JP2007189306A - Device and system for radio communication - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio communication device that can use mutually orthogonal polarized waves simultaneously without using any mechanical drive type polarization separation circuits and has a high degree of freedom for the allocation of a frequency band to be used. <P>SOLUTION: The radio communication device receives a first multi-carrier signal that is transmitted by a first polarized wave, and includes a first unique word each; and a second multi-carrier signal that is transmitted by a second polarized wave orthogonal to the first one, and includes a second unique word each for demodulation. Therefore, the radio communication device comprises a first multi-carrier demodulation means for demodulating radio signals from the first reception antenna as first multi-carrier signals; a second multi-carrier demodulation means for demodulating radio signals from the second reception antenna as second multi-carrier signals; and an interference compensation means for calculating a propagation path matrix from the output signal of the first and second multi-carrier demodulation means and the first and second unique words, and for compensating the interference between both the polarized waves based on the propagation path matrix. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wireless communication apparatus and a wireless communication system that communicate with multi-polarized multi-carrier signals in order to improve frequency use efficiency in consideration of the convenience of users of the wireless communication apparatus.

  FIG. 8 is a diagram illustrating a frequency arrangement example of a wireless communication system using both vertical and horizontal polarizations. According to FIG. 8, in order to avoid mutual interference between polarized waves, the frequency band of each polarized wave is set in a staggered shape. In a wireless communication system such as a satellite communication system, a staggered arrangement as shown in FIG. 8 is generally used.

  In order to realize a staggered frequency arrangement, a filter is inserted in a radio communication apparatus such as a base station of a radio communication system or a relay station. In FIG. 8, an unused band is a band that is not currently used, but can be used as needed. A filter stop band is a stop band of a filter to be used, and C / N degradation is caused. Since it becomes prominent, it cannot be used for communication.

  FIG. 9 is a configuration diagram of a wireless communication system that uses two orthogonal polarizations. In FIG. 9, only the part which processes one polarization is shown. According to FIG. 9, the transmission station has a modulation circuit 41, a transmitter 42, and a transmission antenna 43, and the reception station has a reception antenna 44, a polarization separation circuit 45, and a demodulation circuit 46. is doing. The polarization separation circuit 45 includes a polarization axis control mechanism 451, a receiver 452, a selection circuit 453, and a polarization angle error detection circuit 454.

  In the transmission station, the modulation circuit 41 modulates the transmission signal, the transmitter 42 performs frequency conversion and amplification processing of the modulation signal, and the transmission antenna 43 transmits a radio signal of vertical or horizontal polarization.

  The radio signal transmitted from the transmission station rotates in the plane of propagation in the propagation process, and reaches the reception station as a radio signal including both vertical and horizontal polarization components. Therefore, in order to correctly demodulate the radio signal received at the receiving station, it is necessary to perform polarization separation.

  For this reason, the polarization separation circuit 45 of the receiving station selects only the polarization to be used among the radio signals received by the reception antenna 44, and the demodulation circuit 46 demodulates the modulation signal. In the polarization separation circuit 45, the polarization axis control mechanism 451 mechanically changes the polarization axis of the radio signal received by the receiving antenna 44 based on the error angle of the polarization axis detected by the polarization angle error detection circuit 454. The receiver 452 performs frequency conversion of each signal and the like, and the selection circuit 453 selects only the polarization signal to be used and demodulates the signal. The polarization angle error detection circuit 454 detects the error angle of the polarization axis by monitoring the output signal of the receiver 452, and outputs the detected error angle to the polarization axis control mechanism 451. The polarization separation circuit 45 is described in Non-Patent Document 1, for example.

  Regarding the adjustment of the polarization axis rotation, when the wireless communication apparatus is a mobile station, automatic control is required, but when the wireless communication apparatus is a fixed station, it can also be adjusted manually.

  As another form of the conventional wireless communication system, there is one that uses only one polarization and avoids inter-polarization interference by not using the other polarization in the same frequency band. In this mode, since only one polarization signal exists, if the reception power deterioration due to polarization rotation is allowed, the signal can be demodulated at the receiving station without performing polarization separation. It is not necessary to mount the polarization separation circuit 45, and the device cost can be reduced.

  Note that there are Non-Patent Document 2 related to compensation for interference based on ZF algorithm and MMSE algorithm and Patent Document 1 related to multicarrier modulation / demodulation as documents related to the present application.

Japanese Patent No. 3299952 Sekine Nobuyuki, “SNG Mobile Communication Receiving System”, Broadcast Technology, October 1994, pp. 140-pp. 144 Daikyo et al., “Space Division Multiplexing in MIMO Channel and Its Basic Characteristics”, IEICE Transactions B, Vol. J87-b No. 9, pp. 1162-1173, September 2004

  In the mechanically driven polarization separation circuit 45 described in Non-Patent Document 1, the circuit scale and weight of the wireless communication device are increased, and the control is complicated, so that the device cost of the wireless communication device increases. A method of performing inter-polarization interference compensation inside the demodulation circuit 46 without using the polarization separation circuit 45 is also conceivable. However, in this method, the maximum bandwidth that can be allocated to the radio communication apparatus is not used for both polarizations. Is limited to a certain band. For example, as shown in FIG. 10, when the bands 50 and 51 are already assigned to other wireless communication apparatuses, the new wireless communication apparatuses have bands 52 and 53 that are not used in common for both polarizations. However, in addition to the bands 52 and 53, the new wireless communication apparatus uses an unused band existing on the right side of the band 52, an unused band existing on the left side of the band 51, and the like. It is not possible.

  In another configuration in which the polarization separation circuit 45 is not mounted on the wireless communication device, other polarization is used to ensure the wireless communication quality in the band allocated to the wireless communication device not mounted with the polarization separation circuit 45. As a matter of course, it is desirable to prevent the interference from other polarizations from being mixed, but in this configuration, the frequency utilization efficiency of the entire wireless communication system is lowered. For example, as shown in FIG. 11, when the bands 50, 51, and 52 are already assigned to other wireless communication devices, the polarization separation circuit 45 is not mounted and the wireless communication device using only horizontal polarization is used. When the band 53 is allocated, the band on the right side of the band 51 and the band on the left side of the band 52 cannot be used.

  Therefore, the present invention can use the orthogonally polarized waves at the same time without using the mechanically driven polarization separation circuit 45 and has a high degree of freedom in assigning the frequency band to be used, and the wireless communication. The purpose is to provide a system.

According to the wireless communication device of the present invention,
A first multi-carrier radio signal that is transmitted from a transmitting station in a first polarization and that is composed of one or more independent carrier signals each including a first unique word; Receive and demodulate a second multi-carrier radio signal that is transmitted in a second polarization orthogonal to the polarization, each comprising one or more independent carrier signals each containing a second unique word A first wireless communication apparatus for demodulating a wireless signal received by a first receiving antenna, a second receiving antenna, and a first receiving antenna as being a first multi-carrier wireless signal Carrier demodulating means, second multicarrier demodulating means for demodulating a radio signal received by the second receiving antenna as being a second multicarrier radio signal, and first multicarrier demodulating means A propagation path matrix is calculated from the output signal, the output signal of the second multicarrier demodulation means, the first unique word, and the second unique word, and interference between both polarizations is compensated based on the propagation path matrix. Interference compensation means.

According to another embodiment of the wireless communication device of the present invention,
The interference compensation means includes a first matched filter for detecting the correlation between the output signal of the first multicarrier demodulation means and the first unique word, the output signal of the first multicarrier demodulation means and the second unique word. A second matched filter that detects a correlation between the second multi-carrier demodulating means, a third matched filter that detects a correlation between the output signal of the second multi-carrier demodulating means and the first unique word, and a second multi-carrier demodulating means A fourth matched filter that detects the correlation between the output signal and the second unique word, and outputs each of the matched filters at the time of detecting the correlation between the first and second unique words to the propagation path matrix. It is also preferable to use each propagation path matrix component.

According to another embodiment of the wireless communication device of the present invention,
It is also preferable that at least one carrier signal of the first multicarrier radio signal and the second multicarrier radio signal is a carrier signal in the same frequency band.

According to the wireless communication system of the present invention,
A wireless communication system having a transmitting station and a receiving station, wherein the transmitting station separates a transmission information sequence to be transmitted into a first information sequence and a second information sequence, and a first information sequence Multi-carrier modulation with one or more independent carrier signals, and a first multi-carrier modulation means for inserting a first unique word into an information sequence carried by each carrier signal, and a second information sequence, Second multi-carrier modulation means for multi-carrier modulation with one or more independent carrier signals and inserting a second unique word into the information sequence carried by each carrier signal; and the output of the first multi-carrier modulation means Means for transmitting a signal as a first multi-carrier radio signal by means of a first polarization, and a second multi-carrier modulation means for outputting an output signal orthogonal to the first polarization. Means for transmitting as a second multi-carrier radio signal by means of a wave, and the receiving station receives a first reception antenna, a second reception antenna, and a radio signal received by the first reception antenna as a first First multi-carrier demodulating means for demodulating as a multi-carrier radio signal and a second multi-carrier demodulating a radio signal received by the second receiving antenna as being a second multi-carrier radio signal A propagation path matrix is calculated from the demodulation means, the output signal of the first multicarrier demodulation means, the output signal of the second multicarrier demodulation means, the first unique word, and the second unique word, and propagated. Transmission information includes interference compensation means for compensating for interference between both polarizations based on a path matrix, and outputting a first information sequence and a second information sequence, and a first information sequence and a second information sequence. Parallel-serial conversion means for outputting a sequence, and determining carrier signals to be used for the first multi-carrier radio signal and the second multi-carrier radio signal based on propagation path information between the transmitting station and the receiving station. Features.

According to another embodiment of the wireless communication system of the present invention,
It is also preferable that the transmitting station determines a carrier signal to be used for the first multicarrier radio signal and the second multicarrier radio signal based on propagation path information between the transmitting station and the receiving station.

According to another embodiment of the wireless communication system of the present invention,
It is also preferable to use the frequency characteristics of the repeater existing between the transmitting station and the receiving station as the propagation path information.

Furthermore, according to another embodiment of the wireless communication system of the present invention,
It is also preferable that the receiving station has an interference power detection means for detecting the interference power, uses the interference power as propagation path information, and preferentially determines a carrier signal to be used from a frequency band with a small interference power.

Furthermore, according to another embodiment of the wireless communication system of the present invention,
The receiving station has delay dispersion detecting means for detecting delay dispersion, uses delay dispersion as propagation path information, and when the delay dispersion is equal to or greater than a preset threshold, the bandwidth of the carrier signal to be used It is also preferable to increase the number of carrier signals used.

Furthermore, according to another embodiment of the wireless communication system of the present invention,
It is also preferable that at least one carrier signal of the first multicarrier radio signal and the second multicarrier radio signal is a carrier signal in the same frequency band.

  Without using a conventional mechanically driven polarization separation circuit, it is possible to use both polarizations orthogonal to each other in the same frequency band, thereby reducing the cost of the wireless communication apparatus. Furthermore, the frequency utilization efficiency can be improved by dividing the necessary band into a plurality of bands and distributing the divided bands to the vacant frequencies of both orthogonal polarizations.

  By using in order from the band with the smallest interference power, the transmission capacity of the entire system can be expanded.

  Also, by reducing the bandwidth of the carrier signal used when there is a delayed wave, the error rate due to the delayed wave is prevented from increasing, and when there is no delayed wave, the bandwidth of the carrier signal is increased. The synchronization establishment time can be shortened.

  The best mode for carrying out the present invention will be described in detail below with reference to the drawings. In the following description, vertical polarization and horizontal polarization are used as the polarizations orthogonal to each other. However, the present invention applies polarizations orthogonal to each other, such as right-handed and left-handed circularly polarized waves. Applicable to all waves.

  FIG. 1 is a functional block diagram of a wireless communication apparatus constituting a wireless communication system according to the present invention. FIG. 1 (a) shows a transmitting station, (b) shows a receiving station, and (c) shows a relay station. Yes. According to FIG. 1, the transmitting station includes a serial-parallel conversion circuit 11, multicarrier modulation circuits 121 and 122, a transmitter 13, and transmitting antennas 141 and 142, and the receiving station receives receiving antennas 241 and 242. A receiver 23, multicarrier demodulation circuits 221 and 222, an interference compensation circuit 25, a parallel-serial conversion circuit 21, a delay dispersion detection circuit 26, and an interference power detection circuit 27. Receiving antennas 341 and 342, transmitting antennas 343 and 344, and a repeater 33.

  The wireless communication apparatus according to the present invention transmits an information sequence using one or more independent carrier signals for each of vertical polarization and horizontal polarization. The frequency band used here, that is, the carrier signal is determined based on propagation path information between the transmitting station and the receiving station. The propagation path information, as shown in FIG. 8, is information on the filter characteristics of a repeater existing between the transmitting station and the receiving station, interference power described later, and delay dispersion information. The carrier signal to be used is determined so that one carrier signal has the same frequency band in both polarizations. In this embodiment, the frequency band to be used is determined by a control unit (not shown) of the transmitting station. For this reason, the filter characteristic of the repeater is set in advance in a control unit (not shown) of the transmission station, and information on interference power and delay dispersion described later is acquired from the reception station by the control unit (not shown) of the transmission station. Also, one or more independent carrier signals means that each carrier signal is modulated independently.

  In the following description, it is assumed that the carrier signal output from the multicarrier modulation circuit 121 is transmitted with vertical polarization, and the carrier signal output from the multicarrier modulation circuit 122 is transmitted with horizontal polarization. For this reason, the transmitting antenna 141 of the transmitting station and the transmitting antenna 343 of the relay station are installed so as to be suitable for transmission of vertical polarization, and the transmitting antenna 142 of the transmitting station and the transmitting antenna 344 of the relay station are horizontally polarized. It is installed so as to be suitable for delivery. The receiving antenna 241 of the receiving station and the receiving antenna 341 of the relay station are installed so as to be suitable for reception of vertical polarization, and the receiving antenna 242 of the receiving station and the receiving antenna 342 of the relay station receive horizontal polarization. It is installed so as to be suitable for. In this specification, the term “multicarrier” includes a case where there is one carrier signal.

  The serial / parallel conversion circuit 11 of the transmitting station distributes the transmission information sequence into two information sequences and inputs them to the multicarrier modulation circuits 121 and 122, respectively. The multi-carrier modulation circuit 121 multi-carrier-modulates the input information series so as to become a signal in a frequency band determined for vertical polarization. At this time, the multicarrier modulation circuit 121 inserts a unique word into the information series carried by each carrier signal. Similarly, the multi-carrier modulation circuit 122 multi-carrier-modulates the input information series so as to become a signal in a frequency band determined for horizontal polarization. At this time, the multi-carrier modulation circuit 122 inserts a unique word into the information series carried by each carrier signal.

  The transmitter 13 performs frequency conversion and amplification of the signals output from the multicarrier modulation circuits 121 and 122, and the transmission antenna 141 performs vertical modulation on the signal modulated by the multicarrier modulation circuit 121 and processed by the transmitter 13. The transmission antenna 142 transmits the signal modulated by the multicarrier modulation circuit 122 and processed by the transmitter 13 as a horizontally polarized radio signal.

  The relay station is installed in the propagation path between the transmitting station and the receiving station as necessary, and the repeater 33 performs relay processing such as frequency conversion, filtering, and amplification on the radio signal received by the receiving antenna 341. And output to the transmission antenna 343. Here, for filtering the radio signal received by the receiving antenna 341, for example, a filter having a filter characteristic used for vertical polarization as shown in FIG. 8A is used. The repeater 33 performs relay processing such as frequency conversion, filtering, and amplification on the radio signal received by the reception antenna 342 and outputs the result to the transmission antenna 344. Here, for filtering the radio signal received by the receiving antenna 342, for example, a filter having a filter characteristic used for horizontal polarization as shown in FIG. 8B is used. The transmission antenna 343 transmits the signal received by the reception antenna 341 and relayed by the relay 33 as a vertically polarized radio signal, and the transmission antenna 344 is received by the reception antenna 342 and relayed by the relay 33. Is transmitted as a horizontally polarized radio signal.

  When the relay station is installed, the reception antenna 241 of the reception station transmits signals transmitted from the transmission antennas 343 and 344 of the relay station, and when the relay station is not installed, the transmission antenna 141 of the transmission station. And 142 receive the signal transmitted and output it to the receiver 23. Similarly, when the relay station is installed, the reception antenna 242 of the reception station transmits the signal transmitted by the transmission antennas 343 and 344 of the relay station, and when the relay station is not installed, Signals transmitted by the transmission antennas 141 and 142 are received and output to the receiver 23.

  The receiver 23 performs amplification and frequency conversion on the reception signals input to the reception antenna 241 and the reception antenna 242, and then receives the reception signal from the reception antenna 241 to the multicarrier demodulation circuit 221 and receives from the reception antenna 242. The signal is output to multicarrier demodulation circuit 222.

  The multicarrier demodulation circuit 221 demodulates the multicarrier signal used in vertical polarization and outputs it to the interference compensation circuit 25. The multicarrier demodulation circuit 222 demodulates the multicarrier signal used in horizontal polarization. And output to the interference compensation circuit 25.

  The interference compensation circuit 25 separates the inter-polarization interference for the reception signals input from the multicarrier demodulation circuit 221 and the multicarrier demodulation circuit 222 in units of vertical and horizontal polarization carrier signals in the same frequency band. FIG. 2 shows a functional block diagram of the interference compensation circuit 25.

  According to FIG. 2, the interference compensation circuit 25 includes a vertically polarized unique word matched filters 251 and 252, a horizontally polarized unique word matched filters 253 and 254, a power adding circuit 255, a threshold determining circuit 256, an interference And a compensation core circuit 257.

  The unique word matched filter 251 for vertically polarized waves is a unique word inserted by the multicarrier modulation circuit 121 of the transmitting station with respect to one carrier signal Y1 to be processed among the reception signals output from the multicarrier demodulation circuit 221. And the correlation value is output. Similarly, the horizontally polarized unique word matched filter 253 detects the correlation between one received carrier signal Y1 and the unique word inserted by the multicarrier modulation circuit 122 of the transmitting station, and outputs a correlation value. .

  The unique word matched filter 252 for vertical polarization is inserted by the multicarrier modulation circuit 121 of the transmitting station into one of the carrier signals Y2 to be processed among the reception signals output from the multicarrier demodulation circuit 222. The correlation with the unique word is detected and the correlation value is output. Similarly, the horizontally polarized unique word matched filter 254 detects the correlation of one received carrier signal Y2 with the unique word inserted by the multicarrier modulation circuit 122 of the transmitting station and outputs a correlation value. .

  The power addition circuit 255 adds the correlation results output by the unique word matched filters 251 and 252 for vertical polarization and the unique word matched filters 253 and 254 for horizontal polarization, and the threshold determination circuit 256 is output by the power addition circuit 255. The correlation value addition value is compared with a preset threshold value to determine the detection timing of each unique word. Since the correlation detection of the unique word can be detected in the same way with the power peak value or the voltage peak value, the power adding circuit 255 may be a simple voltage adding circuit (amplitude adding circuit).

The unique word matched filter 251 for vertical polarization, the unique word matched filter 253 for horizontal polarization, the unique word matched filter 252 for vertical polarization, and the unique word matched filter 254 for horizontal polarization at the timing when the unique word is detected. , Respectively, represent propagation path matrix components h ₁₁ , h ₁₂ , h ₂₁ , and h ₂₂ of the propagation path matrix. The interference compensation core circuit 257 removes the inter-polarization interference from the received signals Y1 and Y2 based on this propagation path matrix, and the information sequence X1 and the processing target transmitted by the vertical polarization among the carrier signals to be processed. Of the carrier signal, the information sequence X2 transmitted by horizontal polarization is restored and output. In order to restore the information sequences X1 and X2, a ZF algorithm, an MMSE algorithm, or the like is used.

  Note that the interference compensation circuit 25 shown in FIG. 2 is configured to process one set of vertical and horizontal polarizations in the same frequency band. In practice, the interference compensation circuit 25 corresponding to the number of carriers to be used is required. By applying time division digital signal processing, one interference compensation circuit 25 can be used for time division among a plurality of carrier signal sets, and the circuit can be reduced in size.

  The interference compensation circuit 25 eventually restores the input signal of the multi-carrier modulation circuit 121 and the input signal of the multi-carrier modulation circuit 122 of the transmitting station and outputs them to the parallel-serial conversion circuit 21. The parallel-serial conversion circuit 21 The two information series are parallel-serial converted, and the information series input to the transmitting station is restored and output.

  FIG. 4 is a diagram illustrating allocation of frequency bands to wireless communication apparatuses according to the present invention. When the required bandwidth W shown in FIG. 4 (a) is necessary for communication, the unused bandwidth is extracted in consideration of the frequency characteristics of each polarization, and the required bandwidth W is divided into multi-carriers and then allocated to the unused bandwidth. Do. Here, the dotted lines in FIGS. 4C and 4D indicate the assigned frequency bands. In the example of FIG. 4, the required bandwidth is divided into five from W1 to W5 as shown in FIG. 4 (b), and W1, W2, and W3 are respectively unused horizontal polarization bands shown in FIG. 4 (d). And W4 and W5 are assigned to unused vertical polarization bands shown in FIG.

  When the frequency allocation of FIG. 4 is performed, the multicarrier modulation circuit 121 is configured so that the signal after frequency conversion in the transmitter 13 is a signal in the frequency bands of W4 and W5 shown in FIG. The multi-carrier modulation is performed on the input information sequence, and the multi-carrier modulation circuit 122 is configured so that the signal after frequency conversion in the transmitter 13 is a signal in the frequency bands of W1, W2, and W3 shown in FIG. Multi-carrier modulation of the input information sequence.

  Here, W1 and W4 are different polarization signals in the same frequency band, and W3 and W5 are also different polarization signals in the same frequency band. Therefore, for W1 and W4 and W3 and W5, interference compensation between polarized waves is performed by the interference compensation circuit 25 of the receiving station. On the other hand, since W2 is only horizontal polarization, the interference compensation circuit 25 of the receiving station compensates only for polarization rotation. Therefore, good C / N characteristics can be obtained for W2.

  As described above, in the interference compensation circuit 25 of the receiving station, even when both polarized waves in the same frequency band are used or when one of the polarized waves is used, the inter-polarized wave interference is ideal. It is possible to restore the state where there is no.

  FIG. 5 is a diagram showing a comparison between the frequency band allocation according to the present invention and the frequency band allocation according to the prior art, and shows an example of the frequency allocation allocated to the vertical / horizontal polarization of the current satellite system. In the frequency arrangement of FIG. 5, the center frequency interval of each transponder is 30 MHz, and a frequency band of 27 MHz can be used in each transponder.

  As shown in FIG. 5 (a), in a conventional wireless communication apparatus that can use both polarized waves, when a vertical and horizontal band of 12 MHz is assigned to a certain wireless communication apparatus, a total of 24 MHz, the remaining bands are: Other wireless communication devices can be used, but the wireless communication device cannot be used.

  Further, as shown in FIG. 5B, when a 27 MHz band is allocated to the horizontally polarized wave to a wireless communication apparatus not equipped with the conventional polarization separation circuit 45 and the signal quality of the horizontally polarized wave is maintained, All wireless communication apparatuses cannot use the polarization band.

  On the other hand, as shown in FIG. 5 (c), in the wireless communication device according to the present invention, a maximum bandwidth of 54 MHz can be allocated to one wireless communication device. The bandwidth used by the device is approximately doubled, and the bandwidth usage of other wireless communication devices is not restricted, so that the frequency bandwidth can be used effectively.

  Since the wireless communication apparatus according to the present invention can allocate a wide band carrier signal to a continuous free band, it is not necessary to fill all the free bands with a plurality of narrow band carrier signals. As a result, there is an advantage that an increase in synchronization pull-in time, which is a problem with a narrow-band carrier signal, is avoided. Further, since the interference compensation circuit 25 can be easily realized by digital signal processing, it can be realized by a small component such as FPGA or LSI. Therefore, it is possible to use both polarizations in a low-cost wireless communication apparatus without using a mechanically driven polarization separation circuit as used conventionally. Furthermore, the use of digital signal processing has the advantage of superior temperature characteristics and aging degradation characteristics compared to mechanical driving.

  Next, frequency band allocation when there is interference will be described. In a multi-beam system using the same frequency, interference from other beams occurs within the use frequency. For example, in the multi-beam system shown in FIG. 6B, when attention is paid to the area indicated by A, interference from the area indicated by D using the same frequency band as A occurs. In such a situation, in FIG. 6A, interference as indicated by reference numeral 60 is observed in the wireless communication device in the area indicated by A. In this case, the interference power detection circuit 27 of the wireless communication apparatus detects the interference power and, for example, uses the frequency band preferentially from the frequency band with the small interference power, such as using the power sequentially from the band with the small interference power. By deciding and arranging the carrier signal, it is possible to construct a system that reduces deterioration of signal quality due to interference. In FIG. 6A, a band indicated by reference numeral 54 is assigned.

  FIG. 3 is a functional block diagram of the interference power detection circuit 27. According to FIG. 3, the interference power detection circuit 27 includes filters 271-1 to 271-N, filters 272-1 to 272-M, and a power detection circuit 273. The filters 271-1 to 271-N are band-pass filters having different center frequencies, respectively, and the signals received by the reception antenna 241 output from the receiver 23 are input. The filters 272-1 to 272-M are respectively These are band-pass filters having different center frequencies, and a signal received by the receiving antenna 242 output from the receiver 23 is input.

  The power detection circuit 273 measures the frequency distribution of the interference power from the output signal of each filter, and notifies the transmitter station of the measured interference power. The transmitting station determines a carrier signal to be preferentially used from a frequency band having a small interference power.

  By setting the carrier arrangement of the multi-carrier modulation circuit to a band with a small interference power, the line quality is improved, and the effect of expanding the transmission capacity of the entire system can be expected.

  Finally, the delay dispersion detection circuit 26 of the wireless communication device will be described. FIG. 7 is a diagram showing the output of the power addition circuit 255 of the interference compensation circuit 25 separately for the case where there is a delay wave and the case where there is no delay wave. When there is no delay wave, as shown in FIG. 7A, one autocorrelation peak value is output at the timing when the unique word is received, and a small cross-correlation value is output at other timings. On the other hand, when there is a delayed wave due to the surrounding environment, such as the presence of multipath, as shown in FIG. 7B, peak values of autocorrelation are observed at a plurality of timings. When transmitting a normal modulation signal, if the delay dispersion value is relatively larger than the symbol interval, the delayed wave is regarded as an interference component and the BER characteristic is deteriorated. For this reason, if the delay dispersion observed by the delay dispersion detection circuit 26 is larger than a threshold value set in advance according to the symbol interval, this information is fed back from the receiving station to the transmitting station, and the transmitting station uses the carrier signal to be used. The number of multicarriers is increased by narrowing the bandwidth per carrier. Thereby, the symbol interval of each carrier signal can be increased, and the deterioration of the BER characteristic due to the delayed wave can be alleviated while maintaining the transmission speed.

  As described above, the radio communication system according to the present invention has few restrictions on the frequency band to be used, and can use both polarized waves in the same frequency band at the same time, so that the frequency utilization efficiency can be improved. In particular, the frequency characteristic of the repeater is staggered and is suitable for a satellite communication system.

  In the embodiment described above, the transmission station determines the carrier signal to be used based on the propagation path information. The structure which notifies may be sufficient.

It is a functional block diagram of the radio | wireless communication apparatus by this invention. It is a functional block diagram of an interference detection circuit. It is a functional block diagram of an interference power detection circuit. It is a figure which shows allocation of the frequency band to the radio | wireless communication apparatus by this invention. It is a figure which shows the comparison of the frequency band allocation by this invention, and the frequency band allocation by a prior art. It is a figure explaining existence of an interference wave in a use frequency band. It is the figure which divided and showed the output of the electric power addition circuit in an interference compensation circuit, when a delay wave exists and when it does not exist. It is a figure which shows the example of a frequency arrangement | positioning of the radio | wireless communications system which uses both vertical and horizontal polarization. It is a figure which shows the block diagram of the conventional radio | wireless communications system. It is a figure which shows the form of the frequency allocation in the conventional radio | wireless communications system. It is a figure which shows the other form of the frequency allocation in the conventional radio | wireless communications system.

Explanation of symbols

11 Serial-parallel conversion circuit 121, 122 Multi-carrier modulation circuit 13, 42 Transmitter 141, 142, 343, 344, 43 Transmitting antenna 21 Parallel-serial conversion circuit 221, 222 Multi-carrier demodulation circuit 23, 452 Receiver 241, 242, 341 , 342, 44 Receiving antenna 25 Interference detection circuit 251, 252 Vertical polarization unique word matched filter 253, 254 Horizontal polarization unique word matched filter 255 Power addition circuit 256 Threshold decision circuit 257 Interference compensation core circuit 26 Delay dispersion detection circuit 27 Interference power detection circuit 271-1 to 271-N, 272-1 to 272-M Filter 273 Power detection circuit 33 Repeater 41 Modulation circuit 45 Polarization separation circuit 46 Demodulation circuit 451 Polarization axis control mechanism 453 Selection circuit 454 Bias Wave angle error detection Output circuit 51, 52, 53, 54 Band 60 Interference power

Claims (9)

A first multi-carrier radio signal transmitted from a transmitting station in a first polarization, each composed of one or more independent carrier signals including a first unique word;
A second multi-carrier radio signal transmitted from the transmitting station with a second polarization orthogonal to the first polarization, each composed of one or more independent carrier signals including a second unique word When,
A wireless communication device that receives and demodulates
A first receiving antenna, a second receiving antenna,
First multicarrier demodulation means for demodulating a radio signal received by the first receiving antenna as being a first multicarrier radio signal;
Second multicarrier demodulation means for demodulating a radio signal received by the second receiving antenna as being a second multicarrier radio signal;
A propagation path matrix is calculated from the output signal of the first multicarrier demodulation means, the output signal of the second multicarrier demodulation means, the first unique word, and the second unique word, and based on the propagation path matrix Interference compensation means for compensating for interference between both polarizations;
A wireless communication apparatus comprising: Interference compensation means
A first matched filter for detecting a correlation between the output signal of the first multi-carrier demodulating means and the first unique word;
A second matched filter for detecting a correlation between the output signal of the first multicarrier demodulating means and the second unique word;
A third matched filter for detecting a correlation between the output signal of the second multicarrier demodulating means and the first unique word;
A fourth matched filter for detecting a correlation between the output signal of the second multicarrier demodulating means and the second unique word;
Have
Making each output of each matched filter at the time of detecting correlation with the first and second unique words be each propagation path matrix component of the propagation path matrix,
The wireless communication apparatus according to claim 1. At least one carrier signal of the first multicarrier radio signal and the second multicarrier radio signal is a carrier signal in the same frequency band;
The wireless communication device according to claim 1, wherein the wireless communication device is a wireless communication device. A wireless communication system having a transmitting station and a receiving station,
The transmitting station is
A serial-parallel conversion means for separating a transmission information sequence to be transmitted into a first information sequence and a second information sequence;
Multi-carrier modulation of the first information sequence with one or more independent carrier signals, and first multi-carrier modulation means for inserting a first unique word into the information sequence carried by each carrier signal;
A second multi-carrier modulation means for multi-carrier modulating the second information sequence with one or more independent carrier signals and inserting a second unique word into the information sequence carried by each carrier signal;
Means for transmitting the output signal of the first multi-carrier modulation means as a first multi-carrier radio signal with a first polarization;
Means for transmitting the output signal of the second multicarrier modulation means as a second multicarrier radio signal by means of a second polarization orthogonal to the first polarization;
Have
The receiving station
A first receiving antenna, a second receiving antenna,
First multicarrier demodulation means for demodulating a radio signal received by the first receiving antenna as being a first multicarrier radio signal;
Second multicarrier demodulation means for demodulating a radio signal received by the second receiving antenna as being a second multicarrier radio signal;
A propagation path matrix is calculated from the output signal of the first multicarrier demodulation means, the output signal of the second multicarrier demodulation means, the first unique word, and the second unique word, and based on the propagation path matrix Interference compensation means for compensating for interference between both polarizations and outputting a first information sequence and a second information sequence;
A parallel-serial conversion means for outputting a transmission information sequence from the first information sequence and the second information sequence;
Have
Determining a carrier signal to be used for the first multi-carrier radio signal and the second multi-carrier radio signal based on propagation path information between the transmitting station and the receiving station;
A wireless communication system. The transmitting station determines a carrier signal to be used for the first multi-carrier radio signal and the second multi-carrier radio signal based on propagation path information between the transmitting station and the receiving station;
The wireless communication system according to claim 4. Use the frequency characteristics of the repeater that exists between the transmitting station and the receiving station as propagation path information,
The wireless communication system according to claim 4 or 5, wherein The receiving station has interference power detection means for detecting interference power,
Using interference power as propagation path information, preferentially determining a carrier signal to be used from a frequency band with low interference power,
The wireless communication system according to any one of claims 4 to 6. The receiving station has delay dispersion detecting means for detecting delay dispersion,
When delay dispersion is used as propagation path information and the delay dispersion is equal to or greater than a preset threshold, the bandwidth of the carrier signal to be used is narrowed and the number of carrier signals to be used is increased.
The wireless communication system according to any one of claims 4 to 7. At least one carrier signal of the first multicarrier radio signal and the second multicarrier radio signal is a carrier signal in the same frequency band;
The wireless communication system according to any one of claims 4 to 8.

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