WO2020194423A1

WO2020194423A1 - Radio communication device

Info

Publication number: WO2020194423A1
Application number: PCT/JP2019/012378
Authority: WO
Inventors: 仲田　樹広; 武鎗　良治
Original assignee: 株式会社日立国際電気
Priority date: 2019-03-25
Filing date: 2019-03-25
Publication date: 2020-10-01
Also published as: JP7140907B2; JPWO2020194423A1

Abstract

Provided is a radio communication device capable of efficiently transmitting a plurality of different types of data at the same frequency and time.　The radio communication device is provided with: an antenna unit 19 which outputs an upper layer (UL) beam and a lower layer (LL) beam into space at the same frequency and time; an upper IL control unit 13 and a lower IL control unit 14 which respectively adjust the power ratio of the UL beam and the LL beam; and an upper-layer amplitude/phase control unit 15 and a lower-layer amplitude/phase control unit 16 which respectively control the widths of the UL and LL beams. The upper-layer amplitude/phase control unit 15 and the lower-layer amplitude/phase control unit 16 perform control to reduce the width of the UL beam and increase the width of the LL beam. In addition, the upper IL control unit 13 and the lower IL control unit 14 perform adjustment such that radiated power of the UL beam becomes greater than the radiated power of the LL beam and the difference between the radiated power of the two is greater than or equal to a predetermined power difference in the transmission direction of the UL beam and the range of the width of the UL beam.

Description

Wireless communication device

The present invention relates to a wireless communication device that transmits a plurality of data in a layer division multiplexing system.

In the 5th generation communication, the communication method that uses a wide bandwidth to increase the throughput has become the mainstream. On the other hand, the current carrier frequency band is tight, and it is difficult to secure a wide frequency band. Therefore, it has been proposed to use a submillimeter wave or a millimeter wave frequency band in which a wide frequency band can be easily secured. Since free space loss is large in such a high frequency band, "Massive MIMO" that forms a pencil beam with a large antenna gain by controlling their phases using multiple antennas in order to expand the communication area. Or, "Phased Array" technology is often used.

In the field of broadcasting, ATSC (Advanced Television Systems Committee standards) 3.0, which is the next-generation terrestrial digital broadcasting standard in the United States, provides two different services in the upper layer (UL) and the lower layer (Lower Layer: UL). A method of allocating to LL) and multiplexing UL and LL with different power ratios for transmission is adopted. This technique is referred to as Layered Division Multiplexing (LDM) (see Non-Patent Documents 1 and 2). Further, in cellular communication, a similar technique is used as a method called NOMA (Non Orthogonal Multiplexing Access).

Hereinafter, a schematic configuration of a conventional LDM transmitting device and an LDM receiving device will be described.
FIG. 12 is a diagram showing an example of a functional block of a conventional LDM transmitter. As shown in FIG. 12, the conventional LDM transmission device includes an UL data processing unit 100, an LL data processing unit 101, a synthesis unit 124, and an OFDM (Orthogonal Frequency Division Multiplexing) modulation unit 125. , The transmitting antenna 126 is provided.

The UL data processing unit 100 processes UL data, and includes a UL error correction coding unit 121U, a UL carrier modulation unit 122U, and a power adjustment unit 123U. Similarly, the LL data processing unit 101 that processes LL data includes an LL error correction coding unit 121L, an LL carrier modulation unit 122L, and a power adjustment unit 123L.

The operation of the conventional LDM transmitter will be described.
The UL information bit is input to the UL error correction coding unit 121U of the UL data processing unit 100, and the UL error correction coding unit 121U performs predetermined error correction coding. After that, the UL carrier modulation unit 122U uses a modulation method that maps to the IQ plane by quadrature amplitude modulation (QAM), PSK (Phase Shift Keying), or unequal interval quadrature modulation (Non Uniform QAM). It is modulated by the digital modulation method. Then, the transmission power of the modulated UL signal is adjusted by the power adjusting unit 123U so that the UL and LL have a predetermined power ratio, and the modulated UL signal is input to the combining unit 124.

In the LL that transmits information different from the UL, information bits are input to the LL data processing unit 101, error correction coding is performed by the LL error correction coding unit 121L, and carrier modulation is performed by the LL carrier modulation unit 122L. Then, the transmission power is adjusted by the power adjustment unit 123L and input to the synthesis unit 124.

The error correction coding performed by the UL error correction coding unit 121U and the LL error correction coding unit 121L may be the same error correction coding method or different methods. The carrier modulation method in the UL carrier modulation unit 122U and the LL carrier modulation unit 122L is, for example, modulation of UL by 64QAM and LL by QPSK (Quadrature Phase Shift Keying), or modulation of UL by QPSK and LL by 64QAM. In addition, the transmission power is generally UL transmission power and LL transmission power, that is, UL and LL radiated power (effective radiated power or effective isotropic radiated power) in order to facilitate demodulation processing on the receiving side. It is desirable to make a difference in.

Then, the UL and LL signals are combined by the synthesis unit 124, the combined signal is OFDM-modulated by the OFDM modulation unit 125, and the combined signal is output as a transmission signal from the transmission antenna 126. In this way, the operation of the conventional LDM transmitter is performed.

Next, the configuration of the conventional LDM receiving device will be described with reference to FIG. FIG. 13 is a diagram showing an example of a functional block of a conventional LDM receiving device. As shown in FIG. 13, the conventional LDM receiving device includes a receiving antenna 130, an OFDM demodulation unit 131, a UL carrier demodulation unit 132, a UL error correction decoding unit 133, a replica generation unit 134, and a removal processing unit. It includes 135, an LL carrier demodulation unit 136, and an LL error correction / decoding unit 137.

The operation of the conventional LDM receiving device will be described.
In the conventional LDM receiving device, the transmitted signal multiplexed and transmitted is received by the receiving antenna 130 of the receiving device, and the OFDM demodulation unit 131 performs FFT (Fast Fourier Transform) processing, transmission path estimation, and other OFDM. The demodulation process is performed, and the process is branched into the UL carrier demodulation section 132 and the removal processing section 135. For one of the branched signals, the UL carrier demodulation unit 132 performs carrier demodulation corresponding to the carrier modulation applied to the UL data on the transmitting side.

The carrier-demodulated UL signal is subjected to error correction and decoding corresponding to the UL error correction coding unit 121U on the LDM transmission device side by the UL error correction and decoding unit 133, and the UL decoding bit is output. At the same time, the UL decoding bit decoded by the UL error correction decoding unit 133 is input to the replica generation unit 134, and carrier modulation is performed again by the modulation method used by the UL carrier modulation unit 122U on the LDM transmitter side. Then, a replica of the UL reception signal (UL replica signal) is generated by using the propagation path estimation result and the like.

Then, in the removal processing unit 135, the UL replica signal is removed from the multiplexed signal from the OFDM demodulation unit 131, and the LL signal, which is the LL reception signal, is taken out. After that, with respect to the LL signal, the LL carrier demodulation unit 136 performs carrier demodulation of the LL signal in consideration of the power ratio of UL and LL in the

power adjustment units

123U and 123L on the LDM transmitter side. The signal from the LL carrier demodulation unit 136 is input to the LL error correction / decoding unit 137, error correction / decoding corresponding to the LL error correction code unit 121L on the LDM transmission device side is performed, and the LL decoding bit is output. In this way, the operation in the receiving device is performed.

The signal from the OFDM demodulation unit 131 is a state in which the UL signal and the LL signal are combined, but assuming that error correction decoding and replica generation are performed accurately, the output of the replica generation unit 134 is pure UL. The UL signal, which is the received signal, will be reproduced. Therefore, the LL signal can be extracted by subtracting the UL replica signal from the multiplexed OFDM demodulated signal.

For example, in cellular, when a base station manages a plurality of terminal stations existing in its own sector, the data signal and the control signal are often transmitted using different lines such as different frequencies, and the frequency utilization efficiency is poor. There was a problem. Further, when a plurality of frequencies are used, an RF (Radio Frequency) circuit corresponding to each frequency is required, which causes an increase in the scale of the device.

The present invention has been made in view of the above-mentioned conventional circumstances, and provides a wireless communication device capable of efficiently transmitting a plurality of different types of data at the same frequency and time. With the goal.

In order to achieve the above object, in the present invention, the wireless communication device is configured as follows.
That is, in a wireless communication device that transmits a plurality of data in a time division multiplexing system, a first beam that transmits the first data and a second beam that transmits the second data that is different from the first data. An antenna that outputs to space at the same frequency and time, a power ratio adjusting unit that adjusts the power ratio of the first beam and the second beam, and a beam width that controls the width of the first beam and the second beam. A control unit is provided, and the beam width control unit is characterized in that the width of the first beam and the width of the second beam are controlled to be different from each other.

As described above, the wireless communication device according to the present invention has a configuration in which the first data and the second data of a different type from the first data are transmitted by a layer division multiplexing method using beams having different widths. ing. This makes it possible to efficiently transmit a plurality of different types of data at the same frequency and time.

As a configuration example, when the wireless communication device according to the present invention transmits data used for controlling the transmission of the first data as the second data, the beam width control unit uses the first beam. The width of the second beam may be narrowed and the width of the second beam may be widened.

In this case, in the power ratio adjusting unit, the radiated power of the first beam is larger than the radiated power of the second beam in the transmission direction of the first beam and the width range of the first beam. It may be adjusted so as to be equal to or more than a predetermined power difference. Alternatively, the power ratio adjusting unit determines that the radiated power of the second beam is larger than the radiated power of the first beam in the transmission direction of the first beam and the width of the first beam. It may be adjusted so as to be equal to or greater than the power difference of. In addition, the second data may include the position information of the wireless communication device.

Further, the beam width control unit may be configured to digitally control the widths of the first beam and the second beam. Further, the beam width control unit may be configured to control the widths of the first beam and the second beam by an analog method. Further, the antenna radiates a reflecting mirror, a first radiator that radiates a radio wave of the first data to the reflecting mirror to generate the first beam, and a radio wave of the second data to the reflecting mirror. It has a second radiator that generates the second beam, and the beam width control unit adjusts the position of the first radiator and the position of the second radiator with respect to the reflector. , The width of the first beam and the width of the second beam may be controlled.

Further, in the wireless communication device according to the present invention, the pilot signal used for demodulating the first data and the pilot signal used for demodulating the second data are orthogonal to each other in the region of time, frequency, or code. It may be configured to be arranged in a relationship and transmitted.

According to the present invention, it is possible to provide a wireless communication device capable of efficiently transmitting a plurality of different types of data at the same frequency and time.

It is a figure which shows an example of the functional block of the wireless communication apparatus which concerns on 1st Example. It is a figure which shows the directivity gain when the beam direction is in front of an antenna. It is a figure which shows the directivity gain when the beam direction is tilted from the front of an antenna. It is a figure explaining the use example of the wireless communication apparatus which concerns on 1st Example. It is a figure which shows the example of the beam shape of UL and LL in 1st Example. It is a figure which shows the example of the constellation of the receiving side in the direction which the antenna gain of UL is maximum. It is a figure which shows the example of the constellation of the receiving side in the direction which the antenna gain of UL is small. It is a figure explaining another use example of the wireless communication apparatus which concerns on 1st Example. It is a figure which shows the example of the beam shape of UL and LL in the 2nd Example. It is a figure explaining a general parabola antenna. It is a figure explaining the parabolic antenna in the 3rd Example. It is a figure explaining the arrangement of the pilot signal in 4th Example. It is a figure which shows an example of the functional block of the conventional LDM transmission apparatus. It is a figure which shows an example of the functional block of the conventional LDM receiver.

A wireless communication device according to an embodiment of the present invention will be described with reference to the drawings.
(First Example)
FIG. 1 shows an example of a functional block of the wireless communication device according to the first embodiment of the present invention. The wireless communication device of this example includes an upper layer modulation unit 11, a lower layer modulation unit 12, an upper IL (Injection Level) control unit 13, a lower IL control unit 14, and an upper layer amplitude / phase control unit 15. It includes a lower layer amplitude / phase control unit 16, a synthesis unit 17, an RF conversion unit 18, and an antenna unit 19.

Information A and information B are supplied to the wireless communication device of this example from the outside. Information A and information B are data having different contents, and details will be described later, but their transmission rates are often different. Information A is input to the upper layer modulation unit 11, and information B is input to the lower layer modulation unit 12.
The upper layer modulation unit 11 performs communication path coding and digital modulation processing on the information A. Similarly, the lower layer modulation unit 12 performs communication path coding and digital modulation processing on the information B.

In communication path coding, codes such as convolutional code, turbo code, and LDPC (Low Density Parity Check) are often used. Alternatively, concatenated coding is often used in which these codes are used as internal codes and codes such as RS (Reed-Solomon) code and BCH (Bose-Chaudhuri-Hocquenghem) code are used as external codes. In the present invention, since it does not depend on these codes, any code may be adopted.

For digital modulation processing, a single carrier modulation method or OFDM is often used. In addition, FBMC (Filter Bank Multi-Carrier), GFDM (Generalized Frequency Division Multiplexing), etc. are also under study as the fifth generation communication method. Since the present invention does not largely depend on these modulation methods, the following description will be made using OFDM, which has been the mainstream in recent years. In the OFDM method, after performing primary modulation such as QPSK or 16QAM, digital modulation is performed by secondary modulation in which these plurality of subcarriers are multiplexed while being orthogonal to each other on the frequency axis.

In this way, in the upper layer modulation unit 11, the information A is subjected to communication path coding, digital modulation processing, and the like, and a modulation signal is generated. Similarly, in the lower layer modulation unit 12, the information B is subjected to communication path coding and digital modulation processing, and a modulation signal is generated. The coding rate of the communication path coding and the number of modulation multi-values of the digital modulation in the upper layer modulation unit 11 and the lower layer modulation unit 12 will be described later.

The modulation signal of information A output from the upper layer modulation unit 11 is transmitted to the upper layer amplitude / phase control unit 15 after the coefficient α is multiplied by the upper IL control unit 13. The upper layer amplitude / phase control unit 15 performs a process of forming a radiation beam of information A.
Similarly, the modulation signal of the information B output by the lower layer modulation unit 12 is transmitted to the lower layer amplitude / phase control unit 16 after the coefficient β is multiplied by the lower IL control unit 14. The lower layer amplitude / phase control unit 16 performs a process of forming a radiation beam of information B.
In the first embodiment, the coefficients α and β used in the upper IL control unit 13 and the lower IL control unit 14 will be described with α = β = 0.5. That is, a case where the total transmission power of UL and the total transmission power of LL are equalized will be described.

The upper layer amplitude / phase control unit 15, the modulated signals from the higher hierarchical modulation unit 11, N types (N is a natural number, consistent with the number of antenna elements having the antenna unit 19) the amplitude A _n of ( n is an antenna number, and outputs the result of variably controlling 1 ≦ n ≦ N) and the phase θ _n . A radiation beam is formed by this control, and the shape of the beam also depends on the arrangement of the antenna elements of the antenna unit 19. For example, when the antenna elements are arranged in a row at equal intervals, if each phase (θ ₁ to θ _{6 in} FIG. 1) is controlled to be equal, the signal transmitted from each antenna is transmitted to the antenna row. In-phase synthesis is performed in the front direction, and a high antenna gain can be obtained. At this time, when forming a sharp pencil beam, it is desirable that the amplitudes of the upper layer amplitude / phase control unit 15 (A ₁ to A _{6 in} FIG. 1) are the same.

FIG. 2 shows the directivity gain when the beam direction is in front of the antenna. According to the figure, a high antenna gain is obtained in the front direction, but the antenna gain is low in directions other than the front. This is because the phases at the time of spatial composition are different in directions other than the front surface, and they may be canceled by opposite phases.

FIG. 3 shows the directivity gain when the beam direction is tilted from the front of the antenna. In this way, when it is desired to form a beam in a direction other than the front surface, the phase of the upper layer amplitude / phase control unit 15 (θ ₁ to θ _{6 in} FIG. 1) may be controlled so that in-phase synthesis is performed in a desired direction. ..
As described above, by controlling the phase θ _n of the upper layer amplitude / phase control unit 15, energy can be concentrated in a desired direction to perform energy-efficient wireless transmission.

Here, the description of the configuration of the wireless communication device will be separated, and the problem to be solved in this embodiment will be described.
FIG. 4 shows an example in which the wireless communication device shown in FIG. 1 is mounted on the base station 21 and the base station 21 and the three terminal stations 22 to 24 perform data communication. When the base station 21 wants to perform data communication with the terminal station 22 (terminal X), the base station 21 may form the beam described above in that direction. Similarly, if you want to perform data communication with another terminal station, you can form a beam in that direction. Although it depends on the beam shape, in general, when a sharp pencil beam having a high antenna gain is formed, the antenna gain is lowered at a terminal station other than the terminal station to be communicated with, so that data communication cannot be performed.

Here, when the base station 21 puts all of these three terminal stations 22 to 24 under control control, it is desirable to notify all the terminal stations of the control information. In cellular communication, when the User-Plane that transmits the data signal and the Control-Plane that transmits the control signal have different frequencies, and the control signal is notified using a communication line different from the data signal. There are many.

For example, as an example of communication between a data signal and a control signal, when the base station 21 communicates with all of the terminal stations 22 to 24, it follows some scheduling rules (the scheduling method is not specified) to each terminal station. Consider performing data communication while forming a directed beam in a time-division manner. At this time, during the period of data communication with a certain terminal station, control information such as schedule information is notified to other terminal stations, and timing synchronization is performed with terminal stations not subject to data communication. It is possible to communicate more efficiently if you are there.

In the first embodiment, by providing a layer division multiplexing wireless communication device that forms a beam so that a data signal for a specific terminal station and a control signal for a plurality of terminal stations can be communicated at the same frequency as described above. , Improve frequency utilization efficiency and simplify the system.
Hereinafter, a method for realizing a higher layer for data communication while forming a beam and a lower layer for broadcasting control signals to a plurality of terminal stations at the same frequency, which is the main object of the present invention, will be described.

As described above, the data signal is transmitted while forming a beam by using the upper layer modulation unit 11 and the upper layer amplitude / phase control unit 15.
On the other hand, the control signal is transmitted while forming a beam by using the lower layer modulation unit 12 and the lower layer amplitude / phase control unit 16. When the same control information is transmitted to all the terminal stations 22 to 24 of FIG. 4, it is a broadcast type communication.

In general, since the transmission rate of the control signal is lower than that of the data signal, the coding rate of the lower layer modulation unit 12 is low, and the number of modulation multi-values is also low, so that even if the reception power is low. It becomes possible to demodulate. For example, the coding rate is set to 1/3, and BPSK (Binary Phase Shift Keying) is used as the modulation method. Alternatively, when the stability is further improved, the diversity effect can be obtained by transmitting the same data a plurality of times, and the quality of the received signal can be improved.
On the contrary, the data signal is often required to have high throughput, and a high-order multi-level number such as 64QAM or 256QAM is used as the modulation multi-level number, so that the received power (high reception S / N) is correspondingly high. I need.

The modulation signal generated by the lower layer modulation unit 12 is transmitted to the lower layer amplitude / phase control unit 16. The lower layer amplitude / phase control unit 16 forms a broad radiation beam so as to target a plurality of terminal stations. When forming a broad beam, it is better to provide a difference in the amplitudes (B ₁ to B ₆ ) of the lower layer amplitude / phase control unit 16. For example, by setting the amplitude of only B ₃ to √6 and setting the other B ₁ , B ₂ , B ₄ , B ₅ , and B ₆ to 0, the normalized power of LL becomes the same value as UL, and the beam is the most. Can be formed broad. Further, the beam shape formed by the lower layer amplitude / phase control unit 16 does not necessarily have to be broad, and it is possible to narrow the beam width and variably control the beam direction as in the upper layer.

The signal from the upper layer amplitude / phase control unit 15 and the signal from the lower layer amplitude / phase control unit 16 are combined by the synthesis unit 17. Here, it is desirable that the modulation signal generation timing of the upper layer modulation unit 11 and the modulation signal generation timing of the lower layer modulation unit 12 are the same. When the OFDM signal is used, the same symbol timing is used in the upper layer modulation unit 11 and the lower layer modulation unit 12.
The signal synthesized by the synthesis unit 17 is converted into an RF signal by the RF conversion unit 18 and transmitted from the antenna unit 19.

Since the RF conversion unit 18 and the antenna unit 19 are analog elements, individual differences in characteristics occur. Therefore, if the upper layer amplitude / phase control unit 15 and the lower layer amplitude / phase control unit 16 obtain these individual differences in advance by some method and offset the calibration coefficient for reducing the individual differences. Good. The method for measuring individual differences is not directly related to the present invention and is not described here.

FIG. 5 shows an example of UL and LL beam shapes in the first embodiment. In the figure, the beam width of UL (data signal) shown by the solid line is narrowed, and the beam width of LL (control signal) shown by the dotted line is widened. As described above, in the wireless communication device of the first embodiment, UL and LL are independently beam-formed.

Next, processing on the receiving side (for example, terminal stations 22 to 24 in FIG. 4) will be described.
In the case of OFDM, if the timings of the UL signal and the LL signal are exactly the same, the orthogonality of each subcarrier is maintained for both UL and LL, and the constellation on the receiving side is observed as shown in FIGS. 6A and 6B. Will be done.

FIG. 6A shows an example of the constellation on the receiving side in the direction in which the UL antenna gain is maximum. It is assumed that the UL signal indicated by ◯ is modulated by 16QAM and the LL signal indicated by × is modulated by QPSK. Only the x mark is observed as the constellation, but the UL signal indicated by the ○ mark can be demodulated from the observed received signal. At this time, the LL signal indicated by the cross behaves as noise for the UL signal.

Here, the UL received power to LL received power ratio will be described.
The total transmit power of UL and the total transmit power of LL are set to equal powers, and LL is assumed to be an omnidirectional antenna gain. In this case, in the direction in which the UL antenna gain is maximum, the UL received power is 20 log ₁₀ (N) [dB] larger than the LL received power. Therefore, when the thermal noise generated by the LNA (Low Noise Amplifier) of the receiving unit is sufficiently smaller than the LL receiving power, the required S / N ratio (Signal-to-Noise ratio) is 20 log ₁₀ (N) [dB]. ], It is possible to perform transmission using a multi-valued modulation.

Further, when demodulating the LL signal, as shown in Non-Patent Documents 1 and 2, after demodulating the UL signal, a replica of the UL signal is generated and subtracted from the received signal to extract the LL signal. There are SIC (Successive Interference Canceller) and MLD (Maximum Likelihood Detection) methods that treat UL and LL as one signal and demodulate UL and LL at the same time. By using these methods, the UL signal (information A) and the LL signal (information B) can be reproduced.

FIG. 6B shows an example of the constellation on the receiving side in the direction in which the UL antenna gain is small. The UL signal indicated by a circle is small, and the LL signal indicated by a cross is received with a relatively large value. The figure is an example of a terminal station that does not perform data transmission and receives only a control signal, and the signal marked with x, which is an LL signal, may be demodulated. At this time, the UL signal component (marked with ◯) leaking with respect to the LL signal behaves as noise.

In this way, it is possible to demodulate both the UL signal and the LL signal in the direction in which the UL antenna gain is maximized, and only the LL signal can be demodulated in the other directions. By doing so, even when the base station manages a plurality of terminal stations in the sector as described above, the control signal can be transmitted to all the terminals at the same time.

Next, with reference to FIG. 7, another usage example of the wireless communication device according to the first embodiment will be described. FIG. 7 shows an example in which the wireless communication device shown in FIG. 1 is mounted on a base station 31 and a terminal station 32 (for example, a helicopter), and the base station 31 and the moving terminal station 32 perform two-way communication while tracking a beam. Is shown. The base station 31 and the terminal station 32 communicate with each other using a pencil beam in order to realize high throughput for data signals. At this time, in order to control the beams in the direction of each other, a broad beam is formed in the LL, and a control signal including its own position information acquired by GPS (Global Positioning System) or the like is transmitted. Since the throughput of position information and the like may be low, it can be transmitted by a broad beam having a small antenna gain.

Also, the transmission of location information by LL is effective even when the terminal station does not move. That is, by broadcasting control information including GPS position information from the base station to all terminal stations, each terminal station can accurately grasp the position of the base station, so that the terminal station can move to the base station side. When transmitting data, it is possible to perform beam control that can obtain high transmission efficiency.

As described above, in the wireless communication device according to the first embodiment, the UL beam for transmitting the data signal and the LL beam for transmitting the control signal used for controlling the transmission of the data signal have the same frequency. And the antenna unit 19 that outputs to space in time, the upper IL control unit 13 and lower IL control unit 14 that adjust the power ratio of each beam of UL and LL, and the upper layer that controls the width of each beam of UL and LL. It includes an amplitude / phase control unit 15 and a lower layer amplitude / phase control unit 16. Then, the upper layer amplitude / phase control unit 15 and the lower layer amplitude / phase control unit 16 control to narrow the width of the UL beam and widen the width of the LL beam. Further, by the upper IL control unit 13 and the lower IL control unit 14, the radiant power of the UL beam is larger than the radiated power of the LL beam in the range of the UL beam transmission direction and the UL beam width. It is configured to be adjusted so that the power difference exceeds a predetermined value.

Therefore, the wireless communication device according to the first embodiment can be mounted on a base station, for example, so that the base station transmits control signals to all terminals in the sector, and at the same time, to a specific terminal station. It is possible to transmit a data signal. Further, for example, by transmitting the position information of the wireless communication device as a control signal, it becomes possible to perform beam control that can obtain high transmission efficiency when data is transmitted from the terminal station to the base station side. Further, for example, when one or both of the communication partners move, bidirectional communication can be performed while tracking the beam by notifying each other's position information with a control signal. In this way, it is possible to efficiently transmit a plurality of different types of data at the same frequency and time.

(Second Example)
The wireless communication device according to the second embodiment of the present invention will be described. In the second embodiment, unlike the first embodiment, a case where the first data signal is assigned to the LL and the second data signal different from the first data signal is assigned to the UL will be described. In the beam formation, as in the first embodiment, UL is a sharp pencil beam and LL is a broad beam.

In the second embodiment, a large total transmission power is assigned to the LL signal, and a small total transmission power is assigned to the UL signal. In the first embodiment, both UL and LL have the same transmission power of 0.5 [W], and the total of UL and LL has a transmission power of 1 [W]. In order to facilitate comparison with the first embodiment, the total transmission power of UL and LL will be described as 1 [W] in the second embodiment as well.

Since a large transmission power is allocated to the LL signal, the coefficient β used by the lower IL control unit 14 is set to a value larger than the coefficient α used by the upper IL control unit 13 (that is, β> α). Assuming that the relative power difference between LL and UL is γ [dB], the normalized power is 1, so the values of β and α are represented by the following (Equation 1).

Here, in the second embodiment, since the UL signal is beam-formed as in the first embodiment, it has an antenna gain of 20 log ₁₀ (N) [dB]. FIG. 8 shows an example of UL and LL beam shapes in the second embodiment. In the figure, the beam width of UL (first data signal) shown by the solid line is narrowed, and the beam width of LL (first data signal) shown by the dotted line is widened. As described above, in the wireless communication device of the second embodiment, UL and LL are independently beam-formed.

Since the power of LL is γ [dB] larger than that of UL and UL has an antenna gain of 20 log ₁₀ (N) [dB], the power difference between LL and UL is γ-20 log ₁₀ (N) [dB]. .. As shown in FIG. 8, the LL signal having the broad beam width shown by the dotted line enables broadcast communication of the second data signal with high throughput. In this case, a higher-order modulation multi-value number such as 64QAM or 256QAM is suitable for the modulation multi-value number of LL.

Further, by the UL signal of the pencil beam shown by the solid line, the first data can be transmitted to the terminal in the specific direction in addition to the broadcast transmission of the second data. In this case, it is desirable to use a modulation multi-value number of UL lower than LL such as 16QAM as the modulation multi-value number of UL.

As described above, in the wireless communication device according to the second embodiment, the upper IL control unit 13 and the lower IL control unit 14 emit the LL beam in the UL beam transmission direction and the UL beam width range. The power is adjusted so that it is larger than the radiant power of the UL beam and is equal to or larger than a predetermined power difference. By performing such control, in addition to broadcast transmission, it is possible to transmit another data to a partner in a specific direction with a relatively high throughput.

(Third Example)
The wireless communication device according to the third embodiment of the present invention will be described. In the first and second embodiments, UL and LL were synthesized by the synthesis unit 17 by digital processing. On the other hand, the third embodiment has a configuration in which UL and LL are combined by an analog circuit or spatially combined after antenna output. That is, in the wireless communication device according to the third embodiment, the width of each beam of UL and LL is replaced with the configuration in which the width of each beam of UL and LL is digitally controlled as in the first and second embodiments. Is configured to be controlled by an analog method.

In the case of digital compositing, there is a problem that the scale of the device increases as the number of antenna elements N increases (for example, when N> 32). This problem can be solved by using a hybrid configuration of digital beam formation and analog beam formation, or a configuration of only analog beam formation. In the time division multiplexing transmission in which different beam formations are performed, which is the main object of the present invention, any beam formation method may be used because it does not depend on the beam formation method such as digital beam formation or analog beam formation. In the case of beam scanning, a beam scanning with a lens antenna or a mechanical beam scanning antenna may be used.

The beam control when a parabolic antenna is used will be described below. In this case, the beam width can be controlled by changing the focus of the parabolic antenna.
As shown in FIG. 9, a general parabolic antenna includes a radiator 41 and a reflector 42. The radio wave radiated from the radiator 41 toward the reflector 42 is reflected by the reflector 42, and a beam is formed in the forward direction. At this time, if the focal positions of the radiator 41 and the reflector 42 match, the beam is ideally a parallel beam as shown in FIG. 9, the beam is narrow, and the antenna gain is large. On the contrary, when the focal positions of the radiator 41 and the reflector 42 deviate from each other, the beam becomes wider and the antenna gain becomes smaller.

As shown in FIG. 10, the parabolic antenna that can be used in the wireless communication device according to the third embodiment includes a first radiator 41, a second radiator 51, and a reflector 42. That is, the configuration is such that a second radiator 51 is added to a general parabolic antenna. In the figure, the second radiator 51 is arranged so as to be offset from the focal position of the reflector 42, and the first radiator 41 is arranged so as to be the focal position of the reflector 42. The first radiator 41 transmits a UL signal, and the second radiator 51 transmits an LL signal.

The first radiator 41 is located at the focal position of the reflector 42, has a high antenna gain, and forms a narrow beam (parallel beam). On the other hand, the second radiator 51 is out of the focal position of the reflecting mirror 42, the antenna gain is low, and a wide beam is formed. Therefore, the beam from the first radiator 41 is used to transmit the UL signal, and the beam from the second radiator 51 is used to transmit the LL signal to generate the LDM signal as shown in FIG. Can be done. As described above, in the third embodiment, the width of the UL beam is narrowed and the width of the LL beam is widened by adjusting the arrangement of the first radiator 41 and the second radiator 51. ..

In the third embodiment, it is difficult to electronically scan the UL signal as in the first embodiment, so that it is necessary to mechanically rotate the antenna itself in order to perform the beam scanning. However, on the other hand, it is possible to provide the LDM configuration at a very low cost as compared with the first embodiment.

(Fourth Example)
The wireless communication device according to the fourth embodiment of the present invention will be described. Digital modulation methods used in UL and LL include a synchronous detection method in which information is transmitted by carrying information on absolute amplitude and absolute phase, and a differential detection method in which information is carried on relative amplitude and phase. When performing synchronous detection, it is necessary to grasp the absolute amplitude and absolute phase on the receiving side. On the other hand, when the differential detection method is performed, it is not necessary to grasp the absolute amplitude and the absolute phase because it is assumed that the neighboring times and frequencies have coherentness and the difference is used.

In synchronous detection, a pilot signal whose amplitude and phase are known is often used. Specifically, the pilot signal is distributed over the time and frequency in the band, and the receiving side estimates the characteristics of the transmission line by performing interpolation interpolation in the frequency and time direction for the received pilot signal. To do. Then, in the demodulation process, synchronous detection processing is performed based on the estimated transmission line characteristics.

In the first to third embodiments, the relationship between the amplitude and phase of UL and LL on the transmitting side is not maintained on the receiving side. Therefore, it is necessary to use a pilot signal for demodulating UL and a pilot signal for demodulating LL. Therefore, the UL pilot signal and the LL pilot signal are arranged in the transmission band in such a relationship that they are orthogonal in terms of time, frequency, or code.

FIG. 11 shows an example of arrangement of pilot signals in the fourth embodiment. The horizontal axis of FIG. 11 represents the frequency direction. In the figure, the UL pilot signal and the LL pilot signal are arranged in a relationship orthogonal to each other in the frequency domain.

Next, a case where the orthogonal relationship is maintained in the code region will be described. UL pilot signal P _UL, when the LL pilot signal and P _LL, an even symbol sends a _{_{_{P even = P UL + P LL}}} , on odd symbols for transmitting the P _odd = P _UL -P _LL. On the receiving side, when extracting the UL pilot signal, P _UL = 0.5 (P _even + P _odd ) is calculated, and when extracting the LL pilot signal, P _LL = 0.5 (P _even). -P _odd ) may be calculated.

By arranging the pilot signals in such a relationship that the UL and the LL are orthogonal to each other in this way, it is possible to demodulate even in the synchronous detection method.
Furthermore, it is also possible to realize a combination of synchronous detection and differential detection in UL and LL. In this case, the pilot signal may be arranged only in the synchronous detection layer.
The above description is a method suitable for a multi-carrier system such as an OFDM signal, but even in the single carrier system, a preamble signal whose amplitude and phase are known may be arranged so as to be orthogonal in time. ..

Although the present invention has been described in detail based on the first to fourth examples, it goes without saying that the present invention is not limited to these examples and can be widely applied to other than the above. For example, in the above description, two types of data are transmitted using two layers, an upper layer (UL) and a lower layer (LL), but the data is divided into three or more layers and three or more types of data are transmitted. It may be.
Further, the present invention can be provided, for example, as a method or method for executing the process according to the present invention, a program for realizing such a method or method, a storage medium for storing the program, or the like.

The present invention is effective when transmitting a plurality of different types of data at the same frequency and time.

11: Upper layer modulation unit, 12: Lower layer modulation unit, 13: Upper IL control unit, 14: Lower IL control unit, 15: Upper layer amplitude / phase control unit, 16: Lower layer amplitude / phase control unit, 17: Synthesis part, 18: RF conversion part, 19: Antenna part,
21,31: Base station, 22-24,32: Terminal station,
41, 51: Radiator, 42: Reflector,
100: UL data processing unit, 101: LL data processing unit, 121U: UL error correction coding unit, 121L: LL error correction coding unit, 122U: UL carrier modulation unit, 122L: LL carrier modulation unit, 123U, 123L: Power adjustment unit, 124: Synthesis unit, 125: OFDM modulation unit, 126: Transmission antenna, 130: Reception antenna, 131: OFDM demodulation unit, 132; UL carrier demodulation unit, 133: UL error correction decoding unit, 134: Replica Generation unit, 135: Removal processing unit, 136: LL carrier demodulation unit, 137: LL error correction decoding unit

Claims

In a wireless communication device that transmits multiple data in a time division multiplexing system
An antenna that outputs the first beam that transmits the first data and the second beam that transmits the second data that is different from the first data into space at the same frequency and time.
A power ratio adjusting unit that adjusts the power ratio of the first beam and the second beam,
A beam width control unit for controlling the width of the first beam and the second beam is provided.
The beam width control unit is a wireless communication device characterized in that the width of the first beam and the width of the second beam are controlled to be different from each other.
In the wireless communication device according to claim 1,
The second data is data used for controlling the transmission of the first data.
The beam width control unit is a wireless communication device that controls to narrow the width of the first beam and widen the width of the second beam.
In the wireless communication device according to claim 2,
In the power ratio adjusting unit, the radiant power of the first beam is larger than the radiated power of the second beam and a predetermined power is provided in the transmission direction of the first beam and the width range of the first beam. A wireless communication device characterized in that it is adjusted so as to exceed the difference.
In the wireless communication device according to claim 2,
In the power ratio adjusting unit, the radiant power of the second beam is larger than the radiated power of the first beam and a predetermined power in the transmission direction of the first beam and the width range of the first beam. A wireless communication device characterized in that it is adjusted so as to exceed the difference.
In the wireless communication device according to claim 2,
A wireless communication device characterized in that the second data includes position information of the wireless communication device.
In the wireless communication device according to claim 1,
The beam width control unit is a wireless communication device characterized in that the widths of the first beam and the second beam are digitally controlled.
In the wireless communication device according to claim 1,
The beam width control unit is a wireless communication device characterized in that the widths of the first beam and the second beam are controlled by an analog method.
In the wireless communication device according to claim 1,
The antenna radiates a reflecting mirror, a first radiator that radiates a radio wave of the first data to the reflecting mirror to generate the first beam, and a radio wave of the second data to the reflecting mirror. It has a second radiator that generates the second beam and
The beam width control unit is characterized in that the widths of the first beam and the second beam are controlled by adjusting the position of the first radiator and the position of the second radiator with respect to the reflector. Wireless communication device.
In the wireless communication device according to claim 1,
The feature is that the pilot signal used for demodulation of the first data and the pilot signal used for demodulation of the second data are arranged and transmitted in an orthogonal relationship in the region of time, frequency, or code. Wireless communication device.
In a wireless communication device that transmits multiple data in a time division multiplexing system
An antenna that outputs the first beam that transmits the first data and the second beam that transmits the second data that is different from the first data into space at the same frequency and time.
A power ratio adjusting unit that adjusts the power ratio of the first beam and the second beam,
A wireless communication device including a beam width control unit that controls the width of the first beam and the width of the second beam.