KR20000012806A - method for shaping a beam and system for performming the same - Google Patents

Abstract

PURPOSE: An adaptive beam forming method for adding against binary data of receipt radio wave and controlling radio frequency transmit-receive signal integer and a digital beam former are provided to prevent channel interference and sustain optimum receipt state. CONSTITUTION: The adaptive beam forming method for adding against binary data of receipt radio wave and controlling radio frequency transmit-receive signal integer comprises: a step converting analog signal input from plural antennas(110a-110n) into digital signal; a step processing said receipt signals to generate initial adding value; a step operating sequential updated adding values generated in each sample period; a step comparing the initial adding value with the updated adding value, then correcting the adding value; and a step controlling amplifying units(120a-120n), band pass filtering units(130a-130n) and converting units(140a-140n) by the data formed by the new adding value.

Description

Adaptive beam shaping method and digital beam shaping machine which combines weighting of binary data of received radio waves and adjustment of radio frequency transmission / reception signal constants {method for shaping a beam and system for performming the same}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adaptive beamforming method and a digital beamformer that combines weighting of binary data of received radio waves and adjustment of radio frequency (RF) transmission and reception signal constants.

In general, the first and second generation mobile communication base stations have a three-sector steel tower structure and a plurality of radiating elements in order to have an omnidirectional beam radiation pattern up to a certain distance from which the communication service is available. In addition to poor reception due to obstacles or bad weather on the path, the Doppler effect of the transmission frequency of the moving body causes a frequency shift according to the moving speed.

This phenomenon causes mobile phone users to experience poor service conditions such as 1) interference, 2) reflections, 3) noise, and 4) unauthorized disconnection, and decreases the efficiency of the base station by adversely affecting the system performance of the base station. Shortening the lifespan, it is difficult to provide high-quality services including voice services and multimedia transmission services. In addition, additional construction is required by slightly tilting the antenna element fixed to the tower in order to expand the effective radiation range per base station, and at the same time, measuring the radiated field strength or adjusting the system parameters to secure the proper beam range and direction. There is an additional effort. In addition, in the base station employing the CDMA method, the power control by the near-far effect is required along with the movement of a plurality of terminals in a single cell, and a separate interference canceller and a channel equalizer are used for the demodulation process of the base station. Therefore, the beam required by the next-generation mobile communication base station system to provide high quality services such as data and multimedia services always needs a digital beam former to secure a directing point and a certain level of gain against the poor link conditions of the receiving environment. Doing. Digital beam formers can significantly reduce the cost per base station while increasing subscriber capacity per base station, improving communication quality, increasing the amount of effective radiated power, and increasing effective beam coverage. However, unlike the conventional single system, the digital beam former is flexible in the properties of TDMA / CDMA system or synchronous / asynchronous system unlike the existing single system to provide high quality service including data or multimedia transmission service. In addition, there is a need for a system that has a highly scalable system structure regardless of the increase or decrease of the number of antennas, employs a system bus and can be connected to an operator's server externally.

The present invention has been invented to meet the above needs, and the first object of the present invention is to meet the wireless connection and communication quality required by the next generation mobile communication base station system and to accommodate various types of system types. Information necessary to secure directivity to the origin of the terminals while eliminating unnecessary interference signals and multiple irregularly reflected signals due to multipath fading with the received states of radio waves detected from signals received through the phased array antenna It is to provide a digital beam shaping method for performing extraction, beam shaping, and adjustment of RF parameters. A second object of the present invention is to provide a system for performing the first object.

1 is a functional block diagram for illustrating a digital beam forming system according to the present invention.

2 is a flow diagram for explaining the operation of the digital beam shaping system according to the present invention.

The digital beam shaping method of the present invention for performing the first object comprises the steps of: 1) converting an analog signal input through a plurality of antennas into a digital signal; 2) generating an initial weight by processing a plurality of initially received radio signals; 3) calculating update weights, which are instantaneous actual values calculated at every sampling period, for amplitude and frequency constants of the plurality of radio signals received through the plurality of antennas after the initial weights; 4) When the update weight is generated, compare the initial weight and the update weight, and create a new weight by performing weight correction to reduce the correction value (-) if the update weight is large and to add the correction value (+) if the update weight is small. Doing; 5) converting the RF constants to prevent channel interference and maintain an optimal reception state by controlling the amplifier, the bandpass filter, and the converter by the beam-formed data according to the generated new weights. In addition, the digital beam shaping system of the present invention for performing the second object, 1) an amplifying unit for amplifying and transmitting a signal on the output side of the antenna for transmitting and receiving electromagnetic waves, 2) a suitable signal band according to the transmission and reception 2. A communication system comprising: a band pass filter and a conversion unit for passing a signal; and 3) an ADC unit for analog-to-digital conversion of a signal output from the conversion unit, and 4) a DAC unit for digital-analog conversion. It has a serial or parallel signal transmission structure according to, 5) a system bus for transferring data to each device constituting the system; Connected to an output side of the system bus, an analog signal input from each antenna is input as a digitally converted signal from each device, and demodulated a plurality of signals, and then an amplitude distribution and a frequency error are collected to create an instantaneous distribution chart. A weight processor for generating a weight vector required for beam shaping; 7) a beam shaping unit for storing the weights outputted from the weight processing unit and calculating data for adjustment of RF transmission / reception parameters by calculating stored weights and data which are continuously inputted later; 8) a correction unit which controls the operation of an amplifier, a band pass filter, and a converter configured to receive the data output from the beam shaping unit through a system bus and constitute an RF transceiver; And 9) is connected to the output side of the system bus and checks the operation of the system bus and the status of each device to the operator server, and the control unit for controlling the operation of each component in accordance with the operator's action.

The present invention has the reception states of radio waves from signals received through multiple phased array antennas, eliminates unnecessary interference signals and multiple irregularly reflected signals due to multipath fading, and at the same time, directs the origins of terminals. Performs information extraction, beam shaping and adjustment functions required for securing.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 is a block diagram illustrating a digital beam forming system according to the present invention, and FIG. 2 is a flowchart illustrating the operation of the digital beam forming system according to the present invention.

As shown in FIG. 1, the digital beamforming system according to the present invention is arranged in a linear or planar shape at intervals of λ / 2 in a mobile communication base station and amplified at the output sides of the antennas 110a to 110n for transmitting and receiving electromagnetic waves, respectively. The parts 120a-120n are connected. The amplifiers 120a-120n are noises in the power components of the HPA unit and the signals received from the antennas 110a-110n, which are high output amplifiers that amplify the power of signals transmitted to the antennas 110a-110n according to a wireless connection standard. It consists of an LNA unit, which is a low noise amplifier that amplifies only the signal while suppressing the signal. Band-pass filters 130a-130n for selecting and outputting transmission and reception signals output through the antennas 110a-110n are connected to the output sides of the amplifiers 120a-120n. The band pass filters 130a to 130n are band pass filters that pass only received signal components that conform to the communication channel specification, and a band pass filter that removes components generated out of the transmission signal band conforming to the communication channel specification. It consists of a band rejection filter (BRF). To the output side of the band pass filter 130a-130n, converters 140a-140n for converting frequency bands in accordance with transmission and reception signals are connected. The converters 140a to 140n sense UPC, which is a frequency upconverter that multiplies a 70 MHz intermediate frequency transmission signal to a next generation mobile communication frequency band signal, and a frequency for receiving a received signal in the next generation mobile communication frequency band in a lower direction of 70 MHz. DNC, which is a down converter.

On the output side of the converters 140a-140n, an analog signal received from the frequency down converter is appropriately gain-controlled, and then converted into a digital signal and outputted to the system bus 170, which is an input / output path of data, to the ADC 160a-. 160n) and DACs 150a-150n, which are converters for converting digital signals output from the system bus 170 to analog signals and synthesizing the IQ channels and outputting them to the frequency upconverter. On the output side of the system bus 170, a plurality of analog signals inputted from each antenna 110a-110n are digitally received through the system bus 170 through an amplifier, a band pass filter, and an ADC. After demodulating the signals of the signal, the weight processor 190 and the weight processor 190 for generating an instantaneous distribution map by collecting the amplitude and frequency errors determined in the first process of digital beam shaping, and then generating a weight vector for beam shaping. The beam shaping unit 180 is connected to store the weights outputted from and to generate the data necessary for adjusting the RF transmission / reception parameters by calculating the stored weights and the data continuously input later. In addition, the system bus 170 includes amplifiers 120a-120n and band pass filter 130a-120n constituting an RF transceiver with data output from the beamforming unit 180 by the calculation of the weight processor 190. And a correction unit 220 for controlling the operations of the conversion units 140a-140n.

On the output side of the system bus 170, the control unit 200 that manages the system bus 170, checks the status of each component board, reports it to the operator server 210, and controls the operation of each component according to the operator's action. Connected.

Here, the system bus 170 has a serial or parallel signal transmission structure along the signal flow, and transmits data to each device constituting the digital beam shaping system. The detailed operation of the digital beam forming apparatus according to the present invention having such a configuration will be described with reference to FIG. 2.

The digital beamforming system according to the present invention is suitable for a next generation mobile communication (IMT-2000) base station that provides a plurality of terminals to data transmission service and multimedia transmission service in addition to voice telephone which is the mainstream of the existing first and second generation mobile communication service. It is designed to. First, referring to FIG. 1, a plurality of radiating elements, not single antennas, are arranged at intervals of half wavelength (λ / 2) to input from phased array antennas 110a-110n so as to maintain a constant phase difference with respect to a remote radioactive radiation source. The analog signal is amplified only by the LNA section of the amplifier 120a-120n while suppressing noise in the power component and is input to the band pass filter 130a-130n. The BPF section of the band pass filtering section 130a-130n passes only the received signal components conforming to the communication channel standard and inputs them to the converting section 140a-140n. The DNC of the converting units 140a to 140n senses the received signal in the mobile communication frequency band in a lower direction of 70 MHz and inputs it to the ADCs 160a to 160n, and the digitally converted signal through the ADCs 160a to 160n is a system. It is output to the bus 170. In addition, the digital signal output from the system bus 170 is converted into an analog signal in the DAC (150a-150n), and the intermediate frequency transmission signal of 70MHz in the UPC of the converter (140a-140n) as a mobile communication frequency band signal In order to multiply in the direction, components generated out of the transmission signal band conforming to the communication channel specification are removed from the BRFs of the band pass filter units 130a to 130n and input to the amplifiers 120a to 120n. The HPA section of the amplifying section 120a-120n amplifies and outputs the power of the signal transmitted to the antennas 110a-110n according to the wireless connection standard.

In the mobile communication base station to which the signal is transmitted as described above, the digital beamforming system according to the present invention adds a zero of a beam to the direction of the interference signal or the direction of the multipath fading signal. To shape the beam emitted from

Referring back to FIG. 2, the analog signals received through the phased array antennas 110a-110n through the above-described process are converted into digital signals (steps S101-S102) through the system bus 170. After the power is applied to the system, the weight processing unit 190 receiving the digital signal received through -110n generates the initial weight by processing the plurality of radio signals received for the first time (step S103). Is the state of the first received radio wave signal, and is the weight calculated through the process of bottom-up squared average algorithm for amplitude and frequency constants at the first sampling point. It becomes the reference value for updating.

After generating the initial weights, the weight processing unit 190 samples each amplitude and frequency constant as a determination value for the state change of the plurality of radio signals received through the respective antennas 110a-110n after the initial weight. For each period, an update weight which is an instantaneous measured value calculated as a result is calculated through a process of a bottom-up squared average algorithm (step S104).

When the update weight is calculated, the amplitude and frequency error of the weight vector are calculated as +, 0,-in each sampling interval in the analog-to-digital conversion process. The device is constructed by designating the vertical axis as the instantaneous weight. That is, the weight processor 190 reads signal values every cycle from n input buffers, obtains an average value, and then instantaneous errors (average values −) of signals received through the antennas 110a-110n based on the average values. And then assign an average weight of 0.5 to the channel of the error with zero error, assign a maximum weight of 1 to the largest-error, and assign a minimum weight of 0 to the largest + error. The update weight vector is generated by assigning weights to 1/10 of the calculated value by normalizing the errors.

When the update weight is generated, the weight processor 190 compares the initial weight and the update weight (step S105), and if the update weight is large, decreases the correction value (-) and adds the correction value (+) if the update weight is small. Correction is performed (steps S106 to S107), that is, the weight processing unit 190 gives data of one word in the row direction to the weight vector generated for each channel and is unique in the column direction. By assigning the sequence numbers and storing them in the buffer, a weighted page, which is one storage unit, is generated. Whenever the average value of the generated weighting page is collected in units of 10 times and the re-average is calculated, if the update weight value is greater than the initial weight value, a (+) sign is given and if it is less, a (-) sign is assigned to the weight generated. When the update weight is large, the correction value of 1/100 is reduced (-), and when the update weight is small, the operation is performed to generate a new weight (step S108).

When a new weight is generated as a result of the weight processing unit 190, the beam shaping unit 180 buffers data for correcting the shape of the beam radiated from the antennas 110a-110n according to the weight processed by the weight processing unit 190. An operation of shaping the beam is performed by outputting the correction to the correction unit 220 through 170. (S109-S130) In other words, the beam shaping unit 180 may perform the digital transformation of the signals converted by the weight processing unit 190. For signals with zero frequency error in the signal band, the number of antennas in the memory is stored in n buffers, and data is simultaneously extracted from each buffer, and the extracted data are simultaneously weighted by n digital signal processors. The data for beam shaping is output to the system buffer 170 through a continuous calculation process of multiplication and addition of the weighted value and data input through the antennas 110a-110n. The. In addition, the correction unit 220 may use the amplification unit 120a-120n, the band pass filter 130a-130n, and the conversion unit 140a-140n based on the data output from the beam shaping unit 180 to the system buffer 170. ) To convert RF constants. That is, the beam shaping unit 180 analyzes input signals of n antennas, extracts a spectrum in which image components of adjacent cells or completely different frequencies appear in the signal band with respect to the cell frequency used by the base station. Channels detected with a value exceeding 10% of the spectrum are outputted to the weight processor 190 so as to give a special weight of 0, and a signal is output to the corrector 220 to amplify parts 120a to 120n of the channel. By adjusting the RF constant, the transmission power amplification degree outputted from the amplification units 120a to 120n of the channel is reduced to 1/10 to prevent the channel interference so that the wireless connection of the component causing the channel interference cannot be made. In addition, the correction unit 220 according to the data output from the beam shaping unit 180 to the system buffer 170, the amplification unit (120a-120n), band pass filter (130a-130n) and the conversion unit (140a-140n) ) To generate information to increase or decrease the amplification and gain of the transmit / receive amplifier, which affects the magnitude of the transmit / receive electric field strength, in units of 1/10, respectively, and the converters 140a to 140n and the band pass filter 130a. The carrier frequency and the signal bandwidth of -130n) are generated to be corrected according to the frequency plan value input from the operator server 210 through the control unit 200.

As described above, the digital beamforming system according to the present invention can be implemented at low cost with a slight system change with existing first and second generation mobile communication base stations, and a new third generation mobile employing a phased array antenna. Even in the case of a communication base station, it is implemented to always maintain an optimal reception state regardless of the deterioration of the radio wave environment, thereby greatly improving demodulation performance, thereby increasing subscriber capacity per base station, improving communication quality, and improving the amount of effective radiated power. Increasing and extending effective beam coverage while providing significant cost savings per base station.

In addition, since the RF constants of the base station are adjusted as the beam is electronically formed, monitoring and control of the state of the system can be performed, thereby increasing the reliability and availability of the next generation mobile communication base station system. Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited thereto and may be improved or modified by those skilled in the art within the scope of the technical idea of the present invention.

Claims (7)

Iii) converting analog signals input through the plurality of antennas 110a-110n into digital signals; Ii) processing the plurality of radio signals first received in the step to generate an initial weight; Iii) calculating update weights, which are instantaneous actual values calculated at every sampling period, for amplitude and frequency constants of a plurality of radio signals received through the plurality of antennas 110a-110n after the initial weights; 갱신) When the update weight is generated in the above step, the initial weight and the update weight are compared, and if the update weight is large, the correction value is reduced (-), and if the update weight is small, the weight correction is performed to add the correction value (+). Generating a weight; Iii) Control the amplifiers 120a-120n, the band pass filters 130a-130n, and the converters 140a-140n according to the beam-formed data based on the new weights generated in the above step to prevent and optimize the channel interference. Converting the RF constant so that the reception constant of the received radio wave is weighted to the binary data of the received radio wave and adjusting the RF transmission / reception signal constant. 2. The weighting of the binary data of the received radio wave according to claim 1, wherein the initial weights of step ii are calculated through a process of a bottom-up squared average algorithm for amplitude and frequency constants at the first sampling time. An adaptive beamforming method that adjusts the RF transmit / receive signal constants in parallel. 2. The method of claim 1, wherein the update weight of step VII is a bottom-up squared average algorithm for each sampling period for amplitude and frequency constants of a plurality of radio signals received through the antennas 110a-110n after the initial weight. An adaptive beamforming method comprising the weighting of binary data of a received radio wave and an adjustment of an RF transmission / reception signal constant, which are calculated through a process. 2. The weight saving method of claim 1, wherein the step V stores the weight vector generated for each channel in a buffer by assigning one word of data in a column direction and a unique order in a row direction. Generating a page; Whenever the average value of the generated weight page is collected in ten units and the re-average is calculated, the weight is generated by giving a positive sign if the update weight value is greater than the initial weight value and giving a negative sign if the update weight value is smaller than the initial weight value. step; Performing a step of subtracting a correction value of 1/100 to the generated weight if the update weight is large and adding it if the update weight is small. An adaptive beamforming method that adjusts the weighting and the RF transmission / reception signal constants. The method of claim 1, wherein the channel interference prevention operation of step VII analyzes the input signals of the plurality of antennas (110a-110n) to analyze the spectrum in which image components of a frequency completely different from the cell frequency used by the base station appear in the signal band. Extracting; And applying a special weight of 0 to the channel where the spectrum is detected with a value exceeding 10%, and reducing the transmit power amplification degree output from the amplifier of the channel to 1/10. Way. 2. The method of claim 1, wherein the adjustment of the RF constants in step VII generates information to increase or decrease the amplification and gain of the transmit / receive amplifiers in units of 1/10, respectively, which affect the magnitude of the transmit / receive electric field intensity by the beamforming data. And correcting the carrier frequency and the signal bandwidth according to the input frequency plan value. Amplifying units 120a-120n for amplifying and transmitting signals on the output side of the antennas 110a-110n for transmitting and receiving electromagnetic waves, band pass filtering units 130a-130n for passing a suitable signal band according to transmission and reception; Digital-to-Analog Conversion of the Converters 140a to 140n and the ADCs 160a to 160n and the Converters 140a to 140n for Analog-Digital Conversion of the Signals Output from the Converters 140a to 140n In the communication system consisting of a DAC (150a-150n) for, A system bus 170 having a serial or parallel signal transmission structure along the signal flow, for transferring data to each device constituting the system; It is connected to the output side of the system bus 170 and receives the analog signal input from each antenna (110a-110n) as a digitally converted signal from each device to demodulate a plurality of signals, and then amplitude amplitude and frequency errors A weight processing unit 190 which collects the instantaneous distribution and then generates a weight vector for beam shaping; A beam shaping unit (180) for storing the weight outputted from the weight processing unit (190), and calculating data for adjustment of RF transmission / reception parameters by calculating stored weights and data which are subsequently input; The amplifiers 120a-120n, the band pass filter 130a-130n, and the converter configured to receive the data output from the beam shaping unit 180 through the system bus 170 to form an RF transceiver. A correction unit 220 for controlling the operations of the 140a to 140n; And, A control unit connected to an output side of the system bus 170 to check the operation of the system bus 170 and the status of each device to report to the operator server 210, and to control the operation of each component in accordance with the operator's action And a digital beam shaping device configured to simultaneously adjust the weighting of the binary data of the received radio wave and the adjustment of the RF transmission / reception signal constant.