Method and apparatus for transceiving for beam forming in wireless communication system

An electronic device for beamforming and a method thereof in a wireless communication system are provided. The electronic device includes a plurality of antennas. The electronic device also includes a plurality of transmitter and receiver switches connected to the antennas and configured to select a plurality of transmission paths and a plurality of reception paths. The electronic device further includes a plurality of first Phase Shifters (P/Ss) configured to shift a phase of Radio Frequency (RF) signals received via the antennas and the transmitter and receiver switches. The electronic device includes a combiner configured to combine the phase-shifted RF signals to one RF signal. The electronic device also includes a quadrature signal generator configured to generate a quadrature signal. The electronic device further includes a down-mixer configured to convert the quadrature signal and the combined RF signal to a first baseband signal and configured to output the first baseband signal to a modem. The electronic device includes a controller configured to control the transmitter and receiver switches, the first P/Ss, and a plurality of second P/Ss to determine a transmission or reception mode of the transmitter and receiver switches, and the phase of the RF signals transmitted and received.

The present application is related to and claims the benefit under 35 U.S.C. §119(a) to a Korean patent application filed in the Korean Intellectual Property Office on Jan. 6, 2014, and assigned Serial No. 10-2014-0001517, the entire disclosure of which is hereby incorporated by reference.

TECHNICAL FIELD

The present disclosure relates generally to a method and an apparatus for beamforming in wireless communication using a millimeter band.

BACKGROUND

In a millimeter frequency band, communications are interrupted by an obstacle due to linear propagation. Accordingly, beamforming is required to maintain a Light-of-Sight (LOS) environment and to accomplish smooth communication even in a non-LOS environment.

A transceiver for the beamforming typically employs a heterodyne structure, and includes a Radio Frequency (RF) stage, a Local Oscillator (LO) stage, and an Intermediate Frequency (IF) stage. The transceiver is divided into a transmitter and a receiver, and its antenna is also divided into a transmitting antenna and a receiving antenna.

However, such a structure increases a chip size and power consumption by the number of blocks of the IF stage.

Since the transmitter and the receiver are separated, the LO stage requires the transmitter and the receiver respectively, thus increasing the chip size and the power consumption. Further, since the transmitting antenna and the receiving antenna are separated, a certain number of antennas are required for the transmission and the reception and thus an RF packet size increases.

SUMMARY

To address the above-discussed deficiencies of the prior art, it is a primary aspect of the present invention to provide transceiving method and apparatus for beamforming in a wireless communication system.

Another aspect of the present invention is to provide a method and an apparatus for reducing a chip size and power consumption by minimizing the number of blocks of an RF transceiver using a direct conversion structure which does not use an IF stage for beamforming, and reducing a package size by use of a switch for selecting a transmitter and a receiver to employ antennas and RF chains in the same number, in a wireless communication system.

Yet another aspect of the present invention is to provide a method and an apparatus for minimizing hardware complexity by combining a transmitter and a receiver for beamforming in a wireless communication system.

According to one aspect of the present invention, an electronic device for beamforming in a wireless communication system is provided. The electronic device includes a plurality of antennas. The electronic device also includes a plurality of transmitter and receiver switches connected to the antennas and configured to select a plurality of transmission paths and a plurality of reception paths. The electronic device further includes a plurality of first Phase Shifters (P/Ss) configured to shift a phase of Radio Frequency (RF) signals received via the antennas and the transmitter and receiver switches; a combiner for combining the phase-shifted RF signals to one RF signal. The electronic device includes a quadrature signal generator configured to generate a quadrature signal. The electronic device also includes a down-mixer configured to convert the quadrature signal and the combined RF signal to a first baseband signal and configured to output the first baseband signal to a modem. The electronic device further includes a controller configured to control the transmitter and receiver switches, the first P/Ss, and a plurality of second P/Ss to determine a transmission or reception mode of the transmitter and receiver switches, and the phase of the RF signals transmitted and received.

According to another aspect of the present invention, an operating method of an electronic device for beamforming in a wireless communication system is provided. The method includes receiving a plurality of Radio Frequency (RF) signals from a plurality of antennas; selecting, at a plurality of transmitter and receiver switches, a plurality of reception paths for the received RF signals. The method also includes low-noise amplifying, at least one Low Noise Amplifier (LNA) and the received RF signals. The method further includes shifting, at first Phase Shifters (P/Ss), a phase of the RF signals low-noise amplified. The method includes combining, at a combiner, the phase-shifted RF signals. The method also includes generating, a quadrature signal generator, a quadrature signal. The method further includes down-mixing, at a down mixer, the combined RF signals and the quadrature signal to a first baseband signal and outputting the first baseband signal to a modem.

DETAILED DESCRIPTION

FIGS. 1 through 14, discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged electronic device. The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

Exemplary embodiments of the present disclosure provide transceiving method and apparatus for beamforming in a wireless communication system.

The present disclosure provides a technique for wirelessly communicating mass data over several gigabit per second (Gbps) using a millimeter band. In the millimeter band, communications are interrupted by an obstacle due to linear propagation. Accordingly, beamforming is required to maintain a Light-of-Sight (LOS) environment and to accomplish smooth communication in a non-LOS environment. In this regard, the present disclosure provides a method and an apparatus for beamforming with low hardware complexity.

FIG. 1depicts an example Radio Frequency (RF) transceiver according to this disclosure. Referring toFIG. 1, an RF beamforming transceiver100employs a direct conversion structure which converts an RF signal directly to a baseband signal, or converts a baseband signal directly to an RF signal using a single frequency converter. Herein, the direct conversion is performed by an I/Q D-mixer104-1and an I/Q U-mixer104-2. The RF beamforming transceiver100drives a transmitter and a receiver using a Quadrature Signal Generator (QSG)105including a frequency synthesizer.

The RF beamforming transceiver100is a multi-chain RF beamforming transceiver which combines or divides multi-chain RF signals using an N-way combiner101and an N-way divider102, and uses Phase Shifters (P/Ss)110-1through110-N and111-1through111-N. The RF beamforming transceiver100functions as follows. A baseband signal output from a modem107is up-mixed with a quadrature local signal of the QSG105in the I/Q U-mixer104-2and converted to an RF signal. The converted RF signal is divided into N-ary RF signals in the N-way divider102.

Next, the RF signals are radiated into the air via the P/Ss110-1through110-N, Power Amplifiers (PAs)113-1through113-N, switches114-1through114-N for selecting the transmitter and the receiver, and antennas. The RF beamforming receiver operates as follows. The RF signals received via antennas are combined to one signal through the N-way combiner101via the switches114-1through114-N for selecting the transmitter and the receiver, Low Noise Amplifiers (LNAs)112-1through112-N, and the P/Ss111-1through111-N. The combined signal is down-mixed with an output signal of the QSG105in the UQ D-mixer104-1, converted to the baseband signal, and fed to the modem107. Herein, the N-way combiner101and the N-way divider102is implemented in various fashions. For example, to combine 16 RF signals to one RF signal, 16 chains include eight 2-way combiners, two 4-way combiners, and one 2-way combiners, or include four 4-way combiners and one 4-way combiner.

For example, 16 chains include two 8-way combiners and one 2-way combiner, or include one 16-way combiner. Like the N-way combiner, the N-way divider is implemented in various structures. The QSG105is a circuit for generating a quadrature signal of a LO frequency fLOand is implemented in various fashions. For example, the QSG105includes a synthesizer for generating a signal at the frequency fLO/M, an M-fold frequency multiplier, and a 90-degree P/S, or includes a synthesizer for generating a signal at a frequency (M*fLO), an M-fold frequency divider, and a 90-degree P/S. For example, the QSG105includes a synthesizer with a Quadrature Voltage Controlled Oscillator (QVCO).

The switches114-1through114-N for selecting the transmitter and the receiver is omitted when there is no packet size issue with the small number of RF chains, or is divided to N-ary transmitting antennas and N-ary receiving antennas. The switches114-1through114-N for selecting the transmitter and the receiver set a transmission mode or a reception mode of the beamforming RF transceiver100under control of an RF controller106. The switches114-1through114-N for selecting the transmitter and the receiver select a plurality of transmitters and a plurality of receivers under the control of the RF controller106.

When a single P/S is use in both of a transmission path and a reception path, the N-way combiner and the N-way divider employ an N-way bidirectional circuit which allows bidirectional signal transfer. The RF controller106generates a control signal for setting the transmission mode or the reception mode of the switches114-1through114-N for selecting the transmitter and the receiver. The RF controller106controls phase shifting and shift level of the transceived signals by sending the control signal to the P/Ss110-1through110-N and111-1through111-N. The RF controller106receives from a main controller108a signal for controlling the switches114-1through114-N for selecting the transmitter and the receiver and the P/Ss110-1through110-N and111-1through111-N.

The modem107converts the baseband band to a bitstream and vice versa according to a physical layer standard of the system. For example, to transmit data, the modem107generates complex symbols by encoding and modulating the transmit bitstream. With the receive data, the modem107restores the received bitstream by demodulating and decoding the signal fed from the beamforming RF transceiver100. For example, based on Orthogonal Frequency Division Multiplexing (OFDM), for the data transmission, the modem107generates the complex symbols by encoding and modulating the transmit bitstream, maps the complex symbols to subcarriers, and constructs OFDM symbols using Inverse Fast Fourier Transform (IFFT) and Cyclic Prefix (CP) addition. For the data reception, the modem107spits the signal fed from the beamforming RF transceiver100to the OFDM symbols, restores the signals mapped to the subcarriers using FFT, and restores the received bitstream by demodulating and decoding the signals. As such, the modem107and the beamforming RF transceiver100transmit and receive the signals. Hence, the modem107and the beamforming RF transceiver100can be referred to a transmitter, a receiver, a transceiver, or a communication part.

FIG. 2depicts an example RF transceiver according to this disclosure. Referring toFIG. 2, the QSG105ofFIG. 1is shown in detail. That is, the QSG105ofFIG. 1includes a synthesizer215for generating a local signal at the frequency fLO/M, an M-fold frequency multiplier213, and a QSG211for generating a quadrature signal. That is, the block210corresponds to the QSG105ofFIG. 1. InFIG. 2, functions of an N-way combiner201, an N-way divider202, an I/Q D-mixer204-1, an I/Q U-mixer204-2, and other elements are the same as the functions ofFIG. 1.

FIG. 3depicts an example RF transceiver according to this disclosure. Referring toFIG. 3, the QSG105ofFIG. 1is shown in detail. That is, the QSG105ofFIG. 1includes a synthesizer315for generating a local signal at the frequency (fLO*M), an M-fold frequency multiplier313, and a QSG311for generating a quadrature signal. That is, the block310corresponds to the QSG105ofFIG. 1. InFIG. 3, functions of an N-way combiner301, an N-way divider302, an I/Q D-mixer304-1, an I/Q U-mixer304-2, and other elements are the same as the functions ofFIG. 1.

FIG. 4depicts an example RF transceiver according to this disclosure. Referring toFIG. 4, the QSG105ofFIG. 1is shown in detail. That is, the QSG105ofFIG. 1is replaced by a synthesizer410including a Voltage Controlled Oscillator (VCO) for generating the quadrature signal. InFIG. 4, functions of an N-way combiner401, an N-way divider402, an I/Q D-mixer404-1, an I/Q U-mixer404-2, and other elements are the same as the functions ofFIG. 1.

FIG. 5depicts an example RF transceiver according to this disclosure. Referring toFIG. 5, the QSG510includes a 4-way divider514for dividing the signal generated at the frequency fLOto four signals, High Pass Filters (HPFs)513-1and513-4and Low Pass Filters (LPFs)513-2and513-3for generating a phase difference of 90 degrees at the frequency fLO, and amplifiers511-1through511-4for receiving the single signal from each of the HPFs513-1and513-4and the LPFs513-2and513-3and outputting a differential signal. InFIG. 5, functions of an I/Q D-mixer504-1and an I/Q U-mixer504-2are the same as the functions ofFIG. 1.

FIG. 6depicts an example RF transceiver according to this disclosure. Referring toFIG. 6, in a structure620for sharing P/Ss622-1through622-N in the transmitter and the receiver, switches621-1through621-N for selecting the transmitter and the receiver are added as many as RF chains. Like the switches114-1through114-N for selecting the transmitter and the receiver ofFIG. 1, the switches621-1through621-N for selecting the transmitter and the receiver is controlled by the RF controller106ofFIG. 1. An N-way divider and an N-way combiner include a single N-way bidirectional combiner/divider623allowing the bidirectional signaling. InFIG. 6, functions of an I/Q D-mixer604-1, an I/Q U-mixer604-2, the QSG610, and other elements are the same as the functions ofFIG. 1.

FIG. 7depicts an example RF transceiver according to this disclosure. Referring to FIG.7, with a small number of RF chains, a structure720uses a transmitting antenna and a receiving antenna individually. InFIG. 7, functions of an N-way combiner701, an N-way divider702, an I/Q D-mixer704-1, an I/Q U-mixer704-2, a QSG710, and other elements are the same as the functions ofFIG. 1.

FIG. 8depicts an example RF transceiver according to this disclosure. Referring toFIG. 8, with a small number of RF chains, a structure820uses the transmitting antenna and the receiving antenna individually. P/Ss831-1through831-N is shared by the transmitting antenna and the receiving antenna. Herein, switches832-1through832-N for selecting the transmitter and the receiver are used. The switches832-1through832-N for selecting the transmitter and the receiver is controlled by the RF controller106ofFIG. 1. An N-way divider and an N-way combiner include a single N-way bidirectional combiner/divider823allowing the bidirectional signaling. InFIG. 8, functions of an I/Q D-mixer804-1, an I/Q U-mixer804-2, a QSG810, and other elements are the same as the functions ofFIG. 1.

FIG. 9depicts an example N-way combiner or an example N-way divider according to this disclosure. Referring toFIG. 9, 16 chains include eight 2-way combiners/dividers, two 4-way combiners/dividers, and one 2-way combiner/divider in order.FIG. 10depicts an example N-way combiner or an example N-way divider according to this disclosure. Referring toFIG. 10, 16 chains include four 4-way combiners/dividers and one 4-way combiner/divider in order.

FIG. 11depicts an example N-way combiner or an example N-way divider according to this disclosure. Referring toFIG. 11, 16 chains include two 8-way combiners/dividers and one 2-way combiner/divider in order.FIG. 12depicts an example N-way combiner or an example N-way divider according to this disclosure. Referring toFIG. 12, 16 chains include one 16-way combiner/divider.

FIGS. 13A and 13Bare flowcharts of example operations of the RF transceiver according to this disclosure. Referring toFIG. 13A, the transmission method is explained. The I/Q U-mixer receives the signal from the modem in step1305. In step1315, the I/Q U-mixer up-mixes the quadrature local signal output from the QSG and the received signal to the RF signal. In step1320, the N-way divider divides the RF signal from the UQ U-mixer to N-ary RF signals of the same phase. Next, the P/S shifts the phase of the N-ary RF signals divided by the N-ary divider for the beamforming in step1325and transmits the signals over the antenna in step1330. Herein, the phase shifting for the beamforming and the transmission and reception mode change is performed by the RF controller.

Referring toFIG. 13B, the reception method is described. The beamforming RF receiver receives the signals from the antennas in step1355. In step1360, the LNA low-noise amplifies the received RF signals. In step1365, the PS shifts the phase of the RF signals amplified by the LNA, for the beamforming. In step1370, the N-way combiner combines the phase-shifted RF signals. Next, the I/Q D-mixer mixes the combined RF signal and the QSG output signal to the baseband signal in step1375and outputs the baseband signal to the modem in step1380.

FIG. 14is a block diagram of an example electronic device according to this disclosure. Referring toFIG. 14, the electronic device includes a memory1410, a processor unit1420, an input/output controller1440, a display1450, and an input device1460. Herein, a plurality of memories1410is included. The components are explained in detail. The memory1410includes a program storage1411for storing a program to control the operations of the electronic device, and a data storage1412for storing data generating in the program execution. The data storage1412stores data required to operate an application program1413and a switch and phase management program1414. The program storage1411includes the application program1413and the switch and phase management program1414. Herein, the program in the program storage1411is referred to as an instruction set which is a set of instructions.

The application program1413includes an application program running on the electronic device. That is, the application program1413includes instructions of the application run by the processor1422. The phase management program1414controls the P/S and the switch. That is, the phase management program1414determines the phase to shift for the beamforming and sends the phase information to the main controller of the modem. The phase management program1414determines whether the electronic device operates in the transmission mode or the reception mode, and sends the mode information to the main controller of the modem. The memory interface1421controls the access of the processor1422or a peripheral interface1423to the memory1410.

The peripheral interface1423controls connections between an input/output peripheral, and the processor1422and the memory interface1421. The processor1422controls to provide the corresponding service using at least one software program. The processor1422executes at least one program stored in the memory1410and provides the service corresponding to the program. The input/output controller1440provides an interface between the input/output device such as display1450and input device1460, and the peripheral interface1423. The display1450displays status information, an input character, a moving picture, and a still picture. For example, the display1450displays application program information of the processor1422.

The input device1460provides input data generated by selection of the electronic device to the processor unit1420through the input/output controller1440. The input device1460includes a keypad including at least one hardware button and a touch pad for detecting touch information. For example, the input device1460provides touch information such as touch, touch movement, and touch release detected by the touch pad, to the processor1422through the input/output controller1440. The electronic device includes a communication processor1490for voice communication and data communication. The communication processor1490includes the beamforming transceiver100and the modem107ofFIG. 1.

As set forth above, compared to the heterodyne structure requiring the IF stage, the present disclosure reduces the size and the power consumption. The present disclosure decreases the chip size by virtue of the transceiver which combines the transmitter and the receiver. Further, the same transmitting and receiving antenna reduces the antenna size and the RF package size. While the disclosure has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details is made therein without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents.