Patent ID: 7573860

Claim:
A method comprising: receiving a pre-defined number of status information items, said status information items each containing at least one of an acknowledgement item and a non-acknowledgement item in accordance with an automatic repeat request associated with an i-th re-transmission during an uplink data transmission between a mobile terminal device and a base station via a code division multiple access system employing said automatic repeat request, said uplink data transmission being operated in a sequence of first transmissions and i-th re-transmissions; determining a first error quantity and a second error quantity from said pre-defined number of status information items, said first error quantity being equal to a number of i-th re-transmissions, said second error quantity being equal to a number of i-th re-transmissions being responded by status information items each containing said non-acknowledgement item; determining an error ratio from said first error quantity and said second error quantity; and determining a transmission power factor from a current valid transmission power factor and a transmission power correction factor such that a difference between said error ratio and a pre-defined target error ratio is minimized, wherein said determining of the transmission power factor further comprises: determining a deviation value of said error ratio from said pre-defined target error ratio; in case said first error quantity is unequal to zero or said deviation value exceeds a pre-defined deviation level: determining said transmission power correction factor depending on at least a transmission power correction step value, said first error quantity, said second error quantity and said pre-defined target error ratio; and determining said transmission power factor; otherwise: maintaining a current valid transmission power factor being operable with said i-th re-transmission, and further wherein said transmission power correction factor is a product of a first factor, a second factor and a third factor, wherein a value of said first factor is equal to a value out of −1 and +1; said second factor is defined mathematically as following: ( C Ni Ki · FER Ki ⁡ ( 1 - FER ) Ni - Ki FER ) - 1 where C Ni Ki is a binomial coefficient, FER is said pre-defined target error ratio, Ni is said first error quantity and Ki is said second error quantity; and said third factor is said transmission power correction step value.