Method, access point and wtru for controlling transmission power levels of uplink/downlink communication in a wireless communication system

Abstract

Transmission power levels of uplink/downlink communication is controlled in a wireless communication system. A receiving station produces and provides to a transmitting station power control information based upon received signals from the transmitting station. A measured block error rate (BLER msr ) is obtained from the number of erroneous blocks in a sliding window of the last N received data blocks and SIR adjustments are set based upon the BLER msr and a target BLER (BLER target ). A target SIR of received signals is adjusted according to the SIR adjustments.

1 . A base station (BS) for use in a wireless communication system, the BS comprising:
 a receiver configured to receive a signal;   a demodulator configured to produce a baseband signal from a received signal;   a data estimation device configured to recover data from the baseband signal;   an error detection device configured to detect errors in the recovered data;   a processor configured to analyze the detected errors and to determine an error rate of the received communication;   a target signal to noise ratio (SIR) generator configured to generate a target SIR based on the error rate; and   a power control information generator configured to generate power control information including a step size.   
     
     
         2 . The BS of  claim 1 , wherein the error rate determined is a block error rate (BLER) of the received communication. 
     
     
         3 . The BS of  claim 1 , further comprising:
 the power control information generator configured to generate power control information based an inner loop power control setting.   
     
     
         4 . The BS of  claim 1 , further comprising:
 a memory configured to store power adjustment data; and   the processor configured to adjust the step size based on the stored power adjustment data.   
     
     
         5 . The BS of  claim 1 , further comprising:
 a forward error correction (FEC) decoder configured to perform error correction on the baseband signal.   
     
     
         6 . The BS of  claim 1 , wherein the power control information generator computes a target power control (TPC) command based on the target SIR. 
     
     
         7 . The BS of  claim 1 , further comprising:
 the processor configured to generate a new target SIR based on a cyclic redundancy check (CRC) check of the received data blocks.   
     
     
         8 . A method for power control, implemented in a base station (BS) of a wireless communication system, the method comprising:
 receiving a signal;   generating a baseband signal from the received signal;   recovering data from the baseband signal using a data estimation device;   detecting errors in the recovered data;   determining an error rate of the received communication;   generating a target SIR based on the error rate; and   generating power control information based on the target SIR.   
     
     
         9 . The method of  claim 8 , wherein the error rate determined is a BLER of the received signal. 
     
     
         10 . The method of  claim 8 , further comprising:
 detecting errors in the recovered data using a forward error correction (FEC) decoder.   
     
     
         11 . The method of  claim 8 , further comprising:
 generating the power control information based an inner loop power control setting.   
     
     
         12 . The method of  claim 8 , further comprising:
 tracking a number of errors occurring over a predetermined period of time; and   adjusting the step size based on the number of errors over the predetermined period of time.   
     
     
         13 . The method of  claim 8 , further comprising:
 measuring the SIR of a received signal;   comparing the measured SIR to the target SIR; and   transmitting a transmit power control (TPC) command requesting an increase in transmit power in the case that the measured SIR is greater than the target SIR.   
     
     
         14 . The method of  claim 8  further comprising:
 generating a new target SIR based on a cyclic redundancy check (CRC) of the received data blocks.