence correlator and said soft threshold device.