JP2021190793A - Transmission power control device, radio communications system, transmission power control method, and program - Google Patents

Abstract

To provide a transmission power control device, a radio communications system, a transmission power control method, and a program that can suppress a decrease in communication quality.SOLUTION: A transmission power control device 2 is built in a radio communication system 1 employing a cross-polarization interference compensation system. The transmission power control device 2 comprises a data evaluation part 20 built in a reception station 22, and a transmission-side transmission power controller 15 built in a transmission station 21. The data evaluation part 20 comprises a detector 100 and a controller 102. The detector 100 detects one of a vertical polarization reception signal level V_RSL and a horizontal polarization reception signal level H_RSL which is lower. The controller 102 generates a transmission power control signal DATA1, and generates a status signal DATA2 indicative of an interference state of polarization based upon D/U estimation values that a vertical polarization demodulator 17 and a horizontal polarization demodulator 37 of the reception station 22 calculate.SELECTED DRAWING: Figure 2

Description

The present invention relates to a transmission power control device, a wireless communication system, a transmission power control method, and a program, and more particularly to a wireless communication system, a transmission power control device, a transmission power control method, and a program that employ a cross-polarization interference compensation method.

An example of such a transmission power control device is disclosed in Patent Document 1. The transmission power control device disclosed in Patent Document 1 multiplexes and transmits vertically polarized waves (V polarized waves) and horizontally polarized waves (H polarized waves) of the same frequency, and uses control information obtained from a receiving station. , Control the transmission level of the transmitting station. For example, the receiving station detects the polarized wave having the lower reception level among the two incoming polarized waves, and sends control information to the transmitting station so that the detected level becomes a predetermined level. The transmitting station simultaneously controls the transmission levels of vertically polarized waves and horizontally polarized waves according to this control information. By the way, in the self-polarized wave, the interference wave may leak from the differently polarized wave in the propagation path. By the above-mentioned control, the signal level ratio D / U (Desilable / Undersilable) between the self-polarized wave and the interference wave is made constant. In addition, the resistance to thermal noise can be improved and the communication quality can be maintained.

Japanese Unexamined Patent Publication No. 04-137934

However, in this method, if the signal level ratio D / U deteriorates due to the attenuation of one of the polarizations, the communication quality may deteriorate.

An object of the present disclosure is to provide a transmission power control device, a wireless communication system, a transmission power control method, and a program capable of suppressing deterioration of communication quality in view of the above-mentioned problems.

The transmission power control device according to one of the embodiments of the present disclosure is
In a transmission power control device incorporated in a wireless communication system that employs a cross-polarization interference compensation method,
The wireless communication system includes a transmitting station and a receiving station.
The receiving station includes a vertically polarized wave demodulator and a horizontally polarized wave demodulator.
The transmission power control device includes a data evaluation unit incorporated in the receiving station and a transmitting side transmission power controller incorporated in the transmitting station.
The data evaluation unit includes a detector and a controller.
The detector detects one of the vertically polarized wave received signal level and the horizontally polarized wave received signal level, which has a lower signal level.
The controller generates a transmission power control signal so that one of the detected vertically polarized light received signal level and the horizontally polarized light received signal level is adjusted to a predetermined level, and the vertically polarized demodulator and the above. Based on the D / U estimated value calculated by the horizontal polarization demodulator, a status signal indicating the interference state of polarization is generated.
The transmission power control signal and the status signal are multiplexed and transmitted to the transmission side transmission power controller in a wireless frame.

The wireless communication system according to one of the embodiments of the present disclosure is
In a wireless communication system that employs a cross-polarization interference compensation method,
It has a transmitting station and a receiving station.
The transmitting station includes a transmitting power controller on the transmitting side.
The receiving station includes a data evaluation unit, a vertically polarized wave demodulator, and a horizontally polarized wave demodulator.
The data evaluation unit includes a detector and a controller.
The detector detects one of the vertically polarized wave received signal level and the horizontally polarized wave received signal level, which has a lower signal level.
The controller generates a transmission power control signal so that one of the detected vertically polarized light received signal level and the horizontally polarized light received signal level is adjusted to a predetermined level, and the vertically polarized demodulator and the above. From the D / U estimated value calculated by the horizontal polarization demodulator, a status signal indicating the interference state of polarization is generated.
The transmission power control signal and the status signal are multiplexed and transmitted to the transmission station in a wireless frame.

The transmission power control method according to one of the embodiments of the present disclosure is
In the transmission power control method of a wireless communication system that employs a cross-polarization interference compensation method and has a transmitting station and a receiving station.
The receiving station includes a vertically polarized wave demodulator and a horizontally polarized wave demodulator.
A step of detecting which of the vertically polarized wave received signal level and the horizontally polarized wave received signal level received by the receiving station has a lower signal level, and
A step of generating a transmission power control signal so that one of the detected vertically polarized wave received signal level and horizontally polarized wave received signal level is adjusted to a predetermined level, and
A step of generating a status signal indicating a polarization interference state from the D / U estimated values calculated by the vertically polarized wave demodulator and the horizontally polarized wave demodulator, and
The present invention includes a step of multiplexing the transmission power control signal and the status signal to the transmission station in a wireless frame and transmitting the signal to the transmission station.

The program according to one of the embodiments of the present disclosure is
Operates as a transmission power controller built into a wireless communication system that employs cross-polarization interference compensation,
The wireless communication system includes a transmitting station and a receiving station.
The receiving station is a computer equipped with a vertically polarized wave demodulator and a horizontally polarized wave demodulator.
A step of detecting which of the vertically polarized wave received signal level and the horizontally polarized wave received signal level received by the receiving station has a lower signal level, and
A step of generating a transmission power control signal so that one of the detected vertically polarized wave received signal level and horizontally polarized wave received signal level is adjusted to a predetermined level, and
A step of generating a status signal indicating a polarization interference state from the D / U estimated values calculated by the vertically polarized wave demodulator and the horizontally polarized wave demodulator, and
The step of multiplexing and transmitting the transmission power control signal and the status signal to the transmission station in a wireless frame is executed.

According to the present disclosure, it is possible to provide a transmission power control device, a wireless communication system, a transmission power control method, and a program capable of suppressing deterioration of communication quality.

It is a schematic diagram which shows the wireless communication system which concerns on Embodiment 1. FIG. It is a schematic diagram which shows one operation example of the wireless communication system which concerns on Embodiment 1. FIG. It is a schematic diagram which shows a specific example of the wireless communication system which concerns on Embodiment 1. FIG. It is a block diagram which shows a specific example of a data evaluation part. It is a block diagram which shows a specific example of a transmission side transmission power controller. It is a flowchart which shows the generation method of the transmission power up / down control signal. It is a block diagram which shows a specific example of a V polarization demodulator. It is a block diagram which shows one configuration example of a transmission power controller. It is a figure which shows one configuration example of the hardware included in a wireless communication system. It is a schematic diagram which shows one operation example of the related wireless communication system.

(Embodiment 1)
The wireless communication system according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram showing a wireless communication system according to the first embodiment. FIG. 2 is a schematic diagram showing an operation example of the wireless communication system shown in FIG.

The one-way arrows shown in FIG. 1 and other drawings simply indicate the direction of the flow of a certain signal (data), and do not exclude bidirectionality.

As shown in FIG. 1, the wireless communication system 1 includes a transmitting station 21 and a receiving station 22. The transmitting station 21 includes an antenna 21a. The receiving station 22 includes an antenna 22a. The transmitting station 21 transmits vertically polarized waves (V (Vertical) polarized waves) and horizontally polarized waves (H (Horizontal) polarized waves) from the antenna 21a. The transmitted V-polarized light and H-polarized wave propagate through the radio propagation path 3 and arrive at the antenna 22a. The receiving station 22 receives V-polarized wave and H-polarized wave from the antenna 22a. The transmission spectra of V-polarized wave and H-polarized wave output by the output unit of the antenna 22a of the receiving station 22 are substantially the same, and all are based on their own polarizations.

The transmission spectra of V-polarized wave and H-polarized wave input to the input unit of the antenna 21a of the transmission station 21 are substantially the same. That is, the transmission signal levels of the V-polarized wave and the H-polarized wave at the input portion of the antenna 21a are the same. The V-polarized wave and the H-polarized wave are output from the antenna 21a to the radio propagation path 3, and then interfere with each other in the radio propagation path 3.

The reception spectrum of the V-polarized wave at the output of the antenna 22a has a main wave power D _V, based on the interference signal power U _H. In the V polarization in the output portion of the antenna 22a, the main wave is V polarization and the interference wave is H polarization. Interference signal power U _H is the radio channel 3, based on the leaked from the H-polarized wave to the V-polarized wave component.

The reception spectrum of the H-polarized wave at the output of the antenna 22a has a main wave power D _H, based on the interference signal power U _V. In the H polarization in the output portion of the antenna 22a, the main wave is H polarization and the interference wave is V polarization. Interference signal power U _V, in radio channel 3, based on the leaked from the V-polarized wave to the H-polarized wave component.

When the V-polarized light and the H-polarized light are attenuated by the attenuation amount ATT1 [dB] in the radio propagation path 3, the signal level ratio of the V-polarized light is V_D / U (Desirable / Undesirable) ratio and the H-polarized light is The signal level ratio H_D / U ratio is determined only by the isolation of the antenna 21a of the transmitting station 21 and the antenna 22a of the receiving station 22. Therefore, the signal level ratio V_D / U of V polarization and the signal level ratio H_D / U of H polarization are substantially equal.

Under the environment of the radio propagation path 3, the method disclosed in Patent Document 1 is applied to adjust the transmission level of both polarized waves at the same time. As a result, while maintaining the signal level ratios V_D / U and H_D / U of V-polarized light and H-polarized light, the received signal levels V_RSL and H_RSL of V-polarized light and H-polarized wave are controlled to be equal to or higher than a predetermined level value. It is possible.

(Related technology)
Here, for convenience of explanation of the wireless communication system 1, the wireless communication system 91 shown in FIG. 10 will be described. The wireless communication system 91 relates to a technique related to the wireless communication system 1. FIG. 10 shows an operation example of a wireless communication system in a related technology.

As shown in FIG. 10, the attenuation amount ATT2 [dB] of H polarization may be larger than the attenuation amount ATT1 [dB] of V polarization.

In such a case, the signal level ratio H_D / U of the H polarization shown in FIG. 10 is H shown in FIG. 1 because the H polarization (here, corresponding to the main wave) is attenuated in the radio propagation path 3. The signal level ratio of polarization is smaller than H_D / U. That is, when the H polarization is greatly attenuated as compared with the V polarization, the signal level ratio H_D / U of the H polarization deteriorates.

On the other hand, the signal level ratio V_D / U of V-polarized light shown in FIG. 10 is the signal level ratio V_D / of V-polarized light shown in FIG. 1 because the H polarization (corresponding to the interference wave in this case) is attenuated. Greater than U. That is, when the H polarization is greatly attenuated as compared with the V polarization, the signal level ratio D / U of the V polarization becomes good.

From the above, when the method disclosed in Patent Document 1 is applied in a propagation environment in which one of the polarizations is extremely attenuated as described above, even if the reception level is restored to an appropriate state, the H bias is applied. The wave signal level ratio H_D / U remains degraded. Therefore, the interference state inside the received signal is not improved.

Further, when estimating the signal level ratios V_D / U and H_D / U of V polarization and H polarization, XPIC interference compensation (Cross Polaris (z) ation Interference Cancellation (cross bias), which is a part of the components of the demodulator, is used. There is a method realized by comparing the maximum value of the tap coefficient of the equalizer used for wave interference compensation)) with a threshold value. For example, due to deterioration of the frequency characteristics of the differently polarized interference signal such as the primary gradient and the drop in the amplitude in the characteristic frequency region, the tap coefficient value of the equalizer spreads uniformly, and the peak value at a specific tap can be obtained. May not be. In such a case, in this method, it may be difficult to accurately estimate the signal level ratios V_D / U and H_D / U of V-polarized light and H-polarized wave.

(Embodiment 1)
Returning to FIGS. 1 and 2, the description of the wireless communication system according to the first embodiment is resumed.

In the present embodiment, in addition to the control method of the related technology, first, the signal level ratio D / U estimation result of V-polarized wave and H-polarized wave is confirmed. When deterioration of the signal level ratio D / U is detected based on the signal level ratio D / U estimation result, only the transmission power of one of the polarizations whose signal level ratio D / U has deteriorated is V-polarized light and H. Increase the polarization signal level ratio D / U until they are equivalent (see FIG. 1). As a result, not only the received signal levels V_RSL and H_RSL can be restored to a predetermined level, but also the signal level ratio D / U deterioration of one of the polarized waves can be reduced. Therefore, the deterioration of the transmission quality (signal level ratio D / U) of the one-sided polarized wave (one-sided polarized wave) generated due to the environment of the radio propagation path 3 shown in FIG. 10 is improved.

First, the receiving station 22 refers to the D / U estimated values V_DU and H_DU that estimated the signal level ratio D / U of V-polarized light and H-polarized wave, so that the interference state of V-polarized light and H-polarized wave can be determined. presume. Specifically, when the reception level of one of the polarizations is attenuated and the absolute value of the difference | V_DU-H_DU | is larger than the desired threshold value, the signal level ratio D / U in one of the V polarization and the H polarization Judge that deterioration has occurred. When such deterioration occurs, there is a difference in the signal level ratio D / U of the received signals of both polarized waves. Therefore, the above determination is made using the absolute value | V_DU-H_DU | of the difference. Then, the polarization of the signal level ratio D / U deterioration is estimated from the magnitude relationship between the D / U estimated values V_DU and H_DU. In the example shown in FIG. 10, the polarization of the signal level ratio D / U deterioration is presumed to be H polarization.

Subsequently, based on the above estimation, the transmitting station 21 increases only the transmission power of the polarized light having the deterioration of the signal level ratio D / U so that the D / U estimated values V_DU and H_DU are the same. Let me. As a result, the influence of the signal level ratio D / U deterioration caused by the attenuation of one of the polarizations in the radio propagation path 3 is reduced.

FIG. 2 shows an example of the spectrum after transmission power control. As shown in FIG. 2, due to this transmission power control, the transmission output of the attenuated H-polarized wave in the radio propagation path 3 is increased by an increase amount of ΔH, which is higher than the transmission output of the V-polarized wave. Therefore, since the signal level of H polarization (self-polarization) has increased, the signal level ratio H_D / U has improved. On the other hand, since the level of the interference signal (H polarization) has increased, the signal level ratio D / U of V polarization, which has a smaller attenuation than H polarization, deteriorates. The signal level ratio V_D / U of V polarization is equal to or higher than the D / U level defined by the isolation between the antenna 21a of the transmitting station 21 and the antenna 22a of the receiving station 22, and does not fall below it. The D / U level defined by the isolation of the antenna 21a and the antenna 22a is a value equivalent to the signal level ratio V_D / U of the V-polarized wave shown in FIG. The signal level ratio V_D / U of V polarization has deteriorated. However, this deterioration can be compensated by using the XPIC equalizer inside the demodulation circuit (not shown) in the receiving station 22. With this compensation, the transmission quality required for a wireless communication system can be maintained.

Finally, the D / U estimation of this method is performed using the integrated value of all tap coefficients in the cross polarization interference compensator which is a part of the components of the demodulator. As a result, the signal level ratio D / U estimation accuracy can be kept constant regardless of the frequency characteristics of the interference signal, and the reliability of the transmission power control is enhanced.

(One specific example)
Next, a specific example of the wireless communication system according to the first embodiment will be described with reference to FIGS. 3 to 7. For convenience, the self-polarizing side will be described as V polarization. FIG. 3 shows a specific example of the wireless communication system shown in FIGS. 1 and 2. FIG. 4 is a block diagram showing a specific example of the data evaluation unit. FIG. 5 is a block diagram showing a specific example of the transmission side transmission power controller. FIG. 6 is a flowchart showing a method of generating a transmission power up / down control signal. FIG. 7 is a block diagram showing a specific example of the V polarization demodulator.

As shown in FIG. 3, the wireless communication system 1a includes a transmitting station 21 and a receiving station 22.

The transmission station 21 includes a V-polarization modulator 11, a V-polarization demodulator 12, a V-polarization transmitter 13, a V-polarization receiver 14, a transmission-side transmission power controller 15, and H-polarization. A transmitter 33 is provided. Further, the transmitting station 21 may include an H polarization modulator 40, an H polarization demodulator 41, and an H polarization receiver 42.

The receiving station 22 includes a V-polarized wave receiver 16, a V-polarized wave demodulator 17, a V-polarized wave modulator 18, a V-polarized wave transmitter 19, a data evaluation unit 20, and an H-polarized wave receiver 36. And an H polarization demodulator 37. Further, the receiving station 22 may include an H polarization transmitter 43 and an H polarization modulator 44.

The V polarization modulator 11 modulates an I (In-phase) / Q (Quadrature) baseband signal to generate a modulated signal. The V-polarization modulator 11 sends this modulated signal to the V-polarization transmitter 13. The V polarization transmitter 13 up-converts the transmitted modulation signal to the radio frequency band and sends it to the antenna 21a.

The signal passing through the radio propagation path 3 between the antenna 21a and the antenna 22a is received by the V polarization receiver 16 of the receiving station 22. The V-polarized light receiver 16 down-converts the received signal in the radio frequency band and sends it to the V-polarized light demodulator 17 on the self-polarizing side and the H-polarized light demodulator 37 on the differently polarized side.

The data evaluation unit 20 obtains a D / U estimated value V_DU of V polarization from the V polarization demodulator 17. The data evaluation unit 20 obtains a D / U estimated value H_DU of H polarization from the H polarization demodulator 37. The data evaluation unit 20 generates the status signal DATA2 based on the V-polarized D / U estimated value V_DU and the H-polarized D / U estimated value H_DU. Further, the data evaluation unit 20 generates the status signal DATA2 and also generates the transmission power control signal DATA1 based on the received signal level V_RSL and the received signal level H_RSL. The data evaluation unit 20 obtains the received signal level V_RSL from the V polarization receiver 16 and the received signal level H_RSL from the H polarization receiver 36. Further, the data evaluation unit 20 sends the transmission power control signal DATA1 and the status signal DATA2 to the V polarization modulator 18.

The V-polarization modulator 18 multiplexes the transmission power control signal DATA1 and the status signal DATA2 in the overhead of the radio, and then converts the transmission power control signal DATA1 into I / Q data for modulation. The V-polarization modulator 18 transmits the modulated transmission power control signal DATA1 and status signal DATA2 to the transmission station 21 via the V-polarization transmitter 19, antennas 21a and 22a, and the V-polarization receiver 14. It is sent to the V polarization demodulator 12.

The transmission side transmission power controller 15 has a self-polarizing side V polarization transmitter 13 and a different polarization side based on the transmission power control signal DATA1 and the status signal DATA2 obtained from the V polarization demodulator 12. The transmission power is controlled by the H polarization transmitter 33 of the above.

(Example of one configuration of the main part)
FIG. 4 shows a configuration example of the data evaluation unit 20. As shown in FIG. 4, the data evaluation unit 20 includes a detector 100, a comparator 101, and a controller 102.

The detector 100 compares the received signal levels V_RSL and H_RSL obtained from the V-polarized wave receiver 16 and the H-polarized wave receiver 36, respectively, and detects one of the lower received signal levels V_RSL and H_RSL.

The comparator 101 compares the magnitude of one of the detected received signal levels V_RSL and H_RSL with the reference value RSL_th.

The controller 102 generates the transmission power control signal DATA1 of both polarizations based on the comparison result by the comparator 101. Further, the controller 102 is based on the vertically polarized D / U estimated value V_DU input from the V polarization demodulator 17 and the D / U estimated value H_DU input from the H polarized wave demodulator 37. A status signal DATA2 indicating the interference state of each polarized wave is generated.

Subsequently, an operation example of each configuration of the data evaluation unit 20 described above will be described.

First, the detector 100 detects the lower signal level by comparing the received signal levels V_RSL and H_RSL of both polarized waves. Further, the detector 100 sends one of the detected received signal levels V_RSL and H_RSL to the comparator 101. The comparator 101 compares one of the transmitted received signal levels V_RSL and H_RSL with the reference value RSL_th. Based on this comparison result, the controller 102 generates a transmission power control signal DATA1 for increasing or decreasing the transmission output of both polarizations on the transmitting station side. The transmission power control signal DATA1 is, for example, 1-bit information, and may indicate the content indicating 1 or 2 described below.

1. 1. When min (V_RSL, H_RSL) ≤ RSL_th is established, DATA1 = "1 (up)" increases the transmission output of both polarizations of the opposite station (here, transmission station 21).
2. 2. When min (V_RSL, H_RSL)> RSL_th is established, DATA1 = “0 (down)” The transmission output of both polarizations of the opposite station (here, transmission station 21) is reduced.
Note that min (a, b) means the minimum value of a, b.
In other words, the transmission power control signal DATA1 increases the transmission power of V-polarized light and the transmission power of H-polarized light when one of the received signal levels V_RSL and H_RSL has a lower signal level than the reference value RSL_th. Show instructions. The transmission power control signal DATA1 indicates an instruction to reduce the transmission power of V polarization and the transmission power of H polarization when one of the reception signal levels V_RSL and H_RSL having a lower signal level is larger than the reference value RSL_th. ..

Subsequently, the controller 102 refers to the D / U estimated values V_DU and H_DU of the respective polarizations estimated by the V polarization demodulator 17 and the H polarization demodulator 37. The controller 102 generates a status signal DATA2 indicating the interference state of each polarized wave from the absolute value | V_DU-H_DU | of the difference and the magnitude relationship between the D / U estimated values V_DU and H_DU. The status signal DATA2 is represented by, for example, 2 bits of information. DU_th is a reference signal for determining the presence or absence of a difference. The status signal DATA2 may indicate, for example, the content indicating any of 3 to 5 described below.

3. 3. When | V_DU-H_DU | ≦ DU_th is satisfied, there is no deterioration of the signal level ratio D / U biased to one of the V-polarized wave and the H-polarized wave. That is, it is considered that the V polarization and the H polarization are attenuated to the same extent in the radio propagation path 3. DATA2 = "00" is output. “DATA2 =“ 00 ”” indicates that adjustment of the signal level ratio D / U of V-polarized light and H-polarized wave is not necessary.
4. When | V_DU-H_DU |> DU_th and V_DU> H_DU are established, the H polarization is attenuated in the radio propagation path 3 as compared with the V polarization, and the signal level ratio D / U deterioration of the H polarization occurs. Consider it as. DATA2 = "11" is output. “DATA2 =“ 11 ”” indicates deterioration of the signal level ratio D / U of H polarization.
5. When | V_DU-H_DU |> DU_th and V_DU <H_DU are established, it is considered that the V polarization is attenuated in the radio propagation path 3 and the signal level ratio D / U deterioration of the V polarization has occurred. DATA2 = "10" is output. “DATA2 =“ 10 ”” indicates the signal level ratio D / U deterioration of V polarization.
In other words, the status signal DATA2 is V-biased when the absolute value | V_DU-H_DU | of the difference between the vertically polarized D / U estimated value V_DU and the horizontally polarized D / U estimated value H_DU | is equal to or less than the threshold value DU_th. An instruction to reduce the transmission power of the wave and the transmission power of the H-polarized light is shown.
Further, the absolute value | V_DU-H_DU | of the difference between the vertically polarized D / U estimated value V_DU and the horizontally polarized D / U estimated value H_DU | may be higher than the threshold value DU_th. In such a case, the status signal DATA2 is an instruction to reduce the transmission power of the polarized wave having the lower D / U estimated value among the vertically polarized wave D / U estimated value V_DU and the horizontally polarized wave D / U estimated value H_DU. Is shown. Specifically, the status signal DATA2 indicates an instruction to reduce the transmission power of the vertically polarized wave when the D / U estimated value V_DU of the vertically polarized wave is lower than the D / U estimated value H_DU of the horizontally polarized wave. The status signal DATA2 indicates an instruction to reduce the transmission power of the horizontally polarized wave when the D / U estimated value H_DU of the horizontally polarized wave is lower than the D / U estimated value V_DU of the vertically polarized wave.

(An example of one configuration of another main part)
FIG. 5 shows a configuration example of the transmission side transmission power controller 15. As shown in FIG. 5, the transmission side transmission power controller 15 includes an UP / DOWN control signal generator 103 and a controller 104.

The UP / DOWN control signal generator 103 acquires the transmission power control signal DATA1 from the receiving station 22. The UP / DOWN control signal generator 103 generates a transmission power UP / DOWN control signal based on the transmission power control signal DATA1 and the status signal DATA2 indicating the interference state of each polarized wave. The transmission power UP / DOWN control signal indicates an instruction to increase or decrease the transmission power of each of V-polarized light and H-polarized wave.

The controller 104 acquires the transmission power UP / DOWN control signal from the UP / DOWN control signal generator 103. The controller 104 generates transmission power control values TXPWR_CONT_V and TXPWR_CONT_H for each of V-polarized light and H-polarized wave based on the transmission power UP / DOWN control signal and the step signal PWR_STEP. The step signal PWR_STEP changes the transmission power of V-polarized light and H-polarized wave.

(Method of generating transmission power UP / DOWN control signal)
Subsequently, a method of generating a transmission power UP / DOWN control signal will be described with reference to FIG. FIG. 6 is a flowchart showing a generation flow of a transmission power UP / DOWN control signal. Table 1 shows each information in the generation flow of the transmission power UP / DOWN control signal.

When receiving an instruction to increase the transmission power of V-polarized light and H-polarized light based on the transmission power control signal DATA1 (step ST10: DATA1 (= `1`)), the V-polarized light and H-polarized light It is judged that the received electric field has deteriorated. In order to prioritize the recovery of the received electric field, an instruction is given to simultaneously increase the transmission power of the V-polarized wave and the H-polarized wave (step ST11).

On the other hand, when receiving an instruction from DATA1 to reduce the transmission power of V-polarized light and H-polarized wave (step ST10: DATA1 (= `0`)), the V-polarized light and H-polarized wave are referred to with reference to the status signal DATA2. Check each interference state of H polarization (step ST12). When it is determined that the signal level ratio D / U has deteriorated in any of the polarizations (step ST12: DATA2 (= `10`,` 11)), the signal level ratio D / U has deteriorated. Priority is given to the instruction to increase the transmission power of the wave (steps ST20, S21). When the improvement of the signal level ratio D / U is confirmed (step ST12: DATA2 (= `00`)), it is instructed to reduce the transmission power of V-polarized light and H-polarized wave at the same time (step ST22).

A specific control procedure will be described.
1. 1. When any of the received electric fields (received signal level V_RSL, H_RSL) is equal to or less than a predetermined reference value RSL_th, the transmission power of V-polarized light and H-polarized wave is increased at the same time.
2. 2. When the received electric field (received signal level V_RSL, H_RSL) is higher than the predetermined reference value RSL_th and the signal level ratio D / U of V-polarized light deteriorates, the transmission power of only V-polarized light is increased. This improves the signal level ratio D / U of V polarization.
3. 3. When the received electric field (received signal level V_RSL, H_RSL) is higher than the predetermined reference value RSL_th and the signal level ratio D / U of H-polarized light deteriorates, the transmission power of only H-polarized light is increased. This improves the signal level ratio D / U of H polarization.
4. When the received electric field (received signal level V_RSL, H_RSL) is higher than the predetermined reference value RSL_th and the signal level ratio D / U of V-polarized light and H-polarized light does not need to be adjusted, V-polarized light and H-biased. Simultaneously reduce the transmission power of the wave.

Finally, the controller 104 acquires the transmission power UP / DOWN control signal sent by the UP / DOWN control signal generator 103. The controller 104 generates transmission power control values TXPWR_CONT_V and TXPWR_CONT_H for each of V-polarized light and H-polarized wave based on the transmission power UP / DOWN control signal and the step signal PWR_STEP. The step signal PWR_STEP determines the fluctuation range of the transmission power UP / DOWN. The step signal PWR_STEP is a value preset as a parameter. The controller 104 controls the transmission power by sending the transmission power control values TXPWR_CONT_V and TXPWR_CONT_H to the V polarization transmitter 13 and the H polarization transmitter 33.

(An example of one configuration of another main part)
Next, a configuration example of the V polarization demodulator 17 will be described. FIG. 7 shows an example of the configuration of the V polarization demodulator 17. As shown in FIG. 7, the V polarization demodulator 17 includes a V polarization amplitude corrector 200, an H polarization amplitude corrector 201, a cross polarization interference compensator 202, and a D / U estimator 203. Be prepared.

The V polarization amplitude corrector 200 and the H polarization amplitude corrector 201 are arranged in front of the cross polarization interference compensator 202 due to the circuit configuration of the V polarization demodulator 17. The cross-polarization interference compensator 202 includes, for example, a transversal filter. It is preferable that a plurality of tap coefficients are set in this transversal filter. The V-polarization amplitude corrector 200 and the H-polarization amplitude corrector 201 are self-polarized (V-polarized in this example) and different-polarized (in this example, in this example) at the input stage of the cross-polarization interference compensator 202. The reception level of (H polarization) is controlled to be the same. Even if there is a difference in the reception level between the self-polarized light and the differently polarized wave due to this amplitude control, the integrated value of all tap coefficients in the cross-polarized wave interference compensator 202 is the amount of interference on the differently polarized wave side with respect to the self-polarized wave. The values are almost the same.

The D / U estimator 203 obtains the sum of squares of all tap coefficients Ci (i = 0,1,2, ..... n) of the cross-polarization interference compensator 202 to obtain the D / U of V-polarization. The estimated value V_DU is derived. By using all the tap coefficients of the interference compensator, accurate D / U estimation becomes possible regardless of the degree of frequency characteristic deterioration of the differently polarized signal.
V_DU = Σ | c _i | ² (i = 0,1,2, ‥‥‥‥ n)

As described above, according to the above-described embodiment, deterioration of communication quality can be suppressed.

Further, according to the above-described embodiment, by keeping the reception level of V-polarized light and H-polarized wave above a predetermined level by using relatively small bit information, characteristic deterioration due to thermal noise is reduced. do. Further, it is possible to reduce the deterioration of the signal level ratio D / U caused by the attenuation of one polarization depending on the condition of the radio propagation path 3. Further, the estimation accuracy of the D / U estimated values V_DU and H_DU used for the transmission power control is maintained at a constant quality regardless of the frequency characteristics of the interference signal and the influence of the amplitude difference between the differently polarized signal and the self-polarized signal. This has the effect of improving the reliability of transmission power control.

The H polarization demodulator 37 may have the same configuration as the above-mentioned V polarization demodulator 17 configuration example (see FIG. 7). When the H polarization demodulator 37 has such a configuration, an accurate H polarization D / U estimated value H_DU can be derived.

(Other embodiments, etc.)

Further, there is a transmission power control device 2 shown in FIG. The transmission power control device 2 includes a data evaluation unit 20 and a transmission side transmission power controller 15. The transmission power control device 2 can be used by being incorporated in a wireless communication system different from the wireless communication system 1. The data evaluation unit 20 is provided on the receiving station side. The transmission side transmission power controller 15 is provided on the transmission station side.

Further, the transmission power control device and the wireless communication system according to the above embodiment can be provided with the following hardware configurations. FIG. 9 is a diagram showing an example of a hardware configuration included in a transmission power control device and a wireless communication system. As described in the above-mentioned various embodiments of the processing procedure in the transmission power control device and the wireless communication system, the present invention may also be in the form of a processing method.

The transmission power control device shown in FIG. 9 includes a processor 301 and a memory 302 together with the interface 303. A part of the wireless communication system 1 described in the above-described embodiment and the control configuration of the transmission power control device 2 (see FIGS. 1 to 8) are executed by the processor 301 reading the control program stored in the memory 302. It will be realized by. That is, this program is a program for making the processor 301 function as a part of the wireless communication system 1 or a control configuration of the transmission power control device 2, for example, a detector 100 or the like, or a part thereof. It can be said that this program is a program for causing the wireless communication system 1 and the transmission power control device 2 to execute the processing in the control configuration or a part thereof.

The programs described above are stored using various types of non-transitory computer readable medium and can be supplied to a computer (a computer including an information notification device). Non-temporary computer-readable media include various types of tangible storage media. Examples of non-temporary computer-readable media include magnetic recording media (eg, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (eg, magneto-optical disks). Further, this example includes a CD-ROM (Read Only Memory), a CD-R, and a CD-R / W. Further, this example includes semiconductor memories (eg, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory)). The program may also be supplied to the computer by various types of transient computer readable medium. Examples of temporary computer-readable media include electrical, optical, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

Further, as described in the various embodiments described above, the procedure of processing in the wireless communication system and the transmission power control device, the present disclosure also includes the form as a control method of the wireless communication system and the transmission power control device. Can be taken. Further, it can be said that the above-mentioned program is a program for causing the wireless communication system and the transmission power control device to execute such a control method.

The present invention is not limited to the above embodiment, and can be appropriately modified without departing from the spirit. For example, in one operation example of the wireless communication system 1a according to the first embodiment described above, the self-polarizing side is V-polarized, but the self-polarizing side may be H-polarized. Further, the radio communication systems 1 and 1a according to the above embodiment transmit and receive vertically polarized waves and horizontally polarized waves, but the first polarized wave having a predetermined plane of polarization and the bias orthogonal to the first polarized wave. It may send and receive to and from the second polarized wave having a wave surface. In other words, the polarized waves transmitted and received by the wireless communication systems 1, 1a are not limited to vertically polarized waves and horizontally polarized waves.

1, 1a Wireless communication system 2 Transmission power controller 21 Transmitter station 21a Antenna 22 Receiver station 22a Antenna 3 Radio propagation path 11 V-polarization modulator 12 V-polarization demodulator 13 V-polarization transmitter 14 V-polarization receiver 15 Transmitter transmit power controller 16 V polarization receiver 17 V polarization demodulator 18 V polarization modulator 19 V polarization transmitter 20 Data evaluation unit 33 H polarization transmitter 36 H polarization receiver 37 H Polarization demodulator 100 Detector 101 Comparer 102 Controller 103 Control signal generator 104 Controller
200 V polarization amplitude compensator 201 H polarization amplitude compensator 202 cross polarization interference canceller 203 D / U estimator 301 processor 302 memory 303 interface ATT1, ATT2 attenuation C _i all tap coefficients DATA1 transmission power control signal DATA2 Status signals _D H, _{D V} main wave power DU square sum DU_th threshold D / U, H_D / U, V_D / U signal level ratio H_DU, V_DU estimate H_RSL, V_RSL received signal level PWR_STEP step signal
RSL_th reference value TXPWR_CONT_V transmission power control value _U H, _{U V} interference power ST10, ST11, ST12, ST20, ST22 step

Claims (10)

In a transmission power control device incorporated in a wireless communication system that employs a cross-polarization interference compensation method,
The wireless communication system includes a transmitting station and a receiving station.
The receiving station includes a vertically polarized wave demodulator and a horizontally polarized wave demodulator.
The transmission power control device includes a data evaluation unit incorporated in the receiving station and a transmitting side transmission power controller incorporated in the transmitting station.
The data evaluation unit includes a detector and a controller.
The detector detects one of the vertically polarized wave received signal level and the horizontally polarized wave received signal level, which has a lower signal level.
The controller generates a transmission power control signal so that one of the detected vertically polarized light received signal level and the horizontally polarized light received signal level is adjusted to a predetermined level, and the vertically polarized demodulator and the above. Based on the D / U estimated value calculated by the horizontal polarization demodulator, a status signal indicating the interference state of polarization is generated.
The transmission power control signal and the status signal are multiplexed and transmitted to the transmission side transmission power controller in a wireless frame.
Transmission power controller. The transmitting side transmission power controller generates a transmission power control value based on the transmission power control signal extracted from the radio frame and the status signal.
The transmission power control device according to claim 1. When the transmission power control signal indicates that one of the vertically polarized light received signal level and the horizontally polarized light received signal level detected by the detector is equal to or less than the reference value RSL_th.
The transmission side transmission power controller increases the transmission power of vertically polarized waves and the transmission power of horizontally polarized waves based on the transmission power control value.
The transmission power control device according to claim 2. The transmission power control signal indicates that one of the vertically polarized light received signal level and the horizontally polarized light received signal level detected by the detector is higher than the reference value RSL_th, and
When the status signal indicates that the absolute value | V_DU-H_DU | of the difference between the vertically polarized D / U estimated value V_DU and the horizontally polarized D / U estimated value H_DU is equal to or less than the threshold value DU_th.
The transmission side transmission power controller reduces the transmission power of vertically polarized waves and the transmission power of horizontally polarized waves based on the transmission power control value.
The transmission power control device according to claim 2. The transmission power control signal indicates that one of the vertically polarized light received signal level and the horizontally polarized light received signal level detected by the detector is higher than the reference value RSL_th, and
The status signal indicates that the absolute value | V_DU-H_DU | of the difference between the vertically polarized D / U estimated value and the horizontally polarized D / U estimated value is higher than the threshold value DU_th.
Based on the transmission power control value, the transmission side transmission power controller has a bias in which the D / U estimated value is lower than the vertically polarized D / U estimated value V_DU and the horizontally polarized D / U estimated value H_DU. Reduce wave transmission power,
The transmission power control device according to claim 2. In a wireless communication system that employs a cross-polarization interference compensation method,
It has a transmitting station and a receiving station.
The transmitting station includes a transmitting power controller on the transmitting side.
The receiving station includes a data evaluation unit, a vertically polarized wave demodulator, and a horizontally polarized wave demodulator.
The data evaluation unit includes a detector and a controller.
The detector detects one of the vertically polarized wave received signal level and the horizontally polarized wave received signal level, which has a lower signal level.
The controller generates a transmission power control signal so that one of the detected vertically polarized light received signal level and the horizontally polarized light received signal level is adjusted to a predetermined level, and the vertically polarized demodulator and the above. From the D / U estimated value calculated by the horizontal polarization demodulator, a status signal indicating the interference state of polarization is generated.
The transmission power control signal and the status signal are multiplexed and transmitted to the transmission station in a wireless frame.
Wireless communication system. At least one of the vertical polarization demodulator and the horizontal polarization demodulator includes a cross polarization interference compensator and a D / U estimator.
The D / U estimator estimates the D / U of at least one of the vertical polarization demodulator and the horizontal polarization demodulator by integrating all the tap coefficients of the cross polarization interference compensator. Deriving the value,
The wireless communication system according to claim 6. At least one of the vertical polarization demodulator and the horizontal polarization demodulator includes a cross polarization interference compensator and a D / U estimator.
The D / U estimator, the entire tap coefficients of the cross polarization interference compensator _{C i (i = 0,1,2, ‥‥‥‥} n) by obtaining the square sum DU of the vertically polarized wave demodulation To derive the D / U estimate of the polarization of at least one of the instrument and the horizontal polarization demodulator.
The wireless communication system according to claim 6. In the transmission power control method of a wireless communication system that employs a cross-polarization interference compensation method and has a transmitting station and a receiving station.
The receiving station includes a vertically polarized wave demodulator and a horizontally polarized wave demodulator.
A step of detecting which of the vertically polarized wave received signal level and the horizontally polarized wave received signal level received by the receiving station has a lower signal level, and
A step of generating a transmission power control signal so that one of the detected vertically polarized wave received signal level and horizontally polarized wave received signal level is adjusted to a predetermined level, and
A step of generating a status signal indicating a polarization interference state from the D / U estimated values calculated by the vertically polarized wave demodulator and the horizontally polarized wave demodulator, and
The step includes a step of multiplexing the transmission power control signal and the status signal to the transmission station in a wireless frame and transmitting the signal to the transmission station.
Transmission power control method for wireless communication systems. Operates as a transmission power controller built into a wireless communication system that employs cross-polarization interference compensation,
The wireless communication system includes a transmitting station and a receiving station.
The receiving station is a computer equipped with a vertically polarized wave demodulator and a horizontally polarized wave demodulator.
A step of detecting which of the vertically polarized wave received signal level and the horizontally polarized wave received signal level received by the receiving station has a lower signal level, and
A step of generating a transmission power control signal so that one of the detected vertically polarized wave received signal level and horizontally polarized wave received signal level is adjusted to a predetermined level, and
A step of generating a status signal indicating a polarization interference state from the D / U estimated values calculated by the vertically polarized wave demodulator and the horizontally polarized wave demodulator, and
The step of multiplexing and transmitting the transmission power control signal and the status signal to the transmission station in a wireless frame is executed.
program.

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