JP6378227B2 - Point-to-point radio apparatus and communication control method - Google Patents

Description

  The present invention relates to a point-to-point radio apparatus and a communication control method, and more particularly to a point-to-point radio apparatus and a communication control method that perform multicarrier transmission using a spectrum mask for single carrier transmission.

  Examples of a fixed point-to-point wireless communication system in which a communication partner for wireless communication is set (fixed) are disclosed in Patent Document 1 and Patent Document 2.

  A fixed type point-to-point wireless communication system uses a frequency division multiplexing (FDD) system for bidirectional simultaneous communication (full-duplex communication). By using the FDD method, a pair of wireless devices facing each other on a point-to-point wireless line can suppress mutual frequency interference by dividing the radio frequency band used in the upstream and downstream directions. Thus, mutual communication can be performed efficiently.

  Here, it is assumed that one device of a pair of wireless devices facing each other on a point-to-point wireless line is represented as a wireless device A and the other device is represented as a wireless device B. In the FDD scheme, the frequency of radio waves that transmit signals from the wireless device A to the wireless device B is different from the frequency of radio waves that transmit signals from the wireless device B to the wireless device A. For this reason, the transmission of the signal from the wireless device A to the wireless device B and the reverse transmission of the signal from the wireless device B to the wireless device A can be simultaneously performed without causing frequency interference between them. .

  By the way, normally, when the wireless device A and the wireless device B perform wireless communication by the point-to-point FDD method, the wireless device A and the wireless device B use radio waves in radio frequencies in the upstream and downstream directions used for communication. Acquire the used licenses in pairs. In addition, the frequency interval between the frequency of the radio wave transmitted from the wireless device A to the wireless device B and the frequency of the radio wave transmitted from the wireless device B to the wireless device A is defined by the radio frequency standards of each country. Communication settings are set by a center frequency, a bandwidth, and a modulation / demodulation method, which are called carriers.

  A device that wirelessly transmits data to be transmitted using one carrier is referred to as a single carrier transmission wireless device, and a device that simultaneously transmits a plurality of carriers is referred to as a multicarrier transmission wireless device.

  For example, in the case of an FDD single carrier transmission wireless device, transmission is performed from a wireless device A to a wireless device B by a single carrier determined by a center frequency, a bandwidth, and a modulation method, and at the same time, a certain decision is made from the wireless device B to the wireless device A. It transmits with a single carrier keeping the specified frequency interval. At this time, the frequency interval of radio waves that can be used for a single carrier that is transmitted by radio is defined, for example, by ITU-R (International Telecommunication Union Radio communications sector).

  Furthermore, from the viewpoint of effective use of frequencies in a wireless communication system and constant protection of adjacent radio frequency bands, a spectrum mask that defines an allowable range of a radio transmission spectrum of a carrier is provided. Then, the radio apparatus must control transmission of carriers that fall within the spectrum mask while suppressing unnecessary radiation of the transmitter output. A spectrum mask that defines an allowable range of a radio transmission spectrum of a carrier used in a fixed type point-to-point radio apparatus is standardized by ETSI (European Telecommunications Standards Institute). For example, see Non-Patent Document 1 Section 4.2.4.

  In Patent Document 1, in a point-to-point wireless system using microwaves, millimeter waves, or the like, when switching a failed radio link, an unused wireless channel that can obtain good wireless quality is efficiently searched. Disclose technology.

  Patent Document 2 uses a redundant line for maintenance and control when returning from a one-way communication caused by a failure in one radio link when an FDD with a fixed frequency interval is used. A technique for safely switching between two-way wireless channels is disclosed.

  Furthermore, although it is not a fixed point-to-point wireless communication system, Patent Document 3 discloses a wireless communication capable of adaptively communicating in an optimal wireless mode (single carrier transmission, multicarrier transmission) according to the condition of the propagation path. A system is disclosed.

  Furthermore, Patent Document 4 discloses a multicarrier communication apparatus that can ensure the reliability of communication in an environment where an interference wave exists. This communication apparatus uses a transmission frequency band based on a noise level for each subcarrier, excluding subcarriers present in a frequency band in which an interference wave exists. At the time of reception, a usable frequency band is selected from each pass frequency band of the bandpass filter, and any one frequency band is designated as a use frequency band at the time of reception.

  Note that the communication devices disclosed in Patent Literature 3 and Patent Literature 4 are wireless devices using an OFDM (Orthogonal Frequency Division Multiplexing) system.

JP-A-2015-177497 JP-A-2015-177498 JP 2012-019425 A JP 2010-004469 A

ETSI EN 302 217-2-2 V2.1.1 (2013-07), Fixed Radio Systems; Characteristics and requirements for point-to-point equipment and antennas; Part 2-2: Digital systems operating in frequency bands where frequency co-ordination is applied; Harmonized EN covering the essential requirements of article 3.2 of the R & TTE Directive

  A fixed point-to-point wireless device is a device that is mainly licensed for single carrier transmission. The fixed point-to-point wireless device is hereinafter referred to as a point-to-point wireless device.

  When a point-to-point wireless apparatus licensed by single carrier transmission is shared by a plurality of users, the data of each user is multiplexed and then wirelessly transmitted using a single carrier.

  In the case of single carrier transmission, if fading, adjacent channel interference, etc. occur on the propagation path for a single carrier in which multiple user data are multiplexed, it will affect the transmission quality degradation and communication disconnection for all users. Will affect. Also, depending on the user, there is a case where it is desired to increase a transmission capacity for a channel to be used and a case where it is desired to ensure transmission quality, and a point-to-point wireless device based on single carrier transmission cannot simultaneously satisfy different user requests.

  The ETSI EN302 217-2-2 standard of Non-Patent Document 1 is a standard related to a spectrum mask that defines a radio transmission spectrum of single carrier transmission by such a point-to-point radio apparatus.

  In recent years, the ETSI EN302 217-2-2 standard has added a standard for using a spectrum mask defined for conventional single carrier transmission in multicarrier transmission. For this, provisions for making single carrier transmission multi-carrier so as not to affect existing transmission are added. As a result, even with the ETSI EN302 217-2-2 standard applied to point-to-point wireless devices, it is possible to provide a wireless device that uses a radio frequency band in multicarrier transmission.

  In the ETSI EN302 217-2-2 standard, the spectrum mask defined in the conventional radio transmission spectrum during single carrier transmission is also applied to the radio transmission spectrum during multicarrier transmission. For example, when multicarrier transmission is performed using two subcarriers, it is required to adjust the transmission level deviation between the two subcarriers within a predetermined value or to adjust the bandwidth to be within the side mask. Yes. That is, when a single-carrier transmission point-to-point wireless device is converted to multi-carrier transmission, it is necessary to perform multi-carrier transmission while satisfying the radio transmission spectrum specification at the time of single-carrier transmission.

  However, the ETSI EN302 217-2-2 standard only stipulates the radio transmission spectrum specification for making the point-to-point radio apparatus into multicarrier transmission, and there is no disclosure regarding a specific means for realizing it. Therefore, it is desired to develop a point-to-point wireless device that can adjust the transmission output level and bandwidth for each subcarrier that performs multicarrier transmission and that can perform multicarrier transmission satisfying the radio transmission spectrum regulations during single carrier transmission. .

  Patent Documents 1 and 2 disclose techniques related to a point-to-point wireless system, but there is no disclosure related to a point-to-point wireless apparatus that can perform multicarrier transmission satisfying the wireless transmission spectrum specification at the time of single carrier transmission.

  Moreover, although patent document 3 and patent document 4 disclose the technique regarding a multicarrier communication apparatus, all are techniques on the premise of OFDM system. Therefore, these Patent Documents 3 and 4 also do not disclose a point-to-point wireless apparatus that can perform multicarrier transmission while satisfying the wireless transmission spectrum specification at the time of single carrier transmission.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a point-to-point wireless apparatus and a communication control method capable of performing multicarrier transmission while satisfying the wireless transmission spectrum specification at the time of single carrier transmission. There is.

  In order to achieve the above object, a point-to-point wireless device according to an aspect of the present invention can be arranged to satisfy a predetermined single-carrier transmission radio transmission spectrum specification in accordance with the number of subcarriers for multicarrier transmission. A subcarrier generation unit corresponding to each subcarrier for multicarrier transmission, which generates a subcarrier converted into a modulated wave in a modulation intermediate frequency band having a center frequency and a bandwidth, and each of the subcarrier generation units outputs the subcarrier Level increase / decrease calculation means for instructing the subcarrier generation means to increase / decrease the signal level of the modulated wave so that the signal level of the subcarrier satisfies the predetermined radio transmission spectrum specification of the single carrier transmission. And the signal level of each of the subcarriers is the radio transmission spectrum. Multi-carrier combining means for combining with a multi-carrier and frequency-converting to a radio intermediate frequency band and outputting when the regulation is satisfied, and the multi-carrier in the wireless intermediate frequency band output by the multi-carrier combining means And a wireless transmission means for converting and outputting the transmission signal.

  Also, the communication control method according to another aspect of the present invention is a modulation having a center frequency and a bandwidth that can be arranged satisfying a predetermined radio transmission spectrum specification for single carrier transmission according to the number of subcarriers to be transmitted by multicarrier. Generate subcarriers converted to modulated waves in the intermediate frequency band, so that the signal level of each of the subcarriers for multi-carrier transmission satisfies the predetermined radio transmission spectrum specification for the predetermined single carrier transmission. Instructing to increase / decrease the signal level of the modulated wave, and when the signal level of each of the sub-carriers satisfies the wireless transmission spectrum specification, it is synthesized into a multi-carrier and frequency-converted to a wireless intermediate frequency band and output. The multi-carrier in the radio intermediate frequency band is converted into a radio frequency band transmission signal and output. It is characterized in.

  INDUSTRIAL APPLICABILITY The present invention can provide a point-to-point wireless apparatus and a communication control method that can perform multicarrier transmission while satisfying the wireless transmission spectrum specification during single carrier transmission.

1 is a block diagram illustrating a configuration of a point-to-point wireless device according to a first embodiment of the present invention. It is a flowchart which illustrates operation | movement of the communication control method which concerns on the 1st Embodiment of this invention. It is a block diagram which illustrates the structure of the point-to-point radio | wireless apparatus which concerns on the 2nd Embodiment of this invention. It is a block diagram which illustrates the structure by the side of the transmission of the multicarrier control part which comprises a point-to-point radio | wireless apparatus. It is a block diagram which illustrates the structure of the receiving side of the multicarrier control part which comprises a point-to-point radio | wireless apparatus. It is a figure which illustrates the radio | wireless transmission spectrum for demonstrating the difference of single carrier transmission and multicarrier transmission. It is a figure explaining the transmission level deviation between the subcarriers in the radio | wireless transmission spectrum by ETSI specification. It is a flowchart explaining the whole operation | movement of the increase / decrease control of the signal level of the subcarrier transmitted by multicarrier. FIG. 9 is a flowchart for explaining the operation of increasing / decreasing the output level of the modulation wave amplifier so as to satisfy the standard radio transmission spectrum specification in the operation of FIG. 8.

  Embodiments for carrying out the present invention will be described below in detail with reference to the drawings.

  The embodiment is an exemplification, and the disclosed apparatus and method are not limited to the configurations of the following embodiment. The reference numerals attached to the drawings are added as an example for helping understanding, and are not intended to be any limitation. Furthermore, the direction of the arrow in the drawing shows an example, and does not limit the direction of the signal between the blocks.

(First embodiment)
The first embodiment will be described with reference to FIGS. 1 and 2.

  FIG. 1 is a block diagram illustrating the configuration of a point-to-point wireless apparatus according to the first embodiment of the present invention.

  The point-to-point radio apparatus 10 according to the first embodiment includes a subcarrier generation unit 11, a level increase / decrease calculation unit 12, a multicarrier combination unit 13, and a radio transmission unit 14 corresponding to each subcarrier that performs multicarrier transmission. It has become.

  The subcarrier generating means 11 converts the modulated wave into a modulated intermediate frequency band having a center frequency and a bandwidth that can be arranged satisfying a predetermined radio transmission spectrum specification for single carrier transmission according to the number of subcarriers to be transmitted by multicarrier. Generated subcarriers.

  The level increase / decrease calculation unit 12 is configured to make the subcarrier generation unit 11 so that the signal level of the subcarrier output from each of the subcarrier generation units 11 satisfies a predetermined radio transmission spectrum specification for single carrier transmission. Is instructed to increase or decrease the signal level of the modulated wave.

  When the signal level of each subcarrier satisfies the wireless transmission spectrum specification, the multicarrier combining unit 13 combines the multicarrier with the multicarrier, converts the frequency to the wireless intermediate frequency band, and outputs the result.

  The wireless transmission means 14 converts the multicarrier in the wireless intermediate frequency band output from the multicarrier combining means 13 into a transmission signal in the wireless frequency band and outputs it.

  The wireless intermediate frequency band is also referred to as an IF (Intermediate Frequency) band, and the wireless frequency band is also referred to as an RF (Radio Frequency) band.

  By configuring as described above, when the subcarriers output from each subcarrier generating unit 11 are combined into multicarriers, the signal spectrum can satisfy the predetermined radio transmission spectrum specification for single carrier transmission. . Therefore, the point-to-point wireless apparatus 10 of the present embodiment functions as a point-to-point wireless apparatus that can perform multicarrier transmission while satisfying the wireless transmission spectrum specification at the time of single carrier transmission.

  FIG. 2 is a flowchart illustrating the operation of the communication control method according to the first embodiment of the invention. In the communication control method according to the first embodiment, the point-to-point wireless device operates as follows.

  A subcarrier converted into a modulated wave in the modulation intermediate frequency band is generated. At this time, according to the number of subcarriers for multicarrier transmission, a subcarrier is set with a center frequency and a bandwidth that can be arranged satisfying a predetermined radio transmission spectrum specification for single carrier transmission (S101).

  Increase / decrease control of the signal level of the modulated wave is performed so that the signal level of each subcarrier for multicarrier transmission satisfies a predetermined radio transmission spectrum specification for single carrier transmission (S102).

  When the signal level of each subcarrier satisfies the radio transmission spectrum specification, the subcarrier is combined with a multicarrier, frequency-converted to a radio intermediate frequency band, and output (S103).

  The multicarrier in the radio intermediate frequency band is converted into a radio frequency band transmission signal and output (S104).

  By operating as described above, when subcarriers are combined into multicarriers, the signal spectrum can satisfy a predetermined radio transmission spectrum specification for single carrier transmission. Therefore, the communication control method according to the present embodiment can provide a communication control method capable of performing multicarrier transmission while satisfying the radio transmission spectrum specification during single carrier transmission.

(Second Embodiment)
The second embodiment will be described in detail with reference to FIGS.

[Description of configuration]
FIG. 3 is a block diagram illustrating the configuration of a point-to-point wireless apparatus according to the second embodiment of the present invention.

  The point-to-point wireless device 20 according to the second embodiment is exemplified by a microwave relay device that establishes a wireless link with a facing wireless device using microwaves or millimeter waves. In addition, the point-to-point wireless device 20 uses the FDD method in order to perform bidirectional simultaneous communication (full duplex communication) with a facing wireless device. In the FDD system, in order to suppress interference due to wraparound between radio frequency transmission and reception, the FDD system is operated with a constant frequency interval between the radio transmission frequency and the radio reception frequency.

  The point-to-point radio apparatus 20 includes an interface unit 21, a multicarrier control unit 22, and a radio transceiver 23.

  The interface unit 21 converts a signal in a data format of a user side device standard input from a user side device (not shown) into a baseband signal (unipolar 0/1 data) handled by the wireless device. Conversely, the baseband signal handled by the wireless device is converted into a signal in the data format of the user device standard that is output to the user device. For example, when the user side device and the point-to-point wireless device 20 are connected by a LAN (Local Area Network), the signal in the data format of the user side device standard is a LAN standard signal.

  At the time of transmission, the multicarrier control unit 22 individually modulates a user signal corresponding to each subcarrier to be transmitted by multicarrier, converts the frequency into a modulation signal in the modulation intermediate frequency band, performs signal increase / decrease processing, and subcarriers Generate. The multicarrier control unit 22 combines the generated plurality of subcarriers into a transmission signal in a multicarrier transmission form. Then, the transmission signal combined in the multicarrier transmission form is frequency-converted to a transmission signal (Txif) in the wireless intermediate frequency band (IF band) and output to the wireless transceiver 23.

  Further, at the time of reception, the multicarrier control unit 22 frequency-converts the IF band reception signal (Rxif) of the multicarrier transmission form input from the radio transceiver 23 into a demodulation intermediate frequency band reception signal. Then, the received signal is separated into subcarriers, and the separated subcarriers are individually demodulated to output a baseband received signal.

  At the time of transmission, the multicarrier control unit 22 performs waveform shaping so that the transmission signal of the combined multicarrier transmission form fits in a spectrum mask defined by the ETSI standard when each subcarrier is generated individually.

  At the time of transmission, the wireless transceiver 23 transmits a transmission signal (Txrf) for transmitting an IF band transmission signal (Txif) output from the multicarrier control unit 22 through a radio channel of a radio frequency band (RF band) designated by a license. ). Then, the transmission signal (Txrf) is wirelessly transmitted to the opposing wireless device via the antenna.

  On the other hand, at the time of reception, the wireless transceiver 23 receives an RF band reception signal (Rxrf) on the reception-side wireless channel for which the license is acquired in a pair. Then, after correcting the reception level fluctuation caused by the environmental fluctuation such as radio space fluctuation or rain, it is converted into an IF band reception signal (Rxif) and output to the multicarrier control unit 22.

  As described above, the point-to-point radio apparatus 20 of the present embodiment uses the multicarrier control unit 22 to perform frequency conversion between the baseband and the modulation / demodulation intermediate frequency band, Frequency conversion to and from the IF band is performed. Then, the radio transceiver 23 performs frequency conversion between the IF band and the RF band. Here, the subcarriers corresponding to the user's transmission signal are waveform-shaped and synthesized in the modulation intermediate frequency band so as to be within a spectrum mask that defines the allowable range of the radio transmission spectrum transmitted in the RF band.

  The subcarrier generating unit 11, the level increase / decrease calculating unit 12 and the multicarrier combining unit 13 of the first embodiment correspond to the multicarrier control unit 22 of the second embodiment. In particular, in FIG. 4 described later, the subcarrier unit 221 corresponds to the subcarrier generation unit 11, and the reference value storage unit 2231 and the level increase / decrease calculation unit 2232 in the common control unit 223 correspond to the level increase / decrease calculation unit 12. The synthesizer 2233 and the IF band frequency converter 2234 in the common controller 223 correspond to the multicarrier synthesizer 13. The wireless transmission unit 14 of the first embodiment corresponds to the wireless transceiver 23 of the second embodiment.

  The point-to-point wireless device 20 illustrated in FIG. 3 illustrates a case where two user signals of the user A and the user B are transmitted by multicarrier. Here, a transmission signal of user A is a transmission signal aT, and a transmission signal of user B is a transmission signal bT. Further, the received signal of the user A is the received signal aR, and the received signal of the user B is the received signal bR.

  4 and 5 are block diagrams each illustrating the configuration of the multicarrier control unit 22, FIG. 4 shows the configuration on the transmission side, and FIG. 5 shows the configuration on the reception side.

  The multicarrier control unit 22 includes a subcarrier unit that performs processing for each subcarrier that performs multicarrier transmission, and a common control unit 223 that controls each subcarrier unit in common.

  Here, since the two user signals of the user A and the user B are transmitted by multicarrier, the subcarrier unit a221 that processes the user A signal and the subcarrier unit b222 that processes the user B signal are included. .

  That is, FIG. 4 illustrates a configuration in which the subcarrier unit a221 processes subcarriers for the transmission signal aT of the user A, and the subcarrier unit b222 processes subcarriers for the transmission signal bT of the user B. FIG. 5 illustrates a configuration in which the subcarrier unit a221 processes a subcarrier for the received signal aR of the user A, and the subcarrier unit b222 processes a subcarrier for the received signal bR of the user B.

  In FIG. 4, the common control unit 223 adjusts the signal level of the subcarriers individually modulated by the subcarrier unit a221 and the subcarrier unit b222, and wireless transmission / reception is performed by combining the subcarriers adjusted in signal level. The structure output to the machine 23 is shown. The combined transmission signal in the multicarrier transmission form is converted to an IF band frequency and output to the radio transceiver 23.

  Further, FIG. 5 shows a configuration in which the common control unit 223 inputs an IF band signal from the radio transceiver 23 and distributes it to the subcarrier unit a221 and the subcarrier unit b222 as a received signal in the demodulation intermediate frequency band.

  The configuration of the multicarrier control unit 22 will be described in detail with reference to FIGS. 4 and 5.

  Referring to FIG. 4, the subcarrier unit a221 inputs the transmission signal aT of the user A, and the subcarrier unit b222 inputs the transmission signal bT of the user B, and individually modulates the signal, shapes the waveform, and signals Level adjustment is performed to generate subcarriers.

  The structure will be described with reference to the subcarrier part a221.

  The subcarrier unit a221 includes a modulation unit 2211, a modulation wave frequency conversion unit 2212, a modulation wave amplifier 2213, and a detector 2214.

  The modulation unit 2211 receives the transmission signal aT (baseband signal) of the user A output from the interface unit 21 which is the preceding apparatus shown in FIG. 3, modulates the signal with an appropriate modulation method, and modulates the signal as an analog signal. Is output.

  The modulation unit 2211 is configured so that a modulation method according to a user's request can be appropriately selected and set. For example, a 4PSK (Quadrature Phase Shift Keying) method or a QAM (Quadrature Amplitude Modulation) method can be selected. In the case of the QAM system, 16QAM / 32QAM / 64QAM / 128QAM / 256QAM / 1024QAM / 2048QAM can be selected according to the number of modulation levels. Further, the information may be fed back to the transmission side in accordance with the reception state on the reception side, and the configuration may be such that adaptive modulation that adaptively changes the modulation scheme is possible.

  The modulation wave frequency conversion unit 2212 includes a frequency conversion circuit and a band pass filter, and shapes the modulation signal into a modulation wave in a modulation intermediate frequency band having a predetermined center frequency and bandwidth. In FIG. 4, the center frequency is set to f1.

  Modulated wave amplifier 2213 controls to increase or decrease the signal level of the waveform-shaped modulated wave output from modulated wave frequency converter 2212. Here, as described later, increase / decrease control of the output level of modulated wave amplifier 2213 is performed based on an instruction value from common control unit 223 so that the subcarrier satisfies a predetermined radio transmission spectrum specification.

  The detector 2214 measures the signal level of the modulated wave output from the modulated wave amplifier 2213 and outputs it to the common control unit 223.

  The above is the configuration of the subcarrier part a221, but the subcarrier part b222 has the same configuration. That is, the subcarrier unit b222 includes a modulation unit 2221, a modulation wave frequency conversion unit 2222, a modulation wave amplifier 2223, and a detector 2224.

  The subcarrier unit b222 receives the transmission signal bT of the user B and generates a subcarrier for the user B. Therefore, the modulation unit 2221 appropriately selects and sets a modulation method according to the request of the user B. Further, the modulated wave frequency converter 2222 shapes the waveform as a modulated wave having a center frequency of f2 and a predetermined bandwidth.

  Modulated wave amplifier 2223 increases or decreases the signal level of the waveform-shaped modulated wave output from modulated wave frequency converter 2222 based on the instruction value from common controller 223.

  The detector 2224 measures the signal level of the modulated wave output from the modulated wave amplifier 2223 and outputs it to the common control unit 223.

  The waveform shaping executed by the modulation wave frequency conversion unit 2212 of the subcarrier unit a221 and the modulation wave frequency conversion unit 2222 of the subcarrier unit b222 is centered so that the combined modulation wave satisfies a predetermined radio transmission spectrum specification. Frequency and bandwidth are set. This will be described later.

  The modulated waves output from the modulated wave amplifiers 2213 and 2223 will be described hereinafter as subcarriers.

  Next, the configuration of the common control unit 223 will be described.

  The common control unit 223 includes a reference value storage unit 2231, a level increase / decrease calculation unit 2232, a combiner 2233, and an IF band frequency conversion unit 2234.

  The reference value storage unit 2231 and the level increase / decrease calculation unit 2232 are configured to output an instruction value for increase / decrease control of the output level of the modulated wave amplifier of each subcarrier unit. That is, an instruction value for increasing / decreasing the signal level of the corresponding subcarrier is output to each of the modulated wave amplifier 2213 of the subcarrier unit a221 and the modulated wave amplifier 2223 of the subcarrier unit b222.

  The reference value storage unit 2231 stores in advance information related to a predetermined radio transmission spectrum specification and information related to a modulation scheme based on an operation contract condition with a user. Further, the reference value storage unit 2231 inputs the signal level of the subcarrier that is measured by the detector of each subcarrier unit and controlled to increase or decrease by the modulation wave amplifier. That is, the subcarrier signal levels, which are the outputs of the modulated wave amplifier 2213 and the modulated wave amplifier 2223, respectively output from the detector 2214 of the subcarrier unit a221 and the detector 2224 of the subcarrier unit b222 are input.

  The level increase / decrease calculation unit 2232 calculates the signal increase / decrease level by verifying the difference between the information stored in the reference value storage unit 2231 in advance and the signal level of each subcarrier input to the reference value storage unit 2231, and provides the necessary modulation wave amplifier. An instruction to increase or decrease the output level is issued. That is, an instruction value for increasing / decreasing the signal level of a predetermined subcarrier is output to the modulated wave amplifier 2213 or the modulated wave amplifier 2223 so that the predetermined radio transmission spectrum specification is satisfied when combined as a multicarrier. .

  This modulation wave amplifier, each detector, reference value storage unit 2231 and level increase / decrease calculation unit 2232 increase / decrease control of the signal level of the subcarrier is within the range of allowable values in which the signal level of each subcarrier is defined in advance. Repeat until the proper value is reached.

  When the level increase / decrease calculation unit 2232 determines that the signal level of each subcarrier has reached an appropriate value within a predetermined allowable range, the subcarrier output from each modulation wave amplifier is output by the combiner 2233. It is synthesized as a multi-carrier. At this time, the level increase / decrease calculation unit 2232 stores the signal level of each subcarrier that has reached an appropriate value in the reference value storage unit 2231.

  The synthesizer 2234 synthesizes each subcarrier whose signal level is within a predetermined allowable range into a multicarrier, and the IF band frequency conversion unit 2234 converts the multicarrier into an IF band frequency and outputs it.

  The combiner 2234 combines the subcarriers output from the subcarrier unit a221 and the subcarrier unit b222, extracts only the effective component as data in the combined signal band by a bandpass filter (not shown), and generates an unnecessary wave. Perform waveform shaping to remove components.

  The IF band frequency conversion unit 2234 converts the frequency of the synthesized multicarrier into an IF band transmission signal (Txif) using the f3 signal, and an effective component within the signal band of the transmission signal (Txif) using a bandpass filter (not shown). To extract unnecessary wave components.

  The transmission signal (Txif) output from the IF band frequency converter 2234 is input to the wireless transceiver 23 shown in FIG. The wireless transmitter / receiver 23 converts the input signal into an RF band transmission signal (Txrf) designated by the license, and wirelessly transmits the signal to the opposite wireless device via the antenna.

  Next, the configuration of the reception side of the multicarrier control unit 22 will be described with reference to FIG.

  The multicarrier control unit 22 converts the IF band received signal (Rxif) into a demodulated intermediate frequency band received signal by the common control unit 223, demultiplexes each subcarrier transmitted by the multicarrier, and outputs a corresponding subcarrier. It is distributed to the carrier part a221 and the subcarrier part b222.

  The subcarrier unit a221 and the subcarrier unit b222 demodulate the corresponding subcarriers, and output the received signal aR and the received signal bR in the baseband to the interface unit 21 shown in FIG.

  Referring to FIG. 5, the common control unit 223 of the multicarrier control unit 22 includes an IF band frequency conversion unit 2236 and a duplexer 2235.

  The IF band frequency conversion unit 2236 receives the IF band reception signal (Rxif) of the multicarrier transmission form received from the wireless transceiver 23 shown in FIG. At this time, an effective component of the received signal (Rxif) is extracted by a bandpass filter (not shown), and unnecessary wave components are removed.

  The IF band frequency converter 2236 converts the IF band received signal (Rxif) into a demodulated intermediate frequency band received signal using the f13 signal, and removes an unnecessary wave generated by the frequency conversion by a bandpass filter (not shown).

  The demultiplexer 2235 demultiplexes the reception signal in the demodulation intermediate frequency band generated by the IF band frequency conversion unit 2236 into each subcarrier transmitted by multicarrier, and distributes it to the corresponding subcarrier unit.

  The subcarrier unit a221 includes a BPF (band pass filter) 2218, a demodulated wave amplifier 2217, a demodulated wave frequency converter 2216, and a demodulator 2215.

  From the demodulated subcarrier (demodulated wave) input to the subcarrier part a221, a corresponding demodulated wave signal is extracted by the BPF 2218, and the demodulated wave amplifier 2217 performs signal level amplification of the demodulated wave.

  The demodulated wave frequency converter 2216 converts the demodulated wave in the demodulated intermediate frequency band, which has been amplified in signal level, into a demodulated wave in the baseband using the f11 signal. The demodulated wave frequency-converted by the demodulated wave frequency converter 2216 is input to the demodulator 2215 after unnecessary waves generated by the frequency conversion are deleted by a bandpass filter (not shown).

  Demodulation section 2215 demodulates the demodulated wave and outputs the received signal aR of baseband user A by the same demodulation scheme as the modulation scheme set in the corresponding subcarrier modulation section of the opposite radio apparatus.

  The subcarrier unit b222 also includes a BPF 2228, a demodulated wave amplifier 2227, a demodulated wave frequency converting unit 2226, and a demodulating unit 2225 having the same configuration as described above. The demodulated wave frequency conversion unit 2226 uses the f12 signal and the demodulation method of the demodulation unit 2225 is the same as the modulation method set in the modulation unit of the corresponding subcarrier of the opposite radio apparatus. The difference is that the B reception signal bR is output.

  In addition, the receiving-side configuration of the subcarrier unit a221 and the subcarrier unit b222 does not have a function of increasing / decreasing the signal level of the subcarrier, but instead has an automatic level control function for making the signal level of the demodulator constant. have.

  The above is the configuration of the point-to-point wireless apparatus according to the present embodiment.

[Single-carrier transmission and multi-carrier transmission]
Next, the difference between single carrier transmission and multicarrier transmission will be mentioned.

  FIG. 6 is a diagram illustrating a radio transmission spectrum for explaining the difference between single carrier transmission and multicarrier transmission.

  6A illustrates the radio transmission spectrum of the transmission signal (Txif) in the single carrier transmission form, and FIG. 6B illustrates the radio transmission spectrum of the transmission signal (Txif) in the multicarrier transmission form.

  As shown in FIG. 6A, the transmission signal (Txif) in the single carrier transmission form includes a multiplexed signal (aT + bT) in which the transmission signal aT of the user A and the transmission signal bT of the user B are multiplexed. . A point-to-point wireless apparatus in a single carrier transmission form is configured to multiplex a transmission signal aT and a transmission signal bT at an interface unit and transmit a single carrier obtained by modulating the multiplexed signal. Of course, at the time of reception, a single carrier is demodulated, and two multiplexed signals are separated and distributed to each user.

  For this reason, in the single carrier transmission mode in which a plurality of signals are multiplexed, different demands for each user for the channel to be used cannot be fulfilled. For example, a user may desire a large transmission capacity of a wireless line to be used. Conversely, a certain user may desire to secure transmission quality rather than transmission capacity.

  On the other hand, in the multicarrier transmission mode, as shown in FIG. 6B, the used radio frequency band is divided for each user, and the user data is wirelessly transmitted as subcarriers for each frequency band obtained by dividing the radio band. . Therefore, in the multicarrier transmission mode, it is possible to construct a radio channel corresponding to different individual requests for each subcarrier constituting the multicarrier.

  The point-to-point wireless device according to the present embodiment individually has a condition (parameter 1) that gives priority to a large transmission capacity of a radio channel and a condition (parameter 2) that gives priority to resistance to transmission quality degradation due to fading, frequency interference, etc. A configuration to be realized is provided.

  In addition, when parameters are mixed, it is possible to set which parameter is prioritized to construct subcarrier transmission. For users who have parameter 1> 2 as a priority condition, a subcarrier transmission set to realize wireless transmission capable of securing a transmission capacity is constructed. On the other hand, for the users who have the parameter 1 <2 as a priority condition, a subcarrier transmission set to realize wireless transmission capable of securing transmission quality from the transmission capacity is constructed.

[Set subcarrier center frequency, bandwidth and modulation method]
In the following description, the spectrum mask that defines the allowable range of the wireless transmission spectrum of the carrier will be referred to as a wireless transmission spectrum specification or a spectrum mask.

  In the ETSI EN302 217-2-2 standard, the same spectrum mask is used for the radio transmission spectrum of the single carrier transmission mode shown in FIG. 6A and the radio transmission spectrum of the multicarrier transmission mode shown in FIG. . In other words, a signal obtained by synthesizing a single carrier as multicarrier transmission needs to satisfy the radio transmission spectrum specification of single carrier transmission of the ETSI EN302 217-2-2 standard.

  The radio transmission spectrum shown in FIG. 6B is a transmission signal (Txif) at the time of multicarrier transmission in which two subcarriers output by waveform shaping by the subcarrier part a221 and the subcarrier part b222 in FIG. 4 are combined. Is shown.

  In multi-carrier transmission, an interference guard frequency band is provided between subcarriers and the center frequency and bandwidth of each subcarrier are set so that the combined subcarriers adjacent to each other are not overlapped in a specified spectrum mask. There is a need.

  The center frequency and bandwidth are set by the modulation wave frequency conversion unit 2212, the frequency conversion circuit of the modulation wave frequency conversion unit 2222, and the bandpass filter shown in FIG.

  That is, for the subcarrier of the signal aT shown in FIG. 6B, the center frequency is set by the f1 signal input to the frequency conversion circuit of the modulation wave frequency conversion unit 2212, and the bandwidth fa is set by the bandpass filter. 6B, the center frequency is set by the f2 signal input to the frequency conversion circuit of the modulation wave frequency conversion unit 2222, and the bandwidth fb is set by the band pass filter.

  Then, the subcarriers for which the increase / decrease control for adjusting the respective signal levels by the modulation wave amplifier 2213 and the modulation wave amplifier 2223 are combined into a multicarrier, and converted into a transmission signal (Txif) by the IF band frequency conversion unit 2234.

  Further, the modulation unit 2211 and the modulation unit 2221 are configured so that a modulation method according to a user's request can be appropriately selected and set, and according to a priority condition (parameter 1 / parameter 2) related to a transmission environment desired by the user. The modulation method is selected and set.

  For a user who prioritizes securing the transmission capacity of parameter 1, for example, 2048QAM is selected as the modulation scheme because the modulation multi-level number is large and the transmission efficiency is high. That is, in the setting operation in which priority is given to securing the transmission capacity, a modulation method capable of securing the maximum transmission capacity on a clear day is set in the modulation unit instead of allowing a data error during rain.

  On the other hand, for a user who prioritizes securing the transmission quality of parameter 2, for example, 4PSK, which has a transmission quality degradation tolerance even when the propagation condition deteriorates, is selected as the modulation method and set in the modulation unit.

  Note that the receiving unit of the opposite wireless device also sets the demodulation method and bandwidth in advance according to the parameter 1 / parameter 2 of the priority condition related to the transmission environment desired by the user in order to realize the wireless transmission desired by each user individually. Keep it.

  The center frequency, bandwidth, and modulation method are set in advance with the opposing wireless device before starting operation.

[Setting subcarrier center frequency and bandwidth according to parameters]
Next, the setting of the subcarrier center frequency and bandwidth according to the above-described parameter 1 / parameter 2 will be described.

  In multicarrier transmission, it is not possible to set an interference guard frequency band between subcarriers and set the center frequency and bandwidth of each subcarrier so that adjacent subcarriers do not overlap each other in the specified spectrum mask. As described above. This is to prevent adjacent interference between subcarriers by providing an interference guard frequency band and to ensure transmission quality in multicarrier transmission. This transmission quality is evaluated by C / N (Carrier-Noise ratio).

  When allocating the subcarriers used by user A and user B within the same frequency band of the licensed radio frequency channel, the interference guard frequency band is usually at the center of the frequency obtained by equally dividing the frequency band. It only has to be provided.

  However, when the priority conditions regarding the transmission environment of parameter 1 / parameter 2 required by the users are different, the modulation schemes to be applied are different among users. As described above, for example, 2048QAM with high transmission efficiency is applied to a user who wants to secure transmission capacity using parameter 1 as a priority condition. For a user who wants to prioritize securing transmission quality using parameter 2 as a priority condition, for example, 4PSK having a transmission quality degradation tolerance is applied.

  As the modulation scheme becomes multi-valued, the interference guard frequency bandwidth necessary for securing a required C / N in the modulated wave modulated by the modulation scheme increases. On the contrary, since the required C / N in the modulated wave modulated by the low multilevel modulation method is small, the necessary interference guard frequency bandwidth is small. Thus, when subcarriers modulated by different modulation schemes coexist in the same radio transmission spectrum, it is necessary to ensure an interference guard frequency band with a margin corresponding to the modulation scheme.

  For example, when the interference guard frequency band is set such that only the required C / N of a certain modulation scheme can be secured, a modulation scheme having a larger number of multiple values than that modulation scheme cannot be used. Therefore, in such a case, it is necessary to apply a modulation method having a multi-value number smaller than that modulation method. This means that it is necessary to secure the interference guard frequency bandwidth so that the required C / N for the subcarrier by the high-level modulation scheme can be secured preferentially. In such a case, for example, an interference guard frequency band in which C / N required in the 2048QAM modulation method using the maximum multi-level number can be secured may be set in advance.

  The center frequency and bandwidth of the subcarrier corresponding to such parameters are allocated by the modulation wave frequency conversion unit 2212 of the subcarrier part a221 and the modulation wave frequency conversion part 2222 of the subcarrier part b222.

  That is, a modulation scheme suitable for a request based on an operation contract between the user A and the user B is set in the modulation unit 2211 and the modulation unit 2221. Then, an interference guard frequency bandwidth capable of securing C / N required for each modulation method is obtained. The center frequency and the bandwidth are allocated in the modulation wave frequency conversion unit 2212 and the modulation wave frequency conversion unit 2222 so that the interference guard frequency band with more severe conditions can be set. The center frequency is set by the f1 signal and the f2 signal, and the bandwidth can be set by the characteristics of the bandpass filter. These are set at the time of initial setting based on the operating conditions of the wireless device.

  Also, when using an adaptive modulation scheme, it is necessary to set the interference guard frequency bandwidth based on the C / N securing requirements of each modulation scheme so as to be able to cope with adaptively changing modulation schemes. . For example, when 4PSK and 16/32/64/128/256/1024 / 2048QAM can be adaptively modulated according to the state of the receiving side, the interference that can secure the C / N required by the 2048QAM modulation scheme with the maximum multi-level number A guard frequency band may be set in advance.

  Needless to say, the f11 signal and the f12 signal are also set to frequencies in consideration of the interference guard frequency band in the same manner as described above when demodulating by the opposing radio apparatus.

  The setting of the center frequency and bandwidth in consideration of the interference guard frequency band required according to the above modulation scheme is set in advance before the start of operation together with the opposing radio apparatus.

[Increase / decrease control of output level of modulated wave amplifier]
Next, increase / decrease control of the signal level of the subcarriers by the modulated wave amplifiers 2213 and 2223, the detectors 2214 and 2224, the reference value storage unit 2231 and the level increase / decrease calculation unit 2232 shown in FIG. 4 will be described in detail.

  As described above, the level increase / decrease calculation unit 2232 in FIG. 4 calculates the signal increase / decrease level by verifying the difference between the information stored in the reference value storage unit 2231 in advance and the signal level of each subcarrier input to the reference value storage unit 2231. To do. Then, the level increase / decrease calculation unit 2232 issues an output level increase / decrease instruction to the modulation wave amplifier 2213 or the modulation amplifier 2223. This increase / decrease control is repeated until the signal level of the combined subcarrier reaches an appropriate value within a range of allowable values defined in advance by a predetermined spectrum mask.

  The allowable value of the wireless transmission spectrum of the point-to-point wireless device is specified in the section 42.4 of the ETSI EN302 217-2-2 standard.

  FIG. 7 is a diagram for explaining a transmission level deviation between subcarriers in a radio transmission spectrum according to the ETSI standard. In the ETSI standard, it is required to adjust and control the transmission level deviation between subcarriers constituting a multicarrier within a predetermined value k1 (dB).

  The output level increase / decrease control for the modulation wave amplifier is to control the signal level of the subcarrier output from the corresponding modulation wave amplifier so that the transmission level deviation between the subcarriers is an appropriate value within the allowable range. It is. That is, this control is to be executed when applying the spectrum mask defined by the single carrier transmission of the point-to-point wireless device to the multicarrier transmission.

  The output level increase / decrease control for this modulation wave amplifier determines a reference subcarrier, which is a subcarrier to be used as a reference for control, and based on the signal level of the reference subcarrier, the transmission level relative to the signal level of other subcarriers Control to adjust the deviation.

  This radio transmission spectrum specification is a specification in the radio frequency band (RF band). That is, in the RF band radio signal radiated from the antenna, it is necessary to control the transmission signal level between the reference subcarrier and the other subcarriers to be within a predetermined deviation.

  The point-to-point wireless apparatus according to the present embodiment is characterized in that a radio carrier spectrum-defined multicarrier that should be satisfied in the RF band is generated in the modulation intermediate frequency band. That is, the adjustment of the signal level between the subcarriers is executed by increasing / decreasing the output level of the modulation wave amplifier of the multicarrier control unit 22.

  At this time, in the process in which the intermediate frequency band signal generated by the multicarrier control unit 22 is converted into the RF band signal by the radio transceiver 23, a level error occurs with respect to the signal output by the multicarrier control unit 22. That is, there is a radio transceiver 23 in the subsequent stage of the multicarrier control unit 22, and in the process of passing through the frequency conversion circuit and the amplifier circuit of the radio frequency band, the deviation for each radio transceiver, the deviation of the frequency band to be used, the environment An error due to a deviation or the like occurs. However, since the cause of this error is clear and determined uniquely, the point-to-point wireless apparatus of this embodiment stores this uniquely determined error in the reference value storage unit 2231 as a correction value in advance. Then, when performing increase / decrease control of the output levels of the modulated wave amplifiers 2213 and 2223 of the multicarrier control unit 22, the increase / decrease control is performed using the value converted by the correction value. Therefore, the signal levels of the subcarriers output from the modulated wave amplifiers 2213 and 2223 subjected to the increase / decrease control by the correction value conversion are the specified radio transmission spectrum in the RF band radio signal converted by the radio transceiver 23. Within the transmission level deviation.

  In other words, the point-to-point wireless apparatus according to the present embodiment corrects the transmission level deviation obtained in the RF band by adjusting the signal level in the modulation intermediate frequency band using the correction value uniquely determined as described above. It has become.

[Increase / decrease control of modulated wave amplifier output level according to parameter priority]
As described above, the increase / decrease control of the output level of the modulation wave amplifier determines the reference subcarrier, which is the subcarrier to be used as a control reference, and changes the signal level of the other subcarrier based on the signal level of the reference subcarrier. On the other hand, control for adjusting the transmission level deviation is performed.

  The wireless device ensures the opposite reception quality by operating at the maximum wireless transmission level. Therefore, normally, among the subcarriers constituting the multicarrier, the subcarrier capable of the maximum radio output is set as the reference subcarrier. Then, control is performed so that the signal levels of the other subcarriers approach the reference subcarrier.

  On the other hand, specified by “priority for securing transmission capacity (parameter 1) / priority for securing transmission quality degradation (parameter 2)”, which is a priority condition regarding the transmission environment requested by the user from the wireless device described above. It is also possible to use the subcarrier as a reference.

  The reference to the subcarrier specified by the priority condition regarding the transmission environment requested by the user from the wireless device is to set the parameter 1 or the parameter 2 to give priority to the wireless transmission.

  In the case of a condition (parameter 1) that prioritizes securing transmission capacity in a situation where interference does not occur rather than ensuring degradation of transmission quality, a high-level modulation scheme with a large number of modulation levels (for example, , 2048QAM) is set in the modulation unit of the wireless device. On the other hand, in the case of the condition (parameter 2) giving priority to securing the transmission quality degradation tolerance, a low multilevel modulation scheme (for example, 4PSK) with a small number of modulation multilevels is set in the modulation unit of the wireless device. As described above, the reference modulation method is determined by the parameter 1 / parameter 2 corresponding to the user's request and is set in the modulation unit as described above.

  In the ETSI standard, a value for securing a required C / N between adjacent channels is considered in accordance with a modulation method, and spectrum masks having different transmission levels and ranges (side masks) are defined for each modulation method. For example, the specification of 4PSK spectrum mask is loose and the maximum transmission level is specified. On the other hand, as 2048QAM becomes higher, the definition of spectrum mask becomes stricter, the transmission level becomes lower, and the side mask becomes increasingly strict due to the increase in multi-value.

  For this reason, when subcarriers under the condition of parameter 1 and subcarriers under the condition of parameter 2 are mixed, a spectrum mask corresponding to the parameter to be prioritized is applied, and output level increase / decrease control of the modulation wave amplifier is performed so as to satisfy it. There is a need to do. In other words, the setting is made to realize wireless transmission in which priority is given to either the subcarrier under the condition of parameter 1 or the subcarrier under the condition of parameter 2.

  When priority is given to securing the transmission quality degradation tolerance of parameter 2, a low-level modulation scheme is selected. In this case, since a spectrum mask having a high transmission level is applied, increase / decrease control is performed based on a subcarrier having a high signal level (referred to as case 1).

  On the other hand, when priority is given to securing the data capacity of parameter 1, a high-level modulation scheme is selected. In this case, since a spectrum mask having a low transmission level is applied, increase / decrease control is performed based on a subcarrier having a low signal level (referred to as case 2).

  Then, the signal level of the other subcarrier is increased / decreased based on the signal level of the reference subcarrier so that the radio transmission spectrum of the multicarrier satisfies the spectrum mask corresponding to the modulation scheme selected as the reference subcarrier. . This can be realized by issuing a control instruction to increase or decrease the output level of the modulation wave amplifier of the subcarrier unit to be controlled.

[Explanation of output level increase / decrease control operation of modulated wave amplifier]
The operation of increasing / decreasing the signal level for the modulated wave amplifier will be described with reference to FIGS.

  FIG. 8 is a flowchart for explaining the overall operation of signal level increase / decrease control of subcarriers for multicarrier transmission. FIG. 9 is a flowchart for explaining the operation of increasing / decreasing the output level of the modulation wave amplifier so as to satisfy the standard radio transmission spectrum specification in the operation of FIG.

  The increase / decrease control of the output level of the modulated wave amplifier is an initial setting operation that is performed before the wireless device enters operation in order to construct a wireless line that meets the priority conditions desired by the user.

  As described above, the subcarrier modulation scheme, the center frequency, and the subcarrier generated by the corresponding subcarrier unit according to the priority condition (transmission capacity priority: parameter 1 / transmission quality priority: parameter 2) regarding the transmission environment desired by the user. A bandwidth is set in advance (S201).

  For example, a modulation scheme using an optimum modulation multi-value number according to user requirements is set in the modulation section, and a center according to an interference guard frequency band for ensuring C / N required for the modulation scheme of each subcarrier. The frequency and bandwidth are set in the modulation wave frequency converter.

  Also, the reference value storage unit 2231 stores setting information related to the priority condition of which subcarrier signal level is controlled to satisfy the radio transmission spectrum specification, and setting information of an allowable range value of the transmission level to be increased or decreased. Pre-hold (S202).

  That is, the transmission level increase / decrease control in the wireless transmission spectrum specification corresponding to the priority modulation method and the information that sets whether the wireless device performs control with priority on parameter 1 or control with priority on parameter 2 Hold the tolerance value of.

  The signal level of the subcarrier output from the modulation wave amplifier of each subcarrier unit is measured by the detector of the corresponding subcarrier unit and notified to the reference value storage unit 2231 (S203).

  The reference value storage unit 2231 stores the setting information stored in advance in step S202 along with the information on the signal level of the subcarrier output from the corresponding modulated wave amplifier measured by the detector of each subcarrier unit, the level increase / decrease calculation unit 2232. Output to.

  The level increase / decrease calculation unit 2232 performs subsequent output level increase / decrease control on the modulation wave amplifier based on the setting information regarding the priority condition desired by the user, which is stored in the reference value storage unit 2231 in advance. Therefore, the level increase / decrease calculation unit 2232 determines whether the parameter of the priority condition corresponding to the user request is the parameter 1 or the parameter 2 (S204).

  When parameter 1 that prioritizes transmission capacity is set (S204, parameter 1), it is necessary to use a modulation scheme with a large number of modulation multilevels and to satisfy the radio transmission spectrum regulations corresponding thereto. Therefore, in this case, the level increase / decrease calculating unit 2232 sets a subcarrier having a low signal level as a reference subcarrier in consideration of the radio output level value of the corresponding modulation scheme (Case 2) (S205).

  Further, when parameter 2 that prioritizes transmission quality is set (S204, parameter 2), it is necessary to use a modulation scheme with a small number of modulation multi-values and to satisfy the radio transmission spectrum regulations corresponding thereto. Therefore, in this case, the level increase / decrease calculating unit 2232 sets a subcarrier having a high signal level as a reference subcarrier in consideration of the radio output level value of the corresponding modulation scheme (Case 1) (S206).

  The level increase / decrease calculating unit 2232 performs increase / decrease control of the output level of the modulation wave amplifier so that the signal level of the subcarrier output from the modulation wave amplifier satisfies the reference radio transmission spectrum specification (S207).

  That is, the level increase / decrease calculation unit 2232 calculates whether or not the signal level of the other subcarriers satisfies the allowable range to be set with reference to the signal level of the set reference subcarrier, and modulates based on the result. Increase / decrease control of output level of wave amplifier.

  For example, if the modulation scheme of the reference subcarrier is 4PSK of the low multilevel modulation scheme, the corresponding radio transmission spectrum specification also needs to conform to 4PSK, and the level increase / decrease calculation unit 2232 uses the signal level of the subcarrier on the controlled side. Control to increase.

  On the other hand, when the reference subcarrier is the high multilevel modulation method 2048QAM, the side mask according to the radio transmission spectrum is also severe. When the subcarrier on the controlled side is 4PSK modulation, the level increase / decrease calculating unit 2232 performs a decrease control to match the signal level to 2048QAM. In this case, in order to satisfy the definition of the side mask, further reduction control of the signal level of the controlled subcarrier may be required.

  As described above, the level increase / decrease calculation unit 2232 performs increase / decrease control of the output level of the modulated wave amplifier based on the setting information regarding the priority condition of the data transmission desired by the user.

  Next, the operation in step S207 in FIG. 8 will be described with reference to FIG.

  As described above, the increase / decrease control of the output level of the modulation wave amplifier is controlled so as to satisfy the radio transmission spectrum specification corresponding to the modulation scheme of the reference subcarrier. Therefore, the level increase / decrease calculation unit 2232 performs increase / decrease control on the signal level of the subcarrier that is not the reference so as to satisfy the reference radio output spectrum mask standard.

  The level increase / decrease calculating unit 2232 acquires the signal level of each subcarrier output from the modulated wave amplifier (S211). This is measured by the detector of each subcarrier unit and notified to the reference value storage unit 2231 (step S203 in FIG. 8).

  Based on the information stored in the reference value storage unit 2231 and the measured signal level of each subcarrier, the level increase / decrease calculating unit 2232 satisfies the radio transmission spectrum specification range to be set for each subcarrier. Whether or not there is is calculated (S212).

  When the prescribed allowable range is not satisfied (S212, No), the level increase / decrease calculating unit 2232 performs increase / decrease control of the output level of the target modulation wave amplifier necessary to satisfy the wireless transmission spectrum specification. The increase / decrease value is calculated (S213).

  This is because the modulation wave on the control target side is adjusted so that the difference between the signal level of the reference subcarrier and the signal level of the other subcarrier approaches the allowable value range defined in advance in the setting information of the reference value storage unit 2231. The increase / decrease value of the output level of the amplifier is calculated.

  The level increase / decrease calculating unit 2232 transmits the calculated increase / decrease value to the modulation wave amplifier on the control target side, and instructs increase / decrease control of the output level in the modulation wave amplifier (S214).

  The signal level of the subcarrier output from the modulated wave amplifier that has performed the increase / decrease control of the output level in response to this increase / decrease control instruction is measured by the corresponding detector and notified to the reference value storage unit 2231. Thereby, the process returns to step S211 again.

  The processing from step S211 to step S214 is repeated until the determination result in step S212 becomes “Yes”. That is, when it is determined that the signal level of each subcarrier satisfies the radio transmission spectrum stipulated range to be set, the signal level increase / decrease control for the modulation wave amplifier ends (S212, Yes).

  The signal level of each subcarrier, which is the final data based on the result of the increase / decrease control, is written in the nonvolatile memory of the reference value storage unit 2231.

  This is because when the wireless device is restarted for some reason, the device is restarted using the data stored in the non-volatile memory, thereby shortening the time required for rebuilding the wireless line. It is.

  In addition, when the increase / decrease control of the output level of the modulated wave amplifier is completed, the modulated wave output from each subcarrier unit is combined into a signal of a multicarrier transmission form by a combiner. After being combined with the multi-carrier transmission signal, it is converted into an IF band transmission signal by an IF band frequency converter and sent to a radio transceiver.

  The above-described increase / decrease control of the modulation wave amplifier output level is performed at the stage of initial setting of the apparatus before the start of operation. For this reason, when changing the initial setting conditions such as the priority conditions of multicarrier transmission according to the user's request after the start of operation, the control starts again by increasing / decreasing the output level of the modulation wave amplifier. When the initial setting condition is changed, the interference wave guard frequency band may change in accordance with the change of the applied modulation scheme. For this reason, as described above, by securing the band assuming the interference wave guard frequency band from 4PSK to 2048QAM, even if priority conditions are individually changed after the operation is started, there is no influence between users. You can also.

  As described above, the point-to-point radio apparatus according to the present embodiment generates and synthesizes subcarriers for multicarrier transmission in the modulation intermediate frequency band so as to satisfy the radio transmission spectrum specification for single carrier transmission. .

  For this purpose, the wireless transmission spectrum specification for single carrier transmission is stored in the reference value storage unit 2231.

  Then, in the subcarrier section that generates each subcarrier for multicarrier transmission, the center frequency and bandwidth of the subcarrier are set to the interference guard frequency band so that each subcarrier can be arranged while satisfying the radio transmission spectrum specification. Set in consideration. At this time, the modulation scheme applied to the subcarrier is considered.

  Further, the common control unit 223 increases or decreases the signal level between the generated subcarriers, and performs subcarrier amplification control so that the transmission level deviation satisfies the radio transmission spectrum specification. In this amplification control, the amplification control is executed using a correction value that takes into account a deviation when the radio transmission spectrum specification adapted in the RF band is set in the modulation intermediate frequency band.

  In addition, the point-to-point wireless apparatus according to the present embodiment also includes a configuration for constructing a wireless line according to the priority condition requested by the user.

  A user request (parameter 1) for which priority is given to transmission capacity and a user request (parameter 2) for which priority is to be given to transmission quality can be individually set for each subcarrier to be adapted to different user demands. For example, in response to a user request for giving priority to transmission capacity, a modulated wave subcarrier to which a high-level modulation method is applied is generated. Then, in response to a user request for giving priority to transmission quality, a modulated wave subcarrier to which a low-level modulation scheme is applied is generated.

  Furthermore, when subcarriers with the condition of parameter 1 and subcarriers with the condition of parameter 2 coexist, a spectrum mask corresponding to the parameter to be prioritized is applied, and increase / decrease control of the output level of the modulation wave amplifier is performed so as to satisfy it. It can be carried out.

  In order to construct subcarrier transmission set to realize wireless transmission that prioritizes the condition of parameter 1, the signal level of each subcarrier is increased or decreased so as to conform to the wireless transmission spectrum specification corresponding to the high-level modulation scheme. Control to synthesize into multi-carrier. This corresponds to Case 2 described above, and increase / decrease control is performed with reference to a subcarrier with a low signal level.

  On the other hand, in order to construct a subcarrier transmission set to realize wireless transmission in which the condition of parameter 2 is prioritized, the signal level of each subcarrier so as to conform to the wireless transmission spectrum specification corresponding to the low-level modulation scheme Increase / decrease control is performed to synthesize into multi-carrier. This corresponds to Case 1 described above, and increase / decrease control is performed with reference to a subcarrier having a high signal level.

  As a result, for users who prioritize the condition of parameter 1, it is possible to provide wireless transmission capable of ensuring the maximum element capacity in fine weather as long as data errors during raining are allowed. Conversely, for users who prioritize the condition of parameter 2, even if fading, adjacent channel interference, or the like occurs on the propagation path, it is possible to provide wireless transmission that can avoid degradation of transmission quality or disconnection of communication.

(Modification 1)
In the second embodiment, the number of subcarriers for multicarrier transmission is two. However, the present invention is not limited to this, and an arbitrary plurality of subcarriers may be generated to perform multicarrier transmission.

  In this case, the multicarrier control unit 22 shown in FIGS. 3 to 5 only needs to include subcarrier units corresponding to the number of subcarriers to be transmitted by multicarrier. Then, on the transmission side, a plurality of subcarriers generated by each subcarrier unit may be combined into a multicarrier transmission form signal by the combiner 2233 of the common control unit 223. On the receiving side, the signal in the multicarrier transmission form may be distributed to each subcarrier by the duplexer 2235 of the common control unit 223.

  The reference value storage unit 2231 of the common control unit 223 inputs the signal level of the subcarrier generated by each subcarrier unit, and the level increase / decrease calculation unit 2232 requires an increase / decrease instruction based on the result of the level increase / decrease calculation. What is necessary is just to transmit to a subcarrier part. If there are three or more subcarriers constituting a multicarrier, the level higher than the standard is adjusted to be lower with any subcarrier as a reference, and subcarriers that are originally lower than the standard are kept low. good.

  Further, in each subcarrier unit, the center frequency, bandwidth, and interference guard frequency band of each subcarrier to be arranged in the radio transmission spectrum are determined according to the number of subcarriers for multicarrier transmission and the modulation scheme. This is realized by appropriately setting the modulator and the modulation wave frequency converter.

  In particular, by adopting a device configuration in which the subcarrier unit can be added to a module in units of cards, the number of subcarriers that make up a multicarrier can be easily added without using additional devices related to the RF band even after device operation. can do.

(Modification 2)
The point-to-point wireless apparatus of this embodiment is configured to perform multicarrier transmission so as to satisfy the wireless transmission spectrum specification of single carrier transmission. For this reason, the configuration can be easily changed from a radio apparatus operated by single carrier transmission to a radio apparatus operated by multicarrier transmission.

  For example, it is assumed that a new user B increases on the same wireless line from a state where single carrier transmission is performed only by the user A. At this time, when only user A operates, single carrier transmission may be performed using one subcarrier unit and a common control unit. When the user B newly increases and multicarrier transmission including the subcarrier of user B is performed, the subcarrier part for user B may be added and multicarrier transmission may be performed as described above.

  As another example, a case is assumed in which user A and user B multiplex their respective signals at an interface unit and transmit the multiplexed signal as a single carrier. At this time, it is possible to perform multicarrier transmission by bypassing the signal multiplexing function in the interface unit and changing the configuration to a wireless device provided with a subcarrier unit and a common control unit corresponding to each user.

  When configured as in the above-described modification, it is possible to provide a point-to-point wireless device that can easily add the number of subcarriers or easily change the single subcarrier transmission form to the multicarrier transmission form. Therefore, it is possible to suppress the installation of a new wireless line, and it is possible to suppress the cost generation due to the equipment configuration.

  As described above, in this embodiment, it is possible to provide a point-to-point wireless apparatus and a communication control method that can perform multicarrier transmission while satisfying the wireless transmission spectrum specification at the time of single carrier transmission.

DESCRIPTION OF SYMBOLS 10, 20 Point-to-point radio | wireless apparatus 11 Subcarrier production | generation means 12 Level increase / decrease calculation means 13 Multicarrier synthetic | combination means 14 Wireless transmission means 21 Interface part 22 Multicarrier control part 23 Radio | wireless transmitter / receiver 221 Subcarrier part a
222 Subcarrier part b
223 Common control unit 2211, 2221 Modulation unit 2212, 2222 Modulation wave frequency conversion unit 2213, 2223 Modulation wave amplifier 2214, 2224 Detector 2231 Reference value storage unit 2232 Level increase / decrease calculation unit 2233 Synthesizer 2234, 2236 IF band frequency conversion unit 2215 , 2225 Demodulator 2216, 2226 Demodulated wave frequency converter 2217, 2227 Demodulated wave amplifier 2218, 2228 BPF
2235 duplexer

Claims (10)

Depending on the number of subcarriers for multicarrier transmission, a subcarrier converted into a modulated wave in a modulation intermediate frequency band having a center frequency and a bandwidth that can be arranged satisfying a predetermined radio transmission spectrum specification for single carrier transmission is generated. Subcarrier generation means corresponding to each subcarrier for multicarrier transmission;
The modulation signal of the modulated wave is transmitted to the subcarrier generation means so that the signal level of the subcarrier output from each of the subcarrier generation means satisfies the predetermined radio transmission spectrum specification of the predetermined single carrier transmission. Level increase / decrease calculating means for instructing increase / decrease in signal level;
When each signal level of the subcarriers satisfies the radio transmission spectrum specification, multicarrier synthesizing means for synthesizing into a multicarrier and frequency-converting to a radio intermediate frequency band, and outputting,
A point-to-point radio apparatus comprising radio transmission means for converting the multicarrier in the radio intermediate frequency band output from the multicarrier combining means into a radio frequency band transmission signal and outputting the signal. The subcarrier generation means includes
A modulation unit for setting a modulation scheme of a modulation multi-level number according to a priority condition regarding a transmission environment;
A modulation wave frequency conversion unit that converts the modulation wave output from the modulation unit into a modulation wave in a modulation intermediate frequency band having a center frequency and a bandwidth according to the number of subcarriers for multicarrier transmission;
A modulation wave amplifier for controlling the signal level of the modulation wave in the modulation intermediate frequency band output by the modulation wave frequency converter to output as a subcarrier,
A detector for measuring the signal level of the subcarrier output by the modulation wave amplifier;
A reference value storage unit that holds the radio transmission spectrum specification of the predetermined single carrier transmission in advance and inputs the signal level of the subcarrier measured by each detector of the subcarrier generation unit;
The modulation wave amplifier corresponding to the subcarrier that needs to increase or decrease the signal level is increased or decreased so that the signal level of the subcarrier input to the reference value storage unit satisfies the radio transmission spectrum specification. The point-to-point wireless device according to claim 1, further comprising a level increase / decrease calculation unit for instructing. The priority conditions regarding the transmission environment include parameter 1 that prioritizes transmission capacity and parameter 2 that prioritizes transmission quality, and the modulation unit uses a modulation scheme of a modulation multi-level number suitable for the parameter 1 or the parameter 2. And the modulation wave frequency conversion unit converts the modulation wave into a modulation wave in a modulation intermediate frequency band having a center frequency, a bandwidth, and an interference guard frequency band according to the number of subcarriers to be transmitted in multicarrier, the modulation scheme, and the like. The point-to-point wireless apparatus according to claim 2. The reference value storage unit holds in advance a setting condition that prioritizes the parameter 1 and a setting condition that prioritizes the parameter 2 as priority conditions when constructing a radio channel for multicarrier transmission. 4. The point-to-point radio apparatus according to claim 3, wherein increase / decrease in the signal level of the subcarrier is determined using the radio transmission spectrum specification prescribed in the modulation scheme corresponding to the setting condition. The reference value storage unit corrects a signal level error generated when the subcarrier output from the subcarrier generation means is converted into a signal in a radio frequency band so that the radio transmission spectrum specification is satisfied in the radio frequency band. Hold in advance as a value,
The level increase / decrease calculation means instructs the subcarrier generation means to increase / decrease the signal level of the modulated wave so as to satisfy the radio transmission spectrum specification using a value converted by the correction value. The point-to-point wireless device according to any one of claims 1 to 4. According to the number of subcarriers for multicarrier transmission, a subcarrier converted into a modulated wave of a modulated intermediate frequency band having a center frequency and a bandwidth that can be arranged satisfying a predetermined radio transmission spectrum specification of single carrier transmission is generated,
Instructing the increase / decrease of the signal level of the modulated wave so that the signal level of each of the subcarriers for multicarrier transmission satisfies the predetermined radio transmission spectrum specification of the predetermined single carrier transmission,
When the signal level of each of the subcarriers satisfies the radio transmission spectrum specification, the subcarrier is combined with a multicarrier and converted into a radio intermediate frequency band and output,
A communication control method, wherein the multi-carrier in the radio intermediate frequency band is converted into a radio frequency band transmission signal and output. 7. The communication control according to claim 6, wherein when generating each subcarrier for multicarrier transmission, a user signal is modulated using a modulation scheme with a modulation multi-level number corresponding to a priority condition related to a transmission environment. Method. The priority conditions related to the transmission environment include parameter 1 that prioritizes transmission capacity and parameter 2 that prioritizes transmission quality. When generating each subcarrier for multicarrier transmission,
A modulation multi-level modulation scheme suitable for the parameter 1 or the parameter 2 is set;
8. The communication control method according to claim 7, wherein conversion is performed to a modulated wave in a modulation intermediate frequency band having a center frequency, a bandwidth, and an interference guard frequency band according to the number of subcarriers to be transmitted in multicarrier, the modulation scheme, and the like. . As a priority condition when constructing a radio channel for multi-carrier transmission, a setting condition that prioritizes the parameter 1 and a setting condition that prioritizes the parameter 2 are stored in advance, and are defined in the modulation scheme corresponding to the setting condition. The communication control method according to claim 8, wherein increase / decrease in signal level of the subcarrier is determined using the radio transmission spectrum specification. An error of a signal level generated when the subcarrier is converted into a signal in a radio frequency band is held in advance as a correction value that satisfies the radio transmission spectrum specification in the radio frequency band,
When generating each subcarrier for multicarrier transmission, using the value converted by the correction value, the increase / decrease of the signal level of the modulated wave is instructed so as to satisfy the radio transmission spectrum specification. The communication control method according to any one of claims 6 to 9.

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