Power Level of Transmitted Control Channel Symbol

Abstract

Channel estimation accuracy is improved by adjusting the power level of a physical control channel allocated to a receiver based on the transmission rate and/or transport format of a corresponding physical data channel allocated to the same receiver. The physical control channel may be a DPCCH, E-DPCCH or other type of physical control channel allocated to a receiver for facilitating uplink or downlink communication. In one embodiment, control channel symbols are transmitted for use in channel estimation by adjusting the power level of a physical control channel allocated to a receiver based on the transmission rate and/or transport format of a physical data channel allocated to the receiver ( 200 ). Control channel symbols are transmitted to the receiver over the physical control channel at the adjusted power level ( 202 ). The receiver uses the control channel symbols to perform channel estimation ( 204 ).

What is claimed is: 
     
         1 . A method of transmitting symbols used for channel estimation, comprising:
 adjusting the power level of an enhanced dedicated physical control channel allocated to a receiver based on at least one of a transmission rate and a transport format of a physical data channel allocated to the receiver; and   transmitting control channel symbols to the receiver over the enhanced dedicated physical control channel at the adjusted power level for use by the receiver in performing channel estimation.   
     
     
         2 . The method of  claim 1 , wherein the physical data channel is an enhanced dedicated physical data channel. 
     
     
         3 . The method of  claim 1 , wherein adjusting the power level of the enhanced dedicated physical control channel comprises linearly adjusting the power level of the enhanced dedicated physical control channel based on the transmission rate and/or transport format of the physical data channel. 
     
     
         4 . The method of  claim 1 , wherein adjusting the power level of the enhanced dedicated physical control channel comprises adjusting the power level of the enhanced dedicated physical control channel based on a modulation scheme of the physical data channel. 
     
     
         5 . The method of  claim 4 , wherein adjusting the power level of the enhanced dedicated physical control channel based on the modulation scheme of the physical data channel comprises stepwise adjusting the power level of the enhanced dedicated physical control channel responsive to a change in the modulation scheme of the physical data channel. 
     
     
         6 . The method of  claim 1 , wherein adjusting the power level of the enhanced dedicated physical control channel comprises adjusting the power level of the enhanced dedicated physical control channel based on a transport block size of the physical data channel. 
     
     
         7 . The method of  claim 1 , wherein adjusting the power level of the enhanced dedicated physical control channel comprises:
 increasing the power level of the enhanced dedicated physical control channel responsive to an increase in the transmission rate of the physical data channel; and   decreasing the power level of the enhanced dedicated physical control channel responsive to a decrease in the transmission rate of the physical data channel.   
     
     
         8 . The method of  claim 1 , wherein transmitting the control channel symbols to the receiver over the enhanced dedicated physical control channel at the adjusted power level comprises transmitting the control channel symbols to the receiver over an uplink enhanced dedicated physical control channel at the adjusted power level. 
     
     
         9 . A transmitter comprising a baseband processor configured to:
 adjust the power level of an enhanced dedicated physical control channel allocated to a receiver based on at least one of a transmission rate and a transport format of a physical data channel allocated to the receiver; and   transmit control channel symbols to the receiver over the enhanced dedicated physical control channel at the adjusted power level for use by the receiver in performing channel estimation.   
     
     
         10 . The transmitter of  claim 9 , wherein the physical data channel is an enhanced dedicated physical data channel. 
     
     
         11 . The transmitter of  claim 9 , wherein the baseband processor is configured to linearly adjust the power level of the enhanced dedicated physical control channel based on at least one of the transmission rate and the transport format of the physical data channel. 
     
     
         12 . The transmitter of  claim 9 , wherein the baseband processor is configured to adjust the power level of the enhanced dedicated physical control channel based on a modulation scheme of the physical data channel. 
     
     
         13 . The transmitter of  claim 12 , wherein the baseband processor is configured to stepwise adjust the power level of the enhanced dedicated physical control channel responsive to a change in the modulation scheme of the physical data channel. 
     
     
         14 . The transmitter of  claim 9 , wherein the baseband processor is configured to adjust the power level of the enhanced dedicated physical control channel based on a transport block size of the physical data channel. 
     
     
         15 . The transmitter of  claim 9 , wherein the baseband processor is configured to:
 increase the power level of the enhanced dedicated physical control channel responsive to an increase in the transmission rate of the physical data channel; and   decrease the power level of the enhanced dedicated physical control channel responsive to a decrease in the transmission rate of the physical data channel.   
     
     
         16 . The transmitter of  claim 9 , wherein the baseband processor is configured to transmit the control channel symbols to the receiver over an uplink enhanced dedicated physical control channel at the adjusted power level. 
     
     
         17 . A receiver comprising a baseband processor configured to:
 detect control channel symbols received from an enhanced dedicated physical control channel allocated to the receiver at a power level corresponding to at least one of a transmission rate and a transport format of a physical data channel allocated to the receiver; and   perform channel estimation based at least in part on the detected control channel symbols.   
     
     
         18 . The receiver of  claim 17 , wherein the physical data channel is an enhanced dedicated physical data channel. 
     
     
         19 . The receiver of  claim 17 , wherein the baseband processor is configured to detect control channel symbols received from an uplink enhanced dedicated physical control channel. 
     
     
         20 . A method of performing channel estimation at a receiver, comprising:
 detecting control channel symbols received from an enhanced dedicated physical control channel allocated to the receiver at a power level corresponding to at least one of a transmission rate and a transport format of a physical data channel allocated to the receiver; and   performing channel estimation based at least in part on the detected control channel symbols.   
     
     
         21 . The method of  claim 20 , wherein the physical data channel is an enhanced dedicated physical data channel.