JP2003092549A - Radio base device, and method and program for transmission directivity calibration - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio base device capable of calibrating another terminal with spatial multiplex, and to provide a method for calibrating transmission directivity of a terminal and a calibration program. SOLUTION: An adaptive base station 2 uses two antennas 23 and 24 to transmit/receive a signal to/from one antenna terminal 1 and also uses two antennas 21 and 22 to send a desired signal to an adaptive array terminal 3 to be a calibration target while directing null to the terminal 1. The signal from the antennas 23 and 24 to the terminal 1 becomes an interference signal to the terminal 3. The terminal 3 transmits a signal with transmission directivity for directing beams and null to desired signal sources 21 and 22 interference signal sources 23 and 24 on the basis of receiving weight, and the base station 2 measures a DU ratio. The terminal 3 corrects receiving weight so as to obtain an optimum DU ratio.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a radio base unit,
TECHNICAL FIELD The present invention relates to a transmission directivity calibration method and a transmission directivity calibration program, and particularly to an adaptive array base station for performing calibration of the transmission directivity of an adaptive array terminal, and a transmission directivity calibration in such an adaptive array base station. A method and a transmission directivity calibration program.

[0002]

2. Description of the Related Art In recent years, in mobile communication systems (for example, Personal Handyphone System: PHS) which are rapidly developing, the same time slot of the same frequency is spatially arranged in order to increase the frequency utilization efficiency of radio waves. A PDMA (Path Division Multiple A) that allows multiple mobile wireless terminal devices (hereinafter, terminals) to be spatially multiplex-connected to a wireless base device (hereinafter, base station) by division
ccess) method has been proposed.

In this PDMA system, the adaptive array technology is currently used. Adaptive array processing is to accurately extract the signal from the desired terminal by calculating and controlling the weight vector consisting of the reception coefficient (weight) for each antenna of the base station based on the received signal from the terminal and applying and controlling it. It is a process to do.

By such an adaptive array processing, the uplink signal from the antenna of each user terminal is received by the array antenna of the base station, and separated and extracted with the reception directivity by the reception weight of the user terminal.

Further, assuming that the time difference between reception and transmission at the base station is 0, there is no fluctuation in the propagation path (section between the antenna end of the base station and the antenna end of the terminal), and thus the base station The downlink signal from the terminal to the terminal is transmitted from the array antenna of the base station with the transmission directivity to the antenna of the terminal by applying the reception weight obtained at the time of reception as the transmission weight information.

Such an adaptive array processing is a well-known technique. For example, "Adaptive Signal Processing by Array Antenna" by Kikuma Nobuyoshi (Science and Technology Publication), pages 35 to 49, "Chapter 3 MMSE Adaptive Array" Since it has been described in detail, the description of its operating principle is omitted here.

In the following description, a base station that performs downlink transmission directivity control for a terminal using such adaptive array processing is called an adaptive array base station.

On the other hand, there has been developed a wireless terminal device for forming a reception directivity and a transmission directivity by using such an adaptive array processing to transmit and receive a signal. Hereinafter, a terminal that performs directivity control using such an adaptive array process is referred to as an adaptive array terminal.

However, in these adaptive array base station and adaptive array terminal, even if there is no fluctuation in the propagation path, as described above, the reception signal path and the transmission signal path in the adaptive array base station or in the adaptive array terminal are Phase difference between the received and transmitted signal paths due to the physical difference between the received signal path and the transmitted signal path (for example, the difference in path length, the difference in characteristics of devices such as amplifiers and filters included in the receiving and transmitting circuits). Therefore, a difference in transmission characteristics such as the amount of amplitude fluctuation will occur.

If there is a difference in transmission characteristics between transmitted and received signals within the adaptive array base station or within the adaptive array terminal, the method of using the reception weight as it is as the transmission weight as described above is used for the terminal or base station of the transmission destination. It becomes impossible to direct the optimum transmission directivity.

For this reason, normally, at the time of factory shipment, calibration for compensating the difference between the transmission characteristics of the reception signal path and the transmission characteristics of the transmission signal path in the base station or the terminal to form the optimum transmission directivity. Is performed.

However, the characteristics of the devices included in the receiving circuit and the transmitting circuit in the base station or the terminal are different from those at the time of shipment due to aging and temperature changes. It is necessary to perform the calibration process.

For such calibration processing in the installed base station, for example, international publication number W
It is disclosed in, for example, O00 / 08777 (International Publication Date: February 17, 2000). In such a conventional method, for example, by transmitting a known signal from one of the plurality of antennas forming the array antenna of the adaptive array base station and receiving the known signal in an array from the remaining antennas, In the base station, calibration processing is performed to optimize the transmission directivity by measuring and compensating for the difference between the transmission characteristics of the reception signal path and the transmission characteristics of the transmission signal path. Further, even in the adaptive array terminal, the calibration process by the same method can be considered.

[0014]

As described above, with respect to the adaptive array terminal after the start of use, it is conceivable that the calibration processing is performed by each terminal alone.

In this method, the transmission characteristic of the reception signal path and the transmission characteristic of the transmission signal path in the adaptive array terminal are changed while sequentially changing the combination of the antenna for transmitting a known signal and the antenna for receiving the known signal. Since the compensation of the difference is repeated, the following problems occur.

That is, since it takes time for the entire calibration process because the compensation is repeated, and the array reception is performed by the remaining number of antennas except the antenna transmitting the known signal, the entire array antenna receives the signals. There is a problem that the adaptive array performance of the terminal, that is, the calibration performance is deteriorated as compared with the case of performing the above.

Furthermore, since short-distance signal transmission / reception is performed between antennas of a single terminal, the following problems occur.

That is, power control for transmission and reception is required so that signals are not saturated, and control is complicated. Also,
If the distance between the transmitting antenna and the receiving antenna is too short, it becomes difficult to form a directional pattern having sufficient resolution (for example, beam and null sharpness), and there is a problem that the adaptive array performance deteriorates.

Therefore, an object of the present invention is to use all the antennas of the adaptive array terminal for receiving a known transmission signal from the outside, thereby making it possible to perform a complicated control within the adaptive array terminal in a short time. And a radio base device capable of performing highly accurate calibration processing of transmission directivity of an adaptive array terminal,
A transmission directivity calibration method and a transmission directivity calibration program are provided.

Another object of the present invention is even when a terminal other than the adaptive array terminal to be calibrated is connected to the adaptive array radio base station for calibrating the adaptive array terminal. A wireless base device capable of performing a transmission directivity calibration process of an adaptive array terminal, a transmission directivity calibration method, and a transmission directivity calibration program.

[0021]

According to one aspect of the present invention, there is provided a radio base station for performing communication with a radio terminal apparatus by adaptive array processing using a first plurality of antennas, wherein Means for communicating with an arbitrary wireless terminal device using at least a part of one plurality of antennas, and a specific wireless terminal device for communicating with a wireless base device by adaptive array processing using the second plurality of antennas And a means for dividing the first plurality of antennas into a third plurality of antennas and a fourth plurality of antennas in a calibration multiplex mode for performing the calibration, and an arbitrary radio using the third plurality of antennas. Means for continuing communication with the terminal device, and means for forming transmission directivity for directing null to an arbitrary wireless terminal device by using the fourth plurality of antennas Means for transmitting a desired signal to a specific wireless terminal device at the same frequency and time slot used for communication with an arbitrary wireless terminal device with the formed transmission directivity; And means for generating information about the reception levels of the signals received by the plurality of antennas and the signals received by the fourth plurality of antennas, and for the transmission directivity calibration in the specific wireless terminal device. And means for transmitting information regarding the reception level to a specific wireless terminal device.

According to the present invention, even when any wireless terminal device other than the adaptive array terminal to be calibrated is connected to the adaptive array wireless base device, the space between the adaptive array wireless base device and the arbitrary wireless terminal device is The calibration processing of the transmission directivity of the adaptive array wireless terminal device can be performed while maintaining the multiple connection.

[0023] Preferably, the radio base unit further includes means for continuing the transmission of the desired signal and the transmission of the information regarding the reception level until a specific radio terminal device instructs to end the calibration.

[0024] Preferably, the means for generating the information on the reception level includes the reception response vector of the signal from the specific wireless terminal device received by the third plurality of antennas and the specific reception response vector received by the fourth plurality of antennas. A means for calculating a reception response vector of a signal from the wireless terminal device, and a reception level ratio of the third plurality of antennas and the fourth plurality of antennas based on the calculated reception response vector,
And means for supplying it as information regarding the reception level.

Preferably, the means for forming the transmission directivity is based on the means for calculating the reception response vector of the signal from the arbitrary wireless terminal device received by the fourth plurality of antennas, and the calculated reception response vector. And means for calculating a transmission weight for forcibly directing null to any wireless terminal device.

Another aspect of the present invention is a transmission directivity calibration method for a wireless terminal device in a wireless base device which communicates with a wireless terminal device by adaptive array processing using a first plurality of antennas, In the normal mode, a step of communicating with an arbitrary wireless terminal device using at least a part of the first plurality of antennas, and a communication with a wireless base device by adaptive array processing using the second plurality of antennas Splitting the first plurality of antennas into a third plurality of antennas and a fourth plurality of antennas in a calibration multiplex mode for calibrating a specific wireless terminal device;
Using the third plurality of antennas to continue communication with an arbitrary wireless terminal device, and using the fourth plurality of antennas to form a transmission directivity in which null is directed to the arbitrary wireless terminal device. A step of transmitting a desired signal to a specific wireless terminal device in the same frequency and time slot used for communication with an arbitrary wireless terminal device with the formed transmission directivity; 3 for generating information about reception levels of a signal received by a plurality of antennas and a signal received by a fourth plurality of antennas, and for generating transmission directivity calibration in a specific wireless terminal device. And transmitting information regarding the reception level to a specific wireless terminal device.

According to the present invention, even when an arbitrary wireless terminal device other than the adaptive array terminal to be calibrated is connected to the adaptive array wireless base device, the space between the adaptive array wireless base device and the arbitrary wireless terminal device is connected. The calibration processing of the transmission directivity of the adaptive array wireless terminal device can be performed while maintaining the multiple connection.

Preferably, the calibration method is
The method further includes the step of continuing the transmission of the desired signal and the transmission of the information on the reception level until the specific wireless terminal device instructs the end of the calibration.

Preferably, the step of generating the information on the reception level includes the reception response vector of the signal from the specific wireless terminal device received by the third plurality of antennas and the specific reception response vector received by the fourth plurality of antennas. Calculating a reception response vector of a signal from the wireless terminal device, and calculating a reception level ratio of the third plurality of antennas and the fourth plurality of antennas based on the calculated reception response vector, and receiving Providing as information about the level.

Preferably, the step of forming the transmission directivity is based on the step of calculating the reception response vector of the signal from the arbitrary wireless terminal device received by the fourth plurality of antennas, and based on the calculated reception response vector. And forcibly directing a null to any wireless terminal device.

Yet another aspect of the present invention is a transmission directivity calibration program for a wireless terminal device in a wireless base device that communicates with a wireless terminal device by adaptive array processing using a first plurality of antennas. , A step of making a computer communicate with an arbitrary wireless terminal device by using at least a part of the first plurality of antennas in a normal mode, and a wireless base device by adaptive array processing using the second plurality of antennas. A step of dividing the first plurality of antennas into a third plurality of antennas and a fourth plurality of antennas in a calibration multiplex mode for calibrating a specific wireless terminal device that performs communication A step of continuing communication with an arbitrary wireless terminal device using a plurality of antennas; Using the antenna to form a transmission directivity that directs null to any wireless terminal device, and with the formed transmission directivity, at the same frequency and time slot used for communication with any wireless terminal device. ,
Transmitting a desired signal to a specific wireless terminal device, and generating information regarding reception levels of a signal received by the third plurality of antennas and a signal received by the fourth plurality of antennas from the specific wireless terminal device. The step and the step of transmitting the generated information regarding the reception level to the specific wireless terminal device for the calibration of the transmission directivity in the specific wireless terminal device are performed.

According to the present invention, even if any wireless terminal device other than the adaptive array terminal to be calibrated is connected to the adaptive array wireless base device, the space between the adaptive array wireless base device and the wireless array device is arbitrary. The calibration processing of the transmission directivity of the adaptive array wireless terminal device can be performed while maintaining the multiple connection.

Preferably, the calibration program further causes the step of continuing the transmission of the desired signal and the transmission of the information regarding the reception level until a specific wireless terminal device instructs the end of the calibration.

Preferably, the step of generating the information on the reception level includes the reception response vector of the signal from the specific wireless terminal device received by the third plurality of antennas and the specific reception vector of the signal received by the fourth plurality of antennas. Calculating a reception response vector of a signal from the wireless terminal device, and calculating a reception level ratio of the third plurality of antennas and the fourth plurality of antennas based on the calculated reception response vector, and receiving Providing as information about the level.

Preferably, the step of forming the transmission directivity is based on the step of calculating the reception response vector of the signal from the arbitrary wireless terminal device received by the fourth plurality of antennas, and the calculated reception response vector. And forcibly directing a null to any wireless terminal device.

Yet another aspect of the present invention is a transmission directivity calibration method for a wireless terminal device in a wireless base device which communicates with a wireless terminal device by adaptive array processing using a first plurality of antennas. ,
In the normal mode, a step of communicating with an arbitrary wireless terminal device using at least a part of the first plurality of antennas, and a communication with a wireless base device by adaptive array processing using the second plurality of antennas A step of dividing the first plurality of antennas into a third plurality of antennas and a fourth plurality of antennas in a calibration multiplex mode for calibrating a specific wireless terminal device; And using the fourth plurality of antennas to form a transmission directivity that directs null to the arbitrary wireless terminal device, and the formed transmission directivity. Therefore, a desired signal for a specific wireless terminal device can be transmitted in a fourth signal at the same frequency and time slot used for communication with an arbitrary wireless terminal device. Transmitting based on a desired signal from the fourth plurality of antennas and a signal transmitted from the third plurality of antennas, which is received by the second plurality of antennas in a specific wireless terminal device Calculating weight information for forming a transmission directivity pattern in which a beam is directed to a fourth plurality of antennas and a null is directed to a third plurality of antennas; and a step of correcting the calculated weight information. A step of transmitting a predetermined signal from the specific wireless terminal device to the wireless base device in a transmission directivity pattern based on the corrected weight information; and a predetermined signal received from the specific wireless terminal device at the third plurality of antennas. A step of generating information about a reception level with respect to a predetermined signal received by a fourth plurality of antennas; Transmitting the generated reception level information to a specific wireless terminal device for calibration of signal directivity, and receiving at the wireless base device based on the reception level information received at the specific wireless terminal device. And a step of determining a correction value of the weight information that optimizes the level information.

According to the present invention, even when an arbitrary wireless terminal device other than the adaptive array terminal to be calibrated is connected to the adaptive array wireless base device, the space between the adaptive array wireless base device and the arbitrary wireless terminal device is The calibration processing of the transmission directivity of the adaptive array wireless terminal device can be performed while maintaining the multiple connection.

Preferably, the calibration method is
The method further includes the step of continuing the transmission of the desired signal and the transmission of the information on the reception level until the specific wireless terminal device instructs the end of the calibration.

[0039] Preferably, the step of generating the information about the reception level includes the reception response vector of the signal from the specific wireless terminal device received by the third plurality of antennas and the specific reception response vector received by the fourth plurality of antennas. Calculating a reception response vector of a signal from the wireless terminal device, and calculating a reception level ratio of the third plurality of antennas and the fourth plurality of antennas based on the calculated reception response vector, and receiving Providing as information about the level.

[0040] Preferably, the step of calculating the reception level ratio includes the step of supplying an average of the reception level ratios over a predetermined period as the calculated reception level ratio.

Preferably, the step of forming the transmission directivity is based on the step of calculating the reception response vector of the signal from the arbitrary wireless terminal device received by the fourth plurality of antennas, and the calculated reception response vector. And forcibly directing a null to any wireless terminal device.

[0042]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will now be described in detail with reference to the drawings. It should be noted that the same or corresponding parts in the drawings are designated by the same reference numerals and the description thereof will not be repeated.

1 to 3 are conceptual diagrams schematically showing the principle of a transmission directivity calibration method for an adaptive array terminal according to an embodiment of the present invention.

The present invention does not perform calibration processing by each adaptive array terminal alone as described above, but by exchanging signals with an external adaptive array base station, the transmission direction of the adaptive array terminal is improved. The calibration processing of the sex is performed.

Particularly in the embodiment shown in FIGS. 1 to 3,
Even if another terminal is spatially multiplexed in a time slot for calibrating the adaptive array terminal by exchanging signals with an external adaptive array base station having at least four antennas, the adaptive array terminal This enables the calibration processing of the transmission directivity of the array terminal.

The principle of the transmission directivity calibration method of the adaptive array terminal according to the embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, the wireless device 1 is a normal single-antenna terminal that is not the target of the calibration process, and the wireless device 2 is an adaptive array base station communicating with the terminal 1. .

The signal transmitted from the antenna 11 of the single-antenna terminal 1 includes at least four antennas 21 and 2 which form an array antenna of the adaptive array base station 2.
The signals from the antenna 11 are separated and extracted in a reception directivity pattern as shown by the solid line, based on the reception weights obtained by the array reception by 2, 23 and 24 and obtained as a result of the adaptive array processing.

The adaptive array base station 2 which performs array processing by using all four antennas as described above cannot be used as it is for calibration of other adaptive array terminals.

Therefore, in the embodiment of the present invention, FIG.
According to the principle shown in the conceptual diagram of FIG. 3, the calibration of the other calibration terminals to be calibrated is executed while maintaining the spatial multiplexing connection with the terminal 1.

In FIG. 2, the wireless device 3 is an adaptive array terminal which is the target of the calibration process. In response to the calibration request from the adaptive array terminal 3, the adaptive array base station 2 forms a directivity pattern for one antenna terminal 1 using at least two antennas 23 and 24, and at least two antennas 21 and 22 is used to switch the control in the base station 2 so as to form a directivity pattern for the adaptive array terminal 3 and start the calibration process.

More specifically, for the single-antenna terminal 1, as shown by the solid line in FIG. 2, the transmission directivity pattern in which the beam is directed to the antenna 11 of the terminal 1 is that of the adaptive array base station 2. It is formed by array processing by the antennas 23 and 24.

On the other hand, for the adaptive array terminal 3, as shown by the broken line in FIG. 2, the transmission directivity pattern in which the null is forcibly directed to the antenna 11 of the terminal 1 is the antenna of the adaptive array base station 2. 21,22
It is formed by the array processing by.

As a result, the adaptive array base station 2
A known signal having the same frequency as a predetermined frequency used for communication with the terminal 1, which is a desired signal for the terminal 3, is transmitted from the two antennas 21 and 22 of The signal of the above-mentioned predetermined frequency transmitted to 1 becomes an interference signal for the terminal 3.

These transmission signals are array-received by at least two antennas 31 and 32 forming the array antenna of the adaptive array terminal 3, and based on the reception weight obtained as a result of the adaptive array processing,
Desired signals from the antennas 21 and 22 of the base station 2 are separated and extracted in the reception directivity pattern as shown in the figure.

In the adaptive array terminal 3, the reception weight obtained at the time of such reception is multiplied by a certain correction value and used for forming transmission directivity described later.

Next, as shown in FIG. 3, the adaptive array terminal 3 uses the reception weight obtained at the time of reception and multiplied by the above-mentioned correction value as the transmission weight to form the transmission directivity pattern as shown in the figure. Then, a signal is transmitted to the adaptive array base station 2. As shown in the figure, the transmission directivity pattern formed based on the transmission weight using the reception weight is the antenna 2 of the antenna of the adaptive array base station 2 that transmits the desired signal.
The beams are directed to the antennas 1 and 22, and the nulls are directed to the antennas 23 and 24 which have transmitted the interference signals.

The adaptive array base station 2 uses two antennas 21 and 22 to adaptively transmit a beam signal (desired signal) from the adaptive array terminal 3 and a null signal (interference signal) from the single antenna terminal 1. The received response vector of the terminal 3 (Desired user's wav
e: hereinafter, D wave) is calculated.

On the other hand, the adaptive array base station 2
The two antennas 23 and 24 adaptively receive the beam signal (desired signal) from the one-antenna terminal 1 and the null signal (interference signal) from the adaptive array terminal 3 and receive the reception response vector (Undesired signal) of the terminal 3. use
r's wave: U wave).

In the adaptive array base station 2, the magnitudes of these reception response vectors (D wave and U wave) are calculated, and the ratio is DU (Desired user's power:
Calculate the Undesired user's power) ratio. In other words, this DU ratio represents the depth of the null in the shape of the transmission directivity pattern for the adaptive array base station 2.

The higher the accuracy of the transmission directivity pattern of the adaptive array terminal 3, the more adaptive array base station 2
Beam to the antennas 21 and 22 of
For 3 and 24, the nulls will be oriented more accurately (ie the nulls will be deeper) and the antennas 21,
The received power at 22 increases and the received power at antennas 23 and 24 decreases. That is, the DU ratio becomes high.

From this fact, the DU ratio measured by the adaptive array base station 2 can be used as an index indicating whether or not the transmission directivity is accurately formed in the adaptive array terminal 3. That is, if the correction value by which the reception weight is multiplied in the adaptive array terminal 3 is determined so that the DU ratio measured by the adaptive array base station 2 becomes optimum (highest), the calibration of the transmission directivity of the adaptive array terminal 3 is performed. Has been performed.

The received power of each antenna is calculated by the terminal 1
Since the received power from the terminal is also included, D for the terminal 3 only
D is calculated directly from the received power of each antenna to obtain the U ratio.
Instead of obtaining the U ratio, the DU ratio is calculated from the reception response vector of the terminal 3.

FIG. 4 is a timing chart showing the procedure of the transmission directivity calibration method according to the embodiment shown in FIGS.

Referring to FIG. 4, the operation of the adaptive array terminal 3 to be calibrated is shown on the left side, and the adaptive array having at least four antennas as an external radio device for performing the calibration is shown on the right side. The operation of the base station 2 is shown.

A specific procedure of the calibration method according to the embodiment of the present invention will be described with reference to FIG.

First, on the terminal side, it is judged whether or not the conditions for starting the calibration are satisfied (step S1). Here, the calibration start condition is, for example, that the calibration timer that measures the elapse of a predetermined period from the time of executing the last calibration has expired, or that the temperature has changed from the time of executing the last calibration. Is detected, it is determined that the communication quality is deteriorated due to the deterioration of the transmission directivity based on the number of interference avoiding operations (for example, a channel switching request from the base station), and the like.

When it is determined in step S1 that any of these conditions is satisfied, the calibration is started on the terminal side, and in step S2, it is determined whether or not the measurement condition for calibration is satisfied. Is determined. Here, when the terminal monitors the surrounding radio wave environment and determines that there are few interference waves and there is no fading, it is determined that the conditions for calibration measurement are satisfied, and the calibration measurement request is issued. Is transmitted to the base station side. The calibration measurement request is a measurement time (average time of DU ratio described later),
Includes calibration conditions such as signal frequency used. This calibration measurement request is transmitted from the terminal to the base station via the control channel CCH.

On the side of the base station that has received this calibration measurement request, it is determined in step S3 whether or not the measurement conditions for calibration are satisfied. The measurement conditions here include conditions related to the radio environment such as low interference waves around the base station and no fading, as well as conditions related to whether or not the base station itself is suitable for calibration. Including. That is, whether or not the base station is in communication with another terminal in the time slot used for calibration.

In step S3, when the base station determines that the measurement conditions for calibration are satisfied, it sends a calibration measurement instruction to the terminal side. This calibration measurement instruction is transmitted from the base station to the terminal via the control channel CCH.

After that, the control channel CCH is switched to the communication channel TCH, and during the data communication, as shown in FIGS.
The calibration processing of the transmission directivity of the adaptive array terminal is executed according to the principle shown in FIG.

First, a signal for calibration is transmitted from the adaptive array base station 2 side to the adaptive array terminal 3 (step S4). More specifically, as shown in FIG. 2, antennas 21 and 22 of adaptive array base station 2 transmit desired signals and antennas 23 and 24 transmit interference signals.

On the adaptive array terminal 3 side, these calibration signals are received by the array (step S5). More specifically, the adaptive array terminal 3
Receives the signal from the base station 2 in the reception directivity pattern as shown in FIG. 2 by the adaptive array processing.

On the terminal 3 side, the reception weight formed for receiving the desired signal is multiplied by a certain correction value to obtain the transmission weight, and the transmission directivity pattern as shown in FIG. 3 is formed, that is, the base station. With the beam directed to the two antennas 21 and 22 and the null to the antennas 23 and 24,
A signal is transmitted (step S5). Here, as the initial value of the correction value, for example, an existing correction value determined at the time of the previous calibration is used.

On the base station 2 side, the reception response vector (D wave) of the signal from the terminal 3 received by the antennas 21 and 22 as described above is received by the antennas 23 and 24. The DU ratio of the received signal power between the antennas is measured based on the received response vector (U wave) of the signal from the terminal 3 (step S4). Then, the measurement result is stored in the memory on the base station 2 side.

D by such steps S4 and S5
The U ratio measurement operation is repeatedly executed for a predetermined time (time specified by the terminal by the calibration measurement request) during the data communication of the communication channel.

When a predetermined time has passed, the average value of the DU ratios measured on the base station side within that time is calculated on the base station side, and the result is notified to the terminal side (step S
6). This DU ratio measurement result is transmitted from the base station to the terminal via the communication channel TCH.

The adaptive array terminal 3 side receives this DU ratio measurement result and determines whether or not it is equal to or greater than a predetermined value (step S7). As described with reference to FIG. 3, the better the transmission directivity of the terminal 3, the deeper the null in the transmission directivity pattern shape (the smaller the interference component), and the DU ratio measured on the base station side is growing.

If the measured average DU ratio is equal to or larger than the predetermined value, the terminal 3 determines that the reception weight has already been corrected by the appropriate correction value in step S5 described above, and sets the correction value to the final value. Determine and record the calibration correction value. Then, the calibration end notification is transmitted to the base station 2 side (step S7).

Then, the terminal 3 forms a transmission weight by multiplying the reception weight by the correction value until the next calibration is executed. Thereby, the optimum transmission directivity is formed.

On the other hand, when the terminal determines that the measured average DU ratio is not more than the predetermined value, it determines to change the correction value and continue the calibration process, and sends the calibration continuation request to the base station. It is transmitted to the station side (step S7).

Subsequent operations are the same as steps S3 to S described above.
It is a repetition of the operation up to 7, confirming the calibration measurement conditions again on the base station side, if the conditions are satisfied, send the calibration measurement instruction to the terminal side, and measure the DU ratio described above during data communication. Repeat.

Thus, the average D obtained on the base station 2 side
The calibration process (measurement of the average DU ratio) is continued while updating the correction value by which the reception weight is multiplied on the terminal side 3 until the U ratio becomes equal to or higher than a predetermined value. Finally, the correction value when the average DU ratio becomes equal to or higher than the predetermined value is determined as the calibration correction value.

In the above method, the average value of the DU ratios measured within the predetermined time is measured on the base station side and sent back to the terminal side. However, the calibration method based on the DU ratio according to the first embodiment is used. Is not limited to this method.

For example, in steps S4 and 5 of FIG. 4, the DU ratio measured on the base station side is returned from the base station each time the correction value is changed on the terminal side, and the optimum DU ratio is returned in the process of steps S4 and S5. You may make it determine the correction value with which the (maximum) DU ratio was obtained.

The base station side may transmit the calculated reception response vector (D wave and U wave) to the terminal side, and the terminal side may calculate the DU ratio.

Next, FIG. 5 is a block diagram showing the configuration of the adaptive array terminal 3 which is the target of the transmission directivity calibration according to the embodiment shown in FIGS.

The configuration of the adaptive array terminal 3 to be calibrated will be described in detail with reference to FIG. The adaptive array terminal 3 of FIG. 5 includes an array antenna including a plurality of antennas, for example, antennas 31 and 32. The antennas 31 and 32 are connected to the wireless units 310 and 320, respectively. Radio section 3
10 and 320 have exactly the same configuration.

The radio section 310 includes a switch 315, a transmitting section 311, a receiving section 312, a D / A converter 313,
And an A / D converter 314.

At the time of reception, the switch 315 is switched so that the signal received by the antenna 31 is given to the receiving section 312. The receiving unit 312 includes a low noise amplifier and the like, and performs various analog signal processing such as frequency conversion from a high frequency to a low frequency, amplification, etc., on an applied reception signal to perform A / A conversion.
It is supplied to the D converter 314. The received signal given to the A / D converter 314 is converted into a digital signal and given to the user signal processing section 50.

On the other hand, the radio section 320 has a switch 325.
, Transmission unit 321, reception unit 322, and D / A converter 3
23 and an A / D converter 324.

At the time of reception, the switch 325 is switched so that the signal received by the antenna 32 is given to the receiving section 322. The reception unit 322 includes a low noise amplifier and the like, and performs various analog signal processing such as frequency conversion from high frequency to low frequency and amplification on a given reception signal to perform A / A conversion.
It is supplied to the D converter 324. The received signal given to the A / D converter 324 is converted into a digital signal and given to the user signal processing section 50.

The user signal processing unit 50, under the control of the control unit 70 which will be described later, executes the processing relating to the formation of the directivity pattern of the reception and transmission of the terminal 3. That is, the user signal processing unit 50 extracts the user signal from the base station communicating with the terminal 3 by the adaptive array processing described later. The extracted user signal from the base station is
The signal is given to the modem unit 60, subjected to predetermined processing including π / 4 shift QPSK demodulation, restored to the original signal, and supplied to an audio reproducing device such as a speaker (not shown).

On the other hand, at the time of transmission, the transmission signal given from an audio signal source such as a microphone (not shown) is transmitted to the modem section 60.
Predetermined processing including π / 4 shift QPSK modulation is performed via the, and provided to the user signal processing unit 50.

As will be described later, the user signal processing section 50 weights the transmission signal input from the modem section 60 so that it can be transmitted to a desired terminal (forming a transmission directivity), and then the radio section 310 has a transmission signal. It is given to the D / A converter 313 and the D / A converter 323 of the wireless section 320.

The transmission signal converted into an analog signal by the D / A converter 313 of the radio section 310 is given to the transmission section 311 including a high power amplifier and the like, where the frequency conversion from low frequency to high frequency and transmission output are performed. Amplification up to the level,
Various analog signal processing required for wireless transmission is performed.
The transmission output is adjusted by controlling the gain of the high power amplifier according to the instruction from the control unit 70.

At the time of transmission, the switch 315 switches the transmission unit 3
11 is switched to connect the antenna 31 and the transmission signal radio-processed by the transmission unit 311 is transmitted from the antenna 31.

On the other hand, the D / A converter 323 of the radio section 320
The transmission signal converted into the analog signal by is given to the transmission unit 321 including a high-power amplifier and the like, where various kinds of signals required for wireless transmission such as frequency conversion from low frequency to high frequency and amplification up to the transmission output level are provided. Analog signal processing is performed. The transmission output is adjusted by controlling the gain of the high power amplifier according to the instruction from the control unit 70.

At the time of transmission, the switch 325 switches the transmission unit 3
The transmission signal switched to connect the antenna 21 and the antenna 32 and wirelessly processed by the transmitter 321 is transmitted from the antenna 32.

At the time of calibration of the transmission directivity, the control unit 70 executes the calibration process according to the information from the other party's adaptive array base station 2 contained in the received signal demodulated by the modem unit 60. , And controls the user signal processing unit 50. Control unit 70
Is composed of a central processing unit (CPU), a memory and the like.

The user signal processing section 50 is realized by software using a digital signal processor (DSP).

FIG. 6 shows the user signal processing section 5 shown in FIG.
It is a functional block diagram which shows the structure of 0. Referring to FIG. 6, a digital reception signal given from receiving section 312 of radio section 310 corresponding to antenna 31 of FIG. 5 via A / D converter 314 and reception of radio section 320 corresponding to antenna 32. The digital received signal provided from the unit 322 via the A / D converter 324 is converted into the user signal processing unit 50.
Given to.

The processing of these digital signals supplied to the user signal processing section 50 will be described below. These signals supplied to the user signal processing unit 50 are adaptively software-processed by a DSP (not shown) of the adaptive array terminal according to the functional block diagram shown in FIG.

Referring to FIG. 6, received signal vectors x1 (t) and x2, which are two systems of digital received signals provided from radio sections 310 and 320 to user signal processing section 50.
(T) is given to one input of each of the multipliers MR1 and MR2, and the reception weight vector calculator 5
Given to 2.

The reception weight vector calculator 52 uses the well-known adaptive array algorithm rhythm to calculate the weight vectors w ₁ and w ₂ consisting of weights for each antenna.
Is calculated and given to the other input of each of the multipliers MR1 and MR2 to perform complex multiplication with the received signal vector from the corresponding antenna. The adder AD1 obtains a received signal, which is the sum of the complex multiplication results, and supplies the received signal to the modem section 60 in FIG.

On the other hand, the transmission weight vector calculator 54
Outputs a weight vector obtained by correcting the reception weight vectors w ₁ and w ₂ from the reception weight vector calculator 52 by the correction value multiplication circuit 55 as a transmission weight vector.

The transmission signal from the modem unit 60 of FIG. 5 is given to one input terminal of each of the multipliers MT1 and MT2, and the transmission weight vector calculator 54 applies to the other input terminal of each of the multipliers MT1 and MT2. The obtained transmission weight vector is applied.

As described above, the digital transmission signals weighted by the complex multiplication with the transmission weight vector in the user signal processing unit 50 are given to the radio units 310 and 320, respectively. The digital transmission signals given to the radio units 310 and 320 are transmitted via the antennas 31 and 32, respectively.

Next, the calculation of the reception weight vector by the reception weight vector calculator 52 will be described. Here, for example, there are two base stations, that is, a desired base station and an interfering base station, of which a signal from the desired base station is a desired signal and a signal from the interfering base station is an interfering signal.

First, the signal from the desired base station is set to A (t),
If the signal from the interfering base station is B (t), the received signal x1 (t) at the antenna 31 of FIG. 5 is expressed by the following equation: x1 (t) = a1 × A (t) + b1 × B (t) Here, a1 and b1 are coefficients that change in real time.

Next, the received signal x2 at the antenna 32 is
(T) is expressed by the following equation: x2 (t) = a2 * A (t) + b2 * B (t) where a2 and b2 are also coefficients that change in real time.

The above-mentioned coefficients a1 and a2 represent the phase and amplitude information of the reception signals of the antennas 31 and 32 with respect to the signal radio wave from the desired base station, and the coefficients b1 and b2.
For the signal radio wave from the interfering base station, the antenna 31,
It represents the phase and amplitude information of each of the 32 received signals. Since the terminal is moving, these coefficients change in real time.

Signal x1 received by each antenna
(T) and x2 (t) are given to one inputs of the multipliers MR1 and MR2, respectively, which form an adaptive array,
To the other inputs of these multipliers, weight vectors w ₁ and w _{2 which} are calculated in real time by the reception weight vector calculator 52 and are composed of weights for the reception signals at the respective antennas are applied.

Therefore, the output of the multiplier MR1 is w ₁
X (a1A (t) + b1B (t)), and the multiplier MR
The output of 2 is w ₂ × (a2A (t) + b2B (t)).

The outputs of these multipliers MR1 and MR2 are
Addition is performed by the adder AD1, and the output is as follows: w₁(A1A (t) + b1B (t)) + w₂(A2A
(T) + b2B (t)) This is related to the signal A (t) term and the signal B (t)
Divided into terms and terms: (W₁a1 + w₂a2) A (t) + (w₁b1 + w₂b2)
B (t) Here, the reception weight vector calculator 52 is
Identify the station and interfering base station, and
The above weight w so that only the signal can be extracted ₁, W₂To
calculate. For example, the reception wave of the user signal processing unit 50.
Byte vector calculator 52 receives signal A from the desired base station.
To extract only (t), the coefficients a1, a2, b1,
b2 is regarded as a constant, and the coefficient of the signal A (t) as a whole
1, so that the coefficient of the signal B (t) becomes 0 as a whole,
Weight w₁, W₂To calculate.

By setting the weights w ₁ and w ₂ in this way, the output signal of the adder AD1 becomes as follows.

Output signal = 1 × A (t) + 0 × B (t) = A (t) As described above, the coefficient for the desired signal A (t) from the base station that is the desired signal source is 1, and the interference signal is The beam is directed to the base station which is the desired signal source by obtaining the reception weights w ₁ and w ₂ such that the coefficient for the interference signal B (t) from the base station which is the source becomes 0 and using them as the transmission weights. , A transmission directivity in which null is directed to the base station which is the interference signal source is formed.

In the above-mentioned adaptive array terminal 3 shown in FIGS. 5 and 6, how the transmission directivity calibration processing according to the embodiment of the present invention is performed will be described below.

The antennas 21 and 22 of the adaptive array base station 2 shown in FIG. 2 correspond to the above-mentioned desired signal source (desired base station), and the antennas 23 and 24 correspond to the interference signal source (interference base station).

Then, the reception weight vector calculator 52 of the user signal processing unit 50 (FIG. 6) of the adaptive array terminal 3 to be calibrated responds to the signal A (t) from the desired signal source (antennas 21 and 22). The reception weights w ₁ and w ₂ are obtained such that the coefficient is 1 and the coefficient for the signal B (t) from the interference signal source (antennas 23 and 24) is 0, and used as transmission weights.

As a result, as shown in FIG. 3, a transmission directivity pattern in which the beam is directed to the desired signal source (antennas 21 and 22) and the null is directed to the interference signal sources (antennas 23 and 24) is formed. .

However, the reception weights w ₁ and w ₂ are multiplied by the correction value by the correction value multiplication circuit 55. As described with reference to FIG. 4, the adaptive array base station 2 transmits the measured DU ratio information to the terminal 3.

This DU ratio information is used for the modem section 60 of the terminal 3.
It is reproduced by and is given to the control unit 70. The control unit 70
By the procedure described in FIG. 4, the correction values to be multiplied by the reception weights w ₁ and w ₂ are updated until it is determined that the DU ratio sent from the adaptive array base station 2 is equal to or greater than a predetermined value. The correction value multiplication circuit 55 is controlled.

On the other hand, FIG. 7 shows the configuration of the adaptive array base station 2 having at least four antennas.

The configuration of adaptive array base station 2 for performing calibration will be described in detail with reference to FIG. Adaptive array base station 2 of FIG.
Is at least four antennas, for example antenna 2
An array antenna composed of 1, 22, 23 and 24 is provided. The antennas 21, 22, 23 and 24 are respectively
It is connected to the radio units 210, 220, 230, 240.
Since the radio units 210, 220, 230 and 240 have exactly the same configuration, only the configuration and operation of the radio unit 210 will be described.

The radio section 210 includes a switch 215, a transmission section 211, a reception section 212, a D / A converter 213,
And an A / D converter 214.

At the time of reception, the switch 215 is switched so that the signal received by the antenna 21 is given to the receiving section 212. The receiving unit 212 includes a low noise amplifier and the like, and performs various analog signal processing such as frequency conversion from a high frequency to a low frequency, amplification, etc. on a given received signal to perform A / A conversion.
It is given to the D converter 214. The reception signal given to the A / D converter 214 is converted into a digital signal and given to the user signal processing section 80.

The received signals converted into digital signals from the radio units 220, 230, 240 are also used by the user signal processing unit 80.
Given to.

The user signal processing section 80 operates when the adaptive array base station 2 is communicating with one terminal 1 as shown in FIG. 1 and when this adaptive array base station 2 is in communication with this terminal 1 as shown in FIGS.
The operation is different from when the calibration of the adaptive array terminal 3 is performed while maintaining the connection with. These operations will be described later.

The user signal processing section 80 normally separates and extracts the received signal from the terminal connected to the adaptive array base station 2 by the adaptive array processing. The received signal from the separated and extracted terminal is the modem unit 9
The signal is given to 0, subjected to predetermined processing including π / 4 shift QPSK demodulation, restored to the original signal and supplied to a public line network (not shown).

On the other hand, at the time of transmission, a transmission signal given from a public line network (not shown) is transmitted via the modem section 90 by π /
Predetermined processing including 4-shift QPSK modulation is performed and provided to user signal processing section 80.

The user signal processing section 80 weights the transmission signal input from the modem section 90 so that it can be transmitted to a desired terminal (forming a transmission directivity), and the radio section 210.
D / A converter 213 and radio units 220, 230, 2
40 to a D / A converter (not shown).

The transmission signal converted into an analog signal by the D / A converter 213 of the radio section 210 is applied to the transmission section 211 including a high power amplifier and the like, where the frequency conversion from low frequency to high frequency and transmission output are performed. Amplification up to the level,
Various analog signal processing required for wireless transmission is performed.
The transmission output is adjusted by controlling the gain of the high power amplifier according to an instruction from a control unit (not shown).

At the time of transmission, the switch 215 has the transmitting unit 2
The transmission signal switched to connect 11 and the antenna 21 and wirelessly processed by the transmission unit 211 is transmitted from the antenna 31.

Similar processing is performed also in radio sections 220, 230 and 240, and the radio-processed transmission signals are transmitted from antennas 22, 23 and 24.

Next, how the transmission directivity calibration process according to the embodiment of the present invention is performed using adaptive array base station 2 shown in FIG. 7 will be described.

FIG. 8 is a block diagram of the user signal processing unit 80 when the adaptive array base station 2 communicates with one terminal 1 using four antennas as shown in FIG.
It is a functional block diagram which explains processing of SP functionally,
9 and 10 show the configuration of the user signal processing unit 80 when the adaptive array terminal 3 is calibrated while maintaining the connection with the terminal 1 by dividing the antennas as shown in FIGS. 2 and 3. DSP
3 is a functional block diagram functionally explaining the processing of FIG. These block diagrams are realized by combining the DSP with various circuit elements in order to explain the principle of operation realized by the DSP, and actually follow the flow chart of FIG. 4 and FIG. 12 described later. The processing is realized by software.

First, the operation of the user signal processing section 80 when the adaptive array base station 2 communicates with one terminal 1 as shown in FIG. 1 will be described with reference to FIG.

In FIG. 8, from the receiving section 212 of the radio section 210 corresponding to the antenna 21 of FIG. 7 to the A / D converter 21.
Digital received signal given via 4 and radio units 220, 23 corresponding to antennas 22, 23, 24
Digital reception signals given from respective receiving units (not shown) of 0 and 240 via the A / D converter (not shown) are given to the user signal processing unit 80.

The processing of these digital signals supplied to the user signal processing section 80 will be described below. According to the functional block diagram shown in FIG. 8, the DSP (not shown) of the adaptive array base station 2 applies adaptive array processing to these signals provided to the user signal processing unit 80 by software.

Referring to FIG. 8, radio units 210, 220,
Received signal vector x composed of four systems of digital received signals given to the user signal processing unit 80 from 230 and 240
1 (t), x2 (t), x3 (t) and x4 (t) are given to one input of each of the multipliers MR1, MR2, MR3 and MR4 and also given to the reception weight vector calculator 81.

The reception weight vector calculator 81 is shown in FIG.
Weight vectors w ₁ , w ₂ , w ₃ , w ₄ consisting of weights for each antenna are calculated and multiplied by the well-known adaptive array algorithm rhythm already described in relation to the user signal processing unit 50 of the adaptive array terminal 3 of FIG. It is applied to the other input of each of the devices MR1, MR2, MR3, MR4, and each of them is subjected to complex multiplication with the received signal vector from the corresponding antenna. The adder AD1 obtains the received signal, which is the sum of the complex multiplication results, and supplies it to the modem section 90 in FIG.

On the other hand, the transmission weight vector calculator 82
Receives the reception weight vectors w ₁ , w ₂ , w ₃ and w ₄ from the reception weight vector calculator 81 and outputs them as transmission weight vectors.

The transmission signal from the modem section 90 of FIG. 7 is given to one input terminal of each of the multipliers MT1, MT2, MT3, MT4, and the multipliers MT1, MT2, MT3.
The transmission weight vector obtained by the transmission weight vector calculator 82 is applied to the other input terminal of each MT4.

As described above, the digital transmission signals weighted by the complex multiplication with the transmission weight vector by the user signal processing unit 80 are transmitted to the radio units 210, 220, 230, respectively.
Given to 240. Radio units 210, 220, 230,
The digital transmission signals given to 240 are transmitted via antennas 21, 22, 23 and 24, respectively.

As a result, a signal is transmitted from the adaptive array base station 2 in a form in which the beam is directed to the antenna 11 of the terminal 1 in the transmission directivity pattern shown in FIG.

On the other hand, as shown in FIGS. 2 and 3, the user signal processing unit 80 of the adaptive array base station 2 in the case of executing the calibration of the adaptive array terminal 3 while maintaining the connection with the terminal 1. The operation of will be described.

In this case, the user signal processing section 80 has the function shown in FIG.
The function of the processing unit 80a for the terminal 1 shown in FIG. 10 and the function of the processing unit 80b for the terminal 3 shown in FIG. 10 are realized in parallel. That is, as described above with reference to FIGS. 2 and 3, in this case four antennas 21, 22, 2
3, 24 are divided into two groups, the antennas 21 and 22 are used for calibration of the terminal 3, and the antennas 23,
24 is used to maintain communication with the terminal 1.

First, referring to FIG. 9, the antennas 23, 2
Processing unit 80 of the adaptive array base station 2 using
The process of forming the directivity for the terminal 1 by a will be described.

Referring to FIG. 9, a receiver (not shown) of radio section 230 corresponding to antenna 23 receives an A / D signal (not shown).
The digital reception signal provided via the converter and the digital reception signal provided via the A / D converter (not shown) from the reception unit (not shown) of the radio unit 240 corresponding to the antenna 24 are converted into the user signal processing unit 80a. Given to.

The processing of these digital signals supplied to the user signal processing section 80a will be described below. These signals provided to the user signal processing unit 80a are software-processed by the DSP (not shown) of the adaptive array base station 2 according to the functional block diagram shown in FIG.

Referring to FIG. 9, a received signal vector x1 from the terminal 1 consisting of two systems of digital received signals given from the radio units 230 and 240 to the user signal processing unit 80a.
(T) and x2 (t) are provided to one input of each of the multipliers MR1 and MR2, and are also provided to the reception weight vector calculator 87 and the reception response vector estimation unit 88.

The reception weight vector calculator 87 calculates weight vectors w ₁ and w ₂ consisting of weights for each antenna according to the well-known adaptive array algorithm rhythm described above, and gives the weight vectors w ₁ and w ₂ to the other inputs of the multipliers MR1 and MR2. Then, the received signal vector from the corresponding antenna is subjected to complex multiplication. The adder AD1 obtains the received signal which is the sum of the complex multiplication results,
It is given to the modem unit 90 of FIG.

On the other hand, the reception response vector estimation unit 88 extracts the reception signal vectors x1 (t) and x2 (t) and the processing unit 80b (FIG. 10) described later, and the modem unit 90 of FIG.
A reception response vector of the signal of the terminal 3 is calculated by the method described later based on the signal of the terminal 3 demodulated in step 1 and given to the DU ratio measuring unit 100 in FIG.

The transmission signal from the modem section 90 of FIG. 7 is applied to one input terminal of each of the multipliers MT1 and MT2, and the reception weight vector is transmitted to the other input terminal of each of the multipliers MT1 and MT2. It is applied as a vector from the transmission weight vector calculator 89.

As described above, the digital transmission signals weighted by the complex multiplication with the transmission weight vector in the user signal processing unit 80a are given to the radio units 230 and 240, respectively. The digital transmission signals provided to the radio units 230 and 240 are transmitted via the antennas 23 and 24, respectively.

Next, the estimation of the reception response vector by the reception response vector estimating section 88 will be described. First, the basic concept of calculating the reception response vector will be described.

Received signal x1 at antennas 23 and 24
When (t) and x2 (t) are represented by the above equations, the reception response vector Ha from the terminal 3 is represented by the following equation: Ha = [a1, a2] ^T (T is a transpose) where: 3 signal A (t) and terminal 1 signal B (t)
It is assumed that there is no correlation with. Further, it is assumed that the signal A (t) of the terminal 3 is generated as the reference signal.

The reception response vector estimator 88 multiplies the received signal x1 (t) by the reference signal A * (t) (* is a complex conjugate) and takes the ensemble average to calculate a1 based on the following equation. : E [x1 (t) A * (t)] = E [a1A (t) A * (t)] + E [b1B (t) A
* (T)] ≈a1 Here, the ensemble average between the same signals is 1, and the ensemble average between uncorrelated signals is almost 0.
E [A (t) A * (t)] = 1, E [B (t) A *
(T)] ≈0.

Then, a2 is calculated by performing the same calculation on the received signal x2 (t): E [x2 (t) A * (t)] = E [a2A (t) A * (t )] + E [b2B (t) A
* (T)] ≈a2 From the above, the reception response vector of the terminal 3 can be calculated. The reception response vector of the terminal 3 is given to the DU ratio measuring unit 100 of FIG. 7, as described above.

On the other hand, as shown in FIG. 2, from antennas 21 and 22 of adaptive array base station 2, a desired signal for terminal 3 is transmitted with a transmission directivity in which null is forcibly directed to terminal 1. It Further, as shown in FIG. 3, the antennas 21 and 22 of the adaptive array base station 2 are
A signal is transmitted from the terminal 3 in a transmission directivity pattern in which a beam is directed.

Next, referring to FIG. 10, the antennas 21,
Processing unit 8 of adaptive array base station 2 using 22
A process of forming directivity for the terminal 3 by 0b will be described.

Referring to FIG. 10, from receiving section 212 of radio section 210 corresponding to antenna 21 to A / D converter 214.
The digital received signal given via the digital received signal given via the A / D converter (not shown) from the not-shown receiving section of the radio section 220 corresponding to the antenna 22 is given to the user signal processing section 80b. To be

The processing of these digital signals supplied to the user signal processing section 80b will be described below. These signals supplied to the user signal processing unit 80b are software-processed by the DSP (not shown) of the adaptive array base station 2 according to the functional block diagram shown in FIG.

Referring to FIG. 10, radio units 210 and 220
A received signal vector x from the terminal 3 consisting of two systems of digital received signals given to the user signal processing unit 80b from
1 (t) and x2 (t) are given to one input of each of the multipliers MR1 and MR2, and are given to the reception weight vector calculator 83 and the reception response vector estimation unit 84.

The reception weight vector calculator 84 calculates weight vectors w ₁ and w ₂ consisting of weights for each antenna according to the well-known adaptive array algorithm rhythm described above, and gives the weight vectors w ₁ and w ₂ to the other inputs of the multipliers MR1 and MR2. Then, the received signal vector from the corresponding antenna is subjected to complex multiplication. The adder AD1 obtains the received signal which is the sum of the complex multiplication results,
It is given to the modem unit 90 of FIG.

On the other hand, the reception response vector estimation unit 84 receives the reception signal vectors x1 (t) and x2 (t) and the processing unit 80.
a and 80b respectively, and the modem unit 9 of FIG.
Based on the signals of the terminals 1 and 3 demodulated by 0, the reception response vector of the signals of the terminals 1 and 3 is calculated by the above-described method, and is given to the forced null weight estimation unit 85. The calculated reception response vector of the signal of the terminal 3 is also shown in FIG.
Of the DU ratio measuring unit 100.

Forced null weight estimation section 85 estimates a forced null weight vector for directing null to terminal 1 by a method described later, based on the received reception response vectors of the signals of terminals 1 and 3, and transmits the transmission weight vector. It is given to the computer 86.

The transmission signal from the modem section 90 of FIG. 7 is given to one input terminal of each of the multipliers MT1 and MT2, and the transmission weight vector calculator 86 from the other input terminal of each of the multipliers MT1 and MT2. , The forced null weight vector is applied as the transmit weight vector.

As described above, the digital transmission signals weighted by the complex multiplication with the transmission weight vector in the user signal processing unit 80b are given to the radio units 210 and 220, respectively. The digital transmission signals given to the radio units 210 and 220 are transmitted via the antennas 21 and 22, respectively.

The forced null weight estimation unit 85 receives the reception response vectors of the terminals 1 and 3 from the reception response vector estimation unit 84 and calculates a weight vector (hereinafter, forced null weight vector) such that null is oriented to the terminal 1. . The basic idea of the calculation of the forced null weight vector will be described below.

As described above, when the output signal of the adaptive array is divided into the term relating to the signal A (t) of the terminal 3 and the term relating to the signal B (t) of the terminal 1, it can be expressed as follows: (W ₁ a1 + w ₂ a2) A (t) + (w ₁ b1 + w ₂ b2)
B (t) At this time, in order to suppress the signal B (t) from the terminal 1, the coefficient of the signal B (t) becomes 0 as a whole, and the signal A (t) is
The weight w ₁ , so that the coefficient of (t) is 1 as a whole.
calculate the w _2: by _{w 1 b1 + w 2 b2 =} 0 w 1 a1 + w 2 a2 = 1 reception weight vector calculator 83, b1, b2
Since k is already known, w ₁ and w ₂ can be calculated directly by the above equation. The weight calculated in this way is called a forced null weight.

At the time of calibrating the transmission directivity of the terminal 3, in the base station 2, the transmission signal is input from the modem section 90 to one input of each of the multipliers MT1 and MT2 forming the adaptive array, and these multipliers The forced null weight vector calculated by the forced null weight estimation unit 85 is input to the other input.

As a result, as shown in FIGS. 2 and 3, adaptive array base station 2 is capable of exchanging signals with terminal 3 in a reception and transmission directivity in which null is directed to terminal 1.

The reception response vector of the signal from the terminal 3 received by the antennas 23 and 24 is given from the reception response vector estimating section 88 of the processing section 80a to the DU ratio measuring section 100, and the terminal 3 received by the antennas 21 and 22. The reception response vector of the signal from is supplied to the DU ratio measurement unit 100 from the reception response vector estimation unit 84 of the processing unit 80b.

The DU ratio measuring section 100 calculates the DU ratio from the reception response vector as follows. That is, the reception response vector (D
Wave) and H _D, the reception response vector of the user terminal 3 received by the antenna 23, 24 (U wave) and H _U, DU ratio is expressed by the following _{equation: DU = 10 · LOG 10 (} | H D | / | H _U |) The DU ratio measuring unit 100 obtains the average value of the DU ratio over a predetermined period as described above, and gives the result to the modem unit 90.

The modem section 90 inserts this DU ratio measurement information into the transmission signal and transmits it to the adaptive array terminal 3. The terminal 3 controls the correction value multiplication circuit 55 (FIG. 6) as described above based on this DU ratio measurement information.

Next, of the transmission directivity calibration method according to the embodiment of the present invention, FIG. 11 is executed by software on the side of the adaptive array terminal 3 to be the calibration target shown in FIGS. 5 and 6. FIG. 12 is a flowchart showing a process to be executed, and FIG. 12 is a flowchart showing a process to be executed on the adaptive array base station 2 side shown in FIGS. 7 to 10.

The calibration process according to the embodiment of the present invention will be described in detail with reference to FIGS. 11 and 12.

First, on the adaptive array terminal 3 side, it is judged whether or not the activation condition for calibration described with reference to FIG. 4 is satisfied (step S101 in FIG. 11). If it is determined that the activation condition is satisfied, the terminal 3 side determines whether or not the calibration measurement condition described with reference to FIG. 4 is satisfied (step S102 in FIG. 11).

If it is determined that the measurement conditions are satisfied, the calibration measurement request is transmitted from the terminal 3 to the base station 2 (step S103 in FIG. 11).

On the side of the base station 2, it is judged whether or not the calibration measurement request from the terminal 3 has been received (FIG. 12).
Step S201) of FIG.
It is determined whether or not the measurement conditions for calibration described in relation to step S1 are satisfied (step S in FIG. 12).
202).

If it is determined that the measurement condition is satisfied, the calibration measurement instruction is transmitted from the base station 2 to the terminal 3 (step S203 in FIG. 12). And
The communication state (normal mode) with the terminal 1 using the antennas 21, 22, 23, and 24 shown in FIG. 1 is changed to the state in which the antennas are divided and used between the terminal 1 and the terminal 3 shown in FIGS. In the base station 2, the mode is switched to a mode for performing calibration by spatial multiplex connection (calibration multiplex mode) (step S204 in FIG. 12).
On the terminal 3 side, it is determined whether or not the calibration measurement instruction from the base station 2 is received before the message reception timer expires (step S105 in FIG. 11) (step S104 in FIG. 11), and until the expiration. If not received, the process returns to step S103 to retransmit the calibration measurement request to the base station 2.

If it is determined that the calibration measurement instruction from the base station 2 is received before the message reception timer expires (step S105 in FIG. 11) (step S104 in FIG. 11), the terminal 3 and the base station 1 to 4, during data communication with the mobile station 2, data transmission by the base station 2 and measurement of the DU ratio of the received signal (step S205 in FIG. 12), and reception weight by the terminal 3 Array transmission / reception (step S106 in FIG. 11) is executed while updating the correction value of.

Such transmission / reception between the terminal 3 and the base station 2 is executed until the calibration measurement timer expires in both the terminal 3 and the base station 2 (FIG. 1).
1 step S107 and FIG. 12 step S20.
6).

On the base station 2 side, the average value of the DU ratios measured during the period until the calibration measurement timer expires is calculated and transmitted to the terminal 3 (step S207 in FIG. 12).

On the side of the terminal 3, it is judged whether or not the measurement result (average value) of the DU ratio is received from the base station 2 (step S108 in FIG. 11), and if it is judged that it is received, the DU ratio is judged. Is recorded and determined (step S109 in FIG. 11).

Then, it is determined whether or not the received measurement result of the DU has reached the predetermined DU ratio (step S110 in FIG. 11). If it is determined that it has not reached, the calibration measurement request of step S103 is made. Returning to step S106, the correction value of the reception weight is updated during the array transmission / reception in step S106, and the base station 2 measures the DU ratio again.

Thus measured D at terminal 3
Until it is determined that the U ratio has reached the predetermined DU ratio (see FIG. 11).
Step S110), the calibration process by the terminal 3 and the base station 2 is continued.

When it is determined that the measured DU ratio has reached the predetermined DU ratio (step S110 in FIG. 11), the terminal 3
A calibration end notification is transmitted from the base station 2 to the base station 2 (step S111 in FIG. 11), and the existing calibration correction value is updated (rewritten) with the correction value changed at the time of array transmission / reception in step S106 (FIG. 11). Step S112). Then, the terminal 1 ends the process.

On the base station 2 side, the calibration process is executed until it is determined that the calibration end notification is received, and when it is determined that the calibration end notification is received (step S20 in FIG. 12).
8), the base station 2 ends the process.

Then, the divided use of the antennas is stopped, and the communication state (normal mode) with the terminal 1 using the antennas 21, 22, 23 and 24 as shown in FIG. 1 is restored (FIG. 1).
2 step S209).

As described above, according to the embodiment of the present invention, the adaptive array base station 2 having at least four antennas sends the desired signal and the interference signal to the adaptive array terminal 3 to be calibrated, and the adaptive signal is transmitted. All the array antennas of the array terminal 3 are configured to receive these signals in an array at once.

Therefore, in the adaptive array terminal 3 to be calibrated, it is not necessary to repeat the calibration while changing the combination of the antennas, the time required for the calibration can be remarkably shortened, and the reception by all the antennas is possible. Therefore, the reception performance is improved and the calibration accuracy can be improved.

Further, since the signal for calibration is received from the adaptive array base station 2 which is located at a position distant from the terminal 3 to be calibrated, the power control of the transmission / reception signal is simplified and the adaptive signal is adaptive. The resolution of the transmission directivity pattern for the array base station 2 can be improved.

Furthermore, according to this embodiment, even if the base station 2 is communicating with the terminal 1, the calibration of the other terminals 3 can be executed in parallel in the same time slot. You can

The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

[0198]

As described above, according to the present invention, a signal for calibration is sent from the adaptive array base station to the adaptive array terminal to be calibrated and the array antenna of the adaptive array terminal to be calibrated is sent. All of the antennas are configured to receive these signals at once in an array.

Therefore, the time required for the calibration can be remarkably shortened, the power control of the transmission / reception signal can be simplified, and the accuracy of the calibration can be improved.

Furthermore, according to the present invention, even when the adaptive array base station is already communicating with the terminal, the adaptive array base station performs the spatial multiplex connection with another adaptive array terminal in the same time slot, so that the parallel array connection is performed in parallel. Then, the calibration of the other adaptive array terminal can be executed.

[Brief description of drawings]

FIG. 1 is a conceptual diagram schematically showing a first stage of a calibration method according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram schematically showing a second stage of the calibration method according to the embodiment of the present invention.

FIG. 3 is a conceptual diagram schematically showing a third stage of the calibration method according to the embodiment of the present invention.

FIG. 4 is a timing chart showing the procedure of the calibration method according to the embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of an adaptive array terminal to be a calibration target according to the embodiment of the present invention.

6 is a functional block diagram showing a configuration of a user signal processing section 50 shown in FIG.

FIG. 7 is a block diagram showing a configuration of an adaptive array base station which performs calibration according to the embodiment of the present invention.

8 is a functional block diagram illustrating an operation of a user signal processing section 80 shown in FIG. 7 in a normal mode.

9 is a functional block diagram illustrating the operation of the user signal processing unit 80 shown in FIG. 7 in the calibration multiplex mode.

10 is a functional block diagram for explaining the operation of the user signal processing section 80 shown in FIG. 7 in the calibration multiplex mode.

FIG. 11 is a flowchart showing the operation of the adaptive array terminal to be the target of calibration according to the embodiment of the present invention.

FIG. 12 is a flowchart showing an operation of the adaptive array base station which performs calibration according to the embodiment of the present invention.

[Explanation of symbols]

1 1 antenna 2 adaptive array base station 3
Adaptive array terminals 11, 12, 22, 23,
24, 31, 32 antennas, 50, 80 user signal processing unit, 60, 90 modem unit, 70 control unit, 100
DU ratio measuring unit, 210, 220, 230, 240, 3
10,320 radio section.

Claims (17)

[Claims] 1. A radio base station for performing communication with a radio terminal device by adaptive array processing using a first plurality of antennas, wherein at least a part of the first plurality of antennas is used in a normal mode. Means for communicating with an arbitrary wireless terminal device and a calibration multiplex mode for calibrating a specific wireless terminal device that communicates with a wireless base device by adaptive array processing using the second plurality of antennas. Means for dividing the first plurality of antennas into a third plurality of antennas and a fourth plurality of antennas, and continuing communication with the arbitrary wireless terminal device using the third plurality of antennas. Means for forming a transmission directivity for directing null to the arbitrary wireless terminal device by using the fourth plurality of antennas; In the transmission directivity, the same frequency and time slot used for communication with the arbitrary wireless terminal device, means for transmitting a desired signal to the specific wireless terminal device, and the specific wireless terminal device from the A unit for generating information about reception levels of a signal received by a third plurality of antennas and a signal received by the fourth plurality of antennas, and for calibration of transmission directivity in the specific wireless terminal device. A means for transmitting the generated information on the reception level to the specific wireless terminal device. 2. The unit according to claim 1, further comprising a unit for continuing the transmission of the desired signal and the transmission of the information regarding the reception level until the end of calibration is instructed by the specific wireless terminal device. Radio base unit. 3. The means for generating information about the reception level includes a reception response vector of a signal from the specific wireless terminal device received by the third plurality of antennas, and reception by the fourth plurality of antennas. Means for calculating a reception response vector of a signal from the specific wireless terminal device, and the third unit based on the calculated reception response vector.
And a means for calculating a reception level ratio between the plurality of antennas and the fourth plurality of antennas and supplying the calculated reception level ratio as information regarding the reception level. 4. The means for forming the transmission directivity comprises: means for calculating a reception response vector of a signal from the arbitrary wireless terminal device received by the fourth plurality of antennas; and the calculated reception response. The radio base apparatus according to claim 1, further comprising: a unit that calculates a transmission weight forcibly directing null to the arbitrary radio terminal apparatus based on a vector. 5. A transmission directivity calibration method for a wireless terminal device in a wireless base device that communicates with a wireless terminal device by adaptive array processing using a first plurality of antennas, the method comprising: A step of communicating with an arbitrary wireless terminal device using at least a part of one of the plurality of antennas; and a specific wireless terminal device performing communication with a wireless base device by adaptive array processing using the second plurality of antennas. In a calibration multiplex mode in which the first plurality of antennas is divided into a third plurality of antennas and a fourth plurality of antennas, and using the third plurality of antennas, Continuing communication with an arbitrary wireless terminal device; and using the fourth plurality of antennas, Forming a transmission directivity that directs null to the wireless terminal device, and in the formed transmission directivity, at the same frequency and time slot used for communication with the arbitrary wireless terminal device, the specific radio Transmitting a desired signal to the terminal device, and generating information regarding reception levels of a signal received by the third plurality of antennas and a signal received by the fourth plurality of antennas from the specific wireless terminal device. A calibration method, comprising: a step of transmitting information on the generated reception level to the specific wireless terminal apparatus for calibration of transmission directivity in the specific wireless terminal apparatus. 6. The method according to claim 5, further comprising the step of continuing the transmission of the desired signal and the transmission of the information regarding the reception level until the end of calibration is instructed by the specific wireless terminal device. Calibration method. 7. The step of generating information on the reception level includes: a reception response vector of a signal from the specific wireless terminal device received by the third plurality of antennas, and reception by the fourth plurality of antennas. Calculating a reception response vector of a signal from the specific wireless terminal device, and the third receiving unit based on the calculated reception response vector.
And calculating the reception level ratios of the plurality of antennas and the fourth plurality of antennas and supplying the calculated reception level ratios as information regarding the reception level. 8. The step of forming the transmission directivity includes a step of calculating a reception response vector of a signal from the arbitrary wireless terminal device received by the fourth plurality of antennas, and the calculated reception response. And a step of calculating a transmission weight forcibly directing null to the arbitrary wireless terminal device based on a vector. 9. A transmission directivity calibration program for a wireless terminal device in a wireless base device that communicates with a wireless terminal device by adaptive array processing using a first plurality of antennas, the program being executed by a computer in a normal mode. , A step of communicating with an arbitrary wireless terminal apparatus using at least a part of the first plurality of antennas, and a specific step of communicating with a wireless base apparatus by adaptive array processing using the second plurality of antennas. Dividing the first plurality of antennas into a third plurality of antennas and a fourth plurality of antennas in a calibration multiplex mode for calibrating a wireless terminal device; and And continuing communication with the arbitrary wireless terminal device using the fourth plurality of A step of forming a transmission directivity that directs a null to the arbitrary wireless terminal device, using the antenna, in the formed transmission directivity, the same frequency used for communication with the arbitrary wireless terminal device, and Transmitting a desired signal to the specific wireless terminal device in a time slot; a signal received by the third plurality of antennas from the specific wireless terminal device and a signal received by the fourth plurality of antennas And performing a step of transmitting the generated reception level information to the specific wireless terminal device for calibration of transmission directivity in the specific wireless terminal device. Let the calibration program. 10. The method according to claim 9, further comprising the step of continuing the transmission of the desired signal and the transmission of the information about the reception level until the end of calibration is instructed by the specific wireless terminal device. Calibration program. 11. The step of generating information about the reception level includes: a reception response vector of a signal from the specific wireless terminal device received by the third plurality of antennas, and reception by the fourth plurality of antennas. Calculating a reception response vector of a signal from the specific wireless terminal device, and the third receiving unit based on the calculated reception response vector.
10. The calibration program according to claim 9, further comprising: calculating a reception level ratio between the plurality of antennas and the fourth plurality of antennas, and supplying the calculated reception level ratio as information regarding the reception level. 12. The step of forming the transmission directivity includes a step of calculating a reception response vector of a signal from the arbitrary wireless terminal device received by the fourth plurality of antennas, and the calculated reception response. 10. The calibration program according to claim 9, further comprising: calculating a transmission weight forcibly directing null to the arbitrary wireless terminal device based on a vector. 13. A method of calibrating a transmission directivity of a wireless terminal device in a wireless base device for performing communication with a wireless terminal device by adaptive array processing using a first plurality of antennas, the method comprising: A step of communicating with an arbitrary wireless terminal device using at least a part of one of the plurality of antennas; and a specific wireless terminal device performing communication with a wireless base device by adaptive array processing using the second plurality of antennas. In a calibration multiplex mode in which the first plurality of antennas is divided into a third plurality of antennas and a fourth plurality of antennas, and using the third plurality of antennas, Continuing communication with any wireless terminal device, and using the fourth plurality of antennas, A step of forming a transmission directivity that directs null to the wireless terminal device, and the specified transmission directivity at the same frequency and time slot used for communication with the arbitrary wireless terminal device, Transmitting a desired signal to the wireless terminal device by the fourth plurality of antennas, and a desired signal from the fourth plurality of antennas received by the second plurality of antennas in the specific wireless terminal device And weight information for forming a transmission directivity pattern for directing a beam to the fourth plurality of antennas and directing a null to the third plurality of antennas based on signals transmitted from the third plurality of antennas. And a step of correcting the calculated weight information, and a transmission directivity pattern based on the corrected weight information. Transmitting a predetermined signal from the specific wireless terminal device to the wireless base device, the predetermined signal received by the third plurality of antennas from the specific wireless terminal device, and the fourth plurality of signals. A step of generating information about a reception level with the predetermined signal received by the antenna, and for the calibration of the transmission directivity in the specific radio terminal device, the information about the generated reception level is specified. Transmitting to a wireless terminal device, and based on the information on the reception level received by the specific wireless terminal device, determine a correction value of the weight information that optimizes the information on the reception level in the wireless base device. A calibration method comprising steps and. 14. The method according to claim 13, further comprising the step of continuing the transmission of the desired signal and the transmission of the information regarding the reception level until the end of calibration is instructed by the specific wireless terminal device. Calibration method. 15. The step of generating information on the reception level includes: a reception response vector of a signal from the specific wireless terminal device received by the third plurality of antennas, and reception by the fourth plurality of antennas. Calculating a reception response vector of a signal from the specific wireless terminal device, and the third receiving unit based on the calculated reception response vector.
14. The calibration method according to claim 13, further comprising: calculating a reception level ratio of the plurality of antennas and the fourth plurality of antennas, and supplying the calculated reception level ratio as information regarding the reception level. 16. The calibration method according to claim 15, wherein the step of calculating the reception level ratio includes the step of supplying an average of the reception level ratios over a predetermined period as the calculated reception level ratio. . 17. The step of forming the transmission directivity includes a step of calculating a reception response vector of a signal from the arbitrary wireless terminal device received by the fourth plurality of antennas, and the calculated reception response. 14. The calibration method according to claim 13, further comprising: calculating a transmission weight forcibly directing null to the arbitrary wireless terminal device based on a vector.