APPARATUS AND METHOD FOR COOPERATIVE TRANSMISSION IN MULTIPLE ANTENNA SYSTEM

摘要

An apparatus and a method for relaying signals for cooperative transmission in a multiple antenna system are provided to make it unnecessary for a terminal to know definite downlink CSI(Channel State Information) and to simplify a structure of a receiving unit in the terminal. An apparatus for relaying signals for cooperative transmission includes a detector(301), a demodulator(303), a decoder(305), a controller(307), a channel estimator(309), a channel gain comparator(311), an encoder(313), a modulator(315), a multiplexor(317), a reference data generator(319) and a power restricting unit(321). The detector detects a sounding signal or a pilot signal from multiple antennas of the terminal, and outputs the detected signal to the channel estimator. The demodulator demodulates the signal, outputted by the detector, according to a modulation scheme of a transmitter and outputs coded data. The decoder receives the coded data from the demodulator, decodes the coded data into original data, and outputs the original data to the controller. The channel estimator estimates channels among the multiple antennas by using the detected sounding signal or pilot signal, and provides the estimated channel value for the channel gain comparator and the multiplexor. The channel gain comparator calculates a channel gain by referring to the provided estimated channel value, compares the calculated channel gain with a threshold, and determines whether a cooperative communication is performed together with the terminal. The controller reports the calculated channel gain to a base station in case that the cooperative communication has to be performed. The power restricting unit calculates a power restriction constant by using the estimated channel value, and provides the power restriction constant for the multiplexor.