KR102060157B1 - Wireless repeater of broadband convergence service for 5g new radio - Google Patents

Abstract

The present invention relates to a repeater for a mobile communication terminal using a 5G new radio (NR) service band. More particularly, according to the present invention, provided is a broadband integrated service repeater for 5G NR, which comprises: a modem Rx block obtaining a system frame number (SFN) value and downlink (DL)/uplink (UL) shape information synchronized with a 10 m/sec frame boundary signal; and an RF interface block generating a switching signal through the SFN value and the DL/UL shape information received from the modem Rx block. The modem Rx block includes a field programmable gate array (FPGA) having a digital filter capable of detecting a peak value of power after passing only a sub-band value of an SSB block, and generating the DL/UL shape information as a waveform image.

Description

Broadband Integrated Services Repeater for 5G NR {WIRELESS REPEATER OF BROADBAND CONVERGENCE SERVICE FOR 5G NEW RADIO}

The present invention relates to a repeater design, and more specifically, a 5G NR broadband integrated service capable of applying a next generation communication method while overcoming limitations on the operating band of the terminal and power consumption of the terminal in transmitting and receiving a wideband signal. It is about a repeater.

Since the 2018 PyeongChang 2018 Olympic Winter Games 5G pilot service, Korean carriers are preparing to commercialize them, and there are attempts to commercialize them according to the high frequency characteristics of 5G worldwide.

In general, a repeater used in a communication system is a device used to extend coverage of a base station in a radio shadow area where a radio environment is degraded by natural or artificial obstacles, or to improve the quality of communication service in a high traffic area. It relays signals between the base station and the subscriber station.

Various mobile communication systems including mobile phones and personal mobile communication are largely comprised of a mobile switching center, a base station transceiver subsystem, and a mobile station, and each base station is a mobile communication terminal. Based on the radio wave strength and the call quality received by the receiver has a constant cell coverage (Cell coverage).

4G Long Term Evolution (LTE), called 4G mobile communication, provides faster data transmission speeds than existing 3G methods, and is now parallel but mostly transitioned to 4G.

In this regard, Korean Laid-Open Patent Publication No. 10-2016-0075160 discloses a conventional TDD type LTE wireless repeater, and FIG. 1 is a block diagram showing an operation of controlling the synchronization thereof.

Referring to FIG. 1, the synchronous control device 10 of a conventional time division wireless repeater includes a local oscillator 11 oscillating with a constant frequency signal, and an uplink RF signal when the uplink RF signal is transmitted through a coupler. A mixer 12 that mixes the signals of the local oscillator 11 and down-converts the baseband, an ADC 13 that converts the baseband signal of the mixer 12 into a digital signal, and a digital converted by the ADC 13. FPGA, which extracts OFDM pilot symbols related to synchronization from the time-division frame information through demodulation and generates a switch control signal for driving a first switch or a second switch switched in a downlink or uplink direction in the repeater. Field Programmable Gate Array) 15.

However, in order to provide 5G communication service, since it has a higher frequency characteristic than 4G communication already commercialized, more communication equipment is required, which may increase the burden on equipment investment cost of carriers. The shorter payback period is further deepened.

Therefore, the design of wideband TDD, support of bandwidth for NR (New Radio) service band at 5G operating frequency, high linearity and low power amplification, NSA / SA TDD Timing synchronization signal and Symbol Improvement of existing commercialized services such as rate extraction is required.

In particular, equipment suitable for the characteristics of 5G New Radio (hereinafter referred to as 'NR') should be applied.

 SUMMARY OF THE INVENTION The present invention has been made to overcome the above-mentioned problems of the prior art, and provides a traffic distribution system of an optical repeater that can flexibly adapt to traffic at an existing base station by improving a communication interface and configuration between a donor and a remote. For the purpose of

In order to solve the above problems, the present invention provides a modem Rx block for acquiring a system frame number (SFN) value and DL / UL shape information synchronized with a 10 msec frame boundary signal in a repeater for a mobile communication terminal using a 5G NR service band. 110 and an RF interface block 120 for generating a switching signal through the SFN value received from the modem Rx block and DL / UL shape information, wherein the modem Rx block passes only a band or less value of the SSB block. The present invention provides a broadband integrated service repeater for 5G NR, including an FPGA having a digital filter capable of detecting peak values of power, and generating DL / UL shape information into a waveform image.

According to the present invention, it is possible to utilize the equipment in the existing 4G communication and can be used as a common carrier (wideband) (280MHz) equipment carriers OPEX / CAPEX cost can be minimized to improve the economics.

In addition, by designing to use the RF block in common when using DL / UL not only increases the structural efficiency, but also has the effect of minimizing power consumption.

1 is a block diagram for explaining the operation of the TDD LTE wireless repeater in the prior art.
2 is a block diagram showing an embodiment of a broadband integrated service repeater for 5G NR according to the present invention.
3 is a view for explaining an example regarding the setting of such a center frequency.
Figure 4 is an experimental graph showing the effect of improving the ACLR when applying the APD chip.
5 is a block diagram illustrating the operation of a timing block in the broadband integrated service repeater for 5G NR of the present invention.
6 is a flowchart showing operations in a NAS network.
7 is a diagram illustrating operation timings of a modem reception block and an RF interface block.
8 is a block diagram illustrating a detailed structure and an interface of a sync block in the broadband integrated service repeater for 5G NR of the present invention.
9 is a diagram for explaining a state where the SSB is located and detected according to the number of symbols.
10 is a flowchart illustrating a method of generating a waveform image file and providing a local GUI / relay management system.

Hereinafter, a broadband integrated service repeater for 5G NR of a preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

However, the embodiments described below are merely to describe in detail enough to be able to easily carry out the invention by those skilled in the art to which the present invention pertains, thereby limiting the protection scope of the present invention It does not mean.

In the following description, when a part is 'connected' to another part, this includes not only a case in which the part is directly connected, but also a case in which another element or device is interposed therebetween. In addition, when a part is said to "include" a certain component, which means that it may further include other components, except to exclude other components unless otherwise stated.

2 is a block diagram showing an embodiment of a broadband integrated service repeater for 5G NR according to the present invention.

5G mobile communication systems are expected to support a variety of services such as enhanced Mobile BroadBand (eMBB), Ultra Reliable and Low Latency Communication (URLLC), and Enhanced Machine Type Communication (eMTC). It can be understood in the same context that specialized services such as Voice over Internet Protocol (VoIP) and Best Effort (BE) services are supported. In addition, 5G mobile communication systems are expected to support transmission time intervals (TTIs) of various lengths.

Dynamic TDD RF repeater in the 3.5GHz band, which has been recently auctioned for frequency, is a broadband (280MHz) equipment that can be used by carriers and minimizes the operator's OPEX / CAPEX cost. Dynamic TDD technology that meets the technical characteristics of NSA (Non Stand Alone) / SA (Stand Alone) standard is applied. The table below shows the major specifications to meet the common carrier and 5G NR technical standards.

Item standard Remarks Frequency band 3.42 to 3.7 GHz BW: 280 MHz Duplexing TDD Print DL 30 dBm Remote ANT terminal UL 23 dBm Base Station System Group Delay 2us Frequency tolerance 0.01 ppm 1dB / Step AGC range 40 dB Out of band ACLR 40dBc or more @ adjacent channel occupied bandwidth EVM Less than 3.5%@256QAM Error Vector Magnitude I / O characteristic impedance 50 ohm I / O VSWR 2: 1 or less Noise figure 6 dB or less Up Link Criteria

In the repeater for 3.5GHz 5G NR, a structure in a known repeater may be applied, so a description of basic elements will be omitted. Basically, it is desirable to reduce the efficiency, size and power consumption of the structure by using an RF block (arrow symbol) in common in the DL / UL when applied in the TDD (time division) method.

At this time, note that there is a need to maximize the isolation between DU / UL. Segregation between LNA and HPA of DL / UL paths ensures isolation between paths to prevent oscillation by frequency feedback. Securing isolation is also an important factor in preventing 5G EVM degradation using 256QAM. In addition, it may be desirable to separate the attenuation circuits for the inter-path gain control (AGC, ALC) so as not to affect the control time delay according to the DL / UL operation.

On the other hand, the power supply can be used with a built-in AC / DC Switch Mode Power Supply (SMPS), and the aerial can accommodate the existing legacy equipment when installed by applying a broadband duplexer with a SISO / Duplex structure.

As described above, the operating frequency is a 5G NR service band, and the support bandwidth is preferably at most 280MHz.

Examples of service bands and bandwidths are as follows.

NR band / SCS / BS Channel bandwidth NR band SCS 5 MHz 10 MHz 15 MHz 20 MHz 25 MHz 30 MHz 40 MHz 50 MHz 60 MHz 70 MHz 60 MHz 90 MHz 100 MHz kHz n78 15 Yes Yes Yes Yes 30 Yes Yes TBD Yes Yes Yes TBD Yes TBD Yes 60 Yes Yes Yes Yes Yes Yes Yes

On the other hand, the control of the PLL and the internal NCO frequency of the FPGA can be changed in units of 15KHz based on the center frequency and correspond to the changed center frequency.

3 shows an example of setting such a center frequency.

Based on 3GPP TS 38.104, the following center frequencies are supported.

Frequency range ΔFGlobal FREF-Offs [MHz] NREF-Offs Range of nref 0 to 3000 MHz 5 kHz 0 MHz 0 0 to 599999 3000 to 24250 MHz 15 kHz 3000 MHz 600000 600000 ~ 2016666 24250 to 100000 MHz 60 kHz 24250 MHz 2016667 2016667 ~ 3279167

Based on Table 3, the center frequency is determined as follows.

Accordingly, the center frequency is determined as 3000MHz + 15KHz (NREF-600000). Referring to FIG. 3, it can be seen that the frequencies of 100MHz BW of Banc C and Band D are set based on the center frequency.

On the other hand, Doherty method is applied to implement low power amplifier, and Asymmetircal Doherty method improves efficiency of about 7% compared to Symmetrical method.

In addition, by applying a filter for the removal of high frequency harmonic components, the terminal TR is designed to increase efficiency. Since the Dohety design application lowers the linearity of the amplifier, it is desirable to apply an APD chip to improve the linearity of the amplifier. At this time, since the maximum bandwidth of the APD chip is within 100MHz, it should be applied for each band, and the ACLR improvement effect in the specification of the APD chip and the maximum 100MHz bandwidth is shown in FIG.

Figure 4 is an experimental graph showing the effect of improving the ACLR when applying the APD chip.

Here, the test conditions are 34dBm PA output, 10.78% efficiency, PAPR 10db, LTE 20MHz 5FA, the bandwidth is basically fixed at 100MHz.

Referring to the drawings, the properties are shown below.

Fc: 3450MHz and 3550MHz

SBW: LTE 100MHz 1FA, PAPR 10dB

Pout: 34dBm, APD Apply

Current: 0.8A @ 29Vdc, 1Path

Efficiency: 10.8%

ACLR: 47dBc or more @ ± 100MHz

S / N and EVM characteristics according to the input level, 5G NR uses a wider signal than LTE, so at the same input level, the SNR is smaller than that of LTE. do.

division Input Level / SNR / EVM Correlation Remarks Input (dBm) -78 -73 -68 -63 -58 -53 -48 -43 -38 BW: 100 MHz S / N vs input 10 15 20 25 30 35 40 45 50 Repeater NF 6dB Assumption EVM (%) vs S / N 11.9 8.26 6.78 5.31 3.29 1.86 1.09 0.68 - Source EVM 0.35%

With APD linear technology, the EVM meets 3.5% at the DL maximum input condition and less than 5% at the minimum input condition.

5 is a block diagram illustrating the operation of a timing block in the broadband integrated service repeater for 5G NR of the present invention.

Radio frame structure based on 5G subcarrier spacing 30kHz can be arranged as shown in the table below.

μ SCS Number of Symbols
in 1 slot Slot number
in 1 radio frame Slot number
in 1 subframe 0 15 14 10 One One 30 14 20 2 2 60 14 40 4 3 120 14 80 8 4 140 14 160 16

In addition, Symbol and Cyclic Prefix Duration according to Subcarrier of 3.5GHz band are as follows.

Parameter / Numerology (μ 0 One 2 3 4 Subcarrier Spacing (KHz) 15 30 60 120 240 Symbol Duration (us) 66.67 33.33 16.67 8.33 4.17 Cyclic Prefix Duration (us) 4.69 2.34 1.17 0.57 0.29 OFDM Symbol including CP (us) 71.35 35.68 17.84 8.92 4.46

The timing module 100 may be composed of a modem Rx block 110 and an RF interface block 120. In the above frame structure, OFDM symbol allocation of a slot is performed by DL / UL switching according to a format used among slot formats. Eliminate unnecessary interference to neighboring cells due to 5G NR RF transmission and reception. The modem Rx block 110 obtains a 10msec frame boundary signal, a system frame number (SFN) value, and DL / UL slot information from the macro base station. The RF interface block 120 performs a function of generating a DL / UL switching signal using the provided information.

As shown, the NSA network implements processing functions for PSS, SSS, and PBCH transmitted from the LTE base station, generates SFN values synchronized with a 10 msec boundary signal, and provides them to the RF interface block 120. The PDCCH and PDSCH (SIB1) ), And extracts the synchronization information under the dynamic TDD condition by extracting the shape information on the DL / UL and the SFN value applied when changing the shape.

6 is a flowchart showing operations in a NAS network.

The SA network implements a processing function for SSB and Remaining Minimum System Information (RSI) transmitted from a 5G NR base station. After detecting the synchronization loss value (S101), as the value detected in the LTE PSS / SSS detection step (S100), synchronization with the 10 ms NR frame boundary signal (S110) is performed. When the synchronization is completed, in order to generate the SFN value synchronized with the boundary signal in the SFN value acquisition step (S200), LTE PBCH demodulation and decoding are performed and provided to the RF interface block 120.

Modem reception block is demodulated and decoded to obtain RMSI configuration information through MIB (Master Information Block) transmitted from NR base station, and to implement processing functions for NR PDCCH and PDSCH (SIB1: System Information Block Type I) (S210). Go through). Accordingly, through the DL / UL shape information acquisition step (S220), the RF interface block 120 provides the shape information and the SFN value applied when changing the shape of the 5G DL / UL.

When the shape is changed through the determination of whether the initial setting or the DL / UL shape is changed (S230), the process of generating or regenerating the RF Block DL / UL switching signal is performed in the switching signal generation step (S300).

7 is a diagram illustrating operation timings of a modem reception block and an RF interface block.

Here, the output to the RF interface block 120 according to the on-off signal of the DL and the on-off signal of the UL is shown, and the symbols of the DL / UL are shown.

The synchronization block using the LTE modem and the 5G NR modem can minimize the cost and power consumption in the NSA and SA environments, and enable the dynamic TDD implementation to maximize the frequency utilization efficiency among the 5G required technologies.

8 is a block diagram illustrating a detailed structure and an interface of a sync block in a broadband integrated service repeater for 5G NR of the present invention.

The RF splitter 2100 connected to the antenna port 2010 is connected to the sync block, and DL / UL is connected through the interface connector 2500 through the RF front end 2200, the RF receiver 2300, and the FPGA 2400. Controlled.

Meanwhile, in order to maintain a constant RF gain regardless of the RB number ratio of the 5G NR DL signal, it is necessary to detect power independent of the RB number.

In the existing LTE, peak detectors are selected as peak detector values by selecting peak values on the time axis by implementing peak detectors. Since the LTE DL signal has a section in which PDCCH is allocated to all subcarriers even in 0RB, the highest value among the detector values can be used as the peak detector value.

However, in 5G NR, only the SSB signal is always transmitted. In the case of 0RB, no signal is allocated to all subcarriers, so an error may occur when using the above method.

Therefore, in order to reduce the error of the peak detector, the present invention proposes a method of detecting a peak value after passing only BW or less of the SSB block by implementing a digital filter in the FPGA to detect only the power portion of the SSB signal portion. do.

The SSB Symbol Case when the subcarrier spacing is 30 KHz and the frequency is 3 GHz <f ≤ 6 GHz is as follows.

SCS OFDM Symbol 3 GHz <f ≤ 6 GHz Case B: 30KHz {4,8,16,20} + 28n n = 0, 1 S = 4, 8, 16, 20, 32, 36, 44, 48
(Lmax = 8) Case C: 30KHz {2,8] + 14n n = 0, 1, 2, 3 S = 2, 8, 16, 22, 30, 36, 44, 50
(Lmax = 8)

The SSB is located according to the symbol number and the subcarrier number (frequency) may vary. That is, the position of the SSB can be changed on the frequency side, and the peak position detection is performed by changing the position of the filter passing the SSB as follows.

9 is a diagram for explaining a state in which the SSB is located and detected according to the number of symbols.

The DL and UL output waveforms are visualized so that sample data before and after the digital filter can be stored for visualization through FFT. Since the present technology uses DL and UL as common paths, it is possible to visualize a desired signal by determining the DL and UL intervals through the switching signal input from the Timing Module. Also, it uses CPL port of Service ANT and Donor ANT through RF Transceiver.

By controlling the RF Transceiver, you can set the band you want to measure to visualize the signal in the desired band. The monitoring method through Donor ANT and Service ANT CPL Port is proposed as follows.

The path to be measured in the MCPU is selected (S1100), and 2) after the measurement start signal is transmitted through the MCPU FPGA (S1200), a signal of a predetermined section is stored in the block memory (S1300). The value calculated in the FFT process (S2100) is transferred to the MCPU (S2200). The received value is displayed on the GUI (S3100).

At this time, Sampling Clock uses 153.6MHz, and when 5120 samples are FFT processed (Span 153.6MHz, RBW 30KHz) to display time domain signal, the signal before FFT processing is received and displayed on GUI.

Waveform image file generation and local GUI / repeater management system providing method is as follows, Figure 10 is a flow diagram for this.

The control unit generates the waveform image using the raw data sampled in the digital unit, and takes the average of the FFT processed data a certain number of times. The average value is then saved and the image file can be created using the GNUPLOT program.

The number of images that can be accumulated can be changed according to the storage space. The waveform image can be saved before and after the alarm in case of over output or oscillation. The following is the signal waveform generated by the above method, and the file can be created and saved under the operator's control.

The above specifications for configuring the equipment of the present invention can be proposed as follows.

Item suggestion Remarks Size (mm) 208 x 420 x 84 W x H x D
(Except BRK) Volume 7.3 Excluding BRK Weight (Kg) 6.7 kg Excluding BRK Power Consumption (W) 83.9 W

The working temperature range is -5 to +50, and the humidity is preferably 5 to 90%. The input power may be 220 VAC, and it would be desirable to design a compact size with a minimum width to facilitate installation in the building.

In the above, the present invention has been described in detail based on the embodiments and the accompanying drawings. However, the scope of the present invention is not limited by the above embodiments and drawings, and the scope of the present invention will be limited only by the contents described in the claims below.

Timing module 110 ... Modem Rx block
120 ... RF interface block

Claims (1)

In a repeater for a mobile communication terminal using a 5G NR service band,
A modem Rx block 110 for acquiring a system frame number (SFN) value and DL / UL shape information synchronized with a 10 msec frame boundary signal as the LTE PSS / SSS value detected after detecting the synchronization loss value; And
It includes a timing module 100 consisting of; RF interface block 120 for generating a switching signal through the SFN value and DL / UL shape information received from the modem Rx block,
The timing module,
The paths for DL and DU are used in common, but the LNA and HPA are separated and isolated to prevent oscillation due to frequency feedback, and the attenuation circuit for gain control is separated to remove the influence of delay time of DL and UL. An FPGA having a digital filter capable of detecting a peak value of power after passing only a value below a set bandwidth so as to reduce a peak detector error of an SSB block, and selecting a path to be measured in an MCPU. If 5G NR broadband integrated service repeater to generate a waveform image of the shape information for the DL section and the UL section through the switching signal and to store and visualize the sample data before and after the digital filter.

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