Closed-loop transmitting antenna diversity method, base station apparatus and mobile station apparatus therefor, in a next generation mobile telecommunications system

A closed-loop transmitting antenna diversity method when two antennas are used in a mobile telecommunications system, the closed-loop transmitting antenna diversity method comprising the steps of:

• (a) obtaining, in a mobile station, the sign of the changed amount per unit time of the phase difference between antennas for the two antennas used in a base station;
• (b) transmitting the sign obtained in step (a) as feedback information for adjusting transmitting antenna diversity;
• (c) receiving and interpreting feedback information in the base station;
• (d) calculating the weighted value of array antennas for each antenna, using the interpreted feedback information;
• and
• (e) multiplying data, which is to be transmitted from the base station to a mobile station, by the array antenna weighted value, and outputting the result through a corresponding antenna,
• wherein the changed amount per unit time of the phase difference between antennas is obtained by subtracting the previous phase difference between antennas, which the base station knows, from the phase difference between antennas, which is calculated by a current mobile station.

A closed-loop transmitting antenna diversity method when a plurality of antennas are used in a wireless telecommunications system, the closed-loop transmitting antenna diversity method comprising the steps of:

• (a) measuring, in a receiving station, the changed amount per unit time of the phase difference between antennas for a plurality of antennas used in a transmitting station;
• (b) transmitting to the transmitting station the results of measuring in step (a) as feedback information for adjusting transmitting antenna diversity;
• (c) receiving and interpreting in the transmitting station feedback information;
• (d) calculating the weighted value of array antennas for each antenna, using the interpreted feedback information;
• and
• (e) multiplying data, which is to be transmitted from the transmitting station to the receiving station, by the array antenna weighted value, and outputting the result through a corresponding antenna,
• wherein the changed amount per unit time of the phase difference between antennas is obtained by subtracting the previous phase difference between antennas, which the transmitting station knows, from the phase difference between antennas, which is calculated by a current receiving station.

A base station apparatus for implementing closed-loop transmitting antenna diversity, when two antennas are used in a mobile telecommunications system, the base station comprising:

• first and second antennas, one or both of which receives feedback information generated from any i-th mobile station;
• a feedback information decoder for interpreting the received feedback information and detecting the changed amount per unit time of the phase difference between antennas;
• a weighted value calculating unit for calculating the weighted value of the second antenna, using the changed amount per unit time;
• and
• a transmitting unit for transmitting a data signal and a pilot signal to the mobile station through the first antenna, and transmitting the result of multiplication through the second antenna, after multiplying the data signal by the array antenna weighted value,
• wherein the changed amount per unit time of the phase difference between antennas is a value obtained by adding the changed amount per unit time of the phase difference between antennas, which is measured as feedback information in the mobile station, to a feedback error due to uplink channel noise.

A mobile station apparatus for implementing closed-loop transmitting antenna diversity when two antennas are used in a base station, the mobile station apparatus comprising:

• a plurality of fingers 1 through L for conjugating each of L multipath channels, from a first multipath channel through an L-th multipath channel, of a base antenna among two antennas, and receiving each multipath pilot symbol, from a first multipath pilot symbol to an L-th multipath pilot symbol, from the base antenna;
• a plurality of multipliers from 1 through L for multiplying the conjugated value by each corresponding pilot symbol;
• an adder for adding the outputs of the plurality of multipliers 1 through L;
• an imaginary number selecting unit for selecting the imaginary part of a complex number signal which is the output from the adder;
• and
• a determining unit for determining the sign of the selected imaginary part, and outputting a signal indicating a positive value or a negative value as feedback information.