WO2011148939A1 - Circuit d'amplification, dispositif de communication sans fil, système de communication sans fil et unité radio éloignée - Google Patents

Circuit d'amplification, dispositif de communication sans fil, système de communication sans fil et unité radio éloignée Download PDF

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Publication number
WO2011148939A1
WO2011148939A1 PCT/JP2011/061866 JP2011061866W WO2011148939A1 WO 2011148939 A1 WO2011148939 A1 WO 2011148939A1 JP 2011061866 W JP2011061866 W JP 2011061866W WO 2011148939 A1 WO2011148939 A1 WO 2011148939A1
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WIPO (PCT)
Prior art keywords
signal
unit
amplifier
voltage
wireless communication
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PCT/JP2011/061866
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English (en)
Japanese (ja)
Inventor
正 荒木
修一 西村
勇男 桂
Original Assignee
住友電気工業株式会社
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Priority claimed from JP2010121633A external-priority patent/JP2011250164A/ja
Priority claimed from JP2010292965A external-priority patent/JP2012142718A/ja
Priority claimed from JP2010293483A external-priority patent/JP2012142756A/ja
Priority claimed from JP2011012014A external-priority patent/JP2012156633A/ja
Application filed by 住友電気工業株式会社 filed Critical 住友電気工業株式会社
Publication of WO2011148939A1 publication Critical patent/WO2011148939A1/fr

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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/20—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers
    • H03F3/24—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers of transmitter output stages
    • H03F3/245—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers of transmitter output stages with semiconductor devices only
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/02—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation
    • H03F1/0205—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation in transistor amplifiers
    • H03F1/0211—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation in transistor amplifiers with control of the supply voltage or current
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/30—Modifications of amplifiers to reduce influence of variations of temperature or supply voltage or other physical parameters
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/32—Modifications of amplifiers to reduce non-linear distortion
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/189—High-frequency amplifiers, e.g. radio frequency amplifiers
    • H03F3/19—High-frequency amplifiers, e.g. radio frequency amplifiers with semiconductor devices only
    • H03F3/193—High-frequency amplifiers, e.g. radio frequency amplifiers with semiconductor devices only with field-effect devices
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/02—Transmitters
    • H04B1/04—Circuits
    • H04B1/0475—Circuits with means for limiting noise, interference or distortion
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/102—A non-specified detector of a signal envelope being used in an amplifying circuit
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/447—Indexing scheme relating to amplifiers the amplifier being protected to temperature influence
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/451—Indexing scheme relating to amplifiers the amplifier being a radio frequency amplifier
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/468—Indexing scheme relating to amplifiers the temperature being sensed

Definitions

  • the present invention relates to an amplifier circuit, a wireless communication device, a wireless communication system, and a remote radio unit.
  • a high-frequency power amplifier (HPA: High Power Amplifier, hereinafter also simply referred to as an amplifier or HPA) has a maximum input signal range close to the maximum output power (saturated power) from the viewpoint of power efficiency. Used to be.
  • the linearity of the input / output characteristics decreases as it approaches the saturated power, causing distortion in the output signal.
  • Such distortion of the input / output characteristics appearing in the amplifier appears as unnecessary radiation in the frequency domain, that is, adjacent channel leakage power, which may affect the adjacent channel or may not obtain a desired output.
  • Non-Patent Document 1 A distortion compensation circuit that obtains a desired amplifier output by performing compensation processing has been proposed (see, for example, Non-Patent Document 1).
  • a configuration in which a baseband signal processing unit and a wireless communication unit are separated is increasing as a wireless communication system such as a wireless base station device.
  • the wireless communication unit is installed immediately below the antenna, and the baseband signal processing unit is installed at a position away from the wireless communication unit.
  • the baseband signal processing unit and the wireless communication unit are connected by a line using a transmission path such as an optical fiber.
  • the wireless communication unit is called a remote radio unit (RRU).
  • RRU remote radio unit
  • RRH remote radio head
  • a device having a baseband signal processing unit and other functions is called a baseband unit (BBU) (see, for example, Patent Document 1).
  • connection interface As a connection interface between the baseband unit and the remote radio head, standards such as CPRI (Common Public Radio Interface) and OBSAI (Open Base Station Standard Initial) have been established. In lines using these connection interfaces, in addition to a channel for baseband IQ signals, an Ethernet (registered trademark) channel can be logically set.
  • CPRI Common Public Radio Interface
  • OBSAI Open Base Station Standard Initial
  • RRH remote radio head
  • the base station body and the remote radio head are connected by an optical fiber cable, and the remote radio head is within a range of several tens of kilometers from the vicinity of the base station body. It can be installed in a place.
  • Patent Document 2 discloses the following configuration. That is, in an outdoor communication casing, a base for fixing each functional module of communication equipment therein, a front lid coupled to the base, and a plurality of integrally formed on the outer surface of the base and the front lid Cooling fins.
  • the inside of the front lid is processed and formed according to the height of the heat generating component of each functional module of the communication equipment so that the heat generating component in each functional module of the communication equipment is in direct contact.
  • the cooling fin is for cooling the heat generated by the heat-generating component of each functional module of the communication equipment using outside air.
  • CPRI Common Public Radio Interface
  • Non-Patent Document 2 (“CPRI Specification V4.1”, [online], 2009). February 18, see ⁇ http://www.cpri.info/downloads/CPRI_v_ 4_1_2009 -02 -18.pdf>)).
  • DFS Dynamic Frequency Selection
  • DCS Dynamic Channel Selection
  • DCA Dynamic channel Allocation
  • the signal level of a certain frequency is measured, and if the measured signal level is higher than a predetermined threshold, it is determined that the frequency is in use. .
  • the distortion of the input / output characteristics may be caused by the temperature change of the amplifier, the frequency of the input signal, and the aging deterioration in addition to the distortion caused by the characteristics of the amplifier itself.
  • Such distortion of the input / output characteristics due to the temperature change and the frequency of the input signal is likely to appear mainly as a decrease in saturation power, and the distortion level appears to be larger than the distortion due to the characteristics of the amplifier itself.
  • the distortion of the input / output characteristics due to the frequency of the input signal is due to the following causes. That is, the amplifier includes matching circuits on the input side and the output side.
  • the matching characteristics of these matching circuits vary depending on the frequency, it is difficult to make the matching characteristics uniform over a wide band. For this reason, for example, even if the matching characteristics are set so as to be favorable with reference to the center of the band, the matching characteristics may deteriorate near the band edge. For this reason, in the vicinity of the saturated power at the band edge, in addition to the deterioration of the distortion characteristic due to approaching the saturated power, the deterioration of the matching characteristic of the matching circuit is combined, and as a result, the saturated power appears as a large decrease. When such a large distortion occurs, the fluctuation of the power of the output signal with respect to the input power becomes large, and it becomes difficult to perform distortion compensation with the conventional distortion compensation circuit. For this reason, there has been a demand for a measure for suppressing distortion of input / output characteristics that appears greatly due to a decrease in saturation power.
  • the present invention has been made to solve the above-described ⁇ Problem 1>, and can suppress distortion of input / output characteristics that may occur in accordance with a temperature change, a frequency of an input signal, or the like. And a wireless communication apparatus using the same.
  • ⁇ Problem 2> Regarding ⁇ Background Art 2>, in the wireless communication system, when transmitting a data signal (transmission signal) to be wirelessly transmitted between the BBU and the RRU, LOS (Loss Of Signal) or , LOF (Los Of Frame) may occur in the transmission signal. When a lack of signal occurs in the transmission signal, it interferes with wireless communication. Therefore, it is necessary to detect the lack of signal and perform appropriate processing promptly.
  • the RRU usually uses a CDR (Clock Data Recovery) circuit having a function of recovering an operation clock synchronized with the BBU from a transmission signal transmitted from the BBU, and each device of the own apparatus using the recovered clock recovered by the CDR circuit. And a PLL for generating a supply clock for supplying the signal.
  • CDR Lock Data Recovery
  • the CDR circuit detects the timing synchronized with the BBU obtained from the transmission signal, and adjusts the reproduction clock so that the phase of this timing is synchronized with the phase of the supply clock generated by the PLL, thereby operating the BBU operation clock. It is configured to be able to supply a clock synchronized with the.
  • the CDR circuit cannot obtain the synchronization timing based on the reference transmission signal when the transmission signal completely disappears or the signal absence state continues for a certain period, and cannot maintain the synchronization state. In this case, a synchronization error (out of lock) with the supply clock occurs.
  • the RRU causes the CDR circuit to detect the occurrence of synchronization deviation (out of lock) between the synchronization timing and the supply clock, so that the transmission signal is not transmitted at all or the signal absence state continues for a certain period. Can be detected.
  • the RRU makes its own judgment and performs appropriate processing in order to quickly perform appropriate processing after the lack of signal is detected.
  • the present invention has been made in order to solve the above-described ⁇ Problem 2>, and a radio communication apparatus capable of appropriately detecting a lack of signal in a transmission signal and promptly performing appropriate processing, and the same are used.
  • An object is to provide a wireless communication system.
  • the remote radio head needs to operate in synchronization with the base station body. Therefore, the remote radio head generates a reference timing signal such as a reference clock based on some signal transmitted from the base station main body, for example. In order to generate such a timing signal, the remote radio head is provided with a PLL (Phase Locked Loop) circuit, for example.
  • PLL Phase Locked Loop
  • the PLL circuit becomes in an asynchronous state. Then, depending on the time constant of the PLL circuit, it may take time to return to the synchronous state, and the influence on communication may be increased.
  • Patent Document 1 and Non-Patent Document 1 do not disclose a configuration for solving such a problem.
  • the present invention has been made to solve the above-described ⁇ Problem 3>.
  • the object of the present invention is to quickly shift from an asynchronous state to a synchronous state in a configuration that synchronizes with the target device based on a signal from the target device. To provide a wireless communication apparatus capable of returning.
  • ⁇ Problem 4> Regarding ⁇ Background Technology 4>, as a wireless communication system such as a wireless base station device, a configuration in which a baseband signal unit and a high frequency unit are separated in recent years has been increasing.
  • the high frequency unit is installed directly below the antenna, and the baseband signal processing unit is installed at a position away from the high frequency unit.
  • the baseband signal processing unit and the high frequency unit are connected by a transmission line such as an optical fiber.
  • a high-frequency unit is called a remote radio unit (RRU).
  • RRU remote radio unit
  • RRH remote radio head
  • a device having a baseband signal processing unit and other functions is called a baseband unit (BBU).
  • CPRI, OBSAI, etc. have been established as standards for transmission lines that connect baseband units and remote radio heads with optical fibers or the like.
  • an Ethernet (registered trademark) channel can be logically set.
  • a baseband unit including a communication control unit and a baseband signal processing unit detects a signal level. After determining the power frequency, it is necessary to issue a frequency switching command to the remote radio unit one by one.
  • the remote radio unit that receives the frequency switching command switches the reception frequency to the frequency specified by the baseband unit, and detects and measures the reception level. Then, the remote radio unit reports the detected reception level to the baseband unit.
  • reception level is frequently performed at a plurality of frequencies. Therefore, between the baseband unit and the remote radio unit, reception frequency switching commands, reception signal level reports, and the like are frequently performed. As a result, there is a possibility that the processing load of the baseband unit becomes large or other communication on the transmission path is hindered.
  • the present invention has been made to solve the above-described ⁇ Problem 4>, and it is an object of the present invention to reduce the processing load of a baseband unit when performing signal level detection processing in order to check a free frequency. To do.
  • an amplifier circuit of the present invention includes an amplifier that amplifies power of an input signal, a power supply unit that applies a power supply voltage to the amplifier, and an input / output of the amplifier An acquisition unit that acquires factor information indicating a change in a factor that causes a change in characteristics, and a control unit that adjusts the power supply voltage based on the factor information acquired by the acquisition unit. Yes.
  • the control unit that adjusts the power supply voltage based on factor information indicating a change in the factor that causes a change in the input / output characteristics of the amplifier is provided, for example, a temperature change or an input signal
  • factor information indicating a change in the factor that causes a change in the input / output characteristics of the amplifier for example, a temperature change or an input signal
  • the power supply voltage can be adjusted in a direction in which the distortion is suppressed according to the change in the factor. it can.
  • distortion appearing in the input / output characteristics of the amplifier can be suppressed.
  • the amplifier circuit further includes a storage unit that stores a correspondence table in which the factor information is associated with information related to the adjustment of the signal power of the power supply voltage, and the control unit stores in the storage unit
  • the power supply voltage is adjusted based on information relating to the adjustment of the power supply voltage obtained by referring to the table.
  • the control unit can obtain information on the adjustment of the power supply voltage by referring to the correspondence table without obtaining a numerical value necessary for adjustment by particularly complicated calculation, and the input / output characteristics of the amplifier. It is possible to quickly adjust the power supply voltage in accordance with the change in the factor that causes the change.
  • an amplifier circuit includes an amplifier that amplifies the power of an input signal and changes in factors that cause a change in input / output characteristics of the amplifier.
  • An acquisition unit that acquires the factor information that is indicated; and a control unit that adjusts the signal power of the input signal based on the factor information acquired by the acquisition unit.
  • the control unit that adjusts the signal power of the input signal based on factor information indicating a change in the factor causing the change in the input / output characteristics of the amplifier is provided, for example, a temperature change Even if there is a possibility that a large distortion appears in the input / output characteristics of the amplifier according to changes in factors such as the frequency of the input signal and the frequency of the input signal, the input signal The signal power can be adjusted. As a result, distortion appearing in the input / output characteristics of the amplifier can be suppressed.
  • the amplifier circuit further includes a storage unit that stores a correspondence table in which the factor information and information related to adjustment of the signal power of the input signal are associated with each other, and the control unit stores in the storage unit It is preferable that the signal power of the input signal is adjusted based on information related to the adjustment of the signal power of the input signal obtained by referring to the table. In this case, the control unit can obtain information related to the adjustment of the signal power of the input signal by referring to the correspondence table without obtaining a numerical value necessary for adjustment by particularly complicated calculation. It is possible to quickly adjust the signal power of the input signal in accordance with a change in a factor that causes a change in the input / output characteristics.
  • an amplifier circuit includes an amplifier that amplifies the power of an input signal and a modulation within a predetermined voltage range according to the power of the input signal.
  • a power supply modulation unit for applying the power supply voltage to the amplifier, an acquisition unit for acquiring factor information indicating a change in a factor causing a change in input / output characteristics of the amplifier, and the factor information acquired by the acquisition unit
  • a control unit that adjusts the maximum value of the predetermined voltage range based on the above.
  • the control unit that adjusts the maximum value of the predetermined voltage range in the power supply voltage is provided based on the factor information indicating the change in the factor causing the change in the input / output characteristics of the amplifier. For example, even if there is a possibility that a large distortion appears in the input / output characteristics of the amplifier depending on factors such as a temperature change and an input signal frequency, the voltage is controlled in a direction in which the distortion is suppressed according to the change in the factor. The maximum value of the range can be adjusted. As a result, by applying a power supply voltage modulated according to the power of the input signal to the amplifier, it is possible to improve power efficiency and suppress distortion of input / output characteristics.
  • factors that cause a change in the input / output characteristics of the amplifier include the temperature of the amplifier, the frequency of the input signal, the usage period of the amplifier, and the humidity around the amplifier. , At least one of them is selected.
  • the present invention is a wireless communication apparatus including an amplifier circuit, the amplifier circuit amplifying power of an input signal; A power supply unit that applies a power supply voltage to the amplifier, an acquisition unit that acquires factor information indicating a change in a factor that causes a change in input / output characteristics of the amplifier, and the power source based on the factor information acquired by the acquisition unit And a control unit that adjusts the voltage.
  • the amplifier circuit includes the above-described control unit, for example, there is a possibility that a large distortion appears in the input / output characteristics of the amplifier depending on factors such as a temperature change and an input signal frequency. Even if it occurs, the power supply voltage can be adjusted in a direction in which the distortion is suppressed according to the change in the factor, and as a result, the distortion of the input / output characteristics can be suppressed.
  • the present invention is a wireless communication apparatus including an amplifier circuit, the amplifier circuit amplifying the power of an input signal; An acquisition unit that acquires factor information indicating a change in a factor that causes a change in input / output characteristics of the amplifier, and a control unit that adjusts the signal power of the input signal based on the factor information acquired by the acquisition unit; It is characterized by having.
  • the amplifier circuit includes the above-described control unit, for example, there is a possibility that a large distortion appears in the input / output characteristics of the amplifier depending on factors such as a temperature change and an input signal frequency. Even if it occurs, the signal power of the input signal can be adjusted in a direction in which the distortion is suppressed according to the change in the factor, and as a result, the distortion of the input / output characteristics can be suppressed.
  • the present invention is a wireless communication apparatus in which a transmission signal in which sections including known signals are periodically arranged is given from a baseband processing apparatus, It is characterized by comprising a determination unit for determining the presence or absence of a signal in the transmission signal based on the detection result of a known signal in the transmission signal.
  • the determination unit determines the presence or absence of signal in the transmission signal based on the detection result of the known signal periodically arranged in the transmission signal.
  • the presence or absence of a signal can be determined at regular intervals. As a result, even if the signal lack occurs intermittently in the transmission signal, it is possible to appropriately detect the signal lack in the transmission signal by periodically determining the presence or absence of the signal lack.
  • a signal acquisition unit that acquires a signal included in the section of the transmission signal, and a correlation value based on the acquisition signal acquired by the signal acquisition unit are included in the transmission signal
  • a correlation value calculation unit that is obtained as a detection result of the known signal, and the determination unit determines whether or not there is a signal lack in the transmission signal based on the correlation value obtained by the correlation value calculation unit.
  • the correlation value calculation unit obtains a correlation value between the reference signal for determining whether or not the known signal is included in the acquired signal and the acquired signal acquired by the signal acquiring unit.
  • This reference signal may be another acquired signal different from the acquired signal acquired by the signal acquiring unit, or may be a known signal stored in advance.
  • the acquisition signal and the other acquisition signal include one signal and the other signal includes a known signal.
  • a reference signal for determining whether or not the signal is present.
  • the wireless communication apparatus may have a function for compensating for distortion that occurs in the input / output characteristics of the amplifier. That is, in the wireless communication apparatus, an amplifier that receives the transmission signal as an input signal and outputs the amplified transmission signal as an output signal, and a distortion compensation unit that compensates for distortion occurring in input / output characteristics of the amplifier,
  • the signal acquisition unit acquires a signal included in the section of the input signal and a signal included in the section of the output signal, and supplies the signal to the correlation value calculation unit and the distortion compensation unit. It may be a thing.
  • the signal acquisition unit acquires the input signal and output signal of the amplifier necessary for the distortion compensation unit to perform distortion compensation of the amplifier, and the correlation value calculation unit calculates the correlation value using these input / output signals. Therefore, the determination unit and the distortion compensation unit can be used as a signal acquisition unit, and the apparatus scale can be reduced.
  • the correlation value calculation unit may obtain a correlation value using two acquired signals acquired from different sections. In this case, a high correlation value is obtained if the two acquired signals both contain a known signal, and a low correlation value is obtained if either or both do not contain a known signal (due to lack of signal). It is done. As described above, the correlation value calculation unit can obtain the correlation value as a detection result of the presence or absence of a known signal in the transmission signal.
  • the wireless communication apparatus further includes a storage unit for storing the known signal, and the correlation value calculation unit stores the acquired signal acquired by the signal acquisition unit and the storage unit in advance. A correlation value between the stored known signals may be obtained. In this case, if an acquisition signal is acquired from the section, a correlation value with a known signal stored in advance can be obtained, and the presence or absence of a signal in the transmission signal can be determined. As a result, the process related to determination is simplified.
  • the signal acquisition unit acquires a signal included in the section of the transmission signal at a predetermined time interval, and the correlation value is smaller than a predetermined first threshold value
  • the signal acquisition unit may further include means for performing a control to reduce a time interval for acquiring the acquisition signal.
  • the first threshold is clearly determined that the acquisition signal does not include a known signal. If it is set to a value at which it is possible to determine that there is a lack of signal in the transmission signal, if the determination unit determines that there is a lack of signal in the transmission signal, the time interval at which the means acquires the acquisition signal is reduced. Even if the signal lack occurs intermittently in the transmission signal, the presence or absence of the signal lack can be reliably determined.
  • the determination unit determines the presence / absence of a signal absence in the transmission signal based on the number of times that the correlation value is determined to be smaller than a predetermined second threshold value. May be. More specifically, when the correlation value is smaller than the second threshold, the determination unit obtains, as a frequency, the number of times that the correlation value is determined to be smaller than the second threshold during a past certain period, and the frequency In response to this, it is also possible to determine the degree of signal absence in the transmission signal.
  • the determination unit may It is possible to determine the frequency at which it is determined that the lack of signal has occurred, and based on this frequency, the lack of signal in the transmission signal can be determined as a degree. Further, by determining the lack of signal as a degree, it is possible to more suitably perform processing for the lack of signal.
  • the determination unit determines that the frequency is smaller than a predetermined threshold value (threshold value FTh1). It may be determined that there is no lack of signal in the transmission signal. Even if it is not recognized that the lack of signal of the transmission signal is intermittently generated, the lack of signal may occur. Therefore, since the frequency is smaller than the predetermined threshold value (threshold value FTh1), the lack of signal is present. If not, it is preferable that the determination unit further includes means for leaving a log for the determination. In this case, even if the frequency of signal loss is small, it is determined that a signal loss has occurred. Therefore, it is possible to perform preventive processing by leaving a log regarding this determination.
  • the baseband processing device A means for recording a warning and / or recording a log for this determination, and if it is determined that the signal is severely absent, stop transmission of the transmission signal and / or restart the device itself And means. In this case, it is possible to quickly perform a suitable process according to the degree of lack of the transmission signal based on the determination on the wireless communication apparatus side.
  • the determination unit has the frequency equal to or higher than the predetermined threshold (threshold value FTh1) and smaller than another predetermined threshold (threshold value FTh2) set to a value larger than the predetermined threshold value.
  • the baseband processing device may be configured to determine that the transmission signal has a slight signal lack. In this case, when the determination unit determines that the transmission signal has a slight signal lack, Can be notified of a warning and / or log about this determination.
  • the determination unit may be configured to determine that the transmission signal has a severe signal lack.
  • the determination unit determines that the transmission signal is severely lacking, it is possible to stop transmission of the transmission signal and / or restart the device itself.
  • the determination unit may determine that the transmission signal has no signal absence when the correlation value is greater than or equal to a predetermined third threshold value. preferable.
  • the correlation value since the correlation value may be a value close to the third threshold value and it may be determined that there is no signal lack, the correlation value is a value that can be determined that the preset transmission signal has no signal lack.
  • the determination unit determines that the threshold value is less than a fourth threshold value that is greater than or equal to the third threshold value that is greater than the third threshold value, further includes means for leaving a log regarding this determination. May be. In this case, even if it is determined that there is no lack of signal in the transmission signal, preventive processing can be performed by leaving a log regarding the determination.
  • the present invention provides a baseband processor and a transmission signal in which sections including known signals are periodically arranged from the baseband processor.
  • a wireless communication system wherein the wireless communication device determines whether or not there is a signal lack in the transmission signal based on a detection result of a known signal in the transmission signal. It is characterized by having. According to the wireless communication system having the above configuration, as described above, it is possible to appropriately detect the lack of signal in the transmission signal, and it is possible to quickly perform appropriate processing.
  • a wireless communication apparatus provides a timing signal generation unit for generating a reproduction timing signal based on received data received from a target apparatus And generating a first control voltage based on the reproduction timing signal generated by the timing signal generator, and supplying the first control voltage to the voltage controlled oscillator, A jitter suppressor for generating a reference timing signal having a frequency component obtained by attenuating a component equal to or higher than a predetermined frequency among the frequency components of the reproduction timing signal and synchronizing with the reproduction timing signal, and the timing signal
  • the first control voltage Warini comprises an oscillator control unit for supplying to the voltage controlled oscillator a second control voltage is a first voltage within a predetermined range.
  • the oscillator control unit measures the first control voltage, and determines that an abnormality has occurred when the first control voltage falls outside a second predetermined range. To do.
  • an abnormality in the reproduction timing signal can be detected with a simple configuration.
  • the oscillator control unit measures the first control voltage, and when the first control voltage exceeds a maximum value in the second predetermined range, the first control voltage is measured.
  • a voltage having a maximum value in one predetermined range is supplied to the voltage controlled oscillator as the second control voltage, and the first control voltage falls below a minimum value in the second predetermined range, A voltage having a minimum value in a predetermined range of 1 is supplied to the voltage controlled oscillator as the second control voltage.
  • the capacitor in the jitter suppression unit is greatly increased when the control voltage is switched. It is not necessary to discharge or store electricity, and the operation of the jitter suppression unit can be stabilized.
  • the first predetermined range and the second predetermined range coincide with each other.
  • each range can be defined by two voltages, so that the circuit configuration can be simplified.
  • the oscillator control unit includes a first comparator for comparing the first control voltage with a first threshold voltage, and a second comparator different from the first threshold voltage.
  • a second comparator for comparing a threshold voltage with the first control voltage, and based on the comparison result by the first comparator and the comparison result by the second comparator, the reproduction timing Detect signal anomalies.
  • the oscillator control unit further sets the first threshold voltage based on the comparison result by the first comparator and the comparison result by the second comparator.
  • the control voltage is output to the voltage controlled oscillator, the second threshold voltage is output to the voltage controlled oscillator as the second control voltage, or the first control voltage is output to the voltage controlled oscillator. Includes a switch for switching output.
  • control voltage can be switched with a simple configuration by selecting each voltage using a switch.
  • the wireless communication apparatus further includes a retiming unit for holding and outputting the received data in response to the reference timing signal generated by the jitter suppressing unit.
  • the reception characteristics in the wireless communication apparatus can be improved by retiming the reception data from the target apparatus using the reference timing signal in which jitter is suppressed.
  • the wireless communication device transmits and receives wireless signals in accordance with WiMAX (Worldwide Interoperability for Microwave Access) standards.
  • WiMAX Worldwide Interoperability for Microwave Access
  • the usefulness of the present invention can be utilized under the severe time constraints in the TDD scheme for exchanging data with a frame configuration.
  • the present invention includes a baseband unit and a remote radio unit connected to the baseband unit, the remote radio unit receiving A detection unit that detects a signal level; and a control unit that performs a process of detecting a signal level by the detection unit and a process of transmitting information on a detection result by the detection unit to the baseband unit.
  • the control unit is a wireless communication system that determines a frequency of a signal detected by the detection unit and performs control to switch a frequency of a signal detected by the detection unit to the determined frequency.
  • the processing load on the baseband unit can be reduced.
  • control unit performs a process of transmitting information indicating availability of each of a plurality of frequencies as the information related to the detection result by the detection unit.
  • the baseband unit does not need to determine whether or not each frequency is free, and the processing load on the baseband unit is reduced.
  • control unit performs a process of collecting information on detection results for signals having a plurality of frequencies and transmitting the information to the baseband unit.
  • the frequency with which the information related to the detection result is transmitted from the remote radio unit to the baseband unit can be lowered, and the processing load and communication load associated with the transmission can be reduced.
  • the control unit can specify the timing of the detection section in which the signal level is to be detected based on the frame timing of the baseband signal from the baseband unit. (4-5) Further, the control unit can also specify the timing of the detection section in which the signal level should be detected based on the timing of the radio frame received by the remote radio unit.
  • the remote radio unit preferably includes a plurality of receivers for receiving signals for wireless communication, and at least one of the plurality of receivers is also used for signal level detection. In this case, communication can be maintained by another receiver even when the signal level is detected. Further, a receiver for wireless communication can be used for signal level detection, and a receiver that is also used for signal level detection can be used for wireless communication when it is not necessary to detect the signal level.
  • the remote radio unit includes a receiver that outputs a signal value in a section in which the level of the received signal is detected to a value indicating no signal to the baseband unit side.
  • a receiver that outputs a signal value in a section in which the level of the received signal is detected to a value indicating no signal to the baseband unit side.
  • the signal in the section in which the level of the received signal was detected is not a signal that should be received in the original communication, the level of the received signal was detected by setting it to a value indicating no signal. It is possible to prevent the signal in the section from becoming noise. On the baseband unit side, it is not necessary to distinguish between a section in which the level of the received signal is detected and a section in which it is not.
  • the present invention from another viewpoint is a remote radio unit connected to the baseband unit for detecting the level of the received signal in order to solve the above ⁇ Problem 4>.
  • the remote radio unit is characterized in that the frequency of the signal detected by the detection unit is determined and control is performed to switch the frequency of the signal detected by the detection unit to the determined frequency.
  • FIG. 3 is a block diagram showing a configuration of an amplifier in Chapter 1. It is a figure which shows an example of the content of the table memorize
  • FIG. 12 is a block diagram showing a radio base station apparatus as an example of a radio communication system in Chapter 2.
  • FIG. It is a figure which shows the structure of the radio
  • 10 is a block diagram illustrating a configuration of a radio processing unit of RRU 3 in Chapter 2.
  • FIG. It is a block diagram which shows the structure of the transmission signal process part which concerns on 1st embodiment in 2nd chapter. It is a figure for demonstrating the aspect in which both signal acquisition parts in Chapter 2 acquire the signal contained in a preamble area as an acquisition signal based on a frame timing signal.
  • FIG. 5 shows the manner of the input signal and the output signal when LOF is generated in both the input signal and the output signal.
  • 10 is a flowchart illustrating a signal lack determination process of a transmission signal performed by a second determination unit in Chapter 2. It is a block diagram which shows the structure of the transmission signal process part which concerns on 2nd embodiment in 2nd chapter.
  • FIG. 5 is an overall configuration diagram of a radio base station apparatus in Chapter 4. It is a block diagram of the remote radio unit in Chapter 4. 14 is a flowchart of reception level measurement processing in Chapter 4; It is a figure which shows the reception level table in Chapter 4.
  • (A) shows an example of a radio frame configuration of a reception channel in the FDD scheme
  • (b) is a diagram showing an example of a radio frame configuration of a reception channel in the TDD scheme.
  • It is a frame hierarchy diagram of CPRI.
  • It is a figure which shows the offset of a CPRI frame and a radio
  • It is a figure which shows the transmission frame structure of OBSAI.
  • It is a block diagram of the remote radio unit which concerns on 2nd Embodiment in 4th chapter.
  • FIG. 1 is an example of a configuration diagram of a wireless communication system having a base station device BS as a wireless communication device and terminal devices MS1, MS2, and MS3 as wireless communication devices in Chapter 1.
  • This system is configured in conformity with a wireless communication system called “WiMAX (Worldwide Interoperability for Microwave Access)” defined in IEEE 802.16, for example, and includes a base station apparatus BS and terminal apparatuses MS1 to MS3. Is capable of wireless communication in conformity with the above regulations.
  • WiMAX Worldwide Interoperability for Microwave Access
  • Each of the base station apparatus BS and the terminal apparatuses MS1 to MS3 includes a receiver R for receiving a radio signal, a transmitter S for transmitting a radio signal, and a processing unit P for processing a transmission / reception signal. I have.
  • the transmitter S transmits a linear modulation signal and includes an amplifier circuit 1 that amplifies the linear modulation signal.
  • the receiver R receives a linear modulation signal and has an amplifier circuit 1 for receiving and amplifying the linear modulation signal. Since the basic configuration of the amplifier circuit 1 is the same for both the transmitter S and the receiver R, the amplifier circuit 1 of the transmitter S will be described below as an example.
  • FIG. 2 is a block diagram showing an amplifier circuit according to the first embodiment of the present invention in Chapter 1.
  • the amplifier circuit 1 includes an amplifier (HPA) 2 for amplifying the power of an input signal supplied from the processing unit P, and a power supply unit 3 for applying a power supply voltage (drain voltage) to the amplifier 2.
  • the antenna A is connected to the output terminal of the amplifier 2, and the output signal output from the amplifier 2 is transmitted from the antenna A as a transmission signal.
  • the amplifier circuit 1 includes a signal power adjusting unit 4 for adjusting the signal power of the input signal that is a digital signal, and a digital / analog conversion in a path until the input signal from the processing unit P is given to the amplifier 2.
  • the modulation unit 6 converts the frequency of the input signal based on the transmission frequency determined by the frequency determination unit 8.
  • the frequency determination unit 8 determines a transmission frequency within a predetermined use frequency band.
  • the frequency determination unit 8 applies a high-frequency signal to the modulation unit 6 via the oscillator 9 so as to convert the input signal to the determined transmission frequency, and performs frequency conversion.
  • the frequency determination unit 8 is connected to the control unit 10 described later, and outputs frequency information indicating the determined transmission frequency to the control unit 10.
  • the frequency band of a transmission signal is defined in the range of 2496 to 2690 MHz. In practice, this frequency band is divided and a range of several tens of MHz is allocated as a use frequency band for each operator. It is done.
  • the frequency determination unit 8 is configured to set a use frequency band with a predetermined bandwidth including at least a part of the range defined by the WiMAX and to determine a transmission frequency therein. Yes.
  • the amplifier circuit 1 includes a control unit 10 for controlling the power supply unit 3 and the signal power adjustment unit 4.
  • the control unit 10 has a function of adjusting the power supply voltage supplied to the amplifier 2 and the signal power of the input signal by controlling the power supply unit 3 and the signal power adjustment unit 4. Further, the control unit 10 is connected to the frequency determination unit 8 as described above, and is further connected to a temperature sensor 11 provided in the vicinity of the amplifier 2.
  • FIG. 3 is a block diagram showing the configuration of the amplifier 2 in Chapter 1.
  • the amplifier 2 of this embodiment includes an FET 2a, an input matching circuit 2b connected to the gate side, and an output matching circuit 2c connected to the drain side.
  • the input matching circuit 2b and the output matching circuit 2c have a function for impedance matching between the input signal input to the amplifier 2 and the transmission signal output from the amplifier 2.
  • the temperature sensor 11 is arranged in the vicinity of the amplifier 2 as shown in FIG. 3 and detects the temperature of the amplifier 2 as a whole.
  • the temperature sensor 11 is composed of a thermistor or the like, detects the temperature of the amplifier 2 as a whole that changes due to heat generated by the FET 2a, etc., and outputs temperature information indicating the detected temperature to the control unit 10 as a change in electrical resistance. To do.
  • the control unit 10 outputs the frequency information from the frequency determination unit 8 and the temperature information from the temperature sensor 11.
  • the transmission frequency indicated by the information output to the control unit 10 and the detected temperature of the amplifier 2 cause changes in the input / output characteristics of the amplifier 2. That is, when the transmission frequency of the input signal is changed, the matching characteristics of the input matching circuit 2b and the output matching circuit 2c are deteriorated as described in the conventional example, and saturation is caused by causing distortion of the input / output characteristics of the amplifier 2. May reduce power. That is, a change in the transmission frequency within the range of the use frequency band becomes a factor that causes a change in the input / output characteristics of the amplifier 2.
  • the detected temperature of the amplifier 2 is also the same, and the amplification characteristic of the FET 2a changes according to the change in temperature. Therefore, the temperature change of the amplifier 2 causes a change in the input / output characteristics of the amplifier 2. .
  • the frequency information indicating the transmission frequency and the temperature information indicating the detected temperature of the amplifier 2 are factor information indicating changes in factors that cause a change in the input / output characteristics of the amplifier 2.
  • 11 constitutes an acquisition unit for acquiring factor information.
  • the control unit 10 adjusts the power supply voltage supplied to the amplifier 2 and the signal power of the input signal based on frequency information and temperature information as factor information output from the frequency determination unit 8 and the temperature sensor 11. Specifically, when the frequency information and the temperature information are given, the control unit 10 refers to the table stored in the storage unit 12 connected to the control unit 10 and the transmission frequency and the detected temperature grasped from each information. Based on the above, an adjustment value for performing the adjustment is acquired.
  • the storage unit 12 includes a first table in which the detected temperature detected by the temperature sensor 11 as the temperature of the amplifier 2 and the adjustment value of the power supply voltage, the transmission frequency obtained from the frequency determination unit 8, and the power supply voltage A second table in which adjustment values are associated is stored.
  • FIG. 4 is a diagram showing an example of the contents of the table stored in the storage unit 12 in Chapter 1, where (a) shows the first table and (b) shows the second table.
  • the detected temperature and the voltage adjustment value ⁇ V Dt indicating the adjustment value based on the rated voltage value of the amplifier 2 at the corresponding detected temperature are registered in the first table in association with each other. ing. Further, as shown in FIG.
  • the transmission frequency and the voltage adjustment value ⁇ V Df at the corresponding transmission frequency are registered in the second table in association with each other.
  • the voltage adjustment values ⁇ V Dt and ⁇ V Df as information relating to the adjustment registered in these tables are obtained by verifying and grasping the input / output characteristics of the amplifier 2 with respect to changes in the transmission frequency and the detected temperature in advance. Based on this, a value that can suppress the distortion appearing in the input / output characteristics as much as possible is set.
  • the storage unit 12 also stores the rated voltage value of the amplifier 2, and the control unit 10 obtains the rated voltage value of the amplifier 2, and is grasped from the frequency information and the temperature information with reference to both tables. Voltage adjustment values ⁇ V Dt and ⁇ V Df corresponding to the transmission frequency and the detected temperature are acquired. Then, the control unit 10 uses the value obtained by adding both voltage adjustment values ⁇ V Dt and ⁇ V Df to the rated voltage value as a power supply voltage, and controls the power supply unit 3 so that the power supply voltage is applied to the amplifier 2.
  • the voltage adjustment value ⁇ V Dt in FIG. 4A increases the power supply voltage as the temperature increases. As a result, a decrease in saturation power is suppressed, and distortion that occurs in the input / output characteristics is suppressed.
  • the transmission frequency is set so that the characteristics of the matching circuit and the like are good at the center frequency in the use frequency band set in the amplifier circuit 1, the transmission frequency becomes saturated as it approaches the band edge. The power is reduced. Therefore, in this case, assuming that the use frequency band is set to 2500 to 2700 MHz, as shown in FIG. 4B, the power supply voltage is increased as the end of the use frequency band is approached.
  • the voltage adjustment value ⁇ V Df is set. As a result, it is possible to suppress a decrease in saturation power at the band edge and to suppress distortion that occurs in the input / output characteristics.
  • the storage unit 12 stores a third table in which the detected temperature and the signal power adjustment value of the input signal are associated, and a fourth table in which the transmission frequency and the signal power adjustment value of the input signal are associated. is doing.
  • FIG. 5 is a diagram showing an example of the contents of the table stored in the storage unit 12 in Chapter 1, where (a) shows the third table and (b) shows the fourth table.
  • a signal power adjustment [Delta] P t is an adjustment value of the signal power of the input signal at a corresponding sensed temperature are registered in association. Further, as shown in FIG.
  • the fourth table registers the transmission frequency and the signal power adjustment value ⁇ P f at the corresponding transmission frequency in association with each other.
  • the signal power adjustment values ⁇ P t and ⁇ P f as information relating to the adjustments registered in both tables, the input / output characteristics of the amplifier 2 with respect to changes in the transmission frequency and the detected temperature are verified and grasped in advance. Based on the result, the distortion that appears in the input / output characteristics is set to be suppressed as much as possible.
  • the control unit 10 refers to both tables and acquires the signal power adjustment values ⁇ P t and ⁇ P f corresponding to the transmission frequency and the detected temperature grasped from the frequency information and the temperature information. Then, the control unit 10 sets a value obtained by adding both the signal power adjustment values ⁇ P t and ⁇ P f as an adjustment value for causing the signal power adjustment unit 4 to perform adjustment, and adjusts the input signal based on the adjustment value.
  • the signal power adjustment unit 4 is controlled.
  • the signal power adjustment value ⁇ P t in FIG. 5A indicates the signal power of the input signal as the temperature increases.
  • the transmission frequency is set so that the characteristics of the matching circuit and the like are good at the center frequency in the use frequency band set in the amplifier circuit 1
  • the transmission frequency is greatly distorted as it approaches the band edge. May appear.
  • the use frequency band is set to 2500 to 2700 Hz
  • the signal power of the input signal decreases as the use frequency band approaches the band end as shown in FIG. 5B.
  • the voltage adjustment value ⁇ V Df is set so that As a result, it is possible to avoid the use of a region that may cause significant distortion, and to suppress distortion that occurs in input / output characteristics.
  • a circuit element for example, can be configured by software by a DSP.
  • the digital circuit element indicates the presence of a functional element, and each element does not necessarily have to be separated and independent.
  • the power supply voltage based on the frequency information and temperature information indicating changes in factors (transmission frequency and temperature of the amplifier 2) that cause changes in the input / output characteristics of the amplifier 2, Since the control unit 10 that adjusts the signal power of the input signal is provided, even if there is a possibility that a large distortion appears in the input / output characteristics of the amplifier according to the change in the transmission frequency or the temperature of the amplifier 2, In accordance with the change, the power supply voltage and the signal power of the input signal can be adjusted in a direction in which distortion is suppressed. As a result, distortion appearing in the input / output characteristics of the amplifier 2 can be suppressed.
  • the first and second tables that associate the detected temperature and transmission frequency with the adjustment value of the power supply voltage, and the detected temperature and transmission frequency, and the signal power adjustment value of the transmission signal are obtained.
  • the storage unit 12 stores the associated third and fourth tables, and the control unit 10 inputs the power supply voltage and the input based on the voltage adjustment value and the signal power adjustment value obtained by referring to these tables.
  • the signal power of the signal was adjusted.
  • the control part 10 acquires the information regarding adjustment of a power supply voltage and the signal power of an input signal by referring to a correspondence table, without calculating
  • the power supply voltage and the power of the input signal can be quickly adjusted in accordance with changes in factors that cause changes in the input / output characteristics of the amplifier 2.
  • FIG. 6 is a block diagram showing an amplifier circuit according to the second embodiment of the present invention in Chapter 1.
  • the difference between the present embodiment and the first embodiment is that, instead of the power supply unit 3, a power supply modulation unit having an envelope tracking function for applying to the amplifier 2 a power supply voltage modulated according to the envelope signal of the input signal 13. Since other points are the same as those in the first embodiment, description thereof is omitted.
  • the power supply modulation unit 13 detects the input signal and extracts an envelope signal, and a voltage control unit that applies power-voltage conversion and D / A conversion to the extracted envelope signal and applies a power supply voltage to the amplifier 2 13b.
  • the voltage control unit 13b modulates the power supply voltage corresponding to the envelope signal within a predetermined voltage range and applies the modulated voltage to the amplifier 2.
  • the voltage control unit 13b increases power efficiency by suppressing the power supply voltage when the power of the envelope signal is relatively low and controlling the power supply voltage to be increased accordingly when the power of the envelope signal is relatively high.
  • the power supply voltage is controlled by a so-called envelope tracking method.
  • the control unit 10 adjusts the signal power of the input signal based on the frequency information and temperature information output from the frequency determination unit 8 and the temperature sensor 11, and adjusts the maximum value (maximum voltage value) in a predetermined voltage range. It has a function to do.
  • the control unit 10 refers to the above-described table stored in the storage unit 12 connected to the control unit 10 and based on the transmission frequency and the detected temperature grasped from each information. To obtain an adjustment value for adjustment.
  • the control unit 10 adjusts the maximum voltage value in a predetermined voltage range based on the acquired adjustment value.
  • the amplifier 2 is based on frequency information and temperature information indicating changes in factors (transmission frequency and temperature of the amplifier 2) that cause changes in the input / output characteristics of the amplifier 2.
  • a control unit 10 that adjusts the maximum voltage value in a predetermined voltage range in the power supply voltage applied to the power supply voltage, so that the input / output characteristics of the amplifier 2 are greatly distorted in accordance with changes in the transmission frequency and the temperature of the amplifier 2. Even if the possibility of appearing occurs, the maximum voltage value can be adjusted in a direction in which distortion is suppressed in accordance with the change. As a result, the distortion of the input / output characteristics can be suppressed while improving the power efficiency by the envelope tracking.
  • control unit 10 adjusts the power supply voltage (maximum value) by controlling the power supply unit 3 (power supply modulation unit 13), and controls the signal power adjustment unit 4 to control the input signal.
  • the signal power is adjusted, but it may be configured to adjust only one of the power supply voltage or the signal power of the input signal.
  • the case where the signal power adjustment unit 4 that processes the input signal in the digital signal region is used to adjust the signal power of the input signal is exemplified.
  • a variable attenuator or a variable gain amplifier may be used to adjust the signal power of the input signal in the analog signal region.
  • FIG. 2 and FIG. 6 the analog signal region between the modulation unit 6 and the preamplifier 7 or between the preamplifier 7 and the amplifier 2.
  • a variable attenuator can be arranged.
  • the variable gain amplifier can be arranged between the modulation unit 6 and the amplifier 7 in place of the preamplifier 7 in FIGS.
  • the control unit 10 performs control based on the transmission frequency of the input signal and the temperature of the amplifier 2 as factor information indicating a change in the factor that causes a change in the input / output characteristics of the amplifier 2.
  • factor information indicating a change in the factor that causes a change in the input / output characteristics of the amplifier 2.
  • the use elapsed time of the amplifier 2, the humidity around the amplifier 2, etc. can be used, for example. This is because the amplifier 2 deteriorates over time due to its use, and a decrease in saturation power occurs.
  • a timer or the like that integrates the operation time of the amplifier 2 is provided, and the usage elapsed period of the amplifier 2 can be acquired by this timer.
  • the humidity around the amplifier 2 can be obtained by disposing a humidity sensor that measures the humidity in the vicinity of the amplifier 2 in the same manner as the temperature sensor 11 of the above embodiment.
  • the factor information at least one of the transmission frequency of the input signal, the temperature of the amplifier 2, the elapsed usage period of the amplifier 2, and the humidity around the amplifier 2 is acquired and used. Control may be performed, or control may be performed by selecting any one of these factor information.
  • the present invention is applied to a wireless communication system (base station device, terminal device) compliant with WiMAX, but the present invention is not limited to this, and LTE (Long Termination Evolution)
  • the present invention can be applied to communication systems using other broadband.
  • FIG. 7 is a block diagram showing a radio base station apparatus 1 as an example of a radio communication system in Chapter 2.
  • the wireless base station device 1 is a device to which a terminal device such as a mobile phone is wirelessly connected.
  • the radio base station apparatus 1 is a system including a baseband unit (hereinafter sometimes simply referred to as “BBU”) 2 and a remote radio unit (hereinafter also simply referred to as “RRU”) 3. is there.
  • BBU baseband unit
  • RRU remote radio unit
  • this radio base station apparatus 1 is configured to perform radio communication conforming to WiMAX, for example.
  • FIG. 8 is a diagram illustrating the structure of a WiMAX radio frame.
  • a plurality of radio frames are arranged side by side in the time direction.
  • One radio frame is configured to include a downlink subframe DL (downlink transmission signal allocation area) and an uplink subframe UL (uplink transmission signal allocation area) arranged side by side in the time direction.
  • It is a communication system that performs duplexing of transmission and reception by a division duplex method. Note that the length of one radio frame is 5 msec.
  • the downlink subframe DL includes a preamble signal (Preamble) that is a known signal at the head.
  • the preamble signal is a signal that is used for synchronization between the base station apparatus and the terminal apparatus, and that the terminal apparatus measures the signal strength from the base station apparatus.
  • a plurality of patterns having different codes and the like are prepared for the preamble signal.
  • the transmission signal transmitted by the radio base station apparatus 1 includes a period including a preamble signal that is a known signal. Are periodically arranged.
  • the preamble signal is a known signal defined in advance, and the time width of the preamble section including the preamble signal is also set to a predetermined constant value.
  • BBU 2 and RRU 3 are connected by a line using a transmission line such as optical fiber 4.
  • An electric cable may be adopted as the transmission line instead of the optical fiber.
  • RRU 3 not only one RRU 3 but also a plurality of RRUs 3 may be connected to one BBU 2.
  • OBSAI is adopted as a connection interface between BBU2 and RRU3.
  • CPRI Connection interfaces
  • BBU2 is called REC (Radio Equipment Control)
  • RRU3 is called RE (Radio Equipment Control).
  • the BBU 2 is a baseband signal that processes a baseband signal passed between the upper network I / F 21 for connecting to the upper network of the radio base station apparatus 1, the communication control unit 22 that controls communication, and the RRU 3.
  • the unit 23 and the optical I / F 24 are provided.
  • the RRU 3 includes an optical I / F 31 and a wireless processing unit 32 that processes a high-frequency wireless signal transmitted and received from the antenna 33.
  • the optical I / F 24 and the optical I / F 31 are connection interface units compliant with OBSAI, and have a function of performing transmission control processing compliant with OBSAI.
  • the optical I / F 24 and the optical I / F 31 together with the optical fiber 4 form a line connecting the BBU 2 and the RRU 3.
  • FIG. 9 is a block diagram illustrating a configuration of the radio processing unit 32 of the RRU 3 in Chapter 2.
  • the wireless processing unit 32 has one receiver 5 and one transmitter 6.
  • the receiver 5 and the transmitter 6 are connected to the antenna 33 via the duplexer 7.
  • the receiver 5 includes a reception signal processing unit 5a, an ADC (AD converter) 5b, a filter 5c, a mixer 5d, and a reception amplifier 5e.
  • the reception signal received by the antenna 33 is given to the reception amplifier 5e via the duplexer 7.
  • the reception amplifier 5e amplifies the reception signal and outputs it to the mixer 5d.
  • An oscillator (not shown) is connected to the mixer 5d, and the mixer 5d converts the frequency of the received signal into a baseband frequency using a signal oscillated by the oscillator.
  • the received signal converted to the baseband frequency is given to the ADC 5b through the filter 5c formed of a bandpass filter or the like.
  • the ADC 5b converts the received signal, which is an analog signal, into a digital signal and outputs the digital signal to the received signal processing unit 5a.
  • the reception signal processing unit 5a performs quadrature demodulation on the digitally converted reception signal, and transmits the demodulated reception signal (IQ signal) to the BBU 2 via the optical I / F 31.
  • the transmitter 6 includes a transmission signal processing unit 6a, a DAC (DA converter) 6b, a filter 6c, a mixer 6d, and a transmission amplifier 6e. Further, the transmitter 6 is configured to feed back the output signal of the transmission amplifier 6e to the transmission signal processing unit 6a, in addition to the coupler 6f connected to the subsequent stage of the transmission amplifier 6e, the mixer 6g, the filter 6h, and the ADC. (AD converter) 6i is provided.
  • the transmission signal processing unit 6a is connected to the optical I / F 31, processes a data signal (transmission signal) to be wirelessly transmitted, which is transmitted from the BBU 2 as a digital signal (IQ signal), and outputs the data signal to the DAC 6b. . Further, the transmission signal processing unit 6a has a function of compensating for distortion of the transmission amplifier 6e and a function of determining whether there is a lack of data signals (details will be described later).
  • the DAC 6b converts a transmission signal, which is a digital signal, into an analog signal, and outputs the analog signal to the mixer 6d via a filter 6c including a band pass filter or the like.
  • An oscillator (not shown) is connected to the mixer 6d.
  • the mixer 6d converts a transmission signal into a high-frequency signal using a signal oscillated by the oscillator, and outputs the signal to the transmission amplifier 6e.
  • the transmission amplifier 6e receives the transmission signal converted into the high-frequency signal as an input signal and outputs the amplified transmission signal as an output signal.
  • An antenna 33 is connected to the output terminal of the transmission amplifier 6e via the duplexer 7, and an output signal (transmission signal) output from the transmission amplifier 6e is transmitted from the antenna 33.
  • a transmission signal input to the transmission amplifier 6e is also referred to as an input signal
  • an amplified transmission signal output from the output terminal of the transmission amplifier 6e and acquired as a feedback signal is also referred to as an output signal.
  • the coupler 6f connected to the latter stage of the output terminal of the transmission amplifier 6e acquires the output signal (amplified transmission signal) output from the transmission amplifier 6e and supplies it to the mixer 6g.
  • the mixer 6g, the filter 6h, and the ADC 6i have substantially the same functions as the mixer 5d, the filter 5c, and the ADC 5b of the receiver 5, respectively, and the output signal obtained by the coupler 6f is converted into a digital signal. Then, it is given to the transmission signal processing unit 6a as a feedback signal.
  • the wireless processing unit 32 includes a control unit 8 that comprehensively controls the operation of the RRU 3 and the like.
  • the control unit 8 receives from the transmission signal processing unit 6a the notification of the determination result regarding the determination of the presence / absence of the signal and the detection notification indicating that the occurrence of the synchronization shift with the BBU 2 is detected. For example, control related to processing performed by the RRU 3 such as transmission stop of the transmission signal and restart of the RRU 3 is performed.
  • FIG. 10 is a block diagram showing the configuration of the transmission signal processing unit 6a according to the first embodiment in Chapter 2.
  • the transmission signal processing unit 6a includes a modulation processing unit 40 that performs processing such as orthogonal modulation of the transmission signal provided from the BBU 2 via the optical I / F 31, and input / output characteristics of the transmission amplifier 6e with respect to the modulated transmission signal.
  • a distortion compensation unit 41 that performs distortion compensation generated in the above.
  • the distortion compensation unit 41 is a model that represents input / output characteristics using an input signal (amplified transmission signal) input to the transmission amplifier 6e and an output signal (amplified transmission signal) output from the transmission amplifier 6e. And distortion compensation is performed on the modulated transmission signal based on this estimation model.
  • the distortion compensation unit 41 outputs the transmission signal after the distortion compensation to the DAC 6b.
  • the transmission signal processing unit 6a includes an input signal buffer unit 42 that acquires and stores the input signal in order to acquire the input signal and the output signal used by the distortion compensation unit 40 to perform distortion compensation, and the output signal. And an output signal buffer unit 43 that acquires and accumulates.
  • the input signal buffer unit 42 is connected between the distortion compensation unit 41 and the DAC 6b, and acquires and accumulates input signals input to the transmission amplifier 6e via the DAC 6b and the like.
  • the output signal buffer unit 43 is connected to the ADC 6i that converts the output signal output from the transmission amplifier 6e fed back via the coupler 6f into a digital signal, and acquires and accumulates the output signal.
  • Signal acquisition units 44 and 45 are individually connected to the input signal buffer unit 42 and the output signal buffer unit 43.
  • Both signal acquisition units 44 and 45 acquire, as acquisition signals, signals included in the preamble section (see FIG. 8) from the input signals and output signals accumulated in the input signal buffer unit 42 and the output signal buffer unit 43. Both signal acquisition units 44 and 45 acquire a signal (acquisition signal) based on the frame timing signal given from the frame timing acquisition unit 46.
  • the frame timing signal is a signal indicating the frame timing of the radio frame of the transmission signal, and is generated by the BBU2.
  • the frame timing acquisition unit 46 acquires a frame timing signal from the BBU 2 and gives it to both signal acquisition units 44 and 45.
  • FIG. 11 is a diagram for explaining a mode in which both signal acquisition units 44 and 45 acquire a signal included in a preamble section as an acquisition signal based on the frame timing signal in Chapter 2.
  • the horizontal axis indicates time, and the downlink transmission signal, the frame timing signal, and the signal acquisition timing transmitted from the radio base station apparatus 1 are sequentially associated with the time axis from the top.
  • the frame timing signal is a signal transmitted at either the H level or the L level lower than the H level, and from the H level to the L level at the start timing of each radio frame. Or from L level to H level. Accordingly, the frame timing signal indicates the start timing of each radio frame according to the timing at which the level is switched.
  • the preamble section is set to a predetermined time width predetermined from the beginning of the radio frame. Therefore, if the timing of the start of each radio frame can be recognized, the preamble section can be specified. Therefore, both signal acquisition units 44 and 45 obtain the timing TE advanced by the preamble section, which is the period including the preamble signal, from the timing TS at the beginning of each radio frame based on the frame timing signal, Specify the preamble section. Both signal acquisition units 44 and 45 acquire signals included between the timings TE from the timings TS among the input signals and output signals accumulated in the input signal buffer unit 42 and the output signal buffer unit 43, A signal included in the preamble section can be acquired as an acquisition signal.
  • both signal acquisition units 44 and 45 can acquire acquisition signals included in all preamble sections. However, when performing distortion compensation and determination of the absence or absence of signals, which will be described later, In some cases, it is less necessary to acquire a signal included in the preamble section. Therefore, both signal acquisition units 44 and 45 of this embodiment acquire signals after a predetermined time. Specifically, the time interval at which both signal acquisition units 44 and 45 acquire the acquisition signal is set to two types of time intervals, a relatively short interval D S and a longer interval D L.
  • the control unit 8 sets the time interval for acquiring the acquisition signals of both the signal acquisition units 44 and 45. Here, a case where two types of time intervals can be set is shown, but the time intervals may be set in more stages.
  • both signal acquisition parts 44 and 45 acquire an acquisition signal, correcting the delay error.
  • both signal acquisition units 44 and 45 output the acquired acquisition signals to the correlation value calculation unit 47.
  • the correlation value calculation unit 47 is similar between an acquisition signal from the signal acquisition unit 44 (hereinafter also referred to as a first acquisition signal) and an acquisition signal from the signal acquisition unit 45 (hereinafter also referred to as a second acquisition signal). A correlation value indicating the degree of sex is obtained.
  • the correlation value calculation unit 47 calculates the correlation value as a value in the range of “0” to “1”.
  • the correlation value calculation unit 47 is closer to “1” as the degree of similarity between the first acquisition signal and the second acquisition signal is higher, and is set to “0” as the degree of similarity is lower.
  • the correlation value is obtained so that the values are close. That is, the correlation value indicates that the closer to “1”, the higher the correlation between both signals, and the closer to “0”, the lower the correlation between both signals.
  • the correlation value calculation unit 47 gives the obtained correlation value to the first determination unit 48 and the second determination unit 49.
  • the first determination unit 48 determines whether or not to perform distortion compensation by the distortion compensation unit 41 based on the correlation value given from the correlation value calculation unit 47.
  • the first determination unit 48 is configured to determine, for example, that the correlation value is “0.9” or more and that distortion compensation is performed. If the correlation value is “0.9” or more, the first determination unit 48 gives the first and second acquired signals to the distortion compensation unit 41 and causes the distortion compensation unit 41 to perform distortion compensation.
  • the second determination unit 49 acquires the correlation value given from the correlation value calculation unit 47 as the detection result of the known signal in the transmission signal, and determines the presence / absence of a signal lack in the transmission signal based on this.
  • FIG. 12 is a diagram for explaining the relationship between the lack of signal that occurs in the transmission signal and the correlation value between the first acquisition signal and the second acquisition signal in Chapter 2.
  • the preamble signal is included in the preamble section of the input signal and the output signal. , 45 both include a preamble signal, and the degree of similarity between them is high. Therefore, the correlation value obtained by the correlation value calculation unit 47 is a high value.
  • the second acquisition signal does not include the preamble signal but includes the noise component. Become. Therefore, the degree of similarity between the first acquisition signal that includes the preamble signal and the second acquisition signal that does not include the preamble signal is low, and the correlation value is low.
  • both the acquired signals do not include the preamble signal but include a noise component. Since the noise components are uncorrelated, the correlation value is a low value in this case as well.
  • the correlation value calculated by the correlation value calculation unit 47 from both acquired signals is a high value if the preamble signal is included in the transmission signal, and is a low value if it is not included. That is, the correlation value is obtained as a detection result of the preamble signal in the transmission signal.
  • FIG. 12 shows a case where LOF occurs, that is, a case where a signal lack occurs in units of radio frames. Based on the correlation value, it is determined whether or not a preamble signal is included in the acquired signal acquired from the preamble section. If detected, it is possible to determine the lack of signal in units of radio frames.
  • the transmission signal includes a preamble section including a preamble signal in each radio frame, so that a fixed period is obtained. Arranged at intervals. Therefore, if the acquisition signal acquired from the preamble section includes a preamble signal, at least in this preamble section, no signal is absent, and the signals before and after this preamble section are normal and there is no signal lack. It can be estimated that it is a transmission signal.
  • the second determination unit 49 of the present invention determines the presence or absence of a signal in the transmission signal based on the correlation value between the two acquisition signals acquired from the preamble sections arranged in the transmission signal at a constant frequency. can do.
  • the second determination unit 49 notifies the control unit 8 of the determination result determined for the presence or absence of a signal. The details of the process of determining the absence of a transmission signal performed by the second determination unit 49 will be described later.
  • the transmission signal processing unit 6a uses the CDR (Clock Data Recovery) unit 50 that reproduces an operation clock synchronized with BBU2 from the transmission signal from the BBU2, and the reproduction clock that the CDR unit 50 reproduces.
  • a PLL 51 that generates a supply clock to be supplied to each device of the apparatus.
  • the CDR unit 50 detects the timing synchronized with the BBU2 obtained from the transmission signal, and adjusts the reproduction clock so that the phase of this timing is synchronized with the phase of the supply clock generated by the PLL 51, whereby the operation of the BBU2 A clock synchronized with the clock can be supplied.
  • the CDR unit 50 cannot obtain the synchronization timing based on the reference transmission signal when the transmission signal is completely lost or the signal absence state continues for a certain period, and cannot maintain the synchronization state. And an out-of-synchronization (out of lock) with the supply clock.
  • the CDR unit 50 detects the occurrence of a synchronization error (out of lock) between the synchronization timing and the supply clock as described above, so that the transmission signal is not transmitted at all or the state in which the transmission signal is absent continues for a certain period of time. Can be detected.
  • the CDR unit 50 outputs an unlock detection notification indicating that the unlocking has been detected to the control unit 8 and the second determination unit 49. Next, the process of determining the lack of signal of the transmission signal performed by the second determination unit 49 will be described.
  • FIG. 13 is a flowchart illustrating the signal lack determination process of the transmission signal performed by the second determination unit 49 in Chapter 2.
  • the second determination unit 49 acquires the correlation value from the correlation value calculation unit 47 (step S1)
  • the second determination unit 49 determines whether or not the unlock detection notification is received from the CDR unit 50 (step S2). If it is determined that the unlock detection notification is received from the CDR unit 50, the second determination unit 49 proceeds to step S12, notifies the control unit 8 of the first lack determination (step S12), and returns to the start. .
  • the first lack determination is a determination indicating that there is a signal shortage that is severe enough to restart the RRU3 or stop transmission.
  • the CDR unit 50 when the unlocking is detected, it indicates that the transmission signal is not transmitted at all or the absence of the signal continues for a certain period as described above. It is determined that there is a lack of signal, and the first lack determination is notified.
  • the control unit 8 that has received the first lack determination performs processing of restarting the RRU 3 or stopping transmission.
  • step S3 determines whether or not the correlation value is smaller than “0.5” (step S3). If it is determined that the correlation value is not smaller than “0.5”, that is, the correlation value is “0.5” or more, the second determination unit 49 further determines whether or not the correlation value is smaller than “0.9”. Is determined (step S4).
  • the second determination unit 49 notifies the control unit 8 of the first normal determination (step S5) and returns to the start.
  • the first normal determination is a determination indicating that there is no signal loss to the extent of a problem in performing wireless communication.
  • the control unit 8 that has received the first normal determination performs processing for leaving a log regarding the determination.
  • step S4 If it is determined in step S4 that the correlation value is not smaller than “0.9”, that is, the correlation value is “0.9” or more, the second determination unit 49 makes the second normal determination to the control unit 8. Notify (step S6) and return.
  • the second normal determination is a determination indicating that there is no signal loss. This is because when the correlation value is “0.9” or more, it can be determined that there is no lack of preamble signal in the preamble section.
  • the control unit 8 that has received the second normal determination recognizes that there is no lack of signal.
  • the second determination unit 49 notifies the control unit 8 of the first and second normal determinations (step S5).
  • step S6 it is determined that there is no signal loss in the transmission signal. That is, in the present embodiment, in determining the correlation value, “0.5” is set as a threshold value, and if it is smaller than “0.5”, there is no signal in one of the first and second acquired signals. And it is configured to determine that a lack of signal has occurred in the transmission signal.
  • the correlation value may be a value close to “0.5” and it may be determined that there is no signal loss. Therefore, the correlation value is “0.5” (third threshold) or more and “ When the second determination unit 49 determines that the value is smaller than “0.9” as the fourth threshold value, which is a value larger than 0.5, the control unit 8 performs processing for leaving a log regarding this determination. Thereby, even when it is determined that there is no lack of signal in the transmission signal, preventive processing can be performed by leaving a log of the determination.
  • step S3 when it is determined in step S3 that the correlation value is smaller than “0.5”, the second determination unit 49 has a time interval for acquiring the first and second acquisition signals by the signal acquisition units 44 and 45, It is determined whether or not the interval D L is set (step S7).
  • the second determination unit 49 sets the time interval for acquiring the first and second acquisition signals to the interval D L. transmitting a notification for changing the spacing D S is shorter interval than the control unit 8 (step S8).
  • the control unit 8 that has received the notification controls the signal acquisition units 44 and 45 so that the time interval for acquiring the first and second acquisition signals becomes the interval D S.
  • the time interval of obtaining the first and second acquisition signal is changed to the interval D S is shorter intervals.
  • step S7 if the time interval of obtaining the first and second acquisition signal is already assigned to a distance D S, the second determination unit 49 proceeds to step S9.
  • the second determination unit 49 when the second determination unit 49 has a correlation value smaller than “0.5” as the predetermined first threshold, the time for acquiring the acquisition signals by the signal acquisition units 44 and 45. Control is performed so that the interval is a small value D S. That is, since the correlation value is smaller than “0.5”, if the second determination unit 49 determines that the preamble signal is not included in the first or second acquisition signal and the transmission signal is missing, Since the time interval at which the control unit 8 acquires the first and second acquisition signals is reduced, it is possible to reliably determine the presence or absence of the signal even if the transmission signal is intermittently missing.
  • the second determination unit 49 obtains, as the frequency F, the number of times that the correlation value has been determined to be smaller than “0.5” during the past certain period, that is, the number of times that the signal lack has occurred in the transmission signal ( Step S9).
  • the second determination unit 49 determines whether or not the obtained frequency F is equal to or greater than a predetermined threshold F Th1 (step S10). If it is determined that the frequency F is not equal to or greater than the threshold value F Th1 , that is, smaller than the threshold value F Th1 , the second determination unit 49 proceeds to step S5 and notifies the control unit 8 of the first normal determination (step S5). ) Go back to the start.
  • the threshold value F Th1 is set to a value that is relatively low as the frequency of occurrence of signal loss and is not recognized as causing intermittent or continuous signal loss.
  • the second determination unit 49 determines that the frequency F is greater than a threshold value F Th1 as a predetermined threshold value. If it is smaller, it is determined that there is a sudden signal loss, and a first normal determination notification is made to determine that there is no signal loss in the transmission signal. Even if it is not recognized that the lack of signal of the transmission signal is intermittently generated, there is a possibility that the lack of signal may occur. Therefore, since the frequency F is smaller than the threshold value F Th1 , there is no lack of signal.
  • the second determination unit 49 When the second determination unit 49 makes a determination to be considered, the second determination unit 49 notifies the first normal determination to cause the control unit 8 to perform a process of leaving a log regarding this determination. Even if the frequency of the signal lack is small, it is determined that the signal lack has occurred. Therefore, it is possible to perform a preventive process by leaving a log regarding this determination.
  • step S10 if it is determined that the frequency F is the threshold value F Th1 or more, the second determination unit 49 determines whether the frequency F is the threshold value F Th2 or set to a value greater than the threshold value F Th1 (step S11).
  • the threshold value F Th2 is set to a value at which it is recognized that the lack of signal occurs intermittently or continuously as the frequency of occurrence of the lack of signal.
  • the second determination unit 49 When it is determined that the frequency F is equal to or greater than the threshold value F Th2 , the second determination unit 49 notifies the control unit 8 of the first lack determination (step S12) and returns.
  • the first lack determination is a determination indicating that a severe signal loss has occurred. Therefore, when the frequency F is equal to or higher than the threshold F Th2 which is another predetermined threshold, the second determination unit 49 determines that the transmission signal has a severe signal lack by notifying the first lack determination. It is configured as follows. Further, in this case, when the second determination unit 49 determines that the transmission signal has a severe signal lack, the control unit 8 stops transmission of the transmission signal or the own device according to the notification of the first lack determination. Perform the restart process. For this reason, it is possible to quickly stop transmission of the transmission signal as an appropriate process according to the determination of the second determination unit 49 or restart the own apparatus by the determination on the RRU 3 side.
  • step S11 when the frequency F is not equal to or higher than the threshold value F Th2 , that is, when the frequency F is equal to or higher than the threshold value F Th1 and is smaller than the threshold value F Th2 , the second determination unit 49 Is notified (step S13), and the process returns.
  • the second lack determination is a determination indicating that there is a slight signal lack that does not lead to a severe signal lack like the first lack determination.
  • the control unit 8 that has received the second lack determination performs a process of transmitting a warning such as an alarm for notifying that a signal lack has occurred to the BBU 2 and also performs a process of leaving a log regarding this determination.
  • the second determination unit 49 when the frequency F is equal to or higher than the threshold value F Th1 and smaller than the threshold value F Th2 , the second determination unit 49 notifies the second absence determination, thereby causing a slight signal lack in the transmission signal. Furthermore, if the second determination unit 49 determines that the transmission signal has a slight signal loss, the control unit 8 notifies the BBU 2 of a warning and records a log of the determination. In addition, it is possible to promptly notify the BBU 2 and record a log as appropriate processing according to the determination of the second determination unit 49 by the determination on the RRU 3 side.
  • the second determination unit 49 determines the number of times that it is determined that the correlation value is smaller than “0.5” during the past certain period.
  • the frequency F is obtained, and according to the frequency F, it can be determined whether the degree of signal lack in the transmission signal corresponds to mild or severe. That is, the second determination unit 49 converts the number of times that the correlation value is determined to be smaller than the predetermined second threshold value “0.5” into a frequency, and based on this frequency, the signal lack in the transmission signal The presence or absence of is determined as the degree.
  • the correlation value is smaller than the value “0.5” as the second threshold value, it is determined that a signal lack has occurred in the transmission signal.
  • the second determination unit 49 determines whether the signal lack is a slight signal lack or a severe signal lack, and determines that the signal lack is mild. In this case, the control unit 8 notifies the BBU 2 of a warning and records a log of this determination. When it is determined that the signal is severely absent, the transmission signal transmission is stopped and the own apparatus is restarted. Therefore, it is possible to quickly perform a suitable process according to the degree of lack of the transmission signal based on the determination on the wireless communication device side.
  • threshold values “0.5” and “0.9” related to the correlation values shown in step S3 and step S4 are shown as examples, and are not limited to these values.
  • the RRU 3 of the radio base station apparatus 1 is a radio communication apparatus in which a transmission signal in which a preamble section including a preamble signal is periodically arranged is given from the BBU 2, A second determination unit 49 is provided for determining the presence or absence of a signal in the transmission signal based on the correlation value obtained from the first and second acquisition signals indicating the detection result of the preamble signal.
  • the RRU 3 performs correlation based on the signal acquisition units 44 and 45 that acquire signals included in the preamble section of the transmission signal, and the first and second acquisition signals acquired by the signal acquisition units 44 and 45.
  • a correlation value calculation unit 47 that obtains a value as a detection result of the preamble signal in the transmission signal, and the second determination unit 49 determines a signal in the transmission signal based on the correlation value obtained by the correlation value calculation unit 47. It is configured to determine whether there is a lack.
  • the second determination unit 49 determines the presence or absence of a signal in the transmission signal based on the detection result of the preamble signal periodically arranged in the transmission signal.
  • the presence or absence of a signal can be determined for each period. As a result, even if the signal lack occurs intermittently in the transmission signal, it is possible to appropriately detect the signal lack in the transmission signal by periodically determining the presence or absence of the signal lack.
  • the correlation value calculation unit 47 obtains a correlation value between the first acquisition signal and the second acquisition signal acquired by the signal acquisition units 44 and 45.
  • the first acquisition signal and the second acquisition signal constitute a reference signal for determining whether one signal contains a known signal in the other signal.
  • the RRU 3 of the present embodiment has a function for compensating for distortion occurring in the input / output characteristics of the transmission amplifier 6e as an amplifier. That is, the RRU 3 of the present embodiment has a transmission amplifier 6e that outputs a transmission signal as an input signal and an amplified transmission signal as an output signal, and input / output of the transmission amplifier 6e as a function for performing distortion compensation. And a distortion compensation unit 41 that compensates for distortion occurring in characteristics.
  • the signal acquisition units 44 and 45 acquire a signal included in a preamble section in the input signal and the output signal as a first acquisition signal and a second acquisition signal, and give the acquired signal to the correlation value calculation unit 47. Furthermore, the correlation value calculation unit 47 and the first determination unit 48, the distortion compensation unit 41 is provided.
  • the signal acquisition units 44 and 45 acquire the input signal and output signal of the transmission amplifier 6e necessary for the distortion compensation unit 41 to perform distortion compensation of the transmission amplifier 6e, and the correlation value calculation unit 47 Since the correlation value is obtained by using these input / output signals, the second determination unit 49 and the distortion compensation unit 41 can serve as the signal acquisition units 44 and 45, and the apparatus scale can be made compact.
  • FIG. 14 is a block diagram illustrating a configuration of the transmission signal processing unit 6a according to the second embodiment in Chapter 2.
  • the difference between the present embodiment and the first embodiment is that the second correlation that gives the correlation value to the second determination unit 49 in addition to the (first) correlation value calculation unit 47 that gives the correlation value to the first determination unit 48
  • a delay calculation unit 52 that is connected between the ADC 6 i (FIG. 9) and the (first) output signal buffer unit 43 and that receives the output signal, and a delay output from the delay processing unit 52.
  • the second output signal buffer unit 53 that acquires and stores the processed output signal, and the signal included in the preamble section (FIG. 8) is acquired as an acquisition signal from the output signal stored in the second output signal buffer unit 53. It is the point which is equipped with the signal acquisition part 54 which performs.
  • the delay processing unit 52 performs a delay process for delaying the output signal by a predetermined delay time. Therefore, the output signal accumulated in the second output signal buffer unit 53 is delayed by a predetermined delay time with respect to the output signal of the first output signal buffer unit 43.
  • the signal acquisition unit 54 acquires a signal included in the preamble section of the output signal delayed by a predetermined delay time as an acquisition signal, and calculates the acquired signal (hereinafter also referred to as a third acquisition signal) as a second correlation value. This is output to the unit 55. Therefore, the third acquisition signal is delayed by a predetermined delay time with respect to the second acquisition signal, and the signal acquired from the preamble section at a different timing from the preamble section from which the second acquisition signal was acquired; Become.
  • the second correlation value calculation unit 55 obtains a correlation value between the second acquisition signal from the signal acquisition unit 45 and the third acquisition signal from the signal acquisition unit 54.
  • the second correlation value calculation unit 55 obtains a correlation value using the second and third acquired signals that are two acquired signals acquired from preamble sections having different timings. In this case, a high correlation value is obtained if both the second acquisition signal and the third acquisition signal include a preamble signal, and low if either or both (due to lack) do not include a preamble signal. A correlation value is obtained.
  • the second correlation value calculation unit 55 can obtain the correlation value as a detection result of the presence / absence of the preamble signal in the transmission signal.
  • the input signal and the output signal are synchronized so that they are radio frames having the same timing.
  • the first and second acquisition signals may be signals acquired from preamble sections at the same timing.
  • the correlation value can be obtained from the signals acquired from the two preamble sections at different timings by the delay processing unit 52, the preamble signal included in the transmission signal is more efficiently used. Can be detected well.
  • the apparatus scale can be made compact.
  • FIG. 15 is a block diagram showing the configuration of the transmission signal processing unit 6a according to the third embodiment in Chapter 2.
  • the difference between the present embodiment and the second embodiment is that a second input signal buffer unit 60, a delay processing unit 62, and a third unit are used as functional units for acquiring an acquisition signal given to the second correlation value calculation unit 55.
  • An input signal buffer unit 63 and signal acquisition units 61 and 64 are provided.
  • the second input signal buffer unit 60 and the delay processing unit 62 are connected to the subsequent stage of the distortion compensation unit 41, and both acquire an input signal.
  • the second input signal buffer unit 60 acquires and accumulates input signals.
  • the signal acquisition unit 61 connected to the second input signal buffer unit 60 acquires a signal included in the preamble section (hereinafter also referred to as a fourth acquisition signal) from the input signal accumulated in the second input signal buffer unit 60. And output to the second correlation value calculation unit 55.
  • the delay processing unit 62 performs a delay process for delaying the input signal by a predetermined delay time. Therefore, the input signal accumulated in the third input signal buffer unit 63 is delayed by a predetermined delay time with respect to the input signal of the second input signal buffer unit 60.
  • the signal acquisition unit 64 connected to the third input signal buffer unit 63 acquires a signal included in the preamble section of the input signal delayed by a predetermined delay time, and acquires the acquired signal (hereinafter also referred to as a fifth acquisition signal). Is output to the second correlation value calculation unit 55. Therefore, the fifth acquisition signal is delayed by a predetermined delay time with respect to the fourth acquisition signal, and a signal acquired from a preamble section at a different timing from the preamble section from which the fourth acquisition signal was acquired; Become.
  • the second correlation value calculation unit 55 obtains a correlation value between the fourth acquisition signal from the signal acquisition unit 61 and the fifth acquisition signal from the signal acquisition unit 64.
  • the second correlation value calculation unit 55 calculates a correlation value using the fourth and fifth acquisition signals acquired from the preamble sections at different timings. Thereby, the second correlation value calculation unit 55 can obtain the correlation value as a detection result of the presence / absence of the preamble signal in the transmission signal.
  • the function unit for acquiring an acquisition signal for obtaining a correlation value necessary for performing the determination is provided separately from the function unit for performing distortion compensation.
  • An acquisition signal can be acquired at a timing suitable for determination.
  • FIG. 16 is a block diagram illustrating a configuration of a transmission signal processing unit 6a according to the fourth embodiment in Chapter 2.
  • the difference between the present embodiment and the third embodiment is whether the fourth acquisition signal includes a preamble signal instead of the delay processing unit 62, the third input signal buffer unit 63, and the signal acquisition unit 64.
  • This is the point that a storage unit 65 that stores in advance a preamble signal for determining whether or not.
  • the second correlation value calculation unit 55 of the present embodiment obtains a correlation value between the fourth acquisition signal from the signal acquisition unit 61 and the preamble signal stored in the storage unit 65. Based on this correlation value, the second determination unit 49 determines whether there is a signal lack in the transmission signal.
  • the storage unit 65 stores preamble signals of all patterns as data.
  • the second correlation value calculation unit 55 can specify the current preamble signal pattern based on the notification from the BBU 2, reads the preamble signal of the specified pattern from the storage unit 65, and uses it for calculating the correlation value.
  • a correlation value with the preamble signal stored in advance in the storage unit 65 can be obtained, and the presence or absence of a signal in the transmission signal can be determined. As a result, the process related to determination is simplified.
  • the second correlation value calculation unit 55 obtains correlation values between the preamble signals of all patterns and the current preamble signal.
  • the current preamble signal can also be specified.
  • Radio base station equipment wireless communication system
  • Baseband unit baseband processing device
  • Remote radio unit wireless communication device
  • Control Unit 41
  • Signal Acquisition Unit 47
  • First) Correlation Value Calculation Unit 48
  • First Determination Unit (Other Determination Unit)
  • Second determination unit determination unit
  • Second correlation value calculation unit 65 Storage unit
  • FIG. 17 is a diagram showing the configuration of the wireless communication apparatus according to the first embodiment of the present invention in Chapter 3.
  • radio communication apparatus 201 is, for example, a radio base station apparatus, and includes one or a plurality of remote radio heads (RRH) 101 and main body apparatus 102.
  • RRH remote radio heads
  • the wireless communication apparatus 201 is provided in, for example, a WiMAX (Worldwide Interoperability for Microwave Access) system.
  • WiMAX Worldwide Interoperability for Microwave Access
  • a TDD (Time Division Duplex) method is adopted. That is, in the WiMAX system, an uplink transmission period for transmitting communication data from the radio terminal apparatus to the radio base station apparatus and a downlink transmission period for transmitting communication data from the radio base station apparatus to the radio terminal apparatus are switched. Are repeated alternately.
  • the wireless communication device 201 performs transmission and reception of communication data with the wireless terminal device 301 by switching over time.
  • the communication data generated in the wireless communication device 201 and the wireless terminal device 301 are subjected to various signal processing by the wireless communication device 201 and the wireless terminal device 301 in accordance with the WiMAX standard, and finally are converted into wireless signals. After the conversion, the data are transmitted to the wireless terminal device 301 and the wireless communication device 201, respectively.
  • the remote radio head 101 is attached to an antenna pole 104 installed on the rooftop of the building.
  • An antenna 103 is attached to the antenna pole 104.
  • the remote radio head 101 converts a radio signal received from the radio terminal device 301 via the antenna 103 into a digital signal and outputs the digital signal to the main device 102 via the optical fiber 105. Further, the remote radio head 101 converts a digital signal received from the main body apparatus 102 via the optical fiber 105 into a radio signal and transmits the radio signal to the radio terminal apparatus 301 via the antenna 103.
  • FIG. 18 is a functional block diagram of the remote radio head according to the first embodiment of the present invention in Chapter 3.
  • the remote radio head 101 includes a signal processing unit 81, a wireless transmission unit 71, a wireless reception unit 72, and a transmission / reception changeover switch 86.
  • the wireless transmission unit 71 includes a digital / analog converter (DAC) 82, a modulator 83, a driver amplifier 84, a power amplifier 85, and an oscillator 87.
  • the radio reception unit 72 includes reception amplifiers 89 and 90, a mixer 91, a BPF (Band Pass Filter) 92, an analog / digital converter (ADC) 93, and an oscillator 94.
  • the signal processing unit 81 includes a synchronization processing unit 51.
  • the signal processing unit 81 performs signal processing on the digital signal received from the main body device 102 via the optical fiber 105 and outputs the signal to the wireless transmission unit 71.
  • the synchronization processing unit 51 In the signal processing unit 81, the synchronization processing unit 51 generates a reference timing signal for the remote radio head 101 to operate in synchronization with the main body device 102 based on reception data that is a digital signal received from the main body device 102. .
  • the wireless transmission unit 71 converts the digital signal received from the signal processing unit 81 into an analog signal, converts the converted analog signal into a radio signal, that is, an RF (Radio-Frequency) band signal, and transmits the signal to the wireless terminal device 301.
  • a radio signal that is, an RF (Radio-Frequency) band signal
  • the wireless reception unit 72 receives a wireless signal from the wireless terminal device 301 and converts it into an IF (Intermediate Frequency) signal, converts the converted IF signal into a digital signal, and outputs the digital signal to the signal processing unit 81.
  • IF Intermediate Frequency
  • the signal processing unit 81 performs various signal processing on the digital signal received from the wireless reception unit 72 and outputs the digital signal to the main unit 102 via the optical fiber 105.
  • the digital / analog converter 82 converts the digital signal received from the signal processing unit 81 into an analog signal and outputs the analog signal to the modulator 83.
  • the oscillator 87 generates a local oscillation signal and outputs it to the modulator 83.
  • Modulator 83 multiplies the baseband analog signal received from digital / analog converter 82 by the local oscillation signal received from oscillator 87, for example, to orthogonally modulate the analog signal received from digital / analog converter 82. Then, it is converted into a radio signal and output to the driver amplifier 84.
  • the driver amplifier 84 amplifies the radio signal received from the modulator 83 and outputs it to the power amplifier 85.
  • the power amplifier 85 further amplifies the radio signal received from the driver amplifier 84.
  • the wireless signal amplified by the power amplifier 85 is transmitted to the wireless terminal device 301 via the transmission / reception selector switch 86 and the antenna 103.
  • the receiving amplifier 89 is, for example, an LNA (Low Noise Amplifier), receives a wireless signal from the wireless terminal device 301 via the antenna 103 and the transmission / reception selector switch 86, amplifies the received wireless signal, and outputs the amplified signal to the receiving amplifier 90. .
  • LNA Low Noise Amplifier
  • the reception amplifier 90 is, for example, an LNA, and further amplifies the radio signal received from the reception amplifier 89 and outputs the amplified signal to the mixer 91.
  • the oscillator 94 generates a local oscillation signal and outputs it to the mixer 91.
  • Mixer 91 multiplies the radio signal received from reception amplifier 90 by the local oscillation signal received from oscillator 94, thereby converting the radio signal received from reception amplifier 90 into an IF signal and outputs the IF signal to bandpass filter 92. .
  • the band pass filter 92 outputs to the analog / digital converter 93 a signal obtained by attenuating a component outside the predetermined frequency band among the frequency components of the IF signal received from the mixer 91.
  • the analog / digital converter 93 converts the IF signal received from the band pass filter 92 into a digital signal and outputs the digital signal to the signal processing unit 81.
  • the signal processing unit 81 performs, for example, orthogonal demodulation on the IF band digital signal received from the analog / digital converter 93 to convert it into a baseband digital signal, and outputs the baseband digital signal to the main unit 102 via the optical fiber 105.
  • the transmission / reception selector switch 86 outputs a radio signal received from the power amplifier 85 to the antenna 103 based on a control signal (not shown) received from the signal processing unit 81 or outputs a radio signal received from the antenna 103 to the reception amplifier 89. Switch what to do.
  • FIG. 19 is a diagram showing a configuration of a synchronization processing unit in the remote radio head according to the first embodiment of the present invention in Chapter 3.
  • the synchronization processing unit 51 includes a CDR (Clock and Data Recovery) unit 11, a jitter suppression unit 12, and an oscillator control unit 13.
  • the CDR unit 11 includes a retiming unit 21 and a timing signal generation unit 22.
  • the jitter suppression unit 12 includes a phase comparator 23, a loop filter 24, and a VCXO (Voltage Controlled Crystal Oscillator) 25.
  • the oscillator control unit 13 includes a switch 26, comparators 27, 28 and 29, and a low pass filter 30.
  • the CDR unit 11 reshapes the received data received from the main device 102 and extracts timing from the received data. Specifically, the CDR unit 11 generates and outputs a reproduction timing signal from received data that is a digital signal received from the main device 102.
  • the timing signal generation unit 22 generates a reproduction timing signal that is, for example, a clock based on the received data received from the main body device 102.
  • the timing signal generation unit 22 extracts the timing, for example, by monitoring the rising and falling edges of the digital signal received from the main device 102.
  • the retiming unit 21 reshapes the received data by retiming the received data from the main device 102 using the reference timing signal whose jitter is suppressed by the jitter suppressing unit 12. That is, the retiming unit 21 holds and outputs received data in response to the reference timing signal generated by the jitter suppressing unit 12.
  • the jitter suppression unit 12 controls the VCXO 25 based on the timing extracted by the CDR unit 11. More specifically, the jitter suppression unit 12 includes a VCXO 25, generates the control voltage VC1 based on the reproduction timing signal generated by the timing signal generation unit 22, and supplies the control voltage VC1 to the VCXO 25. Thus, the jitter suppression unit 12 generates a reference timing signal having a frequency component obtained by attenuating a component equal to or higher than a predetermined frequency among the frequency components of the reproduction timing signal and synchronized with the reproduction timing signal.
  • the jitter suppression unit 12 constitutes a PLL circuit. That is, in the jitter suppression unit 12, the phase comparator 23 compares the phase of the reproduction timing signal received from the timing signal generation unit 22 with the phase of the reference timing signal received from the VCXO 25, and outputs a phase difference signal indicating the comparison result. Output. This phase difference signal corresponds to the control voltage VC1 of the VCXO 25 in the synchronized state.
  • the followability of the PLL circuit is set by the time constant of the loop filter 24. Specifically, the time constant of the loop filter 24 is set so that the PLL circuit does not follow noise having high frequency components such as harmonics.
  • VCXO 25 generates an oscillation signal and outputs it as a reference timing signal.
  • the VCXO 25 changes the frequency of the oscillation signal according to the control voltage received from the oscillator control unit 13.
  • the oscillation signal output from the VCXO 25 is output to each circuit in the retiming unit 21, the phase comparator 23, and the remote radio head 101.
  • the oscillator control unit 13 detects an abnormality in the reproduction timing signal generated by the timing signal generation unit 22, and when detecting the abnormality, a control that is a voltage within the control range CRG instead of the control voltage VC1.
  • the voltage VC2 is supplied to the VCXO 25.
  • the comparator 27 functions as a buffer, and outputs the phase difference signal that has passed through the loop filter 24 in the jitter suppression unit 12 to the low-pass filter 30.
  • the low-pass filter 30 outputs a signal obtained by attenuating a component having a predetermined frequency or higher among the frequency components of the phase difference signal received from the comparator 27.
  • the comparator 28 compares the phase difference signal that has passed through the low-pass filter 30 with the threshold voltage Vth1, and outputs a signal indicating the comparison result to the switch 26.
  • the comparator 29 compares the phase difference signal that has passed through the low-pass filter 30 with the threshold voltage Vth2, and outputs a signal indicating the comparison result to the switch 26.
  • the oscillator control unit 13 detects an abnormality in the reproduction timing signal based on the comparison result by the comparator 28 and the comparison result by the comparator 29.
  • the switch 26 Based on the signals received from the comparator 28 and the comparator 29, the switch 26 selects one of the phase difference signal, the threshold voltage Vth1 and the threshold voltage Vth2 that has passed through the loop filter 24, and supplies the control voltage to the VCXO 25. Supply. That is, based on the comparison result by the comparator 28 and the comparison result by the comparator 29, the switch 26 outputs the threshold voltage Vth1 as the control voltage VC2 to the VCXO 25 or outputs the threshold voltage Vth2 as the control voltage VC2 to the VCXO 25. Alternatively, it is switched whether to output the control voltage VC1 generated by the timing signal generation unit 22 to the VCXO 25.
  • FIG. 20 is a diagram showing an abnormality detection operation in the synchronization processing unit according to the first embodiment of the present invention in Chapter 3.
  • the threshold voltage Vth2 is larger than the threshold voltage Vth1.
  • the threshold voltage Vth1 and the threshold voltage Vth2 are set so that the PLL circuit configured by the jitter suppression unit 12 is in an asynchronous state if the control voltage supplied to the VCXO 25 is within the range of the threshold voltage Vth1 to the threshold voltage Vth2. It is set to a value that does not occur. That is, a range from the threshold voltage Vth1 to the threshold voltage Vth2 is set as the normal range NRG of the PLL circuit.
  • the oscillator control unit 13 measures the control voltage VC1 generated in the jitter suppression unit 12, and determines that an abnormality has occurred when the control voltage VC1 is outside the normal range NRG.
  • the oscillator control unit 13 further suppresses jitter when the control voltage VC1 generated by the jitter suppression unit 12 is within the range of the threshold voltage Vth1 to the threshold voltage Vth2. It is determined that the PLL circuit configured by the unit 12 is operating normally and the reproduction timing signal output from the CDR unit 11 is normal. In this case, the oscillator control unit 13 supplies the phase difference signal that has passed through the loop filter 24, that is, the control voltage VC1, to the VCXO 25.
  • the oscillator control unit 13 has an abnormality in the PLL circuit configured by the jitter suppression unit 12. It is determined that the reproduction timing signal output from the CDR unit 11 is abnormal.
  • the oscillator control unit 13 measures the control voltage VC1 generated in the jitter suppression unit 12, and controls the maximum voltage in the control range CRG when the control voltage VC1 exceeds the maximum value in the normal range NRG.
  • the voltage VC2 is supplied to the VCXO 25. Further, when the control voltage VC1 is lower than the minimum value in the normal range NRG, the oscillator control unit 13 supplies the voltage of the minimum value in the control range CRG to the VCXO 25 as the control voltage VC2.
  • the control range CRG and the normal range NRG match. That is, the comparator 28 compares the phase difference signal that has passed through the low-pass filter 30 with the threshold voltage Vth1, and outputs a logic high level signal to the switch 26 when the phase difference signal is greater than the threshold voltage Vth1, When the phase difference signal is smaller than the threshold voltage Vth1, a logic low level signal is output to the switch 26.
  • the comparator 29 compares the phase difference signal that has passed through the low-pass filter 30 with the threshold voltage Vth2. If the phase difference signal is smaller than the threshold voltage Vth2, the comparator 29 outputs a logic high level signal to the switch 26. When the signal is larger than the threshold voltage Vth2, a logic low level signal is output to the switch 26.
  • the switch 26 When the switch 26 receives a logic high level signal from the comparator 28 and receives a logic high level signal from the comparator 29, the switch 26 outputs the phase difference signal that has passed through the loop filter 24, that is, the control voltage CV1. Supply to VCXO25.
  • the switch 26 When the switch 26 receives a logic low level signal from the comparator 28 and receives a logic high level signal from the comparator 29, the switch 26 supplies the threshold voltage Vth1 to the VCXO 25 as the control voltage CV2. .
  • the switch 26 when the switch 26 receives a logic high level signal from the comparator 28 and receives a logic low level signal from the comparator 29, the switch 26 supplies the threshold voltage Vth2 to the VCXO 25 as the control voltage CV2. .
  • FIG. 21 is a diagram showing a modification of the relationship between the threshold voltage and the control voltage in the synchronization processing unit according to the first embodiment of the present invention in Chapter 3.
  • the threshold voltage Vth1 or the threshold voltage Vth2 corresponding to the normal / abnormal determination boundary is described, but the present invention is not limited to this. It is only necessary that at least a part of each of the control range CRG and the normal range NRG overlap.
  • the oscillator control unit 13 supplies a control voltage VC1 that is lower than the threshold voltage Vth1 to the VCXO 25.
  • the oscillator control unit 13 supplies the control voltage VC2 that is higher than the threshold voltage Vth2 to the VCXO 25.
  • the PLL circuit becomes in an asynchronous state. Then, depending on the time constant of the PLL circuit, it may take time to return to the synchronous state, and the influence on communication may be increased.
  • the main device 102 does not transmit a reference timing signal such as a clock to the remote radio head 101. For this reason, the remote radio head 101 needs to newly generate a reference timing signal based on the data transmitted from the main device 102 and operate based on the reference timing signal.
  • the reproduction timing signal generated by the CDR unit 11 includes many unnecessary spurious components, that is, jitter components, the reproduction timing signal is directly used as a reference of the PLL circuit in the wireless transmission unit 71, the wireless reception unit 72, and the like. It is difficult to use as a timing signal.
  • the jitter suppression unit 12 reduces phase noise by reducing noise of components having a relatively high frequency such as harmonic components included in the reproduction timing signal.
  • the optical signal transmitted from the main body apparatus 102 is generated by a highly accurate timing signal in the main body apparatus 102.
  • the optical signal includes a fluctuation component.
  • the PLL circuit configured by the jitter suppression unit 12 needs to follow this fluctuation in order to synchronize with the main device 102. For this reason, the jitter suppression unit 12 passes a very low frequency component without removing it, and removes a component having a relatively high frequency such as a harmonic component and a digital signal component. Therefore, a large value is set for the time constant of the loop filter 24 in the PLL circuit, and the response speed of the PLL circuit becomes slow.
  • the reproduction timing signal from the CDR unit 11 when the optical signal from the main unit 102 cannot be received, such as when the optical fiber cable is cut off, the reproduction timing signal from the CDR unit 11, for example, the extracted clock becomes inaccurate. 102 cannot be synchronized. And since the time constant of the PLL circuit comprised by the jitter suppression part 12 as mentioned above is large, even if the interruption
  • the PLL circuit takes several tens of ms to return to the synchronized state, one frame is 5 ms in the WiMAX system, and thus it takes time for at least several frames to return to the synchronized state. The impact on communications will increase.
  • the timing signal generation unit 22 generates a reproduction timing signal based on the received data received from the main body apparatus 102.
  • the jitter suppression unit 12 includes a VCXO 25, generates the control voltage VC1 based on the reproduction timing signal generated by the timing signal generation unit 22, and supplies the control voltage VC1 to the VCXO 25.
  • the jitter suppression unit 12 generates a reference timing signal having a frequency component obtained by attenuating a component equal to or higher than a predetermined frequency among the frequency components of the reproduction timing signal and synchronized with the reproduction timing signal.
  • the oscillator control unit 13 detects an abnormality in the reproduction timing signal generated by the timing signal generation unit 22, and when the abnormality is detected, a control that is a voltage within the control range CRG instead of the control voltage VC1.
  • the voltage VC2 is supplied to the VCXO 25.
  • the control voltage VC1 generated in the jitter suppression unit 12 is monitored, and threshold voltages are provided above and below the control voltage VC1.
  • the lock voltage that is, the PLL circuit follows the control voltage. Keep it within the possible range to prevent the control voltage from running out of the lock range.
  • the convergence time until the PLL circuit locks and generates a normal reference timing signal after the optical fiber cable is disconnected and the digital signal from the main unit 102 can be received is greatly increased. It can be shortened.
  • the operation can be continued with the reference timing signal without depending on the signal from the main unit 102. For example, it is possible to perform an operation for notifying other devices of an abnormality.
  • the remote radio head 101 is not limited to an abnormal state outside the remote radio head 101 such as a cut-off state of the optical fiber cable, but a malfunction of the CDR unit 11 or the like. Even if an abnormality occurs in the interior, it is possible to quickly return to the normal state.
  • the oscillator control unit 13 measures the control voltage VC1 generated in the jitter suppression unit 12, and the control voltage VC1 is outside the normal range NRG. In the case, it is determined that an abnormality has occurred.
  • the oscillator control unit 13 measures the control voltage VC1 generated in the jitter suppression unit 12, and the control voltage VC1 has a maximum value in the normal range NRG. When it exceeds, the maximum voltage in the control range CRG is supplied to the VCXO 25 as the control voltage VC2. Further, when the control voltage VC1 is lower than the minimum value in the normal range NRG, the oscillator control unit 13 supplies the voltage of the minimum value in the control range CRG to the VCXO 25 as the control voltage VC2.
  • a voltage close to the control voltage at the time of abnormality detection for example, at the time of detection of loss of synchronization of the PLL circuit, is selected as the control voltage supplied to the VCXO 25 in the abnormal state. It is not necessary to discharge or store electricity significantly, and the operation of the PLL circuit can be stabilized.
  • control range CRG and the normal range NRG match.
  • each range can be defined by two voltages, so that the circuit configuration can be simplified.
  • the comparator 28 compares the control voltage VC1 with the threshold voltage Vth1.
  • the comparator 29 compares the threshold voltage Vth2 different from the threshold voltage Vth1 with the control voltage VC1. Then, the oscillator control unit 13 detects an abnormality in the reproduction timing signal based on the comparison result by the comparator 28 and the comparison result by the comparator 29.
  • the abnormality detection and the switching of the control voltage can be performed quickly.
  • the oscillator control unit 13 when a digital circuit composed of an A / D converter, a D / A converter, or the like is used as the oscillator control unit 13, it does not depend on the reference timing signal so that it can operate even when the reproduction timing signal is abnormal. A circuit capable of outputting a free-running clock is required.
  • the use of an analog circuit constituted by a comparator eliminates the need for such an oscillation circuit and simplifies the configuration. Can do.
  • the switch 26 outputs the threshold voltage Vth1 to the VCXO 25 as the control voltage VC2 based on the comparison result by the comparator 28 and the comparison result by the comparator 29. Or the threshold voltage Vth2 is output to the VCXO 25 as the control voltage VC2, or the control voltage VC1 generated by the timing signal generator 22 is output to the VCXO 25.
  • the oscillator control unit 13 can switch the control voltage with a simple configuration by selecting each voltage using the switch.
  • the retiming unit 21 holds and outputs received data in response to the reference timing signal generated by the jitter suppression unit 12.
  • the reception characteristics in the remote radio head 101 can be improved by retiming the reception data from the main unit 102 using the reference timing signal in which jitter is suppressed.
  • the wireless communication apparatus transmits and receives a wireless signal conforming to the WiMAX standard.
  • the usefulness of the present invention can be utilized under the severe time constraints in the TDD scheme for exchanging data with a frame configuration.
  • the oscillator control unit 13 is configured to select the threshold voltage Vth1 or the threshold voltage Vth2 that is a fixed voltage as the control voltage VC2 in the abnormal state.
  • the control voltage VC2 in the abnormal state does not need to be a fixed voltage, and may be a voltage that varies within a predetermined range.
  • the oscillator control unit 13 detects an abnormality in the reproduction timing signal by measuring the control voltage VC1 generated in the jitter suppression unit 12.
  • the oscillator control unit 13 may be configured to detect an abnormality in the reproduction timing signal by monitoring some value that changes in accordance with the state of the reproduction timing signal or the reference timing signal.
  • the oscillator controller 13 may be configured to monitor the frequency of the reference timing signal and detect an abnormality in the reproduction timing signal based on this.
  • a self-running oscillator different from the VCXO 25 is provided, and an abnormality in the reproduction timing signal is detected by comparing the oscillation frequency of the oscillator with the frequency of the reference timing signal.
  • the radio communication apparatus is a radio base station apparatus including a remote radio head, but the present invention is not limited to this, and based on a signal from the target apparatus. Any device that synchronizes with the target device may be used.
  • the present embodiment relates to a wireless communication apparatus in which the configuration of the oscillator control unit is changed as compared with the wireless communication apparatus according to the first embodiment.
  • the contents other than those described below are the same as those of the wireless communication apparatus according to the first embodiment.
  • FIG. 22 is a diagram showing the configuration of the synchronization processing unit in the remote radio head according to the second embodiment of the present invention in Chapter 3.
  • the remote radio head includes a synchronization processing unit 52 instead of the synchronization processing unit 51.
  • the synchronization processing unit 52 includes a CDR unit 11, a jitter suppression unit 12, and an oscillator control unit 14.
  • the oscillator control unit 14 includes a switch 31, a comparator 32, a low-pass filter 33, an A / D converter 34, a determination unit 35, and a D / A converter 36.
  • the comparator 32 functions as a buffer, and outputs the phase difference signal that has passed through the loop filter 24 in the jitter suppression unit 12 to the low-pass filter 33.
  • the low-pass filter 33 outputs a signal obtained by attenuating a component equal to or higher than a predetermined frequency among the frequency components of the phase difference signal received from the comparator 32.
  • the A / D converter 34 converts the phase difference signal, which is an analog signal that has passed through the low-pass filter 33, into a digital signal and outputs it to the determination unit 35.
  • the determination unit 35 detects an abnormality in the reproduction timing signal based on the digital signal received from the A / D converter 34, generates the control voltage VC2 in the abnormal state, and controls the switch 31.
  • the D / A converter 36 converts the digital signal received from the determination unit 35 into an analog signal and outputs the analog signal to the switch 31.
  • the switch 31 Based on the control signal received from the determination unit 35, the switch 31 selects either the phase difference signal that has passed through the loop filter 24 or the signal received from the D / A converter 36, and supplies it to the VCXO 25 as a control voltage. .
  • the determination unit 35 includes a PLL circuit configured by the jitter suppression unit 12. It is operating normally, and the reproduction timing signal output from the CDR unit 11 is determined to be normal. In this case, the determination unit 35 controls the switch 31 to supply the phase difference signal that has passed through the loop filter 24, that is, the control voltage VC1 to the VCXO 25.
  • the determination unit 35 when the control voltage VC1 generated in the jitter suppression unit 12 falls outside the range from the threshold voltage Vth1 to the threshold voltage Vth2, the determination unit 35 generates an abnormality in the PLL circuit configured by the jitter suppression unit 12. The reproduction timing signal output from the CDR unit 11 is determined to be abnormal. In this case, the determination unit 35 controls the switch 31 to supply the signal output from the D / A converter 36 to the VCXO 25 as the control voltage VC2.
  • the oscillator control unit 14 uses a digital circuit configured by an A / D converter, a D / A converter, and the like, so that an abnormality determination criterion and an abnormal state are obtained. It is possible to set the control voltage at a more flexible.
  • FIG. 23 shows a radio base station apparatus 1 as an example of a radio communication system in Chapter 4.
  • the wireless communication base station device 1 is a device to which a terminal device such as a mobile phone is wirelessly connected.
  • the radio base station apparatus 1 is a system including a baseband unit (hereinafter sometimes simply referred to as “BBU”) 2 and a remote radio unit (hereinafter also simply referred to as “RRU”) 3. is there.
  • BBU baseband unit
  • RRU remote radio unit
  • this radio base station apparatus 1 is based on LTE, for example, and performs transmission / reception by a FDD system.
  • the BBU 2 and the RRU 3 are connected by a transmission line such as an optical fiber 4.
  • An electric cable may be adopted as the transmission line instead of the optical fiber.
  • not only one RRU 3 but also a plurality of RRUs 3 may be connected to one BBU 2.
  • a CPRI Common Public Radio Interface
  • BBU2 is called REC (Radio Equipment Control)
  • RRU3 is called RE (Radio Equipment).
  • the BBU 2 is a baseband signal that processes a baseband signal passed between the upper network I / F 21 for connecting to the upper network of the radio base station apparatus 1, the communication control unit 22 that controls communication, and the RRU 3.
  • the unit 23 and the optical I / F 24 are provided.
  • the RRU 3 includes an optical I / F 31 and a signal processing unit 32 that processes a high-frequency signal transmitted and received from the antenna 33.
  • the optical I / F 24 and the optical I / F 31 are interface units for performing transmission / reception of a CPRI-compliant frame (CPRI frame), and perform transmission control processing compliant with the CPRI.
  • CPRI frame CPRI-compliant frame
  • FIG. 24 shows details of the signal processing unit 32 of the RRU 3 in Chapter 4.
  • the RRU 3 has one transmitter 40 and one receiver 50.
  • the transmitter 40 includes a transmission digital signal processing unit 41, a DAC (DA converter) 42, a modulator 43, a transmission local oscillator 44, and a transmission amplifier 45.
  • DAC DAC
  • the transmission digital signal processing unit 41 is connected to the optical I / F 31, processes the digital signal (IQ signal) transmitted from the BBU 2, and outputs it to the DAC 42.
  • the DAC 42 converts the digital signal into an analog signal and outputs the analog signal to the modulator 43.
  • the modulator 43 modulates the high frequency signal from the transmission local oscillator 44 and outputs the modulated signal to the transmission amplifier 45.
  • the transmission amplifier 45 amplifies the signal and outputs the signal from the antenna 33 via the duplexer 46.
  • the receiver 50 includes a reception digital signal processing unit 51, an ADC (AD converter) 52, a BPF (band pass filter) 53, a mixer 54, and a reception amplifier 56.
  • a signal received by the antenna 33 is given to the reception amplifier 56 via the duplexer 46.
  • the reception amplifier 56 amplifies the reception signal and outputs it to the mixer 54.
  • the mixer 54 converts the frequency of the received signal into a predetermined frequency.
  • a reception local oscillator 55 is connected to the mixer 54.
  • the reception local oscillator 55 generates a high frequency signal required for the mixer 54 to convert the signal to a predetermined frequency.
  • the output of the mixer 54 is given to the ADC 52 via the BPF.
  • the ADC 52 converts an analog signal into a digital signal and outputs the digital signal to the received digital signal processing unit 51.
  • the reception digital signal processing unit 51 transmits an IQ signal obtained by orthogonal demodulation of the reception signal to the BBU 2 via the optical I / F 31.
  • the RRU 3 includes a monitoring control unit (CPU) 63 that monitors the operation and the like in the RRU 3.
  • the monitoring control unit (hereinafter simply referred to as “control unit”) 63 of the present embodiment has an autonomous DFS function, and the control performed between the BBU 2 and the RRU 3 for the DFS is simplified. Yes.
  • the radio base station apparatus 1 that performs DFS measures the signal level of each of a plurality of frequency channels. If the signal level is higher than a predetermined threshold, another radio base station apparatus uses the frequency channel. If it is lower than the threshold value, it is determined that the frequency channel is free.
  • the RRU 3 includes a detector (detection unit) 61 that detects the signal level of the analog reception signal in the receiver 50.
  • the signal level detected by the detector 61 is converted into a digital signal by the ADC 62 and given to the control unit 63.
  • the reception signal level may be detected digitally by the reception digital signal processing unit 51 instead of being detected by the analog detector 61.
  • the reception level can be obtained by the envelope level of the signal ( ⁇ (I2 + Q2)).
  • the control unit 63 has a function of autonomously determining the frequency of the signal detected by the detector 61.
  • the frequency of the signal detected by the detector 61 can be changed by changing the frequency of the reception local oscillator 55.
  • the control unit 63 outputs to the reception local oscillator 55 an instruction for changing the frequency of the reception local oscillator 55 to a frequency for generating a frequency (detection frequency) determined by itself.
  • the reception local oscillator 55 that has received the instruction changes the frequency in accordance with the instruction.
  • control unit 63 of the present embodiment can autonomously determine the frequency of a signal detected for DFS and does not require an instruction from the BBU 2 to select the frequency, the control unit 63 between the BBU 2 and the RRU 3 for DFS. The control performed in is simplified.
  • FIG. 25 shows the flow of DFS processing (autonomous reception level measurement processing) in RRU2 in Chapter 4.
  • the control unit (CPU) 63 determines a frequency to check whether it is a free frequency, and gives an instruction to change the frequency of the reception local oscillator 55 according to the determined frequency. (Step S1).
  • the reception local oscillator 55 that has received the frequency change instruction from the control unit 63 changes the frequency in accordance with the instruction (step S2).
  • the control unit (CPU) 63 acquires the reception signal level detected by the detector 61 after the reception local oscillator 55 changes the frequency, and records it in the reception signal level table T shown in FIG. 26 (step S3). ).
  • the received signal level table is stored in a memory (not shown) included in the RRU.
  • the determination of whether or not each frequency is free may be performed on the BBU2 side, but by performing on the RRU3 side as in the present embodiment, the processing burden on the BBU2 side can be reduced.
  • Step S5 the control unit 63 performs a process of collectively transmitting the contents of the reception signal level table T (information on the detection result) to the BBU 2.
  • the control unit 63 performs processing for collectively transmitting the contents of the reception signal level table T to the BBU 2, so that it is not necessary to transmit the result to the BBU 2 side every time the reception level is detected. Therefore, the control performed between BBU2 and RRU3 is simplified.
  • the contents of the table T are transmitted when there is an inquiry from the BBU 2, but even if there is no inquiry from the BBU 2, the RRU 3 side voluntarily transmits the contents of the table T. Good.
  • the control unit 63 determines the frequency to be checked next. Determine (step S1) and repeat the subsequent processing. Even if the reception level table T is created once, it is updated many times. Therefore, the reception level table T shows the latest frequency vacancy information.
  • the control unit 63 can determine the frequency in the order shown in the table T of FIG. 26 (for example, in order from the top), but other methods (for example, , Random).
  • a frequency range (search frequency range) to be confirmed as to whether or not it is a free frequency and / or a reception level threshold for determining that it is a free frequency is set in advance in RRU. These pieces of information may be given to the RRU 3 from the BBU 2 side.
  • the RRU 3 includes a receiver for receiving a signal from another radio base station apparatus, separately from the receiver for the original communication with the terminal apparatus, an arbitrary timing is provided. Thus, reception signal level detection for DFS can be performed.
  • a receiver for receiving a signal from a terminal device is used for level detection of a received signal from another radio base station device as shown in FIG. 24, a frequency different from the communication frequency with the terminal device. Will be received. For this reason, it is necessary to stop the normal reception and switch the frequency to measure the received signal level during a part of the reception time from the terminal device.
  • FIG. 27A illustrates an image of a “detection section” in which reception from a terminal apparatus is suspended and a received signal level from another base station apparatus is detected during signal reception from the terminal apparatus in the FDD scheme.
  • FIG. 27B shows an image of a “detection section” in the TDD scheme.
  • T indicates a transmission radio frame
  • R indicates a reception radio frame.
  • one reception radio frame R or one transmission radio frame is a radio frame
  • a radio frame is a combination of one transmission radio frame T and one reception radio frame R. is there.
  • the tail part of the received radio frame is set as a detection section.
  • the control unit 63 switches the reception frequency at the start of this detection interval, measures the reception level in a desired frequency channel, and then switches the frequency to the normal reception frequency channel.
  • the start timing of the detection section may be notified from the BBU2 to the RRU3 side, but the RRU3 autonomously grasps the detection section timing in order to reduce the processing load of the BBU2. Is preferred.
  • the control unit 63 determines the timing at which the set detection section is located in real time. I can grasp it. That is, the control unit 63 specifies the timing of the detection section by specifying the timing of the received radio frame.
  • the detection interval timing can be specified as follows when the transmission interface between the BBU 2 and the RRU 3 is the CPRI.
  • the CPRI frame exchanged between BBU2 and RRU3 is “CPRI Specification V4.1” ⁇ http: // www. cpri. info / downloads / CPRI_v_4_1_2009-02-18. According to pdf>, it is as shown in FIG.
  • the CPRI frame has a length of 10 ms per frame.
  • One CPRI frame (CPRI 10 ms frame) is composed of 150 hyperframes.
  • One hyper frame is composed of 256 basic frames.
  • the length T of one word is 8 bits (1 byte). In CPRI, 16-bit, 32-bit, 40-bit, 64-bit, 80-bit, etc. are defined as the length T of one word.
  • a digital IQ data frame transmitted between BBU2 and RRU3, such as a CPRI frame has a time length that is an integral multiple (including 1) of a radio frame, and is constant with respect to the radio frame. Synchronized with offset amount. For example, as shown in FIG. 29, both the CPRI frame and the LTE radio frame are 10 ms in length, and the offset amount is a fixed amount ⁇ t. Therefore, the control unit 63 can detect the start position of the radio frame based on the offset amount ⁇ t by detecting the boundary (start) of the CPRI frame transmitted from the BBU 2. If the start position of the radio frame can be detected, the real-time position of the detection section set in the received radio frame can be specified.
  • the timing of the radio frame detected as described above is the timing of the transmission radio frame transmitted from the BBU 2, but in the case of the FDD scheme, the reception radio frame usually coincides with the transmission radio frame. Therefore, the timing of the received radio frame is specified.
  • the transmission radio frame and the reception radio frame are alternately generated at predetermined time intervals in the radio frame. Therefore, if the timing of the transmission radio frame is specified.
  • the time after the predetermined time can be specified as the timing of the received radio frame.
  • OBSAI has a master frame having a period of 10 ms (“frame 0” in FIG. 30).
  • the wireless frame length is 5 ms, so two wireless frames enter the master frame.
  • the radio frame and the OBSAI transmission frame are synchronized with each other with a certain offset amount as in the case of CPRI. Therefore, similarly to the case of CPRI, the control unit 63 can identify the real-time position of the detection section in the radio frame by detecting the boundary of the master frame.
  • the master frame has a plurality of MGs (Massage Group), and has a synchronization code of K28.7 at the end of the master frame. Therefore, the control unit 63 can detect the boundary of the OBSAI frame by acquiring the OBSAI frame from the optical I / F 31 and detecting this synchronization code.
  • MGs Massage Group
  • the timing of the radio frame is detected based on the transmission frame from the BBU 2, but the reception radio frame is acquired from the reception digital signal processing unit 51 or from the output of the ADC 52 and included in the reception radio frame.
  • the timing of the received radio frame may be detected by detecting the synchronized signal.
  • FIG. 31 shows the RRU 3 according to the second embodiment in Chapter 4.
  • the RRU 3 in FIG. 31 differs from the RRU 3 in FIG. 24 in that it includes a plurality of receivers (also transmitters) and a plurality of reception local oscillators. 31 is the same as FIG. 24 in that the description is omitted.
  • the reception signal level from another radio base station apparatus needs to be switched for the reception frequency, so that reception for normal communication is required. Must be paused. Communication throughput decreases due to suspension of reception. And if it is going to suspend reception, the base station apparatus 1 must notify a terminal device to stop transmission. Since this notification is issued by the communication control unit 22 of the BBU2, it becomes a factor that increases the processing load of the BBU2.
  • the RRU 3 in FIG. 31 includes two receivers 50a and 50b. This is provided with a plurality of transmission / reception systems corresponding to a multi-antenna system (such as MIMO).
  • a part (at least one (second receiver 50b)) of a plurality of receivers 50a and 50b provided for the multi-antenna system is used in addition to wireless communication performed with a terminal device.
  • the reception signal level from other base station apparatuses is also used for detection, and the rest (first receiver 50a) is used for reception in normal wireless communication performed with the terminal apparatus.
  • the digital signal (baseband signal (reception IQ signal)) output from the reception digital signal processing unit 51b is replaced with zero (nothing). Signal). Therefore, a zero value is given to BBU2 as the output signal of the second receiver 50b in the detection interval.
  • BBU2 since reception processing is performed by combining signals from the two receivers 50a and 50b, communication with the terminal device can be continued even in the detection period. That is, when STC (Space Time Coding) is performed, even if the output from the second receiver 50b becomes zero for the BBU2, only the communication environment viewed from the second receiver 50b is degraded (for example, The wireless transmission path is cut off).
  • the BBU 2 does not need to perform processing such as blocking the received IQ signal from the RRU 3 in the signal level detection interval.
  • the second receiver 50b includes a signal switching unit 68.
  • the signal switching unit 68 is for switching between the case where the output of the reception digital signal processing unit 51b is selected and the case where the zero value is selected as the output of the second receiver 50b.
  • a command (reception IQ switching signal) is given to the signal switching unit 68 from the control unit 63.
  • the signal switching unit 68 outputs a zero value in the signal level detection section, and outputs the output of the reception digital signal processing unit 51b in other cases.
  • a first reception local oscillator 55-1 and a second reception local oscillator 55-2 are provided as reception local oscillators.
  • the first reception local oscillator 55-1 is an oscillator for normal communication performed with the terminal device
  • the second reception local oscillator 55-2 is an oscillator for detecting a received signal level from another base station device. It is.
  • the output of the first reception local oscillator 55-1 is given to the first receiver 50a and the switching unit 66 via the distributor 65.
  • the switching unit selectively outputs the output from the first reception local oscillator 55-1 and the output from the second reception local oscillator 55-2 given through the distributor 65 to the second receiver 50b. Give.
  • a command (high frequency switch switching signal) is given to the switching unit 66 from the control unit 63.
  • the switching unit 66 gives the output from the second reception local transmitter 55-2 to the mixer 54b of the second receiver 50b in the signal level detection section according to the command from the control unit 63, and otherwise
  • the output from the first reception local oscillator 55-1 is supplied to the mixer 54b of the second receiver 50b.
  • the frequency can be switched quickly. In other words, when trying to change the oscillation frequency of the oscillator itself, a certain amount of time is required, and the detection period is increased correspondingly, resulting in a decrease in communication throughput.
  • the frequency can be quickly changed by switching the two oscillators 55-1 and 55-2 for normal communication and reception signal level detection at the beginning and end of the detection interval.
  • FIG. 32 shows the RRU 3 according to the third embodiment in Chapter 4.
  • the fourth receiver 50d is a receiver used for measuring the received signal level from another base station apparatus.
  • the fourth receiver 50d of the third embodiment has the same configuration as the second receiver 50b of the second embodiment, and the first to third receivers 50a, 50b, 50c of the third embodiment The configuration is the same as that of the first receiver 50a of the embodiment. Further, in the third embodiment, points that are not described are the same as in the second embodiment.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Transmitters (AREA)

Abstract

L'invention concerne un circuit d'amplification (1) qui comporte: un amplificateur (2) qui amplifie la puissance de signaux d'entrée, une unité d'alimentation (3) qui applique une tension d'alimentation à l'amplificateur (2); un capteur de température (11) qui détecte la température de l'amplificateur (2); et une unité (8) déterminant la fréquence, qui détermine la fréquence de transmission des signaux d'entrée. De plus, le circuit d'amplification est pourvu d'une unité de commande (10) qui règle la tension d'alimentation de l'unité d'alimentation (3) et la puissance du signal des signaux d'entrée, sur la base de la température détectée par le capteur de température (11) et de la fréquence de transmission obtenue par l'unité (8) déterminant la fréquence.
PCT/JP2011/061866 2010-05-27 2011-05-24 Circuit d'amplification, dispositif de communication sans fil, système de communication sans fil et unité radio éloignée WO2011148939A1 (fr)

Applications Claiming Priority (8)

Application Number Priority Date Filing Date Title
JP2010121633A JP2011250164A (ja) 2010-05-27 2010-05-27 増幅回路、及びこれを用いた無線通信装置
JP2010-121633 2010-05-27
JP2010292965A JP2012142718A (ja) 2010-12-28 2010-12-28 無線通信システム及びリモートラジオユニット
JP2010-293483 2010-12-28
JP2010293483A JP2012142756A (ja) 2010-12-28 2010-12-28 無線通信装置
JP2010-292965 2010-12-28
JP2011-012014 2011-01-24
JP2011012014A JP2012156633A (ja) 2011-01-24 2011-01-24 無線通信装置及び無線通信システム

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WO2011148939A1 true WO2011148939A1 (fr) 2011-12-01

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Cited By (6)

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WO2014019493A1 (fr) * 2012-07-30 2014-02-06 华为终端有限公司 Dispositif, procédé et terminal mobile réduisant la consommation d'un amplificateur de puissance
CN103905345A (zh) * 2012-12-27 2014-07-02 华为技术有限公司 通道校正装置、方法及系统
WO2016003343A1 (fr) * 2014-07-04 2016-01-07 Telefonaktiebolaget L M Ericsson (Publ) Tête radio à distance et procédé associé
WO2016051463A1 (fr) * 2014-09-29 2016-04-07 株式会社日立国際電気 Dispositif de communications sans fil et dispositif de source d'alimentation
CN107659274A (zh) * 2017-10-26 2018-02-02 成都西井科技有限公司 具有压控衰减功能的功率放大模块
CN107733371A (zh) * 2017-10-26 2018-02-23 成都西井科技有限公司 高衰减值的压控衰减电路

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JP2007173982A (ja) * 2005-12-19 2007-07-05 Toshiba Corp 温度補償増幅器

Patent Citations (1)

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JP2007173982A (ja) * 2005-12-19 2007-07-05 Toshiba Corp 温度補償増幅器

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014019493A1 (fr) * 2012-07-30 2014-02-06 华为终端有限公司 Dispositif, procédé et terminal mobile réduisant la consommation d'un amplificateur de puissance
CN103580616A (zh) * 2012-07-30 2014-02-12 华为终端有限公司 一种功率放大器减耗装置、方法以及移动终端
CN103905345A (zh) * 2012-12-27 2014-07-02 华为技术有限公司 通道校正装置、方法及系统
WO2016003343A1 (fr) * 2014-07-04 2016-01-07 Telefonaktiebolaget L M Ericsson (Publ) Tête radio à distance et procédé associé
US9887714B2 (en) 2014-07-04 2018-02-06 Telefonaktiebolaget Lm Ericsson (Publ) Remote radio head and associated method
WO2016051463A1 (fr) * 2014-09-29 2016-04-07 株式会社日立国際電気 Dispositif de communications sans fil et dispositif de source d'alimentation
CN106575946A (zh) * 2014-09-29 2017-04-19 株式会社日立国际电气 无线通信装置以及电源装置
JPWO2016051463A1 (ja) * 2014-09-29 2017-08-10 株式会社日立国際電気 無線通信装置および電源装置
US9991849B2 (en) 2014-09-29 2018-06-05 Hitachi Kokusai Electric Inc. Wireless communication device and power source device
CN106575946B (zh) * 2014-09-29 2018-06-12 株式会社日立国际电气 无线通信装置
CN107659274A (zh) * 2017-10-26 2018-02-02 成都西井科技有限公司 具有压控衰减功能的功率放大模块
CN107733371A (zh) * 2017-10-26 2018-02-23 成都西井科技有限公司 高衰减值的压控衰减电路

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