JP6454230B2 - Distributed antenna device - Google Patents

Description

  The present invention relates to distributed antenna technology.

  Since satellite communication has a wide service area and strong characteristics in disasters, it is widely used in offshore and digital divide areas where terrestrial links are difficult to use, and in the construction of communication environments during disasters. However, when relaying and communicating with geostationary satellites at an altitude of 36,000 km, the propagation loss is very large. When it is required to transmit a broadband / large-capacity signal such as a base station to which a plurality of users are connected or a user station that desires transmission / reception of rich content, in order to realize this, communication performance (EIRP) An earth station device with high (Equivalent Isotropic Radiated Power) and G / T (Gain to Noise Temperature Ratio) is required. As described in Non-Patent Document 1 as a technique for realizing this at a low cost, a distributed antenna device composed of a plurality of transmission / reception devices has been studied.

JP 2013-046215 A

Suzuki, Susaki, Hirose, Kobayashi, “Study on fixed-station application of distributed array antenna system,” IEICE Technical Report, SAT2011-36, Aug 2011.

  In a distributed antenna, it is necessary to compensate for fluctuations in path length and fluctuations in the RF (Radio Frequency) system. In the distributed array antenna described above, the power of the transmission signal is maximized to compensate for path length variations and RF (Radio Frequency) system variations such as BUC (Block Up Converter) and LNB (Low Noise Block Down Converter). Thus, step track control and the like are performed by looking at the satellite return signal.

  That is, FIG. 7 shows the time variation of the phase of BUC and LNB. In FIG. 7, the horizontal axis indicates time, and the vertical axis indicates the phase amount. As shown in FIG. 7, the phase of BUC and LNB varies with time, and the amount of variation varies depending on the individual difference of BUC and LNB. In the distributed array antenna, the phase with respect to each antenna is controlled so that the phases of the transmission signal and the reception signal from each antenna match. As shown in FIG. 7, since the phase amount of BUC and LNB varies with time, the phase control for each antenna needs to compensate not only the initial phase but also the phase variation component that varies with time. In the current satellite system, as shown in FIG. 8A, the transmission beam area and the reception beam area coincide. Therefore, the earth station 101 using the distributed array antenna transmits a signal from the own station to the satellite 102, detects a return signal from the satellite 102, and controls the phase so that the signal becomes maximum. Thus, phase variation can be compensated. However, in an HTS or the like that is expected to be widely used in the future, as shown in FIG. 8B, the transmission beam area and the reception beam area are different, so that it is impossible to detect the return signal.

  In view of the above circumstances, an object of the present invention is to provide a technique capable of performing high-frequency fluctuation compensation for a distributed antenna device such as a distributed array antenna without using a return signal from a satellite.

One aspect of the present invention includes a plurality of antenna apparatus, comprising a distributed antenna control device for controlling the plurality of antenna apparatus, the antenna device, IF reference signal transmitted from the distributed antenna control device and the IF reference signal Is a distributed antenna device that detects a transmission phase based on an RF reference signal obtained by up-converting the signal, and the distributed antenna control device performs phase compensation on the transmission side based on the transmission phase detected by the antenna device. .

One aspect of the present invention is the above-described distributed antenna device, wherein the frequency f _ref of the IF reference signal is expressed by the following equation (1), where f _{BUC is} the frequency of the up-conversion.
f _ref + f _BUC = Nf _ref (N: integer) (1)

One aspect of the present invention is the distributed antenna device described above, wherein the antenna device performs quadrature detection on the RF reference signal based on the IF reference signal transmitted from the distributed antenna control device. Detect the transmission phase.

One aspect of the present invention is the above-described distributed antenna device, wherein the antenna device up-converts a plurality of IF reference signals of different frequencies and a plurality of the IF reference signals transmitted from the distributed antenna control device , respectively . Based on a plurality of RF reference signals, an electrical length between the antenna device and the distributed antenna control device is obtained.

One aspect of the present invention is the above distributed antenna device, wherein the antenna device generates a phase difference signal on a transmission side based on the IF reference signal and the RF reference signal, and the distributed antenna control device Then, phase compensation on the reception side is performed based on the phase difference signal on the transmission side transmitted from the antenna device.

  According to the present invention, it is possible to perform compensation for high frequency fluctuations without using a return signal from a satellite.

It is a block diagram which shows schematic structure of the distributed antenna apparatus which can apply this invention. It is a block diagram which shows the structure of the distributed antenna control apparatus and antenna device in the 1st Embodiment of this invention. It is a block diagram of the other example of an antenna device. It is a frequency spectrum figure used for description of a reference signal. It is a flowchart of the high frequency compensation process in the 1st Embodiment of this invention. It is a flowchart of the high frequency compensation process in the 2nd Embodiment of this invention. It is a graph which shows the time fluctuation of the phase of BUC and LNB. It is explanatory drawing of a satellite system.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a distributed antenna apparatus 1 to which the present invention can be applied.

  In FIG. 1, antenna devices 11 a and 11 b constitute a distributed antenna device 1. The antenna devices 11a and 11b include BUC (Block Up Converter) 13a and 13b and LNB (Low Noise Block Down Converter) 14a and 14b. The BUCs 13a and 13b convert a transmission signal in an IF (Intermediate Frequency) band (for example, 1 GHz band) into a transmission signal in a predetermined RF (Radio Frequency) band (for example, 12 GHz band), and amplify the power. The LNB amplifies the RF band received signal and converts it into an IF band signal.

  In the distributed antenna device 1 according to the first embodiment of the present invention, the phase error detectors 15a and 15b are provided in the antenna devices 11a and 11b. The phase error detectors 15a and 15b detect the transmission initial phase and the transmission phase fluctuation based on the reference signal multiplexed and transmitted from the distributed antenna control device 20 to the transmission signal. In addition, the antenna devices 11 a and 11 b multiplex the transmission-side phase difference signal with the reception signal and send the multiplexed signal to the distributed antenna control device 20.

  The distributed antenna control device 20 controls a distributed antenna composed of the antenna devices 11a and 11b. The distributed antenna control device 20 includes a signal distributor 21 that distributes a transmission signal to each path to the antenna devices 11a and 11b, and a signal synthesizer 22 that synthesizes reception signals from each path of the antenna devices 11a and 11b. Yes.

  In addition, the distributed antenna control device 20 includes a reference signal generator 25, a transmission phase control unit 23, and a reception phase control unit 24. The reference signal generator 25 generates a reference signal for detecting an initial phase difference and phase fluctuation on the transmission side. The transmission phase control unit 23 controls the phase of the transmission signal to each of the antenna devices 11a and 11b based on the initial phase difference and the phase fluctuation obtained by the phase error detection units 15a and 15b of the antenna devices 11a and 11b. The reception phase control unit 24 receives signals from the antenna devices 11a and 11b based on the reception signals of the antenna devices 11a and 11b and the phase difference signal on the transmission side multiplexed and transmitted from the antenna devices 11a and 11b. Control the phase of the signal.

  The modem 30 is a modem for performing a satellite communication service called an HTS (High Throughput Satellite), for example. The modem 30 modulates the transmission data and sends it to the antenna devices 11a and 11b via the distributed antenna control device 20. In addition, the modem device 30 demodulates data from the received signals transmitted from the antenna devices 11a and 11b via the distributed antenna control device 20.

  In this example, the distributed antenna device 1 is configured by the two antenna devices 11a and 11b, but, of course, the distributed antenna device 1 may be configured by a larger number of antenna devices. Moreover, as an antenna unit of each antenna device 11a and 11b, any type of antenna such as a parabolic antenna or a planar antenna may be used.

  FIG. 2 is a block diagram showing the configuration of the distributed antenna control device 20 and the antenna devices 11a and 11b.

  As shown in FIG. 2, the distributed antenna control device 20 includes a reference signal generator 25, variable phase shifters 52a and 52b, adders 53a and 53b, bandpass filters 54a and 54b, and a phase difference detector 55. And variable phase shifters 56 a and 56 b and an adder 57.

The reference signal generator 25 generates a reference signal. The frequency f _{ref of the} reference signal is assumed that the frequency of the BUCs 13a and 13b is f _BUC .
f _ref + f _BUC = Nf _ref
N: Set to be an integer. The adders 53a and 53b multiplex the IF band transmission signal and the reference signal.

  The variable phase shifters 52a and 52b correspond to the transmission phase control unit 23 in FIG. The variable phase shifters 52a and 52b perform phase compensation of the transmission signals of the respective paths of the antenna devices 11a and 11b according to the phase detection signals from the antenna devices 11a and 11b.

  The bandpass filters 54a and 54b, the phase difference detection unit 55, and the variable phase shifters 56a and 56b correspond to the reception phase control unit 24 in FIG. The phase difference detection unit 55 calculates the phase difference on the reception side based on the reception signal from each antenna device 11a and 11b and the phase difference on the transmission side multiplexed and transmitted from the antenna devices 11a and 11b. To do. The variable phase shifters 56a and 56b perform phase compensation of the reception signals of the respective paths of the antenna devices 11a and 11b based on the phase difference detected by the phase difference detection unit 55.

  The antenna device 11a includes a BUC 13a, bandpass filters 62a and 63a, 1 / 2π phase shifters 64a, sample and hold circuits 65a and 66a, lowpass filters 67a and 68a, a phase detector 69a, a mixer 70a, The band pass filter 71a, the adder 72a, and the LNB 14a are included.

  The bandpass filters 62a and 63a, the 1 / 2π phase shifter 64a, the sample and hold circuits 65a and 66a, the lowpass filters 67a and 68a, and the phase detector 69a constitute the phase error detector 15a in FIG.

  The band pass filter 62a extracts the IF band reference signal from the IF band input signal. The band pass filter 63a extracts the reference signal of the RF band after passing through the BUC 13a. The 1 / 2π phase shifter 64a, the sample hold circuits 65a and 66a, and the low-pass filters 67a and 68a perform quadrature detection on the RF band reference signal using the IF band reference signal, and extract a DC component.

  The phase detector 69a calculates the transmission phase angle difference from the output signals of the low-pass filters 67a and 68a, and sends the transmission phase angle difference to the distributed antenna control device 20 as a phase detection signal.

  The mixer 70a, the band pass filter 71a, and the adder 72a multiplex information on the phase difference on the transmission side into the reception signal. The LNB 14 a down-converts the received signal in the RF band into an IF band signal and sends it to the distributed antenna control device 20.

  FIG. 3 shows another example of the antenna device 11a. In this example, mixers 165a and 166a are used instead of the sample hold circuits 65a and 66a. Other configurations are the same as those of the antenna device 11a shown in FIG.

  In FIG. 2, the antenna device 11b includes a BUC 13b, bandpass filters 62b and 63b, 1 / 2π phase shifter 64b, sample and hold circuits 65b and 66b, low pass filters 67b and 68b, a phase detector 69b, The mixer 70b, a band pass filter 71b, an adder 72b, and an LNB 14b are included. The configuration of the antenna device 11b is the same as that of the antenna device 11a. Further, a mixer may be used instead of the sample hold circuits 65b and 66b.

  Next, high-frequency fluctuation compensation in the distributed antenna device 1 according to the first embodiment of the present invention will be described. First, transmission compensation value calculation processing will be described.

A reference signal is generated from the reference signal generator 25 of the distributed antenna control device 20. This reference signal is multiplexed into a transmission signal by adders 53a and 53b as shown in FIG. As described above, the frequency f _{ref of the} reference signal is
f _ref + f _BUC = Nf _ref
It has become a relationship.

The IF band reference signal is sent from the distributed antenna control device 20 to the antenna devices 11a and 11b. In the antenna device 11a, the bandpass filter 62a extracts the reference signal S _ref1 from the multiplexed signal.

Here, the reference signal S _ref1 extracted from the bandpass filter 62a is represented as follows because a delay due to the transmission electrical length l 1 — _t from the distributed antenna control device 20 to the antenna device 11a is added.

S _ref1 = sin (2πf _ref + 2πl _{1_t} / λ _ref ) (1)
λ _ref : wavelength of reference signal

Similarly, in the antenna device 11b, the reference signal S _ref2 is extracted by the band pass filter 62b. If the transmission electrical length of the antenna device 11b is l 2 — _t , the reference signal S _ref2 extracted from the bandpass filter 62b is expressed as follows.

S _ref2 = sin (2πf _ref + 2πl _{2_t} / λ _ref ) (2)

And transmitting electrical length _{l 1_T} of the antenna device 11a, a transmission electrical length _{l 2_T} of the antenna device 11b are the same,
l _{1_t} = l _{2_t} = l
(1) and (2) are as follows.

S _ref1 = sin (2πf _ref + 2πl / λ _ref ) (3)
S _ref2 = sin (2πf _ref + 2πl / λ _ref ) (4)

In the antenna device 11a, the frequency of the IF band input signal is up-converted to the RF band by the BUC 13a. The signal from the BUC 13a is supplied to the bandpass filter 63a, and the bandpass filter 63a extracts the reference signal _{Srf1_t} upconverted to the RF band. Here, when the phase amount of the _{BUC 13a} is θ _BUC1 , the RF band reference signal S _{ref1 — t} extracted from the band pass filter 63a is expressed as follows.

S _ref1 — _t = sin {2π (f _ref + f _BUC1 ) + θ _BUC1 + 2πl / λ _ref } (5)

Similarly, in the antenna device 11b, the IF band input signal is up-converted to the RF band by the BUC 13b. The signal from the BUC 13b is supplied to the bandpass filter 63b, and the bandpass filter 63b extracts the reference signal _{Srf2_t} upconverted to the RF band. Here, assuming that the phase amount of the _{BUC 13b} is θ _BUC2 , the RF band reference signal S _{ref2 — t} extracted from the band pass filter 63b is expressed as follows.

S _ref2 — _t = sin {2π (f _ref + f _BUC2 ) + θ _BUC2 + 2πl / λ _ref } (6)

As shown in the equation (5), the signal passing through the BUC _13a includes the phase amount θ _{BUC1 of the BUC 13a} . The phase amount θ _BUC1 of the _{BUC 13a} varies with time and becomes a phase variation component on the transmission side. By orthogonally detecting the RF band reference signal shown in equation (5) with the IF band reference signal shown in equation (3) and extracting the DC component, the following signal can be obtained.

S _D1 — _sin = ½cos (θ _BUC1 −2πl (N−1) / λ _ref ) (7)
S _{D1_cos} = 1/2 sin (θ _BUC1 −2πl (N−1) / λ _ref ) (8)

From the above equation, it is possible to detect the phase value (θ _BUC1 −2πl (N−1) / λ _ref ) in the transmission path of the antenna device 11a, and when the electrical length l is known, the phase of the BUC 13a that is a phase fluctuation component The phase angle of the quantity θ _BUC1 can be directly determined.

As shown in FIG. 2, in the antenna device 11a, the 1/2 band shifter 64a and the sample-and-hold circuits 65a and 66a allow the RF band reference signal expressed by the equation (5) to be an IF band expressed by the equation (3). Quadrature detection is performed using the reference signal. The low-pass filters 67a and 68a extract the DC component from the quadrature detection output, and obtain phase values as shown in the equations (7) and (8). The phase detector 69a obtains the phase amount θ _BUC1 of the _BUC 13a from this signal with the electrical length l known.

  Similarly, when the antenna device 11b performs quadrature detection on the reference signal in the RF band expressed by the equation (6) using the reference signal in the IF band expressed by the equation (4) and extracts a DC component, the following signal is obtained. Can be obtained.

S _D2 — _sin = ½cos (θ _BUC2 −2πl (N−1) / λ _ref ) (9)
S _D2 — _cos = ½sin (θ _BUC2 −2πl (N−1) / λ _ref ) (10)

In the antenna device 11b, the RF band reference signal expressed by the equation (6) is orthogonally detected by the IF band reference signal expressed by the equation (4) by the 1 / 2π phase shifter 64b and the sample hold circuits 65b and 66b. The Then, the low-pass filters 67b and 68b extract DC components from the quadrature detection output, and signals shown in the equations (9) and (10) are obtained. The phase detector 69b obtains the phase amount θ _BUC2 of the _BUC 13b from this signal with the electrical length l known.

  As described above, in the first embodiment of the present invention, the distributed antenna control device 20 multiplexes the reference signal into the signals transmitted to the antenna devices 11a and 11b. Then, each antenna device 11a and 11b calculates the initial phase difference and the phase fluctuation on the transmission side by performing quadrature detection on the RF band reference signal using the IF band reference signal and extracting the DC component. . Then, the calculated phase value is sent from the antenna devices 11a and 11b to the distributed antenna control device 20, and the variable phase shifters 52a and 52b of the distributed antenna control device 20 change the phase of the transmission signal based on this phase value. I have control.

Next, reception compensation value calculation processing will be described. In this embodiment, the mixer 70a, the reference signal _{S ref1} of the reference signal _{S Rf1_t} and IF band in the RF band, the phase difference signal _{S Rf1_r} the transmission side is generated. This transmission-side phase difference signal S _{rf1_r} is supplied to the adder 72a via the band-pass filter 71a. The adder 72a multiplexes the reception signal in the RF band and the phase difference signal _{Srf1_r} on the transmission side.

If the input frequency band of the LNBs 14a and 14b does not match the frequency band of the phase difference signal _{Srf1_r} on the transmission side, the input frequency band is converted to the input frequency band based on the multiplied or _divided signal of the input reference signal _Sref. The phase difference signal S _{rf1 — r} on the transmission side is generated.

Similarly, the IF band reference signal _Sref2 is supplied from the bandpass filter 62b to the mixer 70b of the antenna device 11b. Further, the RF band reference signal _{Srf2_t} is supplied to the mixer 70b from the bandpass filter 63b. By the mixer 70b, the reference signal _{S ref2} of the reference signal _{S Rf2_t} and IF band in the RF band, the phase difference signal _{S Rf2_r} the transmission side is generated. The adder 72b multiplexes the reception signal in the RF band and the phase difference signal _{Srf2_r} on the transmission side.

The phase difference detection unit 55 of the distributed antenna control device 20 calculates the phase difference between the reception signals from the antenna devices 11a and 11b based on the phase on the transmission side obtained from the phase difference signals S _{rf1_r} and S _{rf2_r} on the transmission side. To do. Then, the phase difference detection unit 55 sets the phases of the variable phase shifters 56a and 56b based on the phase difference on the receiving side. Thereby, phase compensation on the receiving side is performed.

That is, the phase Φ _{t_1} on the transmission side of the antenna device 11a can be obtained from the IF band reference signal S _ref1 and the RF band reference signal S _{rf1_t} as follows.

_{Φ t_1 = θ BUC1 -2πl 1_t (} N-1) / λ ref (11)

Similarly, the phase Φ _{t_2} on the transmission side of the antenna device 11b can be obtained from the IF band reference signal S _ref2 and the RF band reference signal S _{rf2_t} as follows.

_{Φ t_2 = θ BUC2 -2πl 2_t (} N-1) / λ ref (12)

In this embodiment, the phase difference signal S _{rf1_r} on the transmission side is generated from the IF band reference signal S _ref1 and the RF band reference signal S _{rf1_t} . Further, a phase difference signal S _{rf2_r} on the transmission side is generated from the IF band reference signal S _ref2 and the RF band reference signal S _{rf2_t} . The phase difference signals S _{rf1 — r} and S _{rf2 — r} are sent to the distributed antenna control device 20. The phase Φ _{r_1} of the received signal from the antenna device 11a and the phase Φ _{r_2} of the received signal from the antenna device 11b at the input end of the distributed antenna control device 20 are shown as follows.

Φ _r — 1 =
θ _BUC1 −2πl 1 — _t (N−1) / λ _ref + θ _LNB1 −2πl 1 — _r (N−1) / λ _ref
(13)
Φ _r — 2 =
θ _BUC2 −2πl ₂ — _t (N−1) / λ _ref + θ _LNB2 −2πl ₂ — _r (N−1) / λ _ref
(14)

Here, the transmission electrical lengths of the antenna devices 11a and 11b are equal,
_l 1_t ₌ l 2_t = l _{_t}
Also, the reception electrical length is equal,
_l 1_r ₌ l 2_r = l _{_r}
Then, the phases of the received signals shown in the equations (13) and (14) are as follows.

Φ _r — 1 =
_{θ BUC1 -2πl _t (N-1} ) / λ ref + θ LNB1 -2πl _r (N-1) / λ ref
(15)
Φ _r — 2 =
_{θ BUC2 -2πl _t (N-1} ) / λ ref + θ LNB2 -2πl _r (N-1) / λ ref
(16)

In this way, the phase on the reception side of the antenna device 11a can be _obtained from the phase difference signal S _{rf1_r} on the transmission side generated from the reference signal S _ref1 on the IF side on the transmission side and the reference signal S _{rf1_t on the} RF band. it can. Similarly, the phase on the reception side of the antenna device 11b can be obtained from the phase difference signal S _{rf2_r} on the transmission side generated from the reference signal S _ref2 on the transmission side IF band and the reference signal S _{rf2_t on the} RF band. . The phase difference detection unit 55 of the distributed antenna control device 20 compares the phase of the reception side of the antenna devices 11a and 11b thus determined with the phase of the reception signal of each of the antenna devices 11a and 11b. Phase compensation is performed.

FIG. 5 shows a flowchart of the high-frequency compensation processing in the first embodiment of the present invention. In FIG. 5, the distributed antenna control device 20 generates a reference signal by the reference signal generator 25 and multiplexes it with the transmission IF signal (step S1). The phase detector 69a of the antenna device 11a calculates the initial value of the transmission phase by using the equations (7) and (8) and sends it to the distributed antenna control device 20. The distributed antenna control device 20 calculates the transmission phase value based on the initial value of the transmission phase (step S2). Then, the antenna device 11a sends the LNB14a the received signal and the phase difference signal _{S Rf1_r} the transmitting side multiplexes and outputs the distributed antenna controller 20 (step S3).

Similarly, the distributed antenna control device 20 generates a reference signal by the reference signal generator 25 and multiplexes it with the transmission IF signal (step S4). The phase detection unit 69b of the antenna device 11b calculates the initial value of the transmission phase by the equations (9) and (10) and sends it to the distributed antenna control device 20. The distributed antenna control device 20 calculates a transmission phase value based on the initial value of the transmission phase (step S5). The antenna device 11b sends the LNB14b the received signal and the phase difference signal _{S Rf2_r} the transmitting side multiplexes and outputs the distributed antenna controller 20 (step S6).

  Note that the processing from step S1 to step S3 and the processing from step S4 to step S6 are performed in parallel according to the number of antenna arrays.

Phase difference detecting unit 55 of the distributed antenna controller 20, based on the phase difference signal _{S Rf1_r} and _{S Rf2_r} the sender sent are multiplexed, the reception signal from the antenna device 11a, from the antenna device 11b The phase difference with the received signal is compared to calculate a compensation phase value. Then, the phase difference detection unit 55 sets the phase amounts of the variable phase shifters 56a and 56b based on the obtained phase difference (step S7).

  The processing from step S1 to step S3 and the processing from step S4 to step S6 are continued as processing of the time variation component. When continuing as processing of the time variation component, in step S2, the phase detection unit 69a of the antenna device 11a calculates the variation component of the transmission phase. In step S5, the phase detector 69b of the antenna device 11b calculates a transmission phase fluctuation component.

<Second Embodiment>
Next, a second embodiment of the present invention will be described. As described above, in the first embodiment of the present invention, the transmission initial phase of the path of each antenna device 11a and 11b is obtained by the equations (7) and (8) and the equations (9) and (10). Is calculated. In the expressions (7) and (8), and the expressions (9) and (10), the electrical length l is known, and the phase amounts θ _BUC1 and θ _BUC2 of the _BUCs 13a and 13b are directly calculated. However, when the electrical length l is unknown, the phase amounts θ _BUC1 and θ _BUC2 of the _{BUC 13a} and _{BUC 13b} cannot be directly calculated. In the present embodiment, even when the electrical length l is unknown, the phase amounts θ _BUC1 and θ _BUC2 can be calculated.

In this embodiment, two frequencies of frequency f _ref1 and frequency f _ref2 are used as the reference signal. That is, in the second embodiment of the present invention, the reference signal generator 25 in FIG. 2 can generate two frequencies, frequency f _ref1 and frequency f _ref2 . About another structure, it is the same as that of 1st Embodiment.

Note that the two frequencies f _ref1 and f _ref2 have the following relationship.

f _ref1 + f _BUC = Mf _ref1
f _ref2 + f _BUC = Nf _ref2
M, N: integer

If the frequency of the reference signal is f _ref1 , the phase detector 69a can obtain the following phase values.

θ _BUC1 −2πl (M−1) / λ _ref1 (17)

If the frequency of the reference signal is f _ref2 , the phase detector 69a can obtain the following phase values.

θ _BUC1 −2πl (N−1) / λ _ref2 (18)

From equation (17) and equation (18), the electrical length l and the phase amount θ _BUC1 can be obtained from simultaneous equations.

FIG. 6 is a flowchart of the second embodiment of the present invention. In FIG. 6, the distributed antenna control device 20 generates a reference signal having a frequency f _ref1 by the reference signal generator 25 and multiplexes the reference signal with a transmission IF signal (step S101). The phase detector 69a of the antenna device 11a calculates the phase value shown in the equation (17) (step S102).

The distributed antenna control device 20 generates a reference signal with the frequency f _ref2 by the reference signal generator 25 and multiplexes it with the transmission IF signal (step S103). The phase detector 69a of the antenna device 11a calculates the phase value shown in the equation (18) (step S104).

Next, the phase detector 69a of the antenna device 11a calculates the electrical length l and the phase amount θ _BUC1 from the equations (17) and (18) using simultaneous equations (step S105).

If the electrical length l can be calculated, according to the wavelength λ _data of the transmission frequency f _data of the main signal,
θ _BUC1 −2πl (N−1) / λ _data
The initial compensation value is calculated by subtracting the phase difference only (step S106).

Similarly, the distributed antenna control device 20 generates a reference signal with the frequency f _ref1 by the reference signal generator 25 and multiplexes it with the transmission IF signal (step S107). The phase detector 69b of the antenna device 11b calculates a phase value (step S108).

The distributed antenna control device 20 generates a reference signal having the frequency f _ref2 by the reference signal generator 25 and multiplexes it with the transmission IF signal (step S109). The phase detector 69b of the antenna device 11b calculates a phase value (step S110).

Next, the phase detector 69b of the antenna device 11b calculates the electrical length l and the phase amount θ _BUC2 by simultaneous equations (step S111).

If the electrical length l can be calculated, according to the wavelength λ _data of the transmission frequency f _data of the main signal,
θ _BUC2 −2πl (N−1) / λ _data
The initial compensation value is calculated by subtracting the phase difference only (step S112).

  By calculating the initial value by the above processing, the initial value is set in the variable phase shifters 52a and 52b of the distributed antenna control device 20, and transmission phase compensation can be performed (step S113).

If the initial value phase compensation can be performed, the distributed antenna control device 20 generates the reference signal by the reference signal generator 25 and multiplexes it with the transmission IF signal as in the first embodiment (step S114). Note that the frequency of the reference signal at this time may be either f _ref1 or f _ref2 .

The phase detector 69a of the antenna device 11a calculates the phase variation of the transmission phase by using the equations (7) and (8) and sends it to the distributed antenna control device 20. The distributed antenna control device 20 calculates a transmission phase value based on the phase variation of the transmission phase (step S115). Then, the antenna device 11a sends the LNB14a the received signal and the phase difference signal _{S Rf1_r} the transmitting side multiplexes and outputs the distributed antenna controller 20 (step S116).

Similarly, the distributed antenna control device 20 generates a reference signal by the reference signal generator 25 and multiplexes it with the transmission IF signal (step S117). The phase detection unit 69b of the antenna device 11b calculates the phase variation of the transmission phase according to the equations (9) and (10), and sends it to the distributed antenna control device 20. The distributed antenna control device 20 calculates a transmission phase value based on the phase variation of the transmission phase (step S118). The antenna device 11b sends the LNB14b the received signal and the phase difference signal _{S Rf2_r} the transmitting side multiplexes and outputs the distributed antenna controller 20 (step S119).

Phase difference detecting unit 55 of the distributed antenna controller 20, based on the phase difference signal _{S Rf1_r} and _{S Rf2_r} the sender sent are multiplexed, the reception signal from the antenna device 11a, from the antenna device 11b The phase difference with the received signal is compared to calculate a compensation phase value. And the phase difference detection part 55 sets the phase amount of the variable phase shifters 56a and 56b based on the calculated | required phase difference (step S120).

A program for realizing all or part of the functions of the distributed antenna device 1 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed. You may perform the process of each part. Here, the “computer system” includes an OS and hardware such as peripheral devices.
Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.
The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Distributed antenna apparatus, 11a, 11b ... Antenna apparatus, 13a, 13b ... BUC, 14a, 14b ... LNB, 15a, 15b ... Phase error detection part, 20 ... Distributed antenna control apparatus, 21 ... Signal distributor, 22 ... Signal Synthesizer, 23 ... Transmission phase control unit, 24 ... Reception phase control unit, 25 ... Reference signal generator, 30 ... Modulation / demodulation device

Claims (5)

A plurality of antenna devices;
A distributed antenna control device for controlling the plurality of antenna devices;
The antenna device detects a transmission phase based on an IF reference signal transmitted from the distributed antenna control device and an RF reference signal obtained by up-converting the IF reference signal ,
The distributed antenna control device is a distributed antenna device that performs phase compensation on a transmission side based on the transmission phase detected by the antenna device. 2. The distributed antenna device according to claim 1, wherein the frequency f _ref of the IF reference signal is represented by the following expression (1), where f _BUC is the up-conversion frequency.
f _ref + f _BUC = Nf _ref (N: integer) (1) The distributed antenna according to claim 1, wherein the antenna device detects the transmission phase by performing quadrature detection on the RF reference signal based on the IF reference signal transmitted from the distributed antenna control device. apparatus. The antenna device and the antenna device and the dispersion based on a plurality of IF reference signals having different frequencies transmitted from the distributed antenna control device and a plurality of RF reference signals obtained by up-converting the plurality of IF reference signals, respectively. The distributed antenna device according to claim 1, wherein an electrical length between the antenna control device and the antenna control device is obtained. The antenna device generates a phase difference signal on the transmission side based on the IF reference signal and the RF reference signal,
The distributed antenna control device performs phase compensation on the reception side based on the phase difference signal on the transmission side transmitted from the antenna device ;
The distributed antenna apparatus as described in any one of Claim 1 to 4 .

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