JP5032185B2 - Wireless communication system, wireless communication method, and communication apparatus - Google Patents

Description

The present invention relates to a radio communication system, radio communication method, relates 及 beauty communication device, in particular, the base station performs communication between a base station / mobile station allocates radio resources to the mobile station, the communication of the base station The present invention relates to an apparatus in which a plurality of communication devices exist in an area and perform communication between these communication devices.

  In recent years, an IEEE 802.16e standard wireless system that performs user access using the OFDMA scheme has begun to be put into practical use as a wireless system that uses a wide-band frequency wireless resource including a large number of subcarriers. In the OFDMA scheme, high-speed communication is realized by assigning a communication channel to a user (mobile station) in units of subcarriers or subchannels in which a plurality of subcarriers are bundled (see, for example, Patent Document 1).

On the other hand, for example, a wireless system such as a transceiver that performs narrow-band wireless communication that handles only voice is also conventionally used.
JP 2000-188583 A

  In mobile communication systems such as the OFDMA system described above, a communication area called a cell is formed around a base station, and the base station communicates with mobile stations existing in the cell. In general, there are communication devices that communicate with other communication methods in the cell, such as the above-mentioned transceivers. In order to prevent interference between stations or devices of different methods, there are laws and regulations. Usable radio frequencies are assigned, and each communication method performs communication using the determined frequency band.

  Conventionally, interference was prevented by strictly managing the radio frequency in this way. For this reason, for example, it has been impossible to realize a frequency utilization method in which a transceiver performs communication using (a part of) a frequency band used in the OFDMA scheme. Further, as a result, it has not been possible to sufficiently achieve efficient use of limited frequency resources.

The present invention has been made in view of the above points, and an object of the present invention is to provide a radio system in which a base station and a mobile station perform communication using radio resources having a broadband frequency, and a frequency narrower than that of the radio system. a wireless system communicate with each other is a communication device that uses is capable wireless communication systems coexist using the radio resources of the same frequency, wireless communication method, is to provide a 及 beauty communication device.

The present invention has been made to solve the above-described problems, and divides a radio resource having a predetermined frequency width and a predetermined time length and assigns it to a mobile station as a communication channel, and communicates with the mobile station and the allocated communication. A radio communication system including a base station that communicates using a channel, the mobile station, and a plurality of communication devices that communicate with each other using a part of the radio resource, wherein the base station Channel allocation means is provided for allocating the communication channel to a portion of the radio resource excluding reserved radio resources consisting of a predetermined frequency band and time domain, and the communication device is self-indicating the location of the communication device. position information acquisition means for acquiring the device location information, only the reserved radio resources in the time domain and the transmission control means for controlling transmission timing to communicate Wherein the transmission control means includes a time information indicating the time domain of the reserved radio resources, the base station position information indicating the location of the base station, and the own device location information acquired by the position information acquiring means the calculated radio wave arrival required time from the base station, characterized that you control the transmission timing based on the arrival required time to the time information the calculated on the basis of.

The present invention also divides a radio resource having a predetermined frequency width and a predetermined time length and assigns it to a mobile station as a communication channel, and communicates with the mobile station using the assigned communication channel, and the mobile A wireless communication method in a wireless communication system including a station and a plurality of communication devices that communicate with each other by using a part of the wireless resource, from a predetermined frequency band and time domain of the wireless resource A channel allocating step for allocating the communication channel to a portion excluding reserved radio resources, a position information acquiring step for acquiring the own device position information indicating a location of the communication device, and the reserved radio resources A transmission control step for controlling the transmission timing of the communication device so as to perform communication only in the time domain of In the control step, based on the time information indicating the time domain of the reserved radio resource, the base station position information indicating the location of the base station, and the own device position information acquired in the position information acquisition step A time required for arrival of radio waves from the base station apparatus is calculated, and transmission timing is controlled based on the calculated time required for arrival and the time information .

The present invention also provides a base station that communicates with a mobile station using a communication channel that is a portion of a radio resource having a predetermined frequency width and a predetermined time length, excluding reserved radio resources consisting of a predetermined frequency band and time domain. A communication device that communicates with each other within a communication area, and communicates with location information acquisition means that acquires location information indicating the location of the communication device only within the time domain of the reserved radio resource. Transmission control means for controlling the transmission timing as described above, wherein the transmission control means includes time information indicating a time region of the reserved radio resource, base station position information indicating a location of the base station, and the position Based on the own device position information acquired by the information acquisition means, the time required to reach the radio wave from the base station is calculated, and the calculated time required for the arrival and the time And controlling the transmission timing on the basis of the information.

  According to the present invention, the communication apparatus controls the transmission timing and performs communication within the time domain of the reserved radio resource, and the base station and the mobile station perform communication by assigning a communication channel to the radio resource excluding the reserved radio resource. Therefore, the base station, the mobile station, and the communication device can coexist using the same radio resource.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a configuration diagram as an embodiment of a wireless communication system to which the present invention is applied. In this wireless communication system, the base station 10 communicates with the mobile station 20 by an OFDMA (Orthogonal Frequency Division Multiple Access) method. There are three mobile stations 20 in a cell that is a communication area in which communication with the base station 10 is possible, and a one-to-many P-MP (between the base station 10 and the three mobile stations 20 by OFDMA communication). Point to Multipoint connection is realized.

  In addition, in the cell of the base station 10, there are two communication devices 30 that use a communication method other than the OFDMA method. These communication devices 30 are transceivers that perform one-to-one communication, for example, and communicate with each other only between the communication devices 30 without being connected to the base station 10 or the mobile station 20. Here, as will be described below, the communication method used by the communication device 30 has a narrower frequency bandwidth than the frequency bandwidth of the communication method (OFDMA method) used between the base station and the mobile station. Suppose that

  FIG. 2 is a diagram showing a configuration (channel allocation) of radio resources used by the base station 10 and the mobile station 20 in FIG. 1 in OFDMA communication. The radio resource is an area where communication data is arranged, characterized by frequency and time. In FIG. 2, one unit of radio resources has a frequency width BW in the frequency direction and a time length T0 (= 1 time slot) in the time direction.

  In the OFDMA scheme, a large number of subcarriers that are carrier waves for carrying communication data are provided in the frequency width BW, and radio resources are allocated to the mobile station 20 in units of subchannels in which a plurality of subcarriers are collected. The radio resource configuration of FIG. 2 is a case where a TDD (Time Division Duplex) system is applied as a duplex system, and one time slot is a downlink DL (Downlink) and an uplink UL ( Downlink (Uplink) is performed, and downlink (from the base station 10 to the mobile station 20) and uplink (from the mobile station 20 to the base station 10) using the same frequency band are performed.

  In the downlink DL, a preamble that is a signal for the mobile station 20 to find the presence of the base station 10 and the timing of the time slot is arranged at the beginning of the time slot. Behind the preamble are DL-MAP, which is information indicating channel assignment to each mobile station 20 in the downlink DL, and UL-MAP, which is information indicating channel assignment to each mobile station 20 in the uplink UL. Is placed. Further, a communication channel assigned to each mobile station 20 according to DL-MAP is further provided, and transmission data to the mobile station is arranged in the communication channel of each mobile station 20.

  In addition, in the uplink UL, a communication channel assigned to each mobile station 20 according to UL-MAP is provided, and each mobile station 20 arranges transmission data in this communication channel and transmits it to the base station 10.

  Here, in FIG. 2, the allocation of communication channels to the mobile stations 20 in the downlink DL and the uplink UL is performed excluding the frequency band used for communication by the communication device 30 in the entire frequency width BW of the radio resource. . The frequency band used for communication by the communication device 30 is a portion indicated as a reserved radio resource in FIG. 2, and has a frequency width BW1 (where BW1 <BW). For example, in general, in the OFDMA system, the frequency width BW of radio resources is about several MHz, and the frequency bandwidth BW1 used by the communication device 30 such as a transceiver is about several kHz to several tens of kHz.

  On the other hand, the communication device 30 performs communication using reserved radio resources. Here, since the preamble and DL-MAP / UL-MAP transmitted by the base station 10 occupy the entire frequency band BW of the radio resource, the reserved radio resource includes the preamble and DL-MAP / UL in the time direction. -It has an area excluding MAP. Therefore, the communication device 30 performs communication using only reserved radio resources by controlling the data transmission timing so that communication is not performed during the preamble and DL-MAP / UL-MAP time zones.

  In this way, the base station 10 and the mobile station 20 perform communication by allocating the communication channel to the part of the radio resource excluding the reserved radio resource, and the communication device 30 performs the reserved radio that is a part of the radio resource. By performing communication using resources, wireless systems using different communication methods can share the same wireless resource and coexist. And since the communication apparatus 30 does not communicate in the time zone of a preamble and DL-MAP / UL-MAP by controlling transmission timing, even if the communication apparatus 30 exists in the cell of the base station 10, it moves. The station 20 can correctly receive the preamble and the DL-MAP / UL-MAP without receiving interference from the communication device 30.

FIG. 3 is a block diagram illustrating a configuration of a transmitter included in the base station 10.
The transmitter of the base station 10 includes a data control unit 101, a channel allocation unit 102, a modulation unit 103, an S / P conversion unit 104, an IFFT unit 105, a GT addition unit 106, a radio unit 107, an antenna, 108.

  In FIG. 3, transmission data addressed to each mobile station 20 is input to the data control unit 101. The data control unit 101 arranges the input transmission data in the communication channel assigned to each mobile station 20 in accordance with the instruction from the channel assignment unit 102 and outputs it to the modulation unit 103.

  The channel allocation unit 102 receives the scheduling information, divides the radio resource according to the scheduling information, allocates it to each mobile station 20 as a communication channel, and instructs the data control unit 101 on the allocation result. The scheduling information is information that determines which communication channel is allocated to which mobile station 20 in accordance with, for example, an allocation request from the mobile station 20, a propagation state of a wireless communication path, a communication data capacity, and the like. The scheduling information also includes information about which frequency band of the radio resources used by the base station 10 can be used by the communication device 30. Using these pieces of information, the channel assignment unit 102 determines a reserved radio resource and assigns the communication channel of each mobile station 20 to a portion of the radio resource excluding the reserved radio resource.

  The modulation unit 103 appropriately modifies the transmission data input from the data control unit 101, such as QPSK (Quadrature Phase Shift Keying), 16QAM (Quadrature Amplitude Modulation), and 64QAM. The data is modulated by a predetermined method, and the modulated data is output to the S / P converter 104.

The S / P (Serial / Parallel) conversion unit 104 performs serial / parallel conversion on the input modulation data, arranges the data in the arrangement order corresponding to the sub-channels of the radio resources, and outputs the data to the IFFT unit 105 To do.
An IFFT (Inverse Fast Fourier Transform) unit 105 converts the data in the order of arrangement corresponding to the subchannels into a signal in the time domain by IFFT processing, and outputs the signal to the GT adding unit 106.
A GT (Guard Time) adding unit 106 adds a guard time to the transmission data by copying a predetermined length portion of the input data to the end of the data, and outputs the transmission data to the radio unit 107.
The radio unit 107 modulates the input transmission data with a radio frequency, and transmits the modulated radio signal from the antenna 108 to each mobile station 20.

  With such a configuration and the function of each unit, transmission data from the base station 10 to the mobile station 20 is mapped to the downlink DL communication channel and transmitted. The mapped transmission data is present in a part of the radio resources excluding reserved radio resources, and communication channels are allocated so that no transmission data exists in the reserved radio resources.

  Note that the base station 10 transmits the preamble and DL-MAP / UL-MAP to the mobile station 20 using the entire frequency band BW of the radio resource. By doing so, the mobile station 20 can receive the preamble and DL-MAP / UL-MAP as control information in any subchannel in the radio resource. As a result, the reserved radio resource can be dynamically changed. For example, when the communication device 30 does not exist in the cell of the base station 10, all the radio resources are used for base station / mobile station communication without providing reserved radio resources, and the communication device 30 If the wireless resource exists, a reserved radio resource having a size necessary for communication between the communication devices 30 can be provided.

  4 to 6 are block diagrams showing the configuration of the communication device 30, and show three embodiments of the communication device 30 each having a different configuration.

The communication device 30 according to the embodiment of FIG. 4 includes a transmission control unit 301, a modem unit 302, a radio unit 303, an antenna 304, and a transmission timing determination unit 305.
In the figure, transmission data addressed to the communication device 30 which is a communication partner is input to the transmission control unit 301. The transmission control unit 301 outputs the input transmission data to the modem unit 302 at the transmission timing instructed from the transmission timing determination unit 305. The transmission data is modulated by the modulation / demodulation unit 302 using a predetermined modulation method, then modulated by the radio unit 303 at a radio frequency, and transmitted from the antenna 304 to the communication apparatus 30 as a communication partner. Further, data transmitted from the communication apparatus 30 as a communication partner is received by the antenna 304, demodulated by the radio unit 303 and the modem unit 302, and acquired as received data.

The transmission timing determination unit 305 determines the transmission timing so as not to perform communication in the time zone of the preamble and DL-MAP / UL-MAP that are control information in one time slot, and determines to the transmission control unit 301 Instruct the transmission timing. For this processing, the communication device 30 holds information on the start time and end time of the reserved radio resource, and the transmission timing determination unit 305 determines the above transmission timing based on these time information. The time information includes a preamble transmission start time t _i (i indicates that it is the i-th time slot) in the base station 10 and a transmission slot of control information (preamble and DL-MAP / UL-MAP). The same is true if the length T1 is held.

Here, the start time t _i + T1 and the end time t _{i + 1} of the reserved radio resources held by the communication device 30 are based on the time at the base station 10. Therefore, at the position of the communication device 30 that is located at a certain distance from the base station 10, the end time of the control information, that is, the start time t _i + T1 of the reserved radio resource, or the start time of the control information, that is, the reservation. The end time t _{i + 1} of the completed radio resource is delayed in time by the time required for the radio wave emitted from the base station 10 to reach the position of the communication device 30. This time depends on the distance between the base station 10 and the communication device 30. In view of this, it is preferable that the transmission timing determination unit 305 determines, for example, the time from the time t _i + T1 + α to the time t _{i + 1} + β as the transmission timing, and instructs the transmission control unit 301 to determine the time. It is. Accordingly, by setting α and β to appropriate values, it is possible to prevent the control information from the base station 10 and the transmission data from the communication device 30 from interfering with each other in the mobile station 20 in the cell.

  Next, the communication device 30 according to the embodiment of FIG. 5 includes a transmission control unit 301, a modem unit 302, a radio unit 303, an antenna 304, a transmission timing determination unit 305, a position information acquisition unit 306, and a GPS antenna. 307. In this communication apparatus 30, the configurations and functions of the transmission control unit 301, the modem unit 302, the radio unit 303, and the antenna 304 are the same as those in FIG.

  The position information acquisition unit 306 acquires position information (latitude and longitude) indicating the location of the communication device 30 based on a GPS signal from a GPS satellite received by a GPS (Global Positioning System) antenna 307, and determines transmission timing. The acquired position information is output to the unit 305. Note that the GPS signal can also be used for highly accurate time adjustment, whereby the communication device 30 synchronizes the time with the base station 10.

  Similarly to the case of FIG. 4, the transmission timing determination unit 305 determines the transmission timing so that communication is not performed in the time zone of the preamble and DL-MAP / UL-MAP as control information in one time slot. The transmission control unit 301 is instructed to determine the transmission timing. For this processing, the communication device 30 uses position information (latitude and longitude) indicating the location of the base station 10 and information on the start time and end time of reserved radio resources (based on the time at the base station 10). ) And hold.

  Then, the transmission timing determination unit 305 calculates the time required for the radio wave emitted from the base station 10 to reach the position of the communication device 30 based on the position information of the base station 10 and the position information of the communication device 30. To do. Further, the transmission timing determination unit 305 adds the calculated arrival time of the radio wave to the start time and end time of the reserved radio resource, and sets the time from the start time to the end time after the addition as the above transmission timing. decide. The transmission timing determination unit 305 instructs the transmission control unit 301 to determine the transmission timing thus determined.

  By determining the transmission timing as described above, the start and end times of the actual reserved radio resources at the position of the communication device 30 (the control information transmitted after the control information transmitted from the base station 10 is no longer received) The time difference until the start of reception is the time domain of the actual reserved radio resource) is delayed with respect to the start / end time (base station 10 reference) held by the communication device 30. It is possible to correct it. Further, the correction of the time lag can be accurately performed regardless of the position of the communication device 30. As a result, it is ensured that the communication device 30 does not communicate during the control information transmission time zone, so that the control information from the base station 10 and the transmission data from the communication device 30 are stored in the cell. It is possible to improve the accuracy of control that prevents interference in the mobile station 20.

  Next, the communication device 30 according to the embodiment of FIG. 6 includes a transmission control unit 301, a modem unit 302, a radio unit 303, an antenna 304, and a transmission timing determination unit 305. In this communication apparatus 30, since some of the functions of the above-described units are the same as those in FIG. 4, description thereof will be omitted, and only functions different from those in FIG. 4 will be described.

  The modem unit 302 detects the head of the preamble transmitted from the base station 10 on the downlink DL, and outputs a signal indicating the head timing to the transmission timing determination unit 305. The transmission timing determination unit 305 stops receiving control information based on the signal indicating the timing of the beginning of the preamble and the information of the transmission slot length T1 (constant value) of the control information held by the communication device 30. Calculate the time. Then, the transmission timing determination unit 305 determines the time from the calculated time to the time when the head of the next preamble is detected as the transmission timing, and instructs the transmission control unit 301 to perform the instruction.

  By determining the transmission timing in this way, the transmission timing is accurately determined according to the actual signal from the base station 10, and the control information from the base station 10 and the transmission data from the communication device 30 are transmitted to the mobile station 20 in the cell. Can be prevented from interfering with each other. Further, since the actual signal from the base station 10 is used, the transmission timing can be accurately determined regardless of the position of the communication device 30.

  As described above, the embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to the above, and various design changes and the like can be made without departing from the scope of the present invention. It is possible to

  For example, the radio resource configuration shown in FIG. 2 is an example to which the present invention is applied, and can be changed as appropriate. Specifically, the reserved radio resource may be arranged anywhere within the frequency width BW of the radio resource. Further, when there are a large number of communication devices, the reserved radio resources may be widened accordingly. At this time, the reserved radio resources may not be combined into one, but may be arranged as a plurality of reserved radio resources in a discrete manner (frequency direction) in the radio resource.

It is a block diagram as one Embodiment of the radio | wireless communications system to which this invention was applied. FIG. 2 is a diagram illustrating a configuration of radio resources used by the base station and the mobile station in FIG. 1 in OFDMA communication. It is a block diagram which shows the structure of the transmitter with which a base station is provided. It is a block diagram which shows the structure of a communication apparatus. It is a block diagram which shows the structure of the communication apparatus which concerns on another embodiment. It is a block diagram which shows the structure of the communication apparatus which concerns on another embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Base station 20 ... Mobile station 30 ... Communication apparatus 101 ... Data control part 102 ... Channel allocation part 103 ... Modulation part 104 ... S / P conversion part 105 ... IFFT part 106 ... GT addition part 107 ... Radio | wireless part 108 ... Antenna 301 ... Transmission control unit 302 ... Modulation / demodulation unit 303 ... Radio unit 304 ... Antenna 305 ... Transmission timing determination unit 306 ... Position information acquisition unit 307 ... GPS antenna

Claims (3)

A radio resource having a predetermined frequency width and a predetermined time length is divided and allocated to a mobile station as a communication channel, a base station that communicates with the mobile station using the allocated communication channel, the mobile station, and the radio A wireless communication system including a plurality of communication devices that communicate with each other using a part of resources,
The base station comprises channel allocation means for allocating the communication channel to a portion of the radio resource excluding reserved radio resources composed of a predetermined frequency band and time domain,
The communication apparatus includes position information acquisition means for acquiring own apparatus position information indicating a location of the communication apparatus , and transmission control means for controlling transmission timing so as to perform communication only within the time domain of the reserved radio resource. It equipped with a door,
The transmission control means is based on time information indicating a time region of the reserved radio resource, base station position information indicating a location of the base station, and own apparatus position information acquired by the position information acquisition means. A wireless communication system characterized in that a time required for arrival of radio waves from the base station is calculated and transmission timing is controlled based on the calculated time required for arrival and the time information . A radio resource having a predetermined frequency width and a predetermined time length is divided and allocated to a mobile station as a communication channel, a base station that communicates with the mobile station using the allocated communication channel, the mobile station, and the radio A wireless communication method in a wireless communication system including a plurality of communication devices that communicate with each other using a part of resources,
A channel allocating step for allocating the communication channel to a portion excluding reserved radio resources consisting of a predetermined frequency band and a time domain among the radio resources ;
A position information acquisition step in which the communication apparatus acquires own apparatus position information indicating a location of the communication apparatus;
A transmission control step of controlling the transmission timing of the communication device so as to perform communication only within the time domain of the reserved radio resource;
Have
In the transmission control step, based on time information indicating a time region of the reserved radio resource, base station position information indicating a location of the base station, and own device position information acquired in the position information acquisition step. A radio communication method characterized by calculating a required arrival time of radio waves from the base station apparatus and controlling transmission timing based on the calculated required arrival time and the time information . Within a communication area of a base station that communicates with a mobile station using a portion of a radio resource having a predetermined frequency width and a predetermined time length, excluding reserved radio resources consisting of a predetermined frequency band and time domain, as a communication channel A communication device for communicating with
Position information acquisition means for acquiring own apparatus position information indicating a location of the communication apparatus;
And a transmission control means for controlling transmission timing to communicate only in the time domain of the reserved radio resources,
The transmission control means is based on time information indicating a time region of the reserved radio resource, base station position information indicating a location of the base station, and own apparatus position information acquired by the position information acquisition means. A communication apparatus that calculates a required arrival time of radio waves from the base station and controls transmission timing based on the calculated required arrival time and the time information .

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