Base station using global channel power control

Abstract

A wireless spread spectrum base station has a plurality of modems. The modems produce at least one baseband channel signal and a baseband reference signal. At least one forward power controller controls a power level of the at least one baseband channel signal. A baseband signal combiner combines the at least one baseband channel and baseband reference signals. A radio frequency transmitter modulates to radio frequency and transmits the combined signal. A reference power control processor determines a desired transmit power level of the baseband reference signal to the desired transmit power level.

1 . In a cellular wireless communication system including a plurality of base stations and wireless transmit/receive units (WTRUs) wherein each base station transmits a reference signal over an entire range of a cell, a method for controlling transmit power of the reference signal, the method comprising: 
 a base station measuring a total transmit power level of combined signals on a channel specifically assigned to a WTRU and a reference signal; and    the base station adjusting a transmit power level of the reference signal based on the total transmit power level of the combined signals.    
   
   
       2 . The method of  claim 1 , wherein the total transmit power level is measured after combining signals on a channel specifically assigned to a WTRU and the reference signal.  
   
   
       3 . The method of  claim 1 , wherein individual transmit power levels are measured at each assigned channel and a reference channel, and the total transmit power level is measured by summing the individual transmit power levels.  
   
   
       4 . The method of  claim 1 , wherein the total transmit power level is measured after transmission of combined signals on a channel specifically assigned to a WTRU and the reference signal.  
   
   
       5 . The method of  claim 1 , wherein the transmit power level of the reference signal is determined based on at least one of: a desired signal-to-noise ratio (SNR), a processing gain, a transmit bandwidth, a noise density, a cell radius, and a carrier frequency.  
   
   
       6 . The method of  claim 1 , wherein the transmit power level of the reference signal is determined using at least one of: a free space propagation model, a Hata model, and a break-point model.  
   
   
       7 . The method of  claim 1 , wherein the transmit power level of the reference signal is adjusted continuously.  
   
   
       8 . The method of  claim 1 , wherein the transmit power level of the reference signal is adjusted on a periodic basis.  
   
   
       9 . In a cellular wireless communication system including a plurality of base stations and wireless transmit/receive units (WTRUs) wherein each base station transmits a reference signal over an entire range of a cell, an apparatus for controlling transmit power of the reference signal, the apparatus comprising: 
 a transmit power measurement unit configured to measure a total transmit power level of combined signals on a channel specifically assigned to a WTRU and a reference signal; and    a reference channel power control processor configured to adjust a transmit power level of the reference signal based on the total transmit power level of the combined signals.    
   
   
       10 . The apparatus of  claim 9 , wherein the transmit power measurement unit is configured to measure the total transmit power level after combining signals.  
   
   
       11 . The apparatus of  claim 9 , wherein the transmit power measurement unit is configured to: 
 measure individual transmit power levels at each assigned channel and a reference channel; and    sum the individual transmit power levels to calculate the total transmit power level.    
   
   
       12 . The apparatus of  claim 9 , wherein the transmit power measurement unit is configured to measure the total transmit power level after transmission of the combined signals.  
   
   
       13 . The apparatus of  claim 9 , wherein the reference channel power control processor is configured to determine the transmit power level of the reference signal based on at least one of: a desired signal-to-noise ratio (SNR), a processing gain, a transmit bandwidth, a noise density, a cell radius, and a carrier frequency.  
   
   
       14 . The apparatus of  claim 9 , wherein the reference channel power control processor is configured to determine the transmit power level of the reference signal using at least one of: a free space propagation model, a Hata model, and a break-point model.  
   
   
       15 . The apparatus of  claim 9 , wherein the reference channel power control processor is configured to adjust the transmit power level of the reference signal continuously.  
   
   
       16 . The apparatus of  claim 9 , wherein the reference channel power control processor is configured to adjust the transmit power level of the reference signal on a periodic basis.