Abstract: A direct conversion receiver includes a receiver for receiving a signal including multiple components at different receiving frequencies belonging to a frequency band. A mixer mixes the signal components into a base band signal comprising I- and Q branches. A converter converts the analog base band signal into a digital signal. The receiver includes a measuring unit for measuring power levels of the signal components in pairs, where one component in the pair belongs to an upper sideband of the frequency band and one component in the pair belongs to a lower sideband of the frequency band. An estimator estimates, when either the upper sideband component or the lower sideband component dominates in power over the component in the pair, a frequency-independent phase imbalance, a frequency-dependent phase imbalance and a gain imbalance, and a compensator compensates the estimated imbalances to at least one of the I- and Q-branch signals.

Abstract: A direct conversion receiver includes a receiver for receiving a signal including multiple components at different receiving frequencies belonging to a frequency band. A mixer mixes the signal components into a base band signal comprising I- and Q branches. A converter converts the analog base band signal into a digital signal. The receiver includes a measuring unit for measuring power levels of the signal components in pairs, where one component in the pair belongs to an upper sideband of the frequency band and one component in the pair belongs to a lower sideband of the frequency band. An estimator estimates, when either the upper sideband component or the lower sideband component dominates in power over the component in the pair, a frequency-independent phase imbalance, a frequency-dependent phase imbalance and a gain imbalance, and a compensator compensates the estimated imbalances to at least one of the I- and Q-branch signals.

Abstract: The invention relates to a method for controlling a gain applied to signals which are transmitted by a transmitting unit via an air interface and received by a receiving unit. In order to overcome problems resulting from varying power levels of signals received by the receiving unit, it is proposed that it is determined before reception by said receiving unit for at least some of to be received signals an expected power level in said receiving unit. The determination is based on parameter values used by said transmitting unit for setting a transmission power for said at least some of said to be received signals and which are known at the receiving unit. The gain is then adjusted based on said determined expected power level. The invention equally relates to a receiving unit with corresponding means, and to a communications network and a communications system comprising such a receiving unit.

Abstract: The invention relates to a power control method and a cellular radio system used for power control, comprises at least one subscriber terminal, one base station and means for changing the step size to be used for power control. The means receive information on the speed of the subscriber terminal and the cellular radio system uses a fading channel. The means change the step size to be used for power control on the basis of the information on hte speed of the subscriber terminal for diminishing fading in the channel.