Antennas Array Calibration Arrangement and Method
A compressor comprising a hermetical container, a compression mechanism disposed in a lower portion in the hermetical container, a rotational motor disposed in an upper portion in the hermetical container and having a stator and a rotor, coil ends provided on upper end lower ends of the stator, a discharge pipe provided on an upper end of the hermetical container, and an oil reservoir provided in a lower portion in the hermetical container, in which working fluid compressed by the compression mechanism is introduced into an upper space of the hermetical container from a gap between the rotational motor and the hermetical container, and the working fluid is discharged out from the hermetical container through the discharge pipe, wherein an open end in the hermetical container of the discharge pipe is located inside the upper end coil end.
1 - 13 . (canceled)
14 . A system for controlling at least one of transmission and reception of signals in a radio communication system having a calibration antenna and an array of antenna elements, comprising:
a plurality of transceiving means, each connected to one element of the array of antenna elements, at least one of said transceiving means additionally connected to the calibration antenna, for at least one of transmitting and receiving test signals via the antenna elements;
at least one calibration processor determining variations of the test signals in said transceiving means; and
a beamforming processor taking into account the variations determined by said calibration processor for at least one of beamforming and determination of direction of arrival of radio signals respectively transmitted and received by the antenna elements.
15 . A system according to claim 14 , wherein a transmission gap in a time frame of a time division duplex system is used for transmission of the test signals for determining variations in said calibration processor.
16 . A system according to claim 15 , wherein in said at least one transceiving means connected to the calibration antenna test signals are switched via a switch to the calibration antenna in a calibration process.
17 . A system according to claim 16 , wherein said calibration processor is realized within said beamforming processor.
18 . A system according to claim 17 , further comprising at least one lookup table storing information related to the variations of the test signals.
19 . A system according to claim 18 ,
further comprising a base band multiplexer connected to said transceiving means, and
wherein said at least one calibration processor includes at least two calibration processors, each determining variations for a different radio frequency, connected to said transceiving means via said base band multiplexer.
20 . A system according to claim 14 , further comprising a base station of the radio communication system, in which said transceiving means, said at least one calibration processor and said beamforming processor are located.
21 . A method for controlling at least one of transmission and reception of signals in a radio communication apparatus having transceivers, each connected to one element of an array of antenna elements, at least one of the transceivers being additionally connected to a calibration antenna, said method comprising:
at least one of a receiver calibration procedure and a transmitter calibration procedure, the receiver calibration procedure including:
generating test signals,
feeding the test signals to the at least one of the transceivers connected to the calibration antenna,
transmitting the test signals via the calibration antenna,
receiving the test signals by the antenna elements and corresponding transceivers,
determining, in at least one calibration processor, reception variations of the test signals in the transceivers, and
taking into account the reception variations, determined in the at least one calibration processor, for determination of direction of arrival of respectively received radio signals by the antenna elements; and
the transmitter calibration procedure, including
generating the test signals,
feeding the test signals to the transceivers,
transmitting the test signals via the antenna elements,
receiving the test signals by the calibration antenna and the at least one of the transceivers connected thereto,
determining, in the at least one calibration processor, transmission variations of the test signals in the transceivers, and
taking into account the transmission variations, determined in the at least one calibration processor, for beamforming of respectively transmitted radio signals from the antenna elements.
22 . A method according to claim 21 , wherein at least one of the reception and transmission variations of the test signals are determined consecutively for different radio frequencies.
23 . A method according to claim 22 , wherein at least one of the reception and transmission variations of the test signals are determined concurrently for different radio frequencies, using individual calibration processors for the different radio frequencies.
24 . A method according to claim 23 , further comprising determining transfer functions of at least one of transmitting and receiving paths in the calibration processor.
25 . A method according to claim 24 , further comprising determining a maximum of a phase and amplitude difference of a coupling coefficient in each calibration processor.
26 . (canceled)
27 . A method according to claim 21 , wherein said transmitting of the test signals via the calibration antenna and the antenna elements in the receiver and transmitter calibration procedures, respectively, occurs in a transmission gap in a time frame of a time division duplex system.