Data communication device, data communication method, and data communication program

Abstract

This helps prevent data errors caused by interference between multiple radio signals with different polarizations. [Solution] The data communication device according to the present disclosure includes: a first receiving device that receives a first radio signal of a first frequency transmitted with polarization in a first direction and a second radio signal of a second frequency transmitted with polarization in a second direction, with polarization in a third direction, and generates a first received signal; a second receiving device that receives the first radio signal and the second radio signal with polarization in a fourth direction, and generates a second received signal; a first error detection device that generates a first error signal indicating the error between a first reference signal point indicating the reference of the signal point of the symbol of the first data in the first received signal and a first signal point of the symbol of the first data demodulated from the first received signal; and a first error removal device that removes errors from the first received signal based on the first error signal and the second received signal.

Description

[Technical Field]

[0001] This disclosure relates to a data communication device, a data communication method, and a data communication program. [Background technology]

[0002] A method is known in which a radio signal modulated by data is transmitted at the transmitting end through multiple antennas with different polarization directions, and the transmitted radio signal is received at the receiving end through multiple antennas with different polarization directions. Another method is known in which a radio signal of multiple frequencies is transmitted at the transmitting end, each modulated by one of multiple types of data, and the transmitted radio signal of multiple frequencies is received at the receiving end. For example, Patent Document 1 discloses a method in which a radio signal of two different frequencies is transmitted at the transmitting end through two antennas with orthogonal polarization. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-161731 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] The disclosures in the above prior art documents are incorporated into this document by reference. The following analysis was performed by the inventors.

[0005] However, the method disclosed in Patent Document 1 does not take measures to address data errors caused by interference between orthogonal polarized radio signals when the receiving side receives the radio signal via two antennas with orthogonal polarization and demodulates the data.

[0006] The purpose of this disclosure is, in light of the aforementioned problems, to contribute to preventing data errors caused by interference between multiple radio signals with different polarizations when receiving and demodulating data from multiple radio signals with different polarizations. [Means for solving the problem]

[0007] In a first aspect of this disclosure, a data communication device is provided. This data communication device includes: a first receiving device that receives a first radio signal of a first frequency, including a symbol of first data, transmitted with polarization in a first direction, and a second radio signal of a second frequency, including a symbol of second data, transmitted with polarization in a second direction different from the first direction, with polarization in a third direction to generate a first received signal; a second receiving device that receives the first radio signal and the second radio signal with polarization in a fourth direction different from the third direction to generate a second received signal; a first error detection device that generates a first error signal indicating the error between a first reference signal point indicating a reference for the signal point of the symbol of first data in the first received signal and a first signal point of the symbol of first data demodulated from the first received signal; and a first error removal device that removes an error from the first received signal based on the first error signal and the second received signal.

[0008] A second aspect of this disclosure provides a data communication method. This data communication method generates a first received signal by receiving a first radio signal of a first frequency, which includes a symbol of first data and is transmitted with polarization in a first direction, and a second radio signal of a second frequency, which includes a symbol of second data and is transmitted with polarization in a second direction different from the first direction, with polarization in a third direction; generates a second received signal by receiving the first radio signal and the second radio signal with polarization in a fourth direction different from the third direction; and the received first received signal and the second received signal A data communication method comprising: generating a first combined signal by combining a first received signal and a second received signal; generating a second combined signal by combining the received first received signal and the second received signal; generating a first error signal indicating the error between a first reference signal point indicating a reference for the signal point of the symbol of the first data in the first received signal and a first signal point of the symbol of the first data demodulated from the first combined signal; and removing errors from the first combined signal based on the first error signal and the second combined signal.

[0009] A third perspective of this disclosure provides a data communication program. This data communication program includes a process of generating a first received signal by receiving a first radio signal of a first frequency, which includes a symbol of first data and is transmitted with polarization in a first direction, and a second radio signal of a second frequency, which includes a symbol of second data and is transmitted with polarization in a second direction different from the first direction, with polarization in a third direction; a process of generating a second received signal by receiving the first radio signal and the second radio signal with polarization in a fourth direction different from the third direction; and the received first received signal and the second received signal The processor is made to perform the following processes: a process of synthesizing to generate a first composite signal; a process of synthesizing the received first received signal and the second received signal to generate a second composite signal; a process of generating a first reference signal point indicating the reference of the signal point of the symbol of the first data in the first received signal and a first error signal indicating the error between the first signal point of the symbol of the first data demodulated from the first composite signal; and a process of removing errors from the first composite signal based on the first error signal and the second composite signal. This program can be recorded on a computer-readable storage medium. The storage medium may be a non-transitory medium such as semiconductor memory, hard disk, magnetic recording medium, or optical recording medium. This disclosure can be embodied as a computer program product. [Effects of the Invention]

[0010] From each perspective of this disclosure, when receiving multiple radio signals with different polarizations and demodulating the data, it is possible to help prevent data errors caused by interference between multiple radio signals with different polarizations. [Brief explanation of the drawing]

[0011] [Figure 1A] Figure 1A is a diagram illustrating an example of the configuration of a data transmission and reception system according to one embodiment of the present disclosure. [Figure 1B] Figure 1B is a diagram illustrating an example configuration of the data communication system shown in Figure 1A. [Figure 1C] FIG. 1C is a diagram illustrating a configuration example of the error removal device shown in FIG. 1B. [Figure 1D] FIG. 1D is a diagram illustrating an exemplary process of subtracting an error removal signal from a composite signal by the error removal devices shown in FIGS. 1B and 1C. [Figure 1E] FIG. 1E is a diagram illustrating signal points of symbols of transmission data in a composite signal when only affected by an error radio wave signal. [Figure 1F] FIG. 1F is a diagram illustrating signal points of symbols of transmission data V in a composite signal V when affected by disturbances such as an error radio wave signal and other noise signals. [Figure 1G] FIG. 1G is a diagram illustrating a configuration example of an arithmetic processing unit that executes instruction commands included in one or more programs for realizing functions of components of a data transmission / reception system. [Figure 2] FIG. 2 is a flowchart illustrating an operation example of the data transmission / reception system shown in FIG. 1 and the like. [Figure 3A] FIG. 3A is a diagram illustrating an exemplary normal operation of a data transmission / reception system. [Figure 3B] FIG. 3B is a diagram illustrating an exemplary normal operation when diversity using frequency, vertical polarization, and horizontal polarization is not performed in a data transmission / reception system. [Figure 4A] FIG. 4A is a diagram illustrating an exemplary abnormal operation of a data transmission / reception system. [Figure 4B] FIG. 4B is a diagram illustrating an exemplary abnormal operation when diversity is not performed in a data transmission / reception system.

Embodiments for Carrying Out the Invention

[0012] Embodiments of this disclosure will be described below with reference to the drawings. However, this disclosure is not limited to the embodiments described below. In each drawing, the same or corresponding elements are appropriately denoted by the same reference numerals, and the same or corresponding processes and communications are appropriately denoted by the same reference numerals. Furthermore, it should be noted that the drawings are schematic and the dimensional relationships and proportions of each element may differ from reality. Also, the dimensional relationships and proportions may differ between drawings. In addition, the connecting lines between blocks such as drawings referred to in the following description include both bidirectional and unidirectional lines. Unidirectional arrows schematically indicate the flow of the main signal (data) and do not exclude bidirectionality. Furthermore, the direction of the antenna directivity may have an error within the tolerance range, the range recognized among those skilled in the art or the range that is technically permissible.

[0013] Figure 1A is a diagram illustrating an example configuration of a data transmission / reception system 1 according to one embodiment of the present disclosure. The data transmission / reception system 1 shown in Figure 1A comprises a transmitting system 10 and a receiving system 12 (data communication device). The transmitting system 10 comprises a data communication system 14-1, an antenna 14V-1 with polarization in the direction of vertical (first direction, third direction), and an antenna 14H-1 with polarization in the direction of horizontal (second direction, fourth direction). Hereinafter, "with polarization in the direction of vertical" will also be written as "vertically polarized," and "with polarization in the direction of horizontal" will also be written as "horizontally polarized." The receiving system 12 comprises a data communication system 14-2, a vertically polarized antenna 14V-2, and a horizontally polarized antenna 14H-2.

[0014] As will be described later with reference to Figures 1B, 1C, and 1G, data communication systems 14-1 and 14-2 have the same configuration and can operate in the same way, so data can be transmitted bidirectionally between data transmission and reception system 1 and data communication systems 14-1 and 14-2. However, in the following description, in order to clarify and concretize the explanation and facilitate understanding, the case in which data is transmitted from the transmitting system 10 to the receiving system 12 will be used as a specific example. Also, for the same reason, the number of polarization directions and frequencies that can be used in data transmission and reception system 1 is not limited to two, but may be three or more, however, in the following explanation, the case in which the polarization directions are vertical and horizontal and the number of frequencies is two will be used as a specific example. The data transmission and reception system 1 transmits transmission data V and H (first data and second data) from the transmitting system 10 to the receiving system 12 using diversity with two frequencies f1 and f2 (first frequency and second frequency) and two different polarizations (vertical polarization and horizontal polarization).

[0015] Furthermore, in the data transmission / reception system 1, a transmission signal is obtained by modulating the carrier signal with data using a digital modulation scheme, and this transmission signal is transmitted as a radio wave signal. A received signal is obtained by receiving the transmitted radio wave signal, the carrier signal is reconstructed from the received signal, and the data is demodulated. In the data transmission / reception system 1, various modulation schemes such as QPSK (Quadrature Phase Shift Keying), 64QAM (64 Quadrature Amplitude Modulation), and OFDM (Orthogonal Frequency Division Multiplexing) can be used for digital modulation. For the reasons mentioned above, a specific example in the data transmission / reception system 1 is the transmission and reception of a radio wave signal modulated by QPSK. Prior to data transmission, all information that should be prerequisites for data transmission, such as the fact that the data is modulated and demodulated in accordance with QPSK, and the frequency of the clock signal used for data modulation and demodulation, is commonly set in the data communication systems 14-1 and 14-2.

[0016] In the data transmission and reception system 1, the data communication system 14-1 and antenna 14V-1 of the transmitting system 10 transmit transmission signals Vf1 and Vf2 with frequencies f1 and f2 modulated by transmission data V received from a data processing device and data communication network (not shown) connected to the transmitting system 10 as vertically polarized transmission radio signals Vf1 and Vf2 (first radio signals) to the receiving system 12. In addition, the data communication system 14-1 and antenna 14H-1 of the transmitting system 10 transmit transmission signals Hf1 and Hf2 with two frequencies f1 and f2 modulated by transmission data H received from a data processing device and the like as horizontally polarized transmission radio signals Hf1 and Hf2 (second radio signals) to the receiving system 12.

[0017] The vertically polarized antenna 14V-2 of the receiving system 12 receives the transmitted radio signals Vf1 and Vf2 from the transmitting system 10, and error radio signals H, which include a portion of the transmitted radio signals Hf1 and Hf2 that have been added to the transmitted radio signals Vf1 and Vf2 due to signal interference, and other noise radio signals, using the diversity method described above to generate the received signals Vf1 and Vf2. Similarly, the horizontally polarized antenna 14H-2 of the receiving system 12 receives the transmitted radio signals Hf1 and Hf2 from the transmitting system 10, and error radio signals V, which includes a portion of the transmitted radio signals Vf1 and Vf2 that have been added to the transmitted radio signals Hf1 and Hf2 due to signal interference, and other noise radio signals, using the diversity method described above to generate the received signals Vf1 and Vf2.

[0018] Furthermore, the data communication system 14-2 demodulates the received data V corresponding to the transmitted data V from the received signals Vf1 and Vf2 and outputs it to a data processing device connected to the receiving system 12. Similarly, the data communication system 14-2 demodulates the received data H corresponding to the transmitted data H from the received signals Hf1 and Hf2 and outputs it to a data processing device connected to the receiving system 12. Note that when no data errors occur in the received data V and H during data transmission in the data transmission system 1, the transmitted data V and the received data V corresponding to the transmitted data V will be the same, and the transmitted data H and the received data H corresponding to the transmitted data H will be the same.

[0019] Figure 1B illustrates an example configuration of the data communication systems 14-1 and 14-2 shown in Figure 1A. As shown in Figure 1B, the data communication systems 14-1 and 14-2 include a vertical polarization transmitting / receiving system 140V, a horizontal polarization transmitting / receiving system 140H, and a modulation / demodulation system 16. The vertical polarization transmitting / receiving system 140V includes transmitting devices 144Vf1 and 144Vf2, receiving devices 146Vf1 and 146Vf2 (first receiving devices), and a combining device 142V (first combining device). The horizontal polarization transmitting / receiving system 140H includes transmitting devices 144Hf1 and 144Hf2 and receiving devices 146Hf1 and 146Hf2 (second receiving devices). The horizontal polarization transmitting and receiving system 140H comprises transmitting devices 144Hf1, 144Hf2, receiving devices 146Hf1, 146Hf2, and combining device 142H (second combining device). The modulation and demodulation system 16 comprises demodulation and error detection devices 160V, 160H (first error detection device, second error detection device), modulation devices 162V, 162H, and error removal devices 18V, 18H (first error removal device, second error removal device).

[0020] Figure 1C illustrates one example configuration of the error removal device 18V shown in Figure 1B. As shown in Figure 1C, the error removal device 18V comprises a subtraction circuit 180V, a filter coefficient generation circuit 182V, and a digital filter 184V. The digital filter 184V is, for example, a Finite Impulse Response (FIR) filter containing m taps (where m is an integer of 2 or more). The error removal device 18H comprises a subtraction circuit 180H, a filter coefficient generation circuit 182H, and a digital filter 184H (not shown in Figure 1C to avoid duplication) that perform the same operations as the subtraction circuit 180V, filter coefficient generation circuit 182V, and digital filter 184V of the error removal device 18V.

[0021] In the vertical polarization transceiver system 140V of the transmitting system 10, the transmitting devices 144Vf1 and Vf2 convert the intermediate frequency (IF) signal, which has been QPSK modulated by the transmission data V in the modulator 162V, into transmission signals Vf1 and Vf2 with frequencies f1 and f2, and transmit them to the receiving system 12 as transmitted radio signals Vf1 and Vf2 via the vertical polarization antenna 14V-1. The transmitting devices 144Hf1 and Hf2 convert the IF signal, which has been modulated by the transmission data H in the modulator 162H, into transmission signals Hf1 and Hf2 with frequencies f1 and f2, and transmit them to the receiving system 12 as transmitted radio signals Hf1 and Hf2 via the horizontal polarization antenna 14H-1.

[0022] In the vertical polarization transmitting / receiving system 140V of the receiving system 12, the receiving devices 146Vf1 and 146Vf2 receive vertically polarized transmitted radio signals Vf1 and Vf2 from the transmitting system 10 via the vertically polarized antenna 14V-2 and generate received signals Vf1 and Vf2 with frequencies f1 and f2. Furthermore, the receiving devices 146Vf1 and 146Vf2 convert the received signals Vf1 and Vf2 into IF signals of a predetermined frequency and output them to the combining device 142V. In addition, the receiving devices 146Vf1 and 146Vf2 may receive a portion of the transmitted radio signals Hf1 and Hf2 from the transmitting system 10 as interference signals, etc., via the antenna 14V-2. Therefore, the IF signal generated from the received signals Vf1 and Vf2 includes, in addition to the components of the transmitted radio signals Vf1 and Vf2, a portion of the transmitted signals Hf1 and Hf2 from the transmitting system 10 and other components such as noise radio waves as an error signal H (first error signal).

[0023] The combining device 142V adjusts the phase of the IF signal generated from the received signal Vf1 and the IF signal generated from the received signal Vf2 to synchronize them, adjusts their amplitudes to make them equal, and combines them by adding them together to obtain the gain from the combination. Furthermore, the combining device 142V outputs the combined signal V obtained by this combination to the error removal devices 18V and 18H of the modulation / demodulation system 16.

[0024] In the horizontal polarization transmitting / receiving system 140H of the receiving system 12, the receiving devices 146Hf1 and 146Hf2 receive the horizontally polarized transmitted radio signals Hf1 and Hf2 from the transmitting system 10 via the vertically polarized antenna 14H-2 and generate received signals Hf1 and Hf2 with frequencies f1 and f2. Furthermore, the receiving devices 146Hf1 and 146Hf2 convert the received signals Hf1 and Hf2 into IF signals of a predetermined frequency and output them to the combining device 142H. In addition, the receiving devices 146Hf1 and 146Hf2 may receive a portion of the transmitted radio signals Vf1 and Vf2 from the transmitting system 10 as interference signals, etc., via the antenna 14H-2. Therefore, the IF signals generated from the received signals Hf1 and Hf2 include, in addition to the components of the transmitted radio signals Hf1 and Hf2, a portion of the transmitted signals Vf1 and Vf2 from the transmitting system 10 and other components such as noise radio waves as an error signal V (second error signal). The combining device 142H adjusts the phase of the IF signal generated from the received signal Hf1 and the IF signal generated from the received signal Hf2 to synchronize them, adjusts their amplitudes to make them equal, and combines them by adding them together to obtain a gain from the combination. Furthermore, the combining device 142H outputs the combined signal H obtained by this combination to the error removal devices 18V and 18H of the modulation / demodulation system 16.

[0025] More specifically, the combining devices 142V and 142H include a clock regeneration circuit, a symbol timing synchronization circuit, and a phase error correction circuit (not shown). The clock regeneration circuit regenerates the clock signal used in the transmitting system 10 to modulate the IF signal with the transmission data V and H from the combined signal V and H (IF signal). The symbol timing synchronization circuit corrects the combined signal V and H (IF signal) using the regenerated clock signal and synchronizes the clock signal with the symbols of the transmission data V and H included in the combined signal V and H (IF signal). The phase error correction circuit detects the phase difference between the combined signal V and H (IF signal) and the clock signal, corrects the phase difference between these signals, and brings the phase difference closer to zero.

[0026] Furthermore, the demodulation / error detection device 160V detects the difference between the signal point (reference signal point) in the IQ plane of the symbol of the transmitted data V under conditions where the transmitted data V can be accurately decoded from the composite signal V, and the signal point in the IQ plane of the symbol of the transmitted data V actually decoded from the composite signal V. The demodulation / error detection device 160V outputs an error signal V indicating the detected difference to the error removal device 18V. The demodulation / error detection device 160V demodulates the received data V from the composite signal V from which the error signal V has been removed by the error removal device 18V, and outputs the demodulated received data V to a data processing device or the like. Furthermore, the demodulation / error detection device 160H outputs an error signal H indicating the difference between the reference signal point of the transmitted data H and the signal point of the actually decoded transmitted data H to the error removal device 18H. The demodulation and error detection device 160H demodulates the received data H from the composite signal V from which the error signal H has been removed by the error removal device 18H, and outputs the demodulated received data H to a data processing device or the like.

[0027] Figure 1D illustrates an example of a process in which the error removal device 18V shown in Figures 1B and 1C subtracts the error removal signal from the combined signal V. In the receiving system 12, the subtraction circuit 180V of the error removal device 18V removes the error component from the combined signal V, which is input to the positive (+) input terminal of the combined device 142V, by subtracting the error removal signal, which is input to the negative (-) input terminal of the digital filter 184V, from the combined signal V, as shown in Figure 1D. The subtraction circuit 180V outputs the combined signal V from which the error component has been removed to the demodulation / error detection device 160V. The digital filter 184V generates an error removal signal by filtering the combined signal H using the filter coefficients input from the filter coefficient generation circuit 182V, and outputs it to the negative (-) input terminal of the subtraction circuit 180V.

[0028] The filter coefficient generation circuit 182V processes the error signal V and the composite signal H input from the demodulation and error detection device 160V by using the least mean square (LMS) algorithm or the normalized least mean square (NLMS) algorithm, and adaptively optimizes and generates the filter coefficient W n+1 used in the digital filter 184V. However, when the digital filter 184V is a FIR filter including m taps as described above, the filter coefficient W i (where 1 ≦ i ≦ n + 1) corresponds to m elements w i,1 , w i,2 , ···, w i,m-1 , w i,m set for these m taps. Therefore, the filter coefficient Wi can be described in the form of a vector. That is, the filter coefficient W i =(w i,1 , w i,2 , ···, w i,m-1 , w i,m ). Note that all initial values w i of the m elements of the filter coefficient W 1,1 , w 1,2 , ···, w 1,m-1 , w 1,m are, for example, all 0. That is, the initial value of the filter coefficient W i described in the form of a vector is W1 = (0, 0, ···, 0).

[0029] For example, when the filter coefficient generation circuit 182V adaptively optimizes and generates the filter coefficient W n+1 by using the least mean square algorithm, the process shown in Equation 1 below is performed to generate an error removal signal. Note that the two terms on the right side of Equation 1 below correspond to the detection of the correlation between the composite signals V and H. For example, when interference of the composite signal V occurs in the composite signal H, this interference continues for a certain period of time and can be estimated. Therefore, the error caused by the interference from the composite signal H to the composite signal V can be gradually reflected in the composite signal V as the filter coefficient W1, and can be fed back after the next symbol of the composite signal V.

[0030] The composite signal V may contain superimposed errors, which are a combination of errors correlated with composite signal H due to interference from composite signal H and errors not correlated with composite signal H due to unknown noise randomly applied to the radio signal. Of the superimposed errors, the component of errors correlated with composite signal H can be extracted by correlating composite signal H with the superimposed errors. The extracted component of errors correlated with composite signal H can be removed from composite signal V. When the component of errors correlated with composite signal H is removed from composite signal V, the rate of data errors occurring in the data demodulated from composite signal V is kept low.

[0031] Furthermore, in Equation 1 below, the filter coefficient generation step μ is a value used to adjust the convergence speed and stability of the filter coefficient W1. When the value of the filter coefficient generation step μ is large, the convergence speed of the filter coefficient W1 increases but the stability of convergence decreases, and when the value of the filter coefficient generation step μ is small, the convergence speed of the filter coefficient W1 decreases but the stability of convergence increases. Thus, there is a trade-off relationship between the convergence speed and the stability of convergence of the filter coefficient W1. Therefore, the filter coefficient generation step μ can be determined, for example, by experiment or simulation, so that the convergence speed and stability of convergence of the filter coefficient W1 are within an appropriate range.

[0032]

number

[0033] The digital filter 184V produces the filter coefficients W in this manner. n+1 The combined signal H is filtered using this method to generate an error-removed signal. The subtraction circuit 180V subtracts the error-removed signal thus generated from the combined signal V to minimize the error component contained in the combined signal V.

[0034] Furthermore, the subtraction circuit 180H of the error removal device 18H, similar to the subtraction circuit 180V of the error removal device 18V, removes the error component from the combined signal H by subtracting the error removal signal input to the negative (-) input terminal of the digital filter 184H from the combined signal H input to the positive (+) input terminal of the combining device 142H. The subtraction circuit 180H outputs the combined signal H, from which the error component has been removed, to the demodulation / error detection device 160H. The digital filter 184H generates an error removal signal by filtering the combined signal H using the filter coefficients input from the filter coefficient generation circuit 182H, and outputs it to the negative (-) input terminal of the subtraction circuit 180H.

[0035] The filter coefficient generation circuit 182H performs the same process as the filter coefficient generation circuit 182V, referring to equation 1 above, and generates the filter coefficient W n+1 The filter coefficients W are generated by adaptive optimization. The digital filter 184H uses the filter coefficients W generated in this way. n+1 The combined signal V is filtered using this method to generate an error-removed signal. The subtraction circuit 180H subtracts the error-removed signal thus generated from the combined signal H to minimize the error component contained in the combined signal H.

[0036] Figure 1E illustrates the signal point of the symbol of the transmitted data V in the composite signal V when it is affected only by error radio signals Hf1 and Hf2. When the signal point of the symbol of the transmitted data V in the composite signal V is as shown by the symbol a in the IQ space shown in Figure 1E, the signal point of the symbol of the transmitted data V in the composite signal V when it is affected only by error radio signals Hf1 and Hf2 changes to, for example, the position shown by the symbol b in Figure 1E, and the error signal V input from the demodulation / error detection device 160V to the error removal device 18V becomes as shown by the symbol c in Figure 1E. As shown by the symbol d in Figure 1E, the error signal V is correlated with the composite signal V, so as shown by the symbol e in Figure 1E, the signal point of the symbol of the transmitted data V can be easily adjusted to the reference signal point by subtracting the error signal V from the signal point of the symbol of the transmitted data V.

[0037] Figure 1F illustrates the signal point of the symbol of the transmitted data V in the composite signal V when it is affected by disturbances such as error radio signals Hf1, Hf2 and other noise signals. When the signal point of the symbol of the transmitted data V in the composite signal V is as shown by the symbol a in the IQ space shown in Figure 1F, the signal point of the symbol of the transmitted data V in the composite signal V when it is affected by error radio signals Hf1, Hf2 and other disturbances changes to, for example, the position shown by the symbol b in Figure 1F. In such a case, the error signal V input from the demodulation / error detection device 160V to the error removal device 18V becomes as shown by the symbol c in Figure 1F.

[0038] As shown in Figure 1F, denoted by the symbol d, the error signal V includes components that correlate with the composite signal V and components that do not have correlation errors. Therefore, as shown in Figure 1F, denoted by the symbol e, simply subtracting the error signal V from the signal point of the symbol of the transmitted data V will not allow the signal point of the symbol of the transmitted data V to be aligned with the reference signal point. On the other hand, as explained with reference to Equation 1 above, if the filter coefficient generation circuit 182V is configured to generate adaptively optimized filter coefficients, an error-removed signal can be generated that aligns the signal point of the symbol of the transmitted data V to the reference signal point, even when the composite signal V is affected by error radio signals Hf1, Hf2 and other disturbances. Hereinafter, when describing any of the multiple components of the data transmission and reception system 1 without specifying one of them, such as "antenna 14V-1, 14V-2," the subscripts "V-1," "V-2," etc., may be omitted, and it may simply be described as "antenna 14," etc.

[0039] Except for components that must be made of hardware, such as the antenna 14, the functions, processing, and operation of the components of the data transmission and reception system 1 shown in Figures 1A to 1C can be implemented in software by executing instructions included in one or more programs. Figure 1G is a diagram illustrating one example of the configuration of the arithmetic processing unit 5 that executes instructions included in one or more programs that realize the functions of the components of the data transmission and reception system 1.

[0040] As shown in Figure 1G, the arithmetic processing unit 5 (computer) has a configuration in which a processor 500, main memory 502, auxiliary memory 504, interface (IF) device 506, analog-to-digital converter (A / D) 508, and digital-to-analog converter (D / A) 510 are connected to each other via a bus or the like so that they can communicate with one another. However, the configuration of the arithmetic processing unit 5 is not limited to the configuration shown in Figure 1G, and the arithmetic processing unit 5 may include many more components, or some of the components of the arithmetic processing unit 5 may be omitted as appropriate.

[0041] The processor 500 includes one or more of the following: CPU (Central Processing Unit), MPU (Micro Processing Unit), GPU (Graphics Processing Unit), DSP (Digital Signal Processor), and FPGA (Field Programmable Gate Array). The processor 500 executes instructions contained in one or more programs that realize the functions of the components of the data transmission and reception system 1 stored in the main memory 502. The main memory 502 includes memory elements such as ROM (Read Only Memory) and RAM (Random Access Memory) and stores one or more programs executed by the processor 500, and temporarily stores data used when the processor 500 executes one or more programs.

[0042] The auxiliary storage device 504 includes one or more non-transitory storage media and memory devices such as a CD drive, HDD (Hard Disk Drive), SSD (Solid State Drive), and flash memory. The auxiliary storage device 504 stores one or more programs executed by the processor 500, and data required when one or more programs are executed by the processor 500, in the non-transitory storage media and memory devices for medium-term or long-term storage. The auxiliary storage device 504 may also be used for updates and upgrades of one or more programs executed by the processor 500.

[0043] The interface device 506 connects the arithmetic processing unit 5 and the data processing unit connected to the data transmission / reception system 1, and performs the necessary processing to receive input data and output output data. The A / D 508 performs processing to convert analog signals to digital data, for example, by converting an analog received signal into digital data that can be processed by the arithmetic processing unit 5. The D / A 510 performs processing to convert digital data to analog signals, for example, by converting digital transmission data into an analog transmission signal.

[0044] The following describes an example of the operation of the data transmission and reception system 1 shown in Figures 1A to 1C. Figure 2 is a flowchart illustrating an example of the operation (S10) of the data transmission and reception system 1 shown in Figures 1A to 1C. As shown in Figures 1A to 1C, prior to the processing shown in Figure 2, the transmitting devices 144Vf1 and 144Vf2 of the data communication system 14-1 of the transmitting system 10 transmit vertically polarized radio signals Vf1 and Vf2 with frequencies f1 and f2 modulated by the transmission data V to the receiving system 12. In addition, the transmitting devices 144Hf1 and 144Hf2 of the transmitting system 10 transmit horizontally polarized radio signals Hf1 and Hf2 with frequencies f1 and f2 modulated by the transmission data V to the receiving system 12.

[0045] As shown in Figure 2, in S100, the receiving devices 146Vf1 and 146Vf2 of the receiving system 12 receive the transmitted radio signals Vf1 and Vf2 from the transmitting system 10 via the vertically polarized antenna 14V and generate received signals Vf1 and Vf2 with frequencies f1 and f2. Furthermore, the receiving devices 146Vf1 and 146Vf2 convert the received signals Vf1 and Vf2 into IF signals and output them to the combining device 142V. In addition, the receiving devices 146Hf1 and 146Hf2 receive the transmitted radio signals Hf1 and Hf2 from the transmitting system 10 via the vertically polarized antenna 14H and generate received signals Hf1 and Hf2 with frequencies f1 and f2. Furthermore, the receiving devices 146Hf1 and 146Hf2 convert the received signals Hf1 and Hf2 into IF signals and output them to the combining device 142H.

[0046] In S102, the combining device 142V combines the IF signals obtained from the received signals Vf1 and Vf2 to generate a combined signal V, which is output to the error removal device 18V. The combining device 142H also combines the IF signals obtained from the received signals Hf1 and Hf2 to generate a combined signal H, which is output to the error removal device 18H.

[0047] In S104, the clock regeneration circuit (not shown) of the combining device 142V regenerates the clock signal used for modulation in the modulator 162V of the transmitting system 10 from the combined signal V. The clock regeneration circuit of the error removal device 18H also regenerates the clock signal used for modulation in the modulator 162H of the transmitting system 10 from the combined signal H. Furthermore, using the regenerated clock signal, the timing of the symbols of the transmitted data V included in the combined signal V is regenerated from the combined signal V. Additionally, the timing synchronization circuit of the error removal device 18H uses the regenerated clock signal to regenerate the timing of the symbols of the transmitted data H included in the combined signal H from the combined signal H.

[0048] In S106, the timing synchronization circuits of the error removal devices 18V and 18H determine whether the timing of the symbols of the transmitted data V and H is synchronized with the clock signal. The receiving system 12 proceeds to operation S108 if the timing of both symbols of the transmitted data V and H is synchronized with the clock signal (Y in operation S106), and returns to operation S104 if they are not synchronized (N in operation S106).

[0049] In S108, the timing synchronization circuits of the error removal devices 18V and 18H detect the error between the phase of the carrier signal used in the transmitting system 10 and the phase of the carrier signal used in the receiving system 12. Furthermore, the timing synchronization circuits adjust the frequency of the carrier signal used in the receiving system 12 to match the frequency of the carrier signal used in the transmitting system 10 so that the detected error becomes zero, enabling correct data demodulation from the received signal.

[0050] In S110, the timing synchronization circuit of the error reduction device 18V,18H determines whether the frequency of the carrier signal used in the transmitting system 10 matches the frequency of the carrier signal used in the receiving system 12. If the frequency of the carrier signal used in the transmitting system 10 matches the frequency of the carrier signal used in the receiving system 12 (Y in operation S110), the timing synchronization circuit of the error reduction device 18V,18H proceeds to operation S120; if synchronization is not established (N in operation S110), it returns to operation S108.

[0051] In S120, the filter coefficient generation circuit 182V,182H (Figure 1C) of the error removal device 18V,18H generates the filter coefficients for the digital filter 184V,184H as described with reference to Equation 1 above, and sets them in the digital filter 184V,184H. In S122, the digital filter 184V,184H filters the combined signals H,V using the set filter coefficients to generate an error-removed signal, which is output to the subtraction circuit 180V,180H.

[0052] In S122, the subtraction circuits 180V and 180H of the error removal devices 18V and 18H subtract the error removal signal from the combined signals V and H, thereby removing the error component from the combined signals V and H, and outputting it to the demodulation and error detection devices 160V and 160H.

[0053] In S124, the demodulation and error detection devices 160V and 160H demodulate the received data V and H corresponding to the transmitted data V and H input to the transmitting system 10 from the combined signal V and H from which the error components have been removed, and output it to a data processing device or the like connected to the receiving system 12.

[0054] In S126, the demodulation and error detection devices 160V and 160H detect the difference between the signal point in the IF signal of the received data V and H demodulated in the operation of S124 and the reference signal point in the IF signal. The demodulation and error detection devices 160V and 160H output the detected difference as error signals V and H to the filter coefficient generation circuits 182V and 182H of the error removal devices 18V and 18H.

[0055] In S128, the filter coefficient generation circuits 182V and 182H detect components included in the error signals V and H that correlate with the composite signals V and H, as explained with reference to Figures 1E and 1F. As mentioned above, the correlation of the composite signals V and H helps to eliminate errors caused by unknown random noise, etc., from the composite signals V and H, as explained with reference to Equation 1 above, and to keep the rate of data errors occurring in the data demodulated from them low.

[0056] In S130, the demodulation and error detection devices 160V and 160H determine whether data communication between the transmitting system 10 and the receiving system 12 (Figure 1) has ended for any reason. The data transmission and reception system 1 terminates processing when data communication has ended (Y in the operation of S130), and returns to the operation of S120 when it has not ended (N in the operation of S130).

[0057] The following describes the normal and abnormal operation of the data transmission and reception system 1 shown in Figures 1A to 1G, Figure 2, etc., with reference to Figures 3A to 4B. In Figures 3A to 4B, components not used in this explanation have been omitted as appropriate. Figure 3A is a diagram illustrating an example of normal operation of the data transmission and reception system 1. Figure 3B is a diagram illustrating an example of normal operation when diversity using frequencies f1, f2 and vertical and horizontal polarization is not performed in the data transmission and reception system 1.

[0058] As shown by the dotted lines in Figure 3A, when the data transmission / reception system 1 is operating normally, all of the transmission radio signals Vf1, Vf2, Hf1, and Hf2 are transmitted from the transmitting system 10 to the receiving system 12. In this case, the receiving devices 146Vf1, 146Vf2, 146Hf1, and 146Hf2 of the receiving system 12 receive the transmission radio signals Vf1, Vf2, Hf1, and Hf2 from the transmitting system 10 and can generate all of the received signals Vf1, Vf2, Hf1, and Hf2 normally.

[0059] The error removal devices 18V and 18H, and the demodulation and error detection devices 160V and 160H perform diversity using frequencies f1 and f2 and vertical and horizontal polarization, thereby removing error signals H and V from the combined signals H and V. When error signals H and V are removed from the combined signals H and V in this way, the error rate of the received data V and H obtained by decoding with the demodulation and error detection devices 160V and 160H is kept low compared to when diversity is not performed.

[0060] On the other hand, as shown by the dotted line in Figure 3B, even if the receiving system 12 does not include receiving devices 146Vf2 and 146Hf2, and only includes receiving devices 146Vf1 and 146Hf1, the diversity described above cannot be performed in the receiving system 12 with reference to Figure 3A. In the case shown in Figure 3B, error signals H and V cannot be removed from the combined signals H and V. Therefore, when diversity is not performed as shown in Figure 3B, the error rate of the received data V and H will be the same as or higher than when diversity is performed as shown in Figure 3A.

[0061] Figure 4A illustrates an example of abnormal operation of the data transmission / reception system 1. Figure 4B illustrates an example of abnormal operation when diversity is not performed in the data transmission / reception system 1. When an abnormality such as a wireless line failure occurs in the data transmission / reception system 1, for example, as shown by the dotted line in Figure 4A, only the transmission radio signals Vf1, Vf2, and Hf1 may be transmitted from the transmitting system 10 to the receiving system 12, and the transmission radio signal Hf2 may not be transmitted. In such a case, the receiving devices 146Vf1 and 146Hf1 in the receiving system 12 can generate both the received signals Vf1 and Hf1. Therefore, the receiving system 12 reproduces the received data V with a low error rate, as in the normal operation of the data transmission / reception system 1 shown in Figure 3A.

[0062] On the other hand, as shown in Figure 4B, if diversity is not performed in the data transmission / reception system 1 and only the receiving device 146Hf2 is operating normally, the receiving device 146Hf2 cannot receive the transmission signal Hf1, which has a different frequency f1 than frequency f2. Also, since the transmission signal Hf2 is not transmitted from the transmitting system 10, the receiving device 146Hf2 cannot receive the received signal Hf2. In other words, since the receiving device 146Hf2 cannot receive either the transmission signals Hf1 or Hf2 modulated by the transmission data V, the receiving system 12 does not demodulate the received data V at all.

[0063] As explained above, the data transmission and reception system 1 allows for a higher data rate (approximately double) that can be transmitted from the transmitting system 10 to the receiving system 12 during normal operation, and also reduces the error rate of the demodulated received data V and H. Furthermore, with the data transmission and reception system 1, even if an anomaly occurs where some of the transmitted radio signals Vf1, Vf2, Hf1, and Hf2 are not transmitted from the transmitting system 10 to the receiving system 12, there is a higher probability that at least one of the received data V and H will be demodulated.

[0064] Furthermore, using the data transmission / reception system 1 in microwave frequency bands such as the 6GHz, 6.5GHz, 7.5GHz, and 11GHz bands can help mitigate interference with radio wave signal transmission, such as fading due to radio wave interference and signal level degradation due to rainfall. Additionally, by performing frequency diversity, the data transmission / reception system 1 transmits radio signals of different frequencies in both vertical and horizontal polarizations. This allows for transmission of radio signals in other polarizations or frequencies that are normally transmittable, even if transmission becomes impossible in one polarization or frequency. Moreover, when operating normally, the data transmission / reception system 1 can improve the quality of data transmission via radio signals compared to systems without diversity. Finally, the data transmission / reception system 1 can minimize the influence of one polarization's radio signal on other polarizations.

[0065] Some or all of the above embodiments may also be described as follows, but are not limited to the following: [Note 1] (See Perspective 1 of the above disclosure) [Note 2] A second error detection device that generates a second error signal indicating the error between a second reference signal point indicating a reference for the signal point of the symbol of the second data in the second received signal and the second signal point of the symbol of the second data demodulated from the second received signal, A second error removal device that removes errors from the second received signal based on the second error signal and the first received signal. A data communication device as described in Appendix 1, further comprising the features described above. [Note 3] The first direction and the third direction are the same, The second direction and the fourth direction are the same. A data communication device as described in Appendix 1 or 2. [Note 4] The first and third directions are orthogonal to the second and fourth directions. A data communication device as described in any of the appendices 1 to 3. [Note 5] A first combining device that combines the first received signal and the second received signal received by the first receiving device to generate a first combined signal. Furthermore, The first error detection device generates a first error signal that indicates the error between the first reference signal point and the first signal point in the first composite signal. A data communication device as described in any of the appendices 1 to 4. [Note 6] A second combining device generates a second combined signal by combining the first received signal and the second received signal received by the second receiving device. Furthermore, The second error detection device generates a second error signal that indicates the error between the second reference signal point and the second signal point in the second composite signal. A data communication device as described in any of the appendices 1 to 5. [Note 7] (See the second perspective in the above disclosure.) [Note 8] To generate a second error signal that indicates the error between a second reference signal point indicating the reference of the signal point of the symbol of the second data in the second received signal and the second signal point of the symbol of the second data demodulated from the second composite signal, Based on the second error signal and the first composite signal, the error is removed from the second composite signal. A data communication method as described in Appendix 7, comprising the following: [Note 9] (See the third perspective in the above disclosure.) [Note 10] A process for generating a second error signal that indicates the error between a second reference signal point indicating the reference of the signal point of the symbol of the second data in the second received signal and the second signal point of the symbol of the second data demodulated from the second composite signal, A process to remove the error from the second combined signal based on the second error signal and the first combined signal. A data communication program described in Appendix 9, which is further executed by the aforementioned processor. It goes without saying that any combination of the forms described in the appendices of this disclosure, or any combination of the elements described in each perspective and embodiment (including the non-selection of some elements), can be made from time to time by those skilled in the art, in accordance with the basic concepts of this disclosure.

[0066] Furthermore, each disclosure of the above-mentioned patent documents and other materials cited is incorporated into this publication by reference. Within the framework of this disclosure (including the claims), further modifications and adjustments to the embodiments or examples are possible based on their fundamental technical concept. Also, within the framework of this disclosure, various combinations or selections (including partial deletions) of various disclosed elements (including each element of each claim, each element of each embodiment or example, each element of each drawing, etc.) are possible. In other words, this disclosure naturally includes various modifications and changes that a person skilled in the art could make in accordance with the entire disclosure, including the claims, and the technical concept. In particular, the numerical ranges described in this publication should be interpreted as specifically describing any numerical value or sub-range included within that range, even if not specifically noted. Furthermore, each disclosure of the above-mentioned cited documents is deemed to be included in the disclosures of this application, which may be used in part or in whole as part of this disclosure, in accordance with the spirit of this disclosure, as necessary. [Explanation of Symbols]

[0067] 1. Data transmission and reception system 10. Transmitter System 12. Receiving system (data communication device) 14-1, 14-2 Data Communication System 14V, 14H Antenna 140V Vertical Polarization Transceiver System 140H Horizontal Polarization Transceiver System 142V, 142H signal combiner (first combiner, second combiner) 144Vf1, 144Vf2, 144Hf1, 144Hf2 Transmitter 146Vf1, 146Vf2, 146Hf1, 146Hf2 receiving equipment (first receiving equipment, second receiving equipment) 16 Modulation and Demodulation System 160V, 160H Demodulation and Error Detection Device (First Error Detection Device, Second Error Detection Device) 162V, 162H Modulator 18V, 18H Error Removal Device (First Error Removal Device, Second Error Removal Device) 180V, 180H Subtraction Circuit 182V, 182H filter coefficient generation circuit 184V, 184H Digital Filter

Claims

1. A first receiving device that receives a first radio signal of a first frequency, which includes a symbol of first data and is transmitted with polarization in a first direction, and a second radio signal of a second frequency, which includes a symbol of second data and is transmitted with polarization in a second direction different from the first direction, with polarization in a third direction to generate a first received signal, A second receiving device that receives the first radio signal and the second radio signal with polarization in a fourth direction different from the third direction to generate a second received signal, A first error detection device that generates a first error signal indicating the error between a first reference signal point indicating a reference for the signal point of the symbol of the first data in the first received signal and the first signal point of the symbol of the first data demodulated from the first received signal, A first error removal device that removes an error from the first received signal based on the first error signal and the second received signal, A data communication device equipped with the following features.

2. A second error detection device that generates a second error signal indicating the error between a second reference signal point indicating the reference of the signal point of the symbol of the second data in the second received signal and the second signal point of the symbol of the second data demodulated from the second received signal, A second error removal device that removes errors from the second received signal based on the second error signal and the first received signal, The data communication device according to claim 1, further comprising:

3. The first direction and the third direction are the same, The second direction and the fourth direction are the same. The data communication device according to claim 2.

4. The first and third directions are orthogonal to the second and fourth directions. The data communication device according to claim 3.

5. A first combining device that combines the first received signal and the second received signal received by the first receiving device to generate a first combined signal. Furthermore, The first error detection device generates a first error signal that indicates the error between the first reference signal point and the first signal point in the first composite signal. The data communication device according to claim 4.

6. A second combining device generates a second combined signal by combining the first received signal and the second received signal received by the second receiving device. Furthermore, The second error detection device generates a second error signal that indicates the error between the second reference signal point and the second signal point in the second composite signal. The data communication device according to claim 5.

7. A first radio signal of a first frequency, which includes a symbol of the first data and is transmitted with polarization in a first direction, and a second radio signal of a second frequency, which includes a symbol of the second data and is transmitted with polarization in a second direction different from the first direction, are received with polarization in a third direction to generate a first received signal. The first radio signal and the second radio signal are received with polarization in a fourth direction different from the third direction to generate a second received signal, The first received signal and the second received signal are combined to generate a first combined signal, The received first received signal and the second received signal are combined to generate a second combined signal, To generate a first error signal that indicates the error between a first reference signal point indicating the reference of the signal point of the symbol of the first data in the first received signal and the first signal point of the symbol of the first data demodulated from the first composite signal, Based on the first error signal and the second combined signal, the error is removed from the first combined signal. A data communication method that includes this.

8. To generate a second error signal that indicates the error between a second reference signal point indicating the reference of the signal point of the symbol of the second data in the second received signal and the second signal point of the symbol of the second data demodulated from the second composite signal, Based on the second error signal and the first composite signal, the error is removed from the second composite signal. The data communication method according to claim 7, comprising:

9. A process of generating a first received signal by receiving a first radio signal of a first frequency, which includes a symbol of first data and is transmitted with polarization in a first direction, and a second radio signal of a second frequency, which includes a symbol of second data and is transmitted with polarization in a second direction different from the first direction, with polarization in a third direction, A process of receiving the first radio signal and the second radio signal with polarization in a fourth direction different from the third direction to generate a second received signal, A process of generating a first combined signal by combining the received first received signal and the second received signal, A process of generating a second combined signal by combining the received first received signal and the second received signal, A process for generating a first error signal that indicates the error between a first reference signal point indicating the reference of the signal point of the symbol of the first data in the first received signal and the first signal point of the symbol of the first data demodulated from the first composite signal, A process to remove errors from the first combined signal based on the first error signal and the second combined signal. A data communication program that causes the processor to execute.

10. A process for generating a second error signal that indicates the error between a second reference signal point indicating the reference of the signal point of the symbol of the second data in the second received signal and the second signal point of the symbol of the second data demodulated from the second composite signal, A process to remove errors from the second combined signal based on the second error signal and the first combined signal. The data communication program according to claim 9, which further causes the processor to execute the following.

Images