JP4063385B2 - Wireless relay device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a radio relay apparatus that relays signals, such as a mobile phone, and more particularly to a radio relay apparatus that can suppress wraparound interference.
[0002]
[Prior art]
In recent years, wireless communication systems such as mobile phones have become widespread, but due to conditions such as surrounding buildings, there are scattered areas where the radio waves of the base station do not reach directly, and you want to use mobile phones even in such places In response to this voice, a wireless relay device that relays the signal of the base station is installed to cover the above zone.
[0003]
In general, a radio relay apparatus includes two antennas and a relay amplifier, receives a signal arriving from a base station by a receiving antenna, amplifies the signal by a relay amplifier, and transmits the signal from a transmitting antenna. .
[0004]
[Problems to be solved by the invention]
However, in the conventional wireless relay device, high-frequency coupling may occur between the receiving antenna and the transmitting antenna. When the coupling becomes stronger than a certain level, the wireless relay device is separated from the transmitting antenna. There was a problem that the signal to be transmitted and output circulated to the receiving antenna and caused oscillation.
[0005]
In view of this, measures are taken to prevent the signal transmitted to the receiving antenna from being circulated, for example, by providing a sufficient distance between the receiving antenna and the transmitting antenna.
[0006]
However, it is difficult to secure a place for installing the wireless relay device in a densely populated area such as a city center, and it is difficult to secure a sufficient distance between the two antennas due to the restrictions on the location. The current situation is.
[0007]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a radio relay apparatus that can suppress wraparound interference waves even when the distance between antennas is shortened.
[0009]
[Means for Solving the Problems]
Above prior art the present invention for solving the problems is the non-linear switching device, and a receiving antenna in which a plurality of antenna elements in an array, provided in correspondence to the antenna elements, the corresponding antenna element A phase control circuit that controls the phase of the signal arriving at the phase, an amplitude control circuit that is provided corresponding to the phase control circuit and controls the amplitude of the signal input from the corresponding phase control circuit, and the amplitude control circuit A combining unit that combines the input signals; a signal that is output from the combining unit; a receiving unit that outputs the level of the signal as a reception level; and a signal that is input from the receiving unit has a specific gain The variable gain repeater amplifier that amplifies the signal, the transmission antenna that radiates the signal input from the variable gain repeater amplifier, and initially the variable gain repeater amplifier is turned off. The signal arriving at the receiving antenna is limited to the desired wave, and the phase control circuit and the amplitude control circuit are controlled to check the condition that the reception level input from the receiving unit is maximized. Next, the variable gain repeater amplifier is turned on, and the gain level is gradually increased while controlling the phase control circuit and the amplitude control circuit so that the reception level input from the receiving unit is maximized. And detecting the arrival direction of the interference wave, based on the arrival direction of the desired wave and the arrival direction of the interference wave, and calculating the weighting coefficient of the receiving antenna for suppressing the interference wave, A control unit that controls the phase control circuit and the amplitude control circuit so as to receive the desired wave according to the weighting coefficient is provided, and interference waves can be suppressed even if the distance between the antennas is shortened.
[0010]
Incidentally, when the frequency of the signal to be relayed is high, in the non-line repeater, receiver, and a receiving unit that outputs to the variable gain amplifier repeater demodulates the input signal, variable gain amplifier, the receiving It is preferable to re-modulate the signal input from the unit, amplify the signal with a specific gain, and radiate the signal via a transmission antenna.
[0011]
Further, when the frequency of the signal to be relayed is not so high, in the non-line repeater, receiver, and a receiving unit that outputs without demodulating the input signal to the variable gain amplifier repeater, the variable gain amplifier It is preferable to use a variable gain relay amplifier that amplifies a signal input from the receiving unit with a specific gain and then radiates the signal as it is through a transmitting antenna.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
A radio relay apparatus according to an embodiment of the present invention includes an array-shaped receiving antenna, detects a direction from which a signal from a base station arrives and a direction from which an interference wave arrives, and based on information on these directions. Thus, the interference wave is suppressed by calculation, and the wraparound interference wave can be suppressed even if the distance between the antennas is shortened.
[0013]
As shown in FIG. 1, a radio relay apparatus (this apparatus) according to an embodiment of the present invention includes a reception antenna 1, a phase control unit 2, an amplitude control unit 3, a synthesis unit 4, and a reception unit 5. And a control unit 6, a variable gain relay amplifier 7, and a transmitting antenna 8. FIG. 1 is a configuration block diagram of the apparatus.
[0014]
Hereinafter, each part is demonstrated concretely.
The receiving antenna 1 has a plurality of antenna elements arranged in an array.
[0015]
Here, specifically, the array shape means that the antenna elements are arranged on the line with a constant interval d as shown in FIG. 3A, and as shown in FIG. It can be considered that they are arranged at a constant interval d on the circumference. FIG. 3 is a perspective view showing a specific appearance of the receiving antenna 1.
Here, the interval d is generally set to a fraction of 1 to 1 wavelength.
[0016]
The phase control unit 2 includes a phase control circuit corresponding to each antenna element of the receiving antenna 1, receives a signal arriving at each antenna element of the corresponding receiving antenna 1, and controls the control unit 6 described later. The phase of the received signal (reception signal) is controlled in accordance with an instruction input from.
[0017]
The amplitude control unit 3 includes an amplitude control circuit corresponding to the phase control circuit of the phase control unit 2, and signals input from the corresponding phase control circuits in response to instructions input from the control unit 6 described later. It controls the amplitude.
[0018]
The synthesizer 4 synthesizes and outputs the signals input from the amplitude controller 3 and output from each amplitude control circuit.
[0019]
The receiving unit 5 measures the level of the signal input from the synthesizing unit 4 and outputs it to the control unit 6 as a reception level, that is, RSSI (Receiving Signal Strength Indicator).
[0020]
The control unit 6 outputs instructions to the phase control unit 2 and the amplitude control unit 3 based on the RSSI input from the reception unit 5.
The control unit 6 turns on or off the variable gain repeater amplifier 7 and controls the gain of the variable gain repeater amplifier 7.
The operation of the control unit 6 will be described in detail later.
[0021]
The variable gain relay amplifier 7 amplifies and outputs the signal input from the receiving unit 5.
The transmitting antenna 8 radiates the signal output from the variable gain relay amplifier 7 to the outside.
[0022]
The receiving unit 5 may include a demodulation circuit and demodulate the signal input from the combining unit 4.
The variable gain relay amplifier 7 in this case amplifies the demodulated signal, remodulates it, and outputs it.
[0023]
Here, the operation of the control unit 6 will be described with reference to FIG. FIG. 2 is a flowchart showing specific processing of the control unit 6.
[0024]
First, the controller 6 turns off the variable gain relay amplifier 7 (S1).
Then, the control unit 6 controls the phase control unit 2 and the amplitude control unit 3, while the condition that the RSSI input from the reception unit 5 is maximized (the phase control state of each phase control circuit and each amplitude control). The state of the amplitude control of the circuit) is examined, and the direction in which the RSSI of the signal (desired wave) arriving at the first antenna 1 is maximized is detected (S2).
[0025]
When the direction in which the RSSI of the signal (desired wave) arriving at the first antenna 1 is maximized is detected, the control unit 6 turns on the variable gain relay amplifier 7 (S3).
Then, while gradually increasing the gain of the variable gain relay amplifier 7, the direction in which the RSSI of the signal (interference wave) that travels from the second antenna 8 to the first antenna 1 is maximized in the same manner as in the process S 2. Detect (S4).
[0026]
Then, the direction of the desired wave arriving at the first antenna 1 (hereinafter referred to as “desired wave direction”) detected in the process S2 and the direction of the interference wave arriving at the first antenna detected in the process S4. (Hereinafter, referred to as “interference wave direction”), so that the RSSI of the desired wave arriving at the first antenna 1 again is maximized under the condition that the interference wave direction is a null point. 2 and the amplitude controller 3 are controlled (S5), and the process is terminated.
[0027]
Here, the specific contents of the process of maximizing the RSSI of the desired wave under the condition that the interference wave direction is the null point in the processes S2 to S5 will be described.
[0028]
Here, in order to simplify the description, a case where the number of elements of the receiving antenna is two will be described as an example.
In the following description, equivalent baseband complex signals of the desired wave and the wraparound wave received by the first antenna element are respectively represented by r11 and r12, and the desired wave and the interference wave received by the second antenna element. Let the equivalent baseband complex signals be r21 and r22, respectively. Here, the relative phase relationship between rll, r12, r21, and r22 can be estimated based on the desired wave direction obtained in process S2 and the interference wave direction obtained in process S4. Hereinafter, an example of the estimation method will be described.
[0029]
When the control unit 6 controls the phase weighting unit 2 and the amplitude control unit 3 to set the complex weighting coefficients of the respective antenna elements as w1 and w2, the desired wave component c1 and the interference wave component at the output of the combining unit 4 c2 has a relationship represented by the calculation of the following [Equation 1] matrix.
[0030]
[Expression 1]
[0031]
In [Equation 1], if the condition where the desired wave component is not zero and the interference wave component is zero, that is, w1 and w2 are solved with c1 ≠ 0 and c2 = 0, only the desired wave is received and the interference wave is received. It is possible to obtain complex weighting coefficients (w1, w2) that can suppress.
[0032]
However, in reality, since the elements of the matrix shown in [Equation 1] cannot be directly observed, a set of w1 and w2 such that c2 = 0 is searched for by the processes S2 to S4. Here, since c2 is a signal radiated from the transmitting antenna 8 of this apparatus, the level of c2 that has entered the receiving antenna 1 can be estimated by mutual processing or the like.
[0033]
In general, at the stage where w1 and w2 are not adjusted, the level of c2 is significantly higher than the level of c1, that is, it is considered that the relationship of the following [Equation 2] exists.
[0034]
[Expression 2]
[0035]
Therefore, in the processes S2 to S4, a set of w1 and w2 may be searched so that the level of the signal arriving at the receiving antenna 1 is minimized.
[0036]
Even when the number of antenna elements is N, as can be easily inferred from this example, if the desired wave direction and the interference wave direction are different, the (N-1) interference wave is suppressed and only the desired wave is transmitted. The coefficients w1, w2,..., WN can be uniquely determined to receive.
[0037]
According to this apparatus, even if an interference wave wraps around the reception antenna, the control unit can suppress the interference wave and receive the desired wave, and the distance between the reception antenna and the transmission antenna can be reduced. Even if it is shortened, there is an effect that the wraparound interference wave can be suppressed.
[0039]
【The invention's effect】
According to the onset bright, the phase and amplitude of each incoming signals of a plurality of antenna elements arranged in an array, each the corresponding phase control circuit and the amplitude control circuit controls the synthesis unit is the control The receiver unit outputs the synthesized signal, and outputs the level of the signal as a reception level. The variable gain relay amplifier amplifies the signal input from the receiver unit with a specific gain. , The transmission output through the transmission antenna, the control unit initially turns off the variable gain relay amplifier, controls the phase control circuit and the amplitude control circuit, the reception level input from the reception unit is maximized Check the conditions, detect the direction of arrival of the desired wave, then turn on the variable gain repeater amplifier and gradually increase the gain of the amplification while controlling the phase control circuit and the amplitude control circuit. Input The arrival level of the interference wave is detected, the weighting coefficient for suppressing the interference wave is calculated based on the detected direction, and the phase control circuit and the amplitude are determined according to the weighting coefficient. Since the wireless relay device controls the control circuit, even if the distance between the receiving antenna and the transmitting antenna is shortened, there is an effect that interference waves can be suppressed by weighting at the time of reception.
[Brief description of the drawings]
FIG. 1 is a configuration block diagram of the apparatus.
FIG. 2 is a flowchart showing specific processing of a control unit 6;
FIG. 3 is a perspective view showing a specific external appearance of the receiving antenna 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Reception antenna, 2 ... Phase control part, 3 ... Amplitude control part, 4 ... Synthesis | combination part, 5 ... Reception part, 6 ... Control part, 7 ... Variable gain relay amplifier, 8 ... Transmission antenna

Claims (3)

  A receiving antenna in which a plurality of antenna elements are arranged in an array, a phase control circuit that is provided corresponding to the antenna element and controls the phase of a signal arriving at the corresponding antenna element, and corresponds to the phase control circuit An amplitude control circuit for controlling the amplitude of a signal input from a corresponding phase control circuit, a synthesis unit for synthesizing a signal input from the amplitude control circuit, and a signal input from the synthesis unit And a receiving unit that outputs the level of the signal as a reception level, a variable gain relay amplifier that amplifies the signal input from the receiving unit with a specific gain, and a signal input from the variable gain relay amplifier. The transmitting antenna and the variable gain repeater amplifier are initially turned off, the signal arriving at the receiving antenna is limited to the desired wave, and the phase control circuit and the And control the control circuit to check the condition that the reception level input from the receiving unit is maximum, detect the direction of arrival of the desired wave, then turn on the variable gain repeater amplifier, and increase the gain of amplification. While gradually increasing, the phase control circuit and the amplitude control circuit are controlled to check the condition that the reception level inputted from the receiving unit becomes maximum, the arrival direction of the interference wave is detected, and the desired wave Based on the arrival direction and the arrival direction of the interference wave, the weighting coefficient of the receiving antenna for suppressing the interference wave is calculated, and the phase control circuit and the amplitude control circuit are configured to receive the desired wave according to the weighting coefficient. And a control unit that controls the wireless relay device. The receiving unit is a receiving unit that demodulates the input signal and outputs the demodulated signal to the variable gain relay amplifier, and the variable gain amplifier remodulates the signal input from the receiving unit, amplifies it with a specific gain, 2. The radio relay apparatus according to claim 1 , wherein the radio relay apparatus is a variable gain relay amplifier that radiates through a transmitting antenna. The receiving unit is a receiving unit that outputs the input signal to the variable gain repeater amplifier without demodulating the amplified signal. The variable gain amplifier amplifies the signal input from the receiving unit with a specific gain and then directly transmits the amplified signal. 2. The radio repeater according to claim 1 , wherein the radio repeater is a variable gain repeater amplifier that radiates through a trusted antenna.

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