JP2017005680A - Measuring instrument, chip and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the DU ratio of broadcast wave, without stopping the signals of broadcast waves transmitted from a transmitting station.SOLUTION: Broadcast waves containing orthogonal SP signals are transmitted, respectively, from the transmitter 101 of A station and the transmitter 102 of B station. A measuring instrument 1 receives broadcast waves superposing the SP signals from the transmitter 101 and the SP signals from the transmitter 102. An SP extraction unit 13 extracts the SP signals from the carrier symbol of an OFDM signal received via a receiving antenna 3. A SP interpolation unit 14 obtains transmission path responses a, b by interpolating the SP signal thus extracted, by using the orthogonality of the SP signal. A DU ratio calculation unit 15 obtains powers Pa, Pb by integrating the transmission path responses a, b in the carrier direction, and calculates the DU ratio based on the powers Pa, Pb. Consequently, the transmission path responses a, b are obtained by using the orthogonal SP signals separable from each other, and the DU ratio of broadcast waves between A, B stations can be measured.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a measuring instrument, chip and program for measuring a DU ratio (Desired to Undesired signal ratio).

  ISDB-T (Integrated Services Digital Broadcasting-Terrestrial), a Japanese terrestrial digital broadcasting system, realizes high-definition (registered trademark) broadcasting (or multiple standard-definition broadcasting) for fixed reception. In the next-generation terrestrial digital broadcasting system, instead of the conventional Hi-Vision (registered trademark), 3D Hi-Vision broadcasting or Super Hi-Vision with 16 times the resolution of Hi-Vision (registered trademark) will provide services with more information. Is required. Therefore, reducing the required C / N by increasing the data capacity and error correction technology has been an issue.

  In recent years, as a method for expanding the data transmission capacity by radio, for example, 2 × 2 polarization MIMO (Multiple Input Multiple Output: Multiple Input Multiple Output: Multiple Input Multiple Output: Multiple Input) Multi-output) has been proposed. In addition, STC-SFN that combines STC (Space Time Code) and SFN (Single Frequency Network) technology has been proposed (for example, see Non-Patent Documents 1 and 2).

  In STC-SFN, it is assumed that an SFN is constructed between two transmitting stations A and B. A 4 × 2 polarization MIMO system is configured by the A and B stations on the transmission side and the reception side. Each of the A and B stations on the transmission side transmits H polarization and V polarization from the two transmission antennas, and on the reception side, the H polarization and V polarization transmitted from the A station by the two reception antennas. In addition to receiving the wave, it receives and demodulates the H polarization and V polarization transmitted from station B.

  In the transmission path from the transmission side to the reception side, SP (Scattered Pilot: scattered pilot) orthogonal to each of the four components of H polarization and V polarization from the A station and H polarization and V polarization from the B station. ) The signal is superimposed, and the receiving side obtains the transmission line response by extracting each SP signal from the superimposed signal.

Tsuji, "Transmission technology for next-generation terrestrial broadcasting-STC-Examination of pilot system for SDM transmission-", Eiji techno vol.36, No.42, p33 (2012) Tsuji, "Transmission technology for next-generation terrestrial broadcasting-STC-Examination of SFN applying SDM transmission-", Eizo-Jigaku Technical Report Vol.36, No.51, p21 (2012)

  When measuring the DU ratio between the A station and the B station in such a polarization MIMO system, the transmission of the broadcast wave from the A station is stopped while the broadcast wave is transmitted from both stations ( The reception level of the broadcast wave from station B is measured by stopping the signal of station A). Then, in a state where broadcast waves are transmitted from both stations, transmission of the broadcast wave from station B is stopped (the signal of station B is stopped), and the reception level of the broadcast wave from station A is measured. Measure the DU ratio. This is because in terrestrial digital broadcasting, the broadcast waves transmitted from the A and B stations are essentially the same signal, and when the broadcast waves are transmitted from both stations, the two broadcast waves can be distinguished. It is not possible.

  Thus, in order to measure the DU ratio between the A and B stations, there is a problem that it is necessary to stop the signals of the A and B stations. Further, when measuring the DU ratio using the delay profile, it is impossible to determine whether the multipath wave is a broadcast wave from the A or B station, and an accurate DU ratio cannot be measured. There was a problem. This is not only a polarization MIMO system that uses both polarizations, but also a spatial MIMO system that does not use polarization, a directional MIMO system, a MISO (Multiple Input Single Output) system that uses the same polarization, The same applies to a spatial MISO system that does not use polarization.

  Accordingly, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a measuring instrument capable of measuring the DU ratio of a broadcast wave without stopping the broadcast wave signal transmitted from the transmitting station. It is to provide a chip and a program.

  In order to solve the above-mentioned problem, the measuring device according to claim 1 receives broadcast waves transmitted from a plurality of transmission stations, and receives a DU ratio (waves from a desired station and waves from other than the desired station) between the broadcast stations. In the measuring device for measuring the ratio between the broadcast wave including the pilot signal orthogonal to each of the plurality of transmitting stations, the pilot signal is obtained from the carrier symbol of the broadcast wave on which the orthogonal pilot signal is superimposed. An SP extracting unit for extracting, an SP interpolating unit for interpolating the pilot signal extracted by the SP extracting unit to obtain a transmission path response for each path from the plurality of transmitting stations to the measuring device, and the SP interpolating unit; A DU ratio calculation unit that integrates the obtained transmission path response for each path in a carrier direction, calculates power for each path, and calculates the DU ratio based on the power for each path; You .

  The measuring device according to claim 2 is the measuring device according to claim 1, wherein when the broadcast wave is received from the plurality of transmitting stations through a path of a MISO (multiple input single output) system, the SP is used. An interpolation unit obtains transmission path responses of a plurality of paths in the MISO system, the DU ratio calculation unit integrates transmission path responses of the plurality of paths obtained by the SP interpolation unit in a carrier direction, and the plurality of paths Of the plurality of paths, and the power in the path to the predetermined one transmitting station and the power in the path to the transmitting station other than the predetermined one transmitting station. A ratio is calculated as the DU ratio.

  The measuring device according to claim 3 is the measuring device according to claim 1, wherein the SP interpolation is performed when broadcast waves are received from the plurality of transmitting stations via a path of a MIMO (multiple input multiple output) system. A transmission path response of a plurality of paths in the MIMO system, the DU ratio calculation section integrates the transmission path responses of the plurality of paths obtained by the SP interpolation section in a carrier direction, and The power of each of the plurality of paths is calculated, and the ratio of the power in the path to the predetermined one transmitting station and the power in the path to the transmitting station other than the predetermined one transmitting station among the powers of the plurality of paths Is calculated as the DU ratio.

  Further, the measuring device according to claim 4 is the measuring device according to claim 3, wherein different polarizations are received from the plurality of transmitting stations via a path of a MIMO (multiple input multiple output) system. A new DU ratio calculation unit in place of the DU ratio calculation unit integrates transmission path responses in a plurality of paths to a receiving antenna that receives a predetermined type of polarization in the carrier direction, and obtains powers of the plurality of paths, respectively. Of the powers of the plurality of paths, the ratio of the power in the path to the predetermined one transmitting station and the power in the path to the transmitting station other than the predetermined one transmitting station is the predetermined type. It is calculated as a DU ratio of the polarized wave.

  Furthermore, the chip of claim 5 is a chip mounted on a device that receives broadcast waves transmitted from a plurality of transmission stations, and broadcast waves including orthogonal pilot signals are transmitted from the plurality of transmission stations, respectively. An SP extraction unit that extracts a pilot signal from carrier symbols of broadcast waves on which orthogonal pilot signals are superimposed, and the pilot signal extracted by the SP extraction unit are interpolated, and each path from the plurality of transmitting stations to the device is interpolated. An SP interpolator that obtains the transmission path response, and integrates the transmission path response for each path obtained by the SP interpolator in the carrier direction to obtain the power for each path, and based on the power for each path, the broadcast And a DU ratio calculation unit that calculates a DU ratio of a wave (a ratio between a wave from a desired station and a wave from other than the desired station).

  The program according to claim 6 is a program for an apparatus for receiving a broadcast wave including pilot signals orthogonal to each other from a plurality of transmitting stations, wherein a pilot signal is obtained from a carrier symbol of a broadcast wave on which the orthogonal pilot signals are superimposed. Extracting, interpolating the pilot signal, obtaining a transmission path response for each path from the plurality of transmitting stations to the apparatus, integrating the transmission path response for each path in a carrier direction, and for each path And calculating a DU ratio of the broadcast wave (a ratio between a wave from a desired station and a wave from other than the desired station) based on the power for each path. It is made to perform.

  As described above, according to the present invention, it is possible to measure the DU ratio between transmission stations without stopping the broadcast wave signal transmitted from the transmission station.

1 is a schematic diagram illustrating an example of the overall configuration of a MISO system according to a first embodiment. It is a figure explaining the example of SP pattern used in Example 1. FIG. It is a figure explaining the transmission line response of each path | route in Example 1. FIG. 2 is a block diagram illustrating a configuration example of a measuring instrument according to Embodiment 1. FIG. It is a flowchart which shows the process example of a DU ratio calculation part. FIG. 3 is a schematic diagram illustrating an example of the overall configuration of a MIMO system according to a second embodiment. It is a figure explaining the example of SP pattern used in Example 2. FIG. It is a figure explaining the transmission line response of each path | route in Example 2. FIG. It is a block diagram which shows the structural example of the measuring device of Example 2. FIG. It is a figure which shows the example of the transmission line response between the A stations in Example 2. FIG.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is characterized in that in a MISO system or a MIMO system, a DU ratio of a broadcast wave between transmitting stations is measured using orthogonal SP signals. The measuring device of the present invention obtains the transmission path response of each path from the signal on which the orthogonal SP signals are superimposed, obtains the power from the transmission path response, and measures the DU ratio of the broadcast wave between the transmitting stations. Here, when the orthogonal SP signals are superimposed, the SP signals of each path can be extracted by performing four arithmetic operations on the superimposed signals, and the transmission path response of each path can be obtained.

  Hereinafter, an example of the MISO system will be described in the first embodiment, and an example of a polarization MIMO system will be described in the second embodiment.

[Example 1]
First, Example 1 will be described. Example 1 is an STC-SFN 2 × 1 MISO system including two transmitting stations (A and B stations) each having one transmitting antenna and a measuring device having one receiving antenna. In this example, the DU ratio between the A and B stations is measured using two orthogonal SP signals. Broadcast waves transmitted from the A and B stations are MISO modulated. The DU ratio is an important parameter in designing the broadcast area for constructing the SFN, and is a measurement item mounted on the measuring instrument. The first embodiment is an example in which the same polarization is used, but the present invention is also applicable to a MISO system that uses different polarizations, a spatial MISO system that does not use polarization, and the like.

[MISO System / Example 1]
FIG. 1 is a schematic diagram illustrating an example of the overall configuration of the MISO system according to the first embodiment. This MISO system is an STC-SFN system, and includes a transmission device 101 provided in the A station, a transmission device 102 provided in the B station, and the measuring device 1. The transmission apparatus 101 includes one transmission antenna 111, the transmission apparatus 102 includes one transmission antenna 112, and the measuring instrument 1 includes one reception antenna 3. The two transmission antennas 111 and 112 and the one reception antenna 3 constitute a 2 × 1 MISO system as a whole.

  The transmission apparatus 101 and the transmission apparatus 102 generate OFDM signals including SP signals that are orthogonal to each other, and transmit broadcast waves from the transmission antennas 111 and 112, respectively. In the transmission path from the transmission device 101 and the transmission device 102 to the measuring instrument 1, the respective SP signals are superimposed.

  FIG. 2 is a diagram for explaining an example of the SP pattern used in the first embodiment. 2 (1) and (3) are examples of SP patterns used for the transmitting apparatus 101 of the A station, and FIGS. 2 (2) and (4) are examples of SP patterns used for the transmitting apparatus 102 of the B station. When the SP pattern of FIG. 2 (1) is used in the transmitting apparatus 101 of the A station, the SP pattern of FIG. 2 (2) is used in the transmitting apparatus 102 of the B station. When the SP pattern of FIG. 2 (3) is used in the transmitting apparatus 101 of the A station, the SP pattern of FIG. 2 (4) is used in the transmitting apparatus 102 of the B station. The horizontal axis indicates the carrier direction, and the vertical axis indicates the symbol direction. Black circles and black squares indicate positive SP signals (1 + 0j), white circles and white squares indicate null SP signals (0 + 0j), and squares with crosses indicate negative SP signals (−1 + 0j).

  As shown in FIGS. 2 (1) and 2 (2), SP signals are arranged in each symbol, and in the same symbol, 12 signals are arranged in the carrier direction, and a positive SP signal and a null SP signal are They are alternately arranged at intervals of 24. In addition, the SP signals are arranged every 3 carriers in a plurality of symbols, and are arranged at intervals of 4 symbols in the symbol direction in the same carrier. The positive SP signal and the null SP signal are alternately arranged at intervals of 8 symbols. Has been placed.

  As described above, the SP signal has a pattern with a period of 8 symbols, and the SP signals in FIGS. 2 (1) and 2 (2) are orthogonal. By using such orthogonal SP signals, the transmission path response from the transmitting apparatus 101 of the A station to the measuring instrument 1 and the transmission path response from the B station 102 to the measuring instrument 1 can be obtained individually. it can.

  FIGS. 2 (1) and 2 (2) show examples of SP patterns in which positive pilots and null pilots are combined. However, as shown in FIGS. 2 (3) and (4), SP patterns only for positive pilots. , And an SP pattern in which a positive pilot and a negative pilot (inverted pilot) are combined may be used. Further, as shown in FIG. 7 to be described later, the SP patterns of FIGS. 7 (1) and (3) may be used, or the SP patterns of FIGS. 7 (2) and (4) may be used. 7 (1) and (4) may be used, or the SP patterns of FIGS. 7 (2) and (3) may be used. Further, assuming that the interval after SP signal interpolation in the carrier direction is Dx and the symbol direction interval is Dy, FIG. 2 shows (Dx, Dy) = (3, 4) as an example of these combinations. On the other hand, various combinations such as (Dx, Dy) = (6, 2), (6, 4) may be used. In any case, the SP signals are orthogonal, and any orthogonal pattern may be used as long as each component can be separated individually.

  FIG. 3 is a diagram illustrating the transmission path response of each path in the first embodiment. In the MISO system shown in FIG. 1, two paths are formed between the transmitting apparatus 101 of the A station and the transmitting apparatus 102 of the B station and the measuring instrument 1. The transmission path response of the path from the transmission antenna 111 of the transmission apparatus 101 to the reception antenna 3 of the measuring instrument 1 is a, and the transmission path response of the path from the transmission antenna 112 of the transmission apparatus 102 to the reception antenna 3 of the measurement apparatus 1 is b. And

  The broadcast wave transmitted from the transmission antenna 111 of the transmission apparatus 101 is transmitted to the reception antenna 3 of the measuring instrument 1 via the path of the transmission path response a, and the broadcast wave transmitted from the transmission antenna 112 of the transmission apparatus 102 is It is transmitted to the receiving antenna 3 of the measuring instrument 1 via the path of the transmission path response b. At this time, the SP signal from the transmission apparatus 101 and the SP signal from the transmission apparatus 102 are superimposed on the transmission path from the transmission apparatus 101 and the transmission apparatus 102 to the measuring instrument 1.

  Returning to FIG. 1, the measuring device 1 receives the broadcast wave from the transmission device 101 and the broadcast wave from the transmission device 102 by the reception antenna 3, and uses the orthogonality of the SP signal to superimpose the signal. The respective SP signals are extracted to obtain transmission line responses a and b.

  The measuring device 1 calculates power based on the transmission path response a, calculates power based on the transmission path response b, and calculates a DU ratio from both powers. As a result, the DU ratio with the reception antenna 3 of the measuring instrument 1 as the reception point is calculated.

[Measuring instrument 1 / Example 1]
Next, the measuring instrument 1 shown in FIG. 1 will be described in detail. FIG. 4 is a block diagram illustrating a configuration example of the measuring instrument 1 according to the first embodiment. The measuring instrument 1 includes a receiving antenna 3, an effective symbol period extraction unit 11, an FFT (Fast Fourier Transform) unit 12, an SP extraction unit 13, an SP interpolation unit 14, and a DU ratio calculation unit 15.

  FIG. 4 shows only the components that are directly related to the present invention, and the components that are not directly related to the present invention, such as a symbol synchronization unit, are omitted. The processing of the constituent units from the effective symbol period extracting unit 11 to the SP interpolation unit 14 is the same as the conventional processing unit for processing OFDM signals.

  When measuring device 1 receives broadcast waves transmitted from transmission apparatuses 101 and 102 at receiving antenna 3, effective symbol period extraction unit 11 receives the OFDM signal of the received broadcast wave, and uses the effective symbol from the OFDM signal. The period is extracted, and the signal of the effective symbol period is output to the FFT unit 12. Specifically, the effective symbol period extraction unit 11 receives symbol timing from a symbol synchronization unit (not shown), extracts a GI period and an effective symbol period from the received OFDM signal based on the symbol timing, and removes the GI period. Thus, the effective symbol period is extracted.

  The FFT unit 12 receives the signal of the effective symbol period from the effective symbol period extraction unit 11, performs fast Fourier transform on the signal of the effective symbol period, converts the time domain signal into the frequency domain signal, and converts the carrier symbol to Generate. The FFT unit 12 outputs the carrier symbol to the SP extraction unit 13.

  The SP extraction unit 13 receives a carrier symbol from the FFT unit 12, extracts an SP signal at a predetermined position from the carrier symbol, and outputs the SP signal (reception SP signal) to the SP interpolation unit 14.

  The SP interpolation unit 14 receives the SP signal from the SP extraction unit 13 and interpolates the SP signal in the carrier direction (frequency direction) and / or the symbol direction (time direction). Then, the SP interpolation unit 14 obtains transmission path responses a and b based on the SP signal after interpolation, and outputs the transmission path responses a and b to the DU ratio calculation unit 15.

  Here, the SP signal (received SP signal) input from the SP extraction unit 13 is an SP signal from the transmission apparatus 101 shown in FIG. 2A and an SP signal from the transmission apparatus 102 shown in FIG. These SP signals are orthogonal to each other. For this reason, the SP interpolation unit 14 can extract the SP signal from the transmission apparatus 101 from the received SP signal to obtain the transmission path response a, and extract the SP signal from the transmission apparatus 102 to obtain the transmission path response b. Can be requested.

  The DU ratio calculation unit 15 receives the transmission path responses a and b from the SP interpolation section 14, integrates the transmission path responses a and b in the carrier direction, obtains power, calculates the DU ratio based on the power, The ratio is output to a display unit or the like.

  FIG. 5 is a flowchart illustrating a processing example of the DU ratio calculation unit 15. First, the DU ratio calculation unit 15 inputs the transmission path responses a and b of each path from the SP interpolation unit 14 (step S501). The transmission path response a is a transmission path response of all the carriers after interpolation (the carrier on which the SP signal is arranged) on the path from the transmission antenna 111 of the transmission apparatus 101 to the reception antenna 3 of the measuring instrument 1. The transmission path response b is a transmission path response of all the carriers after interpolation (the carrier on which the SP signal is arranged) on the path from the transmission antenna 112 of the transmission apparatus 102 to the reception antenna 3 of the measuring instrument 1.

  The DU ratio calculation unit 15 integrates the transmission path response a of all carriers after interpolation in the carrier direction, calculates the power Pa of the broadcast wave from the transmission apparatus 101, and calculates the transmission path response b of all carriers after interpolation. Integration in the carrier direction is performed to calculate the power Pb of the broadcast wave from the transmission apparatus 102 (step S502).

The DU ratio calculation unit 15 calculates the DU ratio of the broadcast wave between the stations A and B by dividing the power Pa by the power Pb using the following equation (step S503). Then, the DU ratio calculation unit 15 outputs the DU ratio to a display unit or the like (step S504).
[Equation 1]
DU ratio = Pa / Pb (1)
This DU ratio is a ratio when the broadcast wave from the transmission apparatus 101 is a desired wave and the broadcast wave from the transmission apparatus 102 is a wave from other than the desired station. The DU ratio is generally a ratio between a desired wave and an interfering wave, but here, it means a ratio between a wave from a desired station (desired wave) and a wave from other than the desired station. And The same applies to the second embodiment.

  Note that the DU ratio calculation unit 15 replaces the denominator and numerator of the above formula (1) so that the broadcast wave from the transmission device 102 is a desired wave and the broadcast wave from the transmission device 101 is a wave from other than the desired station. The DU ratio may be calculated.

  As described above, according to the measuring instrument 1 of the first embodiment, broadcast waves including SP signals orthogonal to each other are transmitted from the transmitting device 101 of the A station and the transmitting device 102 of the B station, and the broadcast wave on which the SP signal is superimposed. Receive. The SP extraction unit 13 extracts the SP signal from the carrier symbol of the received OFDM signal, and the SP interpolation unit 14 interpolates the SP signal by using the orthogonality of the SP signal to obtain the transmission path responses a and b. Ask. Then, the DU ratio calculation unit 15 calculates power by calculating the DU ratio by integrating the transmission path responses a and b in the carrier direction.

  Thus, by using orthogonal SP signals that are separable from each other, the DU ratio between the A and B stations can be measured without stopping the signals of the A and B stations.

[Example 2]
Next, Example 2 will be described. Example 2 is an STC-SFN 4 × 2 polarization MIMO composed of two transmitting stations (A and B stations) each having two transmitting antennas and a measuring device having two receiving antennas. This is an example in which the DU ratio between the A and B stations is measured using four orthogonal SP signals in the system. Broadcast waves transmitted from the A and B stations are polarized MIMO waves. The DU ratio is an important parameter in designing the broadcast area for constructing the SFN, and is a measurement item mounted on the measuring instrument. The second embodiment is an example using both polarized waves, but the present invention is also applicable to a spatial MIMO system, a directional MIMO system, etc. that do not use polarized waves.

[MIMO system / Example 2]
FIG. 6 is a schematic diagram illustrating an example of the overall configuration of the MIMO system according to the second embodiment. This MIMO system is an STC-SFN polarization system, and includes a transmission device 103 provided in the A station, a transmission device 104 provided in the B station, and the measuring device 2. The transmission apparatus 103 includes two transmission antennas 113 and 114, the transmission apparatus 104 includes two transmission antennas 115 and 116, and the measuring instrument 2 includes two reception antennas 4 and 5. The four transmission antennas 113 to 116 and the two reception antennas 4 and 5 constitute a 4 × 2 polarization MIMO system as a whole. The transmission antennas 113 and 115 and the reception antenna 4 are antennas for H polarization, and the transmission antennas 114 and 116 and the reception antenna 5 are antennas for V polarization.

  Transmitting apparatuses 103 and 104 generate OFDM signals including SP signals orthogonal to each other, and transmit broadcast waves from transmitting antennas 113 to 116, respectively. The transmission apparatus 103 transmits H polarization from the transmission antenna 113 and transmits V polarization from the transmission antenna 114. In addition, the transmission apparatus 104 transmits H polarization from the transmission antenna 115 and transmits V polarization from the transmission antenna 116. In the transmission path from the transmitting device 103 and the transmitting device 104 to the measuring instrument 2, the respective SP signals are superimposed.

  FIG. 7 is a diagram for explaining an example of an SP pattern used in the second embodiment, and shows an SP pattern in which positive and negative inversion pilots and a null pilot are combined. FIG. 7 (1) is an example of an SP pattern used for the transmission antenna 113 system (system in which H polarization is transmitted) of the transmission apparatus 103 provided in the A station. FIG. 7B is an example of an SP pattern used for the transmission antenna 114 system (system in which V polarization is transmitted) of the transmission apparatus 103 provided in the station A. FIG. 7 (3) is an example of an SP pattern used for the transmission antenna 115 system (system in which H polarization is transmitted) of the transmission apparatus 104 provided in the B station. FIG. 7 (4) is an example of an SP pattern used for the system of transmission antennas 116 of the transmission apparatus 104 provided in the B station (system in which V polarization is transmitted). The horizontal axis indicates the carrier direction, and the vertical axis indicates the symbol direction. Black circles and black squares indicate positive SP signals (1 + 0j), circles and squares with crosses indicate negative SP signals (-1 + 0j), and white circles and white squares indicate null SP signals (0 + 0j). .

  As shown in FIGS. 7 (1) to (4), SP signals are arranged in each symbol, and are arranged at 12 intervals in the carrier direction in the same symbol. 7 (1) and 7 (3), positive SP signals and null SP signals are alternately arranged at intervals of 24. 7 (2) and 7 (4), positive or negative SP signals and null SP signals are alternately arranged. There are 48 positive or negative SP signals, and 24 null SP signals.

  In addition, the SP signals are arranged every three carriers in a plurality of symbols, and are arranged at intervals of four symbols in the symbol direction in the same carrier. 7 (1) and 7 (3), the positive SP signal and the null SP signal are alternately arranged at intervals of 8 symbols. 7 (2) and 7 (4), positive or negative SP signals and null SP signals are alternately arranged. A positive or negative SP signal is 16 symbol intervals, and a null SP signal is 8 symbol intervals. Further, assuming that the interval after SP signal carrier direction interpolation is Dx and the symbol direction interval is Dy, FIG. 7 shows (Dx, Dy) = (3, 4) as an example of these combinations. On the other hand, various combinations such as (Dx, Dy) = (6, 2), (6, 4) may be used.

  In this way, the SP signal is configured in a pattern with a period of 16 symbols, and the SP signals in FIGS. 7 (1) to (4) are orthogonal. The orthogonal SP signal pattern may be any orthogonal pattern as long as each component of the SP signal can be separated individually. By using such orthogonal SP signals, the transmitting antennas 113 and 114 provided in the transmitting device 103 of the A station and the transmitting antennas 115 and 116 provided in the transmitting device 104 of the B station are used to receive the receiving antenna 4 of the measuring device 2. , 5 can be obtained individually.

FIG. 8 is a diagram illustrating the transmission path response of each path in the second embodiment. In the MIMO system shown in FIG. 6, eight paths are formed between the transmitting apparatus 103 of the A station, the transmitting apparatus 104 of the B station, and the measuring device 2. The transmission path response of the path from the transmission antenna 113 of the transmission apparatus 103 to the reception antenna 4 of the measuring instrument 2 is _defined as a _HH, and the transmission path response of the path from the transmission antenna 113 of the transmission apparatus 103 to the reception antenna 5 of the measurement apparatus 2 is defined as a _HV . Also, the transmission path responses of the path from the transmission antenna 114 of the transmission apparatus 103 to the reception antennas 4 and 5 of the measuring instrument 2 are a _VH and a _VV , respectively. Similarly, the transmission path responses of the path from the transmission antenna 115 of the transmission device 104 to the reception antennas 4 and 5 of the measuring device 2 are respectively b _HH and b _HV, and the transmission antenna 116 of the transmission device 104 to the reception antenna of the measurement device 2. The transmission path responses of the paths to 4 and 5 are b _VH and b _VV , respectively.

The H polarization transmitted from the transmission antenna 113 of the transmission apparatus 103 is transmitted to the reception antenna 4 of the measuring instrument 2 via the path of the transmission path response a _HH and transmitted from the transmission antenna 114 of the transmission apparatus 103. The wave is transmitted to the receiving antenna 4 of the measuring instrument 2 via the path of the transmission path response a _VH . Further, the H polarization transmitted from the transmission antenna 115 of the transmission device 104 is transmitted to the reception antenna 4 of the measuring device 2 via the transmission path response b _HH and transmitted from the transmission antenna 116 of the transmission device 104. The V polarized wave is transmitted to the receiving antenna 4 of the measuring instrument 2 through the path of the transmission path response b _VH . At this time, in the transmission path from the transmission apparatuses 103 and 104 to the measuring instrument 2, the SP signal from the transmission antenna 113 of the transmission apparatus 103, the SP signal from the transmission antenna 114 of the transmission apparatus 103, and the transmission antenna 115 of the transmission apparatus 104 And the SP signal from the transmission antenna 116 of the transmission apparatus 104 are superimposed.

The H polarization transmitted from the transmission antenna 113 of the transmission apparatus 103 is transmitted to the reception antenna 5 of the measuring instrument 2 via the path of the transmission path response a _HV , and the V polarization transmitted from the transmission antenna 114 of the transmission apparatus 103 is transmitted. The wave is transmitted to the receiving antenna 5 of the measuring instrument 2 through the path of the transmission path response a _VV . Further, the H polarization transmitted from the transmission antenna 115 of the transmission device 104 is transmitted to the reception antenna 5 of the measuring device 2 through the transmission path response b _HV and transmitted from the transmission antenna 116 of the transmission device 104. The V polarized wave is transmitted to the receiving antenna 5 of the measuring instrument 2 via the path of the transmission path response b _VV . At this time, in the transmission path from the transmission apparatuses 103 and 104 to the measuring instrument 2, the SP signal from the transmission antenna 113 of the transmission apparatus 103, the SP signal from the transmission antenna 114 of the transmission apparatus 103, and the transmission antenna 115 of the transmission apparatus 104 And the SP signal from the transmission antenna 116 of the transmission apparatus 104 are superimposed.

Returning to FIG. 6, the measuring device 2 receives broadcast waves from the transmission antennas 113 and 114 of the transmission apparatus 103 and broadcast waves from the transmission antennas 115 and 116 of the transmission apparatus 104 by the reception antennas 4 and 5. And the measuring device 2 extracts each SP signal from the superimposed signal using the orthogonality of the SP signal, and obtains the transmission path responses a _HH , a _VH , b _HH , b _VH of the system of the receiving antenna 4. At the same time, the transmission path responses a _HV , a _VV , b _HV , b _VV of the system of the receiving antenna 5 are obtained.

The measuring device 2 calculates power based on the transmission path responses _aHH , _aVH , _bHH , _bVH , _aHV , _aVV , _bHV , _bVV , and calculates the DU ratio from the calculated power. Thereby, the DU ratio with the reception antennas 4 and 5 of the measuring device 2 as reception points is calculated.

[Measuring instrument 2 / Example 2]
Next, the measuring device 2 shown in FIG. 6 will be described in detail. FIG. 9 is a block diagram illustrating a configuration example of the measuring device 2 according to the second embodiment. The measuring instrument 2 includes receiving antennas 4 and 5, components of the receiving antenna 4 system, components of the receiving antenna 5 system, and a DU ratio calculating unit 25. The system of the reception antenna 4 includes an effective symbol period extraction unit 21-1, an FFT unit 22-1, an SP extraction unit 23-1, and an SP interpolation unit 24-1, and the system of the reception antenna 5 includes an effective symbol period extraction unit. 21-2, an FFT unit 22-2, an SP extraction unit 23-2, and an SP interpolation unit 24-2.

  FIG. 9 shows only the components directly related to the present invention, and the components such as a symbol synchronization unit not directly related to the present invention are omitted. The processing of each component of the system of the receiving antenna 4 and the processing of each component of the system of the receiving antenna 5 are the same as the components that process the conventional OFDM signal.

  The effective symbol period extraction units 21-1 and 21-2 perform the same processing as the effective symbol period extraction unit 11 illustrated in FIG. 4, and the FFT units 22-1 and 22-2 perform the same processing as the FFT unit 12. The SP extraction units 23-1 and 23-2 perform the same process as the SP extraction unit 13, and the SP interpolation units 24-1 and 24-2 perform the same process as the SP interpolation unit 14. The processing of these components will be omitted.

  When the measuring device 2 receives the broadcast waves transmitted from the transmission device 103 and the transmission device 104 by the reception antenna 4, the H-polarized OFDM signal is processed by the system of the reception antenna 4. When the measuring device 2 receives broadcast waves transmitted from the transmission device 103 and the transmission device 104 by the reception antenna 5, the V-polarized OFDM signal is processed by the system of the reception antenna 5.

SP interpolation unit 24-1, channel response a _HH based on the SP signal after the interpolation, a _VH, b _HH, seeking b _VH, channel response _{a HH, a VH, b HH} , the b _VH DU ratio It outputs to the calculation part 25. SP interpolation unit 24-2, channel response a _HV based on the SP signal after the interpolation, a _VV, b _HV, seeking b _VV, channel response _{a HV, a VV, b HV} , the b _VV DU ratio It outputs to the calculation part 25.

The DU ratio calculation unit 25 inputs the transmission line responses a _HH , a _VH , b _HH , and b _VH from the SP interpolation unit 24-1, and transmits the transmission line responses a _HV , a _VV , b from the SP interpolation unit 24-2. Input _HV and b _VV . The DU ratio calculating unit 25 integrates the transmission path responses _aHH , _aVH , _bHH , _bVH , _aHV , _aVV , _bHV , _bVV in the carrier direction to obtain power, and based on the power The DU ratio is calculated, and the DU ratio is output to a display device or the like.

FIG. 10 is a diagram illustrating examples of transmission path responses a _HH , a _VV , a _HV , and a _VH with the station A in the second embodiment. The horizontal axis indicates the frequency (MHz) with the carrier center being 0 MHz, and corresponds to the carrier number. The vertical axis represents the amplitudes (dB) of the transmission line responses a _HH , a _VV , a _HV , and a _VH .

In each carrier, the amplitudes of the transmission path responses a _VH and a _HV are smaller than the transmission path responses a _HH and a _VV . This is for the channel response a _VH, is because the power of the reception antenna 4 in the vertical polarization for horizontal polarization is small, the transmission path for the response a _VH, receiving antenna 5, the horizontal polarization for vertical polarization This is because the power of the wave is small. Electric power is obtained by integrating the transmission path responses a _HH , a _VV , a _HV , and a _VH in the carrier direction.

Returning to FIG. 9, the DU ratio calculation unit 25 performs the same processing as the processing example of the DU ratio calculation unit 15 illustrated in FIG. 5. First, DU ratio calculation unit 25, channel response a _HH from SP interpolation unit _{24-1,24-2, a VH, b HH,} b VH, a HV, a VV, b HV, enter the b _VV ( Step S501). Then, the DU ratio calculation unit 25 integrates the transmission path responses a _HH , a _VH , b _HH , b _VH , a _HV , a _VV , b _HV , and b _VV of all the carriers after interpolation in the carrier direction, respectively. The broadcast wave power _PaHH , _PaVH , _PbHH , _PbVH , _PaHV , _PaVV , _PbHV , _PbVV is calculated.

The power Pa _HH indicates the power of the broadcast wave in the path from the transmission antenna 113 of the transmission device 103 to the reception antenna 4 of the measuring device 2, and the power Pa _VH is the transmission antenna 114 of the transmission device 103 to the reception antenna of the measurement device 2. 4 shows the power of the broadcast wave in the route to 4. The power Pb _HH indicates the power of the broadcast wave in the path from the transmission antenna 115 of the transmission device 104 to the reception antenna 4 of the measuring device 2, and the power Pb _VH is the reception antenna of the measurement device 2 from the transmission antenna 116 of the transmission device 104. 4 shows the power of the broadcast wave in the route to 4.

The power Pa _HV indicates the power of the broadcast wave in the path from the transmission antenna 113 of the transmission device 103 to the reception antenna 5 of the measuring device 2, and the power Pa _VV is from the transmission antenna 114 of the transmission device 103 to the measuring device 2. The electric power of the broadcast wave in the path | route to the receiving antenna 5 is shown. The power Pb _HV indicates the power of the broadcast wave in the path from the transmission antenna 115 of the transmission device 104 to the reception antenna 5 of the measuring device 2, and the power Pb _VV is the reception antenna of the measurement device 2 from the transmission antenna 116 of the transmission device 104. 5 shows the power of the broadcast wave on the route to 5.

The DU ratio calculation unit 25 transmits the sum of the broadcast wave powers Pa _HH , Pa _VH , Pa _HV , and Pa _VV transmitted from the transmitting device 103 of the A station from the transmitting device 104 of the B station using the following formula. The DU ratio of the broadcast wave between the A and B stations is calculated by dividing by the sum of the broadcast wave powers Pb _HH , Pb _VH , Pb _HV and Pb _VV . Then, the DU ratio calculation unit 15 outputs the DU ratio to a display unit or the like.
[Equation 2]
DU ratio = ( _PaHH + _PaVH + _PaHV + _PaVV ) / ( _PbHH + _PbVH + _PbHV + _PbVV )
... (2)
This DU ratio is a ratio when a broadcast wave from the transmitting apparatus 103 of the A station is a desired wave and a broadcast wave from the transmitting apparatus 104 of the B station is a wave from other than the desired station.

  The DU ratio calculation unit 25 replaces the denominator and the numerator of the equation (2) so that the broadcast wave from the transmission device 104 of the B station is a desired wave and the broadcast wave from the transmission device 103 of the A station is other than the desired station. Alternatively, the DU ratio may be calculated when the wave is a wave.

Further, the DU ratio calculation unit 25 uses the following formula to determine the H-polarized power Pa _HH , Pa received by the receiving antenna 4 of the measuring device 2 among the broadcast waves transmitted from the transmitting apparatus 103 of the A station. the sum of _VH, of the transmission broadcast wave from the transmitting device 104 of the B station, power Pb _HH of the H-polarized wave received by the receiving antenna 4 of the measuring device 2 by dividing the sum of Pb _VH, a , The DU ratio of the H polarization between the B stations may be calculated. Thereby, the DU ratio with the reception antenna 4 of the measuring device 2 as the reception point is calculated.
[Equation 3]
DU ratio = (Pa _HH + Pa _VH ) / (Pb _HH + Pb _VH ) (3)

Further, the DU ratio calculation unit 25 uses the following formula to determine the V-polarized power Pa _HV , Pa received by the receiving antenna 5 of the measuring device 2 among the broadcast waves transmitted from the transmitting apparatus 103 of the A station. the sum of _VV, among the transmitted broadcast wave from the transmitting device 104 of the B station, power Pb _HV of V-polarized wave received by the receiving antenna 5 of the measuring device 2 by dividing the sum of Pb _VV, a , The DU ratio of the V polarization between the B stations may be calculated. Thereby, the DU ratio with the reception antenna 5 of the measuring device 2 as the reception point is calculated.
[Equation 4]
DU ratio = (Pa _HV + Pa _VV ) / (Pb _HV + Pb _VV ) (4)

Further, the DU ratio calculation unit 25 may calculate the DU ratio between the A and B stations by the following formula. Thereby, the DU ratio with the reception antenna 4 or the reception antenna 5 of the measuring device 2 as the reception point is calculated.
[Equation 5]
DU ratio = Pa _HH / Pb _HH (5)
[Equation 6]
DU ratio = Pa _HV / Pb _HV (6)
[Equation 7]
DU ratio = Pa _VH / Pb _VH (7)
[Equation 8]
DU ratio = Pa _VV / Pb _VV (8)

  The DU ratio calculation unit 25 may calculate the DU ratio by exchanging the denominator and the numerator of the equations (3) to (8).

As described above, according to the measuring instrument 2 of the second embodiment, the SP signals orthogonal to the transmission antennas 113 and 114 included in the transmission device 103 of the A station and the transmission antennas 115 and 116 included in the transmission device 103 of the B station. H polarization and V polarization are transmitted, respectively, and H polarization and V polarization on which SP signals are superimposed are received. The SP extraction units 23-1 and 23-2 extract the SP signal from the carrier symbol of the received OFDM signal, and the SP interpolation units 24-1 and 24-2 use the orthogonality of the SP signal to perform SP. The signals are interpolated to obtain transmission path responses _aHH , _aVH , _bHH , _bVH , _aHV , _aVV , _bHV , _bVV . The DU ratio calculation unit 25 integrates the transmission line responses a _HH , a _VH , b _HH , b _VH , a _HV , a _VV , b _HV , and b _VV in the carrier direction to obtain power, and calculates the DU ratio. To do.

  Thus, by using orthogonal SP signals that are separable from each other, the DU ratio between the A and B stations can be measured without stopping the signals of the A and B stations.

  In addition, as a hardware configuration of the measuring instrument 1 of the first embodiment and the measuring instrument 2 of the second embodiment, a normal computer can be used. The measuring instruments 1 and 2 are constituted by a computer having a volatile storage medium such as a CPU and a RAM, a non-volatile storage medium such as a ROM, an interface, and the like. Each function of the effective symbol period extraction unit 11, the FFT unit 12, the SP extraction unit 13, the SP interpolation unit 14, and the DU ratio calculation unit 15 included in the measuring instrument 1 causes the CPU to execute a program describing these functions. It is realized by each. Also, the effective symbol period extraction units 21-1 and 21-2, the FFT units 22-1 and 22-2, the SP extraction units 23-1 and 23-2, and the SP interpolation units 24-1 and 24 included in the measuring device 2. -2 and the DU ratio calculation unit 25 are each realized by causing the CPU to execute a program describing these functions. These programs are stored in the storage medium and read out and executed by the CPU. These programs can also be stored and distributed in a storage medium such as a magnetic disk (floppy (registered trademark) disk, hard disk, etc.), optical disk (CD-ROM, DVD, etc.), semiconductor memory, etc. You can also send and receive.

  The present invention has been described with reference to the first and second embodiments. However, the present invention is not limited to the first and second embodiments, and various modifications can be made without departing from the technical idea thereof. For example, the SP patterns shown in FIGS. 2 and 7 are examples, and the present invention is not limited to this SP pattern, and other SP patterns may be used. In short, the SP pattern only needs to be orthogonal between the paths, and the SP signals only need to be arranged so that the measuring instruments 1 and 2 can calculate the transmission path response of each path using the orthogonal SP signals. . Further, a pilot signal other than the SP signal may be used.

  In the first embodiment, the case where the transmitting station is the A station and the B station has been described as an example. However, the present invention is also applicable to the case where there are three or more transmitting stations. That is, the present invention is applicable to an n × 1 MISO system (n is a positive integer of 2 or more). In this case, the DU ratio calculation unit 15 of the measuring instrument 1 inputs the transmission path response of the n path, integrates the transmission path response of the n path in the carrier direction, and obtains the power of the n path. Then, the DU ratio calculation unit 15 includes power in a path to a predetermined one transmitting station and power in a path to a transmitting station other than the predetermined one transmitting station among n path powers ( The ratio with the sum of power when there are a plurality of such routes is calculated as the DU ratio.

  In the first embodiment, the example of the MISO system using the same polarization has been described. However, the present invention is applicable to a MISO system using different polarizations, a spatial MISO system not using polarization, and the like. There is. In the second embodiment, an example of a MIMO system using both polarized waves has been described. However, the present invention is also applicable to a spatial MIMO system, a directional MIMO system, and the like that do not use polarized waves. In the present invention, it is possible to use the same polarization in the MISO system and the MIMO system by taking a sufficient distance between the antennas and lowering the correlation.

  In the second embodiment, the example of the polarization method using the H polarization and the V polarization has been described. However, the present invention can be applied to the case where the MIMO method using another polarization (for example, circular polarization) is used. Is also applicable. In the second embodiment, the case where the transmitting station is the A station and the B station has been described as an example. However, the present invention is also applicable to the case where there are three or more transmitting stations. That is, the present invention is applicable to a 2n × 2 polarization MIMO system (n is a positive integer of 2 or more). In this case, the DU ratio calculation unit 25 of the measuring device 2 inputs transmission path responses of a plurality of paths in the 2n × 2 polarization MIMO system, and integrates the transmission path responses of the plurality of paths in the carrier direction. Ask for power. Then, the DU ratio calculation unit 25 uses the power in the path between the predetermined one transmission station and the power in the path between the predetermined one transmission station and the power among the plurality of paths. A ratio with (the sum of electric power when there are a plurality of the paths) is calculated as a DU ratio. The DU ratio may be calculated for each polarization of the same type, such as H polarization or V polarization. The present invention is also applicable to a 4 × 4 MIMO system, for example.

  In the first and second embodiments, examples of the measuring devices 1 and 2 have been described. However, the present invention is also applicable to a receiving device. The receiving apparatus includes the constituent unit of the first embodiment shown in FIG. 4 or the constituent unit of the second embodiment shown in FIG. 9, calculates the DU ratio, and demodulates the received OFDM signal.

  In the first embodiment, the processing of each component from the effective symbol period extraction unit 11 to the DU ratio calculation unit 15 of the measuring instrument 1 in the first embodiment shown in FIG. It may be realized by an LSI chip which is a circuit. These may be individually made into one chip, or a part or all of them may be made into one chip.

  Further, instead of the LSI, it may be realized by a chip such as a VLSI or ULSI having a different degree of integration. Furthermore, the present invention is not limited to a chip such as an LSI, and a dedicated circuit or a general-purpose processor may be used, or an FPGA (Field Programmable Gate Array) may be used. The same applies to the processing of each component from the effective symbol period extraction units 21-1, 21-2 to the DU ratio calculation unit 25 of the measuring instrument 2 in the second embodiment shown in FIG. This is realized by a chip.

1, 2 Measuring instruments 3 to 5 Receiving antennas 11, 21-1, 21-2 Effective symbol period extraction units 12, 22-1, 22-2 FFT units 13, 23-1, 23-2 SP extraction units 14, 24 -1,24-2 SP interpolation units 15 and 25 DU ratio calculation units 101 to 104 Transmission devices 111 to 116 Transmission antenna

Claims (6)

In a measuring device that receives broadcast waves transmitted from a plurality of transmitting stations and measures a DU ratio (a ratio between a wave from a desired station and a wave from other than the desired station) of the broadcast wave,
Broadcast waves including pilot signals orthogonal to each other are transmitted from the plurality of transmitting stations,
An SP extraction unit for extracting a pilot signal from a carrier symbol of a broadcast wave on which the orthogonal pilot signal is superimposed;
An SP interpolation unit that interpolates the pilot signal extracted by the SP extraction unit and obtains a transmission path response for each path from the plurality of transmitting stations to the measuring device;
Integrating a transmission path response for each path obtained by the SP interpolation section in a carrier direction, obtaining power for each path, and calculating the DU ratio based on the power for each path;
A measuring instrument comprising: The measuring instrument according to claim 1, wherein
When receiving broadcast waves from a plurality of transmitting stations via a MISO (Multiple Input Single Output) system path,
The SP interpolation unit obtains transmission path responses of a plurality of paths in the MISO system,
The DU ratio calculation unit integrates transmission path responses of a plurality of paths obtained by the SP interpolation unit in a carrier direction to obtain powers of the plurality of paths, and among the powers of the plurality of paths, a predetermined 1 A measuring device, characterized in that a ratio of power in a path to one transmitting station and power in a path to a transmitting station other than the predetermined one transmitting station is calculated as the DU ratio. The measuring instrument according to claim 1, wherein
When receiving broadcast waves from a plurality of transmitting stations via a MIMO (multiple input multiple output) system path,
The SP interpolation unit obtains transmission path responses of a plurality of paths in the MIMO system,
The DU ratio calculation unit integrates transmission path responses of a plurality of paths obtained by the SP interpolation unit in a carrier direction to obtain powers of the plurality of paths, and among the powers of the plurality of paths, a predetermined 1 A measuring device, characterized in that a ratio of power in a path to one transmitting station and power in a path to a transmitting station other than the predetermined one transmitting station is calculated as the DU ratio. The measuring instrument according to claim 3,
When receiving different polarizations from the plurality of transmitting stations via a MIMO (multiple input multiple output) system path,
A new DU ratio calculation unit that replaces the DU ratio calculation unit integrates transmission path responses in a plurality of paths to a receiving antenna that receives a predetermined type of polarization in the carrier direction, and obtains the power of each of the plurality of paths. The ratio of the power in the path to the predetermined one transmitting station and the power in the path to the transmitting station other than the predetermined one among the powers of the plurality of paths is the predetermined power. A measuring instrument characterized in that it is calculated as the DU ratio of the type of polarization. In a chip mounted on a device that receives broadcast waves transmitted from a plurality of transmitting stations,
Broadcast waves including pilot signals orthogonal to each other are transmitted from the plurality of transmitting stations,
An SP extraction unit for extracting a pilot signal from a carrier symbol of a broadcast wave on which the orthogonal pilot signal is superimposed;
An SP interpolation unit that interpolates the pilot signal extracted by the SP extraction unit and obtains a transmission path response for each path from the plurality of transmission stations to the device;
The transmission path response for each path obtained by the SP interpolation unit is integrated in the carrier direction to obtain the power for each path, and based on the power for each path, the DU ratio of the broadcast wave (the wave from the desired station) A DU ratio calculation unit for calculating a ratio between waves from other than the desired station),
A chip characterized by comprising: A program for an apparatus for receiving a broadcast wave including orthogonal pilot signals from a plurality of transmitting stations,
Extracting a pilot signal from a carrier symbol of a broadcast wave on which the orthogonal pilot signal is superimposed;
Interpolating the pilot signal and obtaining a transmission path response for each path from the plurality of transmitting stations to the apparatus; and
Integrating the transmission path response for each path in the carrier direction to determine the power for each path;
Calculating a DU ratio of the broadcast wave (ratio between a wave from a desired station and a wave from other than the desired station) based on the power for each path;
A program that causes a computer to execute.