WO2014147944A1

WO2014147944A1 - Transmission device, reception device, and transmission/reception device

Info

Publication number: WO2014147944A1
Application number: PCT/JP2014/000648
Authority: WO
Inventors: 薫塚本; 加藤　泰典; 彰浩岡崎
Original assignee: 三菱電機株式会社
Priority date: 2013-03-19
Filing date: 2014-02-07
Publication date: 2014-09-25
Also published as: JP2016106443A

Abstract

A transmission device characterized by the provision of the following: a variable-directivity antenna, the radiation pattern of which can be changed; a guard-interval insertion unit that inserts, into frames, guard intervals that do not contribute to data transmission; and a control unit that, on the basis of information on the positions at which the guard intervals are inserted, instructs the variable-directivity antenna to change the radiation pattern thereof during the guard intervals.

Description

Transmission device, reception device, and transmission / reception device

The present invention relates to a transmission apparatus, a reception apparatus, and a transmission / 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 having a sharp directivity is used, fading fluctuation becomes slow in time (slow fading), and the received signal power may be lowered for a long time. If the received power reduction time is longer than the interleave length (frame length), it becomes difficult to randomize errors by interleaving, and the effect of a powerful error correction code such as a convolutional code or a turbo code that is a random error correction code cannot be obtained. Reception performance is degraded.

To deal with this problem, Patent Document 1 changes the directivity of the mobile station antenna with a time length shorter than the interleave length to give a fading fluctuation in the frame, thereby improving the effect of the error correction code. It is disclosed.

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 suppress deterioration in reception performance even when directivity is changed.

In order to solve the above-described problems and achieve the object, a transmission apparatus according to 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 data transmission, and a guard. A control unit is provided that instructs the variable directivity antenna to change the radiation pattern in the guard section based on the position information of the section insertion.

Further, the transmission apparatus of the present invention includes a plurality of antennas, a selector that selects an antenna from the plurality of antennas, a guard interval insertion unit that inserts a guard interval that does not contribute to data transmission in a frame, and a selector based on position information of guard interval insertion Is provided with a control unit for instructing to change the antenna in the guard section.

In addition, the receiving apparatus of the present invention detects a guard section that does not contribute to frame data transmission from a received signal received by a directional variable antenna, a directional variable antenna, and detects a directional variable antenna by a synchronizing section. And a control unit that instructs to change the radiation pattern in the guard section.

The receiving apparatus of the present invention also detects a guard interval that does not contribute to frame data transmission from a plurality of antennas, a selection combining unit that selects an antenna from a plurality of antennas, and a received signal received by any one of the plurality of antennas. In the synchronizing unit and the guard section, the control unit is configured to instruct the selective combining unit to change the antenna in the guard section.

In addition, according to the present invention, a transmission / reception apparatus that transmits and receives data using time division duplex that distinguishes between transmission and reception by time-division of the same frequency includes a variable directivity antenna that can change a radiation pattern, uplink and downlink In a gap section provided to prevent a link collision, a control unit that instructs the variable directivity antenna to change the radiation pattern is provided.

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.

3 is a diagram illustrating a configuration example of a transmission apparatus according to Embodiment 1. FIG. 6 is a diagram showing an example of a frame configuration in Embodiments 1 to 6. FIG. 6 is a diagram illustrating a modification of the transmission apparatus according to Embodiment 1. FIG. 6 is a diagram illustrating a configuration example of a transmission apparatus according to Embodiment 2. FIG. FIG. 10 is a diagram illustrating a modification of the transmission apparatus according to the second embodiment. FIG. 11 is a diagram illustrating a configuration example of a transmission device according to a third embodiment. FIG. 10 is a diagram illustrating a modification of the transmission device according to the third embodiment. FIG. 11 is a diagram illustrating a configuration example of a receiving device according to a fourth embodiment. FIG. 10 is a diagram illustrating a configuration example of a receiving device according to a fifth embodiment. FIG. 20 is a diagram illustrating a configuration example of a receiving device according to a sixth embodiment. FIG. 38 is a diagram illustrating a modification of the reception device in the sixth embodiment. FIG. 10 is a diagram showing a modification of the frame configuration of the first to sixth embodiments. FIG. 10 is a diagram showing a modification of the frame configuration of the first to sixth embodiments. FIG. 10 is a diagram showing a modification of the frame configuration of the first to sixth embodiments. FIG. 10 is a diagram showing a modification of the frame configuration of the first to sixth embodiments. FIG. 10 is a diagram showing a modification of the frame configuration of the first to sixth embodiments. FIG. 10 is a diagram showing a modification of the frame configuration of the first to sixth embodiments. FIG. 11 is a diagram showing a modification of the transmission device and the reception device in 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 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, 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 serving as a control unit 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. The transmitter 1a shown in FIG. 4 adds a selector 31 to the transmitter 1 described in the first embodiment, and replaces the directivity control unit 16 with an antenna selection unit 35 serving as a control unit. Are replaced by directional fixed antennas 32 to 34, respectively.

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 arranged so that the radiation patterns are in different directions. Therefore, unlike the directivity variable antenna 15 in the first embodiment, the radiation patterns need not be changeable. However, it is assumed that the directivity fixed antennas 32 to 34 have sharp directivities 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. Further, the directivity fixed antennas 32 to 34 not designated by the antenna selector 35 are set to 0 output (no output signal). Directional fixed antennas 32 to 34 transmit the output signal of 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 predetermined modulation processing on the output signal of the interleaving unit 12 to generate a first modulation signal and a second modulation signal that are modulation signals for two antennas (directivity variable antennas 15 and 43). To do. 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.

Thus, in a transmitter having a plurality of directional variable antennas, each directional variable antenna independently changes its own radiation pattern in the guard section 22 that does not contribute to data transmission, thereby changing the radiation pattern. Thus, it is possible to remove the influence of the discontinuity of the transmission signal that accompanies the data portion on the data portion, thereby suppressing the deterioration of the reception performance when changing the radiation pattern.

Although the number of directional variable antennas has been described as two, the number of antennas is not limited to this, and the same effect can be obtained even when the number of directional 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 the first to third embodiments, the transmission device 1 including a directional antenna has been described. In the present embodiment, a reception device 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 serving as a control unit 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 device 5a shown in FIG. 9 adds a selection / synthesis unit 66 to the receiving device 5 shown 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 directivity fixed antennas 61 to 64 need not be able to change the radiation pattern. However, it is assumed that the directivity fixed antennas 61 to 64 have a sharp directivity similar to the directivity variable antenna 51.

Directional fixed antennas 61 to 64 receive signals transmitted from a counter device (not shown). Each reception signal received by the directional fixed antennas 61 to 64 is input to the selection / synthesis 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 serving as a control unit, and outputs the selected signal to the synchronization unit 53 To do. As a combining method in the selection combining unit 66, all the reception signals from the directivity 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 selecting 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 showing a modification of the frame format in 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 for 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, 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, although the number of OFDM symbols in the frame 2a is four, 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).

In addition, the OFDM symbol 91 in FIG. 12 may be of any format that uses a guard interval, such as a SC-FDMA (Single Carrier-Frequency 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 changing the radiation pattern of the variable directivity antenna or changing the fixed directivity antenna. 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 variable antenna is changed or when the directional fixed 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 variable antenna is changed or when the directional fixed 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.

FIG. 17 is a diagram showing a modification of the frame format in the first to sixth embodiments. The frame format 2 f shown in FIG. 17 is a frame in a TDD (Time Division Division Duplex: time division duplex that distinguishes transmission from reception by time division of the same frequency) using the same frequency in the uplink and downlink. This is a format in which the

data

21 and 23 are replaced with the uplink signal 94 and the downlink signal 95 for the frame 2 shown in FIG. The guard section 22 corresponds to a gap section provided for preventing collision between the uplink and the downlink.

When the frame format of FIG. 17 is used, the transmission-side guard

interval insertion units

14 and 42 in Embodiments 1 to 6 are not necessary. Further, it is not necessary to notify the guard section insertion position information from the receiving-

side synchronization units

53, 73, 82 to the

directivity control units

52, 72, 81 and the antenna selection unit 65 in the first to sixth embodiments.

Further, in the TDD scheme, since the transmission device and the reception device grasp the timing of the gap section, the

directivity control units

16, 44, 52, 72, and 81 and the

antenna selection units

35 and 65 are the gap section portions. The radiation pattern of the directivity variable antenna is changed or the directivity fixed antenna used for transmission / reception is changed.

FIG. 18 is a diagram illustrating a modification of the transmission device and the reception device in the TDD scheme. In FIG. 18, the transmission device and the reception device are collectively referred to as a communication device (transmission / reception device) 1c. In the communication device 1c, the directivity variable antenna 96 transmits and receives radio signals to and from the opposite device, and the received power measuring unit 98 measures the received power of the received signal received by the directivity variable antenna 96 and sends it to the directivity control unit 97. Output. The directivity control unit 97 controls the directivity of the directivity variable antenna 96. The directivity control unit 97 is directed in the gap section when the reception power input from the reception power measurement section 98 is equal to or less than a certain value in the reception period (uplink section 94 when the communication device 1c is a base station). The radiation pattern of the variable variable antenna 96 is changed. In the TDD scheme, since the transmitter and the receiver know the timing of the gap section, the directivity control unit 97 knows the timing of the gap section in advance using this timing information. However, the present invention is not limited to this. Absent. For example, the directivity control unit 97 may obtain gap section information from the synchronization unit 53.

As described above, with the configuration in which the radiation pattern of the directional variable antenna is changed only when the received power is small, the propagation path characteristic is deteriorated in the TDD scheme in which the propagation path characteristic is the same in the uplink and the downlink. Only in the case can the radiation pattern of the directional variable antenna be changed. Therefore, when reception characteristics deteriorate in the uplink (or downlink), the possibility of improving the reception characteristics of the downlink (or uplink) can be increased.
In addition, it is possible to suppress degradation of reception characteristics due to unnecessary radiation pattern changes.

Further, even when the frame format of FIG. 17 is used in the TDD scheme, the transmission-side guard

interval insertion units

14 and 42 in Embodiments 1 to 6 may be provided. Also, the guard section insertion position information may be notified from the receiving-

side synchronization units

53, 73, and 82 to the

directivity control units

52, 72, and 81 and the antenna selection unit 65 in the first to sixth embodiments. That is, the frame format of the uplink signal 94 and the downlink signal 95 may be any of FIG. 2 and FIGS.

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.

DESCRIPTION OF

SYMBOLS

1, 1a, 1b: Transmission apparatus, 1c: Transmission / reception apparatus, 11: Encoding part, 12: Interleaving part, 13, 41: Modulation part, 14, 42: Guard section insertion part, 15, 43, 51, 71, 96 : Directivity variable antenna, 16, 44, 52, 72, 81, 97: Directivity control unit, 17, 36, 45: Transmission control unit, 2, 2a, 2b, 2c, 2d, 2e, 2f: Frame, 21 , 23, 93, 94, 95: Data, 22, 101: Guard section, 31: Selector, 32, 33, 34, 61, 62, 63, 64: Directivity fixed antenna, 35, 65: Antenna selection unit, 5 5a, 5b, 5c: receiving device, 53, 73, 82: synchronization unit, 54, 74: demodulation unit, 55: deinterleaving unit, 56: decoding unit, 66: selection combining unit, 91: OFDM symbol, 92: Guard interval, 1 11: Sync word, 98: Received power measurement unit

Claims

Directional variable antenna that can change the radiation pattern,
A guard interval insertion unit that inserts a guard interval that does not contribute to data transmission in the frame;
Based on position information of guard section insertion, a control unit that instructs the directivity variable antenna to change a radiation pattern in the guard section,
A transmission device comprising:
Multiple antennas,
A selector for selecting an antenna from the plurality of antennas;
A guard interval insertion unit that inserts a guard interval that does not contribute to data transmission in the frame;
A control unit that instructs the selector to change the antenna in the guard section based on position information of the guard section insertion;
A transmission device comprising:
The transmission apparatus according to claim 1, wherein the position information of the guard interval insertion is obtained from the guard interval insertion unit.
4. The transmission apparatus according to claim 1, wherein a 0 signal is inserted in the guard interval.
5. The transmission apparatus according to claim 1, wherein the transmission system employs OFDM or SC-FDMA block transmission.
The transmission apparatus according to claim 5, wherein the guard interval is a guard interval in block transmission.
The transmission apparatus according to claim 6, wherein a guard interval is provided in the frame in addition to the guard interval.
8. 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 data transmission of a frame from a received signal received by the directivity variable antenna;
A control unit that instructs the variable directivity antenna to change a radiation pattern in the guard section detected by the synchronization unit;
A receiving apparatus comprising:
Multiple antennas,
A selective combining unit for selecting an antenna from the plurality of antennas;
A synchronization unit that detects a guard interval that does not contribute to data transmission of a frame from a reception signal received by any one of the antennas;
In the guard section, a control unit that instructs the selection combining unit to change the antenna in the guard section,
A receiving apparatus comprising:
In a transmission / reception device that transmits and receives data using time division duplex to distinguish between transmission and reception by time division of the same frequency,
Directional variable antenna that can change the radiation pattern,
A control unit for instructing the directional variable antenna to change a radiation pattern in a gap section provided to prevent an uplink and downlink collision;
A transmission / reception device comprising: