Signal processing device, signal processing method, recording medium, and mobile object

Abstract

A signal processing device, a signal processing method, a recording medium, and a mobile object are provided. The signal processing device includes a first transmission path estimation unit, a second transmission path estimation unit, a weight calculation unit, a weighting unit, a synchronization processing unit, and a handover control unit. When a handover candidate signal is indicated, the synchronization processing unit determines whether a received signal obtained by an antenna corresponding to a polarization different from the transmission signal, either a vertically polarized wave antenna or a horizontally polarized wave antenna, or a handover candidate signal satisfies a predetermined condition. When the synchronization processing unit determines that the received signal or the handover candidate signal satisfies the predetermined condition, the handover control unit outputs a handover execution signal. When the synchronization processing unit, the first transmission path estimation unit, the second transmission path estimation unit, the weight calculation unit, and the weighting unit receive the handover execution signal and switch the signal being processed from the transmission signal to the handover candidate signal.

Description

[0001] This application was filed on January 29, 2019, with Chinese patent application number 201980010444.4 (international application number PCT / JP2019 / 002856), and is a divisional application of the patent application entitled “Signal processing device, signal processing method, program and mobile body”. Technical Field

[0002] The present disclosure relates to processing performed to receive a signal transmitted from a transmitting device such as a satellite, for example. Background Art

[0003] For passengers in an aircraft in flight, Internet connection or live TV distribution services are actively provided, and these services are provided via satellite (Non-Patent Document 1). In recent years, HTS (High Throughput Satellite) has been gradually introduced, and the throughput under the same bandwidth has been improved compared with previous models by using technologies such as multi-spot beams and frequency reuse (Non-Patent Document 2). As an example of a multi-spot beam, a 4-spot beam repetition (4 colors) can be cited (Chapter 4.4.2 of Non-Patent Document 3). In the repetition of the 4-spot beam, two orthogonal polarization waves (for example, V (Vertical) polarization wave and H (Horizontal) polarization wave) are applied to each of the two bands.

[0004] Prior art literature

[0005] Non-patent literature

[0006] Non-Patent Document 1: “Needs for Satellite Communications in the Aeronautical Field and Expectations for Next-Generation Communication Satellites,” Seminar on Future Outlook for Next-Generation Technology Experimental Satellites 2016 (Mar. 2016) (http: / / www.mri.co.jp / news / seminar / uploadfiles / ssu20160330.pdf)

[0007] Non-Patent Document 2: “Global Trends in Satellite Communication Services,” Seminar on Future Outlook of Next-Generation Technology Experimental Satellites 2016 (Mar. 2016) (http: / / www.mri.co.jp / news / seminar / uploadfiles / ssu20160330.pdf)

[0008] Non-Patent Document 3: DVB blue book A171-2 (March 2015): Digital Video Broadcasting (DVB); Implementation guidelines for the second generation system for Broadcasting, Interactive Services, News Gathering and other broadband satellite applications; Part 2-S2 Extensions (DVB-S2X) (https: / / www.dvb.org / resources / public / standards / A171-2%20S2X%20imp.pdf)

[0009] Non-Patent Document 4: Draft ETSI EN 302 307-2v1.1.1 (October 2014): Digital Video Broadcasting (DVB); Second generation framing structure, channel coding and modulation systems for Broadcasting, Interactive Services, News Gathering and other broadband satellite applications; DVB-S2 Extensions (DVB-S2X) (http: / / www.etsi.org / deliver / etsi_en / 302300_302399 / 30230702 / 01.01.01_20 / en_30230702v010101a.pdf)

[0010] Non-patent document 5: DVB blue book A171-1 (March 2015): Digital Video Broadcasting (DVB); Implementation guidelines for the second generation system for Broadcasting, Interactive Services, News Gathering and other broadband satellite applications; Part 1(DVB-S2)(https: / / www.dvb.org / resources / public / standards / a171-1_s2_guide.pdf)

[0011] Non-Patent Document 6: ETSI EN 301 545-2 v1.2.1 (April 2014): Digital Video Broadcasting (DVB); Second Generation DVB Interactive Satellite System (DVB-RCS2); Part 2: Lower Layers for Satellite standard (http: / / www.etsi.org / deliver / etsi_en / 301500_301599 / 30154502 / 01.02.01_60 / en_30154502v010201p.pdf) Summary of the Invention

[0012] Problems to be solved by the invention

[0013] However, conventional signal processing devices for receiving signals transmitted from transmitting devices such as satellites have a problem of insufficient performance.

[0014] Therefore, in the present disclosure, a signal processing device capable of improving performance is provided.

[0015] Means for solving problems

[0016] A signal processing device according to one embodiment of the present disclosure includes: a first transmission path estimation unit for estimating a first transmission path characteristic of the transmission signal using a vertical signal and a horizontal signal obtained by receiving a transmission signal transmitted from a transmission device in one of a vertically polarized wave and a horizontally polarized wave using an antenna for vertically polarized waves and an antenna for horizontally polarized waves; a second transmission path estimation unit for estimating a second transmission path characteristic of the transmission signal using the horizontal signal; a weight calculation unit for calculating a first weight corresponding to the vertical signal and a second weight corresponding to the horizontal signal using the first and second transmission path characteristics; a weighting unit for performing weighted addition on the vertical signal and the horizontal signal using the first and second weights; a synchronization processing unit for performing synchronization processing on each of the vertical signal and the horizontal signal; and a handover control unit for instructing handover candidate signals, wherein the first transmission path characteristic is a characteristic of a transmission path for transmitting the transmission signal from the transmission device to the antenna for vertically polarized waves, and the second transmission path characteristic is a characteristic of a transmission path for transmitting the transmission signal from the transmission device to the antenna for vertically polarized waves, and the second transmission path characteristic is a characteristic of a transmission path for transmitting the transmission signal from the transmission device to the antenna for vertically polarized waves. a characteristic of a transmission path for transmitting the transmission signal from the transmission device to the horizontally polarized wave antenna, wherein the first transmission path characteristic indicates a ratio of a signal contained in the vertical signal within the transmission signal, and the second transmission path characteristic indicates a ratio of a signal contained in the horizontal signal within the transmission signal. When the handover candidate signal is indicated, the synchronization processing unit determines whether a received signal obtained by an antenna corresponding to a polarization different from that of the vertically polarized wave antenna and the horizontally polarized wave antenna, or the handover candidate signal, satisfies a predetermined condition. When the synchronization processing unit determines that the received signal or the handover candidate signal satisfies the predetermined condition, the handover control unit outputs a handover execution signal. Upon receiving the handover execution signal, the synchronization processing unit, the first transmission path estimation unit, the second transmission path estimation unit, the weight calculation unit, and the weighting unit switch a signal to be processed from the transmission signal to the handover candidate signal.

[0017] A signal processing method according to one embodiment of the present disclosure includes: estimating a first transmission path characteristic of the transmission signal using the vertical signal and estimating a second transmission path characteristic of the transmission signal using the horizontal signal, among a vertical signal and a horizontal signal obtained by receiving a transmission signal transmitted from a transmission device in one of a vertically polarized wave and a horizontally polarized wave using an antenna for a vertically polarized wave and an antenna for a horizontally polarized wave; calculating a first weight corresponding to the vertical signal and a second weight corresponding to the horizontal signal using the first transmission path characteristic and the second transmission path characteristic; performing weighted addition on the vertical signal and the horizontal signal using the first weight and the second weight; performing synchronization processing on each of the vertical signal and the horizontal signal, indicating a handover candidate signal; and determining, in accordance with the indication of the handover candidate signal, a reception signal received by an antenna corresponding to a polarization wave different from the transmission signal, of the vertically polarized wave antenna and the horizontally polarized wave antenna. The method further comprises: determining whether the received signal or the handover candidate signal satisfies a predetermined condition, outputting a handover execution signal when it is determined that the received signal or the handover candidate signal satisfies the predetermined condition, and switching the signal to be processed from the transmitted signal to the handover candidate signal in accordance with the output of the handover execution signal during the synchronization processing, estimating the first transmission path characteristic, estimating the second transmission path characteristic, calculating the first weight, calculating the second weight, and performing the weighted addition. The first transmission path characteristic is a characteristic of a transmission path for transmitting the transmitted signal from the transmitting device to the antenna for vertically polarized waves, and the second transmission path characteristic is a characteristic of a transmission path for transmitting the transmitted signal from the transmitting device to the antenna for horizontally polarized waves. The first transmission path characteristic indicates a ratio of a signal contained in the vertical signal within the transmitted signal, and the second transmission path characteristic indicates a ratio of a signal contained in the horizontal signal within the transmitted signal.

[0018] One embodiment of the present disclosure relates to a computer-readable nonvolatile recording medium having a program recorded thereon, the program causing a computer to execute the following steps: estimating a first transmission path characteristic of the transmission signal using the vertical signal and estimating a second transmission path characteristic of the transmission signal using the horizontal signal, among vertical and horizontal signals obtained by receiving a transmission signal transmitted from a transmission device using one of a vertically polarized wave and a horizontally polarized wave via an antenna for vertically polarized waves and an antenna for horizontally polarized waves; calculating a first weight corresponding to the vertical signal and a second weight corresponding to the horizontal signal using the first and second transmission path characteristics; performing weighted addition on the vertical signal and the horizontal signal using the first and second weights; performing synchronization processing on each of the vertical signal and the horizontal signal, instructing a handover candidate signal; and determining, in accordance with the instruction of the handover candidate signal, whether to transmit a signal corresponding to a polarization wave different from the transmission signal via the antenna for vertically polarized waves and the antenna for horizontally polarized waves. The method further comprises determining whether a received signal obtained by receiving the vertically polarized wave antenna or the handover candidate signal satisfies a predetermined condition, outputting a handover execution signal if it is determined that the received signal or the handover candidate signal satisfies the predetermined condition, and switching the signal to be processed from the transmission signal to the handover candidate signal in accordance with the output of the handover execution signal during the synchronization processing, estimating the first transmission path characteristic, estimating the second transmission path characteristic, calculating the first weight, calculating the second weight, and performing the weighted addition. The first transmission path characteristic is a characteristic of a transmission path for transmitting the transmission signal from the transmission device to the antenna for vertically polarized waves, and the second transmission path characteristic is a characteristic of a transmission path for transmitting the transmission signal from the transmission device to the antenna for horizontally polarized waves. The first transmission path characteristic indicates a ratio of a signal contained in the vertical signal in the transmission signal, and the second transmission path characteristic indicates a ratio of a signal contained in the horizontal signal in the transmission signal.

[0019] A mobile object according to one embodiment of the present disclosure includes: a signal processing device; an antenna for vertically polarized waves; and an antenna for horizontally polarized waves, wherein the signal processing device includes: a first transmission path estimation unit for estimating a first transmission path characteristic of the transmission signal using the vertical signal, among a vertical signal and a horizontal signal obtained by receiving a transmission signal transmitted from a transmission device in one of vertically polarized waves and horizontally polarized waves by the vertically polarized wave antenna and the horizontally polarized wave antenna; a second transmission path estimation unit for estimating a second transmission path characteristic of the transmission signal using the horizontal signal; a weight calculation unit for calculating a first weight corresponding to the vertical signal and a second weight corresponding to the horizontal signal using the first transmission path characteristic and the second transmission path characteristic; a weighting unit for performing weighted addition on the vertical signal and the horizontal signal using the first weight and the second weight; a synchronization processing unit for performing synchronization processing on each of the vertical signal and the horizontal signal; and a handover control unit for instructing handover candidate signals, wherein the first transmission path characteristic is a characteristic for the transmission signal transmitted from the transmission device to the vertically polarized wave antenna. The second transmission path characteristic is a characteristic of a transmission path for transmitting the transmission signal from the transmission device to the horizontally polarized wave antenna. The first transmission path characteristic indicates a ratio of a signal contained in the vertical signal in the transmission signal, and the second transmission path characteristic indicates a ratio of a signal contained in the horizontal signal in the transmission signal. When the handover candidate signal is indicated, the synchronization processing unit determines whether a received signal obtained by an antenna corresponding to a polarization different from the transmission signal, either the vertically polarized wave antenna or the horizontally polarized wave antenna, or the handover candidate signal satisfies a predetermined condition. When the synchronization processing unit determines that the received signal or the handover candidate signal satisfies the predetermined condition, the handover control unit outputs a handover execution signal. When the handover execution signal is received, the synchronization processing unit, the first transmission path estimation unit, the second transmission path estimation unit, the weight calculation unit, and the weighting unit switch a signal to be processed from the transmission signal to the handover candidate signal.

[0020] A signal processing device according to one embodiment of the present disclosure includes: a first transmission path estimation unit for estimating a first transmission path characteristic of the transmission signal using a vertical signal and a horizontal signal obtained by receiving a transmission signal transmitted from a transmission device in one of vertically polarized waves and horizontally polarized waves using an antenna for vertically polarized waves and an antenna for horizontally polarized waves; a second transmission path estimation unit for estimating a second transmission path characteristic of the transmission signal using the horizontal signal; a weight calculation unit for calculating a first weight corresponding to the vertical signal and a second weight corresponding to the horizontal signal using the first and second transmission path characteristics; and a weighting unit for performing weighted addition on the vertical signal and the horizontal signal using the first and second weights, wherein the first transmission path characteristic is a characteristic of the transmission path for transmitting the transmission signal from the transmission device to the antenna for vertically polarized waves, and the second transmission path characteristic is a characteristic of the transmission path for transmitting the transmission signal from the transmission device to the antenna for horizontally polarized waves.

[0021] Furthermore, these general or specific aspects may also be implemented through systems, methods, integrated circuits, computer programs, or computer-readable recording media such as CD-ROMs, or through any combination of systems, methods, integrated circuits, computer programs, and recording media. Furthermore, the recording medium may be a non-volatile recording medium.

[0022] Effects of the Invention

[0023] The signal processing device disclosed herein can improve performance.

[0024] Further advantages and effects of one embodiment of the present disclosure are made clear by the description and drawings. The relevant advantages and / or effects are provided by several embodiments and the features described in the description and drawings, but it is not necessary to provide all of them in order to obtain one or more of the same features. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a diagram showing an example of the configuration of the communication system in Embodiment 1.

[0026] Figure 2 This is a diagram showing a frame structure of the DVB-S2X standard transmitted from a satellite antenna in the first embodiment.

[0027] Figure 3 This is a diagram showing an example of the configuration of a communication device mounted on an aircraft in the first embodiment.

[0028] Figure 4 This is a diagram showing an example of the frequency spectrum of the input IF signal in the first embodiment.

[0029] Figure 5 This is a diagram showing an example of the configuration of a tuner unit in the first embodiment.

[0030] Figure 6 This is a diagram showing an example of the configuration of a synchronization processing unit in the first embodiment.

[0031] Figure 7 This is a diagram showing an example of the configuration of a polarization signal processing unit in the first embodiment.

[0032] Figure 8 This is a diagram showing an example of the configuration of a transmission path estimation unit in the first embodiment.

[0033] Figure 9 This is a flowchart showing an example of the processing operation of the signal processing device in the first embodiment.

[0034] Figure 10 This is a flowchart showing another example of the processing operation of the signal processing device in the first embodiment.

[0035] Figure 11 This is a diagram showing an example of the configuration of a communication device in Embodiment 2.

[0036] Figure 12 This is a diagram showing an example of the configuration of a polarization signal processing unit in the second embodiment.

[0037] Figure 13 This is a diagram showing the configuration of a transmission path estimation unit in the second embodiment.

[0038] Figure 14 This is a diagram showing an example of the configuration of a transmission path estimation unit in a modified example of the second embodiment.

[0039] Figure 15 This is a diagram showing an example of the configuration of a communication device in Embodiment 3.

[0040] Figure 16 This is a diagram showing an example of the configuration of an IF transmission signal generating unit in the third embodiment.

[0041] Figure 17 This is a diagram showing an example of the configuration of a communication device in a modified example of the third embodiment.

[0042] Figure 18 This is a diagram showing an example of the configuration of a communication device in a fourth embodiment.

[0043] Figure 19 This is a diagram showing an example of the configuration of a synchronization processing unit in the fourth embodiment.

[0044] Figure 20This is a diagram showing an example of the configuration of a polarization shifting unit in the fourth embodiment.

[0045] Figure 21 This is a flowchart showing an example of the processing operation of the signal processing device in embodiment 4.

[0046] Figure 22 This is a diagram showing an example of the configuration of a communication device in Embodiment 5.

[0047] Figure 23 This is a diagram showing an example of the configuration of a synchronization processing unit in the fifth embodiment.

[0048] Figure 24 This is a diagram showing an example of the configuration of a polarization signal processing unit in the fifth embodiment.

[0049] Figure 25 This is a diagram showing an example of the configuration of a communication device in Embodiment 6.

[0050] Figure 26 This is a diagram showing an example of the configuration of a synchronization processing unit in the sixth embodiment.

[0051] Figure 27 This is a flowchart showing an example of the processing operation of the signal processing device in embodiment 6.

[0052] Figure 28 This figure shows the positions of pilot blocks included in the frame structure of the DVB-S2X standard.

[0053] Figure 29 This is a diagram showing an example of the configuration of a communication device in Embodiment 7.

[0054] Figure 30 This is a diagram showing an example of the configuration of a synchronization processing unit in the seventh embodiment.

[0055] Figure 31 This is a diagram showing an example of the configuration of a polarization signal processing unit in the seventh embodiment.

[0056] Figure 32 This diagram shows the super frame (SF) structure of the DVB-S2X standard.

[0057] Figure 33 This is a diagram showing an example of the configuration of a communication device in Embodiment 8.

[0058] Figure 34 This is a diagram showing an example of the configuration of a synchronization processing unit in the eighth embodiment.

[0059] Figure 35 This is a diagram showing an example of the configuration of a polarization signal processing unit in the eighth embodiment.

[0060] Figure 36 This is a diagram showing an example of the configuration of a communication device in Implementation Example 9.

[0061] Figure 37 This is a diagram showing an example of the configuration of a synchronization processing unit in the ninth embodiment.

[0062] Figure 38 This is a diagram showing an example of the configuration of a communication device in embodiment 10.

[0063] Figure 39 This is a diagram showing an example of the configuration of a communication device in Modification 1 of Implementation Example 10.

[0064] Figure 40 This is a diagram showing an example of the configuration of a communication device in Modification 2 of Implementation Example 10.

[0065] Figure 41 This is a diagram showing an example of the configuration of a polarization signal processing unit in Modification 2 of Implementation 10.

[0066] Figure 42 This is a flowchart showing an example of the processing operation of the signal processing device in embodiment 10.

[0067] Figure 43 This is a diagram showing an example of the configuration of a communication device in embodiment 11.

[0068] Figure 44 This is a diagram showing an example of the configuration of a synchronization processing unit in the eleventh embodiment.

[0069] Figure 45 This is a diagram showing an example of the configuration of a polarization signal processing unit in the eleventh embodiment.

[0070] Figure 46 This is a flowchart showing an example of the processing actions of the signal processing device in embodiment 11.

[0071] Figure 47 This is a diagram showing an example of the configuration of a communication device in embodiment 12.

[0072] Figure 48 This is a diagram showing an example of the configuration of a synchronization processing unit in the twelfth embodiment.

[0073] Figure 49 This is a flowchart showing an example of the processing actions of the signal processing device in embodiment 12.

[0074] Figure 50 This is a diagram showing an example of the configuration of a communication device in embodiment 13.

[0075] Figure 51 This is a diagram showing an example of the minimum bandwidth that the tuner unit and the A / D converter unit in the thirteenth embodiment allow to pass.

[0076] Figure 52 This is a diagram showing an example of the configuration of a synchronization processing unit in embodiment 13.

[0077] Figure 53 This is a flowchart showing an example of the processing actions of the signal processing device in embodiment 13.

[0078] Figure 54 This is a diagram showing an example of the configuration of a communication device in a fourteenth embodiment.

[0079] Figure 55 This is a diagram showing an example of the minimum bandwidth that the tuner unit and the A / D converter unit in the fourteenth embodiment allow to pass.

[0080] Figure 56 This is a diagram showing an example of the configuration of a synchronization processing unit in the fourteenth embodiment.

[0081] Figure 57 This is a flowchart showing an example of the processing actions of the signal processing device in embodiment 14.

[0082] Figure 58 This is a diagram showing an example of the configuration of a communication device in embodiment 15.

[0083] Figure 59 This is a diagram showing an example of the configuration of a polarization signal processing unit in embodiment 15.

[0084] Figure 60 This is a flowchart showing an example of the processing actions of the signal processing device in embodiment 15. DETAILED DESCRIPTION

[0085] (Knowledge serving as the basis of this disclosure)

[0086] The present inventors have discovered that the following problems arise with respect to the conventional signal processing described in the “Background Art” section.

[0087] When receiving satellite signals on a mobile object such as an aircraft, polarization changes moment by moment based on the positional relationship between the satellite and the mobile object, as well as fluctuations in the roll and yaw of the mobile object and the satellite, degrading reception performance. This becomes more pronounced in aircraft traveling at high speeds and over long distances. To address this, aircraft calculate the polarization angle based on the positional relationship between the satellite and the aircraft (latitude and longitude information), and mechanically or electronically change the plane of polarization to minimize degradation in reception performance.

[0088] However, it is impossible to achieve a precise optimal point. Furthermore, there are problems such as the inability to track the attitude of the object or satellite, and the need to pre-adjust the phase and power of the RF (Radio Frequency) front-end circuits, including the V- and H-polarized antennas.

[0089] In contrast, when using right-handed or left-handed polarized waves, there is no need to consider changing the polarization plane. However, in circularly polarized transponders for right-handed or left-handed polarized waves, for example, the number of transmission amplifiers must be doubled, resulting in increased costs and making it difficult to use circularly polarized transponders for all satellite beams.

[0090] To address such issues, a signal processing device according to one embodiment of the present disclosure includes: a first transmission path estimation unit for estimating a first transmission path characteristic of the transmission signal using the vertical signal, from among a vertical signal and a horizontal signal obtained by receiving a transmission signal transmitted from a transmission device in the form of either a vertically polarized wave or a horizontally polarized wave using an antenna for vertically polarized waves and an antenna for horizontally polarized waves; a second transmission path estimation unit for estimating a second transmission path characteristic of the transmission signal using the horizontal signal; a weight calculation unit for calculating a first weight corresponding to the vertical signal and a second weight corresponding to the horizontal signal using the first and second transmission path characteristics; and a weighting unit for performing weighted addition on the vertical signal and the horizontal signal using the first and second weights. For example, the first transmission path characteristic may indicate a ratio of a signal included in the vertical signal in the transmission signal, and the second transmission path characteristic may indicate a ratio of a signal included in the horizontal signal in the transmission signal.

[0091] Thus, to receive a signal transmitted from a transmitting device such as a satellite, not only the signal obtained from the antenna corresponding to the signal's polarization is used, but also the signal obtained from the antenna corresponding to a polarization orthogonal to the signal's polarization. In other words, both vertical and horizontal signals are used. Furthermore, these vertical and horizontal signals are weighted and added using weights corresponding to their respective transmission path characteristics. This improves signal processing performance. Specifically, if the weights are, for example, MMSE weights, even if the polarization of the transmitted signal changes constantly, the received SNR, which degrades due to deviations of the polarization plane from the optimal point, can be improved. Furthermore, the received SINR can also be improved.

[0092] In addition, the signal processing device may also include: a synchronization processing unit that performs synchronization processing on the vertical signal and the horizontal signal respectively, the first transmission path estimation unit and the second transmission path estimation unit use the vertical signal and the horizontal signal that have completed the synchronization processing to estimate the first transmission path characteristic and the second transmission path characteristic, the weighting unit performs the weighted addition on the vertical signal and the horizontal signal that have completed the synchronization processing, and the synchronization processing unit includes: a first synchronization processing unit that performs synchronization processing on the vertical signal; and a second synchronization processing unit that performs synchronization processing on the horizontal signal, and the first synchronization processing unit and the second synchronization processing unit cooperate with each other to make the frequency difference and phase difference between the vertical signal and the horizontal signal close to 0, respectively.

[0093] For example, when two polarized wave signals received by an antenna are multiplexed and transmitted to a communication device via a single cable, the resulting frequency and phase deviations can degrade reception performance. However, in one embodiment of the present disclosure, synchronization processing of the vertical and horizontal signals is coordinated to minimize the frequency and phase differences, thereby suppressing synchronization deviations corresponding to the vertical and horizontal signals.

[0094] Alternatively, the first synchronization processing unit and the second synchronization processing unit may cooperate with each other to reduce a clock timing error between the vertical signal and the horizontal signal and to stabilize a power sum of the vertical signal and the horizontal signal.

[0095] This makes it possible to improve the accuracy of synchronization processing corresponding to the vertical signal and the horizontal signal.

[0096] Alternatively, the signal processing device may further include: a polarization shifting unit that assigns an offset to the vertical signal and the horizontal signal; and a synchronization processing unit that performs synchronization processing on the vertical signal and the horizontal signal after being assigned the offset, respectively; the first transmission path estimation unit and the second transmission path estimation unit use the vertical signal and the horizontal signal that have undergone synchronization processing to estimate the first transmission path characteristics and the second transmission path characteristics; the weighting unit performs the weighted addition on the vertical signal and the horizontal signal that have undergone synchronization processing; and the polarization shifting unit assigns an offset to the vertical signal and the horizontal signal that are to be subsequently synchronized based on at least one of a result of the synchronization processing by the synchronization processing unit and information contained in the signal obtained by the weighted addition.

[0097] This allows the vertical and horizontal signals to be offset to obtain the desired signal, even in the presence of an interference signal similar to the satellite signal (i.e., the desired signal) from the transmitter. This allows the desired signal to be distinguished from the interference signal, mitigating the effects of the interference component and improving the received SINR.

[0098] Furthermore, the signal processing device may further include an equalizer configured to perform equalization processing on the vertical signal and the horizontal signal, or on the signal obtained by the weighted addition.

[0099] By performing equalization, the influence of inter-symbol interference (ISI) can be reduced. In other words, the influence of delayed waves can be reduced. As a result, the received SINR can be improved.

[0100] Alternatively, the signal processing device may further include: a synchronization processing unit that performs synchronization processing on the vertical signal and the horizontal signal respectively; and a handover control unit that indicates a handover candidate signal having a frequency different from that of the transmission signal. When the handover candidate signal is indicated, (i) the weighting unit does not perform the weighted addition, and (ii) the synchronization processing unit determines whether the received signal obtained by receiving the antenna corresponding to the polarization wave different from the transmission signal among the antenna for the vertical polarization wave and the antenna for the horizontal polarization wave satisfies a prescribed condition. When it is determined that the received signal satisfies the prescribed condition, the handover control unit outputs a handover execution signal. When the synchronization processing unit, the first transmission path estimation unit, the second transmission path estimation unit, the weight calculation unit, and the weighting unit switch the signal to be processed from the transmission signal to the handover candidate signal when the handover execution signal is obtained.

[0101] As a result, when handover is performed, even though, for example, weighted addition of MMSE is suspended, handover can be performed appropriately.

[0102] Alternatively, the signal processing device may further include: a synchronization processing unit that performs synchronization processing on the vertical signal and the horizontal signal respectively; and a handover control unit that indicates a handover candidate signal having the same frequency and a different polarization wave as the transmission signal. When the synchronization processing unit is indicated with the handover candidate signal, the synchronization processing unit determines whether the handover candidate signal satisfies a prescribed condition based on a correlation value between information contained in the signals respectively received by the antenna for the vertical polarization wave and the antenna for the horizontal polarization wave and known information. When it is determined that the handover candidate signal satisfies the prescribed condition, the handover control unit outputs a handover execution signal. When the synchronization processing unit, the first transmission path estimation unit, the second transmission path estimation unit, the weight calculation unit, and the weighting unit, upon obtaining the handover execution signal, switch the signal to be processed from the transmission signal to the handover candidate signal.

[0103] This allows for continuous detection of synchronization timing corresponding to the desired signal even during handover. Consequently, weighted addition corresponding to the desired signal can be performed continuously even during handover, particularly improving SINR near the cell edge.

[0104] Alternatively, the signal processing device may further include: a tuner unit for passing a signal of a currently set frequency band among signals received by the antenna for the vertically polarized wave and the antenna for the horizontally polarized wave; a synchronization processing unit for performing synchronization processing on the vertical signal and the horizontal signal respectively having passed through the tuner unit; and a handover control unit for indicating a handover candidate signal having at least one of a frequency and a polarization wave different from that of the transmitted signal, and when the handover candidate signal is indicated, (i) the tuner unit expands the frequency band to allow the handover candidate signal to pass, and (ii) ii) The synchronization processing determines whether the handover candidate signal satisfies specified conditions based on a correlation value between information contained in the handover candidate signal that has passed through the tuner unit and known information. When it is determined that the handover candidate signal satisfies the specified conditions, the handover control unit outputs a handover execution signal. Upon obtaining the handover execution signal, the synchronization processing unit, the first transmission path estimation unit, the second transmission path estimation unit, the weight calculation unit, and the weighting unit switch the signal to be processed from the transmission signal to the handover candidate signal.

[0105] This allows for continuous reduction of the influence of interference components in both the desired signal and the handover candidate signal during handover, regardless of the handover candidate signal type. Consequently, the received SINR can be improved.

[0106] Alternatively, the signal processing device may further include: a tuner unit for passing a signal of a currently set first frequency band among signals received by the antenna for vertically polarized waves and the antenna for horizontally polarized waves; a synchronization processing unit for performing synchronization processing on the vertical signal and the horizontal signal that have passed through the tuner unit; and a handover control unit for indicating a handover candidate signal having at least one of a frequency and a polarization wave different from that of the transmitted signal, and when the handover candidate signal is indicated, (i) the tuner unit switches the frequency band for passing the signal to the first frequency band and the frequency band for passing the signal in a time-sharing manner The second frequency band through which the signal passes, and (ii) the synchronization processing determines whether the handover candidate signal satisfies a prescribed condition based on a correlation value between information contained in the handover candidate signal that has passed the tuner unit and known information, and when it is determined that the handover candidate signal satisfies the prescribed condition, the handover control unit outputs a handover execution signal, and the synchronization processing unit, the first transmission path estimation unit, the second transmission path estimation unit, the weight calculation unit and the weighting unit switch the signal to be processed from the transmission signal to the handover candidate signal when the handover execution signal is obtained.

[0107] This allows for all handover candidate signals to be reduced in a time-division manner during handover, regardless of the type of signal being the handover candidate signal. Consequently, the received SINR can be improved.

[0108] Alternatively, the signal processing device may further include: an antenna control unit that changes the orientation of the polarization plane of the signal received by the antenna for the vertically polarized wave and the antenna for the horizontally polarized wave, and the antenna control unit changes the orientation of the polarization plane based on the first weight and the second weight calculated by the weight calculation unit.

[0109] This can further reduce the influence of interference components and further improve the received SINR.

[0110] Furthermore, a moving object according to one aspect of the present disclosure includes the above-mentioned signal processing device, the vertically polarized wave antenna, and the horizontally polarized wave antenna.

[0111] This improves the received SNR, which is degraded by the polarization plane shifting from the optimal point, even when the polarization of the transmission signal changes moment by moment due to fluctuations such as roll and yaw in a moving object such as an aircraft. Furthermore, the received SINR can be improved.

[0112] Hereinafter, embodiments will be described in detail with reference to the drawings.

[0113] In addition, the embodiments described below all show general or specific examples. The numerical values, shapes, materials, structural elements, configuration positions and connection methods of structural elements, steps, the order of steps, etc. shown in the following embodiments are examples and are not intended to limit the present disclosure. In addition, among the structural elements in the following embodiments, the structural elements that are not recorded in the independent claims representing the highest concept are described as arbitrary structural elements. In addition, each figure is a schematic diagram and is not necessarily a strict illustration. In addition, in each figure, the same reference numerals are given to the same components.

[0114] (Implementation Method 1)

[0115] Figure 1 This is a diagram showing an example of the configuration of the communication system in Embodiment 1.

[0116] The communication system includes a satellite 3000 that transmits a satellite signal and a communication device 100 that receives the satellite signal.

[0117] like Figure 1 As shown, satellite 3000 is equipped with antenna 3010. Antenna 3010 supports two orthogonal polarizations (V polarization and H polarization). Therefore, satellite 3000 transmits and receives using a multi-spot beam using antenna 3010, that is, a multi-spot beam that repeats (4 colors) four-spot beams using the two orthogonal polarizations for each of the two frequency bands.

[0118] In addition, if Figure 1 As shown, an antenna 2010 is mounted on aircraft 2000 and is connected to communication device 100. Antenna 2010 supports two orthogonal polarizations (V polarization and H polarization). Furthermore, in this embodiment, a V polarization satellite signal is transmitted as a beam from satellite 3000 to the location of aircraft 2000. Communication device 100 receives the V polarization satellite signal transmitted from satellite 3000 using antenna 2010.

[0119] Figure 2 This figure shows the frame structure of the DVB-S2X standard (non-patent document 4) transmitted from the antenna 3010 of the satellite 3000. Each frame consists of a 90-symbol PL HEADER and a 64800-bit or 16200-bit LDPC coded frame. The PL HEADER has 90 symbols modulated by π / 2 BPSK and consists of a known bit pattern (18D2E82 HEX) and a 26-symbol SOF and a 64-symbol PLSCODE. An LDPC coded frame consists of S (S is an integer greater than or equal to 1) time slots, where the value of S varies depending on the modulation scheme. Furthermore, one time slot contains 90 symbols.

[0120] Figure 3 This diagram shows an example of the configuration of a communication device 100 mounted on aircraft 2000. The communication device 100 includes a tuner unit 110, a synchronization processing unit 130, a polarization signal processing unit 140, an FEC (Forward Error Correction) decoding unit 150, and a reference signal generator 155. Furthermore, the communication device 100 includes an A / D converter 120V for V polarization and an A / D converter 120H for H polarization. Furthermore, components within the communication device 100 other than the tuner unit 110 and the reference signal generator 155 may be configured as an integrated circuit 105.

[0121] Next, the operation of the communication device 100 will be described.

[0122] The two polarized wave signals received by the antenna 2010 are input to the tuner unit 110 as signals in the IF (Intermediate Frequency) band (also referred to as input IF signals).

[0123] Figure 4 (a) and (b) are diagrams showing an example of the frequency spectrum of the input IF signal. Figure 4 As shown, the input IF signal for V polarization is input in the frequency band of 950 to 1450 MHz, and the input IF signal for H polarization is input in the frequency band of 1650 to 2150 MHz. That is, the input IF signal for H polarization is input at a frequency 700 MHz higher than the input IF signal for V polarization. Furthermore, as described in the problem to be solved by the present disclosure, although aircraft 2000 calculates the polarization angle based on the positional relationship between the satellite and the body of aircraft 2000 (i.e., latitude and longitude information) and mechanically or electronically changes the polarization plane of antenna 2010, it is impossible to achieve a strict optimal point.

[0124] Figure 5 110 is a diagram showing an example of the configuration of the tuner unit 110. The tuner unit 110 includes down-converters 111 and 113, a reference signal generator 115, and a tuning signal generator 117.

[0125] exist Figure 5 In the tuner section 110, the reference signal generating section 115 generates a 700 MHz reference signal. The down-converting section 111 converts Figure 4The input IF signal shown in (a) is multiplied by the 700MHz reference signal, and the signal of the H polarized wave that is down-converted to 950-1450MHz is extracted by the BPF (Band Pass Filter). The tuning signal generating unit 117 generates a tuning signal whose center frequency is the same as the tuned frequency band among the signals in the 950-1450MHz range. The down-converting unit 113 converts Figure 4 The input IF signal shown in (a) and the signal output from the down-converter 111 are multiplied by the tuning signal, respectively, and the V polarization wave and H polarization wave signals down-converted to the baseband are extracted by the LPF (Low Pass Filter) and output as the tuned V signal and the tuned H signal.

[0126] Furthermore, in this embodiment, as described above, a V-polarized signal is transmitted as a beam from satellite 3000 to the location of aircraft 2000. Communication device 100 then receives the V-polarized signal transmitted from satellite 3000 using antenna 2010. Therefore, tuner unit 110 extracts and outputs a tuned V signal from the V-polarized signal received by the V-polarized antenna within antenna 2010, and extracts and outputs a tuned H signal from the V-polarized signal received by the H-polarized antenna within antenna 2010. In this case, down-conversion unit 111 of tuner unit 110 down-converts only signals in the 1650-2150 MHz band within the input IF signal.

[0127] Next, if Figure 3 As shown, the 10 MHz reference signal generated by the reference signal generator 155 is input to the integrated circuit 105. The V-polarized A / D converter 120V converts the tuned V signal from an analog signal to a digital signal. As a result, a tuned digital signal of V polarization is output. The H-polarized A / D converter 120H converts the tuned H signal from an analog signal to a digital signal. As a result, a tuned digital signal of H polarization is output.

[0128] Figure 6This diagram shows an example of the configuration of the synchronization processing unit 130. The synchronization processing unit 130 includes a coarse frequency synchronization processing unit 131V for V-polarized waves, a clock synchronization processing unit 132V, a frame synchronization processing unit 133V, a fine frequency synchronization processing unit 134V, a phase synchronization processing unit 135V, an amplitude control unit 136V, and a digital phase synchronization processing unit 137V. Furthermore, the synchronization processing unit 130 includes a coarse frequency synchronization processing unit 131H for H-polarized waves, a clock synchronization processing unit 132H, a frame synchronization processing unit 133H, a fine frequency synchronization processing unit 134H, a phase synchronization processing unit 135H, an amplitude control unit 136H, and a digital phase synchronization processing unit 137H. In this disclosure, among the reference numerals assigned to various components, "V" indicates that the component is for V-polarized waves, and "H" indicates that the component is for H-polarized waves. Furthermore, in this disclosure, when "H" or "V" is omitted from a reference symbol, the reference symbol indicates a component for either or both V-polarized waves and H-polarized waves. For example, "coarse frequency synchronization processing unit 131" indicates either or both coarse frequency synchronization processing unit 131V and coarse frequency synchronization processing unit 131H.

[0129] The synchronization processing unit 130 performs synchronization processing on the tuned V signal and tuned H signal, which have been converted to digital form. The synchronization processing unit 130 then outputs the tuned V signal after synchronization processing as a V signal or a synchronized signal, and outputs the tuned H signal after synchronization processing as an H signal or a synchronized signal. This basic operation complies with Annex C of Non-Patent Document 5, so the following description will focus only on the characteristic operations of this embodiment.

[0130] Figure 5 Tuner section 110 uses a 700 MHz reference signal generated independently of the 10 MHz reference signal used by synchronization processing section 130 to down-convert the H-polarized signal to a frequency range of 950 to 1450 MHz. Therefore, if synchronization processing section 130 were to independently perform synchronization processing on the tuned V signal and the tuned H signal output by tuner section 110, frequency and phase deviations would occur between the V and H signals output from synchronization processing section 130. Therefore, synchronization processing section 130 performs PLL (Phase Locked Loop) or feedforward control to minimize the frequency difference between the polarized waves after synchronization by precision frequency synchronization processing section 134. Furthermore, synchronization processing section 130 performs PLL or feedforward control to minimize the phase difference between the polarized waves after synchronization by phase synchronization processing section 135.

[0131] Or you can also Figure 5As shown, the 10 MHz reference signal generated by the reference signal generating unit 155 is input to the tuner unit 110, and the reference signal generating unit 115 uses the 10 MHz reference signal to generate a 700 MHz reference signal. Alternatively, Figure 4 As shown in (b), tuner section 110 extracts the 10 MHz reference signal generated by reference signal generator 155 and multiplexed with the input IF signal. Reference signal generator 115 uses this 10 MHz reference signal to generate a 700 MHz reference signal. In these cases, if synchronization processing section 130 independently synchronizes the two tuned V and H signals output by tuner section 110, only a phase deviation will occur between the V and H signals output by synchronization processing section 130. Therefore, synchronization processing section 130 performs PLL or feedforward control to ensure that the phase difference between the polarized waves synchronized by phase synchronization processing section 135 is zero.

[0132] As described above, the V-polarized and H-polarized tuned digital signals synchronized by the synchronization processing section 130 are input to the polarization signal processing section 140 as synchronized signals (ie, V signal and H signal).

[0133] Figure 7 This diagram shows an example of the configuration of the polarization signal processing unit 140. The polarization signal processing unit 140 includes a weight calculation unit 170 and a weighting unit 175. Furthermore, the polarization signal processing unit 140 includes a buffer 161V and a transmission path estimation unit 165V for V polarization, and a buffer 161H and a transmission path estimation unit 165H for H polarization.

[0134] Figure 8 : is a diagram showing an example of the configuration of the transmission path estimation unit 165. Figure 8 The configuration of the transmission path estimation unit 165 shown is the configuration of each of the transmission path estimation units 165V and 165H.

[0135] Transmission path estimation unit 165 includes 26 delay elements 181-1 to 181-26, 26 multipliers 182-1 to 182-26, and a normalization average processing unit 183. In this embodiment, the 26 delay elements 181-1 to 181-26 are also referred to as delay elements 181, and the 26 multipliers 182-1 to 182-26 are also referred to as multipliers 182.

[0136] exist Figure 8 In the transmission path estimation unit 165, at the timing when the 26 symbols of SOF are stored in the 26 delay elements 181, the 26 multipliers 182 perform multiplication between the outputs of the 26 delay elements 181 and the 26 coefficients C1 to C26 Multiply the respective complex numbers. 26 coefficients C1 to C 26 Yes Figure 2 The known bit pattern shown (18D2E82 HEX ) is the complex conjugate number of the symbol obtained by performing π / 2BPSK modulation on each bit of the signal. The normalization averaging processing unit 183 performs averaging processing on the outputs of the 26 multipliers 182 and outputs the normalized value as the transmission path estimation value. In addition, when there is no error at all in the 26 symbols of the SOF input to the transmission path estimation unit 165, the transmission path estimation unit 165 performs processing to make the output 1 as the above-mentioned normalization. That is, the transmission path estimation unit 165 performs the 26 symbols of the SOF included in the input synchronized signal and the known bit pattern (18D2E82 HEX ) are modulated with π / 2BPSK to obtain the correlation processing between the 26 symbols.

[0137] Figure 7 The weight calculation unit 170 uses Figure 8 The transmission path estimation values ​​outputted by the transmission path estimation units 165V and 165H are calculated as follows: MMSE (Minimum Mean Square Error) weight w = [w ＿V , w ＿H ] T . [·] T Represents the transpose of a matrix.

[0138] w=h H (hh H +σ 2 I) －1 ...Formula (1)

[0139] Here, h ＿V and h ＿H are the transmission path estimation values ​​of the signals received by the V-polarized wave antenna and the H-polarized wave antenna of the antenna 2010, respectively. The h in equation (1) is h=[h ＿V , h ＿H ] T .in addition,[·] H is the Hermitian transpose of the matrix, σ 2 is the variance of the received noise, and I is the identity matrix.

[0140] If σ is set 2 =0, w becomes the weight of ZF (Zero forcing).

[0141] When interference components are present in the received signal received via the antenna 2010, the estimated transmission path values ​​corresponding to the interference components for the V-polarized wave and H-polarized wave antennas are respectively set to h. ＿VU and h ＿HU , and set it to h ＿U =[h ＿VU , h ＿HU ] T , then the MMSE weight w is calculated by formula (2).

[0142] w=h H (hh H +h ＿U h ＿U H +σ 2 I) －1 ...Formula (2)

[0143] Figure 7 The weighting unit 175 uses the weight w output from the weight calculation unit 170 ＿V and w ＿H MMSE weighting is performed as shown in the following equation (3), and the resulting V-polarized wave signal x is output. ＿V .

[0144] x ＿V =w ＿V ·y ＿V +w ＿H ·y ＿H ...Formula (3)

[0145] Here, y ＿V This is a signal delayed by the buffer 161V among the V-polarized synchronously processed signals input to the polarization signal processing section 140, and is a signal delayed by an amount corresponding to the processing time in the transmission path estimation section 165V and the weight calculation section 170. ＿H This is the signal delayed by buffer 161H from among the synchronously processed H-polarized signals input to polarization signal processing section 140, and is the signal obtained by delaying it by an amount corresponding to the processing time in transmission path estimation section 165H and weight calculation section 170. As shown in equations (1) to (3), weight calculation and weighting processing are processes for maximum ratio combining the synchronously processed V-polarized and H-polarized signals.

[0146] Next, if Figure 3 As shown, the FEC decoding unit 150 of the communication device 100 processes the polarization signal x V as the output of the polarization signal processing unit 140. ＿V , and perform forward error correction processing.

[0147] The above configuration prevents synchronization deviations corresponding to the V-polarized and H-polarized input IF signals input to communication device 100. Furthermore, by performing MMSE processing on the signals received by the dual-polarized antenna (i.e., antenna 2010), the received SNR (Signal to Noisepower Ratio) degraded by the deviation of the polarization plane from the optimal point can be improved. Furthermore, the signal from an adjacent beam using the same frequency but a different polarization as the beam at the location of aircraft 2000 is attenuated by an amount corresponding to the XPD ratio (Cross Polar Discrimination) and becomes an interference component. However, in this embodiment, the received SINR (Signal to Interference plus Noisepower Ratio) can be improved through MMSE processing. Furthermore, when the aircraft is flying at the edge of the beam, the signal from an adjacent beam using the same frequency and polarization as the beam at the location of aircraft 2000 also becomes an interference component and becomes larger. However, in this embodiment, the influence of the interference component can be reduced through MMSE processing, thereby improving the received SINR.

[0148] Modifications

[0149] For example, an unknown satellite signal using the same frequency may propagate as an interference wave to the aircraft 2000. In this case, since the transmission path estimation value h of the unknown satellite signal cannot be obtained, ＿U ,therefore Figure 7 The weight calculation unit 170 may also calculate the MMSE weight w using the following formula (2)' instead of formula (2).

[0150] w=h H (E[yy H ]) －1 ...Formula (2)'

[0151] Here, y in the formula (2)' is y=[y ＿V ,y ＿H ] T , E[·] is the expected value.

[0152] As a result, the influence of interference components due to unknown satellite signals can be reduced by MMSE processing, thereby improving the received SINR.

[0153] Here, the communication device 100 in the present embodiment and the modified example includes a signal processing device for receiving a signal transmitted from the satellite 3000. The signal processing device includes a polarization signal processing unit 140, for example.

[0154] That is, the signal processing device includes a transmission path estimation unit 165V as a first transmission path estimation unit, a transmission path estimation unit 165H as a second transmission path estimation unit, a weight calculation unit 170 , and a weighting unit 175 .

[0155] Transmission path estimation unit 165V estimates the first transmission path characteristic of the transmission signal using the vertical signal, among the vertical and horizontal signals obtained by receiving a transmission signal transmitted from satellite 3000, which is a transmitting device, using a vertically polarized antenna and a horizontally polarized antenna. The vertically polarized antenna and the horizontally polarized antenna are included in antenna 2010, for example. Transmission path estimation unit 165H estimates the second transmission path characteristic of the transmission signal using the horizontal signal.

[0156] The first transmission path characteristic is the characteristic of the transmission path for transmitting a transmission signal from a transmission device (e.g., satellite 3000) to an antenna for vertically polarized waves. Furthermore, the second transmission path characteristic is the characteristic of the transmission path for transmitting a transmission signal from the transmission device to an antenna for horizontally polarized waves. For example, if a transmission signal is transmitted as a vertically polarized wave, and the polarization angles of the vertically polarized wave antenna and the horizontally polarized wave antenna deviate relative to the vertically polarized wave, a portion of the transmission signal is received by the horizontally polarized wave antenna. Therefore, for example, 80% of the signal components of the transmission signal are contained in the vertical signal, and the remaining 20% ​​are contained in the horizontal signal. Alternatively, the first transmission path characteristic may represent the proportion of the signal contained in the vertical signal within the transmission signal, and the second transmission path characteristic may represent the proportion of the signal contained in the horizontal signal within the transmission signal. Alternatively, the first and second transmission path characteristics may represent the deviation in polarization angle relative to the transmission signal, that is, the deviation in polarization angle of the vertically polarized wave antenna and the horizontally polarized wave antenna. Furthermore, the first and second transmission path characteristics may also include the attenuation characteristics of the transmission signal. The attenuation characteristic may also be the attenuation or attenuation rate of the transmission signal caused by the transmission distance of the transmission signal transmitted from the transmitting device and received by the antenna. Alternatively, the attenuation characteristic may be the attenuation or attenuation rate of the transmission signal caused by the state of the transmission path of the transmission signal, such as water vapor in the atmosphere. Furthermore, in this embodiment, the first and second transmission path characteristics are determined, for example, as the aforementioned transmission path estimated values.

[0157] The weight calculation unit 170 uses the first transmission path characteristic and the second transmission path characteristic to calculate the first weight corresponding to the vertical signal and the second weight corresponding to the horizontal signal. The weighting unit 175 uses the first weight and the second weight to perform weighted addition on the vertical signal and the horizontal signal. For example, the first weight and the second weight are MMSE weights, and through weighted addition, the vertical signal and the horizontal signal are combined in a maximum ratio. In addition, the vertical signal is, for example, the V signal mentioned above, but any signal can be obtained as long as it is a signal obtained by an antenna for V polarization. Similarly, the horizontal signal is, for example, the H signal mentioned above, but any signal can be obtained as long as it is a signal obtained by an antenna for H polarization.

[0158] Figure 9 This is a flowchart showing an example of the processing operation of the signal processing device in the first embodiment.

[0159] The signal processing device first estimates the first transmission path characteristic of the transmission signal using the vertical signal (step S101) from the vertical signal and the horizontal signal obtained by receiving the transmission signal transmitted from the transmission device using one of the vertical polarization wave and the horizontal polarization wave using the vertical polarization wave antenna and the horizontal polarization wave antenna. Next, the signal processing device estimates the second transmission path characteristic of the transmission signal using the horizontal signal (step S102). Next, the signal processing device calculates the first weight corresponding to the vertical signal and the second weight corresponding to the horizontal signal using the first transmission path characteristic and the second transmission path characteristic (step S103). Then, the signal processing device performs weighted addition on the vertical signal and the horizontal signal using the first weight and the second weight (step S104). In addition, the processing performed in steps S101 to S104 is performed, for example, by the polarization wave signal processing unit 140.

[0160] As described above, in the signal processing device and signal processing method of this embodiment, to receive a signal transmitted from a transmitting device such as a satellite, not only the signal obtained from an antenna corresponding to the polarization of the signal is used, but also the signal obtained from an antenna corresponding to a polarization orthogonal to the polarization of the signal. In other words, both vertical and horizontal signals are used. Furthermore, these vertical and horizontal signals are weighted and added using weights corresponding to the characteristics of the respective transmission paths. Therefore, if the weights are, for example, MMSE weights, even if the polarization of the transmitted signal changes moment by moment, the received SNR, which is degraded due to the deviation of the polarization plane from the optimal point, can be improved. Furthermore, the received SINR can also be improved.

[0161] The signal processing device may further include a synchronization processing unit 130 that performs synchronization processing on the vertical signal and the horizontal signal, respectively. In this case, the transmission path estimation unit 165V and the transmission path estimation unit 165H use the synchronized vertical and horizontal signals to estimate the first and second transmission path characteristics. Furthermore, the weighting unit 175 performs weighted addition on the synchronized vertical and horizontal signals. The synchronization processing unit 130 includes a first synchronization processing unit that performs synchronization processing on the vertical signal and a second synchronization processing unit that performs synchronization processing on the horizontal signal. The first and second synchronization processing units cooperate to bring the frequency and phase differences between the vertical and horizontal signals close to zero. For example, the first synchronization processing unit includes a coarse frequency synchronization processing unit 131V, a clock synchronization processing unit 132V, a frame synchronization processing unit 133V, a fine frequency synchronization processing unit 134V, a phase synchronization processing unit 135V, an amplitude control unit 136V, and a digital phase synchronization processing unit 137V. The second synchronization processing unit includes a coarse frequency synchronization processing unit 131H, a clock synchronization processing unit 132H, a frame synchronization processing unit 133H, a fine frequency synchronization processing unit 134H, a phase synchronization processing unit 135H, an amplitude control unit 136H, and a digital phase synchronization processing unit 137H. Furthermore, a fine frequency synchronization processing unit 134V cooperates with the fine frequency synchronization processing unit 134H, and a phase synchronization processing unit 135V cooperates with the phase synchronization processing unit 135H. Specifically, during the cooperation between the fine frequency synchronization processing units 134V and 134H, the fine frequency synchronization processing unit 134V transmits information indicating the frequency of the vertical signal to the fine frequency synchronization processing unit 134H. Conversely, the fine frequency synchronization processing unit 134H transmits information indicating the frequency of the horizontal signal to the fine frequency synchronization processing unit 134V. In cooperation with the phase synchronization processing unit 135V, the phase synchronization processing unit 135H transmits information indicating the phase of the vertical signal to the phase synchronization processing unit 135H. Conversely, the phase synchronization processing unit 135H transmits information indicating the phase of the horizontal signal to the phase synchronization processing unit 135V.

[0162] Figure 10 This is a flowchart showing another example of the processing operation of the signal processing device in the first embodiment.

[0163] The signal processing device first performs synchronization processing on the vertical signal and the horizontal signal respectively (step S90). At this time, as described above, the first synchronization processing unit and the second synchronization processing unit cooperate with each other to make the frequency difference and phase difference between the vertical signal and the horizontal signal close to 0. Then, the signal processing device executes the steps including Figure 9 The processes of steps S101 to S104 shown are polarization signal processing (step S100).

[0164] Therefore, in the signal processing device and the signal processing method of the present embodiment, it is possible to suppress synchronization deviation corresponding to the input vertical signal and horizontal signal.

[0165] (Implementation Method 2)

[0166] Figure 11 This figure shows an example of the configuration of a communication device 200 according to Embodiment 2. Among the components of the communication device 200 according to this embodiment, components identical to those of the communication device 100 according to Embodiment 1 are denoted by the same reference numerals as those of the components of Embodiment 1, and detailed descriptions thereof are omitted.

[0167] In this embodiment, satellite signals are multiplexed and transmitted using V- and H-polarized waves within a single frequency band within the beam at the location of aircraft 2000. DVB-S2X frames are multiplexed and transmitted at slightly different timings between the V- and H-polarized waves. This offers the advantage of being able to use existing DVB-S2X-compliant modulators without modification.

[0168] Figure 11 The communication device 200 and Figure 3 Compared to the communication device 100 in the first embodiment shown, the polarization signal processing unit 140 and the FEC decoding unit 150 are replaced by a polarization signal processing unit 240 and an FEC decoding unit 250, respectively. Furthermore, the components of the communication device 200 other than the tuner unit 110 and the reference signal generating unit 155 may be configured as an integrated circuit 205.

[0169] Figure 12 2 is a diagram showing an example of the structure of the polarization signal processing unit 240. Figure 7 Compared with the polarization signal processing unit 140 in the first embodiment shown, the transmission path estimation units 165V and 165H, the weight calculation unit 170, and the weighting unit 175 are replaced by transmission path estimation units 265V and 265H, a weight calculation unit 270, and a weighting unit 275, respectively.

[0170] Figure 13 : is a diagram showing the structure of the transmission path estimation unit 265. Figure 13 The configuration of the transmission path estimation unit 265 shown is the configuration of each of the transmission path estimation units 265V and 265H.

[0171] The transmission path estimation unit 265 and Figure 8 Compared with the transmission path estimation unit 165 in the first embodiment shown, the normalization average processing unit 183 is replaced with a normalization average processing unit 283 .

[0172] Normalization average processing unit 283 and Figure 8 Similarly, the normalized average processing unit 183 in the embodiment 1 shown outputs a transmission path estimation value of a satellite signal (e.g., a V polarized wave signal) transmitted with a polarization wave corresponding to the received polarization wave of the system corresponding to the normalized average processing unit 283. In addition, the normalized average processing unit 283 monitors the normalized average processing result between timings separated by a certain degree of symbol period before and after the timing of performing the normalized average processing. Then, the normalized average processing unit 283 outputs the monitored peak value as a transmission path estimation value of a satellite signal (e.g., an H polarized wave signal) transmitted with a polarization wave orthogonal to the received polarization wave of the above-mentioned system. That is, the normalized average processing unit 283 of the transmission path estimation unit 265V outputs the transmission path estimation value h ＿VV and h ＿VH The normalized average processing unit 283 of the transmission path estimation unit 265H outputs the transmission path estimation value h ＿HV and h ＿HH .

[0173] Figure 12 The weight calculation unit 270 uses Figure 13 The transmission path estimation value output by the transmission path estimation unit 265 is used to calculate the MMSE weight matrix W as shown in the following equations (4) to (6).

[0174] [Number 1]

[0175]

[0176] [Number 2]

[0177]

[0178] [Number 3]

[0179]

[0180] Here, h ＿VV , h ＿VH , h ＿HV , h ＿HH They are: the transmission path estimation value of the signal obtained by receiving the satellite signal sent with V polarization waves by the V polarization wave antenna, the transmission path estimation value of the signal obtained by receiving the satellite signal sent with H polarization waves by the V polarization wave antenna, the transmission path estimation value of the signal obtained by receiving the satellite signal sent with V polarization waves by the H polarization wave antenna, and the transmission path estimation value of the signal obtained by receiving the satellite signal sent with H polarization waves by the H polarization wave antenna.

[0181] Figure 12The weighting unit 275 performs MMSE weighting processing using the weight matrix W output from the weight calculation unit 270, and outputs the resulting V-polarized wave signal x ＿V and H polarization wave signal x ＿H .

[0182] [Number 4]

[0183]

[0184] Here, y ＿V This is a signal delayed by the buffer 161V among the V-polarized synchronously processed signals input to the polarization signal processing section 240, and is a signal delayed by an amount corresponding to the processing time in the transmission path estimation section 265V and the weight calculation section 270. ＿H The signal obtained by delaying the H-polarized synchronously processed signal input to the polarization signal processing section 240 in the buffer 161H is also delayed by an amount corresponding to the processing time in the transmission path estimation section 265H and the weight calculation section 270. ＊ ＿V and y ＊ ＿H They are y ＿V and y ＿H The complex conjugate of .

[0185] Next, if Figure 11 As shown, the FEC decoding unit 250 of the communication device 200 processes the V polarization signal x which is the output of the polarization signal processing unit 240. ＿V and H polarization wave signal x ＿H , and forward error correction is performed on each of them. The signals after forward error correction are output by different systems, or are multiplexed according to a predetermined rule and output by a single system.

[0186] With the above configuration, this embodiment achieves the benefits of Embodiment 1 while also enabling the use of existing DVB-S2X-compliant modulators to receive satellite signals multiplexed and transmitted in a single band using V- and H-polarizations. While interference components may exist between the two polarizations during reception, this embodiment reduces the impact of these interference components and improves the received SINR by performing MMSE processing on the signals received by the dual-polarization antennas.

[0187] Modifications

[0188] Instead of slightly differentiating the transmission timing of the DVB-S2X frame between the V polarization wave and the H polarization wave, Figure 2 The known bit pattern of the 26-symbol SOF shown is (18D2E82HEX That is, the bit pattern of one side between the V polarization wave and the H polarization wave is set to "18D2E82 HEX ", change the other side to "18D2E82 HEX "Orthogonal bit patterns. This allows the timing of DVB-S2X frames to be consistent between V-polarized waves and H-polarized waves, and improves the accuracy of the transmission path estimation value for the satellite signal transmitted via each polarization, obtained by the transmission path estimation unit.

[0189] Figure 14 : is a diagram showing an example of the configuration of the transmission path estimation unit 267 in this modification. The polarization signal processing unit 240 of the communication device 200 in this modification includes transmission path estimation units 267V and 267H instead of the transmission path estimation units 265V and 265H described above. Figure 14 The configuration of the transmission path estimation unit 267 shown is the configuration of each of the transmission path estimation units 267V and 267H.

[0190] The transmission path estimation unit 267 and Figure 8 Compared to the transmission path estimation unit 165 in the first embodiment shown, 26 multipliers 182-1' to 182-26' are added, and another normalization average processing unit 183 is added. In this embodiment, the 26 multipliers 182-1' to 182-26' are also referred to as multipliers 182'. The 26 multipliers 182' perform the multiplication of the outputs of the 26 delay elements 181 with the 26 coefficients C1' to C 26 'Multiply each complex number. 26 coefficients C1' to C 26 'It is right Figure 2 The known bit pattern shown (18D2E82 HEX ) is the complex conjugate number of a symbol obtained by performing π / 2 BPSK modulation on each bit of the orthogonal known bit pattern. Therefore, the transmission path estimation unit 267 can obtain two transmission path estimation values ​​with high accuracy.

[0191] (Implementation 3)

[0192] Figure 15 This figure shows an example of the configuration of a communication device 300 in Embodiment 3. Among the components of the communication device 300 in this embodiment, components identical to those of the communication device in Embodiment 1 or 2 are denoted by the same reference numerals as those of the components in Embodiment 1 or 2, and detailed descriptions thereof are omitted.

[0193] In this embodiment, the communication device 300 has an uplink transmission function, and uses the MMSE weight used in downlink reception as a weight in transmission.

[0194] Figure 15 The communication device 300 and Figure 3 Compared to the communication device 100 in the first embodiment shown, the configuration is such that an uplink signal generator 301, a polarized wave transmission signal generator 302, and an IF transmission signal generator 303 are additionally provided. Furthermore, the units including the uplink signal generator 301 and the polarized wave transmission signal generator 302 in the communication device 300 may be configured as an integrated circuit 304.

[0195] exist Figure 15 In the communication device 300, the uplink signal generation unit 301 performs modulation and error correction coding on the input uplink transmission data and outputs the uplink transmission data. The uplink signal generation unit 301 performs this processing in accordance with the DVB-RCS2 standard (Non-Patent Document 6), for example.

[0196] The polarized wave transmission signal generating section 302 uses the MMSE weights (w in the above equations (1) and (2)) used in downlink reception. ＿V and w ＿H ), the weighted processing is performed as follows (8) and (9), and the resulting V-polarized wave transmission baseband signal z is output. ＿V and H polarization waves to transmit baseband signals z ＿H .

[0197] z ＿V =w ＿V ·u...Formula (8)

[0198] z ＿H =w ＿H ·u...Formula (9)

[0199] Here, u is an output signal from the uplink signal generating unit 301 .

[0200] Figure 16 3 is a diagram showing an example of the configuration of the IF transmission signal generating section 303. The IF transmission signal generating section 303 includes up-converters 305 and 306, an adder 307, a tuning signal generating section 308, and a reference signal generating section 309.

[0201] exist Figure 16In the IF transmission signal generating section 303, the tuning signal generating section 308 generates a tuning signal with the same center frequency as the frequency position to be transmitted. The up-converting section 305 multiplies the two signals output from the polarization wave transmission signal generating section 302 by the tuning signal respectively, and extracts the up-converted V polarization wave signal and H polarization wave signal by each BPF and outputs them. The reference signal generating section 309 generates a 700MHz reference signal, and the up-converting section 306 multiplies the H polarization wave signal output from the up-converting section 305 by the 700MHz reference signal, and extracts the up-converted H polarization wave signal by the BPF and outputs it. Alternatively, it can also be as follows Figure 16 As shown, the reference signal generating unit 309 generates a 700 MHz reference signal using the 10 MHz reference signal generated by the reference signal generating unit 155. Alternatively, Figure 4 As shown in (b), the IF transmission signal generating section 303 extracts the 10 MHz reference signal generated by the reference signal generating section 155 and multiplexed with the input IF signal, and the reference signal generating section 309 generates a 700 MHz reference signal using the 10 MHz reference signal.

[0202] The adder 307 adds the V polarization signal output from the up-converter 305 and the H polarization signal output from the up-converter 306 and outputs the added signal as an IF signal to the output IF signal. Figure 1 The output IF signals of the V polarization wave and the H polarization wave output to the antenna 2010 are respectively output at Figure 4 The frequency difference between the two polarized waves is 700MHz. Antenna 2010 converts the output IF signal into an RF signal, amplifies the power, and transmits the V polarized wave and the H polarized wave RF signal to the antenna. Figure 1 Sent by 3000 satellites.

[0203] As described above, in this embodiment, communication device 300 has an uplink transmission function and utilizes the MMSE weights used for downlink reception as transmission weights. This allows the transmission plane of polarization of aircraft 2000 to be aligned with the reception plane of polarization of satellite 3000, thereby improving the received SINR at satellite 3000.

[0204] Modifications

[0205] When the communication device 200 of Embodiment 2 has an uplink transmission function, the MMSE weights used during downlink reception can also be used as weights during transmission, as in this embodiment. In other words, the communication device of this variation is a device that combines the functions of the communication device 300 of Embodiment 3 with the communication device 200 of Embodiment 2.

[0206] Figure 17 This is a diagram showing an example of the configuration of a communication device 350 in this modification. Figure 17 The communication device 350 and Figure 11 Compared to the communication device 200 in the second embodiment shown, the configuration is such that an uplink signal generator 301, a polarized wave transmission signal generator 302, and an IF transmission signal generator 303 are additionally provided. Furthermore, the units including the uplink signal generator 301 and the polarized wave transmission signal generator 302 in the communication device 300 may be configured as an integrated circuit 304.

[0207] The polarized wave transmission signal generating section 302 uses the MMSE weights (w in the above equations (4) and (5)) used in downlink reception. ＿VV and w ＿HH ), and then weighted processing is performed as shown in equations (9a) and (10), and the resulting V-polarized wave transmission baseband signal z is output. ＿V and H polarization waves to transmit baseband signal z ＿H .

[0208] z ＿V =w ＿VV ·u……Formula (9a)

[0209] z ＿H =w ＿HH ·u...Formula (10)

[0210] Here, u is the output signal from the uplink signal generator 301. Thus, even when downlinking a satellite signal multiplexed and transmitted using V-polarized waves and H-polarized waves in a single band, the transmit polarization plane of the aircraft 2000 can be aligned with the receive polarization plane of the satellite 3000, thereby improving the receive SINR at the satellite 3000.

[0211] (Implementation 4)

[0212] Figure 18 This figure shows an example of the configuration of communication device 400 in Embodiment 4. Among the components of communication device 400 in this embodiment, components identical to those in the communication device of any of Embodiments 1 to 3 are denoted by the same reference numerals as those in that embodiment, and detailed descriptions are omitted. In this embodiment, a signal similar to the desired signal exists as an interference signal. Furthermore, the desired signal is a signal transmitted from satellite 3000 to the location of aircraft 2000.

[0213] Figure 18 The communication device 400 and Figure 3Compared to the communication device 100 in the first embodiment shown, the configuration is such that a polarization shifting unit 402 and a packet determination unit 403 are added, and the synchronization processing unit 130 is replaced with a synchronization processing unit 401. The packet determination unit 403 feeds back the packet determination result as a packet reception status to the polarization shifting unit 402. Furthermore, the components of the communication device 400 other than the tuner unit 110 and the reference signal generator 155 may be configured as an integrated circuit 405.

[0214] Figure 19 This diagram shows an example of the configuration of the synchronization processing unit 401. The synchronization processing unit 401 includes a frame synchronization processing unit 133V for the V-polarized wave side, a coarse frequency synchronization processing unit 431, a clock synchronization processing unit 432, a fine frequency synchronization processing unit 434, a phase synchronization processing unit 435, an amplitude control unit 136V, and a digital phase synchronization processing unit 437. Furthermore, the synchronization processing unit 401 includes a coarse frequency synchronization correction unit 441, a clock synchronization correction unit 442, a fine frequency synchronization correction unit 444, a phase synchronization correction unit 445, an amplitude control unit 136H, and a digital phase synchronization correction unit 447 for the H-polarized wave side.

[0215] That is, in the synchronization processing unit 401, Figure 6 Compared to the synchronization processing unit 130 of the illustrated first embodiment, the coarse frequency synchronization processing unit 131V, clock synchronization processing unit 132V, fine frequency synchronization processing unit 134V, phase synchronization processing unit 135V, and digital phase synchronization processing unit 137V on the V-polarization side are replaced by a coarse frequency synchronization processing unit 431, a clock synchronization processing unit 432, a fine frequency synchronization processing unit 434, a phase synchronization processing unit 435, and a digital phase synchronization processing unit 437, respectively. Furthermore, the coarse frequency synchronization processing unit 131H, clock synchronization processing unit 132H, a fine frequency synchronization processing unit 134H, a phase synchronization processing unit 135H, and a digital phase synchronization processing unit 137H on the H-polarization side are replaced by a coarse frequency synchronization correction unit 441, a clock synchronization correction unit 442, a fine frequency synchronization correction unit 444, a phase synchronization correction unit 445, and a digital phase synchronization correction unit 447, respectively. In the synchronization processing unit 401, each processing unit on the V-polarization side detects errors in frequency, clock, and phase as an error signal. Based on this detected error signal, it calculates and outputs a correction signal for synchronization processing. Each correction unit on the H-polarization side uses this correction signal to perform synchronization correction on the input signal.

[0216] Furthermore, the frame synchronization processing unit 133V outputs feedback information indicating the frame synchronization determination result. For example, similar to the transmission path estimation unit 165V, the frame synchronization processing unit 133V derives a correlation value as a transmission path estimation value. If the correlation value exceeds a threshold, the unit outputs feedback information indicating successful frame synchronization as the frame synchronization determination result. In this case, the transmission path estimation unit 165V may obtain the correlation value from the frame synchronization processing unit 133V rather than deriving it itself.

[0217] Figure 20 This figure shows an example of the configuration of the polarization shifting unit 402. The polarization shifting unit 402 includes a total of four multipliers 184-1 to 184-4 and two adders 406-1 and 406-2 for the V-polarized wave signal and the H-polarized wave signal. Furthermore, the polarization shifting unit 402 includes a coefficient generator 407. This coefficient generator 407 receives feedback information from the synchronization processing unit 401. Here, the polarization shifting unit 402 applies a polarization shift to the input V-polarized wave signal and the H-polarized wave signal (the V-polarized wave and the tuned digital signal of each V-polarized wave) according to the following equations (11) and (12).

[0218] [Number 5]

[0219]

[0220] [Number 6]

[0221]

[0222] Here, the elements c1, c2, c3, and c4 of the matrix C are generated by the coefficient generation unit 407. For example, when feedback information indicating the frame synchronization determination result is obtained from the synchronization processing unit 401, the coefficient generation unit 407 sets the matrix C as shown in the following equation (13). The coefficient generation unit 407 may then sequentially change the value of θ in equation (13) until feedback information indicating successful frame synchronization is obtained as the frame synchronization determination result.

[0223] [Number 7]

[0224]

[0225] Although the polarization shifting unit 402 can quickly obtain feedback information from the synchronization processing unit 401, it is difficult to determine whether the frame synchronization success indicated by this feedback information corresponds to the desired signal or the interference signal. Therefore, after frame synchronization is successful, the packet identification unit 403 may determine whether the stream output from the FEC decoding unit 150 is the desired signal or the interference signal based on, for example, the IP address contained in the stream or the NIT (Network Information Table) contained in the TS (Transport Stream). The packet identification unit 403 may then feed back the packet identification result, which is the result of this determination, to the polarization shifting unit 402. For example, if the packet identification result indicating that the stream is an interference signal is fed back to the polarization shifting unit 402, the polarization shifting unit 402 changes the value of θ in equation (13).

[0226] Alternatively, the frame synchronization determination result from the synchronization processing unit 401 may not be fed back to the polarization shifting unit 402 , and only the packet determination result from the packet determination unit 403 may be fed back to the polarization shifting unit 402 .

[0227] When the V-polarization side has a value of θ that increases the power of the desired signal or the interference signal, the accuracy of the synchronization process on the V-polarization side is improved, and thus the frame synchronization processing unit 133H on the H-polarization side is unnecessary.

[0228] With the above configuration, this embodiment achieves the advantages of Embodiment 1 by utilizing the polarization shift function, frame synchronization determination function, or packet discrimination function to distinguish the desired signal from the interference signal, even in the presence of an interference signal similar to the desired signal. Consequently, by performing MMSE processing corresponding to the desired signal using both polarization signals, the effects of interference components can be mitigated, thereby improving the received SINR.

[0229] The communication device 400 in this embodiment includes a signal processing device for receiving signals transmitted from the satellite 3000. This signal processing device includes, for example, a polarization shifting unit 402, a synchronization processing unit 401, and a polarization signal processing unit 140. The polarization shifting unit 402 applies an offset to the vertical signal and horizontal signal to be synchronized based on at least one of the results of synchronization processing by the synchronization processing unit 401 and information contained in the signal obtained through weighted addition. As a result, the synchronization processing unit 401 performs synchronization processing on the vertical signal and horizontal signal to which the offsets have been applied.

[0230] The synchronization result of the synchronization processing unit 401 is reported to the polarization shifting unit 402 as the aforementioned feedback information. The information contained in the signal obtained by weighted addition is, for example, the aforementioned IP address or NIT. This information is obtained by the packet identification unit 403, and the packet identification result based on this information is fed back to the polarization shifting unit 402.

[0231] Figure 21 This is a flowchart showing an example of the processing operation of the signal processing device in embodiment 4.

[0232] First, the signal processing device calculates a correction signal based on the vertical signal and uses this correction signal to perform synchronization processing correction on the vertical and horizontal signals (step S95). Furthermore, polarization signal processing is performed (step S100). If there is a signal to be processed next (step S201: Yes), the polarization shifting unit 402 of the signal processing device derives an offset for the vertical and horizontal signals to be processed next based on at least one of the results of the synchronization processing by the synchronization processing unit 401 and information contained in the signal obtained through weighted addition (step S202). Furthermore, the polarization shifting unit 402 applies the derived offset to the vertical and horizontal signals to be processed next (step S203).

[0233] Thus, in the signal processing device and signal processing method of this embodiment, even in the presence of an interference signal similar to the desired signal from the transmitting device, an offset can be applied to obtain the desired signal. Therefore, the desired signal and the interference signal can be distinguished, the influence of the interference component can be reduced, and the received SINR can be improved.

[0234] (Implementation 5)

[0235] Figure 22 This figure shows an example of the configuration of communication device 450 in Embodiment 5. Among the components of communication device 450 in this embodiment, components identical to those of the communication device in any of Embodiments 1 to 4 are denoted by the same reference numerals as those in that embodiment, and detailed descriptions thereof are omitted. In this embodiment, a signal similar to the desired signal exists as an interference signal.

[0236] Figure 22 The communication device 450 and Figure 3Compared to the communication device 100 in the first embodiment shown, the synchronization processing unit 130 and the polarization signal processing unit 140 are replaced by a synchronization processing unit 451 and a polarization signal processing unit 452, respectively. Furthermore, the components of the communication device 450 other than the tuner unit 110 and the reference signal generating unit 155 may be configured as an integrated circuit 455.

[0237] Figure 23 451 is a diagram showing an example of the configuration of the synchronization processing unit 451. Figure 6 Compared to the synchronization processing unit 130 of the first embodiment shown, the V-polarization-side frame synchronization processing unit 133V and the H-polarization-side frame synchronization processing unit 133H are replaced with frame synchronization processing units 453 and 454, respectively. The V-polarization-side and H-polarization-side frame synchronization processing units 453 and 454 collaborate to establish frame synchronization and generate a frame synchronization timing signal. The V-polarization-side frame synchronization processing unit 453 outputs the frame synchronization timing signal. At a timing different from the frame synchronization timing, at least one of the V-polarization-side and H-polarization-side frame synchronization processing units 453 and 454 detects whether the correlation value between the tuned digital signal and the known bit pattern of the SOF exceeds a threshold. In this case, the V-polarization-side frame synchronization processing unit 453 calculates the timing difference between the detected timing and the frame synchronization timing. If this timing difference is less than a predetermined value, the V-polarization-side frame synchronization processing unit 453 invalidates and outputs a weight update instruction.

[0238] Figure 24 4 is a diagram showing an example of the structure of the polarization signal processing unit 452. Figure 7 Compared to the polarization signal processing unit 140 of the first embodiment shown, the weight calculation unit 170 is replaced by a weight calculation unit 470. In the polarization signal processing unit 452, when the weight update instruction is invalid, the weight calculation unit 470 stops the MMSE weight update and holds the last calculated weight.

[0239] As described above, in this embodiment, when the reception timings of a desired signal and an interference signal similar to the desired signal are close to each other, the MMSE weight update is stopped, thereby reducing the influence of the interference signal.

[0240] (Implementation 6)

[0241] Figure 25 This figure shows an example of the configuration of a communication device 500 in Embodiment 6. Among the components of the communication device 500 in this embodiment, components identical to those of the communication device in any one of Embodiments 1 to 5 are denoted by the same reference numerals as those of the components in that embodiment 1 to 5, and detailed descriptions thereof are omitted.

[0242] Figure 25 The communication device 500 and Figure 3 Compared to the communication device 100 in the first embodiment shown, the synchronization processing unit 130 is replaced with a synchronization processing unit 530. Furthermore, the components of the communication device 500 other than the tuner unit 110 and the reference signal generator 155 may be configured as an integrated circuit 505. Furthermore, the synchronization processing unit 530 in this embodiment may also be applied to Embodiments 1 to 5.

[0243] Figure 26 : This is a diagram showing an example of the structure of the synchronization processing unit 530. The synchronization processing unit 530 includes a frame synchronization processing unit 541 on the V polarization wave side, a coarse frequency synchronization processing unit 131V, a clock synchronization processing unit 532V, a fine frequency synchronization processing unit 134V, a phase synchronization processing unit 135V, an amplitude control unit 536V, and a digital phase synchronization processing unit 137V. Furthermore, the synchronization processing unit 530 includes a frame synchronization processing unit 542 on the H polarization wave side, a coarse frequency synchronization processing unit 131H, a clock synchronization processing unit 532H, a fine frequency synchronization processing unit 134H, a phase synchronization processing unit 135H, an amplitude control unit 536H, and a digital phase synchronization processing unit 137H. That is, in the synchronization processing unit 530, Figure 6 Compared to the synchronization processing unit 130 of the first embodiment shown, the clock synchronization processing units 132V and 132H and the amplitude control units 136V and 136H are replaced by clock synchronization processing units 532V and 532H and amplitude control units 536V and 536H, respectively. Furthermore, the frame synchronization processing units 133V and 133H on the V-polarization side and the H-polarization side are replaced by frame synchronization processing units 541 and 542, respectively.

[0244] The clock synchronization processing units 532V and 532H do not independently perform clock synchronization processing, but rather work in coordination. Similarly, the amplitude control units 536V and 536H do not independently perform amplitude control, but rather work in coordination. For example, the clock synchronization processing units 532V and 532H coordinate clock synchronization processing by performing vector addition of the clock timing errors of the two polarizations. Alternatively, the amplitude control units 536V and 536H coordinate amplitude control by controlling the gains of the two polarizations to the same gain, thereby maintaining a constant power sum of the two polarizations.

[0245] The frame synchronization processing units 541 and 542 on the V-polarization side and the H-polarization side cooperate to establish frame synchronization and generate a frame synchronization timing signal. The frame synchronization processing unit 541 on the V-polarization side then outputs the generated frame synchronization timing signal. For example, the frame synchronization processing units 541 and 542 on the V-polarization side and the H-polarization side cooperate to establish frame synchronization by detecting whether the correlation value between the tuned digital signal on at least one of the V-polarization side and the H-polarization side and the known bit pattern of the SOF exceeds a threshold.

[0246] The above configuration can improve the accuracy of synchronization processing in this embodiment. The same effects can be obtained when applied to Embodiments 1 to 5.

[0247] The communication device 500 in this embodiment includes a signal processing device for receiving signals transmitted from the satellite 3000. This signal processing device includes, for example, a synchronization processing unit 530 and a polarization signal processing unit 140. The synchronization processing unit 530 includes a first synchronization processing unit and a second synchronization processing unit. In this embodiment, the first synchronization processing unit includes a coarse frequency synchronization processing unit 131V, a clock synchronization processing unit 532V, a frame synchronization processing unit 541, a fine frequency synchronization processing unit 134V, a phase synchronization processing unit 135V, an amplitude control unit 536V, and a digital phase synchronization processing unit 137V. The second synchronization processing unit includes a coarse frequency synchronization processing unit 131H, a clock synchronization processing unit 532H, a frame synchronization processing unit 542, a fine frequency synchronization processing unit 134H, a phase synchronization processing unit 135H, an amplitude control unit 536H, and a digital phase synchronization processing unit 137H. The first synchronization processing unit and the second synchronization processing unit cooperate with each other to reduce the clock timing error between the vertical and horizontal signals (e.g., to near zero) and maintain a constant power sum of the vertical and horizontal signals. Specifically, the clock synchronization processing unit 532V and the clock synchronization processing unit 532H cooperate with each other, and the amplitude control unit 536V and the amplitude control unit 536H cooperate with each other.

[0248] Figure 27 This is a flowchart showing an example of the processing operation of the signal processing device in embodiment 6.

[0249] During the synchronization process in the signal processing device, the first synchronization processing unit and the second synchronization processing unit cooperate to bring the clock timing error between the vertical signal and the horizontal signal close to zero (step S91). Furthermore, the first synchronization processing unit and the second synchronization processing unit cooperate to bring the frequency difference and phase difference between the vertical signal and the horizontal signal close to zero, respectively, and to maintain a constant power sum of the vertical and horizontal signals (step S92).

[0250] Therefore, in the signal processing device and the signal processing method according to the present embodiment, the accuracy of the synchronization processing can be improved.

[0251] (Implementation 7)

[0252] Figure 28 This diagram shows the location of pilot blocks within the DVB-S2X frame structure. A pilot block consists of 36 symbols, and one is inserted every 16 slots in an LDPC coded frame. This pilot block takes a unique value for each scramble ID.

[0253] Figure 29 This figure shows an example of the configuration of a communication device 600 in Embodiment 7. Among the components of the communication device 600 in this embodiment, components identical to those of the communication device in any one of Embodiments 1 to 6 are denoted by the same reference numerals as those of the components in that embodiment 1 to 6, and detailed descriptions thereof are omitted.

[0254] Figure 29 The communication device 600 and Figure 3 Compared to the communication device 100 in the first embodiment shown, the synchronization processing unit 130 and the polarization signal processing unit 140 are replaced with a synchronization processing unit 630 and a polarization signal processing unit 640, respectively. Furthermore, the components of the communication device 600, other than the tuner unit 110 and the reference signal generator 155, may be implemented as an integrated circuit 605. Furthermore, the synchronization processing unit 630 and the polarization signal processing unit 640 in this embodiment may also be applied to embodiments 1 to 6.

[0255] Figure 30 : is a diagram showing an example of the configuration of the synchronization processing unit 630. Figure 26 Compared with the synchronization processing unit 530 of the sixth embodiment shown, the frame synchronization processing units 541 and 542 on the V-polarization side and the H-polarization side are replaced with frame synchronization processing units 641 and 642 , respectively.

[0256] The frame synchronization processing units 641 and 642 on the V polarization side and the H polarization side cooperate to establish frame synchronization and generate a frame synchronization timing signal. Then, the frame synchronization processing unit 641 on the V polarization side outputs the generated frame synchronization timing signal. Here, the frame synchronization processing units 641 and 642 on the V polarization side and the H polarization side use not only the SOF but also the pilot block for frame synchronization. For example, the frame synchronization processing units 641 and 642 on the V polarization side and the H polarization side cooperate to establish frame synchronization by detecting that the correlation cumulative value between the tuned digital signal on at least one of the V polarization side and the H polarization side and the SOF and the pilot block exceeds a threshold. In addition, the correlation cumulative value is the cumulative value of (1) the correlation value between the tuned digital signal and the known bit pattern of the SOF, and (2) the correlation value between the tuned digital signal and the inherent value of each of N (N is an integer greater than 1) pilot blocks.

[0257] Furthermore, the number of pilot blocks included between adjacent SOFs varies depending on the modulation scheme of the time slot. Therefore, if only a predetermined number of pilot blocks following an SOF are used for frame synchronization, it is possible to avoid including correlation values ​​of two SOFs in the correlation accumulation value.

[0258] In addition, Figure 30 In the synchronization processing unit 630, processing units other than the frame synchronization processing units 641 and 642 may also perform processing using the pilot blocks.

[0259] Figure 31 1 is a diagram showing an example of the configuration of the polarization signal processing unit 640. Figure 7 Compared to the polarization signal processing unit 140 of the first embodiment shown in FIG. 1 , the transmission path estimation units 165V and 165H on the V-polarization side and the H-polarization side are replaced with transmission path estimation units 665V and 665H, respectively. Figure 31 In the polarization signal processing unit 640, the transmission path estimation units 665V and 665H calculate the transmission path estimation value using not only the SOF but also the pilot block. Specifically, the transmission path estimation units 665V and 665H calculate the aforementioned correlation cumulative value as the transmission path estimation value on the V-polarization side and the H-polarization side, respectively.

[0260] As described above, this embodiment uses not only SOFs but also pilot blocks for frame synchronization and transmission path estimation. This allows the received signal to be identified as interference, even when the interference signal is similar to the desired signal, as long as the scramble IDs are different. This improves the accuracy of synchronization and MMSE weight calculation. Applying this embodiment to Embodiments 1 to 6 also yields similar results.

[0261] (Implementation 8)

[0262] Figure 32 This diagram shows the structure of a super frame (SF) in the DVB-S2X standard. Each frame consists of a 270-symbol SOSF, a 450-symbol SFFI, and a 611,820-symbol format-specific frame, for a total of 612,540 symbols.

[0263] SOSF is composed of a 256-bit Walsh-Hadamard sequence and 14 bits of padding. Therefore, there are 256 types of sequences in SOSF, which are mutually orthogonal. In addition, in the Format-specific frame, a pilot block can be inserted after the data or header. The insertion interval of the pilot block and the length of the pilot block are variable according to the format of SF (0 to 4). In addition, the pilot block is also composed of a Walsh-Hadamard sequence like SOSF, so the pilot blocks composed of different Walsh-Hadamard sequences are mutually orthogonal. In addition, the Format-specific frame also contains Figure 2 SOF shown.

[0264] Figure 33 This figure shows an example of the configuration of a communication device 700 in Embodiment 8. Among the components of the communication device 700 in this embodiment, components identical to those of the communication device in any one of Embodiments 1 to 7 are denoted by the same reference numerals as those of the components in that embodiment 1 to 7, and detailed descriptions thereof are omitted.

[0265] Figure 33 The communication device 700 and Figure 3 Compared to the communication device 100 in the first embodiment shown, the synchronization processing unit 130 and the polarization signal processing unit 140 are replaced with a synchronization processing unit 730 and a polarization signal processing unit 740, respectively. Furthermore, the components of the communication device 700, other than the tuner unit 110 and the reference signal generator 155, can also be implemented as an integrated circuit 705. Furthermore, the synchronization processing unit 730 and the polarization signal processing unit 740 in this embodiment can also be applied to Embodiments 1 to 7.

[0266] Figure 34 : is a diagram showing an example of the configuration of the synchronization processing unit 730. Figure 26 Compared with the synchronization processing unit 530 of the sixth embodiment shown, the frame synchronization processing units 541 and 542 on the V-polarization side and the H-polarization side are replaced with frame synchronization processing units 741 and 742, respectively.

[0267] The frame synchronization processing units 741 and 742 on the V polarization side and the H polarization side cooperate to establish frame synchronization and generate a frame synchronization timing signal. Then, the frame synchronization processing unit 741 on the V polarization side outputs the generated frame synchronization timing signal. Here, the frame synchronization processing units 741 and 742 on the V polarization side and the H polarization side also use the SOSF and the pilot block for frame synchronization. For example, the frame synchronization processing units 741 and 742 on the V polarization side and the H polarization side cooperate to establish frame synchronization by detecting that the cumulative correlation value between the tuned digital signal on at least one of the V polarization side and the H polarization side and the SOSF, SOF and pilot block exceeds a threshold. In addition, the cumulative correlation value is the cumulative value of (1) the correlation value between the tuned digital signal and the known bit pattern of the SOSF, (2) the correlation value between the tuned digital signal and the known bit pattern of the SOF, and (3) the correlation value between the tuned digital signal and the inherent values ​​of each of N (N is an integer greater than 1) pilot blocks.

[0268] Furthermore, the number of pilot blocks included between adjacent SOFs varies depending on the modulation scheme of the time slot. Therefore, if only a predetermined number of pilot blocks following an SOF are used for frame synchronization, it is possible to avoid including correlation values ​​of two SOFs in the correlation accumulation value.

[0269] In addition, Figure 34 In the synchronization processing unit 730, processing units other than the frame synchronization processing units 741 and 742 may also perform processing using the SOSF and the pilot block.

[0270] Figure 35 FIG. 7 is a diagram showing an example of the configuration of the polarization signal processing unit 740. Figure 7 Compared to the polarization signal processing unit 140 of the first embodiment shown in FIG. 1 , the transmission path estimation units 165V and 165H on the V-polarization side and the H-polarization side are replaced with transmission path estimation units 765V and 765H, respectively. Figure 35 In the polarization signal processing unit 740, the transmission path estimation units 765V and 765H calculate the transmission path estimation value using not only the SOF but also the SOSF and the pilot block. Specifically, the transmission path estimation units 765V and 765H calculate the aforementioned correlation cumulative value as the transmission path estimation value on the V-polarization side and the H-polarization side, respectively.

[0271] As described above, this embodiment performs frame synchronization on the SOSF and pilot blocks that make up the DVB-S2X SF, leveraging their orthogonality. This allows for distinguishing whether the received signal is an interference signal or a desired signal, even when the interference signal is similar to the desired signal, improving synchronization accuracy. Similar effects can be achieved when this embodiment is applied to Embodiments 1 to 7.

[0272] (Implementation 9)

[0273] Figure 36 This figure shows an example of the configuration of a communication device 800 in Embodiment 9. Among the components of the communication device 800 in this embodiment, components identical to those of the communication device in any one of Embodiments 1 to 8 are denoted by the same reference numerals as those of the components in that embodiment 1 to 8, and detailed descriptions thereof are omitted.

[0274] Figure 36 The communication device 800 and Figure 3 Compared to the communication device 100 in the first embodiment shown, the synchronization processing unit 130 is replaced with a synchronization processing unit 830, and an error detection unit 860 is added. Furthermore, the components of the communication device 800 other than the tuner unit 110 and the reference signal generator 155 may be configured as an integrated circuit 805. Furthermore, the synchronization processing unit 830 and the error detection unit 860 in this embodiment may also be applied to embodiments 1 to 8.

[0275] The error detection unit 860 receives the output signal from the polarization signal processing unit 140 (also referred to as the polarization signal processed signal) and detects errors in the output signal. For example, the error detection unit 860 detects differences in frequency, phase, and other parameters between multiple symbols included in the output signal as errors. This error may also be the average value of a predetermined number of symbols. The error detection unit 860 then feeds error information indicating this error back to the synchronization processing unit 830.

[0276] Figure 37 This is a diagram showing an example of the configuration of the synchronization processing unit 830 . Figure 37 The synchronization processing unit 830 includes a coarse frequency synchronization processing unit 831V for V-polarized waves, a clock synchronization processing unit 832V, a frame synchronization processing unit 833V, a fine frequency synchronization processing unit 834V, a phase synchronization processing unit 835V, an amplitude control unit 836V, and a digital phase synchronization processing unit 837V. Furthermore, the synchronization processing unit 830 includes a coarse frequency synchronization processing unit 831H for H-polarized waves, a clock synchronization processing unit 832H, a frame synchronization processing unit 833H, a fine frequency synchronization processing unit 834H, a phase synchronization processing unit 835H, an amplitude control unit 836H, and a digital phase synchronization processing unit 837H.

[0277] In this disclosure, as described above, when "H" or "V" is omitted from a reference symbol, the reference symbol indicates a component for either or both V-polarized waves and H-polarized waves. For example, "coarse frequency synchronization processing unit 831" indicates either or both coarse frequency synchronization processing unit 831V and coarse frequency synchronization processing unit 831H.

[0278] The synchronization processing unit 830 performs synchronization processing on the tuned V signal and tuned H signal, which have been converted to digital form. The synchronization processing unit 830 then outputs the tuned V signal after synchronization processing as a V signal or a synchronized signal, and outputs the tuned H signal after synchronization processing as an H signal or a synchronized signal. This basic operation complies with Annex C of Non-Patent Document 5, so the following description will focus only on the characteristic operations of this embodiment.

[0279] In this embodiment, the error information fed back from the error detection unit 860 is input to each of the coarse frequency synchronization processing unit 831, the clock synchronization processing unit 832, the fine frequency synchronization processing unit 834, the phase synchronization processing unit 835, the amplitude control unit 836, and the digital phase synchronization processing unit 837 of the synchronization processing unit 830. Hereinafter, each of the synchronization processing units to which the error information is input is referred to as a parameter synchronization processing unit.

[0280] When performing synchronization processing for frequency or phase, the parameter synchronization processing unit detects an error based on the input polarization signal (i.e., the tuned digital signal) and uses this error for synchronization processing. In this embodiment, the parameter synchronization processing unit not only uses the error detected based on the input polarization signal for synchronization processing, but also adds this error to the error indicated by the error information fed back from the error detection unit 860 and uses this addition result for synchronization processing. In the output signal of the polarization signal processing unit 140, the effects of interference and noise are reduced by MMSE processing compared to the input polarization signal. Therefore, by also using error information based on this output signal, the parameter synchronization processing unit can perform more accurate error detection. As a result, the accuracy of the synchronization processing in each parameter synchronization processing unit can be improved. Examples of synchronization processing here include clock synchronization, coarse or fine frequency synchronization, phase synchronization, amplitude control, and digital phase synchronization.

[0281] Furthermore, the frame synchronization processing unit 833 in this embodiment obtains a polarization signal-processed signal. After the operation begins, the frame synchronization processing unit 833 uses the output signal from the clock synchronization processing unit 832 for processing. If the correlation value with the SOF is initially detected to exceed the threshold, the frame synchronization timing signal is output. The frame synchronization processing unit 833 then uses the polarization signal-processed signal to decode the PLSCODE following the SOF, obtaining information related to the MODCOD (modulation mode / coding rate) or the presence of a pilot signal, and detecting the number of symbols contained in the frame. This allows the frame synchronization processing unit 833 to detect the timing of the leading symbol of the next frame. In subsequent operations, the frame synchronization processing unit 833 can also use the polarization signal-processed signal.

[0282] As described above, in this embodiment, the accuracy of the synchronization processing can be improved by feeding back the error detected based on the signal that has completed polarization signal processing (the aforementioned polarization signal processed signal) to the synchronization processing unit 830. The same effect can be achieved when this embodiment is applied to Embodiments 1 to 8. Furthermore, in this embodiment, the communication device 800 includes an error detection unit 860, and the output signal from this error detection unit 860 is fed back to the synchronization processing unit 830. However, the communication device 800 may not include the error detection unit 860, and instead the polarization signal processed signal from the polarization signal processing unit 140 is fed back to each parameter synchronization processing unit of the synchronization processing unit 830. In this case, each parameter synchronization processing unit detects the error in the polarization signal processed signal using the error detection unit used in the synchronization processing. This allows error detection corresponding to the output of the polarization signal processing unit 140 to be performed with a reduced amount of computation.

[0283] (Implementation 10)

[0284] Figure 38 This figure shows an example of the configuration of a communication device 900 in Embodiment 10. Among the components of the communication device 900 in this embodiment, components identical to those of the communication device in any one of Embodiments 1 to 9 are denoted by the same reference numerals as those of the components in that embodiment 1 to 9, and detailed descriptions thereof are omitted.

[0285] Figure 38 The communication device 900 and Figure 3Compared to the communication device 100 in the first embodiment shown, an equalizer unit 970 is added. Furthermore, the components of the communication device 900 other than the tuner unit 110 and the reference signal generator 155 may be configured as an integrated circuit 905. Here, the equalizer unit 970 performs equalization processing, such as linear equalization using a transversal filter or nonlinear equalization using maximum likelihood sequence estimation (MLSE), on the output signal from the polarization signal processing unit 140.

[0286] As described above, in this embodiment, the influence of intersymbol interference can be reduced and the received SINR can be improved by performing equalization processing on the output signal from the polarization signal processing unit 140. In addition, the same effect can be obtained when this embodiment is applied to Embodiments 1 to 9.

[0287] <Variation 1>

[0288] Instead of performing the equalization process on the output signal from the polarization signal processing unit 140 , the equalization process may be performed on the output signal from the synchronization processing unit 130 .

[0289] Figure 39 This diagram shows an example of the configuration of a communication device 901 in Modification 1. In communication device 901, compared to communication device 900, equalization unit 970 is replaced with equalization unit 971, which is placed before, rather than after, polarization signal processing unit 140. Equalization unit 971 receives two input signals, compared to equalization unit 970, and performs equalization processing on each of the two input signals. Specifically, equalization unit 971 performs equalization processing on both the V-polarization synchronization-processed signal and the H-polarization synchronization-processed signal output from synchronization processing unit 130.

[0290] By performing symbol interference removal in advance on the signal to be processed by the polarization signal processing unit 140 in this manner, the improvement effect of the received SINR obtained by the MMSE processing in the polarization signal processing unit 140 can be further enhanced.

[0291] <Variation 2>

[0292] The equalization unit and the polarization signal processing unit may be combined.

[0293] Figure 40 1 is a diagram showing an example of the configuration of a communication device 902 in Modification 2. Compared to the communication device 900 , the communication device 902 has a configuration in which the polarization signal processing unit 140 and the equalization unit 970 are replaced with a polarization signal processing unit 940 .

[0294] Figure 41 It is a diagram showing an example of the configuration of the polarization signal processing unit 940 . Figure 41 The polarization signal processing unit 940 and Figure 7 Compared with the polarization signal processing unit 140 in the first embodiment shown, the weighting unit 175 is replaced with a weighting unit 975 . Figure 41 The weighting unit 975 uses the weight w of N symbols (N is a natural number greater than or equal to 2) output from the weight calculation unit 170. ＿V (t-N+1), w ＿V (t-N+2),……,w ＿V (t), and w ＿H (t-N+1), w ＿H (t-N+2),……,w ＿H (t) is subjected to MMSE weighting processing as shown in the following equation (14). The weighting unit 975 then outputs the V-polarized wave signal x as a result of the weighting processing. ＿V (t).

[0295] [Number 8]

[0296]

[0297] Here, y ＿V (t-N+1), y ＿V (t-N+2),……,y ＿V (t) is a signal of N symbols delayed by the buffer 161V among the V-polarized wave synchronization-processed signals input to the polarization signal processing unit 940. ＿H (t-N+1), y ＿H (t-N+2),……,y ＿H (t) is a signal of N symbols delayed by the buffer 161H among the H-polarized wave synchronization-processed signals input to the polarization signal processing section 940 . Figure 41 The polarization signal processing unit 940 shown performs MMSE weighting processing using N symbols of weight coefficients and N symbols of synchronized signals, and performs equalization processing within the polarization signal processing unit 940. The polarization signal processing unit 940 with such a configuration can also reduce the effects of intersymbol interference through equalization processing, similar to Embodiment 10 and Modification 1.

[0298] Here, the communication device in this embodiment and its variations includes a signal processing device for receiving signals transmitted from satellite 3000. This signal processing device includes, for example, a synchronization processing unit 130, a polarization signal processing unit, and an equalization unit. The equalization unit may also be the equalization unit 970 or 971 described above. Furthermore, the polarization signal processing unit may be the polarization signal processing unit 140 described above, or the polarization signal processing unit 940 that also functions as an equalization unit. The equalization unit performs equalization processing on the vertical and horizontal signals that have undergone synchronization processing, or on the signals obtained by weighted addition. For example, the equalization unit 971 performs equalization processing on the vertical and horizontal signals that have undergone synchronization processing, and the equalization unit 970 performs equalization processing on the signals obtained by weighted addition. Furthermore, the polarization signal processing unit 940 performs equalization processing on the vertical and horizontal signals that have undergone synchronization processing.

[0299] Figure 42 This is a flowchart showing an example of the processing operation of the signal processing device in embodiment 10.

[0300] The signal processing device first performs coordinated synchronization processing on the vertical and horizontal signals (step S90), and then performs polarization signal processing (step S100). Then, the equalization unit 970 of the signal processing device performs equalization processing on the signal obtained by weighted addition of the polarization signal processing (step S300).

[0301] Thus, in the signal processing device and signal processing method of this embodiment, the equalization process can reduce the influence of inter-symbol interference. In other words, the influence of delayed waves can be reduced. As a result, the received SINR can be improved.

[0302] (Implementation 11)

[0303] Figure 43 This figure shows an example of the configuration of communication device 1000 in Embodiment 11. Among the components of communication device 1000 in this embodiment, components identical to those of the communication device in any one of Embodiments 1 to 10 are denoted by the same reference numerals as those in that embodiment 1 to 10, and detailed descriptions thereof are omitted.

[0304] Figure 43 The communication device 1000 and Figure 25Compared to the communication device 500 in the sixth embodiment shown, the tuner unit 110, synchronization processing unit 530, and polarization signal processing unit 140 are replaced with a tuner unit 1010, a synchronization processing unit 1030, and a polarization signal processing unit 1040, respectively. Furthermore, a handover control unit 1080 is added. Furthermore, the components of the communication device 1000 other than the tuner unit 1010, the reference signal generation unit 155, and the handover control unit 1080 may be implemented as an integrated circuit 1005. Furthermore, the tuner unit 1010, synchronization processing unit 1030, polarization signal processing unit 1040, and handover control unit 1080 in this embodiment may also be applied to embodiments 1 to 10.

[0305] In this embodiment, handover control unit 1080 designates a signal with a frequency different from that of the current signal as a candidate handover signal. Furthermore, the current signal is a signal transmitted from satellite 3000 to the current location of aircraft 2000. Upon such designation, tuner unit 1010 tunes and outputs the signal with the designated frequency as the H-polarized reception signal. Furthermore, if a V-polarized signal with a frequency different from that of the current signal is designated as a candidate handover signal, tuner unit 1010 tunes and outputs the V-polarized signal with the designated frequency as the H-polarized reception signal.

[0306] Figure 44 This is a diagram showing an example of the configuration of the synchronization processing unit 1030 . Figure 44 The synchronization processing unit 1030 includes a coarse frequency synchronization processing unit 1031V for V-polarized waves, a clock synchronization processing unit 1032V, a frame synchronization processing unit 1041, a fine frequency synchronization processing unit 1034V, a phase synchronization processing unit 1035V, an amplitude control unit 1036V, and a digital phase synchronization processing unit 1037V. Furthermore, the synchronization processing unit 1030 includes a coarse frequency synchronization processing unit 1031H for H-polarized waves, a clock synchronization processing unit 1032H, a frame synchronization processing unit 1042, a fine frequency synchronization processing unit 1034H, a phase synchronization processing unit 1035H, an amplitude control unit 1036H, and a digital phase synchronization processing unit 1037H.

[0307] In this disclosure, as described above, when "H" or "V" is omitted from a reference symbol, the reference symbol indicates a component for either or both V-polarized waves and H-polarized waves. For example, "coarse frequency synchronization processing unit 1031" indicates either or both coarse frequency synchronization processing unit 1031V and coarse frequency synchronization processing unit 1031H.

[0308] The synchronization processing unit 1030 performs synchronization processing on the tuned V signal and tuned H signal, which have been converted to digital form. The synchronization processing unit 1030 then outputs the tuned V signal after synchronization processing as a V signal or a synchronized signal, and outputs the tuned H signal after synchronization processing as an H signal or a synchronized signal. This basic operation complies with Annex C of Non-Patent Document 5, so the following description will focus only on the characteristic operations of this embodiment.

[0309] In this embodiment, the handover information output from the handover control unit 1080 is input to each of the coarse frequency synchronization unit 1031, clock synchronization unit 1032, fine frequency synchronization unit 1034, phase synchronization unit 1035, amplitude control unit 1036, and digital phase synchronization unit 1037 of the synchronization processing unit 1030. The synchronization processing units to which the handover information is input are hereinafter referred to as parameter synchronization units. The handover information is information indicating the aforementioned handover candidate signals.

[0310] When the handover control unit 1080 indicates a signal with a frequency different from the current signal as a handover candidate signal, the parameter synchronization processing units of the synchronization processing unit 1030 independently perform synchronization processing. Specifically, the parameter synchronization processing units on the V-polarization side perform synchronization processing on the current received signal, while the parameter synchronization processing units on the H-polarization side perform synchronization processing on the received signal at the indicated frequency. The frame synchronization processing units 1041 and 1042 collaborate to output the frame synchronization detection results of the frame synchronization processing unit 1042 as handover candidate quality to the handover control unit 1080. The handover candidate quality is, for example, information indicating whether the correlation value between the H-polarization received signal (i.e., the tuned digital signal) and the known bit pattern of the SOF exceeds a threshold.

[0311] Figure 45 1040 is a diagram showing an example of the structure of the polarization signal processing unit 1040. Figure 45 In the polarization signal processing unit 1040, Figure 7 Compared to the polarization signal processing unit 140 in the first embodiment shown, the weighting unit 175 is replaced with a weighting unit 1075. This weighting unit 1075 receives the handover information. Upon receiving this handover information, weighting unit 1075 outputs the V-polarized signal after synchronization processing, which is output from buffer 161V, as is. In other words, the polarization signal processing unit 1040 does not perform MMSE weighting during handover.

[0312] If the handover candidate quality outputted from the synchronization processing unit 1030 is sufficient, the handover control unit 1080 outputs a handover execution signal to formally execute the handover. Furthermore, the handover candidate quality is considered sufficient when the correlation value between the H-polarized received signal (i.e., the tuned digital signal) and the known bit pattern of the SOF exceeds a threshold. The tuner unit 1010 then tunes the received signal of the handover target. Specifically, the tuner unit 1010 tunes the signal to the frequency specified by the handover control unit 1080 using both V-polarized and H-polarized signals. The synchronization processing unit 1030 and the polarized wave signal processing unit 1040 then perform the same processing as in Embodiment 6.

[0313] As described above, in this embodiment, when a handover occurs, information on the handover timing and the signal to be used after the handover is notified to the tuner unit 1010, the synchronization processing unit 1030, and the polarization signal processing unit 1040. This allows continuous reception of desired signals even during a handover.

[0314] The communication device 1000 in this embodiment includes a signal processing device for receiving signals transmitted from the satellite 3000. This signal processing device includes, for example, a synchronization processing unit 1030, a polarization signal processing unit 1040, and a handover control unit 1080. The handover control unit 1080 indicates a handover candidate signal having a frequency different from that of the transmission signal transmitted from the transmitting device, such as the satellite 3000. If a handover candidate signal is indicated, the weighting unit 1075 of the polarization signal processing unit 1040 does not perform weighted addition. Furthermore, the synchronization processing unit 1030 determines whether a received signal, obtained by receiving the signal using an antenna corresponding to a polarization different from that of the transmission signal, either the vertically polarized antenna or the horizontally polarized antenna, meets predetermined conditions. If the handover control unit 1080 determines that the received signal meets the predetermined conditions, it outputs a handover execution signal. Upon receiving this handover execution signal, the synchronization processing unit 1030 and the polarization signal processing unit 1040 switch the signal being processed from the transmission signal to the handover candidate signal. The predetermined condition may be a condition that the correlation value is greater than or equal to the threshold, or a condition that the error rate representing the result of the error correction processing by the FEC decoding unit 150 is less than or equal to the threshold. Furthermore, the determination of whether the handover candidate quality is sufficient is performed by determining whether the received signal satisfies the predetermined condition.

[0315] Figure 46 This is a flowchart showing an example of the processing actions of the signal processing device in embodiment 11.

[0316] First, the synchronization processing unit 1030 determines whether a handover candidate signal with a different frequency has been indicated (step S401). If not indicated (step S401: No), the synchronization processing unit 1030 performs coordinated synchronization processing on the vertical signal and the horizontal signal, as described above (step S90). Furthermore, the polarization signal processing unit 1040 performs polarization signal processing (step S100). On the other hand, if a handover candidate signal has been indicated (step S401: Yes), the weighting unit 1075 of the polarization signal processing unit 1040 does not perform weighted addition, and the synchronization processing unit 1030 performs synchronization processing on the vertical signal and the horizontal signal, respectively (step S90a). At this point, the synchronization processing unit 1030 determines the quality of the signal received by the vertical polarization antenna or the horizontal polarization antenna, whichever corresponds to a polarization different from the transmitted signal, as the quality of the handover candidate signal (step S402). The handover control unit 1080 then determines whether the determined quality satisfies the handover criteria (step S403). If the quality satisfies the criteria (step S403: Yes), the handover control unit 1080 instructs the synchronization processing unit 1030 and the polarization signal processing unit 1040 to switch the signal being processed from the aforementioned transmission signal to the handover candidate signal (step S404).

[0317] Therefore, in the signal processing apparatus and the signal processing method according to the present embodiment, even though, for example, the weighted addition of MMSE is suspended during handover, the handover can be appropriately performed.

[0318] (Implementation 12)

[0319] Figure 47 This figure shows an example of the configuration of a communication device 1100 in Embodiment 12. Among the components of the communication device 1100 in this embodiment, components identical to those of the communication device in any one of Embodiments 1 to 11 are denoted by the same reference numerals as those in that embodiment 1 to 11, and detailed descriptions thereof are omitted.

[0320] Figure 47 The communication device 1100 and Figure 22 Compared to the communication device 450 in the fifth embodiment shown, the synchronization processing unit 451 is replaced with a synchronization processing unit 1151, and a handover control unit 1180 is added. Furthermore, the components of the communication device 1100 other than the tuner unit 110, the reference signal generation unit 155, and the handover control unit 1180 may be configured as an integrated circuit 1155. Furthermore, the synchronization processing unit 1151 and the handover control unit 1180 in this embodiment may also be applied to embodiments 1 to 11.

[0321] In this embodiment, the handover control unit 1180 specifies a signal having the same frequency and a different polarization from the current signal as a handover candidate signal.

[0322] Figure 48 This is a diagram showing an example of the configuration of the synchronization processing unit 1151 . Figure 48 The synchronization processing unit 1151 and Figure 23 Compared to the synchronization processing unit 451 in the fifth embodiment shown, the frame synchronization processing units 453 and 454 are replaced with frame synchronization processing units 1153 and 1154, respectively. The frame synchronization processing units 1153 and 1154 receive handover information as input. Furthermore, the V-polarization-side frame synchronization processing unit 1153 and the H-polarization-side frame synchronization processing unit 1154 cooperate to output a weight update instruction to the polarization signal processing unit 1152 based on the frame synchronization positions of the two polarization signals. Furthermore, based on the input handover information (i.e., the handover candidate signal), the frame synchronization processing units 1153 and 1154 observe whether the correlation value of the SOF detected at a timing different from the frame synchronization timing detected at that time exceeds a threshold when a handover is anticipated. The V-polarization-side frame synchronization processing unit 1153 outputs this observation result as the handover candidate quality to the handover control unit 1180. This handover candidate quality indicates whether the correlation value exceeds the threshold. If it exceeds the threshold, it indicates sufficient quality.

[0323] If the handover candidate quality output from the synchronization processing unit 1151 indicates sufficient quality, the handover control unit 1180 outputs a handover execution signal to officially execute the handover. Upon receiving this handover execution signal, the synchronization processing unit 1151 immediately performs frame synchronization on the desired signal after the handover by treating the aforementioned different timing as the new frame synchronization timing. At this point, the synchronization processing unit 1151 generates a weight update instruction based on the newly generated frame synchronization timing and notifies the polarization signal processing unit 452.

[0324] As described above, in this embodiment, when handing over a signal with the same frequency but different polarizations, the frame synchronization timing is updated to the timing at which the correlation value of the SOF detected at a different timing exceeds the threshold. This allows for continuous, uninterrupted detection of the frame synchronization timing corresponding to the desired signal. Consequently, MMSE processing corresponding to the desired signal can be performed continuously even during handover, particularly improving the SINR near cell edges.

[0325] Here, the communication device 1100 in this embodiment includes a signal processing device for receiving a signal transmitted from the satellite 3000. The signal processing device includes, for example, a synchronization processing unit 1151, a polarization signal processing unit 452, and a handover control unit 1180. The handover control unit 1180 indicates a handover candidate signal having the same frequency and a different polarization wave than the transmission signal transmitted from the transmitting device such as the satellite 3000. When the handover candidate signal is indicated, the synchronization processing unit 1151 determines whether the handover candidate signal satisfies a prescribed condition based on the correlation value between the information included in the signals respectively received by the antenna for vertical polarization and the antenna for horizontal polarization and the known information. In addition, the known information is information for identifying the polarization wave of the signal, for example, a known bit pattern (18D2E82 HEX ). Furthermore, the predetermined condition may include, for example, a correlation value exceeding a threshold. Furthermore, the determination of whether the handover candidate quality is sufficient is performed by determining whether the handover candidate signal satisfies the predetermined condition. If the handover control unit 1180 determines that the handover candidate signal satisfies the predetermined condition, it outputs a handover execution signal. Upon receiving the handover execution signal, the synchronization processing unit 1151 and the polarization signal processing unit 452 switch the signal being processed from the aforementioned transmission signal to the handover candidate signal.

[0326] Figure 49 This is a flowchart showing an example of the processing actions of the signal processing device in embodiment 12.

[0327] First, the synchronization processing unit 1151 determines whether a handover candidate signal with different polarizations has been indicated (step S401a). If not indicated (step S401a: No), the synchronization processing unit 1151 performs coordinated synchronization processing on each of the vertical and horizontal signals, as described above (step S90). Furthermore, the polarization signal processing unit 452 performs polarization signal processing (step S100). On the other hand, if a handover candidate signal has been indicated (step S401a: Yes), the synchronization processing unit 1151 also performs coordinated synchronization processing on each of the vertical and horizontal signals (step S90). Then, the polarization signal processing unit 452 performs polarization signal processing (step S100). However, if a handover candidate signal has been indicated, the synchronization processing unit 1151 further determines the quality of the handover candidate signal based on the correlation value between the information contained in the signals received by the vertically polarized antenna and the horizontally polarized antenna, respectively, and known information (step S402). The handover control unit 1180 then determines whether the determined quality satisfies the handover criteria (step S403). If the quality satisfies the criteria (step S403: Yes), the handover control unit 1180 causes the synchronization processing unit 1151 and the polarization signal processing unit 452 to switch the signal being processed from the aforementioned transmission signal to the handover candidate signal (step S404).

[0328] Thus, the signal processing device and signal processing method of this embodiment can continuously perform synchronization timing detection for the desired signal even during handover. As a result, MMSE processing corresponding to the desired signal can be continuously performed even during handover, particularly improving the SINR near cell edges.

[0329] (Implementation 13)

[0330] Figure 50 This figure shows an example of the configuration of a communication device 1200 in Embodiment 13. Among the components of the communication device 1200 in this embodiment, components identical to those of the communication device in any one of Embodiments 1 to 12 are denoted by the same reference numerals as those of the components in that embodiment 1 to 12, and detailed descriptions thereof are omitted.

[0331] Figure 50The communication device 1200 includes a tuner unit 1210, a reference signal generator 155, A / D converters 1220V and 1220H, synchronization processors 1230V and 1230H, polarization signal processors 140V and 140H, FEC decoders 1250V and 1250H, and a handover controller 1280. As described above, in this disclosure, in the reference numerals assigned to various components, "V" indicates that the component is for V-polarization, and "H" indicates that the component is for H-polarization. Furthermore, in this disclosure, when "H" or "V" is omitted from a reference numeral, the reference numeral indicates that the component is for either or both V-polarization and H-polarization. For example, "A / D converter 1220" indicates either or both A / D converter 1220V and A / D converter 1220H.

[0332] In other words, in Figure 50 In the communication device 1200, Figure 25 Compared to the communication device 500 in the sixth embodiment shown, the tuner unit 110, A / D converter 120, synchronization processing unit 530, and FEC decoding unit 150 are replaced by a tuner unit 1210, A / D converter 1220, synchronization processing unit 1230, and FEC decoding unit 1250, respectively. Furthermore, the communication device 1200 includes two synchronization processing units 1230, two polarization signal processing units 140, and two FEC decoding units 1250, as well as a handover control unit 1280. Furthermore, the components of the communication device 1200 that include the components other than the tuner unit 1210, the reference signal generator 155, and the handover control unit 1280 may be implemented as an integrated circuit 1205. The tuner unit 1210 , A / D converter 1220 , synchronization processor 1230 , polarization signal processor 140 , FEC decoder 1250 , and handover controller 1280 in this embodiment can also be applied to Embodiments 1 to 12.

[0333] In this embodiment, the handover control unit 1280 specifies a signal having a frequency different from that of the current signal, or a signal having the same frequency but a different polarization than that of the current signal, as a handover candidate signal.

[0334] Figure 51 12 is a diagram showing an example of the minimum band that the tuner unit 1210 and the A / D converter 1220 pass. Figure 51 (a) shows the minimum band in Embodiments 1 to 12, and this minimum band is equal to the band of the desired signal being received. Figure 51 (b) shows the minimum band of this embodiment, and this minimum band includes all of the band of the desired signal being received and the band of the handover candidate signal.

[0335] According to the instruction from the handover control unit 1280, the tuner unit 1210 and the A / D converter unit 1220 operate so that at least Figure 51 The signal in the minimum band shown in (b) passes through.

[0336] Figure 52 This is a diagram showing an example of the configuration of the synchronization processing unit 1230 . Figure 52 The synchronization processing unit 1230 and Figure 26 Compared with the synchronization processing unit 530 in the sixth embodiment shown in the figure, the coarse frequency synchronization processing unit 131 and the frame synchronization processing unit 541 on the V polarization wave side and the H polarization wave side are replaced by the coarse frequency synchronization processing unit 1231 and the frame synchronization processing unit 1241, respectively. In addition, the coarse frequency synchronization processing unit 1231 obtains the handover information. That is, the handover control unit 1280 outputs information related to the band of the signal being received and the band of the handover candidate signal as the handover information. If the coarse frequency synchronization processing unit 1231 obtains the handover information, it processes so that the frequency of the tuned digital signal corresponds to the center frequency of the received signal to be processed (that is, one of the desired signal being received and the handover candidate signal). The frame synchronization processing unit 1241 outputs the detection result of the frame synchronization to the handover control unit 1280 as the reception quality. The reception quality is, for example, information indicating whether the correlation value of the SOF exceeds a threshold or the correlation value. Or, Figure 50 The FEC decoding unit 1250 shown may output the result of the error correction process to the handover control unit 1280 as reception quality (for example, error rate).

[0337] If the reception quality of the handover candidate signal exceeds the threshold, the handover control unit 1280 outputs a handover execution signal in the same manner as described above. Alternatively, if the reception quality of the handover candidate signal exceeds the reception quality of the desired signal being received, the handover control unit 1280 outputs a handover execution signal.

[0338] As described above, in this embodiment, when a handover occurs, information about the timing of the handover and the signal to be used after the handover is notified to the tuner unit 1210, A / D converter unit 1220, and synchronization processing unit 1230. Tuner unit 1210 and A / D converter unit 1220 then operate to pass signals in the minimum band that includes at least the band of the currently received desired signal and the band of the handover candidate signal. This allows continuous MMSE processing to mitigate the effects of interference components in both the desired signal and the handover candidate signal, improving the received SINR, even during a handover.

[0339] In addition, Figure 51If the minimum bandwidth shown in (b) is too wide and the tuner unit 1210 and the A / D converter unit 1220 cannot pass signals within the minimum bandwidth, at least only the desired signal being received may be passed. In this case, the handover control unit 1280 may determine whether to perform handover based on the reception quality of the desired signal after MMSE processing. For example, if the reception quality falls below a threshold, the handover control unit 1280 outputs a handover execution signal.

[0340] The communication device 1200 in this embodiment includes a signal processing device for receiving signals transmitted from the satellite 3000. This signal processing device includes, for example, a tuner unit 1210, a synchronization processing unit 1230, a polarization signal processing unit 140, and a handover control unit 1280. The tuner unit 1210 passes signals in a currently set frequency band from among the signals received by the vertically polarized antenna and the horizontally polarized antenna. The synchronization processing unit 1230 performs synchronization processing on the vertical and horizontal signals passing through the tuner unit 1210. The handover control unit 1280 indicates a handover candidate signal whose frequency and polarization differ from those of the transmitted signal. If a handover candidate signal is indicated, the tuner unit 1210 expands the frequency band to allow the handover candidate signal to pass. Furthermore, the synchronization processing unit 1230 determines whether the handover candidate signal meets predetermined conditions based on a correlation value between information contained in the handover candidate signal passing through the tuner unit 1210 and known information. Furthermore, the known information is information for identifying the polarization wave of the signal, such as a known bit pattern (18D2E82 HEX ). Furthermore, the predetermined condition may include, for example, a correlation value being greater than a threshold value. Furthermore, the determination of whether the reception quality of the aforementioned handover candidate signal is sufficient is performed by determining whether the handover candidate signal satisfies the predetermined condition. Next, the handover control unit 1280 outputs a handover execution signal if the handover candidate signal satisfies the predetermined condition. Upon receiving the handover execution signal, the synchronization processing unit 1230 and the polarization signal processing unit 140 switch the signal being processed from the aforementioned transmit signal to the handover candidate signal.

[0341] Figure 53 This is a flowchart showing an example of the processing actions of the signal processing device in embodiment 13.

[0342] First, the synchronization processing unit 1230 determines whether a handover candidate signal having at least one of a frequency and a polarization different from the transmitted signal has been indicated (step S401b). If not indicated (step S401b: No), the synchronization processing unit 1230 performs coordinated synchronization processing on each of the vertical and horizontal signals (step S90), as described above. Furthermore, the polarization signal processing unit 140 performs polarization signal processing (step S100). On the other hand, if a handover candidate signal has been indicated (step S401b: Yes), the tuner unit 1210 expands the frequency band to allow the handover candidate signal to pass (step S501). The synchronization processing unit 1230 then performs coordinated synchronization processing on each of the vertical and horizontal signals (step S90), and the polarization signal processing unit 140 performs polarization signal processing (step S100). When the handover candidate signal is instructed, the synchronization processing unit 1230 determines the quality of the handover candidate signal based on the correlation value between information included in the handover candidate signal that has passed through the tuner unit 1210 and known information (step S402).

[0343] The handover control unit 1280 then determines whether the determined quality satisfies the handover criteria (step S403). If the quality satisfies the criteria (step S403: Yes), the handover control unit 1280 causes the synchronization processing unit 1230 and the polarization signal processing unit 140 to switch the signal being processed from the aforementioned transmission signal to the handover candidate signal (step S404).

[0344] Thus, the signal processing apparatus and signal processing method of this embodiment can continuously reduce the influence of interference components in both the desired signal and the handover candidate signal during handover, regardless of the handover candidate signal type. Consequently, the received SINR can be improved.

[0345] (Implementation 14)

[0346] Figure 54 This figure shows an example of the configuration of a communication device 1300 in Embodiment 14. Among the components of communication device 1300 in this embodiment, components identical to those of the communication device in any one of Embodiments 1 to 13 are denoted by the same reference numerals as those in that embodiment, and detailed descriptions thereof are omitted.

[0347] Figure 54The communication device 1300 includes a tuner unit 1310, a reference signal generator 155, A / D converters 1320V and 1320H, a synchronization processor 1330, a polarization signal processor 140, an FEC decoder 1250, and a handover controller 1380. As described above, in this disclosure, in the reference numerals assigned to various components, "V" indicates that the component is for V-polarization, and "H" indicates that the component is for H-polarization. Furthermore, in this disclosure, when "H" or "V" is omitted from a reference numeral, the reference numeral indicates that the component is for either or both V-polarization and H-polarization. For example, "A / D converter 1320" indicates either or both A / D converter 1320V and A / D converter 1320H.

[0348] In other words, in Figure 54 In the communication device 1300, Figure 25 Compared to the communication device 500 in the sixth embodiment shown, the tuner unit 110, A / D converter 120, synchronization processing unit 530, and FEC decoding unit 150 are replaced with a tuner unit 1310, A / D converter 1320, synchronization processing unit 1330, and FEC decoding unit 1250, respectively. Furthermore, the communication device 1300 includes a handover control unit 1380. Furthermore, the components of the communication device 1300 other than the tuner unit 1310, reference signal generator 155, and handover control unit 1380 may be implemented as an integrated circuit 1305. Furthermore, the tuner unit 1310, A / D converter 1320, synchronization processing unit 1330, polarization signal processor 140, FEC decoding unit 1250, and handover control unit 1380 in this embodiment can also be applied to embodiments 1 to 13.

[0349] In this embodiment, similarly to Embodiment 13, the handover control unit 1380 specifies a signal having a frequency different from that of the current signal, or a signal having the same frequency but a different polarization than that of the current signal, as a handover candidate signal.

[0350] Figure 55 This diagram shows an example of the minimum band passed by the tuner unit 1310 and the A / D converter unit 1320 in this embodiment. The minimum band is equal to the band of the desired signal being received or the band of the handover candidate signal, and only one of the bands is selected in a time-sharing manner.

[0351] That is, according to the instruction from the handover control unit 1380, the tuner unit 1310 and the A / D converter unit 1320 are switched in a time-sharing manner. Figure 55 The minimum band shown is operated so as to pass the signal of the minimum band after switching.

[0352] Figure 56 This is a diagram showing an example of the configuration of the synchronization processing unit 1330 . Figure 56 The synchronization processing unit 1330 and Figure 26 Compared to the synchronization processing unit 530 in the sixth embodiment shown in the figure, the frame synchronization processing units 541 and 542 on the V polarization side and the H polarization side are replaced by frame synchronization processing units 1241 and 1242, respectively. The frame synchronization processing unit 1241 outputs the detection result of the frame synchronization corresponding to the received signal of the minimum band selected by time division (that is, one of the desired signal being received and the handover candidate signal) as the reception quality to the handover control unit 1380. The reception quality is, for example, information indicating whether the correlation value of the SOF exceeds a threshold or the correlation value. Or, Figure 54 The FEC decoding unit 1250 shown may output the result of the error correction process to the handover control unit 1380 as reception quality (for example, error rate).

[0353] If the reception quality of the handover candidate signal exceeds the threshold, handover control unit 1380 outputs a handover execution signal in the same manner as described above. Alternatively, if the reception quality of the handover candidate signal exceeds the reception quality of the desired signal being received, handover control unit 1280 outputs a handover execution signal.

[0354] As described above, in this embodiment, when a handover occurs, information about the timing of the handover and the signal to be used after the handover is notified to tuner unit 1310 and A / D converter unit 1320. Components subsequent to tuner unit 1310 then process the desired signal being received and the handover candidate signal in a time-sharing manner. This allows MMSE processing to be performed in a time-sharing manner even during a handover, mitigating the effects of interference components on the desired signal and the handover candidate signal, thereby improving the received SINR.

[0355] The communication device 1300 in this embodiment includes a signal processing device for receiving signals transmitted from the satellite 3000. This signal processing device includes, for example, a tuner unit 1310, a synchronization processing unit 1330, a polarization signal processing unit 140, and a handover control unit 1380. The tuner unit 1310 passes signals in the currently set first frequency band among the signals received by the vertically polarized antenna and the horizontally polarized antenna. The synchronization processing unit 1330 performs synchronization processing on the vertical and horizontal signals that have passed through the tuner unit 1310. The handover control unit 1380 indicates a handover candidate signal that differs from the transmitted signal in at least one of frequency and polarization. When the handover candidate signal is indicated, the tuner unit 1310 switches the frequency band for passing signals between the first frequency band and the second frequency band for passing the handover candidate signal in a time-division manner. The synchronization processing unit 1330 determines whether the handover candidate signal satisfies a predetermined condition based on a correlation value between information included in the handover candidate signal that has passed through the tuner unit 1310 and known information. The known information is information for identifying the polarization of the signal, such as a known bit pattern (18D2E82 HEX ). Furthermore, the predetermined condition may include, for example, a condition where the correlation value is greater than a threshold value. Furthermore, the determination of whether the reception quality of the handover candidate signal is sufficient is performed by determining whether the handover candidate signal satisfies the predetermined condition. Next, the handover control unit 1380 outputs a handover execution signal if the handover candidate signal satisfies the predetermined condition. Upon receiving the handover execution signal, the synchronization processing unit 1330 and the polarization signal processing unit 140 switch the signal being processed from the aforementioned transmission signal to the handover candidate signal.

[0356] Figure 57 This is a flowchart showing an example of the processing actions of the signal processing device in embodiment 14.

[0357] First, the synchronization processing unit 1330 determines whether a handover candidate signal having at least one of a frequency and a polarization different from the transmitted signal has been indicated (step S401b). If not indicated (step S401b: No), the synchronization processing unit 1330 performs coordinated synchronization processing on each of the vertical and horizontal signals as described above (step S90). Furthermore, the polarization signal processing unit 140 performs polarization signal processing (step S100). On the other hand, if a handover candidate signal has been indicated (step S401b: Yes), the tuner unit 1310 switches the frequency band for signal transmission to the first frequency band described above and the second frequency band for signal transmission in a time-division manner (step S502). The synchronization processing unit 1330 then performs coordinated synchronization processing on each of the vertical and horizontal signals (step S90), and the polarization signal processing unit 140 performs polarization signal processing (step S100). When the handover candidate signal is instructed, the synchronization processing unit 1330 determines the quality of the handover candidate signal based on the correlation value between information included in the handover candidate signal that has passed through the tuner unit 1310 and known information (step S402).

[0358] The handover control unit 1380 then determines whether the determined quality satisfies the handover criteria (step S403). If the quality satisfies the criteria (step S403: Yes), the handover control unit 1380 causes the synchronization processing unit 1330 and the polarization signal processing unit 140 to switch the signal being processed from the aforementioned transmission signal to the handover candidate signal (step S404).

[0359] Therefore, the signal processing device and signal processing method of this embodiment can reduce the influence of interference components in either the desired signal or the handover candidate signal in a time-division manner during handover, regardless of the handover candidate signal type. As a result, the received SINR can be improved.

[0360] (Implementation 15)

[0361] Figure 58 This figure shows an example of the configuration of communication device 1400 in Embodiment 15. Among the components of communication device 1400 in this embodiment, components identical to those of the communication device in any one of Embodiments 1 to 14 are denoted by the same reference numerals as those in that embodiment, and detailed descriptions thereof are omitted.

[0362] Figure 58 The communication device 1400 and Figure 50Compared to the communication device 1200 in the thirteenth embodiment shown, the polarization signal processing units 140V and 140H are replaced with polarization signal processing units 1440V and 1440H, and an antenna control unit 1490 is added. Furthermore, one or both of the polarization signal processing units 1440V and 1440H are also referred to as the polarization signal processing unit 1440. Furthermore, the unit including the components of the communication device 1400 other than the tuner unit 1210, the reference signal generation unit 155, the handover control unit 1280, and the antenna control unit 1490 may be configured as an integrated circuit 1405. Furthermore, the polarization signal processing unit 1440 and the antenna control unit 1490 in this embodiment can also be applied to embodiments 1 to 14.

[0363] Figure 59 1440 is a diagram showing an example of the configuration of the polarization signal processing unit 1440. Figure 7 Unlike the polarization signal processing unit 140 in the first embodiment, the polarization signal processing unit 140 outputs the MMSE weight to the antenna control unit 1490. Specifically, the weight calculation unit 170 calculates the MMSE weight and outputs the calculated weight to the weighting unit 175 and the antenna control unit 1490.

[0364] Figure 58 The antenna control unit 1490 shown in the figure changes the polarization plane to a certain direction while observing the MMSE weight output from the polarization signal processing unit 1440. For example, the antenna control unit 1490 begins changing the polarization plane to a predetermined direction after the change in the MMSE weight falls below a certain value. Here, the antenna control unit 1490 continues changing the polarization plane if the polarization rotation amount calculated based on the MMSE weight decreases. On the other hand, the antenna control unit 1490 changes the polarization plane to a direction different from the predetermined direction if the polarization rotation amount calculated based on the MMSE weight increases.

[0365] In this embodiment, by continuously performing such processing, the influence of interference components can be reduced in both the antenna control unit 1490 and the polarization signal processing unit 1440, thereby improving the received SINR.

[0366] The communication device 1400 in this embodiment includes a signal processing device for receiving signals transmitted from the satellite 3000. This signal processing device includes, for example, a tuner unit 1210, a synchronization processing unit 1230, a polarization signal processing unit 1440, a handover control unit 1280, and an antenna control unit 1490. The antenna control unit 1490 changes the polarization plane orientation of signals received by the vertically polarized wave antenna and the horizontally polarized wave antenna. Specifically, the antenna control unit 1490 changes the polarization plane orientation based on the first and second weights calculated by the weight calculation unit 170 of the polarization signal processing unit 1440.

[0367] Figure 60 This is a flowchart showing an example of the processing actions of the signal processing device in embodiment 15.

[0368] Should Figure 60 The flowchart shown contains Figure 53 The steps included in the flowchart further include step S601 . In step S601 , the antenna control unit 1490 changes the orientation of the polarization plane based on the first weight and the second weight calculated by the weight calculation unit 170 of the polarization signal processing unit 1440 .

[0369] Therefore, in the signal processing device and the signal processing method according to the present embodiment, the influence of the interference component can be further reduced, and the received SINR can be further improved.

[0370] (Replenish)

[0371] The present disclosure is not limited to the contents described in the above-mentioned Embodiments 1 to 15, and can be implemented in any form for achieving the purpose of the present disclosure and related or incidental purposes. For example, the following forms are also possible.

[0372] (1) In Embodiments 1 to 15, when it is impossible to distinguish which polarized wave receiving antenna is used to tune a satellite signal conforming to the DVB-S2X standard, the distinction may be made based on the positional relationship between the satellite and the aircraft.

[0373] (2) In Embodiments 1 to 15, the transmission power may be reduced by an amount corresponding to an expected improvement in the received SNR or SINR. For example, a method of reducing the power may be to control the amount of power amplification in the transmission RF processing.

[0374] (3) In Embodiments 1 to 15, the communication devices are not limited to those mounted on aircraft, but may also be mounted on mobile objects such as ships and cars that move over a large area on the earth.

[0375] (4) In Embodiments 1 to 15, the polarization plane of the antenna of the aircraft may be changed mechanically or electronically based on the calculated transmission path estimation value or MMSE weight.

[0376] (5) In Embodiments 1 to 15, the downlink satellite signal is configured to comply with the DVB-S2X standard. However, the present invention is not limited thereto and may also comply with the standard for non-terrestrial networks currently under discussion by 3GPP (The 3rd Generation Partnership Project).

[0377] (6) In the third embodiment, the uplink satellite signal is based on the DVB-RCS2 standard. However, the present invention is not limited thereto and may be based on a standard for non-terrestrial networks currently under discussion by 3GPP (The 3rd Generation Partnership Project).

[0378] (7) In Embodiments 1 to 15, orthogonal polarizations are V-polarization and H-polarization. However, this is not limiting; right-handed polarization and left-handed polarization may also be used. In this case, even in environments with reflected waves or where the received power between polarized waves differs, the plane of polarization must be considered. Embodiments 1 to 15 are effective.

[0379] (8) In Embodiments 1 to 15, communication between a satellite and a single aircraft is described as an example. However, the present invention is not limited thereto. In communication between a satellite and a plurality of aircraft, the communication devices of each aircraft can use Embodiments 1 to 15.

[0380] (9) In Embodiments 1 to 15, the weighting in the polarization signal processing unit may not be always on, but may be turned off depending on the situation. For example, the situation in which the weighting is turned off is when the absolute value of the transmission path estimation value is lower than a threshold.

[0381] (10) In Embodiments 1 to 15, the polarization signal processing unit is arranged after the synchronization processing unit. However, the present invention is not limited thereto and may be arranged after the precision frequency synchronization processing unit within the synchronization processing unit. In this case, the polarization signal processing unit may also include the function of the phase synchronization processing unit.

[0382] (11) In Embodiments 1 to 15, weighting processing is performed using MMSE, but the present invention is not limited thereto. For example, ZF (Zero Forcing) may be used.

[0383] (12) In Embodiments 1 to 15, the transmission path estimation value is calculated only within a single frame. However, the present invention is not limited to this. The value may be calculated across multiple frames, for example, using an IIR (Infinite Impulse Response) filter. In this case, although a time delay occurs, the accuracy of the transmission path estimation value is improved.

[0384] (13) Some of the first to fifteenth embodiments and their modifications may be combined with each other.

[0385] (14) In the communication apparatuses of the above-mentioned Embodiments 1 to 15, the unit corresponding to the downlink may be defined as a receiving apparatus, and the unit corresponding to the uplink may be defined as a transmitting apparatus.

[0386] (15) The above embodiments 1 to 15 may also involve installation using hardware and software. The above embodiments may also be installed or executed using a computing device (processor). The computing device or processor may be, for example, a main processor or a general purpose processor, a digital signal processor (DSP), an ASIC (application specific integrated circuit), an FPGA (field programmable gate array), or other programmable logic devices. The above embodiments may also be executed or implemented by a combination of these devices.

[0387] (16) Implementation methods 1 to 15 may also be implemented as a software module executed by a processor or directly by hardware. In addition, a combination of a software module and a hardware installation is also possible. The software module may also be stored in various computer-readable storage media, such as RAM (Random Access Memory), EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read-only Memory), flash memory, registers, hard disk, CD-ROM (compact disc read-only memory) or DVD, etc.

[0388] Industrial Applicability

[0389] The signal processing device disclosed herein can be applied to a communication device, a receiving device, and a transmitting device.

[0390] Description of reference numerals:

[0391] 100 communication devices

[0392] 110 Tuner Department

[0393] 130 Synchronous Processing Unit

[0394] 140 Polarization Signal Processing Unit

[0395] 140V polarization signal processing unit

[0396] 140H polarization signal processing unit

[0397] 150FEC decoding unit

[0398] 155 reference signal generating unit

[0399] 165H Transmission Path Estimation Unit

[0400] 165V transmission line estimation unit

[0401] 170 Weight Calculation Department

[0402] 175 weighted department

[0403] 2000 aircraft

[0404] 2010, 3010 antennas

[0405] 3000 satellites.

Claims

1. A signal processing device comprising: a first transmission path estimation unit for estimating a first transmission path characteristic of the transmission signal using a vertical signal, among vertical and horizontal signals obtained by receiving a transmission signal transmitted from a transmission device in one of a vertically polarized wave and a horizontally polarized wave via an antenna for vertically polarized waves and an antenna for horizontally polarized waves; a second transmission path estimating unit for estimating a second transmission path characteristic of the transmission signal using the horizontal signal; a weight calculation unit that calculates a first weight corresponding to the vertical signal and a second weight corresponding to the horizontal signal using the first transmission path characteristic and the second transmission path characteristic; a weighting unit configured to perform weighted addition on the vertical signal and the horizontal signal using the first weight and the second weight; a synchronization processing unit, performing synchronization processing on the vertical signal and the horizontal signal respectively; as well as The handover control unit instructs the handover candidate signal, The first transmission path characteristic is a characteristic of a transmission path for transmitting the transmission signal from the transmission device to the antenna for vertically polarized waves. The second transmission path characteristic is a characteristic of a transmission path for transmitting the transmission signal from the transmission device to the antenna for horizontally polarized waves. The first transmission path characteristic indicates a ratio of a signal contained in the vertical signal in the transmission signal. The second transmission path characteristic indicates the ratio of the signal contained in the horizontal signal in the transmission signal. When the handover candidate signal is indicated, the synchronization processing unit determines whether a received signal obtained by receiving the handover candidate signal through an antenna corresponding to a polarization wave different from the transmission signal among the vertically polarized wave antenna and the horizontally polarized wave antenna, or the handover candidate signal satisfies a predetermined condition. When the synchronization processing unit determines that the received signal or the handover candidate signal satisfies the predetermined condition, the handover control unit outputs a handover execution signal. The synchronization processing unit, the first transmission path estimation unit, the second transmission path estimation unit, the weight calculation unit, and the weighting unit, upon obtaining the handover execution signal, switch the signal to be processed from the transmission signal to the handover candidate signal. The first transmission path estimation unit estimates the first transmission path characteristic of the handover candidate signal using the vertical signal among the vertical signal and the horizontal signal obtained by receiving the handover candidate signal by the antenna for vertical polarization waves and the antenna for horizontal polarization waves. The second transmission path estimation unit estimates the second transmission path characteristic of the handover candidate signal using the horizontal signal among the vertical signal and the horizontal signal obtained by receiving the handover candidate signal by the antenna for vertical polarization waves and the antenna for horizontal polarization waves.

2. The signal processing device according to claim 1, The synchronization processing unit includes: a first synchronization processing unit that performs synchronization processing on the vertical signal; and The second synchronization processing unit performs synchronization processing on the horizontal signal. The first synchronization processing unit and the second synchronization processing unit further cooperate with each other to reduce the clock timing error between the vertical signal and the horizontal signal and to make the power sum of the vertical signal and the horizontal signal constant.

3. The signal processing device according to claim 1, further comprising: a polarization shifting unit that applies a polarization shift to the vertical signal and the horizontal signal; The synchronization processing unit performs synchronization processing on the vertical signal and the horizontal signal to which the polarization shift is applied, respectively. The polarization shifting unit applies polarization shift to the vertical signal and the horizontal signal to be subsequently subjected to synchronization processing based on at least one of (i) the result of synchronization processing by the synchronization processing unit and (ii) information included in the signal obtained by the weighted addition.

4. The signal processing device according to claim 1, The handover control unit indicates a handover candidate signal having a frequency different from that of the transmission signal. In case the handover candidate signal is indicated, (i) the weighting unit does not perform the weighted addition, and (ii) the synchronization processing unit determines whether the received signal satisfies the predetermined condition, The handover control unit outputs the handover execution signal when the synchronization processing unit determines that the received signal satisfies the predetermined condition.

5. The signal processing device according to claim 1, The handover control unit indicates a handover candidate signal having the same frequency and a different polarization from the transmission signal. When the handover candidate signal is indicated, the synchronization processing unit determines whether the handover candidate signal satisfies the predetermined condition based on a correlation value indicating a correlation between information included in the signals received by the vertically polarized wave antenna and the horizontally polarized wave antenna, respectively, and known information. The handover control unit outputs the handover execution signal when the synchronization processing unit determines that the handover candidate signal satisfies the predetermined condition.

6. The signal processing device according to claim 1, further comprising: The tuner section passes a signal of a currently set frequency band among the signals received by the vertically polarized wave antenna and the horizontally polarized wave antenna. The handover control unit indicates a handover candidate signal having at least one of a frequency and a polarization different from the transmission signal. The synchronization processing unit performs synchronization processing on the vertical signal and the horizontal signal that have passed through the tuner unit, respectively. In case the handover candidate signal is indicated, (i) the tuner unit expands the frequency band to allow the handover candidate signal to pass through, and (ii) the synchronization processing unit determines whether the handover candidate signal satisfies the predetermined condition based on a correlation value indicating a correlation between information included in the handover candidate signal that has passed through the tuner unit and known information; The handover control unit outputs the handover execution signal when the synchronization processing unit determines that the handover candidate signal satisfies the predetermined condition.

7. The signal processing device according to claim 1, further comprising: The tuner section passes a signal of a currently set first frequency band among the signals received by the vertically polarized wave antenna and the horizontally polarized wave antenna. The handover control unit indicates a handover candidate signal having at least one of a frequency and a polarization different from the transmission signal. The synchronization processing unit performs synchronization processing on the vertical signal and the horizontal signal that have passed through the tuner unit, respectively. In case the handover candidate signal is indicated, (i) the tuner unit switches the frequency band for passing the signal to the first frequency band and the second frequency band for passing the handover candidate signal in a time-division manner, and (ii) the synchronization processing unit determines whether the handover candidate signal satisfies the predetermined condition based on a correlation value indicating a correlation between information included in the handover candidate signal that has passed through the tuner unit and known information; The handover control unit outputs the handover execution signal when the synchronization processing unit determines that the handover candidate signal satisfies the predetermined condition.

8. The signal processing device according to claim 1, further comprising: The antenna control unit changes the direction of the polarization plane of the signal received by the vertically polarized wave antenna and the horizontally polarized wave antenna. The antenna control unit changes the orientation of the plane of polarization based on the first weight and the second weight calculated by the weight calculation unit.

9. A signal processing method, comprising: estimating a first transmission path characteristic of the transmission signal using the vertical signal, among vertical and horizontal signals obtained by receiving a transmission signal transmitted from a transmission device using one of a vertically polarized wave and a horizontally polarized wave using an antenna for vertically polarized waves and an antenna for horizontally polarized waves; estimating a second transmission path characteristic of the transmission signal using the horizontal signal, using the first transmission path characteristic and the second transmission path characteristic, calculating a first weight corresponding to the vertical signal and a second weight corresponding to the horizontal signal; performing weighted addition on the vertical signal and the horizontal signal using the first weight and the second weight, Performing synchronous processing on the vertical signal and the horizontal signal respectively, Indicates the handover candidate signal, determining, in accordance with an indication of the handover candidate signal, whether a received signal obtained by receiving an antenna corresponding to a polarization different from that of the transmitted signal, or the handover candidate signal, among the vertically polarized wave antenna and the horizontally polarized wave antenna, satisfies a predetermined condition; If it is determined that the received signal or the handover candidate signal satisfies the predetermined condition, a handover execution signal is output; In the synchronization processing, estimating the first transmission path characteristic, estimating the second transmission path characteristic, calculating the first weight, calculating the second weight, and performing the weighted addition, the signal to be processed is switched from the transmission signal to the handover candidate signal in accordance with the output of the handover execution signal, and the first transmission path characteristic of the handover candidate signal is estimated using the vertical signal among the vertical signal and the horizontal signal obtained by receiving the handover candidate signal by the vertically polarized wave antenna and the horizontally polarized wave antenna, and the second transmission path characteristic of the handover candidate signal is estimated using the horizontal signal among the vertical signal and the horizontal signal obtained by receiving the handover candidate signal by the vertically polarized wave antenna and the horizontally polarized wave antenna. The first transmission path characteristic is a characteristic of a transmission path for transmitting the transmission signal from the transmission device to the antenna for vertically polarized waves. The second transmission path characteristic is a characteristic of a transmission path for transmitting the transmission signal from the transmission device to the antenna for horizontally polarized waves. The first transmission path characteristic indicates a ratio of a signal contained in the vertical signal in the transmission signal. The second transmission path characteristic indicates a ratio of a signal included in the horizontal signal in the transmission signal.

10. A computer-readable non-volatile recording medium having a program recorded thereon, the program causing a computer to execute: estimating a first transmission path characteristic of the transmission signal using the vertical signal, among vertical and horizontal signals obtained by receiving a transmission signal transmitted from a transmission device using one of a vertically polarized wave and a horizontally polarized wave using an antenna for vertically polarized waves and an antenna for horizontally polarized waves; estimating a second transmission path characteristic of the transmission signal using the horizontal signal, using the first transmission path characteristic and the second transmission path characteristic, calculating a first weight corresponding to the vertical signal and a second weight corresponding to the horizontal signal; performing weighted addition on the vertical signal and the horizontal signal using the first weight and the second weight, Performing synchronous processing on the vertical signal and the horizontal signal respectively, Indicates the handover candidate signal, determining, in accordance with an indication of the handover candidate signal, whether a received signal obtained by receiving an antenna corresponding to a polarization different from that of the transmitted signal, or the handover candidate signal, among the vertically polarized wave antenna and the horizontally polarized wave antenna, satisfies a predetermined condition; If it is determined that the received signal or the handover candidate signal satisfies the predetermined condition, a handover execution signal is output; In the synchronization processing, estimating the first transmission path characteristic, estimating the second transmission path characteristic, calculating the first weight, calculating the second weight, and performing the weighted addition, the signal to be processed is switched from the transmission signal to the handover candidate signal in accordance with the output of the handover execution signal, and the first transmission path characteristic of the handover candidate signal is estimated using the vertical signal among the vertical signal and the horizontal signal obtained by receiving the handover candidate signal by the vertically polarized wave antenna and the horizontally polarized wave antenna, and the second transmission path characteristic of the handover candidate signal is estimated using the horizontal signal among the vertical signal and the horizontal signal obtained by receiving the handover candidate signal by the vertically polarized wave antenna and the horizontally polarized wave antenna. The first transmission path characteristic is a characteristic of a transmission path for transmitting the transmission signal from the transmission device to the antenna for vertically polarized waves. The second transmission path characteristic is a characteristic of a transmission path for transmitting the transmission signal from the transmission device to the antenna for horizontally polarized waves. The first transmission path characteristic indicates a ratio of a signal contained in the vertical signal in the transmission signal. The second transmission path characteristic indicates a ratio of a signal included in the horizontal signal in the transmission signal.

11. A mobile object comprising: signal processing device; Antennas for vertically polarized waves; and Antenna for horizontally polarized waves, The signal processing device comprises: a first transmission path estimation unit for estimating a first transmission path characteristic of the transmission signal using a vertical signal, among vertical and horizontal signals obtained by receiving a transmission signal transmitted from a transmission device in one of a vertically polarized wave and a horizontally polarized wave via an antenna for vertically polarized waves and an antenna for horizontally polarized waves; a second transmission path estimating unit for estimating a second transmission path characteristic of the transmission signal using the horizontal signal; a weight calculation unit that calculates a first weight corresponding to the vertical signal and a second weight corresponding to the horizontal signal using the first transmission path characteristic and the second transmission path characteristic; a weighting unit configured to perform weighted addition on the vertical signal and the horizontal signal using the first weight and the second weight; a synchronization processing unit, performing synchronization processing on the vertical signal and the horizontal signal respectively; as well as The handover control unit instructs the handover candidate signal, The first transmission path characteristic is a characteristic of a transmission path for transmitting the transmission signal from the transmission device to the antenna for vertically polarized waves. The second transmission path characteristic is a characteristic of a transmission path for transmitting the transmission signal from the transmission device to the antenna for horizontally polarized waves. The first transmission path characteristic indicates a ratio of a signal contained in the vertical signal in the transmission signal. The second transmission path characteristic indicates the ratio of the signal contained in the horizontal signal in the transmission signal. When the handover candidate signal is indicated, the synchronization processing unit determines whether a received signal obtained by receiving the handover candidate signal through an antenna corresponding to a polarization wave different from the transmission signal among the vertically polarized wave antenna and the horizontally polarized wave antenna, or the handover candidate signal satisfies a predetermined condition. When the synchronization processing unit determines that the received signal or the handover candidate signal satisfies the predetermined condition, the handover control unit outputs a handover execution signal. The synchronization processing unit, the first transmission path estimation unit, the second transmission path estimation unit, the weight calculation unit, and the weighting unit, upon obtaining the handover execution signal, switch the signal to be processed from the transmission signal to the handover candidate signal. The first transmission path estimation unit estimates the first transmission path characteristic of the handover candidate signal using the vertical signal among the vertical signal and the horizontal signal obtained by receiving the handover candidate signal by the antenna for vertical polarization waves and the antenna for horizontal polarization waves. The second transmission path estimation unit estimates the second transmission path characteristic of the handover candidate signal using the horizontal signal among the vertical signal and the horizontal signal obtained by receiving the handover candidate signal by the antenna for vertical polarization waves and the antenna for horizontal polarization waves.

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