WO2010134265A1

WO2010134265A1 - Wireless communication apparatus, wireless communication method, and non-transitory computer readable medium in which communication control program is stored

Info

Publication number: WO2010134265A1
Application number: PCT/JP2010/002894
Authority: WO
Inventors: 片貝陽一; 川合雅浩
Original assignee: 日本電気株式会社
Priority date: 2009-05-20
Filing date: 2010-04-22
Publication date: 2010-11-25

Abstract

Disclosed are a wireless communication apparatus, wireless communication method, and communication control program, wherein changes in the state of a communication channel can be estimated directly. The wireless communication apparatus is a wireless communication apparatus which performs co-channel transmission using orthogonally polarized signals. The wireless communication apparatus is provided with a polar signal reception unit (1) which receives one of the polarized signals transmitted to the wireless communication apparatus as a polar signal, and a cross polar signal reception unit (2) which receives a cross polar signal which is orthogonal to the polar signal that the polar signal reception unit (1) receives. Further, the wireless communication apparatus is provided with a communication channel status estimation unit (3) which estimates the state of the communication channel, based on information pertaining to the cross-polarization interference generated between the polar signal received by the polar signal reception unit (1) and the cross polar signal received by the cross polar signal reception unit (2).

Description

Non-transitory computer-readable medium storing wireless communication apparatus, wireless communication method, and communication control program

The present invention relates to a wireless communication device, a wireless communication method, and a communication control program, and more particularly, to a wireless communication device that performs co-channel transmission, a wireless communication method, and a non-transitory computer-readable medium storing a communication control program.

In co-channel transmission using orthogonal polarization in a digital microwave fixed communication system, a transmitter and a receiver that transmit and receive one polarization of the orthogonal polarization, and a transmitter and receiver that transmit and receive the other polarization Consists of a receiver.

Here, the technology for improving the quality when performing co-channel transmission is described below.

Patent Document 1 discloses a technique for compensating for inter-polarization interference that occurs in co-channel transmission using orthogonal polarized waves. One of the orthogonal polarization signals is a self-polarization signal, and the other polarization signal is a different polarization signal. At this time, the characteristic deterioration is improved by compensating the cross-polarization interference component generated by the cross-polarization signal leaking into the self-polarization signal from the self-polarization signal. When compensating cross-polarization interference components from the self-polarization signal, cross-polarization based on the coefficient obtained from the correlation between the error signal and cross-polarization signal generated in the self-polarization signal due to the influence of the cross-polarization interference component The interference component is compensated from the self-polarized signal.

Patent Document 2 discloses an adaptive modulation control apparatus that selects one channel coding rate from a plurality of channel coding rates based on an input received power ratio and an input interference power to noise power ratio.

Patent Document 3 discloses contents for determining a communication rate based on an error rate of received data and a good communication environment. Specifically, the wireless communication device performs threshold determination of the communication environment goodness, and changes the communication rate to a higher communication rate when the communication environment goodness exceeds the threshold. At this time, when the error rate is high, the wireless communication apparatus increases the communication environment goodness threshold, and when the error rate is low, the wireless communication apparatus decreases the communication environment goodness threshold. This prevents the error rate from becoming high due to the increase in the communication rate due to the adaptive modulation method, but increases the communication rate when the error rate is originally low and there is no need to keep the error rate low. Can be made.

Non-Patent Document 1 discloses a configuration of a wireless communication device of a digital microwave fixed communication system.

JP 2004-112288 A JP 2007-281780 A JP 2007-324651 A

However, the following problems arise when the techniques disclosed in Patent Documents 1 to 3 described above are used. In co-channel transmission using orthogonal polarization in a digital microwave fixed communication system, the wireless communication device uses the error rate of the signal after compensating for the cross-polarization interference component from its own polarization signal, Is estimated. At this time, the wireless communication apparatus estimates the transmission path state using the signal after the control for compensating for the influence due to the state change of the transmission path is performed. That is, the wireless communication apparatus estimates the transmission path state using the own polarization signal after compensating for the cross polarization interference component caused by the transmission path state change, and accurately estimates the transmission path state change. I can't.

The present invention has been made to solve such a problem, and a wireless communication device, a wireless communication method, and a communication control program that can accurately estimate a state change of a transmission path are stored. It is an object to provide a typical computer readable medium.

A wireless communication apparatus according to a first aspect of the present invention is a wireless communication apparatus that performs co-channel transmission using orthogonal polarization signals, and one of the transmitted polarization signals is used as its own polarization signal. A self-polarization signal receiving unit for receiving, a cross-polarization signal receiving unit for receiving a cross-polarization signal orthogonal to the self-polarization signal received by the self-polarization signal receiving unit, and the self-polarization signal receiving unit A transmission path state estimation unit that estimates a transmission path state based on information on inter-polarization interference generated between the received polarization signal and the cross polarization signal received by the cross polarization signal reception unit; It is to be prepared.

The wireless communication apparatus according to the second aspect of the present invention is a wireless communication apparatus that performs co-channel transmission using orthogonal polarization signals, and one of the transmitted polarization signals is converted to its own polarization. A self-polarization signal receiving unit that receives the signal as a signal, a cross-polarization signal receiving unit that receives a cross-polarization signal orthogonal to the self-polarization signal received by the self-polarization signal reception unit, and the self-polarization signal reception An inter-polarization interference compensation unit that compensates for the inter-polarization interference generated between the own-polarization signal received by the unit and the cross-polarization signal received by the cross-polarization signal reception unit, and the inter-polarization interference compensation unit And a transmission path state estimation unit that estimates a transmission path state based on a weighting factor used to compensate for interference between polarizations.

A wireless communication method according to the third aspect of the present invention is a wireless communication method that performs co-channel transmission using orthogonal polarization signals, and a self-polarization signal that is one of the polarization signals and A step of detecting inter-polarization interference generated between the self-polarization signal and a cross-polarization signal orthogonal to the self-polarization signal, and a step of estimating a transmission path state based on the information on the inter-polarization interference.

A non-transitory computer readable medium storing a communication control program according to the fourth aspect of the present invention is a communication control program used for a wireless communication apparatus that performs co-channel transmission using orthogonal polarization signals. A step of acquiring information relating to inter-polarization interference that occurs between a self-polarization signal that is one of the polarization signals and a cross-polarization signal that is orthogonal to the self-polarization signal; and A step of estimating a transmission line state based on information; and a step of setting a data rate of a transmission signal in accordance with the transmission line state estimated based on the information on the inter-polarization interference. A communication control program to be executed is stored.

According to the present invention, it is possible to provide a non-transitory computer-readable medium storing a wireless communication apparatus, a wireless communication method, and a communication control program that can accurately estimate a state change of a transmission path.

1 is a configuration diagram of a wireless communication apparatus according to a first exemplary embodiment. 1 is a configuration diagram of a wireless communication apparatus according to a first exemplary embodiment. FIG. 6 is a diagram illustrating an operation related to compensation for inter-polarization interference according to the first exemplary embodiment; FIG. 6 is a diagram for explaining an error signal according to the first embodiment. FIG. 3 is a configuration diagram of a weighting factor determination unit according to the first exemplary embodiment. 3 is an information table used for determining a data rate according to the first embodiment; FIG. 6 is a diagram for explaining modulation scheme switching according to the first embodiment; FIG. 3 is a configuration diagram of a wireless communication apparatus according to a second exemplary embodiment. FIG. 6 is a configuration diagram of a wireless communication apparatus according to a third embodiment. It is a flowchart concerning data rate determination.

(Embodiment 1)
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a wireless communication apparatus according to Embodiment 1 of the present invention. The wireless communication device is a wireless communication device that performs co-channel transmission using orthogonal polarization signals. The wireless communication apparatus includes an own polarization signal receiving unit 1, a cross polarization signal receiving unit 2, a transmission path state estimation unit 3, and an antenna 10.

The own polarization signal receiving unit 1 receives one of the polarization signals transmitted from other wireless communication apparatuses as an own polarization signal via the antenna 10. The received own polarization signal is output to the transmission path state estimation unit 3.

The cross polarization signal receiving unit 2 is a polarization signal transmitted from another wireless communication device, and receives a cross polarization signal orthogonal to the own polarization signal via the antenna 10. The received cross polarization signal is output to the transmission path state estimation unit 3. In FIG. 1, the antenna 10 receives the self-polarized signal and the cross-polarized signal. However, two or more antennas may be provided, and the self-polarized signal and the cross-polarized signal may be received by different antennas. .

The transmission path state estimation unit 3 uses the information regarding the inter-polarization interference generated between the own polarization signal received by the own polarization signal reception unit 1 and the cross polarization signal received by the cross polarization signal reception unit 2. Based on this, the transmission path state is estimated. Specifically, the self-polarized signal and the cross-polarized signal are transmitted orthogonally, but an event occurs that the cross-polarized signal leaks into the self-polarized signal due to the deterioration of the transmission path condition or the like. . As a result, the self-polarized signal receives interference from the cross-polarized signal. Here, as information on the inter-polarization interference between the self-polarized signal and the cross-polarized signal, for example, when the amount of interference or the weight coefficient used for compensation of the inter-polarization interference is large, the transmission path state estimation unit 3 Judge that the condition is getting worse. When the amount of interference or the weighting coefficient used for compensating for the polarization interference is small, the transmission path state estimation unit 3 determines that the transmission path state is stable.

As described above, by using the radio communication apparatus having the configuration shown in FIG. 1, it is possible to accurately estimate the transmission path state from the information related to the interference between the polarizations of the received own polarization signal and cross polarization signal.

Next, the detailed configuration of the wireless communication apparatus according to the first embodiment of the present invention will be described with reference to FIG. The wireless communication apparatus includes an antenna 10, an own polarization signal receiving unit 11, a power control unit (hereinafter referred to as AGC (Automatic Gain Control)) 12, a polarization signal receiving unit 21, an AGC 22, and an equalizer 31. Cross polarization interference compensator (hereinafter referred to as XPIC (Cross Polarization Interference Canceller)) 32, polarization signal coupling unit 33, error detection unit 34, interference amount calculation unit 35, data rate control unit 41, and modulation A unit 42 and a transmission unit 43 are provided. Here, the own polarization signal receiving unit 1 of FIG. 1 includes an own polarization signal receiving unit 11 and an AGC 12, and the cross polarization signal receiving unit 2 includes a cross polarization signal receiving unit 21 and an AGC 22. The transmission path state estimation unit 3 includes an equalizer 31, an XPIC 32, a polarization signal coupling unit 33, an error detection unit 34, and an interference amount calculation unit 35.

The own polarization signal receiving unit 11 receives one of the polarization signals transmitted from other wireless communication devices as the own polarization signal. The own polarization signal receiving unit 11 converts an RF (Radio-Frequency) signal received by the antenna 10 into a baseband signal and outputs the baseband signal to the AGC 12. The AGC 12 that has acquired the own polarization signal converges the received power of the own polarization signal to a certain output level. The AGC 12 outputs a signal subjected to power control to the equalizer 31.

The cross polarization signal receiving unit 21 receives a polarization signal orthogonal to the self polarization signal as a cross polarization signal. The cross polarization signal receiving unit 21 converts an RF (Radio Frequency) signal received by the antenna 10 into a baseband signal and outputs the baseband signal to the AGC 22. The AGC 22 that has acquired the cross polarization signal converges the received power of the cross polarization signal to a constant output level. The AGC 22 outputs a signal subjected to power control to the XPIC 32.

The equalizer 31 removes intersymbol interference of the own polarization signal acquired from the AGC 12. For example, the equalizer 31 is a transversal type automatic equalizer. The transversal type automatic equalizer removes mutual interference between bits caused by multipath or the like. Here, the equalizer 31 removes intersymbol interference using error information from the ideal reception signal point of the own polarization signal detected by the error detection unit 34 described later. The equalizer 31 outputs the own polarization signal from which the intersymbol interference is removed to the polarization signal coupling unit 33.

The XPIC 32 generates a component that compensates for the cross polarization interference included in the own polarization signal based on the cross polarization signal acquired from the AGC 22, and outputs the generated component to the polarization signal coupling unit 33. The polarization signal combining unit 33 combines the component that compensates the cross-polarization interference acquired from the XPIC 32 with the self-polarization signal acquired from the equalizer 31, and generates a self-polarization signal that eliminates the cross-polarization interference. . The polarization signal coupling unit 33 outputs the own polarization signal compensated for the cross polarization interference to the error detection unit 34. Here, operations of the XPIC 32, the polarization signal coupling unit 33, and the error detection unit 34 will be described in detail with reference to FIG.

The XPIC 32 includes a weighting factor determination unit 321, delay units 322_1 to 322_2N + 1, multipliers 323_1 to 323_2N + 1, and adders 324_1 to 324_2N + 1.

The cross polarization signal X _j input to the XPIC 32 is input to the delay units 322_1 to 322_2N + 1, and 2N + 1 cross polarization signals (X ₋ ) acquired at N times before and after T around a certain time T. _{N 1} to X _N ). Further, the cross polarization signal X _j is also input to the weighting factor determination unit 321. Cross-polarized signals X _{−N 1} to X _N are input to multipliers 323_1 to 323_2N + 1, and are multiplied by the weighting factor acquired from weighting factor determining section 321. Multipliers 323_1 to 323_2N + 1 multiply the cross polarization signals X _−N to X _N by weighting factors to calculate the ratio of the inter-polarization interference in the cross polarization signals X _−N to X _N.

Multipliers 323_1 to 323_2N + 1 output the result of multiplying the cross polarization signal and the weighting coefficient to adders 324_1 to 324_2N + 1. Adders 324_1 to 324_2N + 1 add all the values output from multipliers 323_1 to 323_2N + 1. Thereby, the inter-polarization interference between the own polarization signal and the cross polarization signal is calculated. The adder 324_2N + 1 outputs the calculated inter-polarization interference to the polarization signal coupling unit 33.

The polarization signal coupling unit 33 adds (or subtracts) the inter-polarization interference acquired from the adder 324_2N + 1 to the own polarization signal (D _in ) acquired from the equalizer 31 and leaks into the own polarization signal. Compensate for inter-polarization interference. The own polarization signal (D _out ) generated by the polarization signal coupling unit 33 is output to the error detection unit 34.

Here, the calculation method of the weighting coefficient will be described with reference to FIGS. FIG. 4 shows the self-polarized signal (D _in ) acquired from the equalizer 31 and the self-polarized signal (D _out ) compensated for inter-polarization interference on the IQ plane. Further, FIG. 4 also shows ideal received signal points of a signal transmitted by QPSK modulation on the IQ plane. If the ideal reception signal point is a signal transmitted by QPSK modulation, a signal whose components are (1, 1) (1, -1) (-1, 1) (-1, -1) on the IQ plane It is determined as a point. Error detector 34, the own polarization signal _{(D out),} is detected as an error signal the difference between the distance of the nearest ideal signal point from the own polarization signal _{(D out) (E).} The error detector 34 outputs the detected error signal to the equalizer 31 and the XPIC 32.

Next, a configuration example of the weight coefficient determination unit 321 of the XPIC 32 will be described with reference to FIG. The weighting factor determination unit 321 includes a correlation calculation unit 321_1 and an integration unit 321_2.

The correlation calculation unit 321_1 calculates the correlation between the error signal (E) acquired from the error detection unit 34 and the cross polarization signals X _{−N 1} to X _N. Specifically, correlation calculation section 321_1 calculates the inner product value (E · X _j (−N ≦ j ≦ N)) of each cross-polarized signal X _{−N 1} to X _N and error signal (E). Next, the weight coefficient C _j is calculated from the inner product value and the absolute value of X _j using the following equation (1).

The weighting coefficient C _j calculated by the equation (1) indicates the ratio of the inter-polarization interference included in the cross polarization signal X _j . Further, C _j will be further described. The cross polarization signal stored in the delay units 322_1 to 322_2N + 1 changes at regular intervals. For example, the cross polarization signal X _j stored in the delay unit 322_1 moves to the delay unit 322_2 when the cross polarization signal X _{j + 1} is acquired. The cross polarization signal X _{j + 1} is stored in the delay unit 322_1. In this way, every time a cross-polarized signal is acquired, the cross-polarized signal stored in the delay units 322_1 to 322_2N + 1 changes. Therefore, the integration unit 321_2 calculates the sum of the weighting coefficients of the delay unit 322_j (1 ≦ j ≦ 2N + 1) for a certain time. Specifically, the sum of the weighting coefficients is expressed by the following equation (2).

Α in Equation (2) is an arbitrary coefficient. Z is an arbitrary value and indicates the number of times to be added before a predetermined time elapses. Weight coefficient determination unit 321 outputs the weighting coefficients _{C j} calculated in this way to multipliers 323_1 ~ 323_2N + 1.

Returning to FIG. 2, the XPIC 32 outputs the calculated 2N + 1 weighting factors C _j to the interference amount calculation unit. The interference amount calculation unit 35 calculates the total sum of the acquired weighting factors _Cj using Expression (3).

The interference amount calculation unit 35 outputs the sum of the weighting factors C _j calculated by the equation (3) to the data rate control unit 41. The total sum of the weighting factors C _j indicates the amount of interference between the polarized waves.

The data rate control unit 41 determines the data rate based on the sum value of the weighting factors _Cj . Specifically, the data rate control unit 41 determines, for example, the modulation method and the modulation rate based on the information table that defines the relationship between the sum of the weight coefficients, the modulation method, and the modulation rate in FIG. C1 to C3 indicating the sum of the weighting coefficients have a relationship of C1 <C2 <C3. When the sum of the weighting coefficients acquired from the interference amount calculation unit 35 is smaller than C1, the data rate control unit 41 determines that the state of the transmission path is stable, sets the modulation scheme to 16QAM, and sets the modulation speed to 3 Mbaud. Set a high data rate. Further, when the sum of the weighting coefficients acquired from the interference amount calculation unit 35 is larger than C3, the data rate control unit 41 determines that the state of the transmission path is unstable, sets the modulation method to QPSK, and modulates the modulation. A low data rate with a speed of 1 Mbaud is set. The setting values of the modulation scheme and modulation speed shown in FIG. 6 are merely examples, and the data rate control unit 41 can set other modulation schemes and modulation speeds. Alternatively, the data rate control unit 41 may set one of the modulation scheme and the modulation speed.

The modulation unit 42 modulates transmission data based on the modulation scheme and modulation speed set by the data rate control unit 41. The modulation unit 42 outputs the modulated transmission data to the transmission unit 43. The transmission unit 43 transmits the acquired transmission data via the antenna 10.

As described above, the radio communication apparatus according to the first embodiment of the present invention calculates the interpolarization interference generated between the own polarization signal and the cross polarization signal, and is based on the weighting factor indicating the interpolarization interference. Thus, it is possible to accurately grasp the transmission path state.

In addition, the wireless communication apparatus according to the first embodiment of the present invention directly grasps the transmission path state. For example, if the transmission path state is unstable, the data rate is set to a low speed and the transmission path state is stable. If so, an appropriate data rate can be set, such as setting the data rate at a high speed.

In addition, the wireless communication apparatus according to the first embodiment of the present invention grasps the transmission path state based on the weight coefficient indicating the inter-polarization interference generated in the own polarization signal before compensating for the inter-polarization interference. Thus, the transmission path state can be grasped quickly and directly. The weighting coefficient indicating the inter-polarization interference is generated when the inter-polarization interference is compensated, and is not obtained by a circuit newly provided for the present invention. Thus, it is possible to grasp the transmission path state without greatly increasing the circuit scale. Furthermore, the data rate can be controlled at an early stage by quickly grasping the transmission path state. This will be specifically described with reference to FIG.

Fig. 7 shows the relationship between the passage of time and the sum of the weighting factors. C0 indicates a threshold value for switching the data rate. C1 represents the total sum of the weight coefficients of the control limits that the XPIC 32 can perform cross polarization compensation. When the transmission path state is not grasped based on the weighting factor according to the first exemplary embodiment of the present invention, after the sum of the weighting factors exceeds the control limit C1 at which cross-polarization interference can be compensated, An error is detected. That is, until the control limit C1, the XPIC 32 compensates for cross-polarization interference caused by an unstable transmission path state, so that many code errors do not occur. Therefore, the data rate control unit 41 sets a 16QAM modulation scheme that realizes, for example, a high data rate until the sum of the weight coefficients reaches the control limit C1 (A).

On the other hand, when the transmission path state is grasped based on the weighting factor according to the first embodiment of the present invention, the transmission path state is determined to be unstable at the threshold value C0 before reaching the control limit C1, Switch the data rate. Here, a QPSK modulation scheme that realizes a low data rate is set at the time when the sum of the weight coefficients reaches C0 (B). As a result, a control time difference of time T occurs between when the transmission path state is grasped based on the weighting coefficient and when it is not. Further, by switching the modulation method at an early stage, it is possible to improve an event in which the error rate suddenly increases when the control limit C1 is exceeded and the data rate control cannot keep up with the change in the state of the transmission path.

(Embodiment 2)
Next, a configuration example of the wireless communication apparatus according to the second exemplary embodiment of the present invention will be described using FIG. The wireless communication apparatus according to the second embodiment of the present invention outputs power control information from the AGC 12 to the data rate control unit 41. The AGC 12 converges the received power of the own polarization signal to a certain output level. That is, the AGC 12 amplifies the power when the received power of the received polarization signal is lower than a predetermined value. The received power of the self-polarized signal received by the wireless communication apparatus is attenuated by the influence of the distance of the wireless transmission path for communication and the buildings existing on the transmission path. The AGC 12 outputs power control information to the data rate control unit 41. For example, the AGC 12 may output a power difference between a predetermined power value and the received power of the received own polarization signal to the data rate control unit 41. Alternatively, the AGC 12 may output the received power value of the received own polarization signal to the data rate control unit 41.

The data rate control unit 41 determines the modulation scheme and the modulation speed based on the power control information acquired from the AGC 12 and the weighting factor that is information on the interference between polarizations.

As described above, the radio communication apparatus according to the second embodiment of the present invention can determine the data rate based on the power control information and the information on the interference between polarizations. The wireless communication apparatus according to the second embodiment of the present invention can accurately determine the transmission path state by increasing the parameters for determining the data rate, and therefore can determine an appropriate data rate. .

(Embodiment 3)
Next, a configuration example of the wireless communication apparatus according to the third embodiment of the present invention will be described with reference to FIG. The wireless communication apparatus according to the third embodiment of the present invention includes an error detection unit 50. Other configurations are the same as those in FIGS. 2 and 8.

The error detection unit 50 acquires the own polarization signal compensated for the inter-polarization interference from the polarization signal coupling unit 33. The error detection unit 50 detects a code error included in the acquired own polarization signal. For example, a code error may be detected based on CRC (Cyclic Redundancy Check). The code error detection method is not limited to the CRC, and other methods may be used to detect the code error. The error detection unit 50 outputs information regarding the detected code error to the data rate control unit 41. For example, the error detection unit 50 may output the number of bits of the generated error to the data rate control unit 41. Alternatively, an error rate indicating the number of generated error bits as a percentage may be output to the data rate control unit 41.

The data rate control unit 41 is based on the information regarding the code error acquired from the error detection unit 50, the power control information acquired from the AGC 12, and the weighting factor that is the information regarding the inter-polarization interference acquired from the interference amount calculation unit 35. Determine the data rate.

As described above, the radio communication apparatus according to the third embodiment of the present invention can determine the data rate based on the code error information, the power control information, and the information on the inter-polarization interference. The wireless communication apparatus according to the third embodiment of the present invention can accurately determine the transmission path state by increasing parameters when determining the data rate, and therefore can determine an appropriate data rate. .

In Embodiments 1 to 3 described above, the present invention has been described as a hardware configuration, but the present invention is not limited to this. The present invention can also realize arbitrary processing by causing a computer including a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a DSP (Digital Signal Processor), and the like to execute a program. In the above example, the program can be stored and supplied to a computer using various types of non-transitory computer readable media. Non-transitory computer readable media include various types of tangible storage media (tangible storage medium). Examples of non-transitory computer-readable media include magnetic recording media (eg flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (eg magneto-optical discs), CD-ROMs (Read Only Memory), CD-Rs, CD-R / W, semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable ROM), flash ROM, RAM (Random Access Memory)) are included. The program may also be supplied to the computer by various types of temporary computer-readable media. Examples of transitory computer readable media include electrical signals, optical signals, 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.

Here, as an example, a procedure for causing the computer to execute the processing content for setting the data rate based on the information on the interference between polarizations will be described with reference to FIG.

In step S1, the computer obtains 2N + 1 weighting factors C _j from the XPIC 32. In step S2, the computer calculates the sum of the acquired weighting factors _Cj . In step S3, the computer compares the sum of the weighting factors C _j, a predetermined threshold value. In step S4, when the sum of weighting coefficients C _j is smaller than a predetermined threshold, the computer determines a stable channel state, for example, select a 16QAM modulation scheme, to set the high-speed data rates. In step S5, if the sum of weighting coefficients C _j is larger than a predetermined threshold value, the computer determines that the transmission path condition is unstable, for example, select the QPSK modulation scheme, sets the low-speed data rates .

Note that the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.

The present invention has been described above with reference to the embodiment, but the present invention is not limited to the above. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the invention.

This application claims priority based on Japanese Patent Application No. 2009-121722 filed on May 20, 2009, the entire disclosure of which is incorporated herein.

DESCRIPTION OF SYMBOLS 1 Self-polarization signal receiver 2 Cross-polarization signal receiver 3 Transmission path state estimation part 11 Self-polarization signal receiver 12 Power control part 21 Cross-polarization signal reception part 22 Power control part 31 Equalizer 32 Between cross-polarizations Interference compensator 33 Polarization signal coupling unit 34 Error detection unit 35 Interference amount calculation unit 41 Data rate control unit 42 Modulation unit 43 Transmission unit 50 Error detection unit 321 Weight coefficient determination unit 321_1 Correlation calculation unit 321_2 Integration units 322_1 to 322_2N + 1 Delay unit 323_1 to 323_2N + 1 multipliers 324_1 to 324_2N + 1 adders

Claims

A wireless communication device that performs co-channel transmission using orthogonal polarization signals,
An own polarization signal receiving means for receiving one of the transmitted polarization signals as an own polarization signal;
A cross-polarization signal receiving means for receiving a cross-polarization signal orthogonal to the self-polarization signal received by the self-polarization signal receiving means;
A transmission path state is estimated based on information on the inter-polarization interference generated between the own polarization signal received by the own polarization signal receiving unit and the cross polarization signal received by the cross polarization signal receiving unit. A wireless communication apparatus comprising: a transmission path state estimation unit.
The transmission path state estimation means transmits based on the amount of interference generated between the own polarization signal received by the own polarization signal reception means and the cross polarization signal received by the cross polarization signal reception means. The wireless communication apparatus according to claim 1, wherein the road condition is estimated.
3. The wireless communication apparatus according to claim 1, further comprising data rate control means for setting a data rate of a transmission signal in accordance with the transmission path state estimated by the transmission path state estimation means.
Interference compensation means for compensating for inter-polarization interference generated between the own polarization signal and the cross polarization signal from the own polarization signal received by the own polarization signal receiving means;
Error detecting means for detecting an error between the own polarization signal compensated for inter-polarization interference by the interference compensation means and a predetermined reference signal;
The interference compensation means includes
Based on the error detected by the error detection means, the own polarization signal received next to the own polarization signal received by the own polarization signal reception means and the cross polarization signal received by the cross polarization signal reception means. The radio communication apparatus according to any one of claims 1 to 3, wherein inter-polarization interference occurring with a wave signal is compensated.
5. The radio communication apparatus according to claim 4, wherein the transmission path state estimation means estimates the transmission path state based on a weighting factor used by the interference compensation means for compensation of interpolarization interference from the own polarization signal. .
Further comprising power control means for controlling the received power of the own polarization signal received by the own polarization signal receiving means to converge to a predetermined power,
The data rate setting means sets the data rate of the transmission signal based on the power controlled by the power control means in addition to the transmission path state estimated by the transmission path state estimation means. Item 6. The wireless communication device according to any one of Items 3 to 5.
The data rate setting means generates a self-polarized signal from which inter-polarization interference has been removed by the interference compensation means in addition to the transmission path state estimated by the transmission path state estimation means and the power controlled by the power control means. 7. The wireless communication apparatus according to claim 6, wherein a data rate is set based on an error rate that occurs.
A wireless communication device that performs co-channel transmission using orthogonal polarization signals,
An own polarization signal receiving means for receiving one of the transmitted polarization signals as an own polarization signal;
A cross-polarization signal receiving means for receiving a cross-polarization signal orthogonal to the self-polarization signal received by the self-polarization signal receiving means;
An inter-polarization interference compensation unit for compensating for the inter-polarization interference generated between the own-polarization signal received by the own-polarization signal receiving unit and the cross-polarization signal received by the cross-polarization signal receiving unit;
A wireless communication apparatus comprising: a transmission path state estimation unit that estimates a transmission path state based on a weighting factor used for compensating for the polarization interference by the interpolarization interference compensation unit.
A wireless communication method for performing co-channel transmission using orthogonal polarization signals,
Detecting an inter-polarization interference generated between a self-polarization signal that is one of the polarization signals and a cross-polarization signal orthogonal to the self-polarization signal;
A wireless communication method comprising: estimating a transmission path state based on the information related to the inter-polarization interference.
10. The wireless communication method according to claim 9, further comprising a step of setting a data rate according to a transmission path state estimated based on information on the inter-polarization interference.
Further comprising the step of controlling the received power of the polarization signal to converge to a predetermined power,
The radio communication method according to claim 10, wherein a data rate of the transmission signal is set based on the controlled power in addition to information on the interference between polarizations.
Further comprising the step of detecting an error rate generated in the own polarization signal from which the interference given by the cross polarization signal is removed from the own polarization signal,
The radio communication method according to claim 11, wherein a data rate of the transmission signal is set based on the error rate in addition to the information on the inter-polarization interference and the controlled power.
A non-transitory computer-readable medium storing a communication control program used in a wireless communication apparatus that performs co-channel transmission using orthogonal polarization signals,
Obtaining information relating to inter-polarization interference that occurs between a self-polarization signal that is one of the polarization signals and a cross-polarization signal that is orthogonal to the self-polarization signal;
Estimating a transmission path state based on information on the inter-polarization interference;
A step of setting a data rate of a transmission signal according to a transmission path state estimated based on the information on the interference between the polarizations, and a non-temporary storing a communication control program for causing a control computer of the wireless communication apparatus to execute Computer readable medium.