GB2466161A

GB2466161A - Method for designating random-access signal, method for communicating random-access-signal, and base station device using the same methods

Info

Publication number: GB2466161A
Application number: GB1006082A
Authority: GB
Inventors: Yoichi Matsumoto; Atsushi Fujiwara
Original assignee: Arraycomm LLC
Current assignee: Arraycomm LLC
Priority date: 2007-09-07
Filing date: 2007-10-24
Publication date: 2010-06-16
Anticipated expiration: 2027-10-24
Also published as: GB201006082D0; JP5140352B2; WO2009031186A1; CN101983482B; DE112007003649T5; GB2466161B; CN101983482A; JP2009065509A

Abstract

A controller section (26) generates at least two control signals for designating a burst for transmission of a random-access signal to a terminal device in a single down-subframe. A baseband processing section (24) and the like allocate each of at least two control signals to a burst different one another in the down-subframe for transmission. The baseband processing section (24) and the like receive the random-access signal from the terminal device in the burst designated for each of at least two control signals and in the burst in an up-subframe corresponding one-to-one to the burst with each control signal allocated. In a corresponding combination of the burst with the control signal allocated and the burst with the random-access signal allocated, control of the antenna directivity is shared in common.

Description

SPECIFICATION

METHOD FOR DESIGNATING RANDOM ACCESS SIGNALS, METHOD FOR COMMUNICATING RANDOM ACCESS SIGNALS, AND BASE STATION DEVICE

USING THE SAME

TECHNICAL FIELD

(0001) The present invention relates to communication technology; more particularly, it relates to a designation method and a communication method for random access signals for connecting to terminal devices and a base station device using the same.

BACKGROUND ART

(0002) One type of wireless communication system is a wireless MAN (Metropolitan Area Network) system which is standardized according to the IEEE 802.16 standard and the IEEE 802.16e standard (these are collectively called the "IEEE 802.16 standard" hereinafter). The physical layers prescribed by the IEEE 802.16 standard are SC (Single Carrier), OFDM (Or-thogonal Frequency Division Multiplexing), and OFDMA (Orthogonal Frequency Division Multiple Access). For example, the combination of TDMA and TDD has been investigated for OFDMA. The basic frame structure in this case consists of a downlink subframe, a TTG (Transmit/Receive Transmission Gap), an uplink subframe, and an RTG (Receive/Transmit Transmission Gap) (for example, see non-patent document 1).

Non-patent Document 1: YOKAI, Toshikazu, "IEEE 802.16 standards: 802.16-2004 (fixed WiMAX) and 802.16e (mobile WiMAX)", Wireless Broadband Textbook/High-Speed IP Wireless (ed.), Japan, Impress R&D, June 21, 2006, p. 159-212

DISCLOSURE OF THE INVENTION

PROBLEM TO BE SOLVED BY THE INVENTION

(0003) A signal for establishing data communication (called a "control signal" hereinafter) is provided at the beginning of the downlink subframe. The control signal contains an FCH (Frame Control Header), a DL-MAP (Downlink Map Message), and a UL-MAP (IJplink MAP Message), the details of which will be described below. Before communication between the base station device and a terminal device is begun, the terminal device transmits a signal to serve as an opportunity to begin communication-a ranging request signal, for example- based on the control signal sent from the base station device. This process is similarly per-formed at the time of handover. On the other hand, while communication is conducted between the base station device and the terminal device, the terminal device can understand the status of data signals allocated to it based on the control signal sent from the base station device. There- fore, the control signal can be considered an important piece of information not only for initiat-ing communication, but also for maintaining communication.

(0004) While communication is conducted between the base station device and the terminal device, the base station device allocates bursts to the terminal device. In other words, unicast communication is executed between the base station device and the terminal device using bursts. When unicast communication is performed, the base station device can control the an-tenna directivity so that the antenna faces the terminal device in question, which improves the reception properties at the terminal device. However, in the case of broadcast communication, such as the control signal, the base station device needs to adjust the antenna directivity so that the antenna faces multiple terminal devices, so the antenna directivity cannot be controlled. As a result, although the communication reception properties improve, the reception properties for the control signal, which represents information that is more important than the communication itself, do not improve. Therefore, if there is an imbalance in the communication quality be-tween unicast and broadcast communication, the reception properties of the communication system are controlled by the reception properties for broadcast communication, regardless of any improvement in the reception properties for unicast communication.

(0005) The present invention was conceived in light of such circumstances, and its purpose is to provide communication technology which reduces the effects of imbalances in the communica-tion quality between unicast and broadcast communication.

MEANS FOR SOLVING THE PROBLEM

(0006) In order to resolve the problem described above, the base station device of one mode of the present invention defines a frame formed from a downlink subframe containing multiple bursts and an uplink subframe containing multiple burst, equipped with a generation part which gen-erates at least two control signals for designating bursts which transmit random access signals to a terminal device in a single downlink subframe, a transmission part which allocates each of the at least two control signals generated by the generation part to bursts which differ from one another in the downlink subframe and transmits them, a reception part which receives the ran-dom access signals from the terminal device in bursts designated for each of the at least two control signals transmitted from the transmission part, which are bursts in an uplink subframe with a one-to-one correspondence to the bursts to which each control signal is allocated, and a controller part which controls the operation of the reception part and the transmission part. The controller part makes the directivity control of the antenna the same for combinations of corre- sponding bursts to which control signals are allocated and bursts to which random access sig-nals are allocated.

(0007) In this mode, the directivity control of the antenna is made to be the same for each combination by generating multiple combinations corresponding to control signals and random access signals, so the directivity of the antenna can be controlled in the same way for both up-linking and downlinking, even in broadcast communication.

(0008) The transmission part may be provided with bursts to which each control signal is allocated in the downlink subframe so that they are symmetrical with the arrangement of the bursts to which each random access signal is allocated in the uplink subframe. In this case, the arrange- ments of bursts for control signals and access signals are made to be the same, so the transmis-sion of information related to the allocation of random access signals can be omitted.

(0009) A measurement part for measuring the propagation environment may also be provided.

The transmission part may determine the arrangement of the bursts to which each control sig-nal is allocated based on the results of measurement by the measurement part. In this case, each control signal is allocated based on the propagation environment, so each control signal can be allocated in a manner suited to the propagation environment.

(0010) The transmission part provides a control signal to the burst at the beginning of the downlink subframe, and the transmission frequency of control signals other than the control signal provided to the burst at the beginning of the downlink subframe may be adjusted based on the status of the reception of random access signals by the reception part. In this case, the transmission frequency of control signals is adjusted based on the reception status of random access signals, so decreases in transmission efficiency can be suppressed.

(0011) Another mode of the present invention is a base station device. This device is a base station device which defines a frame containing multiple bursts, equipped with a generation part which generates a first control signal and multiple second control signals and a transmission part which provides the first control signal generated by the generation part to the burst at the beginning of the frame and provides the multiple second control signals to bursts which differ from one another and transmits them. The generation part includes at least part of the informa-tion of the first control signal in each of the multiple second control signals.

(0012) In this mode, at least part of the information of the first control signal is included in each of the multiple second control signals, so the quality of broadcast communication can be im-proved due to the presence of the first control signal and multiple second control signals.

(0013) Yet another mode of the present invention is a base station device. This device is a base station device which repeatedly defines frames containing multiple bursts, equipped with a generation part which generates a first control signal and multiple second control signals and a transmission part which provides the first control signal generated by the generation part to the burst at the beginning of the frame and provides the multiple second control signals to bursts which differ from one another and transmits them. The generation part includes information related to the frame where the first control signal is provided in the first control signal and in- cludes information related to frames following the frame where the first control signal is pro-vided in each of the multiple second control signals.

(0014) In this mode, information related to frames following the frame where the first control signal is provided is included in each of the multiple second control signals, so the degree of freedom in the arrangement of bursts to which the multiple second control signals are allocated can be improved.

(0015) A controller part for controlling the operation of the transmission part may also be provided. The controller part may make the antenna directivity control different for each of the multiple second control signals. In this case, the quality of broadcast transmission can be improved since the antenna directivity control is made to be different for each of the multiple second control signals.

(0016) Yet another mode of the present invention is a designation method for random access signals. This method comprises a step in which a frame formed from a downlink subframe containing multiple bursts and an uplink subframe containing multiple bursts is defined and at least two control signals for designating bursts which transmit random access signals to a ter- minal device are generated in a single downlink subframe, a step in which the at least two con-trol signals that are generated are allocated to bursts which differ from one another in the downlink subframe and are transmitted, and a step in which the random access signals from the terminal device are received in bursts designated for each of the at least two control signals that are transmitted, which are bursts in an uplink frame with a one-to-one correspondence to the bursts to which each control signal is allocated. In the transmission step and the reception step, the directivity control of the antenna is made to be the same for combinations of corre- sponding bursts to which control signals are allocated and bursts to which random access sig-nals are allocated.

(0017) Another mode of the present invention is a communication method. This method comprises a step in which a first control signal and multiple second control signals are gener-ated and a step in which, after a frame containing multiple bursts is defined, the generated first control signal is provided to the burst at the beginning of the frame, and the multiple second control signals are provided to bursts which differ from one another and are transmitted. In the generation step, at least part of the information of the first control signal is included in each of the multiple second control signals.

(0018) Yet another mode of the present invention is a communication method. This method comprises a step in which a first control signal and multiple second control signals are gener-ated and a step in which, after frames containing multiple bursts are repeatedly defined, the generated first control signal is provided to the burst at the beginning of the frame, and the multiple second control signals are provided to bursts which differ from one another and are transmitted. In the generation step, information related to the frame where the first control sig-nal is provided is included in the first control signal, and information related to frames following the frame where the first control signal is provided in each of the multiple second control signals.

(0019) The arbitrary combinations of the components described above and the expressions of the present invention can be changed between terms such as "method," "device," "system," "me-dium," and "computer program" as additional effective modes of the present invention.

EFFECT OF THE INVENTION

(0020) With the present invention, the effects of imbalances in the communication quality between unicast and broadcast communication can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

(0021) (FIG. 1) shows the configuration of the communication system of an embodiment of the present invention.

(FIG. 2) FIG. 2 (a)-(b) shows the frame format of a communication system used as a compari-son to the communication system of FIG. 1.

(FIG. 3) is a sequence diagram showing the network entry procedure of the communication system of FIG. 1.

(FIG. 4) shows the configuration of the base station device of FIG. 1.

(FIG. 5) FIG. 5 (a)-(b) shows the frame format of the base station device of FIG. 1.

(FIG. 6) FIG. 6 (a)-(c) shows the antenna directivity generated by the controller part of FIG. 1.

(FIG. 7) shows the configuration of the terminal device of FIG. 1.

(FIG. 8) is a flowchart showing the network entry procedure of the base station device of FIG. 4.

(FIG. 9) is a flowchart showing the network entry procedure of the terminal device of FIG. 7.

(FIG. 10) shows the data structure of the table stored by the controller part in a variation of the present invention.

(FIG. 11) is a flowchart showing the procedure for changing the transmission frequency with the base station device in a variation of the present invention.

(FIG. 12) shows the frame format of another variation of the present invention.

(FIG. 13) shows the frame format of yet another variation of the present invention.

(FIG. 14) is a flowchart showing the DL-MAP transmission procedure of the base station de-vice in yet another variation of the present invention.

(FIG. 15) is a flowchart showing the DL-MAP transmission procedure of a terminal device in yet another variation of the present invention.

EXPLANATION OF REFERENCES

(0022) 10 base station device, 12 terminal device, 20 antenna, 22 RF part, 24 baseband processing part, 26 controller part, 30 antenna, 32 RF part, 34 baseband processing part, 36 controller part, communication system.

BEST MODE FOR CARRYING OUT THE INVENTION

(0023) An overview of the present invention will be given before it is described in detail. An embodiment of the present invention relates to a communication system which performs TDMA in the time direction while performing OFDMA in the frequency direction, as pre-scribed by the IEEE 802.16 standard. A base station device defines a frame based on downlink and uplink subframes and provides a control signal to the beginning of the downlink subframe while providing a ranging region to the uplink subframe. A terminal device obtains parameters when it receives the control signal sent from the base station device. The terminal device transmits ranging requests as random access signals in the ranging region while using the ob-tained parameter data. Processing for network entry is then performed between the base station device and the terminal device, and communication is established between both devices. On the other hand, terminal devices which are incapable of receiving control signals sent from the base station device cannot transmit ranging requests, so they cannot communicate with the base station device. In order to accommodate such cases, the base station device in this em-bodiment performs the following processing.

(0024) The base station device generates a signal (called a "D signal" hereinafter) containing at least part of the information contained in the control signal. The base station device sends multiple D signals while changing the antenna directivity in the downlink subframe. On the other hand, the base station device provides bursts to each of multiple random access signals (called "R signals" hereinafter) in the uplink subframe so that they are symmetrical with the arrangement of the bursts to which D signals are allocated in the downlink subframe. Here, the function of the R signals is the same as that of a ranging request. The base station device makes the antenna directivity the same for the corresponding D signals and R signals. The ter-minal signal [sic] is able to receive any of the D signals even if it cannot receive control signals.

For example, a D signal transmitted with antenna directivity in the direction of the location of the terminal device in question is easily received by this terminal device. The terminal device transmits an R signal in a burst corresponding to the received D signal. Since the antenna di-rectivity is the same for bursts of D signals and bursts of R signals, the R signal transmitted from the terminal device is easily received by the base station device.

(0025) FIG. 1 shows the configuration of a communication system 100 of an embodiment of the present invention. The communication system 100 comprises a base station device 10 and first and second terminal devices 12a and 12b, which are collectively called terminal devices 12.

Here, one base station device 10 and two terminal devices 12 are shown, but the numbers of base station devices 10 and terminal devices 12 are not limited to this configuration.

(0026) The base station device 10 defines a frame formed from a downlink subframe containing multiple bursts and an uplink subframe containing multiple bursts. The details of the frame configuration will be described below, but the frames are provided repeatedly. The base station device 10 communicates with the terminal devices 12 by allocating bursts contained in the downlink and uplink subframes to the terminal devices 12. Here, the operation for allocating bursts to new terminal devices 12 is called network entry processing.

(0027) If multiple base station devices 10, which are not shown in the figure, are installed, the terminal devices 12 perform handover processing with the multiple base station devices 10.

The operation in which the base station device 10 of a handover destination allocates bursts to new terminal devices 12 is also called network entry processing. Each base station device 10 may be equipped with multiple antennas, but only one antenna is shown here in order to simplify the drawing. The terminal devices 12 communicate with the base station device 10 with the bursts allocated by the base station device 10.

(0028) FIG. 2 (a)-(b) shows the frame format of a communication system used as a comparison to the communication system 100. The vertical axis in FIG. 2 (a) corresponds to frequency, and the horizontal axis corresponds to time. As described above, OFDMA is used, so the frequency shown in the vertical axis corresponds to the subcarrier frequency. As shown in FIG. 2 (a), one frame is formed from a downlink subframe, a TTG, an uplink subframe, and an RTG. The downlink subframe is begun with a preamble-in other words, a known signal. An FCH is pro-vided after the preamble. The FCH contains a DLFP (Downlink Frame Prefix), the MCS (Modulation and Coding Scheme) level of the DL-MAP, and the length of the DL-MAP as profile information.

(0029) The DL-MAP contains position information and mapping information such as the modulation formula for each downlink burst contained in the downlink subframe in question.

Here, a burst is a data region specified by a combination of the frequency and time and is the unit used for the zones allocated to the terminal devices 12 and the like. Therefore, the position information of a downlink burst is indicated by a combination of the frequency and time. The UL-MAP contains position information and mapping information such as the modulation for-mula for each uplink burst contained in the uplink subframe in question. Multiple downlink bursts are included in the downlink subframe after these pieces of information. The arrange-ment of the multiple downlink bursts is determined in accordance with the DL-MAP.

(0030) Each downlink burst is allocated to a terminal device 12, and unicast communication is thereby realized from the base station device 10 to the terminal devices 12. Control signals such as notification signals may also be allocated to the downlink bursts. In this case, broadcast communication is realized from the base station device 10 with the downlink bursts. Like the downlink subframe, the uplink subframe also contains multiple uplink bursts. Also provided is a ranging region, where the terminal devices 12 transmit ranging requests to the base station device 10.

(0031) FIG. 2 (b) shows the configuration of a frame, as in FIG. 2 (a). Here, the configuration of a frame is shown for a case in which the base station device 10 corresponds to an AAS (Adap-tive Array Antenna System). In an AAS, by dispatching transmission signals with respectively weighted phases and amplitudes to multiple physically separated antennas, transmission waves emitted from each antenna are combined in space on the radiating surface, and regions with strong and weak electrical field distributions are formed in specific directions. The base station device 10 executes AAS processing in the AAS regions in the downlink subfraine and the up-link subframe shown in FIG. 2 (b). Multiple downlink bursts and multiple uplink bursts are provided in the AAS regions.

(0032) FIG. 2 (b) also contains a main map and a secondary map. The main map corresponds to mapping information for downlink bursts and uplink bursts to which the AAS does not apply, and the secondary map corresponds to mapping information for downlink bursts and uplink bursts to which the AAS does apply. The uplink subframe also contains channel information.

The channel information is information related to the wireless transmission channel properties measured by the terminal devices 12, and this information is used when executing AAS proc-essing at the base station device 10. In the following explanation, it is assumed that the AAS is applied in order to improve the quality of unicast communication, but the system will be de-scribed based on the frame configuration shown in FIG. 2 (a) for the sake of simplification.

(0033) FIG. 3 is a sequence diagram showing the network entry procedure of the communication system 100. First, processing is performed to obtain the uplink and downlink parameters. The base station device 10 sends notification of the DL[-]MAP and the DCD (Downlink Channel Descriptor) (Sb). The DCD is an MAC message which defines the physical layer properties for downlinking, and it stores the profile information of the physical layers supported by the base station device 10. Such a DCD is periodically sent by broadcast transmission from the base station device 10. The base station device 10 also sends notification of the UL[-]MAP and an UCD (Uplink Channel Descriptor) (S12). The UCD is defined in the same manner as the DCD.

(0034) Next, the initial ranging process is performed. A terminal device 12 transmits an RNG- REQ (Ranging Request) to the base station device 10 (S14). Here, the RNG-REQ is transmit-ted to the ranging region shown in FIG. 2 (a)-(b). The base station device 10 transmits an RNG-RSP (Ranging Response) to the terminal device 12 (S16). In such an initial ranging process, the transmission timing and the transmission power of the terminal device 12 are ad- justed. The process for adjusting the transmission timing and the transmission power is per-formed using well-known technology, so its explanation will be omitted here. Next, a basic capability confirmation process is performed. The terminal device 12 transmits an SBC-REQ (SS Basic Capability Request) to the base station device 10 (S18). The base station device 10 transmits an SBC-RSP (SS Basic Capability Response) to the terminal device 12 (S20).

(0035) Next, terminal authentication and key exchange processes are performed. The terminal device 12 transmits a PKM-REQ (Privacy Key Management Request) to the base station de-vice 10 (S22). The base station device 10 transmits a PKM-RSP (Privacy Key Management Response) to the terminal device 12 (S24). Next, a registration process is performed. The ter-minal device 12 transmits an REG-REQ (Registration Request) to the base station device 10 (S26). The base station device 10 transmits an REG-RSP (Registration Response) to the termi-nal device 12 (S28). Next, an IP setting process is performed. The base station device 10 and the terminal device 12 exchange information related to the IP (Internet Protocol) settings (S30).

After the time information is set and additional function parameters are obtained, data commu-nication is conducted between the base station device 10 and the terminal device 12 (S32).

(0036) FIG. 4 shows the configuration of the base station device 10. The base station device 10 comprises a first antenna 20a, a second antenna 20b, and an Nth antenna 20n, which are collec-tively called antenna 20, a first RF part 22a, a second RF part 22b, and an Nth RF part 22n, which are collectively called RF part 22, a baseband processing part 24, and a controller part 26.

(0037) The RF part 22 receives a signal in the wireless frequency band via the antenna 20 from a terminal device 12 not shown in the figure as a reception operation. Here, the signal in the wireless frequency band is an OFDM signal-in other words, a multicarrier signal. The RF part 22 generates a baseband signal by performing frequency conversion and quadrature detec- tion on the signal in the wireless frequency baud and outputs the baseband signal to the base-band processing part 24. A baseband signal is typically formed from an in-phase component and a quadrature component, so it should be represented as two signal lines, but here the base-band signal is represented as a single signal line in order to make the drawing clear. The RF part 22 also includes an LNA (Low Noise Amplifier) and an AD (Analog-Digital) converter, which are not shown in the figure.

(0038) The RF part 22 receives a baseband signal from the baseband processing part 24 as a transmission operation. Here again, the baseband signal is an OFDM signal-in other words, a multicarrier signal. The RF part 22 generates a signal in the wireless frequency band by per-forming quadrature modulation and frequency conversion on the baseband signal and outputs the signal in the wireless frequency band to the antenna 20. The RF part 22 also includes a PA (Power Amplifier) and a DA (Digital-Analog) converter, which are not shown in the figure.

(0039) The baseband processing part 24 inputs baseband OFDM signals from multiple RF parts 22 as a reception operation. Each baseband OFDM signal is a signal in the time domain, so the baseband processing part 24 converts the signal in the time domain into the frequency domain by using a FFT (Fast Fourier Transform). The baseband processing part 24 also performs adap-tive array signal processing on the signal in the frequency domain in units of the terminal devices 12 not shown in the figure-in other words, in uplink burst units. If the uplink bursts consist of multiple subcarriers, the baseband processing part 24 may perform adaptive array signal processing in subcarrier units. Adaptive array signal processing is performed using well-known technology, so its explanation will be omitted here, but the baseband processing part 24 derives a weight vector and performs adaptive display signal processing based on the weight vector. The baseband processing part 24 then demodulates the OFDM signals that were sub-jected to adaptive array signal processing. Here, demodulation is performed in subcarrier units.

The baseband processing part 24 outputs the demodulated signals to a network or the like, which is not shown in the figure.

(0040) In addition, the baseband processing part 24 generates an OFDM signal in the frequency domain by receiving data from a network not shown in the figure and modulating the data as a transmission operation. The baseband processing part 24 performs distributed processing on the OFDM signal in the frequency domain using a weight vector-in other words, the directiv-ity of the antenna is controlled. The baseband processing part 24 also converts the signal in the frequency domain into the time domain by performing an IFFT (Inverse Fast Fourier Trans-form) on the OFDM signal in the frequency domain. The baseband processing part 24 then outputs the OFDM signal in the time domain to the RF part 22. The above explanation was for the processing of bursts to which the AAS should be applied, and the processing of bursts to which the AAS is not applied will be described below.

(0041) The controller part 26 controls the processes of the RF part 22 and the baseband processing part 24. The controller part 26 defines the frames used in the communication system 100. FIG. (a)-(b) shows the frame format of the base station device 10. FIG. 5 (a) is displayed in the same way as FIG. 2 (a)-(b), where a preamble, an FCH, a DL[-]MAP, and a UL[-]MAP are provided at the beginning of the downlink subframe. Multiple downlink bursts are provided after these components, but they are not shown in FIG. 5 (a).

(0042) The controller part 26 generates FCH, DL[-]MAP, UL[-]MAP, and other notification signals. As described above, these pieces of information are collectively described as a control signal. The controller part 26 generates multiple D signals represented by symbols "Dl" to "DM." Here, each of the multiple D signals is formed from the same content, and the controller part 26 includes at least part of the information of the control signals-for example, informa- tion related to the UL[-]MAP--in each of the multiple D signals. The controller part 26 pro-vides the control signal to the burst at the beginning of the downlink subframe and provides the multiple D signals to bursts which differ from one another in the downlink subframe. Specifi-cally, the multiple D signals are provided to prescribed subcarriers or bursts in the downlink subframe shown in FIG. 5 (a) as the time is shifted. In order to enable AAS processing, a pre-amble is provided at the beginning of each D signal.

(0043) The controller part 26 also defines bursts for receiving multiple R signals represented by symbols "Ri" to "RM" in the uplink subframe. Here, each of the multiple R signals is trans-mitted from a terminal device 12 not shown in the figure and can be considered the same signal as the RNG-REQ used to request ranging. Therefore, the R signals are random access signals.

A ranging region, which is not shown in FIG. 5 (a), may be separately established in the uplink subframe. Here, the burst allocated to each D signal and the burst allocated to each R signal have a one-to-one correspondence. Specifically, the burst to which signal Dl is allocated is associated with the burst to which signal Ri is allocated. Here, the terminal devices 12 which receive the D signals are provided with a rule indicating to transmit the corresponding R sig-nals. For example, the terminal device 12 which receives signal Dl transmits signal Ri. In other words, the controller part 26 provides bursts to which each of D signal is allocated in the downlink subframe so that they are symmetrical with the arrangement of the bursts to which each R signal is allocated in the uplink subframe.

(0044) Taking the above into consideration, the D signals can be considered signals for designating the bursts which transmit R signals to the terminal devices 12. Moreover, the R signals can be considered to be provided to the bursts designated for each of the multiple D signals. After the multiple D signals are provided in this way, the controller part 26 instructs the baseband processing part 24 to generate antenna directivities which differ for each D signal.

FIG. 6 (a)-(c) shows the antenna directivities generated by the controller part 26, which corre-spond to antenna directivity properties in a horizontal plane. In FIG. 6 (a), the region with the greatest anteniia gain faces the direction of"P1," and in FIG. 6 (b) and (c), the regions with the greatest antenna gain face the directions of"P2" and "P3." The discussion now returns to FIG. (a). The technique for generating different types of antenna directivities so that the directions of the regions with the greatest antenna gain differ is called "dithering." The controller part 26 realizes different antenna directivity for each D signal by applying dithering to the multiple D signals. Specifically, the baseband processing part 24 multiplies each D signal by a weight vec-tor to realize dithering.

(0045) The controller part 26 makes the antenna directivity control the same for combinations of corresponding bursts to which the D signals are allocated and bursts to which the R signals are allocated. For example, the controller part 26 makes the antenna directivity for transmitting signal Dl the same as the antenna directivity for receiving signal Ri. In this embodiment, the base station device 10 may receive an RGN-REQ in the ranging region, or it may receive an RGN-REQ in the R signal. In the latter case, the subsequent process should be the same as that shown in FIG. 3, so its explanation is omitted here.

(0046) The frame shown in FIG. 5 (b) is formed in the same way as in FIG. 5 (a). In FIG. 5 (b), multiple D signals and multiple R signals are provided with different frequencies. All other features are the same as in FIG. 5 (a), so their explanations are omitted here. The discussion now returns to FIG. 4. When the network entry is complete, the controller part 26 allocates prescribed bursts to terminal devices 12. As described above, the controller part 26 includes information related to the allocated bursts in the DL-MAP and the UL-MAP. On the other hand, for a terminal device 12 which has received an RNG-REQ in an R signal rather than in the ranging region, the controller part 26 may also include the future DL[-]MAP and UL[-] MAP in the burst that is allocated to this terminal device 12.

(0047) This configuration can be realized on the hardware side with any computer CPU, memory, and other LSIs and on the software with a program with communication functionality that is loaded into memory, but functional blocks realized by the coordination of these components are illustrated here. Therefore, it is to be understood by a person skilled in the art that these functional blocks can be realized in various forms using hardware only, software only, or com-binations thereof (0048) FIG. 7 shows the configuration of a terminal device 12. The terminal device 12 comprises an antenna 30, an RF part 32, a baseband processing part 34, and a controller part 36. The an- tenna 30, RF part 32, baseband processing part 34, a controller part 36 perform operations cor-responding to those of the antenna 20, RF part 22, baseband processing part 24, and controller part 26 shown in FIG. 4. Here, the explanation will focus on the parts that are different. In the network entry procedure, when the controller part 36 receives the control signal provided at the beginning of the downlink subframe via the RF part 32 and the baseband processing part 34, it executes the sequence shown in FIG. 3. On the other hand, if the controller part 36 receives a D signal without receiving the control signal provided at the beginning of the downlink sub-frame via the RF part 32 and the baseband processing part 34, it transmits an RING-REQ in a R signal corresponding to a D signal. The processing is the same as in FIG. 3 thereafter.

(0049) Here, if the controller part 36 receives multiple D signals, the RF part 32 measures the reception power for each of the multiple D signals. The controller part 36 selects the maximum reception power from the multiple reception power levels. The controller part 36 also specifies the D signal corresponding to the selected reception power and transmits an R signal corre-sponding to this D signal. If the controller part 36 receives multiple D signals, it may transmit an R signal corresponding to each of the multiple D signals. In other words, the controller part 36 transmits multiple R signals. At this time, the controller part 26 of the base station device 10, which is not shown in the figure, selects one signal from the multiple R signals.

(0050) Once the network entry is complete, the controller part 36 obtains a DL[-]MAP and UL[- ]MAP via the RF part 32 and the baseband processing part 34 so that it can know the burst that has been allocated to itself The terminal device 12 receives and transmits OFDM signals in the allocated burst. If an RNG-REQ is transmitted in an R signal rather than in the ranging region, the future DL[-]MAP and UL[-]MAP may also be included in the allocated burst.

(0051) The operation of the communication system 100 having the above configuration will now be described. FIG. 8 is a flowchart showing the network entry procedure of the base station device 10. FIG. 8 corresponds to Step 10 to Step 14 in FIG. 3. The controller part 26 generates a control signal (S50) and then generates multiple D signals based on the control signal (S52).

The controller part 26 provides the control signal to the beginning of the downlink subframe and provides multiple D signals corresponding to the directivity patterns (S54). The controller part 26 also provides R signals corresponding to each of the multiple D signals. If the RF part 22 and the baseband processing part 24 receive a random access signal in the ranging region or in an R signal (Y in S56), the controller part 26 continues the network entry process (S58). On the other hand, if the RF part 22 and the baseband processing part 24 do not receive a random access signal in the ranging region or in an R signal (N in S56), the process is ended. The proc-ess from step 50 is then executed repeatedly.

(0052) FIG. 9 is a flowchart showing the network entry procedure of the terminal device 12. If the RF part 32 and the baseband processing part 34 receive the control signal at the beginning of the downlink subframe (Y in S70), the controller part 36 transmits a random access signal us-ing the ranging region via the baseband processing part 34 and the RF part 32 (S72). On the other hand, if the RF part 32 and the baseband processing part 34 receive a D signal (Y in S74) without receiving the control signal at the beginning of the downlink subframe (N in S70), the controller part 36 transmits an R signal corresponding to the received D signal via the base-band processing part 34 and the RF part 32 (S76). The controller part 36 then continues the network entry process (S78). On the other hand, if no D signal is received (N in S74), the process is ended.

(0053) A variation of this embodiment will now be described. In the embodiment, a control signal is provided at the beginning of the downlink subframe, and multiple D signals are provided to the downlink subframe. Moreover, the D signal reception probability at the terminal devices 12 is improved by applying dithering to the multiple D signals. However, part of the content of the control signal is also included in the D signals, so this is equivalent to having part of the content of the control signal sent repeatedly. As a result, the band for transmitting data is re-duced. The purpose of this variation is to suppress decreases in the band for transmitting data while maintaining improvements in the D signal reception probability at the terminal devices 12.

(0054) The communication system 100 in this variation is the same type as in FIG. 1; the base station device 10 is the same type as in FIG. 4; and the terminal device 12 is the same type as in FIG. 7. Therefore, these will be described with focus on the differences between the em-bodiment and the variation. The controller part 26 of the base station device 10 defines a frame such as that shown in FIG. S (a)-(b). The controller part 26 measures the number of times that R signals are received within a prescribed period via the RF part 22 and the baseband process-ing part 24. The controller part 26 also stores a threshold value to be used as a comparison for the number of times signals are received.

(0055) FIG. 10 shows the data structure of the table stored by the controller part 26 in the variation of the present invention. As shown in the figure, the table includes a threshold col- umn 200 and a transmission frequency column 202. The threshold column 200 contains multi-ple threshold values such as "Al" and "A2." Here, the values toward the top of the table-in other words, the values closer to "Al"-indicate larger thresholds. The transmission frequency column 202 contains multiple transmission frequency values such as "Bl" and "B2" corre- sponding to each threshold value. Here, the transmission frequency is equivalent to the fre- quency at which D signals and R signals are provided, and it can also be considered the per-centage of frames to which D signals and R signals are provided. Values toward the top of the table-in other words, values closer to "Bl"-indicate higher frequencies.

(0056) The controller part 26 compares the measured number of times signals are received and the multiple threshold values contained in the threshold column 200. It selects the thresholds satis-fying the relationship "number of times signals are received > threshold value" and specifies the largest of the selected threshold values. The controller part 26 extracts the value of the transmission frequency corresponding to the specified threshold value from the transmission frequency column 202. The controller part 26 then provides D signals and R signals to a frame based on the extracted transmission frequency value. For example, if the extracted transmis-sion frequency value is "1/2," the controller part 26 provides D signals and R signals to one of two frames. In other words, the controller part 26 adjusts the D signal transmission frequency in the downlink subframe based on the status of the reception of R signals.

(0057) FIG. 11 is a flowchart showing the procedure for changing the transmission frequency with the base station device 10 in the variation of the present invention. When the controller part 26 receives an R signal via the RF part 22 and the baseband processing part 24, it measures the R signal reception frequency (S90). The controller part 26 compares the measurement result with the threshold value (S92). If the result of the comparison indicates that the transmission fre-quency should be changed from the present value (Y in S94), the controller part 26 changes the D signal transmission frequency (S96). On the other hand, if the result of the comparison indi-cates that the transmission frequency should not be changed from the present value (N in S94), the controller part 26 ends the process.

(0058) Another variation of this embodiment will be described hereafter. As in the embodiment, the base station device 10 of this variation also applies dithering to multiple D signals. How-ever, the base station device 10 of this variation estimates the directions in which other base station devices 10 are present by measuring the propagation environment in advance. The base station 10 performs dithering so that the antenna directivity is not in the estimated directions (called the "presence directions" hereinafter). Further, the base station device 10 provides separate D signals for other frequencies and adjusts the antenna directivity for the other D sig-nals so that the antenna faces the presence directions.

(0059) The communication system 100 in this variation is the same type as in FIG. 1; the base station device 10 is the same type as in FIG. 4; and the terminal device 12 is the same type as in FIG. 7. Therefore, these will be described with focus on the differences between the embodiment and the variation. The controller part 26 measures the propagation environment in the vicinity of unused bursts. For example, the controller part 26 calculates a weight vector based on a signal received in an unused burst for the baseband processing part 24. For example, the baseband processing part 24 derives a weight vector by using the preamble contained in the received signal. The controller part 26 then calculates the correlation values between the weight vector derived by the baseband processing part 24 and each of the weight vectors for multiple types of dithering which are stored in advance.

(0060) The controller part 26 excludes weight vectors for dithering with correlation values exceeding the threshold value, and it uses the remaining weight vectors for the transmission of D signals and the reception of R signals. These are used exactly as described above, so their explanations are omitted here. The controller part 26 also measures the propagation environ-ment of other frequencies in the vicinity of the baseband processing part 24. If possible, based on comparisons of the correlation values of the excluded weight vectors for dithering and the measured weight vectors, the controller part 26 uses the excluded weight vectors for dithering for the transmission of D signals and the reception of R signals. In this way, the controller part 26 determines the arrangement of bursts to which each D signal is allocated based on the mea-surement results.

(0061) FIG. 12 shows the frame format of this variation of the present invention. FIG. 12 is displayed in the same way as FIG. 5 (a)-(b). However, D signals are provided not only for the frequency at which signal Dl is provided, but also for the frequency at which signal Dl' is provided. For example, the controller part 26 recognizes the presence of another base station device 10 in a presence direction at the frequency at which signal Dl is provided. At this time, the controller part 26 controls the antenna directivity for signals Dl to DM so that the antenna does not face the vicinity of the presence directions. On the other hand, the controller part 26 does not recognize the presence of another base station device 10 in a presence direction at the frequency at which signal Dl' is provided. At this time, the controller part 26 transmits signals Dl' through DM' while using the antenna directivities not used for signals Dl through DM.

The same antenna directivities are also used for signals Ri through RM and signals Ri' through RM'.

(0062) Yet another variation of this embodiment will be described hereafter. Until this point, the arrangements of D signals and R signals in network entry processing were described. This var-iation is related to sending notification of control signals-in particular, the DL[-]MAP and the UL[-]MAP--to terminal devices 12 after network entry processing is complete-in other words, for terminal devices 12 communicating with the base station device 10. As described above, the information related to bursts allocated by the base station device 10 is included in the DL[-]MAP and the UL[-]MAP, so the terminal devices 12 must receive the DL[-]MAP and the UL[-]MAP even during communication.

(0063) Since data signals are transmitted by unicast communication, the AAS can be applied to the data signals, but the DL[-]MAP and the UL[-]MAP are transmitted by broadcast communi-cation, so the AAS cannot be applied to the DL[-]MAP or the like. As a result, the distance over which communication is possible between a terminal device 12 and the base station de-vice 10 is limited to the area in which broadcast communication is possible. Therefore, in this variation, the DL[-]MAP and the UL-MAP are stored in the D signals. For the purpose of clari-fication, the following description will focus only on the DL[-]MAP.

(0064) The communication system 100 of this variation is the same type as in FIG. 1; the base station device 10 is the same type as in FIG. 4; and the terminal device 12 is the same type as in FIG. 7. Therefore, these will be described with focus on the differences between the em-bodiment and the variation. The controller part 26 generates a DL[-]MAP, but when the frame transmitted from this point is defined as the i frame, it generates a DL[-]MAP for the i+lth frame to be transmitted one frame after frame i. In other words, the controller part 26 generates a DL[-]MAP in advance for a frame to be provided at a later stage than the frame to be trans-mitted. Therefore, the DL[-]MAP for the ith frame is already generated.

(0065) The controller part 26 includes the DL[-]MAP for the ith frame generated previously in the control signal and includes the DL[-]MAP for the i+lth frame in each of multiple D signals. In other words, in the controller part 26, the DL[-]MAP for the ith frame is provided at the beginning of the downlink subframe, and the DL[-]MAP for the i+lth frame is provided after the beginning of the downlink subframe. As described above, the antenna directivity is con-trolled differently for each of the multiple D signals.

(0066) Here, the reason for handling the DL[-]MAP for the D signals in this way will be explained.

The DL[-]MAP included in the control signal is provided before the downlink bursts to be mapped. Therefore, even after a terminal device 12 receives this DL[-]MAP and understands its content, it can still receive downlink bursts contained in the same downlink subframe. On the other hand, the multiple D signals are sometimes provided after the downlink bursts to be mapped. In this case, the DL[-]MAP for the downlink bursts to be transmitted is contained in the D signals, as in the case of the control signal. By the time the terminal device 12 receives the DL[-]MAP and understands its content, the downlink bursts in question may have already been deleted. As a result, the terminal device 12 cannot receive downlink bursts contained in the same downlink subframe. In order to resolve this problem, the DL[-]MAPs for the D sig-nals are determined as described above in yet another variation.

(0067) FIG. 13 shows the frame format of yet another variation of the present invention. FIG. 13 is displayed in the same way as FIG. 5 (a)-(b). Multiple frames such as the ith frame and the i+lth frame are shown in FIG. 13. The DL[-]MAP for the ith frame (notated as "DL[-]MAP(i)" in FIG. 13) is provided at the beginning of the downlink subframe of the ith frame. After this DL[-]MAP, a D signal containing the DL[-]MAP for the i+lth frame (notated as "D(i+1)" in FIG. 13) is provided. Further, the DL[-]MAP for the i+lth frame (notated as "DL[-]MAP(i+1)" in FIG. 13) is provided at the beginning of the downlink subframe of the i+lth frame. After this DL[-]MAP, a D signal containing the DL[-]MAP for the i+2th frame (notated as "D(i+2)" in FIG. 13) is provided.

(0068) FIG. 14 is a flowchart showing the DL-MAP transmission procedure of the base station device 10 in this variation of the present invention. The controller part 26 obtains the DL[- ]MAP for the ith frame and generates a DL[-]MAP for the i+ith frame (SilO). The controller part 26 provides the DL[-]MAP for the ith frame at the beginning of the downlink subframe and stores the DL[-]MAP for the i+ith frame in the D signals (Si 12).

(0069) FIG. 15 a flowchart showing the DL-MAP transmission procedure of a terminal device i2 in this variation of the present invention. If a D signal is used (Y in 5130)-in other words, if the DL[-]MAP is obtained with a D signal-the controller part 36 receives the D signal via the RF part 32 and the baseband processing part 34 (S136). The controller part 36 specifies the downlink bursts to be received in the next downlink subframe (S138). On the other hand, if a D signal is not used (N in S130), the controller part 36 receives the DL[-]MAP at the beginning of the downlink subframe via the RF part 32 and the baseband processing part 34 (S132). The controller part 36 then specifies the downlink bursts to be received (S 134).

(0070) In the embodiment of the present invention, multiple combinations of corresponding D signals and R signals are generated, and the antenna directivity control is made to be the same for each combination, so the directivity of the antenna can be controlled in the same way for both uplinking and downlinking, even in broadcast communication. Moreover, since multiple combinations of corresponding D signals and R signals are generated and the antenna directiv-ity control is made to be the same for each combination, the R signal reception properties can be made to be the same as those of D signals. Since dithering is performed for the combina- tions of corresponding D signals and R signals, the reception properties of D signals and R sig-nals can be improved. Further, the improvement of the reception properties of D signals and R signals enables the improvement of the quality of broadcast communication. Since the quality broadcast communication is improved, the effects of imbalances in the communication quality between unicast and broadcast communication can be reduced.

(0071) The area covered by the base station device can be expanded due to the improvement of the reception properties of random access signals. Moreover, since at least part of the informa-tion of the control signal is included in each of the multiple D signals, the broadcast quality can be improved due to the presence of the control signal and the multiple D signals. The arrangements of the bursts for D signals and R signals are made to be the same, so the trans-mission of information regarding the allocation of random access signals can be omitted. Since the arrangements of the bursts for D signals and R signals are made to be the same, the proc- essing performed at the terminal devices can be simplified. Moreover, each D signal is allo-cated based on the propagation environment, so each D signal can be allocated in a manner suited to the propagation environment. Since the antenna directivity of each D signal can be controlled based on the propagation environment, each D signal can be transmitted in a manner suited to the propagation environment.

(0072) The transmission frequency of D signals can also be adjusted based on the status of the reception of R signals, so decreases in transmission efficiency can be suppressed. Since the transmission frequency of D signals can also be adjusted based on the status of the reception of R signals, decreases in transmission efficiency can be suppressed while maintaining the quality of broadcast communication. Information related to frames following the frame where the con-trol signal is provided is included in each of the multiple D signals, so the degree of freedom [in the arrangement] of bursts to which the multiple D signals are allocated can be improved.

Since information related to frames following the frame where the control signal is provided is included in each of the multiple D signals, subsequent frames can be received even if D signals are received. In addition, the broadcast quality can be improved since the antenna directivity control is made to be different for each of the multiple D signals.

(0073) The present invention was described above based on an embodiment. This embodiment is an example of the present invention, and it is to be understood by a person skilled in the art that various variations are possible in the combinations of each component and each processing process and that such variations are within the scope of the present invention.

(0074) In the embodiment of the present invention, the communication system 100 employs OFDMA. However, the present invention is not limited to this configuration, and the commu-nication system 100 may instead employ only TDMA without using OFDMA. In this case, the physical layers may be either OFDM or SC. This variation allows present invention to be ap-plied to various communication systems. In other words, a frame formed from multiple bursts should be defined, and the control signal to be broadcast should be provided at the beginning of the frame.

(0075) In the embodiment of the present invention, the communication system 100 first coordinates the D signals and R signals with a one-to-one correspondence and then establishes rules so that the arrangement of D signals in the downlink subframe is symmetrical to the ar-rangement of R signals in the uplink subframe. However, the present invention is not limited to this configuration, and the communication system 100 may also establish rules so that the ar-rangement of D signals in the downlink subframe is not symmetrical to the arrangement of R signals in the uplink subframe. In this case, the base station device 10 includes in the D signals information for specifying the bursts to which the corresponding R signals are allocated. This variation makes it possible to improve the degree of freedom in the arrangement of D signals in the downlink subframe or the arrangement of R signals in the uplink subframe.

FIELD OF INDUSTRIAL APPLICATION

(0076) With the present invention, it is possible to reduce the effects of imbalances in the communication quality between unicast and broadcast communication.

Claims

SCOPE OF THE PATENT CLAIMSA base station device which defines a frame formed from a downlink subframe containing multiple bursts and an uplink subframe containing multiple burst, equipped with: a generation part which generates at least two control signals for designating bursts which transmit random access signals to a terminal device in a single downlink subframe; a transmission part which allocates each of the at least two control signals generated by said generation part to bursts which differ from one another in the downlink subframe and transmits them; a reception part which receives the random access signals from the terminal device in bursts designated for each of the at least two control signals transmitted from said transmission part, which are bursts in an uplink subframe with a one-to-one correspondence to the bursts to which each control signal is allocated; and a controller part which controls the operation of the reception part and the transmission part; wherein said controller part makes the directivity control of the antenna the same for combinations of corresponding bursts to which control signals are allocated and bursts to which random access signals are allocated.
2 The base station device according to Claim 1, wherein said transmission part is provided with bursts to which each control signal is allocated in the downlink subframe so that they are symmetrical with the arrangement of the bursts to which each random access signal is allo-cated in the uplink subframe.
3 The base station device according to Claim 1 or 2 which is further equipped with a measurement part for measuring the propagation environment; wherein said transmission part determines the arrangement of the bursts to which each control signal is allocated based on the results of measurement by the measurement part.
4 The base station device according to one of Claims 1 through 3, wherein said transmission part also provides a control signal to the burst at the beginning of the downlink subframe, and the transmission frequency of control signals other than the control signal provided to the burst at the beginning of the downlink subframe is adjusted based on the status of the reception of random access signals by said reception part.
A base station device which defines a frame containing multiple bursts, equipped with: a generation part which generates a first control signal and multiple second control signals; and a transmission part which provides the first control signal generated by said generation part to the burst at the beginning of the frame and provides the multiple second control signals to bursts which differ from one another and transmits them; wherein said generation part includes at least part of the information of the first control signal in each of the multiple second control signals.
6 A base station device which repeatedly defines frames containing multiple bursts, equipped with: a generation part which generates a first control signal and multiple second control signals; and a transmission part which provides the first control signal generated by said generation part to the burst at the beginning of the frame and provides the multiple second control signals to bursts which differ from one another and transmits them; wherein said generation part includes information related to the frame where the first control signal is provided in the first control signal and includes information related to frames following the frame where the first control signal is provided in each of the multiple second control signals.
7 The base station device according to Claim 5 or 6 which is further equipped with a controller part for controlling the operation of the transmission part; wherein said controller part makes the antenna directivity control different for each of the multiple second control signals.
8 A designation method for random access signals comprising: a step in which a frame formed from a downlink subframe containing multiple bursts and an uplink subframe containing multiple bursts is defined and at least two control signals for designating bursts which transmit random access signals to a terminal device are generated in a single downlink subframe; a step in which the at least two control signals that are generated are allocated to bursts which differ from one another in the downlink subframe and are transmitted; and a step in which the random access signals from the terminal device are received in bursts designated for each of the at least two control signals that are transmitted, which are bursts in an uplink frame with a one-to-one correspondence to the bursts to which each control signal is allocated; wherein, in said transmission step and said reception step, the directivity control of the antenna is made to be the same for combinations of corresponding bursts to which control sig-nals are allocated and bursts to which random access signals are allocated.
9 A communication method comprising: a step in which a first control signal and multiple second control signals are generated; and a step in which, after a frame containing multiple bursts is defined, the generated first control signal is provided to the burst at the beginning of the frame, and the multiple second control signals are provided to bursts which differ from one another and are transmitted; wherein, iii said generation step, at least part of the information of the first control signal is included in each of the multiple second control signals.
A communication method comprising: a step in which a first control signal and multiple second control signals are generated; and a step in which, after frames containing multiple bursts are repeatedly defined, the generated first control signal is provided to the burst at the beginning of the frame, and the multiple second control signals are provided to bursts which differ from one another and are transmitted; wherein, in said generation step, information related to the frame where the first control signal is provided is included in the first control signal, and information related to frames fol-lowing the frame where the first control signal is provided is included in each of the multiple second control signals.
11 A program executed on a computer comprising: a step in which a frame formed from a downlink subframe containing multiple bursts and an uplink subframe containing multiple bursts is defined and at least two control signals for designating bursts which transmit random access signals to a terminal device are generated in a single downlink subframe; a step in which the at least two control signals that are generated are allocated to bursts which differ from one another in the downlink subframe and are transmitted; and a step in which the random access signals from the terminal device are received in bursts designated for each of the at least two control signals that are transmitted, which are bursts in an uplink frame with a one-to-one correspondence to the bursts to which each control signal is allocated; wherein, in said transmission step and said reception step, the directivity control of the antenna is made to be the same for combinatioiis of corresponding bursts to which control sig-nals are allocated and bursts to which random access signals are allocated.
12 A program executed on a computer comprising: a step in which a first control signal and multiple second control signals are generated; and a step in which, after a frame containing multiple bursts is defined, the generated first control signal is provided to the burst at the beginning of the frame, and the multiple second control signals are provided to bursts which differ from one another and are transmitted; wherein, in said generation step, at least part of the information of the first control signal is included in each of the multiple second control signals.
13 A program executed on a computer comprising: a step in which a first control signal and multiple second control signals are generated; and a step in which, after frames containing multiple bursts are repeatedly defined, the generated first control signal is provided to the burst at the beginning of the frame, and the multiple second control signals are provided to bursts which differ from one another and are transmitted; wherein, in said generation step, information related to the frame where the first control signal is provided is included in the first control signal, and information related to frames fol-lowing the frame where the first control signal is provided is included in each of the multiple second control signals.
14. A base station device substantially as described hereinbefore with reference to the accompanying drawings.
15. A communication method substantially as described hereinbefore with reference to the accompanying drawings.
16. A program executed on a computer substantially as described hereinbefore with reference to the accompanying drawings.