KR20190129451A - Wireless bridge method - Google Patents

Abstract

The present invention relates to a wireless bridge method. According to an embodiment of the present invention, the wireless bridge method comprises a step of using a micrometer wave band.

Description

Wireless Bridge Method {WIRELESS BRIDGE METHOD}

An embodiment of the present invention relates to a wireless bridge method using a V-band, 64-71 GHz and 1.25 Gbps.

-M / W frequency is defined as high frequency band frequency of 3 ~ 90 GHz band used for high speed large capacity fixed communication such as relay between station, inter-building and mobile backhaul.

-M / W system refers to broadcasting program and communication relay system used in island area, mountain section, urban shade area, etc. where wired network is difficult to build. The frequency used is called M / W frequency.

-It can be said that there is a slight difference from M / W frequency of conventional concept in that M / W frequency includes not only fixed relay frequency but also mobile broadcasting relay frequency.

-The 57 ~ 64GHz band is allocated for unlicensed frequency use, so it is used for wireless fixed point-to-point communication because most countries do not have the cost of using the frequency.

-Prototype 64 ~ 71GHz frequency band is newly opened as FCC Unlicensed band (unlicensed band)

A wavelength shorter than the new assigned frequency than the reference frequency band;

-Frequency bands available for fixed wireless links in the frequency band above 10 GHz are the 10 to 40 GHz band, which is the traditional band, 60 GHz (57 to 64 GHz) and the millimeter wave band, 70/80 GHz (71 to 76/81 to 86 GHz). Bands and the like. Microwave bands, which have been used for fixed communications for decades, are currently 10 GHz or more combined with over 90 GHz of the global wireless mobile backhaul market.

-Newly allocated channel width is allocated to> 100MHz.

-There are four subdivided uses for disaster recovery service, telecommunication business and fixed broadcasting relay, self-communication communication, telecommunication business, self-communication broadcasting and broadcasting relay included in telecommunication facilities. For broadcast program relay, it corresponds to M / W band.

-As the frequency is allocated and used for military purposes, military satellite communication of 12-45GHz station, vehicle-mounted military radar electronic warfare weapon and missile weighting device of 3-95GHz station have been studied and will be used in military and aerospace fields. .

-Based on the 60GHz band, it can be applied to hidden satellite communication without eavesdropping from terrestrial base stations.

In order to meet the characteristics of 5G services requiring low transmission delay, interest in using the mmWave band is expanding.

-In the future, demand for wireless backhaul using mmWave band is expected to increase faster than existing wired hall, microwave and satellite.

-The possibility of using and expanding the broadband mobile service and the wireless backhaul in the mmWave band including the 60 GHz band is increasing.

-The interest in using the mmWave band is expanding to meet the characteristics of 5G services requiring low transmission delay.

1) Technical necessity

-Establishment of continuous R & D base for domestic microwave-based wireless backhaul products and element technologies, which are relatively lacking in technology and product development compared to the stable global market size.

-Increasing the synergy effect of technology commercialization by integrating global technology with continuous development investment in mobile communication, mobile terminal and short-range wireless communication.

-Strengthen the competitiveness of core technology products for the implementation of point-to-point solutions, which are relatively in use but are expected to be the core of mobile communication networks.

-Creation of various application models based on the basic technology and core technology will increase sales, activate the industry, create a continuous development environment, and form a virtuous cycle of dynamic development, which will lead to the increase of sales

-Recently, interest and research on the use of mm-wave band for point-to-point solution and 1.25Gbps broadband wireless transmission have increased, and it is expected that a full-scale market will be formed from 2019. Advance development.

-Increased awareness of the necessity of mass transmission-based wireless communication technology and the importance of related technologies.

-ASK modulation system that is applied to V-band 64 ~ 71GHz millimeter wave band wideband wireless repeater is designed / manufactured to support ultra low delay and 1.25Gbps broadband by upgrading RF module specification. Occupied bandwidth is reduced, transmission speed is increased.

A wireless bridge method according to an embodiment of the present invention includes using a micrometer wave band.

The effect of the wireless bridge method according to the present invention will be described.

 Wireless repeater products in the millimeter-wave band (57-71 GHz, V-band) and (71-86 GHz, E-band) are considered the most suitable for backhaul for next-generation 5G mobile communications, and are able to handle the rapidly increasing data demand. Can be seen as the only alternative.

 In particular, the 64 ~ 71GHz frequency band to be developed through this project has been newly opened as FCC Unlicensed band (unlicensed band), and has a frequency characteristic that enables communication with longer transmission distance than the existing 57 ~ 64GHz frequency band.

 The radio repeater products are difficult to imitate in a short time due to the difficulty of designing parts and systems due to the high frequency band characteristics, and because of the high technical know-how required, there are not many companies worldwide dealing with the band, and newly allocated 64 ~ 71GHz In the case of products, it is possible to preoccupy the market since there are no products on the market yet.

 By using ASK modulation method, we will realize the world's best transmission latency of about 20ns, which can be highlighted as a strength in financial market and various market areas where real-time network is vital.

  Technology effect

-Currently, the US occupies more than 95% of the global market for millimeter-band Gbps wireless transmission systems. The development of this technology is expected to raise the competitiveness of domestic industrial technologies and products to the level of advanced countries.

-As domestic manufacturers are unable to secure this technology due to lack of technology and development manpower, it is possible to improve the technology of Korean companies by providing this technology and secure export competitiveness.

-As domestic companies are more competitive than foreign companies in terms of follow-up management of systems, it is expected that they can control 85% of the domestic market if they have technological competitiveness.

Figure 1. 64-71 GHz Wireless Bridge BLOCK DIAGRAM
Fig. 2, SPF Transceiver Type
Figure 3. Optical transceiver conceptual diagram
Figure 4. Communication Connector
Figure 5. Digital Structure
Figure 6.Modulator Block Diagram
Figure 7. Demodulator Block Diagram
8. Modulator Functional Diagram
9. Demodulator Function Configuration
Figure 10. V-band Transceiver Block Diagram
11. Frequency up-conversion unit
12. Frequency down converter
13. PLL generator
Figure 14. PLL Module Configuration
Fig. 15 Phase Noise Specification
Figure 16. Emitter-coupled Swithch circuit
Figure 17. Push-Push Connection Circuit
Figure 18. Drive AMP design
19. Filter; (a) LPF (Low Pass Filter), (b) BPF (Band Pass Filter: Bandpass Filter), (c) HPF (High Pass Filter: High Pass Filter), (d) BSF (Band Stop Filter) , BRF-Band Reject Filter, Notch Filter: Bandstop Filter)
20. Power AMP unit design
Figure 21. Power divider / synthesizer design
Figure 22. Diplexer block diagram
Figure 23. Frequency spectrum
Figure 24. Diplexer Configuration
25. Waveguide Microstrip Stereo View
Figure 26. Microstrip Structure
27. Microstrip Features
28. MCU Module Part
Figure 29. DC / DC Block Diagram

The following detailed description is provided to assist in a comprehensive understanding of the methods, devices, and systems described herein. However, this is only an example and the present invention is not limited thereto.

In the following description, terms to be described below are terms defined in consideration of functions in the present invention, which may vary according to a user's or operator's intention or custom. Therefore, the definition should be made based on the contents throughout the specification. The terminology used in the description is for the purpose of describing particular embodiments only and should not be limiting. Singular expressions include plural expressions unless the context clearly indicates otherwise.

V-Band Applications

■ 3G / 4G / 5G Mobile Network Wireless Backhaul Transmitter

■ High speed network backhaul transmission device between corporate and school buildings

■ Network transmission device for disaster prevention

■ Voice and data communication in environments where communication infrastructures such as air, sea, desert, and polar regions are difficult to create, and in disasters such as volcanoes, earthquakes, and buildings collapse

■ Broadband broadcasting / communication convergence service such as high-speed internet for the remote areas of informatization such as island wallpapers and mountain areas

■ Global 5G mobile radio transmission equipment (3.5GHz, 28GHz)

■ military network

-Main application field is wireless backhaul link solution of 4G LTE / 5G mobile communication network

<Technical Development Contents>

o Developed V-band, 64-71GHz 1.25Gbps Wireless Bridge device

o ASK Transceiver implementation

-Frequency up converter

-Frequency down converter design

-Power AMP part design

-Power divider / synthesizer design

o Design of frequency local oscillation signal generator

 PLL implementation

 -Frequency divider implementation

o Driver AMP design

 -High frequency elimination part

o DUPLEXR design

o V-band waveguide microstrip converter design technology

Figure 1. 64-71 GHz Wireless Bridge BLOCK DIAGRAM

o Developed V-band, 64-71GHz 1.25Gbps Wireless Bridge device

-V-band applied to broadband wireless repeater in 64 ~ 71GHz millimeter wave band

-ASK modulation method

-Designed / manufactured to support ultra low latency and 1.25Gbps broadband

-Reduced bandwidth occupied by customer's key requirements, increased transmission speed

-This microwave device uses ASK modulation method

-Microwave device is a wired / wireless integrated transmission device. In general, wired transmission mm wave equipment based on light in transmission network for transmitting voice (PSTN) or various data (PSDN).

-It is possible to configure a mixed wired / wireless network using a single device, so there are many advantages in network management, equipment management, and economics.

-GUI method running on PC for the convenience of operator

1. Specification Definition Parameters Specifications Unit-a Unit-b Transmitter RF Frequency Range 65.2-67.4 GHz 68.6-70.8 GHz Bandwidth 2200 MHz LO Frequency 66.3 GHz 69.7 GHz Output power +17 dBm typ. RF VSWR 2.0: 1 typ. Receiver RF Frequency Range 61.25-63.25 GHz 57.75-59.75 GHz Bandwidth 2000 MHz Noise figure 9 dB typ. Sensitivity -49dBm @BER 10-12 RF VSWR 2.0: 1 typ. Common Modulation, Latency ASK, 20ns Data rate 1.25Gbps Full-Duplex Link margin -66 dB RF Port WR-15 Signal interface 850nm MMF-LC Fiber SFP Main power + 48Vdc

Fig. 2, SPF Transceiver Type

2. SFP for Gigabit Ethernet

2.1 SFP Transceiver

-Optical transceiver is a device that combines the functions of an optical transmitter and a receiver. A module that converts an electrical signal into an optical signal and an optical signal into an electrical signal in an optical communication device such as a router or a switch.

Figure 3. Optical transceiver conceptual diagram

The receiver consists of two pairs of photo detectors (PD), a bandpass filter (BPF) and a tunable laser source (TLS)

The received optical signal is divided in half into the baseband receiver and the RF band receiver.

-Since the baseband receiver is received by the conventional direct detection method, the transmitted signal can be used in the baseband

-A multi-carrier based transmission system capable of receiving frequency selective can receive desired subcarriers using BPF.

The RF band receiver can up-convert the input signal to a desired RF band using TLS, a light source that can change the wavelength.

When a light source with two different wavelengths is received at the PD, the received signal generates not only the baseband but also the beating component based on the difference between the two wavelengths.

Therefore, if the bandpass filter is used after the receiver, the desired subcarrier group can be received. At this time, by adjusting the wavelength of the TLS, it is possible to receive the received signal in the desired RF band.

Figure 4. Communication Connector

2.2 Fiber Optic type

 -Model type: ME1G

IO Terminal: 850nm MMF / LC (Default), 1310nm SMF / LC (Optional)

Figure 5. Digital Structure

General term for Modulator and Demodulator in wireless transmission system, the main function is to modulate and demodulate the signal to be sent (audio, multimedia data, etc.) into an analog signal suitable for transmission to the wireless space.

Figure 6. Modulator Block Diagram and Figure 7. Demodulator Block Diagram

- The information to be transmitted through the microwave transmission device is converted into digital data, processed through digital signal processing, sorted into a form that meets the transmission standard, and then input to the encoder of the modulator.

- In encoder, source coding and channel coding are performed. In mapper, input data is divided into symbols suitable for modulation method.

- Two symbols are created, in-phase (I) and quadrature-phase (Q).

- Digital Filter adjusts the band so that the modulated signal fits the designated channel band by pulse shaping and converts it into analog signal through Digital-to-Analog Converter (DAC).

- The generated signal is called a baseband signal, which is mixed by an intermediate frequency with a 90 degree phase difference to generate an IF band signal.

IF signal is properly amplified and transmitted to wireless transmitter

8. Modulator Functional Diagram

A) modulator

-The modulator basically receives digital data and generates an analog signal (IF) after modulation. The function structure and detailed functions are as follows.

- Input digital data of capacity to be transmitted in parallel structure of 19.44Mbps 병렬 8bit

- Receives a signal indicating the start position of a frame of data to be transmitted and processes the signal according to the transmission standard

- Compensation for errors that may occur due to spatial environment during transmission

- Design by extracting coefficients inverse to compensate group delay for the entire path of digital filter transmission and reception

- Direct communication using MCU (Main Control Unit) and local bus

- Generates I / Q baseband signals by 2-over sampling twice the sampling frequency

- Filter out the staircase analog signal passing through the D / A converter and remove the image component appearing at the sampling frequency.

9. Demodulator Function Configuration

B) demodulator

- AGC is used to keep average power of received signal constant

- It consists of an amplifier circuit using a transistor, a detection circuit using a schottky diode, and a control circuit that amplifies weak detection signals and controls the capacitance of a PIN diode.

- A circuit is configured to automatically compensate quadrature phases using the phase differences detected in the FPGA.

- Eliminate local and image components that occur in down-conversion

- Converts a single ended signal passed through the LPF to a differential signal resistant to common noise and passes it to the ADC

- The input I / Q baseband signal has a more periodicity by the square operation and passes through the resonator to remove the noise except the sampling frequency.

Figure 10. V-band Transceiver Block Diagram

4. ASK Transceiver Part

-Transmitter consists of UP Converter, Driver Amp, Power AMP

-Receiver consists of LNA, DOWN Converter, and Limiting Amplifier

The transmitter and receiver use the same antenna and use a diplexer to block out-of-band clutter

-Multiply frequency wave using LO PLDOR

-Isolation between transmission and reception depends on the characteristics of the Diplexer.

11. Frequency up-conversion unit

end. Frequency Up Converter

① Mixer is used to increase the frequency of the input signal (DC ~ 1,200MHz).

② If the signal size from LO is sufficient, conversion loss does not occur much.

3. Use BPF to remove the signals that appear after the mixer at the final output from the module. Diplexer is used by combining frequency up-conversion unit and down-conversion unit.

12. Frequency down converter

I. Frequency down converter

① The signal coming through the first stage BPF is converted into the BB signal through the mixer.

② Make DET pin to detect the magnitude of the input signal.

③ Use Limiting Amp before the final input stage so that the received signal does not exceed the limit even if the incoming value is saturated.

13. PLL generator

All. Frequency local oscillation signal generator

Local oscillation signal generator required for frequency up-change. The frequency requires 11.05 GHz and 11.6167 GHz. Use the PLL chip to lock the frequency. The reference frequency uses a 20 MHz TCXO. Use BPF to remove frequencies other than the LO frequency from the signal appearing at the VCO output.

PLL module configuration and Fig. 15. Phase Noise specification

The PLL is a phase locked loop and is a frequency circuit configured to keep the output signal frequency constant. The PLL module to be designed is a structure using a program counter and a high-speed prescaler designed for DTO among several PLL structures. In particular, the PLL IC includes a phase comparator, a program counter, and a prescaler. In general, the items considered in frequency synthesizer are Frequency Range and Phase Noise. Frequency Range and Phase Noise have a close relationship with each other and should be considered when designing a frequency synthesizer. The frequency range is determined by the VCO.

Design the PLL to satisfy the phase noise as shown in the table.

Figure 16. Emitter-coupled Swithch circuit

■ Frequency multiplication technology

-This method outputs a frequency multiplied by an integer N times the fundamental frequency with low frequency.

To generate a subband signal, a subband LO signal is generated by multiplying the frequency generated by the frequency generator. The filter is used to remove spurious and harmonic components generated by the multiplication module to satisfy the requirements, and is selected in consideration of the size reduction of the signal passing through the multiplication unit and insertion loss of the filter and the mixer.

In the design technique of frequency multiplier, emitter-coupled swithch circuit is implemented to multiply existing frequency in the first stage. In addition, hard limiting and proper power gain give the same characteristics as square waves.

------수식 1

------ Formula 1

)이

가 되므로 (수식1)에서 알 수 있듯이 입력 신호의 진폭변동에 대해 무관하고 각 고조파의 진폭이 입력신호에 대해

정도로 감소된다. 따라서 mitter-coupled swithch 회로는 효율이 높고 기수차의 충분한 고조파를 신호를 만들어 주파수 체배를 할수 있도록 한다. 또한 push-push connection은 (수식2)와 같이 2개의 트랜지스터를 사용하고 있는데 컬렉터를 함께 묶었기 때문에 push-push connection과는 달리 식에 같이 우수차의 고조파를 발생시키게 된다. 그러나 이들 고조파 성분의 진폭은 입력신호의 진폭에 비하여

정도로 감소한다. However, in the case of emitter-coupled swithch, the conduction angle (

)this

As can be seen from (Equation 1), the amplitude of each harmonic is independent of the input signal.

Is reduced to a degree. Thus, the mitter-coupled swithch circuit is highly efficient and generates enough harmonics of the aberration signal to allow frequency multiplication. In addition, push-push connection uses two transistors as shown in (Equation 2), and since the collectors are tied together, unlike the push-push connection, it generates harmonics of even difference. However, the amplitudes of these harmonic components are

Decrease to a degree.

Figure 17. Push-Push Connection Circuit

-----수식2

----- Formula 2

Figure 18. Drive AMP design

The RF output amplifies the GAIN in the drive amp due to loss.

-The following driver amp stage will be designed considering X-Band frequency.

Gain-The ratio of the magnitude of the input to the output.

Bandwidth-The frequency range that can be processed.

Efficiency-The ratio of power consumed to the output to the amount of power used for full amplification.

Linearity-The amount of signal distortion at the output relative to the input signal.

Noise-unwanted signal that is added unwantedly in the amplifying circuit.

Output dynamic range-The ratio of the smallest signal level useful to the output to the largest signal level.

Slew Rate-The maximum rate at which the signal at the output changes. (In time change).

Step response-characteristics such as rise time, settling time and overshoot.

-Noise is affected by the size of the signal. If the voltage is low, the noise is likely to occur during the amplification process. That is, the driver amp will be designed considering not only the circuit design but also the PCB design.

19. Filter;

(a) LPF (Low Pass Filter)

Only pass frequency components lower than the cut-off frequency

(b) BPF (Band Pass Filter)

-Pass only the forces within a specific frequency band as desired without attenuation;

(c) HPF (High Pass Filter)

-Pass only the frequency components higher than the cut-off frequency among the frequency components of the input signal, and stop as much as possible.

(d) BSF (Band Stop Filter, BRF-Band Reject Filter, Notch Filter: Bandstop Filter)

-Pass only the forces within a specific frequency band as desired without attenuation;

■ High Frequency Rejection

In general, when a signal passes through a multiplier, a large change loss and unwanted harmonics are generated, which requires a combination of an amplifier to compensate for the change loss and a filter to remove harmonics.

In addition, when the signal is amplified, unwanted harmonics are generated, and when these harmonics are applied to the multiplier, more unwanted harmonic signals are generated. Therefore, a high performance filter is required to remove harmonics from the signal applied to the multiplier.

Filters can be classified into four types according to their characteristics for passing a specific frequency band.

20. Power AMP unit design

hemp. Power AMP Design

The block of the PA module is a drive amplifier to secure enough input of the high output MMIC amplifier, a divider / combiner for distributing and synthesizing the input and output of the high output MMIC amplifier, a detector and monitoring port for monitoring the output power, and the output of the PA from the outside. Consists of a control port for controlling the power, a power supply for supplying power to each component of the PA module.

Figure 21. Power divider / synthesizer design

bar. Power Divider / Synthesizer Design

-When designing a power divider / combiner, it is always considered to maintain the same size and the same phase when dividing an input signal into multiple output signals.

-Since the Power Divider / Combiner is a reversible passive circuit, the Power Divider / Combiner has the same analysis as the Power Divider when designing the Power Combiner Power.

-In the PA design, the output of a single device (FET, TR, Diode) is limited by the basic heat dissipation problem and the difficulty of impedance matching due to the limitation, so to meet the requirements of the overall system, two or more stages are needed. Only combine device outputs to achieve desired output levels

-The two-dimensional power synthesizer divider that can be surface mounted is the branch-line, the Wilkinson Power Divider / Combiner, and the Lange Coupler. The synthesizer has high reliability, low insertion loss, and good bandwidth available output level.

22. Diplexer block diagram, FIG. 23. Frequency spectrum and FIG. 24. Diplexer configuration.

four. Duplexer Division

The figure below shows the V-band Radio frequency plan. In order to block out-of-band unwanted waves, the implementation of Diplexr with good isolation characteristics is important.

25. Waveguide Microstrip Stereo View

Ah. V-band waveguide microstrip converter design technology

  The figure below shows the transition stereogram. A transition is required when a signal exits to the WR15 output port. The transition characteristics should be good to send the output without loss as much as possible.

■ Microstrip Transmission Line

  ㅇ One of the flat transmission lines (strip line, microstrip line, slot line, etc.)

Figure 26. Microstrip Structure

■ Microstrip Structure

  ㅇ A dielectric is placed between two metal plates (microstrip, ground conductor), and the structure of electromagnetic waves propagates mainly in the dielectric.

    -A grounded transmission line with a ground conductor plate at the bottom of the dielectric plate and a thin conductor plate as a signal line on the dielectric plate.

27. Microstrip Features

■ Microstrip Features

  ㅇ Radio mode

    Not full TEM mode, but rather quasi-TEM mode

    . Most of the electromagnetic fields are in the dielectric plate, but some of them are also present in the upper air region.

ㅇ Easy to integrate with other devices

     -Used for transmission line inside RF integrated circuit

  ㅇ Easy to manufacture and easy to attach active elements

■ Microstrip Dispersion Relation Expression

  ㅇ Relational equation in which the wave number, phase velocity, and frequency change according to the characteristics of the medium

 -εe: Effective dielectric constant

28. MCU Module Part

Items that can be controlled in the GUI are as follows.

-Check Link Status

-Received Signal Strength Indication (RSSI) level threshold setting

-System temperature alarm setting

-Network Connection alarm setting.

-RSSI: Display Function by Detecting Input Power

-Check the system status after connecting to the board using the IP address of the interface board (Link Status, RSSI, etc.)

-Save after checking RSSI and temperature threshold setting

-Check whether the set values are correctly input after system reboot.

-In case of system trouble, trouble shooting proceeds based on the settings

[CPU]-Samsung S3C2440 Processor

[Memory]-32MByte SDRAM,-64MByte NAND Flash

Figure 29. DC / DC Block Diagram

car. DC / DC Converter Design

Only -48V powers the system, so power is supplied to the ASK Transceiver, Optic Transceiver Borad, and MCU Borad

-Implement the internal borad by receiving DC + 5V

-DC / DC total capacity is designed as below

BORAD Voltage (v) Capacity (A) Power Consumption ASK Transceiver Borad + 5V 3A 15 W Optic transceiver borad + 5V 1A 5 W MCU Borad + 5V 1A 5 W PLL Borad + 5V 1A 5 W

The above detailed description should not be construed as limiting in all respects but should be considered as illustrative. In addition, it will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit and essential features of the present invention. Therefore, the scope of the present invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included in the scope of the present invention.

Claims (1)

Using the micrometer wave band.

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