A method for updating of the reference value in a closed loop high speed on the basis of probability

摘要

PROBLEM TO BE SOLVED: To follow a fluctuation in a communication channel by reducing an update period of a reference value in closed loop transmission power control. ;SOLUTION: In the case of discriminating a path providing the least accumulated value of a humming distance from a received series as a decode series among paths on a trellis diagram in the Viterbi algorithm, a likelihood that is an accumulated value of the humming distance between the decode series and the received series for a prescribed period is detected (step 102). In the case that the likelihood is a threshold value A or below, a reference Eb/I0 is increasingly updated immediately (step 105). In the case that the likelihood is higher than the threshold value A, a mean value of the likelihood values for N times is obtained (step 108), an when the mean value is smaller than L, the reference value is increased (step 110), and when the mean value is larger than M, the reference value is decreased (step 113), and in the other cases, the reference value is not updated (step 112).;COPYRIGHT: (C)2000,JPO