WO2007108430A1

WO2007108430A1 - Wireless communication device and wireless communication system

Info

Publication number: WO2007108430A1
Application number: PCT/JP2007/055481
Authority: WO
Inventors: Shinya Fukuoka
Original assignee: Pioneer Corporation
Priority date: 2006-03-17
Filing date: 2007-03-19
Publication date: 2007-09-27
Also published as: JP2009135559A

Abstract

[PROBLEMS] Efficient communication is carried out in accordance with various communication partners. [MEANS FOR SOLVING THE PROBLEMS] Prior to starting communication, a total directionality of antennas (101A-F) is set to a prescribed initial state. In this state, in response to initial communication contents in which communication is carried out with other wireless communication device (301), communication conditions of the number of the antennas, a communication system, etc., are set for communication thereafter with the other wireless communication devices. With this setting, a wireless communication device is provided with functions that are achievable for an MIMO communication but the MIMO communication system is not always used for the wireless communication device because it depends on initial communication contents with the other communication devices (301), so that communication can be carried out in a communication mode in compliance with requirements of the other communication devices (301).

Description

Specification

Wireless communication apparatus and wireless communication system

Technical field

The present invention relates to a wireless communication apparatus that can be used in a multiple input multiple output (MIMO) type wireless communication system and a wireless communication system including the same.

Background art

[0002] In recent years, information transmission systems via wireless communication have been configured with multiple antennas on both the transmitting and receiving sides to form a multi-input multi-output system via a wireless transmission path (channel). The M IMO method is attracting attention. When communication is performed with M transmit antennas and N receive antennas, the channel response between transmission and reception is represented by the matrix A of NXM. This matrix A can be further decomposed using eigenvalues of correlation matrices AA ^H and A ^H A (subscript H is complex conjugate transpose) and eigenvectors corresponding to each (singular value decomposition). In this case, the MIMO scheme in a multipath environment can have min (M, N) independent channels, so the availability of space can be increased by increasing the number of transmit / receive antennas. The transmission performance of the MIMO scheme at this time can be grasped by obtaining channel characteristics by using the eigenvalues of the correlation matrix.

As such a MIMO wireless communication apparatus, for example, a technique described in Patent Document 1 has already been proposed. In this wireless communication apparatus according to the prior art, the weighting control means calculates a channel matrix that reduces eigenvalue variations, and controls the directivity of the adaptive array antenna so that the current channel matrix approaches the channel matrix. In this way, the channel capacity is improved.

Patent Document 1: Japanese Patent Laid-Open No. 2005-45351 (paragraph numbers 0037 to 0055, FIGS. 9 to 11) Disclosure of the Invention

Problems to be solved by the invention

[0005] In the wireless communication device according to the above-described conventional technology, among the channel capacity of Shannon that determines the maximum signal transmission rate per frequency, the channel capacity that can be used for actual communication is not used. The focus is on improvement. By reducing the variation in eigenvalues by the weighting control means, the variation in channel capacity corresponding to these eigenvalues is also reduced, and as a result, the channel capacity corresponding to all eigenvalues is effectively used for actual communication. It can be done.

[0006] By the way, the background of the rapid spread of mobile phones in recent years and technological innovation in communication systems, further progress in OA equipment-monolithic office equipment, networking of personal computer environments using wireless LAN, etc. Below, it is not always the best to always try MIMO communication, regardless of the communication partner, even with the MIMO communication device described above. For example, to meet the various needs of users, the power of data to be transmitted is text-only mail, the power of images, the power of music, or what is the required transmission rate? For example, it is most efficient to use a shifted communication method such as MIMO, normal adaptive array method, diversity method, etc. The same applies to the number of antennas used in the wireless communication device for communication. In addition, the communication partner's antenna has only one element! It has multiple elements that are capable of MIMO communication! / The optimal mode of selection and control of the communication system, the number of antennas, etc. will vary depending on the power of the system.

[0007] In the above prior art, since the MIMO system communication is always performed regardless of the communication partner, it is difficult to reliably realize communication because of the efficiency corresponding to various communication partners. there were.

[0008] The problems to be solved by the present invention include the above-described problems as an example.

Means for solving the problem

[0009] In order to solve the above-described problem, the invention according to claim 1 is a wireless communication apparatus that can be used in a multiple-input multiple-output wireless communication system, wherein m is an integer of 2 or more, and a plurality of The initial control means for controlling each antenna so that the m antennas each having an antenna element and the directivity realized by all these m antennas are in a predetermined initial state, and the initial control means. Communication condition control means for setting a communication condition in communication with the other wireless communication device according to the content of initial communication with the other wireless communication device in the realized initial state. [0010] In order to solve the above problem, the invention according to claim 11 is a wireless communication system including a wireless transmission device and a wireless reception device, and capable of multi-input multiple-output communication, wherein the wireless transmission And at least one of the apparatus and the wireless receiving apparatus, when m is an integer greater than or equal to 2, m antennas each having a plurality of antenna elements enclosed or loaded in a dielectric and arranged at predetermined intervals from each other; The directivity realized by all these m antennas is an initial control means for controlling each antenna so as to be in a predetermined initial state, and the other wireless communication apparatus in the initial state realized by the initial control means. Communication condition control means for setting communication conditions in communication with the other wireless communication device according to the initial communication content.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a system configuration diagram illustrating an overall outline of a wireless communication system including the wireless communication device of the present embodiment.

In the wireless communication system S shown in FIG. 1, the wireless communication device 1 of the present embodiment includes a plurality of (six in this example) antennas 101A, 101B, 101C, 101D, 101E, 101F, and these antennas 101A. And a control device 200 for controlling the operation of F. The wireless communication device 1 is configured to be able to communicate via the antennas 101A to 101F by a multiple input multiple output (MIMO) method, as will be described in detail later. Communication with another wireless communication apparatus 301 using at least one of the antennas 101A to 101F based on the control of the overall control unit 201).

FIG. 2 is a perspective view showing a detailed structure of antenna 101A shown in FIG. 1, and FIG. 3 is an explanatory diagram for explaining a control system of antenna 101A. 2 and 3, the antenna 101A includes a dielectric substrate 110 made of, for example, polycarbonate, a ground conductor 111 formed on substantially the entire upper surface of the dielectric substrate 110, and the ground conductor 111. A plurality of antennas (seven in this example) formed so as to be embedded in the dielectric 120 in a state where the dielectric 120 formed in a substantially cylindrical shape and the ground conductor 111 are electrically insulated from each other. With element P.

[0015] The antenna element P is a monopole whose longitudinal direction is perpendicular to the plane of the ground conductor 111. It consists of one feeding antenna element PO (feeding element) and at least one (six in this example) parasitic antenna elements P1 to P6 (parasitic elements).

The feed antenna element PO includes a cylindrical radiating element 106 that is electrically insulated from the ground conductor 111 and embedded in a dielectric 120. A signal line is connected to one end of the radiating element 106 so that a radio signal fed from the control device 200 is fed and radiated to the feeding antenna element P0 via an RF circuit 290 (described later). It becomes.

[0017] The parasitic antenna elements P1 to P6 are arranged so as to have a substantially circular shape in this example at a predetermined interval with respect to the feeding antenna element P0. Each parasitic antenna element P1 to P6 includes a substantially cylindrical non-excitation element 107 that is electrically insulated from the ground conductor 111 and disposed so as to penetrate the dielectric substrate 110 and the dielectric 120 in the vertical direction. Yes. One end of each non-excitation element 107 has a variable reactance element 130 having a predetermined reactance value (for example, also having a variable capacitance diode force), and a through-hole conductor 114 formed by filling the dielectric substrate 110 in the vertical direction. The ground conductor 111 is grounded at a high frequency via

[0018] At this time, the lengths of the radiating element 106 and the non-exciting element 107 in the longitudinal direction are substantially the same. For example, when the variable reactance element 130 has inductance (L property), it is variable. The reactance element 130 becomes an extension coil, and the electric lengths of the parasitic antenna elements P1 to P6 are longer than those of the feeding antenna element PO, and function as a reflector. On the other hand, for example, when the variable reactance element 130 has capacitance (C-type), the variable reactance element 130 becomes a shortening capacitor, and the electric lengths of the parasitic antenna elements P1 to P6 are compared with the power supply antenna element P0. It becomes shorter and works as a director. That is, by changing the reactance value in the variable reactance element 130 that changes the control voltage applied to the variable reactance element 130, the electric length of the parasitic antenna element P1 including the non-excitation element 107 is changed to the feed antenna element P0. By changing the comparison, the horizontal plane directivity of the antenna 101A can be changed.

[0019] It should be noted that the above-described force is described taking antenna 101A as an example, and the other antennas 101B to 101F have the same configuration, and similar control is performed.

FIG. 4 is a functional block diagram showing a detailed configuration of the control device 200 shown in FIG. 1, and FIG. FIG. 6 is a functional block diagram showing a detailed configuration of functions related to the transmitting side, and FIG. 6 is a functional block diagram showing a detailed configuration of functions related to the receiving side in FIG.

In FIG. 4, FIG. 5, and FIG. 6, the control device 200 is connected to each of the feeding antenna elements PO of the m antennas 101 (m = 6 in this example), and is provided in common for transmission and reception. RF circuit (may be further via an IF circuit) 290, m corresponding to each of the received signals from the m antennas 101, LPF242 that limits the band of each received signal, and analog-digital conversion The AZD converter ^^ 241, the frequency converter 300 that receives these m AZD converters ^ 241 power, and performs processing such as demodulation, and the received signal demodulated by the frequency converter 300 A receiving-side digital directivity control unit 250 (feeding-side control means) that performs predetermined reception directivity control processing (for example, composed of digital filters corresponding to complex numbers of I and Q components), and this receiving-side digital directivity control unit For example, the OFDM method A reception-side signal processing unit 260 that performs a known demodulation process based on the FM method, an error state monitoring circuit 204 that monitors occurrence of processing errors in the reception-side signal processing unit 260, and a monitoring result of the error state monitoring circuit 204 And a selection circuit 270 that selects a signal demodulated by the reception-side signal processing unit 260, and a decoding unit 271 that decodes the signal (demodulated wave) selected by the selection circuit 270 by a predetermined known method, And a response bit string interpretation unit 272 that interprets the decoded signal decoded by the decoding unit 271 and reads out received data (information signal) received by the antenna 101 from the communication partner.

[0022] Further, the control device 200 further generates a command bit string generating unit 274 that generates a command bit string corresponding to transmission data to be transmitted from the antenna 101, and a digital signal output from the command bit string generating unit 274 is predetermined. An encoding unit 273 that encodes by the above method, and a transmission-side signal processing unit 210 that receives a signal encoded by the encoding unit 273 and performs a known modulation process based on, for example, the OFDM scheme or the FM scheme, The frequency conversion unit 310 that performs predetermined processing such as modulation on the signal from the transmission side signal processing unit 210, and the transmission directivity control processing are performed on the signal from the frequency conversion unit 310 (for example, I Digital filter power corresponding to the complex number of the component and Q component) (transmission side digital directivity control unit 220 (power supply side control means)) and the transmission signals to m antennas 101 respectively. DZA converter output to the m digital-to-analog converter after the RF circuit 290 is provided A key for performing a predetermined directivity control process using the device 232 and a plurality (6 in this example) of parasitic antenna elements P1 to P6 of m antennas (m = 6 in this example) 101. Analog directivity control unit 280 (parasitic side control means) and m signals corresponding to each of m antennas 101 are provided, and the signals from analog directivity control unit 280 are converted into digital signals after analog conversion. DZA converter 292 that outputs control voltage to parasitic antenna elements P1 to P6 of each antenna 101, receiver digital directivity control unit 250, transmission digital directivity control unit 220, analog directivity control unit 280, etc. And an overall control unit 201 for controlling the overall components.

[0023] The frequency converter 310 is provided with m systems corresponding to the number m of antennas 101 (m = 6 in the above example). Transmission digital that outputs a digital signal (for example, a sine wave sampled signal) that forms a transmission signal (carrier wave) Fc to the communication partner based on the sampling value stored so as to correspond to each phase at a fixed sampling point One signal output unit 213 is provided

[0024] Further, each of the m systems is used for modulating the carrier wave Fc from the transmission digital signal output unit 213 to be transmission information based on the information signal (data) encoded by the encoding unit 203. Modulators (multipliers) that output modulated signals (for example, generate I and Q components by GFSK modulation) 212-0, 212-1, 2, 212-n, and these multipliers 212-0, 212-1,..., 212—n Let each of the I component and Q component signals of the specified frequency pass through BPF211aO, 211b0, 211al, 211bl, ···, 21 lan, 21 lbn I have.

[0025] The transmission-side digital directivity control unit 220 is also provided with m systems corresponding to the above, and each system is synthesized through the BPF211aO, 211b0, 211al, 211bl, ..., 21lan, 211bn, respectively. For the combined signal, a total of n + 1 weights for obtaining a predetermined transmission directivity based on the corresponding coefficients (phase control signals) from the overall control unit 201 such as CIO, C11,. , 221an, n = 6) coefficient multipliers 221a0, 221al,..., 221an and adders 222 for synthesizing outputs from these n + 1 coefficient multipliers 221a0 to an. The output from the adder 222 of each system is the above-mentioned DZA converter 232, RF circuit Supplied to the feeding antenna element PO of the corresponding antenna 101 via the path 290, respectively.

[0026] The frequency converter 300 is provided with m systems in the same manner as described above, and each system converts the complex I component and Q component included in the weighted received signal output from the A ZD converter 241. On the other hand, a total of n + 1 pairs (in this example, n = 6) of coefficient multipliers 261a and 261b for multiplying digital signal bit sequences orthogonal to each other and performing IQ quadrature demodulation (orthogonal detection), and these n + 1 pairs And an FIR filter unit 262 that combines the outputs from the coefficient multipliers 261a and 261b and performs predetermined filtering.

[0027] Similarly to the above, the receiving-side digital directivity control unit 250 is provided with m systems corresponding to the number m of antennas 101 (m = 6 in the above example), and each system outputs from the FIR262. With respect to the received signal, a total of n + 1 weights for obtaining a predetermined transmission directivity based on the corresponding coefficients (phase control signals) D10, D11,. In this example, n = 6) coefficient multipliers 251— 0, 251-1,..., 251—n, and an adder that combines the outputs from these n + 1 coefficient multipliers 251—0 to 251—n 252 and each.

[0028] An error detector (such as a CRC detector) (not shown) is connected to the reception side signal processing unit 260 (for example, connected to the adder 252), and the error state monitoring circuit 204 is connected to the reception side signal processing unit 260. The error detection signal is also supplied to the selection circuit 270 according to the error detection signal supplied (the error state monitoring circuit 204 uses the monitoring result corresponding to the detection signal as information such as an error flag). Also output to the overall control unit 201). This selection command signal instructs the error detector to select the output of the system that has output a normal detection result, and the selection circuit 270 corresponds to the selection command signal among the signals of each system. The selected signal is selected and output to the decoding unit 271.

[0029] In this way, the output from the adder 252 of each system is selected by the selection circuit 270 via the reception side signal processing unit 260, then decoded by the decoding unit 271, and further the response Bit string interpretation unit 2 Interpreted at 72 and taken out as received information. Thereby, after the communication with the communication partner such as the other wireless communication device 301, the power with which the communication partner requests the wireless communication device 1 of the present embodiment, that is, the other wireless communication device 301 antenna (element ) Number, application of the other party (power of communication content is image, voice, power of text-only file, email, etc.), and how much data transfer time • Real time · Power · Whether the user's desired priority order is requested can be acquired by the overall control unit 201 as information.

[0030] It should be noted that each system of the reception-side signal processing unit 260 is also provided with an RSSI (Received Signal Strength Indicator) circuit (not shown). The RSSI detection signal “R SSIj is received signal strength (reception Electric field intensity) information is input to the overall control unit 201.

FIG. 7 is a flowchart showing a control procedure executed by the overall control unit 201 provided in the control device 200 of the wireless communication device 1 of the present embodiment. In FIG. 7, first, in step S5, initial setting processing is performed so that the total directivity by all (six in this example) antennas 101 becomes substantially omnidirectional. Specifically, for example, a control signal is output to the analog directivity control unit 280, and directivity by the parasitic antenna elements P1 to P6 in each of all (six in this example) antennas 101 is a predetermined value (predetermined direction). (See FIG. 8 to be described later), and the control coefficients D10 to Dmn to the reception-side digital directivity control unit 250 and the control coefficients C10 to Dmn to the transmission-side digital directivity control unit 220 are set to predetermined values. Thus, the initial setting control is performed so that the total directivity by all the antennas 101 becomes substantially omnidirectional in almost all directions. At this time, the directivity (region) of each adjacent antenna 101 is controlled so as to overlap each other (see FIG. 8 described later). These initial setting values may be set appropriately by the operator (or at the time of factory shipment).

Thereafter, the process proceeds to step S10, and under the initial settings set in step S5, the command bit string generation unit 274, the encoding unit 273, the transmission side signal processing unit 210, the frequency conversion unit 310, and the transmission side digital directivity control Each unit 220 is controlled to transmit a beacon signal from the antenna 101 and wait in a standby state. FIG. 8 is an explanatory view schematically showing a radio wave radiation mode in the standby state after the initial setting. As described above, the directivities (regions) of the adjacent antennas 101 overlap each other! /.

[0033] Then, in step S20, in response to the beacon signal, a response signal having a communication partner such as another wireless communication device 301 is transmitted to the frequency converter 300, the receiving-side digital directivity control. The control unit 250 and the receiving side signal processing unit 260 determine whether the response is received without error by the response bit string interpretation unit 272 via the selection circuit 270 and the decoding unit 271. If the response signal is not received at all or an error occurs even if it is received (detected by an error flag from the error state monitoring circuit 204, etc.), this determination is not satisfied and the process returns to step S10. Continuing, I will continue waiting.

If a response signal from another wireless communication device 301 or the like is received without error, the determination at step S 20 is satisfied, and the routine goes to step S 100. In step S100, based on the interpretation result (reception result) of the received response signal, the content of communication with the other wireless communication device 301 is confirmed (the number of antenna elements such as the other wireless communication device 301 and the required transmission). Confirmation of various information such as rate and received strength) and corresponding communication condition setting processing on the wireless communication device 1 side is performed.

FIG. 9 is a flowchart showing the detailed procedure of step S100. First, in step S105, based on the reception result of the response signal, it is determined whether the number of antenna elements of the other wireless communication device 301 or the like as the communication partner is one. If the other wireless communication apparatus 301 has only one antenna element instead of two or more, the determination is satisfied, and the routine goes to Step S110.

In step S110, based on the reception result, it is determined whether or not the transmission rate (transmission speed) requested from the other wireless communication apparatus 301 is relatively high (for example, whether it is larger or smaller than a predetermined threshold value). Compare). If the required transmission rate is relatively low, the determination is not satisfied and the routine goes to Step S115.

[0037] In step S115, based on the reception result, it is determined whether or not the received signal strength (detected by the RSSI circuit) at the time of receiving a response signal from another wireless communication apparatus 301 is relatively large (for example, a predetermined value). Compare the magnitude with the threshold). If the received signal strength is relatively large, the determination is satisfied, and the routine goes to Step S120, where, for example, the received signal strength of the m antennas 101 (m = 6 in this example) is the highest (or the error rate is low). Each unit can be used to continue communication with the other wireless communication device 301 without changing the directivity (set in a predetermined direction in step S5) of the antenna 101. A control signal is output to On the other hand, the received signal strength is relatively low In this case, the determination of step SI 15 is not satisfied, and the process proceeds to step SI 25. For example, the received signal strength is maximum (or the error rate is the lowest) among m antennas 101 (m = 6 in this example). The antenna 101 may have a directivity (set in a predetermined direction in step S5) to be substantially omnidirectional in almost all directions to communicate with another wireless communication apparatus 301. Control signals are output to the transmission-side digital directivity control unit 220, the reception-side digital directivity control unit 250, the analog directivity control unit 280, etc.

On the other hand, if the transmission rate (transmission speed) requested from the other wireless communication device 301 is relatively high in step S110, the determination is satisfied and the routine goes to step S130. In step S130, as in step S115 described above, it is determined whether or not the received signal strength at the time of receiving a response signal from another wireless communication apparatus 301 is relatively high. If the received signal strength is relatively high, the determination is satisfied, and the process proceeds to step S135. Among m antennas 101 (m = 6 in this example), for example, predetermined (eg, the received signal strength is high or the error rate is low). V,) A control signal is output to each part so as to perform known diversity control using N antennas 101 (where N≤m). On the other hand, if the received signal strength is relatively small, the determination in step S130 is not satisfied, and the procedure moves to step S140. For example, among m antennas 101 (m = 6 in this example) (Or low error rate) N digital (N ≤ m) antennas 101 are used to perform known adaptive array control 220 digital directional control unit 220, digital directional control unit 250, analog 250 A control signal is output to the directivity control unit 280 or the like.

In step S105, if the number of antenna elements of the other wireless communication device 301 or the like as the communication partner is two or more, the determination is not satisfied, and the routine goes to step S145. In step S 145, as in step S 110, based on the reception result, it is determined whether or not the transmission rate (transmission speed) requested by the other wireless communication device 301 is relatively high. If the required transmission rate is relatively low, the determination is not satisfied and the routine goes to Step S130 described above, and thereafter the same procedure as described above is performed. If the required transmission rate is relatively high, the process moves to step S150, and N (for example, the received signal strength is high or the error rate is low) out of m (m = 6 in this example) antennas 101 (for example, N≤m) antenna 101 Used to control the transmission-side digital directivity control unit 220, the reception-side digital directivity control unit 250, the analog directivity control unit 280, etc. so as to perform communication using the known multiple input multiple output (MIMO) method. Output a signal.

[0040] Although the above has described an example in which various communication conditions are set depending on the number of antenna elements, the required transmission rate, and the received signal strength, the present invention is not limited to this, and the received signal strength can be acquired. Other information, for example, the application of the other user (whether the content of the communication is an image, voice, power of a text-only file, mail, etc.) and how much data transfer time You may request real-time performance, power, user preference, etc., and set the above communication conditions based on whether or not.

[0041] When Step S120, Step S125, Step S135, Step S140, and Step S150 are completed as described above, the process proceeds to Step S155, and among m antennas 101, Step S120, Step The same processing as in step S5 is performed so that the total directivity by the remaining antennas 101 other than those used in S125, step S135, step S140, and step S150 becomes substantially omnidirectional. Note that the communication operation of these remaining antennas 101 may be stopped. When step S155 is completed, the routine ends.

Returning to FIG. 7, when step S100 is completed as described above, the process proceeds to step S25, where the command bit string generation unit 274, encoding is performed under the communication condition setting described above in step S100. The unit 273, the transmission side signal processing unit 210, the frequency conversion unit 310, and the transmission side digital directivity control unit 220 are each controlled to transmit a signal from the antenna 101 and start communication with another wireless communication device 301.

FIG. 10 and FIG. 11 are explanatory diagrams schematically showing a communication mode with another wireless communication device 301 executed at this time. FIG. 10 shows the result of setting in step S120 where the number of antenna elements of the other wireless communication apparatus 301 is one, the required transmission rate is low, and the received signal strength is large. An example of a state in which the directivity (set in a predetermined direction in step S5) provided to the antenna 101 is continued and communication with another wireless communication device 301 is continued is shown.

On the other hand, FIG. 11 shows that the setting is performed in step S140 where the number of antenna elements of other wireless communication apparatus 301 is one, the required transmission rate is high, and the received signal strength is low. As a result, N antennas 101E and 101F (N = 2 in this example) are controlled so that the sensitivity (transmission or reception) is maximized for the other wireless communication device 301 by adaptive array control. An example of the state of being performed is shown.

[0045] Also, in the case where the number of antenna elements of other wireless communication apparatus 301 is two or more and the required transmission rate is high, in step S150! /, MIMO is performed using N antennas 101. Although communication is performed, FIG. 12 is a conceptual explanatory diagram conceptually showing the behavior of this MIMO communication. In this figure, for the sake of clarity, the number of antennas 101 in the wireless communication device 1 of this embodiment is three, and the other wireless communication device 301 that is the communication partner is also in this embodiment. It is illustrated as having the same configuration as that of the wireless communication device 1 of the embodiment. As shown in the figure, when communication is performed between the three transmission antennas 101 of the wireless communication device 1 and the three reception antennas 101 of the other wireless communication devices 301, the channel response between transmission and reception is represented by a 3 × 3 matrix. The In this case, in MIMO communication under a multipath environment, 3 X 3 = 9 transmission paths (channels) can be virtually made into 3 independent channels by eigenvalue conversion as shown in the figure. The availability of space can be increased.

[0046] Returning to FIG. 7, when step S25 is completed as described above, the process proceeds to step S30, where it is determined whether the operator's force is also a force for which a communication end instruction has been issued. If an instruction to stop wireless communication is given by an operator or the like via an unillustrated operating means provided in the wireless communication device 1, this determination is satisfied and the flow ends. This determination is not satisfied until a stop instruction is issued, and the process proceeds to step S35.

[0047] In step S35, as in step S10, a beacon signal is transmitted to enter a standby state. At this time, the 1 to N antennas set in Step S 120, Step S 125, Step S 135, Step S 140, and Step S 150 are already used for communication with other wireless communication devices 301. So, for example, send the beacon signal using only the remaining antennas 101!

[0048] Thereafter, the process proceeds to step S35, and in the same manner as in step S20 described above, another communication partner such as another wireless communication device 302 appears corresponding to the beacon signal, and the response signal therefrom is a frequency converter 300, Received by receiving side digital directivity control unit 250 and receiving side signal processing unit 260 and received via selection circuit 270 and decoding unit 271 and received by bit string interpretation unit 272 without error. Determining whether or not the power is trusted. If the response signal is not received at all, or if an error occurs even if it is received, this determination is not satisfied, and the procedure returns to step S25 and the same procedure is repeated.

[0049] If a response signal of another radio communication apparatus 302 isotropic power is received without error, the determination at step S40 is satisfied, and the routine goes to step S200. In step S100, processing equivalent to that in step S100 is performed, and based on the interpretation result (reception result) of the received response signal, the content of communication with the other wireless communication device 302 is confirmed (the antenna element (Confirmation of various information such as number, required transmission rate, reception strength, etc.) and corresponding communication condition setting processing on the wireless communication apparatus 1 side is performed. For example, the details shown in FIG. 10 are sufficient as in step S 100 0, and the description thereof is omitted.

[0050] When step S200 is completed, the process proceeds to step S45, and in the same manner as step S25 described above, the command bit string generation unit 274, the encoding unit 273, and the transmission are performed in step S200 under the communication condition setting described above. The side signal processing unit 210, the frequency conversion unit 310, and the transmission side digital directivity control unit 220 are controlled to transmit signals from the antenna 101, and communication with the other wireless communication device 302 is started.

FIG. 13 is an explanatory view schematically showing a communication mode with still another wireless communication device 302 executed at this time. FIG. 13 shows that when communication with another wireless communication apparatus 301 having one antenna element is already performed by the antennas 101E and 101F by the adaptive array system, another wireless communication apparatus 302 appears, As a result of the setting in step S150 of FIG. 10 where the number of antenna elements of wireless communication apparatus 302 is two and the required transmission rate is high (for example, antennas 101A, 101B, 101C, (The antenna with the highest received power among 101D and the one after it is selected) Antenna 101B and 101C are used to start communication with the other wireless communication device 302 using the MIMO scheme. An example is shown.

Returning to FIG. 7, when step S45 is completed as described above, the process returns to step S40, and the same procedure is repeated.

FIG. 14 is a diagram illustrating an actual application example of the wireless communication device 1 of the present embodiment having the above-described configuration. In FIG. 14, in this example, the inner pad located in the front of the interior of the car AM. The radio communication device 1 is installed on the side opposite to the steering wheel switch (front passenger seat side), and the antenna CT (not shown) is installed on the rear side (rear seat side). Etc.) are provided. Communication is performed between the plurality of antennas 101 of the wireless communication apparatus 1 and the television CT, and the other plurality of antennas 101 and the ground-side base station BP (corresponding to the above-described other wireless communication apparatus 301 and the like). Or, it may be an artificial satellite). At this time, the wireless communication device 1 functions as a wireless transmission device or a wireless reception device, and the wireless communication device 1, 301, 301 constitutes the wireless communication system S.

FIG. 15 is a diagram illustrating another application example of the wireless communication device 1 of the present embodiment. In FIG. 15, in this example, the wireless communication device 1 is provided in the inner panel IP in each of the two automobiles AM and AM, as in FIG. Then, communication (so-called inter-vehicle communication) is performed between the two wireless communication apparatuses 1 and 1 using, for example, a plurality of antennas 101. In this case, paying attention to one radio communication device 1, the other radio communication device 1 corresponds to the other radio communication device 301 described above, and the radio communication device 1, 301 constitutes the radio communication system S. ing. The wireless communication device 1 functions as a wireless transmission device or a wireless reception device.

[0055] In the above, step S5 of the flow shown in Fig. 7 executed by the overall control unit 201 provided in the control device 200 of the wireless communication device 1 is realized by all the m antennas according to each claim. An initial control means for controlling each antenna so that the directivity to be in a predetermined initial state is configured. In addition, step S100 is a communication condition for setting communication conditions for communication with the other wireless communication device according to the initial communication content with the other wireless communication device in the initial state realized by the initial control means. The control means is configured.

[0056] Further, Step S120, Step S125, Step S135, Step S140, and Step S150 of the flow shown in FIG. 10 may be performed by using a communication method, a multi-input multiple-output method, an adaptive array method, or In addition to configuring the communication method control means to control the diversity method! /, The communication method control means to configure the number of antennas to be set to N as the communication condition.

[0057] Further, in step S155, the antenna set by the antenna number control means is set as the communication condition. The directivity control means is configured to control the directivity of the plurality of antenna elements in the remaining antennas in a predetermined manner based on the number of antennas.

[0058] As described above, the wireless communication device 1 according to the present embodiment is the wireless communication device 1 that can be used in the wireless communication system S of the multiple-input multiple-output method, and m is an integer of 2 or more. M antennas 101 each having a plurality of antenna elements P0 to P6, and initial control means for controlling each antenna so that the directivity realized by these m antennas 101 as a whole is in a predetermined initial state (this In the example, step S5) executed by the overall control unit 201) and communication with the other wireless communication device 301 according to the initial communication content with the other wireless communication device 301 in the initial state realized by the initial control means S5. Communication condition control means (in this example, step S100 executed by the overall control unit 201) for setting the communication conditions in FIG.

[0059] The wireless communication device 1 of the present embodiment! /, Before communication starts! /, First, the initial control means S5 has a plurality of (six in this example) antennas 101A to 101F as a whole. The directivity by is set to the predetermined initial state. In this initial state, the communication condition control means S100 sets the communication conditions for the subsequent communication with the other wireless communication device 301 in accordance with the initial communication content that has been communicated with the other wireless communication device 301. . As a result, while having the performance capable of realizing the multi-input multi-output method, depending on the initial communication content with the other wireless communication device 301, the other wireless communication is not concerned with the communication of the multi-input multi-output method. Wireless communication can be executed in a communication mode that matches the communication device 301. As a result, efficient communication corresponding to various communication partners can be reliably realized.

[0060] In the wireless communication device 1 in the above embodiment, the communication condition control means S100 is a communication condition selected from a multi-input multi-output system, an adaptive array system, and a diversity system. It is characterized by having a communication system control means (step S120, step S125, step S135, step S140, and step SI50 executed by the overall control unit 201 in this example) for controlling to the communication system.

[0061] This allows control (MIMO communication) to perform large-capacity transmission using multiple transmission paths or high-efficiency transmission using a single transmission path, and direction by m antennas 101 (m = 6 in this example). Control that maximizes the sensitivity to the communication partner (adaptive array control) and multiple keys Realize control (diversity control), etc. that uses the antenna 101 signal with excellent radio wave conditions preferentially for the same signal received by the antenna 101, ensuring efficiency with the communication partner and ensuring communication Can do.

[0062] In the wireless communication device 1 in the above embodiment, the communication method control means S100 uses the adaptive communication method as the communication method when the other wireless communication device 301 includes an antenna having one antenna element force. It is characterized by.

[0063] Thereby, the directivity realized by the m antennas 101 (m = 6 in this example) is controlled so that the sensitivity is maximized with respect to the antenna having the one antenna element force. Communication with the antenna can be performed reliably (see Fig. 11).

[0064] In the wireless communication device 1 in the above embodiment, the communication condition control unit S100 controls the number of antennas by setting N as an integer of 1 to m and the number of antennas to be used as N as a communication condition. Means (in this example, step S120, step S125, step S135, step S140, and step S150 executed by the overall control unit 201).

[0065] The antenna number control means S 120, S125, S135, S140, and S150 correspond to various communication partners, and by appropriately setting the number m of antennas 101 within a range of l≤N≤m, Wireless communication can be reliably executed in a communication mode that matches the wireless communication device 301.

[0066] In the wireless communication device 1 in the above embodiment, the communication condition control means S100 is based on the number of antennas 101 set by the antenna number control means S120, S125, S135, S140, and S150 as communication conditions. The other antenna 101 has directivity control means for controlling the directivity by the plurality of antenna elements P0 to P6 in a predetermined manner (in this example, step S155 executed by the overall control unit 201). And

[0067] By controlling the directivity of each antenna 101 that is not used in a predetermined manner, in addition to the communication that is being performed by the antenna 101 that is in use, another communication partner (in this example, a wireless communication device) 302. See Fig. 13 etc.), and it will be possible to establish a standby system for smoothly starting communication.

[0068] In place of the directivity control means S155, the communication condition control means S100 uses the antenna number control means S120, S125, S135, S140, and S150 as communication conditions. If power supply control means for stopping the power supply to the remaining antennas 101 is provided based on the number of the tena 101, the power supply to the antennas 101 can be stopped by using Wasteful power consumption can be avoided.

[0069] In the wireless communication device 1 in the above embodiment, the plurality of antenna elements P0 to P6 of the antenna 101 are provided with a power feeding element P0 to which a signal is fed and a predetermined distance from the power feeding element P0. It includes at least one parasitic element P1 to P6 that is not fed with a signal, and is characterized in that it is enclosed or loaded in a dielectric and arranged at a predetermined distance from each other.

[0070] An ESPAR antenna that includes a feeding element PO and parasitic elements P1 to P6 and whose directivity can be controlled by reactance control to the parasitic elements P1 to P6, and further uses these elements P0 to P6 as dielectrics. By enclosing (or loading), the antenna 101 can be downsized.

[0071] In the wireless communication device 1 in the above embodiment, the communication condition control means S100 determines the directivity of the feeding element PO provided in the m antennas 101 (m = 6 in this example) as a communication condition. Feed-side control means to control (in this example, the transmission-side digital directivity control unit 220 and the reception-side digital directivity control unit 250), and the parasitic elements P1 to P6 included in the m antennas 101 as communication conditions It is characterized by having non-feed-side control means (in this example, the analog directivity control unit 280) for controlling the directivity of the signal.

[0072] When the directivity control of the entire m antennas 101 is performed only on the feeding element P0 side of each antenna 101 that becomes a digital control system, the number of antennas and RF circuit systems and the digital processing corresponding to them are large. It will be a powerful one. On the other hand, in the case where directivity control such as adaptive operation is to be performed only by the parasitic element side P1 to P6 of each antenna 101 serving as an analog control system, the digital processing becomes significant as described above.

[0073] In the wireless communication device 1 of the present embodiment, a rough setting of directivity is first performed by the non-feed-side control means 280, as schematically shown in FIG. Next (see region G1), more directivity control is performed by the power supply side control means 220 and 250 (see region G2), and by using these together, the directivity can be further improved. (See area G). Moreover, the flexibility as the directivity control system can be improved.

[0074] In the wireless communication device 1 in the above embodiment, the initial control means S5 is the initial state. As a feature, the antennas 101 are controlled so that the directivities of the adjacent antennas 101 of the m antennas 101 partially overlap each other.

[0075] In a state where the directivities of the adjacent antennas 101 do not overlap each other, this can be detected when a signal from the other wireless communication device 301 to the wireless communication device 1 happens to reach only the non-overlapping region. Communication is impossible. In the wireless communication device 1 of the present embodiment, the directivity (region) of the adjacent antennas 101 in the initial state is overlapped (see FIG. 8), so that communication can be performed reliably while avoiding the above-described adverse effects. You can.

Note that the present embodiment is not limited to the above, and various modifications can be made. Hereinafter, such modifications will be described step by step.

[0077] (1) When a plurality of adjacent antennas are selected

That is, in the above embodiment, when control is performed so that a plurality of N antennas are used in step S135, step S140, and step S150 of the flow shown in FIG. This is the case of selecting. This modification will be described with reference to FIG.

In FIG. 17, a wireless communication device 1 including six antennas 101A to 101E first communicates with another wireless communication device 301 through two antennas 101E and 101F, and then further another wireless communication device 302. Suppose you want to communicate with.

[0079] In communication with the wireless communication device 302, as shown in FIG. 17, if communication is performed using antennas 101B and 101D that are not adjacent antennas, another wireless communication device 303 has antennas 101C and 101C. When trying to communicate the directional force of 101D, communication between the antenna 101D and the wireless communication device 302 is obstructed with respect to the antenna 101C that is not used (part of the radiation area overlaps, see arrows in the figure). As a result, communication with the wireless communication device 303 becomes impossible.

[0080] On the other hand, if a plurality of adjacent antennas are necessarily selected in step S135, step S140, and step S150, in the above example, the adjacent antenna 101B in communication with the wireless communication device 302 is used. , 101C, and as a result, communicate with the wireless communication device 303 using at least the antenna 101D (without disturbing other forces) It becomes possible. This is also effective when the communication partner moves.

[0081] (2) When combining MIMO with STC, SDM, OFDM, etc.

In the above embodiment, when control is performed so that MIMO communication is performed in step S150 in the flow shown in FIG. 10, a force that is not particularly described in detail will be described. A spatial coding scheme (STC) or a spatial division multiplexing scheme (S DM) may be used. It is also possible to combine known orthogonal frequency division multiplexing (OFDM) techniques as appropriate.

[0082] In the wireless communication device 1 according to the present modification, the communication system control unit S100 uses at least a shift between the communication system of a space-time coding system, a space division multiplexing system, and an orthogonal frequency division multiplexing system. It is characterized by controlling to a communication system that combines either of these.

[0083] As a result, the transmitted! /, Control for transmitting time-series data by recombining signals in the time domain and the space domain (= space-time coding scheme: STC), transmission antenna elements, etc. Control with transmission of different information with power (= space division multiplexing; SDM) and multi-carrier transmission control (= orthogonal frequency division multiplexing; with spread of wide frequency band information on multiple subchannels in narrow frequency band; (OFDM) etc. can be realized, and V 効率 communication can be performed reliably and efficiently with the communication partner.

[0084] The wireless communication device 1 in the above embodiment is a wireless communication device 1 that can be used for the wireless communication system S of the multiple-input multiple-output system, where m is an integer equal to or larger than 2, and a plurality of antenna elements P0 Step S5 for controlling each antenna so that the m antennas 101 each having ~ P6 and the directivity realized by all these m antennas 101 are in a predetermined initial state, and in this step S5 According to the initial communication content with the other wireless communication device 301 in the realized initial state, the procedure of step S100 for setting the communication condition in communication with the other wireless communication device 301 is included.

[0085] Before the start of communication, first, in step S5, the directivity of all the six antennas 101A to 101F is set to a predetermined initial state. Then, in accordance with the initial communication content that has been communicated with another wireless communication device 301 in this initial state, the communication conditions with the other wireless communication device 301 thereafter are set in step S100. This realizes a multi-input multi-output system Although it has possible performance, depending on the initial communication contents with other wireless communication device 301, it does not stick to the communication of the multi-input / multi-output method, and wireless communication is performed in a communication mode suitable for the other wireless communication device 301. Communication can be performed. As a result, it is possible to reliably realize efficient communication corresponding to various communication partners.

Brief Description of Drawings

FIG. 1 is a system configuration diagram illustrating an overall outline of a wireless communication system including a wireless communication apparatus according to an embodiment of the present invention.

2 is a perspective view showing a detailed structure of the antenna shown in FIG.

FIG. 3 is an explanatory diagram for explaining a control system of the antenna shown in FIGS. 1 and 2.

4 is a functional block diagram showing a detailed configuration of the control device shown in FIG. 1.

5 is a functional block diagram showing a detailed configuration of functions related to a transmission side in the configuration shown in FIG.

6 is a functional block diagram showing a detailed configuration of functions related to the receiving side in the configuration shown in FIG.

7 is a flowchart showing a control procedure executed by the overall control unit of the control device shown in FIG.

FIG. 8 is an explanatory view schematically showing a radio wave radiation mode in a standby state after initial setting.

FIG. 9 is a flowchart showing a detailed procedure of step S100.

FIG. 10 is an explanatory diagram schematically showing a communication mode with another wireless communication device.

FIG. 11 is an explanatory view schematically showing a communication mode with another wireless communication device.

FIG. 12 is a conceptual explanatory diagram conceptually showing the behavior of MIMO communication.

FIG. 13 is an explanatory view schematically showing a communication mode with still another wireless communication device.

FIG. 14 is a diagram showing an actual application example of a wireless communication device.

FIG. 15 is a diagram showing another application example of the wireless communication device.

FIG. 16 is a diagram schematically showing an image of directivity control characteristics by the non-feed side control means and the feed side control means.

FIG. 17 is a diagram showing a modification in which a plurality of adjacent antennas are selected. Explanation of symbols

1 Wireless communication device (wireless transmitter; wireless receiver)

101A ~ F Antenna

200 control unit

201 Overall control unit

301 wireless communication device

302 wireless communication equipment

303 wireless communication equipment

PO Feed antenna element (feed element, antenna element)

Pl ~ 6 Parasitic antenna element (parasitic element, antenna element) S Wireless communication system

Claims

The scope of the claims

[1] A wireless communication apparatus that can be used in a multiple-input multiple-output wireless communication system, where m is an integer of 2 or more, m antennas each having a plurality of antenna elements, and all these m antennas The initial control means for controlling each antenna so that the directivity realized in is in a predetermined initial state,

A communication condition control means for setting a communication condition in communication with the other wireless communication device in accordance with the initial communication content with the other wireless communication device in the initial state realized by the initial control means;

A wireless communication apparatus comprising:

[2] In the wireless communication device according to claim 1,

The communication condition control means includes communication method control means for controlling the communication method to be any one of the multi-input multi-output method, the adaptive array method, or the diversity method as the communication condition. A wireless communication device.

[3] The wireless communication device according to claim 2,

The communication system control means is characterized in that, when the other wireless communication apparatus includes an antenna composed of one antenna element, the communication system is an adaptive array system.

[4] The wireless communication device according to claim 2,

The communication method control means controls the communication method to a communication method that further combines at least one of a space-time coding method, a space division multiplexing method, and an orthogonal frequency division multiplexing method. Wireless communication device.

[5] The wireless communication device according to claim 1,

The wireless communication apparatus, wherein the communication condition control means includes antenna number control means for setting N as an integer of 1 to m and setting the number of antennas to be used as N as the communication condition.

[6] The wireless communication device according to claim 1,

The communication condition control means, based on the number of antennas set by the antenna number control means, as the communication condition, the plurality of keys for each of the remaining antennas. A wireless communication device comprising directivity control means for controlling directivity by an antenna element in a predetermined manner.

[7] The wireless communication device according to claim 1,

The communication condition control means includes a power supply control means for stopping power supply to other remaining antennas based on the number of antennas set by the antenna number control means as the communication condition. apparatus.

[8] The wireless communication device according to claim 1,

The plurality of antenna elements of the antenna are

A feeding element to which a signal is fed, and at least one parasitic element that is provided at a predetermined interval from the feeding element and is not fed with a signal,

Enclosed or loaded in a dielectric, and placed at predetermined intervals! A wireless communication device characterized in that it speaks.

[9] The wireless communication device according to claim 8,

The communication condition control means includes

As the communication condition, power supply side control means for controlling the directivity of the power supply element provided in the m antennas,

As the communication condition, a parasitic side control means for controlling the directivity of the parasitic element provided in the m antennas;

A wireless communication apparatus comprising:

[10] The wireless communication device according to claim 1,

The wireless communication apparatus, wherein the initial control means controls the antennas so that the directivities of adjacent antennas among m antennas partially overlap each other as the initial state.

[11] A wireless communication system comprising a wireless transmission device and a wireless reception device and capable of multi-input multiple-output communication,

At least one of the wireless transmitter and the wireless receiver is

When m is an integer of 2 or more, m antennas each having a plurality of antenna elements enclosed or loaded in a dielectric and arranged at predetermined intervals, Initial control means for controlling each antenna so that the directivity realized by all these m antennas becomes a predetermined initial state;

A wireless communication system comprising: