Method and arrangement for forming a beam

A method for forming a beam of a signal to be transmitted from at least one transceiver in a TDD communication system, the method comprising:

• a base station receiving and transmitting by using an antenna comprising at least two elements;
• the base station calculating an estimate of received interference power;
• the base station transmitting a signal comprising information on the transmit power and the interference power at the base station;
• a subscriber equipment receiving the signal, forming a channel estimate and calculating the power of a signal to be transmitted to the base station on the basis of the information in the received signal and the channel estimate of the received signal;
• the subscriber equipment transmitting to the base station by using the estimated transmit power;
• the base station receiving the signal transmitted by the subscriber equipment and the base station calculating beam forming coefficients for each antenna element on the basis of the received signal by
• estimating responses of the antenna of the received signal at different delays;
• selecting a subset of at least one response of the antenna at such a delay or delays that the selected at least one response of the antenna has a local energy maximum;
• calculating the beam forming coefficients by using the selected subset;
• and
• multiplying the signal to be transmitted by the beam forming coefficients for each antenna element.

A method for forming a beam of a signal to be transmitted from at least one transceiver in a TDD communication system in conjunction with a call set-up, the method comprising:

• a base station receiving and transmitting by using an antenna comprising at least two elements;
• the base station calculating an estimate of received interference power;
• the base station transmitting a common downlink signal comprising information on the transmit power and the interference power at the base station;
• a subscriber equipment receiving the common downlink signal, forming a channel estimate and calculating the power of an access signal to be transmitted to the base station on the basis of the information in the received common downlink signal and the channel estimate of the received common downlink signal;
• the subscriber equipment transmitting the access signal to the base station by using the estimated transmit power;
• the base station receiving the access signal transmitted by the subscriber equipment and the base station calculating beam forming coefficients for each antenna element on the basis of the received access signal by
• estimating responses of the antenna at different delays for the subscriber equipment;
• selecting a subset of at least one response of the antenna at such a delay or delays that the selected at least one response of the antenna has a local energy maximum;
• calculating the beam forming coefficients for each different transceiver by using the selected subset;
• and
• multiplying the signal to be transmitted by the beam forming coefficients.

An arrangement for forming a beam of a signal to be transmitted from at least one transceiver in a TDD communication system that comprises at least one base station and at least one subscriber equipment which are transceivers,

• a transceiver comprising an antenna with at least two elements for receiving and transmitting a signal;
• the transceiver being arranged to receive a multipath propagated signal from at least one different transceiver and to estimate responses of the antenna at different delays for each different transceiver;
• the transceiver being arranged to select a subset of at least one response of the antenna for at least one different transceiver at such a delay or delays that the selected at least one response of the antenna has a local energy maximum;
• the transceiver being arranged to calculate beam forming coefficients for each different transceiver by using the selected subset;
• and
• the transceiver being arranged to multiply the signal to be transmitted by the beam forming coefficients for each antenna element.

An arrangement for forming a beam of a signal to be transmitted from at least one transceiver in a TDD communication system that comprises at least one base station and at least one subscriber equipment which are transceivers,

• a base station comprising an antenna with at least two elements for receiving and transmitting signals;
• the base station being arranged to calculate an estimate of received interference power;
• the base station being arranged to transmit a signal comprising information on the transmit power and the interference power at the base station;
• a subscriber equipment being arranged to receive the signal, to form a channel estimate and to calculate the power of a signal to be transmitted to the base station on the basis of the information in the received signal and the channel estimate of the received signal;
• the subscriber equipment being arranged to transmit to the base station by using the estimated transmit power;
• the base station being arranged to receive the signal transmitted by the subscriber equipment and the base station being arranged to calculate the beam forming coefficients for each antenna element on the basis of the received signal so that
• the base station is arranged to estimate responses of the antenna of the received signal at different delays;
• the base station is arranged to select a subset of at least one response of the antenna at such a delay or delays that the selected at least one response of the antenna has a local energy maximum;
• the base station is arranged to calculate the beam forming coefficients by using the selected subset;
• and
• the base station is arranged to multiply the signal to be transmitted by the beam forming coefficients for each antenna element.

An arrangement for forming a beam of a signal to be transmitted from at least one transceiver during a call set-up in a TDD communication system that comprises at least one base station and at least one subscriber equipment which are transceivers,

• a base station comprising an antenna with at least two elements for receiving and transmitting;
• the base station being arranged to calculate an estimate of received interference power;
• the base station being arranged to transmit a common downlink signal comprising information on the transmit power and the interference power at the base station;
• a subscriber equipment being arranged to receive the common downlink signal, to form a channel estimate and to calculate the power of an access signal to be transmitted to the base station on the basis of the information in the received common downlink signal and the channel estimate of the received common downlink signal;
• the subscriber equipment being arranged to transmit the access signal to the base station by using the estimated transmit power;
• the base station being arranged to receive the access signal transmitted by the subscriber equipment and the base station being arranged to calculate beam forming coefficients for each antenna element on the basis of the received access signal so that
• the base station is arranged to estimate responses of the antenna of the received signal at different delays;
• the base station is arranged to select a subset of at least one response of the antenna at such a delay or delays that the selected at least one response of the antenna has a local energy maximum;
• the base station is arranged to calculate the beam forming coefficients by using the selected subset;
• and
• the base station is arranged to multiply the signal to be transmitted by the beam forming coefficients for each antenna element.

A method for forming a beam of a signal to be transmitted from at least one transceiver in a TDD communication system, the method comprising:

• receiving and transmitting, by a subscriber equipment, a signal using an antenna comprising at least two elements;
• receiving, by the subscriber equipment, a multipath propagated signal from at least one base station and estimating, by the subscriber equipment, responses of the antenna at different delays for each base station;
• selecting, by the subscriber equipment, a subset of at least one response of the antenna for at least one base station at such a delay or delays that the selected at least one response of the antenna has a local energy maximum;
• calculating, by the subscriber equipment, beam forming coefficients using the selected subset;
• and
• multiplying, by the subscriber equipment, the signal to be transmitted by the beam forming coefficients for each antenna element.

An arrangement for forming a beam of a signal to be transmitted from at least one transceiver in a TDD communication system that comprises at least one base station and at least one subscriber equipment which are transceivers,

• the subscriber equipment comprising an antenna with at least two elements for receiving and transmitting a signal;
• the subscriber equipment being arranged to receive a multipath propagated signal from at least one base station and to estimate responses of the antenna at different delays for each base station;
• the subscriber equipment being arranged to select a subset of at least one response of the antenna for at least one base station at such a delay or delays that the selected at least one response of the antenna has a local energy maximum;
• the subscriber equipment being arranged to calculate beam forming coefficients using the selected subset;
• and
• the subscriber equipment being arranged to multiply the signal to be transmitted by the beam forming coefficients for each antenna element.