Abstract: An apparatus and a method for beamforming with less heat in a wireless communication system including multiple antennas are provided. The apparatus includes a digital signal processor for processing at least one baseband digital signal, and at least one Radio Frequency (RF) signal processor for converting a respective baseband digital signal of the at least one baseband digital signal into an RF analog signal and for amplifying a power of the RF analog signal for one or more antenna elements constituting a respective antenna of the at least one antenna.

Abstract: An apparatus and a method for beamforming with less heat in a wireless communication system including multiple antennas are provided. The apparatus includes a digital signal processor for processing at least one baseband digital signal, and at least one Radio Frequency (RF) signal processor for converting a respective baseband digital signal of the at least one baseband digital signal into an RF analog signal and for amplifying a power of the RF analog signal for one or more antenna elements constituting a respective antenna of the at least one antenna.

Abstract: Provided is a TRAS in a TDD wireless communication system. In the TRAS, a circulator transmits a signal received from a PA to an antenna feed line and a signal received from the antenna feed line to a reflector. The reflector fully reflects the signal received from the circulator when a reflection operation is turned on in transmission mode, and transmits the signal received from the circulator to a wireless switch, such as, an RF switch when the reflection operation is turned off in reception mode. The RF switch transmits or blocks the signal received from the reflector to or from an LNA according to the transmission or reception mode.

Abstract: An RF front-end apparatus in a TDD wireless communication system is provided. In the RF front-end apparatus, a detector is provided at a predetermined position in a signal path, and detects a signal propagating in the signal path. A circulator provides a signal received from a power amplifier to an antenna feed line and a signal received from the antenna feed line to a switch. A switch controller generates a control signal based on the signal received from the detector and a switch on/off signal received from a control board. The switch, which is disposed at an input port of an LNA, switches on/off according to the control signal received from the switch controller.

Abstract: A transmitting apparatus in a TDD wireless communication system is provided. In the transmitting apparatus, a circulator transmits a signal received from a power amplifier to an antenna feed line and transmits a signal received from the antenna feed line to a quarter-wave transmission line. The quarter-wave transmission line is installed in a reception path, for reception isolation in a transmission mode. An RF switch shorts the load of the quarter-wave transmission line to the ground or connects the load of the quarter-wave transmission line to an LNA according to a control signal. The LNA low-noise-amplifies a signal received from the RF switch.

Abstract: In a circuit for controlling an RF output voltage level and identifying the continuity of an IFL cable using a low frequency signal, the low frequency signal is transmitted to an outdoor unit after being level-controlled in an indoor unit. The level of an intermediate frequency transmission (IF TX) signal input to a transmit block up-converter (TBU) is controlled using the low frequency signal so that the RF output voltage level output from a solid state power amplifier (SSPA) is finally controlled. The low frequency signal is transmitted back from the outdoor unit to the indoor unit, and the indoor equipment detects the signal, thereby identifying the presence or absence of an abnormal connection of an IFL cable. An EIRP adjustment circuit is simplified without a microcomputer and its pheripheral circuits, by using a low-frequency signal which is not damaged by a communication cable. Also, the attenuation of the IF TX signal due to the communication cable is automatically compensated.

Abstract: A wireless common printer system capable of achieving a print operation in accordance with a priority sequence by, at the side of personal computers, differentially encoding data to be printed by use of pseudo noise codes allocated to the computers like intrinsic identifiers and transmitting the data after spreading it in a direct sequence and, at the side of printer, extracting data from those received from the computers by use of a despread spectrum technique utilizing matched filters having individual intrinsic identifier codes. Since the common printer system is the wireless system eliminating requirements of a separate printer switching unit and a printer cable, there is no limitation on the usable distance in so far as electric power of a certain radio frequency is kept. By virtue of this feature, the common printer system provide an enhanced convenience when it is applied to lap top computers and personal note book computers having a high movability.