JP2016106443A - Transmitting device and receiving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmitting device and a receiving device capable of suppressing deterioration in reception performance low even when the directivity is changed.SOLUTION: A transmitting device 1 comprises: an encoding unit 11 that performs error correction encoding; an interleaving unit 12; a modulator 13 that performs predetermined modulation processing to an interleaved signal; a directivity variable antenna 15 that can change a radiation pattern; a guard section insertion unit 14 that inserts a guard section not contributing to demodulation into a frame; and a directivity controller 16 that instructs the directivity variable antenna to change the radiation pattern, in the guard section inserted by the guard section insertion unit.SELECTED DRAWING: Figure 1

Description

The present invention relates to a transmission apparatus and a reception apparatus that perform wireless communication using a directional antenna having sharp directivity.

In wireless communication, time variation of radio propagation path characteristics called fading occurs due to the influence of reflection / diffraction due to weather conditions and structures, movement of a transmitting station and a receiving station, and the like. When a directional antenna with sharp directivity is used as a mobile station antenna, fading fluctuations become slow in time (slow fading), and received signal power may decrease over a long period of time. If the reception power reduction time is longer than the interleave length, it becomes difficult to randomize errors by interleaving, and the effect of powerful error correction codes such as convolutional codes and turbo codes, which are random error correction codes, cannot be obtained, resulting in degraded reception performance. To do.

For this problem, in Patent Document 1, by changing the directivity of the mobile station antenna with a time length shorter than the interleave length (frame length), pseudo fading fluctuation is given in the frame, and the effect of the error correction code is improved. It is improving.

Japanese Patent No. 9-270625

However, as described in Patent Document 1, if the directivity of the directional antenna is changed even with a short time length, the instantaneous amplitude and phase of the signal change discontinuously. That is, when the directivity of the transmission antenna is changed, the amplitude and phase of the transmission signal change discontinuously, and when the directivity of the reception antenna is changed, the amplitude and phase of the reception signal change discontinuously. Such signal discontinuity causes deterioration in reception performance. The present invention has been made in view of the above, and an object of the present invention is to obtain a transmission device and a reception device that can suppress deterioration of reception performance even when directivity is changed.

In order to solve the above-described problems and achieve the object, the transmission apparatus of the present invention includes a variable directivity antenna that can change a radiation pattern, a guard interval insertion unit that inserts a guard interval that does not contribute to demodulation, and a guard. In the guard section inserted by the section insertion unit, a directivity control unit that instructs the directivity variable antenna to change the radiation pattern is provided.

The transmitter of the present invention is inserted by a plurality of antennas, a selector that selects an antenna that transmits a signal from the plurality of antennas, a guard interval insertion unit that inserts a guard interval that does not contribute to demodulation to the frame, and a guard interval insertion unit In the guard interval, an antenna selection unit that instructs the selector to change the antenna is provided.

Further, the receiving apparatus of the present invention includes a directivity variable antenna, a synchronization unit that detects a guard interval that does not contribute to frame demodulation from a received signal received by the directivity variable antenna, and a directivity in the guard interval detected by the synchronization unit. A directivity control unit for instructing a radiation pattern to be changed with respect to the variable variable antenna.

The receiving apparatus of the present invention includes a synchronization unit that detects a guard interval that does not contribute to demodulation of a frame from a reception signal received by any one of a plurality of antennas or a plurality of antennas, and a guard interval detected by the synchronization unit. An antenna selection unit that changes an antenna that receives signals from a plurality of antennas.

The present invention has an effect that it is possible to suppress deterioration of reception performance at the time of change by changing the radiation pattern or the antenna in the guard section.

FIG. 1 is a diagram illustrating a configuration example of a transmission apparatus according to the first embodiment. FIG. 2 is a diagram illustrating a frame configuration example according to the first to sixth embodiments. FIG. 3 is a diagram illustrating a modification of the transmission apparatus according to the first embodiment. FIG. 4 is a diagram illustrating a configuration example of a transmission apparatus according to the second embodiment. FIG. 5 is a diagram illustrating a modification of the transmission apparatus according to the second embodiment. FIG. 6 is a diagram illustrating a configuration example of a transmission apparatus according to the third embodiment. FIG. 7 is a diagram illustrating a modification of the transmission apparatus according to the third embodiment. FIG. 8 is a diagram illustrating a configuration example of a receiving apparatus according to the fourth embodiment. FIG. 9 is a diagram illustrating a configuration example of a receiving apparatus according to the fifth embodiment. FIG. 10 is a diagram illustrating a configuration example of a receiving apparatus according to the sixth embodiment. FIG. 11 is a diagram illustrating a modification of the receiving apparatus according to the sixth embodiment. FIG. 12 is a diagram illustrating a modification of the frame configuration of the first to sixth embodiments. FIG. 13 is a diagram illustrating a modification of the frame configuration of the first to sixth embodiments. FIG. 14 is a diagram illustrating a modification of the frame configuration of the first to sixth embodiments. FIG. 15 is a diagram illustrating a modification of the frame configuration of the first to sixth embodiments. FIG. 16 is a diagram illustrating a modification of the frame configuration of the first to sixth embodiments.

Hereinafter, embodiments of a communication device, a transmission device, and a reception device according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1
FIG. 1 is a diagram illustrating a configuration of a transmission device 1 according to the present embodiment. The transmission device 1 constitutes a transmission part of a communication device that transmits and receives radio signals. The communication device is movable, for example, a mobile station of a mobile communication system. The transmission apparatus 1 includes an encoding unit 11, an interleaving unit 12, a modulation unit 13, a guard interval insertion unit 14, a directivity variable antenna 15, and a directivity control unit 16, which will be described later.

FIG. 2 is a diagram illustrating an example of a frame format when the transmission apparatus 1 transmits a signal in the present embodiment. The frame 2 includes radiation pattern A data 21, a guard interval (Guard Time) 22 corresponding to a radiation pattern change period, and radiation pattern B data 23. Although the frame length of frame 2 in the present embodiment is described as being the same as the interleave length, the present invention is not limited to this.

In the present embodiment, for simplicity of explanation, the number of guard sections 22 is described as 1. However, the number of guard sections 22 may be two or more. The guard section 22 is described as being in the center of the frame 2, but the guard section 22 may be anywhere in the frame 2.

In the transmission apparatus 1, the encoding unit 11 performs error correction encoding on a transmission bit sequence that is an input signal. The error correction coding method may be any error correction coding method such as a convolutional code, a turbo code, or an LDPC (Low Density Parity Check) code. The interleaving unit 12 performs an interleaving process on the signal encoded by the encoding unit 11. The modulation unit 13 performs a predetermined modulation process on the signal interleaved by the interleaving unit 12. The guard interval insertion unit 14 inserts a guard interval 22 that does not contribute to data transmission into the signal modulated by the modulation unit 13 and notifies the directivity control unit 16 of the guard interval insertion position. Since the guard section 22 does not contribute to data transmission, it may be any signal, a copy of the data portion, a random sequence, or ‘0’ (no transmission). The directivity variable antenna 15 transmits a signal after insertion of a guard section to a communication partner radio apparatus (not shown, hereinafter referred to as an opposite apparatus). The directivity variable antenna 15 has a sharp directivity, and can change the radiation pattern as in APAA (Active Phased Array Antenna). The directivity control unit 16 controls the directivity of the variable directivity antenna 15 and changes the radiation pattern of the variable directivity antenna 15.

Next, the operation of the directivity control unit 16 will be described. Guard section insertion position information that is a guard section insertion position is received from the guard section insertion unit 14. Next, based on this guard section insertion position information, a change instruction signal for changing the radiation pattern at the guard section insertion position is output to the directivity variable antenna 15.

In this way, by changing the radiation pattern of the variable directivity antenna in the guard section 22 that does not contribute to data transmission, it is possible to eliminate the influence of the discontinuity of the transmission signal due to the radiation pattern change on the data portion. Thus, it is possible to suppress the reception performance degradation when changing the radiation pattern.

In addition, although the guard interval insertion unit 14 and the directivity control unit 16 have been described as notifying the guard interval insertion position from the guard interval insertion unit 14 to the directivity control unit 16 as a synchronization method, the present invention is not limited to this. . As another example of the synchronization method of the guard interval insertion unit 14 and the directivity control unit 16, the transmission device 1 further includes a transmission control unit 17 that manages the operation timing of the entire transmission device 1, as shown in FIG. You may make it notify the guard area insertion position information which is the information of a guard area insertion position from the transmission control part 17 to the guard area insertion part 14 and the directivity control part 16.

Embodiment 2
In the first embodiment, a transmission apparatus provided with a single directivity variable antenna has been described. In this embodiment, a transmission apparatus provided with a plurality of fixed directivity antennas will be described. In the present embodiment, parts different from those of transmitting apparatus 1 in Embodiment 1 will be described.

FIG. 4 is a diagram illustrating an example of the transmission apparatus according to the second embodiment. 4 adds selector 31 to transmission device 1 described in the first embodiment, directivity control unit 16 as antenna selection unit 35, and directivity variable antenna 15 is fixed in directivity. The antennas 32 to 34 are respectively replaced.

In the transmission device 1a, the directional fixed antennas 32 to 34 are arranged so that the radiation patterns are in different directions. Here, the directivity fixed antennas 32 to 34 are different from the directivity variable antenna 15 in the first embodiment in order to arrange the directivity fixed antennas 32 to 34 so that the radiation patterns are in different directions. Need not be changeable. However, it is assumed that the directivity fixed antennas 32 to 34 have a sharp directivity similar to the directivity variable antenna 15.

The selector 31 outputs the output signal of the guard interval insertion unit 14 to one of the directivity fixed antennas 32 to 34 designated by the antenna selection unit 35. In addition, the directivity fixed antennas 32 to 34 not designated by the antenna selection unit 35 are set to 0 output (no output signal). The directional fixed antennas 32 to 34 transmit the output signal of the selector 31 to the opposing device (not shown). Here, the selector 31 has been described as selecting one of the directional fixed antennas 32 to 34, but the present invention does not limit the number of antennas to be selected.

The antenna selection unit 35 selects a directional fixed antenna to be used for transmission from among the directional fixed antennas 32 to 34 and notifies the selector 31 of it. By this notification, the antenna selection unit 35 changes the directivity fixed antenna to be selected at the insertion position of the guard section 22 in the frame 2 notified from the guard section insertion unit 14.

Thus, by changing the directional fixed antenna in the guard section 22 that does not contribute to data transmission, it is possible to remove the influence of the discontinuity of the transmission signal accompanying the change of the directional fixed antenna on the data portion, Thereby, it is possible to suppress the reception performance deterioration due to the change of the directional fixed antenna.

Although the number of directional fixed antennas has been described as three, the number of antennas is not limited to this, and the same effect can be obtained even when the number of directional fixed antennas is N (N is an integer of 2 or more). .

In addition, although the method of notifying the guard interval insertion position from the guard interval insertion unit 14 to the antenna selection unit 35 has been described as a synchronization method of the guard interval insertion unit 14 and the antenna selection unit 35, the present invention is not limited to this. As another example of the synchronization method of the guard interval insertion unit 14 and the antenna selection unit 35, as shown in FIG. 5, the transmission device 1a further includes a transmission control unit 36 that manages the operation timing of the entire transmission device 1a, The control section 36 may notify the guard section insertion section 14 and the antenna selection section 35 of the guard section insertion position.

Embodiment 3
In the second embodiment, the transmission apparatus including a plurality of directional fixed antennas that do not change the radiation pattern has been described. However, in the present embodiment, the transmission apparatus including a plurality of directional variable antennas that can change the radiation pattern. Will be described.

In the present embodiment, parts different from those of transmitting apparatus 1 in Embodiment 1 will be described. 6 adds a directivity variable antenna 43 to the transmission apparatus 1 described in the first embodiment, inserts the modulation unit 13 into the modulation unit 41, and inserts the guard interval insertion unit 14 into the guard interval. The directivity control unit 16 is replaced with the directivity control unit 44 in the unit 42.

Also, the output signal from the modulation unit 41 is divided into two signals, a first modulation unit output signal and a second modulation unit output signal, and is input to the guard interval insertion unit 42. The guard interval insertion unit 42 inserts a guard interval into the input first modulation unit output signal and outputs it to the directivity variable antenna 15 as a first guard interval insertion signal. A guard interval is inserted into the modulation unit output signal and is output to the directivity variable antenna 43 as a second guard interval insertion signal. The directivity variable antenna 15 and the directivity variable antenna 43 each change a radiation pattern according to an instruction from the directivity control unit 44 and transmit a transmission signal.

The modulation unit 41 performs a predetermined modulation process on the output signal of the interleaving unit 12, and outputs a first modulation signal and a second modulation signal, which are modulation signals for two antennas (directivity variable antennas 15 and 43). Generate. The guard interval insertion unit 42 inserts the guard interval 22 in the same manner as the guard interval insertion unit 14 for each of the first modulation signal and the second modulation signal, which are modulation signals for two antennas, A section insertion signal and a second guard section insertion signal are generated. Then, the first guard interval insertion signal and the second guard interval insertion signal are output to the directivity variable antenna 15 and the directivity variable antenna 43, respectively, and the guard interval insertion position is notified to the directivity control unit 44. Directivity variable antennas 15 and 43 transmit signals after insertion of the guard interval to the opposing device (not shown). The directivity control unit 44 controls the directivity so that the directivity variable antennas 15 and 43 change the radiation pattern in the guard section 22 based on the guard section insertion position notified from the guard section insertion unit 42.

Next, the operation of the directivity control unit 44 will be described. The directivity control unit 44 controls the directivity of the directivity variable antennas 15 and 43 to change the radiation pattern. At this time, the directivity control unit 44 changes the radiation pattern of the directivity variable antennas 15 and 43 at the guard section insertion position in the frame 2 notified from the guard section insertion unit 42.

Regarding the change of the radiation pattern, the directivity control unit 44 changes the radiation pattern of the directivity variable antennas 15 and 43 so that the radiation patterns of the directivity variable antennas 15 and 43 after the directivity change are in different directions. Can be controlled.

As described above, in a transmitter including a plurality of directivity variable antennas, each directivity variable antenna independently changes the directivity fixed antenna in the guard section 22 that does not contribute to data transmission. The influence of the discontinuity of the transmission signal due to the antenna change on the data portion can be removed, and thereby the reception performance deterioration at the time of changing the radiation pattern can be suppressed.

In addition, although the number of directivity variable antennas has been described as two, the number of antennas is not limited to this, and the same effect can be obtained when the number of directivity variable antennas is N (N is an integer of 2 or more). .

When the number of directivity variable antennas is 3 or more, the directivity control unit 44 sets the radiation pattern of each directivity variable antenna so that at least one radiation pattern of each directivity variable antenna is in a different direction. If it is changed, it is possible to reduce the probability that the reception power of the transmission signals from the respective directivity variable antennas in the opposite device is all reduced, so that a transmission diversity effect can be obtained.

As a method of synchronizing the guard interval insertion unit 42 and the directivity control unit 44, the method of notifying the guard interval insertion position from the guard interval insertion unit 42 to the directivity control unit 44 has been described. However, the present invention is not limited to this. . As another example of the synchronization method of the guard interval insertion unit 42 and the directivity control unit 44, as illustrated in FIG. 7, the transmission device 1b further includes a transmission control unit 45 that manages the operation timing of the entire transmission device 1b. You may make it notify the guard area insertion part 42 and the directivity control part 44 from the transmission control part 45 to a guard area insertion position.

Embodiment 4
In Embodiments 1 to 3, the transmission apparatus 1 including a directional antenna has been described. In the present embodiment, a reception apparatus 5 including a directional antenna will be described.

As shown in FIG. 8, the receiving apparatus 5 of the present embodiment includes a variable directivity antenna 51, a directivity control unit 52, a synchronization unit 53, a demodulation unit 54, a deinterleave unit 55, and a decoding unit 56. .

In the receiving device 5, the variable directivity antenna 51 receives a signal transmitted from a counter device (not shown). The directivity variable antenna 51 has a sharp directivity, and the radiation pattern can be changed. The frame format in this embodiment is the same as the frame format in FIG.

The directivity control unit 52 controls the directivity of the directivity variable antenna 51. The synchronization unit 53 detects the position where the guard section 22 is inserted in the frame 2 from the signal received by the directivity variable antenna 51, and uses the section information indicating the guard section insertion position as guard section insertion position information. 52 is notified. The demodulator 54 demodulates the data portions 21 and 23 obtained by removing the guard section 22 from the signal received by the directivity variable antenna 51. The deinterleave unit 55 performs deinterleave processing on the signal demodulated by the demodulator 54. The decoding unit 56 performs error correction decoding processing on the signal deinterleaved by the deinterleaving unit 55 to obtain a final received signal.

Next, the operation of the directivity control unit 52 will be described. The directivity control unit 52 controls the directivity of the directivity variable antenna 51 to change the radiation pattern. At this time, the radiation pattern of the directivity variable antenna 51 is changed in the guard interval based on the guard interval insertion position information notified from the synchronization unit 53.

In this way, by changing the radiation pattern of the directional variable antenna in the guard interval that does not contribute to data transmission, the influence of the discontinuity of the received signal due to the radiation pattern change on the data part can be eliminated, thereby It is possible to suppress the reception performance degradation when changing the radiation pattern.

Embodiment 5
In the fourth embodiment, a receiving apparatus including a single directivity variable antenna has been described. In the present embodiment, a receiving apparatus including a plurality of fixed directivity antennas will be described.

The receiving apparatus 5a illustrated in FIG. 9 adds a selection / synthesis unit 66 to the receiving apparatus 5 illustrated in FIG. 8, the directivity variable antenna 51 is changed to the directivity fixed antennas 61 to 64, and the directivity control unit 52 is added. The antenna selector 65 is replaced with each one. In the present embodiment, parts different from those of the fourth embodiment will be described.

In the receiving device 5a, the directional fixed antennas 61 to 64 are arranged so that the radiation patterns are in different directions. Here, unlike the directivity variable antenna 51, the fixed directivity antennas 61 to 64 do not need to be able to change the radiation pattern. However, it is assumed that the fixed directivity antennas 61 to 64 have a sharp directivity similar to the variable directivity antenna 51.

The directional fixed antennas 61 to 64 receive signals transmitted from a counter device (not shown). Receiving signals received by the directional fixed antennas 61 to 64 are input to the selection combining unit 66. The selection / combination unit 66 selects one of received signals from the directional fixed antennas 61 to 64 or combines some of them according to an instruction from the antenna selection unit 65 and outputs the selected signal to the synchronization unit 53. As a combining method in the selection combining unit 66, all the reception signals from the directional fixed antennas 61 to 64 designated by the antenna selection unit 65 may be added, averaged, or according to the reception signal power. Weighted addition may be performed.

The antenna selection unit 65 selects a directional fixed antenna to be used for reception from the directional fixed antennas 61 to 64 and notifies the selection combining unit 66 of the selected directional fixed antenna. The directivity fixed antenna selection method of the antenna control unit 65 may be random, the directivity fixed antennas 61 to 64 may be periodically selected in order, and the reception power of the directivity fixed antennas 61 to 64 is large. An antenna may be selected. At this time, based on the information of the detected guard interval notified from the synchronization unit 53, control is performed to change the directional fixed antenna used in the guard interval.

In this way, by changing the directional fixed antenna to another directional fixed antenna in the guard interval that does not contribute to data transmission, the effect of the received signal discontinuity on the data part due to the change of the directional fixed antenna is affected. Accordingly, it is possible to suppress the reception performance deterioration due to the change of the directional fixed antenna.

Although the number of directional fixed antennas has been described as four, the number of antennas is not limited to this. The number of directional fixed antennas may be N (N is an integer of 2 or more).

Embodiment 6
In the fifth embodiment, the reception apparatus including a plurality of directional fixed antennas that do not change the radiation pattern has been described. However, in the present embodiment, the reception apparatus including a plurality of directional variable antennas that can change the radiation pattern. Will be described.

The receiving apparatus 5b illustrated in FIG. 10 adds a directivity variable antenna 71 and a synchronization unit 73 to the receiving apparatus 5 described in the fourth embodiment, and demodulates the directivity control unit 52 to the directivity control unit 72. The unit 53 is replaced with a demodulation unit 74.

The directivity variable antenna 71 has the same function as the directivity variable antenna 51, and the synchronization unit 73 has the same function as the synchronization unit 53. In the present embodiment, parts different from the fifth embodiment will be described.

Directivity variable antennas 51 and 71 receive a signal transmitted from a counter device (not shown). The reception signal received by the directivity variable antenna 51 is input to the synchronization unit 53, and the reception signal received by the directivity variable antenna 71 is input to the synchronization unit 73. The demodulator 74 performs a demodulation process corresponding to the modulation method of the opposite apparatus on the input signals.

The directivity control unit 72 controls the directivity of the directivity variable antennas 51 and 71 to change the radiation pattern. At this time, the radiation pattern of the directivity variable antenna 51 is changed in the guard section detected by the synchronization unit 53, and the radiation pattern of the directivity variable antenna 71 is changed in the guard section detected by the synchronization unit 73.

Further, the radiation patterns of the directivity variable antennas 51 and 71 after the radiation pattern change can be controlled to be in different directions.

FIG. 11 is a diagram illustrating a modification of the receiving apparatus in FIG. The receiving device 5c shown in FIG. 11 is obtained by replacing the receiving device 5b shown in FIG. 10 with the directivity control unit 72 replaced with the directivity control unit 81 and the synchronization units 53 and 73 with the synchronization unit 82. is there. The other constituent elements are the same as those provided in the above-described receiving device 5b.

In FIG. 10, the two synchronization units 53 and 73 are provided, and the guard interval is detected for each of the received signals received by the directivity variable antennas 51 and 71. However, in FIG. One guard interval position is detected from the received signal.

The synchronization unit 82 detects the guard section position from each received signal received by the directivity variable antennas 51 and 71. At this time, the guard section position output by the synchronization unit 82 is a value common to the received signals received by the directivity variable antennas 51 and 71. The directivity control unit 81 controls the directivity of the directivity variable antennas 51 and 71 to change the radiation pattern. At this time, the radiation patterns of the directivity variable antennas 51 and 71 are changed in the guard section detected by the synchronization unit 82. That is, the radiation patterns of the directivity variable antennas 51 and 71 are changed simultaneously. In addition, the radiation patterns of the directivity variable antennas 51 and 71 after the directivity change are controlled to be in different directions.

In this manner, in a receiver including a plurality of directional variable antennas, each directional variable antenna independently changes the radiation pattern of the directional variable antenna in the guard section 22 that does not contribute to data transmission. It is possible to remove the influence of the discontinuity of the received signal due to the change of the radiation pattern of the directivity variable antenna on the data portion, thereby suppressing the reception performance deterioration when the radiation pattern is changed. At the time of reception diversity, it is possible to eliminate the influence of the discontinuity of the received signal accompanying the change of the radiation pattern on the data portion. Further, at the time of spatial multiplexing, it is possible to remove the influence of the discontinuity of the received signal accompanying the change of the radiation pattern on the data portion for each stream.

Although the number of directional variable antennas has been described as two, the number of antennas is not limited to this, and the number of directional variable antennas may be N (N is an integer of 2 or more).

When the number of directivity variable antennas is 3 or more, the directivity control unit 81 sets the radiation pattern of each directivity variable antenna so that at least one radiation pattern of each directivity variable antenna has a different direction. If it is changed, it is possible to reduce the probability that the received power in each directional variable antenna is all reduced, so that it is possible to obtain a reception diversity effect.

FIG. 12 is a diagram illustrating a modification of the frame format according to the first to sixth embodiments. The frame format 2a shown in FIG. 12 is obtained by replacing the data 21 and 23 with an OFDM (Orthogonal Frequency Division Multiplexing) symbol 91 with respect to the frame 2 shown in FIG. The OFDM symbol 91 includes a guard interval (GI: Guard Interval) 92 and data 93. The guard interval 92 may be any signal such as a signal obtained by copying the latter half of the data 93 (cyclic prefix) or null (no transmission section).

When the frame format of FIG. 12 is used, the directivity control units 16, 44, 52, 72, 81 and the antenna selection units 35, 65 are not limited to the guard section 22 in the frame 2, and any guard in the frame 2 a In the interval 92, the radiation pattern of the directional variable antenna is changed or the directional fixed antenna used for transmission / reception is changed.

In FIG. 12, the number of OFDM symbols in the frame 2a is set to 4 for simplification of explanation, but the present invention is not limited to this. The number of OFDM symbols may be N (N is an integer of 2 or more).

In FIG. 12, the number of guard intervals for changing the radiation pattern is set to 1, but this is not restrictive. The number of guard intervals for changing the radiation pattern may be M (M is an integer of 2 or more).

Further, the OFDM symbol 91 in FIG. 12 may be anything as long as it uses a guard interval, such as an SC-FDMA (Single Carrier-Division Multiple Access) symbol.

With the configuration as described above, it is possible to obtain an effect that it is possible to suppress deterioration in reception performance when the radiation pattern of the directional antenna is changed or when the directional antenna is changed. Moreover, since it is not necessary to insert a guard interval, an effect of suppressing a decrease in transmission efficiency can be obtained.

FIG. 13 is a diagram showing a modification of the frame format of FIG. A frame format 2b shown in FIG. 13 is obtained by adding a guard section 101 to the frame 2a shown in FIG. Like the guard interval 22, the guard interval 101 does not contribute to data transmission, and therefore may be any signal, a copy of a data portion, a random sequence, or '0' (no transmission). The guard interval 101 is added immediately before an arbitrary guard interval 92, and the number of guard intervals in the frame may be any number greater than or equal to one.

When using the frame format of FIG. 13, the directivity control units 16, 44, 52, 72, 81 and the antenna selection units 35, 65 are replaced with an arbitrary guard in the frame 2 b instead of the guard section 22 in the frame 2. In the section 101 and the guard interval 92, the radiation pattern of the directional variable antenna is changed or the directional fixed antenna used for transmission / reception is changed.

Even with the configuration as described above, it is possible to obtain an effect that deterioration of reception performance can be suppressed when the radiation pattern of the directional antenna is changed or when the directional antenna is changed. In addition, since the guard interval is inserted immediately before the guard interval, the number of effective samples in the guard interval is increased as compared with the frame format of FIG. 12, so that an effect of improving resistance to delayed waves can be obtained. . Further, since the time length that is a candidate for changing the directivity is increased as compared with the frame format of FIG. 12, it is possible to relax the detection accuracy of the guard interval and obtain an effect of reducing the circuit scale. it can.

FIG. 14 is a diagram showing a modified example different from FIGS. 12 and 13 of the frame format of the first to sixth embodiments. The frame format 2c shown in FIG. 14 is obtained by adding a synchronization word (SyncWord) 111 to the front of the frame 2 shown in FIG. Other components are the same as those provided in the frame 2.

The synchronization word 111 is a signal for detecting the head of the frame 2c in the receiving device, and is a signal known in the receiving device, a signal in which the same signal is repeated in time series, null (no transmission), or the like. Any signal may be used as long as it can detect the frame head position.

When the frame format of FIG. 14 is used, the synchronization units 53, 73, and 82 first detect the head position of the frame 2c from the synchronization word 111, and specify the position of the guard section 22 from the head position of the frame 2c.

Even with the configuration as described above, it is possible to obtain an effect that deterioration of reception performance can be suppressed when the radiation pattern of the directional antenna is changed or when the directional antenna is changed.

FIG. 15 is a diagram showing a modification of the frame format of FIG. FIG. 16 is a diagram showing a modification of the frame format of FIG. The frame format 2d shown in FIG. 15 is obtained by adding a sync word 111 in front of the frame 2a shown in FIG. 12, and the frame format 2e shown in FIG. 16 is the frame format shown in FIG. A synchronization word (SyncWord) 111 is added in front of 2b.

When using the frame format of FIG. 15 and FIG. 16, as in the case of using the frame format of FIG. 14, the synchronization units 53, 73 and 82 first detect the head position of the frame 2 d or 2 e from the synchronization word 111, The positions of the guard interval 92 and the guard section 101 are specified from the head position of the frame 2d or 2e.

Even with the configuration as described above, it is possible to obtain an effect that deterioration of reception performance can be suppressed when the radiation pattern of the directional antenna is changed or when the directional antenna is changed.

As described above, the present invention is useful for improving the reception performance of a transmission device and a reception device having an antenna with a sharp directivity, and particularly in an environment where fading fluctuation is moderate, It is suitable for a communication device, a transmission device, and a reception device capable of suppressing deterioration in reception performance by control and antenna selection.

1, 1a, 1b Transmitting device 11 Encoding unit 12 Interleaving unit 13, 41 Modulating unit 14, 42 Guard interval inserting unit 15, 43, 51, 71 Directivity variable antenna 16, 44, 52, 72, 81 Directivity control unit 17, 36, 45 Transmission control unit 2, 2a, 2b, 2c, 2d, 2e Frame 21, 23, 93 Data 22, 101 Guard section 31 Selector 32, 33, 34, 61, 62, 63, 64 Directional fixed antenna 35, 65 Antenna selection unit 5, 5a, 5b, 5c Receiver 53, 73, 82 Synchronization unit 54, 74 Demodulation unit 55 Deinterleaving unit 56 Decoding unit 66 Selective combining unit 91 OFDM symbol 92 Guard interval 111 Synchronization word

Claims (9)

Directional variable antenna that can change the radiation pattern,
A guard interval insertion unit that inserts a guard interval that does not contribute to demodulation to the frame;
In the guard section inserted by the guard section insertion unit, a directivity control unit that instructs the directivity variable antenna to change a radiation pattern;
A transmission device comprising: Multiple antennas,
A selector for selecting an antenna for transmitting a signal from the plurality of antennas;
A guard interval insertion unit that inserts a guard interval that does not contribute to demodulation to the frame;
A directivity control unit that instructs the selector to change the antenna in the guard section inserted by the guard section insertion unit;
A transmission device comprising: The transmission apparatus according to claim 1, wherein a 0 signal is inserted in the guard interval. 4. The transmission apparatus according to claim 1, wherein the transmission system employs OFDM or SC-FDMA block transmission. The transmission apparatus according to claim 4, wherein the guard interval is a guard interval in block transmission. The transmission apparatus according to claim 5, wherein a guard interval is provided in the frame in addition to the guard interval. 7. The transmission apparatus according to claim 1, wherein a synchronization word for frame synchronization is added to the head of the frame. Directional variable antenna,
A synchronization unit for detecting a guard interval that does not contribute to demodulation of a frame from a received signal received by the directivity variable antenna;
A directivity control unit that instructs the variable directivity antenna to change a radiation pattern in the guard interval detected by the synchronization unit;
A receiving apparatus comprising: Multiple antennas,
A synchronization unit that detects a guard interval that does not contribute to demodulation of a frame from a reception signal received by any one of the plurality of antennas;
An antenna selection unit that changes antennas for receiving signals from the plurality of antennas in the guard interval detected by the synchronization unit;
A receiving apparatus comprising:

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