JP2001223628A - Relay system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio repeating installation that can sufficiently ensure attenuation between a transmitter and a receiver with respect to a sneaked path wave, fully reducing the effect of the sneaked path wave. SOLUTION: An adaptive array antenna is adopted for a reception antenna 13 or a transmission antenna 24. Then in a training operation mode, a sneaked path direction of a sneaked path arrival direction is detected, on the basis of a reference signal generated by a reference signal generating section 30. In normal operation mode, the directivity of the reception antenna 13 or the transmission antenna 24 is adjusted, to decrease the directivity in the sneaked path direction or the sneaked path wave arrival direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio repeater, and more particularly to a technique for reducing the influence of a loop wave from a transmitting antenna to a receiving antenna.

[0002]

2. Description of the Related Art As a method of expanding a service area of a terrestrial television or the like, there is a broadcast wave relay system for receiving a broadcast wave, amplifying the power thereof, and retransmitting the amplified broadcast wave. In a conventional analog television broadcast, a broadcast wave is received by a reception antenna of a wireless relay device (relay station), power is amplified, and then the broadcast wave is retransmitted from a transmission antenna at a frequency different from the reception broadcast wave. However, digital television broadcasting, which is currently under development, is based on OFDM (Orthogonal
Since the frequency division multiplexing (orthogonal frequency division multiplexing) system is adopted, a so-called SFN (reception of a broadcast wave at the same frequency as a received broadcast wave) is performed after a broadcast wave is received by a wireless relay device, and power is amplified. Single Frequ
ency Network (single frequency network). According to the SFN, the frequency can be effectively used.

[0003]

SUMMARY OF THE INVENTION However, SFN
In order to realize the above, the effect of a so-called loop wave, in which a transmission wave from a transmission antenna wraps around a reception antenna of the same wireless relay apparatus, cannot be ignored. That is, in the SFN, since the same frequency is used for the transmission wave and the reception wave, spatial feedback occurs due to the loop phenomenon, and when the feedback ratio is large, even the oscillation state occurs. In this case, the relay signal is deteriorated.

When the delay time and the power are the same between the loop wave and the multipath, the characteristic deterioration due to the loop phenomenon is greater than that due to the multipath. For this reason, it is necessary to secure a large amount of attenuation between transmission and reception with respect to the amplification gain of the wireless relay device, and to avoid characteristic deterioration due to the loop phenomenon. As a countermeasure, the use of one or two Yagi-Uda antennas or parabolic antennas with sharp horizontal directivity for the receiving and transmitting antennas has been studied, but this method prevents oscillation caused by the wraparound phenomenon. In this case, the transmission and reception attenuation cannot be sufficiently secured.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a radio relay apparatus capable of sufficiently securing an attenuation between transmission and reception with respect to a loop wave and reducing the influence thereof. It is in.

[0006]

Means for Solving the Problems (1) In order to solve the above problems, a radio relay apparatus according to the present invention is configured to include a transmitting antenna and a receiving antenna, and to transmit a signal received by the receiving antenna. In a wireless relay device that amplifies and retransmits from the transmission antenna, the reception antenna is configured to be capable of adjusting reception directivity, and a wraparound wave arrival detecting wraparound wave arrival direction information from the transmission antenna to the reception antenna. A directional control unit configured to adjust a reception directivity of the receiving antenna based on the arrival direction information so as to reduce a reception sensitivity to the wraparound wave.

In the present invention, the receiving antenna is configured to be able to adjust the receiving directivity by using, for example, an adaptive array antenna. Then, the reception directivity of the receiving antenna is adjusted based on the arrival direction information of the wraparound wave so that the reception sensitivity to the wraparound wave is reduced. In this way, it is possible to secure a sufficient amount of attenuation between the transmission and the reception of the loop interference wave and reduce the influence thereof.

In one aspect of the present invention, the wraparound wave arrival direction detecting means includes a reference signal generating means for generating a predetermined reference signal, and a spread signal obtained by spectrum spreading the reference signal with a predetermined spreading code. A spread signal transmitting means for transmitting from a transmitting antenna, and a reference signal extracting means for extracting the reference signal by despreading the spread signal received by the receiving antenna with the spreading code; Detecting arrival direction information of the wraparound wave based on a reference signal extracted by the means.

According to this aspect, the spread signal transmitted from the transmitting antenna goes around to the receiving antenna. Then, the original reference signal is extracted by despreading the spread signal wrapped around the receiving antenna, and the arrival direction information of the wraparound wave is detected based on the original reference signal. In this way, it is possible to accurately detect the arrival direction information of the wraparound wave while avoiding interference.

Further, in one aspect of the present invention, the interference signal arrival direction detecting means reduces a difference between a reference signal generated by the reference signal generating means and a reference signal extracted by the reference signal extracting means. Tentatively adjusting the reception directivity of the receiving antenna and generating a result of the tentative adjustment as arrival direction information of the wraparound wave, the directional adjustment means comprising: Based on the result of the provisional adjustment, which is information, includes directivity readjustment means for readjusting the reception directivity of the receiving antenna such that the signal level of the reference signal extracted by the reference signal extraction means is reduced. I do.

According to this aspect, first, the reception directivity is provisionally adjusted so that the difference between the reference signal generated by the reference signal generation means and the reference signal extracted by the reference signal extraction means is reduced. . In this way, the reception directivity is provisionally adjusted so that the wraparound wave can be received without interference. Then, the result of the provisional adjustment (weight information or the like in the adaptive array antenna) becomes the arrival direction information of the wraparound wave. Thereafter, based on the direction-of-arrival information, the reception directivity of the receiving antenna is readjusted such that the signal level of the reference signal extracted by the reference signal extraction means is reduced. That is, the reception directivity is readjusted based on the arrival direction information of the wraparound wave so as to reduce the reception sensitivity to the wraparound wave. In this way, by performing the inverse characteristic on the temporary adjustment result, it is possible to reduce the reception sensitivity to the loop interference wave. As a result, it is possible to reduce the influence of the loop wave in the wireless relay device.

Further, in one aspect of the present invention, the wraparound wave arrival direction detecting means includes a signal transmitting means for transmitting a predetermined signal from the transmitting antenna, and a receiving directivity of the receiving antenna so as to have a null point in a predetermined direction. Null point generation means for adjusting the predetermined direction, sequentially changing the predetermined direction, examining the predetermined direction in which the signal level of the predetermined signal received by the receiving antenna is minimal, and including the information for specifying the direction. Wraparound direction sweep detection means for generating arriving direction information of a wave, wherein the directivity adjustment means includes a reception directivity of the receiving antenna so as to have a null point in a direction specified by the direction of arrival information of the wraparound wave. It is characterized by adjusting the sex.

In this aspect, first, the receiving directivity of the receiving antenna is adjusted so that the direction of the null point is sequentially changed, and as a result, the null point at which the signal level of the predetermined signal wrapping around from the transmitting antenna to the receiving antenna is minimized. Is checked. Then, the receiving directivity of the receiving antenna is adjusted so as to have a null point in this direction, and the receiving sensitivity to the sneak wave is reduced. In this way, the influence of the loop wave in the wireless relay device can be reduced.

(2) Further, a radio relay device according to the present invention is configured to include a transmitting antenna and a receiving antenna,
In a wireless relay device that amplifies a signal received by the receiving antenna and retransmits the signal from the transmitting antenna, the transmitting antenna is configured to be capable of adjusting radiation directivity, and extends in a direction from the transmitting antenna to the receiving antenna. A wraparound direction detecting means for detecting the corresponding wraparound direction information, and a directivity adjustment means for adjusting the radiation directivity of the transmitting antenna so as to reduce the radiation intensity of the radio wave in the wraparound direction based on the wraparound direction information, It is characterized by including.

In the present invention, the transmission antenna is configured to be capable of adjusting the radiation directivity by using, for example, an adaptive array antenna. Then, based on the wraparound direction information, the radiation directivity of the transmitting antenna is adjusted so that the radiation intensity in the wraparound direction is reduced. In this way, it is possible to secure a sufficient amount of attenuation between the transmission and the reception of the loop interference wave and reduce the influence thereof.

In one aspect of the present invention, the wraparound direction detecting means includes: a reference signal generating means for generating a predetermined reference signal; and a transmitting antenna for transmitting a spread signal obtained by spectrum spreading the reference signal with a predetermined spreading code. And a reference signal extracting means for extracting the reference signal by despreading the spread signal received by the receiving antenna with the spreading code, wherein the reference signal extracting means The wraparound direction information is detected based on the extracted reference signal.

According to this aspect, the spread signal transmitted from the transmitting antenna goes around to the receiving antenna. Then, the original reference signal is extracted by despreading the spread signal wrapped around the receiving antenna, and wraparound direction information is detected based on the reference signal. This makes it possible to accurately detect the wraparound direction information while avoiding interference.

In one aspect of the present invention, the wraparound direction detecting means is configured to reduce a difference between a reference signal generated by the reference signal generating means and a reference signal extracted by the reference signal extracting means. Provisionally adjusting the radiation directivity of the transmitting antenna, including a directivity temporary adjustment means for generating a result of the temporary adjustment as the wraparound direction information, wherein the directivity adjustment means adjusts the result of the tentative adjustment as the wraparound direction information. A directivity readjustment unit for readjusting the radiation directivity of the transmission antenna such that the signal level of the reference signal extracted by the reference signal extraction unit is reduced.

According to this aspect, first, the radiation directivity is provisionally adjusted so that the difference between the reference signal generated by the reference signal generation means and the reference signal extracted by the reference signal extraction means is reduced. . In this case, the radiation directivity of the transmitting antenna is temporarily adjusted so that the looping wave can be received without interference. Then, the result of the temporary adjustment (weight information and the like in the adaptive array antenna) becomes the wraparound direction information. Thereafter, based on the wraparound direction information, the radiation directivity of the transmitting antenna is readjusted such that the signal level of the reference signal extracted by the reference signal extracting means is reduced. That is, the radiation directivity of the transmitting antenna is readjusted based on the wraparound direction information so as to reduce the radiation intensity in the wraparound direction. In this way, by performing the inverse characteristic on the temporary adjustment result, the radiation intensity in the wraparound direction can be reduced. As a result, it is possible to reduce the influence of the loop wave in the wireless relay device.

Further, in one aspect of the present invention, the wraparound direction detecting means adjusts the radiation directivity of the transmitting antenna so as to have a null point in a predetermined direction, with the signal transmitting means transmitting a predetermined signal from the transmitting antenna. Null point generating means for sequentially changing the predetermined direction, examining the predetermined direction in which the signal level of the predetermined signal received by the receiving antenna is minimized, and the wraparound direction information including information for specifying the direction. Wraparound direction sweep detection means for generating the directional direction, wherein the directivity adjustment means adjusts the radiation directivity of the transmission antenna so as to have a null point in a direction specified by the wraparound direction information. .

In the present embodiment, first, the radiation directivity of the transmitting antenna is adjusted so that the direction of the null point is sequentially changed, and as a result, the null point at which the signal level of the predetermined signal from the transmitting antenna to the receiving antenna is minimized. Is checked. Then, the radiation directivity of the transmitting antenna is adjusted so as to have a null point in this direction, and the radiation intensity in the wraparound direction is reduced. In this way, the influence of the loop wave in the wireless relay device can be reduced.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

Embodiment 1 FIG. 1 is a diagram showing a configuration of a wireless relay device according to Embodiment 1 of the present invention.

As shown in FIG.
Is configured to include a switch 18 and a switch 20. The receiving antenna 13 is configured using an adaptive array antenna, and when both the switch 18 and the switch 20 are set to the S1 side, the training for the receiving antenna 13 is performed. Hereinafter, this operation mode is referred to as a training operation mode. In addition, as an adaptive array antenna, TDL (Tapped Del
ay Line: a delay line with a tap) An adaptive array antenna or a band division type adaptive array antenna can be used. As the array of the adaptive array antennas, a linear array antenna or a planar array antenna can be used.

On the other hand, an operation mode in which both the switch 18 and the switch 20 are set to the S2 side is referred to as a normal operation mode. In this normal operating mode,
Normal adaptive equivalent processing by the weight control unit 46 is performed on the reception antenna 13. That is, the receiving antenna 13 includes the antenna elements 12-1 to 12-K,
Complex reception signal x received by antenna element 12-i
_i is supplied to the weight control unit 46 and also to the multiplier 14-i (i = 1 to K; K is the number of antenna elements). The multiplier 14-i is supplied with the complex weight w _i from weight control section 46, both the complex multiplication is performed here. The output of the multiplier 14-i is
Is supplied to

In the training operation mode, the adder 16
, I.e., the array output y is supplied to the multiplier 38 via the switch 18. The spreading sequence is supplied to the multiplier 38 from the synchronization acquisition holding unit 28. The synchronization acquisition holding unit 28 can be configured using, for example, a sliding correlator and a delay locked loop (DLL). A spread sequence having a phase synchronized with the array output y is output from the synchronization acquisition holding unit 28. The phase information obtained by the synchronization acquisition holding unit 28 is also supplied to the delay circuit 32. The spreading sequence used in the synchronization acquisition holding unit 28 is generated by the spreading sequence generator 26. The multiplier 38 multiplies the spread sequence supplied from the synchronization acquisition holding unit 28 by the array output y, thereby performing despreading processing using the spread sequence generated by the spread sequence generator 26. The despread signal is supplied to the adder 34 with a negative sign. The adder 34 is also supplied with a reference signal from the reference signal generator 30 via the delay circuit 32. That is, the reference signal generation unit 30 generates, for example, a signal obtained by temporarily modulating random data as a reference signal.
Is supplied to the adder 34 via the. In addition, as a modulation method in the reference signal generation unit 30, for example, BPSK
Can be used.

The reference signal generated by the reference signal generator 30 is also supplied to a multiplier 48. The multiplier 48 is also supplied with a spread sequence generated by the spread sequence generator 26, where the spectrum of the reference signal is spread. The spread signal output from the multiplier 48 is supplied to the amplifier 22. The amplifier 22 amplifies the spread signal and transmits it from the transmitting antenna 24. Thus, the signal extracted from the array output y by the despreading process in the multiplier 38 is
This corresponds to the reference signal generated by the reference signal generator 30. That is, the output of the multiplier 38 corresponds to a loop wave from the transmitting antenna 24 to the receiving antenna 13.

From the adder 34, the reference signal generator 30
Reference signal supplied through delay circuit 32 and multiplier 38
Is output as the difference from the despread signal supplied from. This mistake
The difference signal is supplied to the weight control unit 46. Weight system
In the control unit 46, for example, MMSE (Minimum Mean Square)
Error) weight calculation processing using the criterion is performed. Ingredient
Specifically, LMS (Least Mean Square) method, RLS (R
ecursive Least Square) method or SMI (Sample Matr)
ix Inversion) complex weight W _i(I =
1 to K) are calculated. In this way, the training operation
In the mode, the reception directivity of the reception antenna 13 is adjusted.
Tuned, high reference signal without interference
You will be able to receive at the level. In this state
Is the complex weight W_iInformation related to the direction of arrival of wraparound waves
Information will be stored. In the first embodiment,
Is the complex weight W_iThe arrival of the wraparound wave
Used as direction information.

After that, from the training operation mode,
When the operation mode can be switched, the switch 18 and the switch
The switches 20 are both set to the S2 side. At this time,
From the site control unit 46, the latest
Complex weight W_iIs supplied to the inverse characterization unit 44. Reverse
In the sexualizing section 44, the complex supplied from the weight control section 46
Weight W_iIs used to perform the inverse characterization process. That is,
Complex weight W supplied from weight control unit 46_iIs
You can receive the wraparound wave at a strong signal level
This is set by the inverse characterization process.
Complex weight W _iLow receiving sensitivity to wraparound waves
Convert so that And the complex
Weight W_iIs returned to the weight control unit 46. Weight system
In the control unit 46, the complex way supplied from the inverse characterization unit 44
W_iIs supplied to the multiplier 14-i (i = 1 to K), and is received.
The reception directivity of the antenna 13 is adjusted.

The array output y output from the adder 16 in the normal operation mode is supplied to the pilot signal extraction section 40 via the switch 18. The pilot signal extracting section 40 extracts various pilot signals from the array output y. For example, if the received signal is modulated by the OFDM method, an SP (Scattered Pilot) signal or a CP (Continual Pilot) signal is extracted. In addition, TMCC (Transmission and Multiplexing Conf.
reference bit for differential demodulation and synchronization signal, or AC (Auxiliary Channel)
Like a reference bit of a signal, a control signal whose pattern is promised between transmission and reception may be extracted.

The pilot signal extracted by the pilot signal extracting section 40 is given a negative sign and supplied to the adder 36. The adder 36 has a pilot signal generator 4
2 also supplies a pilot signal. The pilot signal generating section 42 generates a signal corresponding to the pilot signal extracted by the pilot signal extracting section 40. For example, when the received signal is modulated by the OFDM method, the SP signal or the CP signal is generated. Generate The SP signal and the CP signal are subjected to a predetermined modulation method (BPSK modulation), and are output in a predetermined carrier arrangement. Similarly to the pilot signal extraction unit 40, the pilot signal generation unit 42 has a pattern between transmission and reception although it is a control signal, such as a reference bit for differential demodulation and a synchronization signal in a TMCC signal or a reference bit of an AC signal. May be generated as promised. In this case, some components of the TMCC signal, the AC signal, and the like may be generated, and a signal obtained by performing a predetermined modulation scheme (DBPSK) on the signal may be output in a predetermined carrier arrangement.

In the adder 36, a pilot signal extracting unit 40
And pilot signal generator 4 extracted by
The difference from the pilot signal generated in step 2 is generated and supplied to the weight control unit 46 as an error signal.
The weight control unit 46 performs adaptive equivalent processing using the MMSE criterion as in the case of the training operation mode.
Complex weight W _i generated by the weight controller 46,
The signal is supplied to a multiplier 14-i provided in the receiving antenna 13 (i = 1 to K).

In the above description, the wireless relay device 10
Each of the blocks performs the signal processing at the intermediate frequency (IF), but may perform the signal processing at the baseband (BB). In this case, the reference signal generator 30 and the pilot signal generator 42 generate unmodulated signals.

Next, the inverse characterization process by the inverse characterization unit 44 will be described in detail.

Firstly, the complex weight vector W for the complex weight _{W i} for antenna element 12-i as elements
(T) is defined as in the following equation (1).

[0036]

(Equation 1) Also, if defined as following equation (2) complex input vector X (t) is the received complex signal x _i received by the antenna element 12-i and element array output is the output of the adder 16 y ( t) can be expressed as in the following equation (3). Here, T represents transpose, * represents complex conjugate, and H
Represents a complex conjugate transpose.

[0037]

(Equation 2) When digital control is performed at the sampling interval Ts, t = mTs can be expressed (m = 1,
2,3 ...). At this time, the complex input vector X (t),
Complex weight vector W (t) and array output y (t)
Are represented as X (m), W (m) and y (m), respectively.

In the weight control section 46, as described above, M
The adaptive equivalent processing using the MSE criterion is performed, but when shifting from the training operation mode to the normal operation mode, the latest complex weight vector W (t) at that time is used as the optimum weight W _opt (direction-of-arrival-wave arrival direction information). Output. The optimum weight W _opt is represented by the following equation (4), and is supplied to the inverse characterization unit 44.

[0039]

(Equation 3) In the inverse characterization unit 44, based on the optimum weight W _opt , the inverse directional characteristic weight W _inv expressed by the following equation (5)
Is calculated and supplied to the weight control unit 46.

[0040]

(Equation 4) Specifically, the inverse characterization unit 44 uses the optimum weight W _opt supplied from the weight control unit 46 to obtain the following equation (6).
The function shape of the power directivity function D _p (φ) shown in FIG.

[0041]

(Equation 5) In the equation (6), V (φ) is a direction vector of the receiving antenna 13 and is represented by the following equations (7) and (8) (here, a linear adaptive array antenna is assumed as the receiving antenna 13).

[0042]

(Equation 6) Next, in the inverse characterization unit 44, the angles φ _min1 , φ _min2 ,..., Φ corresponding to the minimum value of the power directivity function D _p (φ)
_minL and the power directivity function D
Angles φ _max1 and φ corresponding to the maximum value of _p (φ)
_max2, ..., to calculate the φ _maxL. Here, L represents the number of angles to be calculated, and is an integer satisfying the following equation (9).

[0043]

(Equation 7) Also, angles φ _min1 , φ _min2 ,..., Φ _minL ,
And _{φ max1, φ m ax2, ...} , φ maxL is calculated to satisfy the following equation (10) (11).

[0044]

(Equation 8) Next, the inverse characterization unit 44 calculates an array response value D (φ for each local maximum value and local minimum value according to the following equation (12).

[0045]

(Equation 9) Moreover, to calculate the complex conjugate against reverse directional characteristic weight _{W in v} according the inverse characterization unit 44 following equation (13).

[0046]

(Equation 10) For example, when the number L of angles to be calculated is L = K-1, the complex conjugate with respect to the inverse directivity characteristic weight _Winv is calculated by the following equation (14).

[0047]

[Equation 11] When the complex conjugate of the inverse directivity characteristic weight _Winv is calculated in this way, the inverse characterization unit 44 calculates the complex conjugate,
The inverse directivity characteristic weight _Winv is derived.

The inverse characterization unit 44 calculates the inverse directional characteristic weight W corresponding to the optimum weight W _opt as described above.
Calculate _inv . The weight control unit 46 performs weight control in the normal operation mode based on the backward directivity characteristic weight _Winv . At this time, the reverse directivity characteristic weight W
_Inv may be used as an initial value of the weight control, or in the normal operation mode, the backward directivity characteristic weight _Winv may be used fixedly or semi-fixedly.

In the above processing, the angle φ that gives the maximum value and the minimum value of the power directivity function D _p (φ) with respect to the optimum weight W _opt is calculated, and the angle φ that gives the maximum value and the angle φ that gives the minimum value are calculated. _Are calculated such that the inverse directional characteristic weight _Winv is replaced. By doing so, it is possible to lower the receiving sensitivity in the direction of arrival of the reference signal which is a wraparound wave. Thus, according to radio relay apparatus 10 of the first embodiment, it is possible to reduce the influence of the loop interference and prevent deterioration of the relay signal.

Embodiment 2 FIG. 2 is a diagram showing a configuration of a wireless relay device according to Embodiment 2 of the present invention.

Wireless relay apparatus 10a shown in FIG. 10 is different from wireless relay apparatus 10 according to the first embodiment in that the reference signal obtained by the despreading process in multiplier 38 is supplied to weight control section 46a. Is different. In the wireless relay device 10a, the reference signal generated by the reference signal generation unit 30 is not supplied to the weight control unit 46a. In the figure, the same components as those of the wireless relay device 10 shown in FIG. 1 are denoted by the same reference numerals, and the detailed description is omitted here.

The weight controller 46a includes a switch 18
In the training operation mode in which the switch 20 and the switch 20 are both set to the S1 side, the reference signal output from the multiplier 38 is supplied. And the receiving antenna 1
A null point (point having no directivity) of 3 is swept, and the angle of the null point and the level of the loop wave at that angle are maintained. Then, the minimum value of the level of the loop wave is calculated, and the angle of the null point corresponding to each minimum value is calculated. Then, considered DOA angle sneak wave null point corresponding to the minimum value, calculates a complex weight W _i having a null point in that direction. That is, in the second embodiment, the direction of the null point at which the level of the wraparound wave is minimized is used as so-called arrival direction information of the wraparound wave.

[0053] Switches 18 and the set switch 20 to S2 side shifts to the normal operation mode, the multiplier complex weights W _i calculated in the training mode of operation 14-
the initial value of the complex weight W _i supplied to i, the adder 3
The adaptive equalization process is performed based on the error of the pilot signal supplied from 6. Thus, thereafter, the complex weights Wi supplied to the multipliers 14- _i are sequentially updated.

[0054] More specifically, in the training mode of operation, the wait control unit 46a is as follows to calculate the complex weight W _i.

First, the arrival direction of the broadcast wave (in the case of a fixed station,
Known) desired wave direction φ_D(-90 ゜ <φ_D<90 ゜) and
And the null angle φ_null(-90 ゜ <φ
_null<90 °), and using these, the following equation (15)
The complex weight W shown in₁, W ₂Is calculated.

[0056]

(Equation 12) When adjusting the directivity of the receiving antenna 13 so as to have one null point, the two antenna elements 12-1 and 12-2
Weight control is sufficient. Here, it is assumed that the receiving antenna 13 is a linear adaptive array antenna, and that the antenna elements 12-1 to 12-K are arranged at regular intervals on a straight line in this order. Here, based on such circumstances, the null point is swept using only the antenna elements 12-1 and 12-2. Specifically, sequentially assigns the value of the predetermined distance +90 DEG from -90 ° as null angle phi _null against the above equation (15), a complex weight _W 1, _{W 2} corresponding to the null angle phi _null calculate. And
The directivity of the receiving antenna 13 is adjusted using the complex weights W ₁ and W ₂ calculated for each null angle φ _null , and reception of a reference signal wrapping around the adjusted receiving antenna 13 from the transmitting antenna 24. The level is stored together with the null angle φ. Then, it is determined that the null angle φ when the reception level of the reference signal becomes a minimum is the arrival direction of the wraparound wave.

If the directions of arrival of the wraparound waves thus obtained are represented as φ _null1 , φ _null2 ,..., Φ _null L (where L <K), the antenna elements 12-1 to 12-1
Complex weight _W 1 to _W-K for 2-K is obtained as follows. That is, the antenna elements 12-1 to 12-
The complex weights W _{1 to} W _{L + 1} for _{L + 1} are given by the following equation (1)
6).

[0058]

(Equation 13) The equation (16), which has a null point in the arrival direction of the loop interference, intended to calculate, as has sufficient directivity with respect to a desired wave direction phi _D, the complex weight W ₁ ~W L + ₁ It is. Complex weights W _{L + 2 to} W _{L + 3} ,
..., _{W K} are all 0 (L <In the case of K-1).

The vector having the complex weight W _i obtained as a component is supplied to the multiplier 14-i, and the switch 1
8 and the switch 20 is the normal operation mode set in both side S2 includes an adder 36 to start a wait control based on the error signal supplied from these complex weights W _i as an initial value (i = 1 to K) . In this control, as in the case of the first embodiment, the complex weight _Wi is calculated using the MMSE criterion, for example, by the LMS method, the RLS method, or the SMI method.

According to the above-described radio relay apparatus 10a, it is possible to detect the direction of arrival of the wraparound wave by sweeping the null point. In other words, if the receiving antenna 13 whose reception directivity is adjusted so as to have a null point in a certain direction has low reception sensitivity to the wraparound wave, the direction is determined to be the arrival direction of the wraparound wave. Then, the complex weight W _i is calculated so as to have a null point in that direction, and the weight control in the normal operation mode is started using the calculated weight W _i . Thus,
It is possible to suppress the wraparound from the transmitting antenna 24 to the receiving antenna 13.

The wireless device 10a can be variously modified.

For example, in the above description, the training operation
Null point in the direction of arrival of the wraparound wave calculated in the operation mode
Complex weight W_iThe way in normal operating mode
Used as the control initial value in the normal operation mode.
Complex weight W _iIn calculating
It is said that the arrival direction of the nested wave matches the direction of the null point
The condition may be maintained and calculated.
No. That is, the complex weight W in the normal operation mode
_iWas calculated in the training operation mode.
It is said that the direction of arrival of the wraparound wave matches the direction of the null point.
This condition may be used as the constraint condition. This way, normal operation
After entering the mode, the
Since the reception sensitivity is continuously suppressed, the influence of the loop interference
Can be effectively reduced.

In the above description, the case where a linear adaptive array antenna is used as the receiving antenna 13 has been described. However, a configuration using a planar adaptive array antenna may be used. In this case, the above procedure may be performed in two directions, the horizontal direction and the vertical direction. That is, first, a null point is swept in the horizontal direction based on the following equation (17), and the following equation (1) is obtained.
Null points are swept in the vertical direction based on 8), and the reception level of the sneak wave is held in the direction of each null point.

[0064]

[Equation 14] Here, the angle in the horizontal direction (m direction) is φ, the angle in the vertical direction (n direction) is ψ, the desired wave direction is (φ _D , ψ _D ),
Let the null angle be (φ _null , ψ _null ) (−90
゜ <φ _D <90 ゜, −90 ゜ <ψ _D <90 ゜, -90 ゜ <φ _null <90 ゜, -90 ゜ <ψ _null <90
゜). The element number of the antenna element 12 is K = m + M
(M = 1,..., M; n = 1,
.., N; k = 1,..., K (= MN)).

[0065] Thereafter, null angle (φ _null, ψ _{nu ll)} the reception level of self interference is minimized by selecting one or more, the arrival direction of the direction loop interference. Then, the reception directivity of the reception antenna 13 is adjusted so that the arrival direction of the loop interference wave is set to a null point. This way,
By taking into account both the horizontal direction and the vertical direction, it is possible to prevent wraparound.

Embodiment 3 FIG. 3 is a diagram showing a configuration of a wireless relay device according to Embodiment 3 of the present invention.

Radio relay apparatus 10b shown in FIG. 10 differs from radio relay apparatus 10a according to the second embodiment in that pilot signal extracting section 40, pilot signal generating section 42 and adder 3
6 is not particularly provided. Correspondingly, only the output of the multiplier 38 is supplied to the weight control section 46. For other configurations, refer to the wireless relay device 10a.
Here, the same reference numerals are given and the description is omitted.

In the radio relay apparatus 10b, when the switch 18 and the switch 20 are both set to the S1 side and in the training operation mode, the weight control unit 46a provided in the radio relay apparatus 10a according to the second embodiment operates in the same manner. Then, the weight control unit 46b performs a weight calculation process. That is, the complex weight _Wi is calculated such that the null point direction of the reception directivity of the reception antenna 13 matches the arrival direction of the wraparound wave.

When the switch 18 and the switch 20 are both set to the S2 side and the mode shifts to the normal operation mode, the weight control unit 44b is different from the radio relay apparatus 10a according to the second embodiment in the training operation mode. calculated complex weight W _i, that is, the complex weight W _i calculated as null point direction of reception directivity coincides with direction of arrival of the echo waves, fixedly multiplier 14-
i. That is, the wireless relay device 10a according to the second embodiment, when a transition to the normal operation mode has been started the wait control of the initial value of the complex weights W _i set in the training mode of operation, according to the third embodiment in the wireless relay device 10b, it continues to use fixedly complex weights W _i calculated in the training mode of operation in the normal operation mode.

In this way, it is possible to reduce the influence of the loop interference with a relatively simple circuit configuration and improve the characteristics of the radio relay device 10b.

Embodiment 4 FIG. 4 is a diagram showing a configuration of a wireless relay device according to Embodiment 4 of the present invention. In radio relay apparatus 10 according to Embodiment 1, reception antenna 13
Is configured using an adaptive array antenna, and the transmission antenna 24 is configured using other antennas. However, in the wireless relay apparatus 50 according to the third embodiment, the transmission antenna 55 is configured using the adaptive array antenna. It is characteristic in that it is configured. Other configurations are the same as those of the wireless relay device 10 according to the first embodiment, and the same reference numerals are given here, and detailed description is omitted.

Also in this radio relay apparatus 50, in the training operation mode, the switches 18 and 20
Are set to the S1 side, and the difference between the reference signal extracted by the despreading process in the multiplier 38 and the reference signal generated in the reference signal generation unit 30 is supplied to the weight control unit 46. You. Then, based on this error signal, the directivity of the transmission antenna 55 is adjusted so as to efficiently receive the loop interference wave.

[0073] Then, set the switch 18 and the switch 20 are both side S2, the process proceeds to the normal operation mode, is supplied to an adjusted complex weight W _i is the inverse characteristic section 44 in the training mode of operation, in the first embodiment
The same inverse characterization processing as in the case is performed. The inverse directivity weight _Winv generated by the inverse characterization processing is returned to the weight control unit 46. Then, the reverse directivity characteristic weight is supplied to the multiplier 56-i, and is temporarily fixed in that state.

In the normal operation mode, the difference between the pilot signal extracted by pilot signal extraction section 40 and the pilot signal generated by pilot signal generation section 42 is supplied to weight control section 46, and the temporarily fixed state is set. Is an initial value in weight control based on this error signal. Also in the weight control here, similarly to the first embodiment, the weight calculation is performed using the MMSE criterion, for example, by the LMS method, the RLS method, or the SMI method.

In this manner, the radiation directivity of the transmitting antenna 55 can be adjusted so as to reduce the intensity of the radio wave radiated in the direction from the transmitting antenna 55 to the receiving antenna 52. That is, the weight control unit 4
6 and the inverse characterization unit 44 obtain the optimum weight W _opt as so-called wraparound direction information in the training operation mode. Then, based on the wraparound direction information, a backward directivity characteristic weight _Winv is calculated so as to reduce the radiation intensity in the wraparound direction, and the radiation directivity of the transmitting antenna 55 is adjusted using this. By doing so, it is possible to sufficiently secure transmission / reception attenuation with respect to the wraparound wave, and to reduce the influence thereof.

Embodiment 5 FIG. 5 is a diagram showing a configuration of a wireless relay apparatus according to Embodiment 5 of the present invention. Radio relay apparatus 50a shown in FIG. 10 is characterized in that transmission antenna 55 is configured using an adaptive array antenna instead of transmission antenna 24, as compared with radio relay apparatus 10a according to the second embodiment. . Other configurations are the same as those of the wireless relay device 10a, and therefore, the same reference numerals are given here, and the detailed description is omitted.

In the radio relay apparatus 50a, the weight control section 46a sweeps the null point of the radiation directivity of the transmission antenna 55 in the normal training operation mode, and the reception level of the reference signal wrapping around from the transmission antenna 55 to the reception antenna 52 is reduced. Find out how it changes. Then, it is determined that the direction in which the reception level is minimum is the direction in which the signal passes from the transmitting antenna 55 to the receiving antenna 52. Then, the radiation directivity of the transmitting antenna 55 is adjusted so as to have a null point in the wraparound direction. In this case, a sufficient amount of attenuation between transmission and reception from the transmission antenna 55 to the reception antenna 52 can be ensured, and the influence of a loop wave can be reduced.

Embodiment 6 FIG. FIG. 6 is a diagram showing an overall configuration of a wireless relay device according to Embodiment 6 of the present invention. Radio relay apparatus 50b shown in FIG. 10 differs from radio relay apparatus 10b according to Embodiment 3 in that transmitting antenna 55 is configured using an adaptive array antenna instead of receiving antenna 13. Other configurations are the same as those of the wireless relay device 10b, and the same reference numerals are given here, and the detailed description is omitted.

In the wireless relay device 50b, the wireless relay device 5
Compared to 0a, complex weight W _i that is supplied to the multiplier 56-i is a point that is fixed in the normal operation mode differs. That is, in the wireless relay device 50b, the complex weight W calculated in the training operation mode is used.
_i is fixedly used in the normal operation mode. This makes it possible to reduce the influence of the loop wave with a simple configuration.

The radio relay apparatus according to the first to sixth embodiments described above can be variously modified.

For example, in the above description, the receiving antenna 13
Alternatively, an adaptive array antenna is used as one of the transmission antennas 55, but both antennas may be configured using an adaptive array antenna. In this way, it is possible to more appropriately secure the amount of attenuation between transmission and reception, and as a result, it is possible to prevent the wraparound wave from adversely affecting the characteristics of the wireless relay device.

In the above description, in the training operation mode, the reference signal subjected to the spread spectrum processing is transmitted from the transmitting antennas 24 and 55, and the received signals at the receiving antennas 13 and 52 are subjected to the despreading processing. Although the arriving wave arrival direction information and the wraparound direction information are obtained based on the despread signal, for example, when the influence of interference is small, the spectrum spread processing and the despread processing are omitted (multipliers 38 and 48). , Spread sequence generator 2
6. The synchronization supplement holding unit 28 may be omitted), and the wraparound arrival direction and the wraparound direction information may be obtained by checking the wraparound of the reference signal itself. In addition, wraparound arrival direction and wraparound direction information can be obtained by various methods.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a wireless relay device according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing a configuration of a wireless relay device according to Embodiment 2 of the present invention.

FIG. 3 is a diagram showing a configuration of a wireless relay device according to Embodiment 3 of the present invention.

FIG. 4 is a diagram showing a configuration of a wireless relay device according to Embodiment 4 of the present invention.

FIG. 5 is a diagram showing a configuration of a wireless relay device according to Embodiment 5 of the present invention.

FIG. 6 is a diagram showing a configuration of a wireless relay device according to Embodiment 6 of the present invention.

[Explanation of symbols]

10, 10a, 10b, 50, 50a, 50b wireless relay device, 12, 54 antenna elements, 13, 52 receiving antenna, 14, 38, 48, 56 multiplier, 16, 3
4,36 adders, 18,20 switches, 22 amplifiers, 24,55 transmitting antennas, 26 spreading sequence generators,
28 synchronization acquisition holding unit, 30 reference signal generation unit, 32
Delay circuit, 40 pilot signal extraction unit, 42 pilot signal generation unit, 44 inverse characterization unit, 46, 46a, 4
6b Weight control unit.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5J021 AA05 CA06 DB02 DB03 DB04 EA04 FA14 FA15 FA16 FA17 FA20 FA31 FA32 GA02 HA05 HA10 5K052 AA01 AA11 BB03 CC06 DD04 EE11 GG19 GG20 5K067 AA03 BB02 CC10 EE5 EE10 KK DD16 DD17 FF12 GG02 GG05 GG25 GG27 GG40

Claims (8)

[Claims] 1. A wireless relay apparatus comprising a transmitting antenna and a receiving antenna, amplifying a signal received by the receiving antenna and retransmitting the signal from the transmitting antenna, wherein the receiving antenna adjusts a reception directivity. A wraparound wave arrival direction detection means configured to detect arriving direction information of a wraparound wave from the transmission antenna to the reception antenna, and the reception to reduce reception sensitivity to the wraparound wave based on the arrival direction information. A radio repeater, comprising: a directivity adjustment unit that adjusts a reception directivity of an antenna. 2. The radio relay apparatus according to claim 1, wherein the wraparound wave arrival direction detecting means includes: a reference signal generating means for generating a predetermined reference signal; and a spread spectrum of the reference signal by a predetermined spreading code. Spread signal transmitting means for transmitting a spread signal from the transmitting antenna, and reference signal extracting means for extracting the reference signal by despreading the spread signal received by the receiving antenna with the spreading code, A wireless relay apparatus for detecting arrival direction information of the wraparound wave based on a reference signal extracted by the reference signal extracting means. 3. The radio relay apparatus according to claim 2, wherein the direction of arrival of the wraparound wave is determined by comparing a reference signal generated by the reference signal generation unit and a reference signal extracted by the reference signal extraction unit. Temporarily adjusting the reception directivity of the receiving antenna so that the difference is reduced, and including directivity temporary adjustment means for generating a result of the temporary adjustment as arrival direction information of the wraparound wave, wherein the directional adjustment means comprises: A directivity re-adjustment unit for re-adjusting the reception directivity of the reception antenna such that the signal level of the reference signal extracted by the reference signal extraction unit is reduced based on the result of the temporary adjustment as the arrival direction information of the wave. A wireless relay device characterized by the above-mentioned. 4. The radio relay apparatus according to claim 1, wherein said wraparound wave arrival direction detecting means comprises: signal transmitting means for transmitting a predetermined signal from said transmitting antenna; and said receiving antenna having a null point in a predetermined direction. Null point generating means for adjusting the reception directivity of the information, the predetermined direction is sequentially changed, the predetermined direction in which the signal level of the predetermined signal received by the reception antenna is minimized, and information for specifying the direction is determined. Wraparound direction sweep detection means for generating wake direction information of the wraparound wave, wherein the directivity adjustment means comprises a null point in a direction specified by the wraparound wave arrival direction information. A wireless relay device for adjusting reception directivity of an antenna. 5. A radio relay apparatus comprising a transmitting antenna and a receiving antenna, amplifying a signal received by the receiving antenna and retransmitting the signal from the transmitting antenna, wherein the transmitting antenna adjusts radiation directivity. A wraparound direction detecting unit configured to detect wraparound direction information corresponding to a wraparound direction from the transmission antenna to the reception antenna; and reducing a radiation intensity of a radio wave in the wraparound direction based on the wraparound direction information. And a directivity adjusting means for adjusting the radiation directivity of the transmission antenna. 6. The radio relay apparatus according to claim 5, wherein the wraparound direction detecting means includes: a reference signal generating means for generating a predetermined reference signal; and a spread signal obtained by spreading the reference signal with a predetermined spreading code. A spread signal transmitting unit for transmitting the reference signal from the transmitting antenna, and a reference signal extracting unit for extracting the reference signal by despreading the spread signal received by the receiving antenna with the spreading code. A wireless relay device for detecting the wraparound direction information based on a reference signal extracted by a signal extraction unit. 7. The wireless relay device according to claim 6, wherein the wraparound direction detecting unit determines a difference between a reference signal generated by the reference signal generating unit and a reference signal extracted by the reference signal extracting unit. Tentatively adjusting the radiation directivity of the transmission antenna so as to be smaller, and including directivity temporary adjustment means for generating a result of the temporary adjustment as the wraparound direction information, wherein the directional adjustment means comprises: Based on the results of the adjustment,
A wireless relay device comprising a directivity readjustment unit for readjusting the radiation directivity of the transmission antenna so that the signal level of the reference signal extracted by the reference signal extraction unit is reduced. 8. The radio relay apparatus according to claim 5, wherein the wraparound direction detecting means includes: signal transmitting means for transmitting a predetermined signal from the transmitting antenna; and radiation of the transmitting antenna so as to have a null point in a predetermined direction. Null point generating means for adjusting the directivity, including information for sequentially changing the predetermined direction, examining the predetermined direction in which the signal level of the predetermined signal received by the receiving antenna is minimal, and specifying the direction A wraparound direction sweep detecting means for generating the wraparound direction information, wherein the directivity adjustment means adjusts the radiation directivity of the transmitting antenna so as to have a null point in a direction specified by the wraparound direction information. A wireless relay device characterized by the above-mentioned.