JP6679830B2 - Receiving device and receiving method - Google Patents

Description

  The present invention relates to a receiving device and a receiving method, and particularly to a receiving device and a receiving method suitable for use in communication using tropospheric scattering propagation and non-line-of-sight communication.

  A diversity reception method is used in wireless communication having a fading transmission path. In a multipath fading channel that requires a diversity scheme, interference wave cancellation and multipath distortion adaptive equalization are performed. As shown in FIG. 4, the receiving device of Patent Document 1 includes an antenna group 21, band pass filters 22a and 22b, low noise amplifiers 23a and 23b, down converters 24a and 24b, automatic gain controllers 25a and 25b, and adaptive receivers. It has matched filters 26 a and 26 b, a synthesis circuit 27, and an automatic equalization circuit 28.

  The antenna group 21 is composed of two horn antennas 21a and 21b. The receiving apparatus of FIG. 4 receives the received signals from the horn antennas 21a and 21b as two branches (reception system). The receiving apparatus of FIG. 4 receives the reception signal from the horn antenna 21a via the bandpass filter 22a, the low noise amplifier 22a, the down converter 24a, the automatic gain controller 25a, and the adaptive matched filter 26a. The receiving apparatus of FIG. 4 receives the received signal from the horn antenna 21b through the bandpass filter 22b, the low noise amplifier 22b, the down converter 24b, the automatic gain controller 25b, and the adaptive matched filter 26b.

  The combining circuit 27 performs diversity combining of the signals input from the adaptive matched filters 26a and 26b. The automatic equalization circuit 28 performs automatic equalization on the diversity-combined signal and reproduces the received signal.

International Publication No. 2013/145663

  For communication using tropospheric scattering, it is necessary to design the system considering antenna coupling loss and reception level deterioration due to long period fading. Since antenna coupling loss and long-period fading occur, a large-diameter antenna, large-power amplifier, diversity receiver, etc. are required so that communication is not interrupted even when the reception input level decreases. As a result, the system scale has become large.

  An object of the present invention is to provide a receiving apparatus and a receiving method that are suitable for communication using tropospheric scattering propagation and non-line-of-sight communication and can be downsized.

In order to achieve the above object, a receiving device according to the present invention is a receiving device that performs diversity reception by receiving signals of a plurality of antennas,
It has a plurality of above-mentioned antennas, and a control part which monitors a received signal from a plurality of above-mentioned antennas, and controls an elevation angle and a beam width of a plurality of above-mentioned antennas according to a monitoring result.

A receiving method according to the present invention is a receiving method for performing diversity reception by receiving signals from a plurality of antennas,
The received signals from the plurality of antennas are monitored, and the elevation angles and beam widths of the plurality of antennas are controlled according to the monitoring results.

  According to the present invention, the antenna coupling loss is corrected so that the communication is not interrupted even when the reception input level is lowered, so that the system scale can be reduced.

FIG. 3 is a block diagram illustrating a receiving device according to an exemplary embodiment of the inventive concept. FIG. 3 is a block diagram illustrating a receiving device according to an exemplary embodiment of the present invention. It is a schematic diagram for explaining transmission and reception by the tropospheric scattering propagation method. FIG. 6 is a block diagram of a receiving device of Patent Document 1.

  Preferred embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram illustrating a receiving apparatus according to an exemplary embodiment of the top concept of the present invention. The receiver of FIG. 1 is a dual diversity receiver provided with antennas 3a and 3b, and performs diversity reception by the received signals of the antennas 3a and 3b.

  The receiver of FIG. 1 includes antennas 3a and 3b, adaptive matched filters 9a and 9b, a combining circuit 10, a decision feedback equalizer 11, and a control unit 12. The adaptive matched filters 9a and 9b combine multipath energies. The combining circuit 10 performs diversity combining. The decision feedback equalizer 11 removes intersymbol interference.

  The control unit 12 monitors the received signals from the antennas 3a and 3b and controls the drive units 4a and 4b of the antennas 3a and 3b according to the monitoring result. By this drive, the elevation and depression angles of the antennas 3a and 3b and the beam width are controlled. For example, the control unit 12 controls the driving units 4a and 4b so as to expand the beam width of the antennas 3a and 3b when the reception input level of the reception signal from the antennas 3a and 3b is lowered. Further, the control unit 12 controls the driving units 4a and 4b so as to narrow the beam width of the antennas 3a and 3b when the reception input level of the reception signal from the antennas 3a and 3b rises.

  According to the receiving apparatus of FIG. 1, the antenna coupling loss is corrected so that the communication is not interrupted even when the reception input levels of the antennas 3a and 3b decrease, so that the system scale can be reduced. Hereinafter, preferred embodiments of the present invention will be described in more detail.

[Preferred embodiment]
A receiving device and a receiving method according to an embodiment of the present invention will be described. FIG. 2 is a block diagram illustrating a receiver according to an exemplary embodiment of the present invention. FIG. 3 is a schematic view for explaining transmission / reception by the tropospheric scatter propagation method.

(Structure of the embodiment)
The receiver of FIG. 2 is a dual diversity receiver equipped with antennas 3a and 3b, and performs diversity reception by the received signals of antennas 3a and 3b. The receiving device of the present embodiment includes a BPF (Band Pass Filter) 5a and 5b, an LNA (Low Noise Amplifier) 6a and 6b, and a D / C (Down Converter) 7a. And 7b. Further, the receiving apparatus of the present embodiment has AGC (Automatic Gain Controller) 8a and 8b, AMF (Adaptive Matched Filter) 9a and 9b, a combining circuit 10, and a DFE (Decision Feedback Equalizer). A feedback type equalizer) 11 is provided.

  Further, the receiving device of the present embodiment includes a CONT (Controller) 12 that controls the driving units 4a and 4b of the antennas 3a and 3b based on the outputs of the AGCs 8a and 8b, that is, the reception input level value after AGC.

  The BPFs 5a and 5b band-limit the signals received by the antennas 3a and 3b. LNAs 6a and 6b amplify the outputs from BPFs 5a and 5b. The D / Cs 7a and 7b frequency-convert the outputs of the LNAs 6a and 6b. The AGCs 8a and 8b control the reception input level with respect to the outputs of the D / Cs 7a and 7b. The AMFs 9a and 9b reduce unnecessary signals included in the reception signal of each branch. The combining circuit 10 performs diversity combining of the signals input from the AMFs 9a and 9b. The DFE 11 performs automatic equalization on the diversity-combined signal and reproduces the received signal while removing intersymbol interference.

  Then, the CONT 12 of the present embodiment calculates the RMS (Root mean square) of the reception input level, compares it with a threshold value, and performs drive control of the drive units 4a and 4b of the antennas 3a and 3b. For example, the RMS of the reception input level is calculated and compared with a threshold value, and drive control of the antennas 3a and 3b is performed based on the comparison result.

  For example, when the RMS of the reception input level is reduced, the beam widths of the antennas 3a and 3b are controlled to be expanded, and when the RMS of the reception input level is increased, the beam widths of the antennas 3a and 3b are narrowed. To control. When the beam width of the antenna is expanded, the antenna gain is generally lowered. Therefore, the calculation processing of the tradeoff between the coupling loss and the gain is also performed and reflected in the drive control.

  When the antennas 3a and 3b are parabolic antennas, it is possible to control the beam width by driving the horn of the antenna back and forth. Here, there is a possibility that the focal length is changed by driving the horn of the antenna, and the gain is lowered. Therefore, in the control by the CONT 12, the antenna coupling loss is corrected in consideration of the gain decrease. In the case of a parabolic antenna, the elevation and depression angle drives the parabolic antenna itself vertically.

  When the antennas 3a and 3b are phased array antennas, it is possible to control the elevation angle and the beam width.

(Operation of Embodiment)
The operation and receiving method of the receiving apparatus of this embodiment will be described more specifically. FIG. 3 shows an overview of transmission and reception using tropospheric scattering propagation. The transmitting station 100 performs non-line-of-sight communication with the receiving station 200. The transmission beam transmitted from the transmission station 100 is scattered in the troposphere. The scattering area 300 has a spatial spread called a scattering volume, and the receiving station 200 receives the beam refracted in the scattering area.

  Normally, in the line-of-sight communication, the planes of the antennas face each other, but in the case of the non-line-of-sight communication in which the scattering propagation does not directly face each other, the loss increases due to the influence of the size of the scattering region. This is called antenna coupling loss. Antenna coupling loss varies depending on the beam width and elevation angle of the transmitting and receiving antennas, and weather conditions.

The antenna coupling loss L _c is expressed by the following formula.

here,
L _ch : Horizontal coupling loss, L _cv : Vertical coupling loss θ = α + β, θ: Scattering angles θ _tm , θ _rm : Optimum elevation angles φ _th and φ _{rh of} transmitting and receiving antennas: Horizontal beam widths of transmitting and receiving antennas (α _th , α _rh ) × 0.6
φ _tv , φ _rv : Vertical plane beam width of transmitting / receiving antenna (α _tv , α _rv ) × 0.6
K1: Meteorological constant.

When the atmosphere in the troposphere convects and the refractive index of radio waves changes due to changes in temperature, humidity, and atmospheric pressure, the meteorological constant K1 and the optimum elevation angles θ _tm and θ _rm of the above equation of antenna coupling loss change. In addition, the situation of scattered propagation in the troposphere changes greatly, and long-period fading that fluctuates by 10 to 20 dB occurs throughout the year, and the reception level decreases.

  The receiving station 200 performs arithmetic processing from the received input level to adaptively control the elevation and depression angle of the antenna and the beam width. This corrects the antenna coupling loss and avoids the level drop due to long period fading.

  The received input level changes every second due to short period fading. Therefore, RMS or the like is calculated every second, and the calculated value is compared with the threshold value. When the RMS of the reception input level is lower than the threshold value, the elevation angles of the antennas 3a and 3b are UP / DOWN controlled from the driving units 4a and 4b so that the calculated value becomes higher than the threshold value. In addition, the beam width is controlled by Wide / Narrow from the drive units 4a and 4b simultaneously or in parallel so that the calculated value becomes high.

  Alternatively, the following control can be considered. That is, if the calculated value using the received input level increases, the risk of line disconnection decreases, so there is no control, or the elevation / depression angle UP / DOWN control and beam width are set to increase the calculated value. Wide / Narrow control of. If the calculated value using the received input level decreases and falls below the threshold value, the risk of line disconnection increases and the calculated value rises, so elevation / depression angle UP / DOWN control and beam width wide / narrow control are performed.

(Effects of the embodiment)
According to the receiving apparatus of the present embodiment, it is possible to avoid a decrease in the reception input level due to long period fading by correcting the antenna coupling loss.

  As a result, the size of the receiving station to which the receiving device of this embodiment is applied can be made compact, and the price can be significantly reduced. For example, assume that there is a receiving station that requires an antenna diameter of 19 m due to the circuit design. If the level reduction can be improved by 6 dB by the loss correction of the receiving device according to the present embodiment, it is possible to construct a line with an antenna of 10 m. If the antenna diameter is fixed, the amplifier can be downsized from 2kW to 0.5kW. As described above, according to the receiving device of the present embodiment, the size of the receiving station can be made compact and the price can be significantly reduced.

[Expansion of Embodiment]
Although the preferred embodiment of the present invention has been described above, the present invention is not limited to this. For example, in the receiving device of the above-described embodiment, the dual diversity receiving device has been described. However, the present invention is not limited to this, and can be applied to a quadruple, sextuple, and octave diversity receiver. It is also conceivable that the receiving station sends a control signal to the transmitting station to control the elevation angle and beam width of the antenna on the transmitting station side. The antenna is not limited to the receiving device having the horn antenna, and the receiving device having the antenna as the phased array antenna and the receiving station using the antenna can also be realized. It goes without saying that various modifications are possible within the scope of the invention described in the claims and they are also included in the scope of the invention.

The whole or part of the exemplary embodiments disclosed above can be described as, but not limited to, the following supplementary notes.
(Supplementary Note 1) A receiving device for performing diversity reception by receiving signals from a plurality of antennas,
A receiving device comprising: a plurality of antennas; and a control unit that monitors received signals from the plurality of antennas and controls elevation angles and beam widths of the plurality of antennas according to a monitoring result.
(Supplementary Note 2) The receiving device according to Supplementary note 1, wherein the control unit controls to expand the beam widths of the plurality of antennas when the reception input levels of the reception signals from the plurality of antennas decrease.
(Supplementary note 3) The reception according to supplementary note 1 or supplementary note 2, wherein the control unit controls to narrow the beam width of the plurality of antennas when the reception input level of the reception signal from the plurality of antennas rises. apparatus.
(Supplementary Note 4) The supplementary note 1 or the supplementary note 2, wherein the control unit does not control the beam widths of the plurality of antennas when the reception input levels of the reception signals from the plurality of antennas rise, and does not change the beam width. Receiver.
(Supplementary Note 5) The control unit calculates the RMS (Root mean square) of the reception input level of the reception signals from the plurality of antennas, and controls the beam width by comparing the calculation result with a threshold value. The receiving device according to any one of appendices 2 to 4.
(Supplementary note 6) The supplementary adaptive filter according to any one of supplementary note 1 to supplementary note 5, further comprising: an adaptive matched filter for synthesizing multipath energy, a synthesizing circuit for diversity synthesizing, and an equalizer for removing intersymbol interference. Receiver.
(Supplementary Note 7) A receiving method for performing diversity reception by receiving signals from a plurality of antennas,
A receiving method of monitoring a reception signal from the plurality of antennas, and controlling an elevation angle and a beam width of the plurality of antennas according to a monitoring result.
(Supplementary note 8) The reception method according to supplementary note 7, wherein when the reception input levels of the reception signals from the plurality of antennas decrease, the beam widths of the plurality of antennas are controlled to expand.
(Supplementary note 9) The reception method according to Supplementary note 7 or Supplementary note 8, wherein when the reception input levels of the reception signals from the plurality of antennas rise, the beam widths of the plurality of antennas are controlled to be narrowed.
(Supplementary note 10) The reception method according to Supplementary note 7 or Supplementary note 8, wherein when the reception input levels of the reception signals from the plurality of antennas rise, the beam widths of the plurality of antennas are not controlled and are not controlled.
(Additional remark 11) The RMS (Root mean square) of the reception input level of the reception signals from the plurality of antennas is calculated, and the beam width is controlled by comparing the calculation result with a threshold value. The receiving method according to any one of 1.

  As an application example of the present invention, it is conceivable that the present invention is applied to communication by the tropospheric scattering propagation method and non-line-of-sight communication.

3a, 3b Antenna 4a, 4b Driving unit 5a, 5b BPF (band pass filter)
6a, 6b LNA (low noise amplifier)
7a, 7b D / C (down converter)
8a, 8b AGC (Automatic gain controller)
9a, 9b AMF (adaptive matched filter)
10 Synthesis circuit 11 DFE (decision feedback equalizer)
12 CONT (control unit)
100 transmitting station 200 receiving station 300 scattering area

Claims (8)

A receiving device for performing diversity reception by receiving signals from a plurality of antennas,
A plurality of antennas, a received signal from the plurality of antennas is monitored, and a control unit that controls the elevation angle and the beam width of the plurality of antennas according to the monitoring result,
The control unit calculates RMS (Root mean square) of the reception input level of the reception signal from the plurality of antennas, and when the reception input level of the reception signal from the plurality of antennas decreases, the plurality of antennas The beam width of the antenna is controlled so as to be expanded, and the calculation processing of the trade-off between the coupling loss and the antenna gain is also performed and reflected in the control of the beam widths of the plurality of antennas.   The receiving device according to claim 1, wherein the control unit controls to narrow the beam width of the plurality of antennas when the reception input level of the reception signal from the plurality of antennas rises.   The receiving apparatus according to claim 1, wherein the control unit does not control the beam widths of the plurality of antennas and does not change the beam widths of the plurality of antennas when the reception input levels of the reception signals from the plurality of antennas rise. The receiving device according to claim 2 or 3 , wherein the control unit controls the beam width by comparing a calculation result of RMS of a reception input level of reception signals from the plurality of antennas with a threshold value. An adaptive matched filter for combining the energy of the multipath, a combining circuit for diversity combining, the reception apparatus according to any one of claims 1 to 4 and a equalizer for removing intersymbol interference, further comprising . A receiving method for performing diversity reception by receiving signals from a plurality of antennas,
The signals received from the plurality of antennas are monitored, and the elevation angle and the beam width of the plurality of antennas are controlled according to the monitoring result.
The RMS (Root mean square) of the reception input level of the reception signal from the plurality of antennas is calculated, and the beam width of the plurality of antennas is expanded when the reception input level of the reception signal from the plurality of antennas is reduced. And a calculation process of a tradeoff between the coupling loss and the antenna gain are also performed and reflected in the control of the beam widths of the plurality of antennas. The receiving method according to claim 6 , wherein when the reception input levels of the reception signals from the plurality of antennas rise, the beam widths of the plurality of antennas are controlled to be narrowed. 7. The reception method according to claim 6 , wherein when the reception input levels of the reception signals from the plurality of antennas rise, the beam widths of the plurality of antennas are not changed and the control is not performed.

Images