JP5278586B2 - Wireless communication system, mobile station and base station - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve processing efficiency of random access from a mobile station to a base station. <P>SOLUTION: A radio communication system comprises a mobile station and a base station. The mobile station does not simultaneously perform a first random access procedure for achieving uplink synchronization by transmitting an individual random access signal designated by the base station to the base station, when a first event occurs; and a second random access procedure for achieving uplink synchronization by transmitting a non-individual random access signal selected by the mobile station to the base station, when a second event occurs. <P>COPYRIGHT: (C)2013,JPO&amp;INPIT

Description

  The present invention relates to a wireless communication system, a mobile station, and a base station.

  Currently, mobile communication systems that perform wireless communication between a radio base station and a mobile station are widely used. In a mobile communication system, a radio base station uses radio resources (frequency resources, time resources, etc.) for both communication from a radio base station to a mobile station (downlink communication) and communication from a mobile station to a radio base station (uplink communication). Can be managed. In this case, the mobile station receives uplink radio resource assignment from the radio base station, and performs uplink data transmission using the assigned uplink radio resource.

  In such a mobile communication system, some uplink radio resources may be allocated to a random access channel in advance. The mobile station can transmit a signal (random access signal) on the random access channel even in a state where no resource allocation is received. At this time, in preparation for a collision of random access signals from a plurality of mobile stations, the radio base station may individually designate a signal (preamble signal) to be transmitted by the preamble part of the random access channel to each mobile station. Examples of the use of the random access channel include the following (see Non-Patent Document 1, for example).

  Considering an example in which the radio base station transmits downlink data to the mobile station, the radio base station first designates a preamble signal that is permitted to be used. The mobile station transmits a designated preamble signal through a random access channel. The radio base station measures a timing shift based on a random access signal (preamble signal designated by the radio base station) received from the mobile station, and instructs the mobile station to adjust the timing. The mobile station corrects the transmission timing. Thereafter, the radio base station transmits downlink data to the mobile station. The mobile station transmits ACK (ACKnowledgement) / NACK (Negative ACKnowledgement) indicating the data reception result to the radio base station at the corrected timing. Thus, in downlink data communication, uplink timing can be synchronized using a random access channel.

  Considering an example in which the mobile station performs uplink data transmission to the radio base station, the mobile station first selects a preamble signal from a plurality of candidates based on a random number, and transmits it using a random access channel. When the radio base station receives a random access signal (a preamble signal not designated by the radio base station) from the mobile station, the radio base station allocates uplink radio resources for control data to the mobile station. The mobile station transmits a data transmission request (for example, BSR: Buffer Status Report) using the allocated uplink radio resource. The radio base station allocates an uplink radio resource having a size corresponding to the data transmission request from the mobile station. Thereafter, the mobile station transmits uplink data to the radio base station. In this way, the mobile station can start uplink data transmission using the random access channel.

3rd Generation Partnership Project, "Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)", 3GPP TS36.300, 2008-03 V8. 4.0.

  However, the random access method as described above has a problem that the procedure is executed independently for each cause of random access, and the processing is inefficient. That is, in random access during downlink data communication, it is only necessary to establish uplink timing synchronization, so it is determined that uplink radio resource allocation is unnecessary. For this reason, in the case of downlink data communication, when the mobile station also wants to transmit control data (for example, when starting uplink data communication), a separate random access procedure is required for allocation of uplink radio resources. Become.

  The present invention has been made in view of these points, and an object thereof is to provide a radio communication system, a mobile station, and a base station that can improve the processing efficiency of random access.

  In one aspect, a wireless communication system comprising a base station and a mobile station is provided. When the first event occurs, the mobile station transmits an individual random access signal designated by the base station to the base station to synchronize the uplink, and when the second event occurs. The second random access procedure for synchronizing the uplink by transmitting the non-individual random access signal selected by the mobile station to the base station is not performed simultaneously.

  Moreover, in one aspect, a mobile station provided with a transmission part and a control part is provided. The transmission unit transmits a signal to the base station. When the first event occurs, the control unit causes the first random access procedure specified by the base station to transmit the individual random access signal from the transmission unit to the base station, thereby synchronizing the uplink, and the second event occurs. In this case, the non-individual random access signal selected by the local station is transmitted from the transmission unit to the base station, so that the transmission unit is controlled not to perform the second random access procedure for uplink synchronization at the same time.

  In one aspect, a base station including a receiving unit is provided. The receiving unit moves when a first event occurs and a first random access procedure for synchronizing uplink by transmitting an individual random access signal designated by the base station to the base station when the first event occurs, and when a second event occurs. An individual random access signal or a non-individual random access signal is received from a mobile station that does not simultaneously perform the second random access procedure for synchronizing uplink by transmitting a non-individual random access signal selected by the station to the base station.

  According to the wireless communication system, mobile station, and base station, the processing efficiency of random access is improved.

It is a figure which shows the outline | summary of a radio | wireless communications system. It is a figure which shows the system configuration | structure of a radio | wireless communications system. It is a figure which shows the block configuration of a radio base station. It is a figure which shows the block configuration of a mobile station. It is a figure which shows a radio | wireless frame structure. It is a figure which shows a downlink communication channel. It is a figure which shows an uplink communication channel. It is a figure which shows the kind of preamble signal. It is a figure which shows the structure of the data transmitted after RA response. It is a flowchart which shows RA control of a wireless base station. It is a flowchart which shows RA control of a mobile station. It is a sequence diagram which shows downlink data communication. It is a sequence diagram which shows uplink data communication. FIG. 3 is a first sequence diagram showing uplink and downlink data communication. It is a 2nd sequence diagram which shows uplink and downlink data communication. It is a sequence diagram which shows a handover process.

Hereinafter, the present embodiment will be described in detail with reference to the drawings.
FIG. 1 is a diagram illustrating an outline of a wireless communication system. This radio communication system has a radio base station 1 and a mobile station 2. Between the radio base station 1 and the mobile station 2, radio communication in the downlink direction (radio base station 1 to mobile station 2) and the uplink direction (mobile station 2 to radio base station 1) can be performed.

  The radio base station 1 includes a reception unit 1a and a transmission unit 1b. The receiving unit 1a receives various data including control data from the mobile station 2 via an uplink data channel or an uplink control channel. The receiving unit 1a receives a random access signal via a random access channel. The transmission unit 1b transmits various data including control data to the mobile station 2 via a downlink data channel or a downlink control channel.

  The mobile station 2 has a receiving unit 2a and a transmitting unit 2b. The receiving unit 2a receives various data including control data from the radio base station 1 via a downlink data channel or a downlink control channel. The transmission unit 2b transmits various data including control data to the radio base station 1 via an uplink data channel or an uplink control channel. Further, the transmission unit 2b transmits a random access signal to the radio base station 1 via a random access channel.

  Here, when performing downlink data communication from the radio base station 1 to the mobile station 2, the transmission unit 1 b of the radio base station 1 transmits designation information of a random access signal permitted to be used by the mobile station 2. The designation information includes, for example, a number indicating the type of preamble signal. The transmitter 2b of the mobile station 2 transmits the designated random access signal to the radio base station 1.

  The radio base station 1 measures a shift in uplink communication timing based on a random access signal (for example, a preamble signal) received by the receiving unit 1a. In addition, the radio base station 1 allocates uplink radio resources to the mobile station 2. All the uplink radio resources to be allocated in response to the random access signal may be unified to a predetermined size (resource amount) regardless of the cause of random access. Then, the transmission unit 1b of the radio base station 1 transmits timing adjustment information and uplink radio resource allocation information to the mobile station 2 as a response to the random access signal.

  The mobile station 2 corrects the uplink transmission timing based on the timing adjustment information received by the receiving unit 2a. Then, the transmitter 2b of the mobile station 2 transmits control data using the allocated uplink radio resource. As the control data to be transmitted, for example, a synchronization completion report, a data transmission request (for example, BSR), an RRC (Radio Resource Control) message related to connection control, and the like can be considered.

  The synchronization completion report may be omitted when there is other control data to be transmitted. Also, a plurality of types of control data can be transmitted simultaneously as long as the size is within the allocated uplink radio resource size. On the other hand, when the amount of control data to be transmitted exceeds the allocated size, it is conceivable to transmit some control data and information on the remaining data amount.

  Thereafter, the transmission unit 1 b of the radio base station 1 performs downlink data transmission to the mobile station 2. At this time, the radio base station 1 is synchronized with the mobile station 2 by receiving control data (synchronization completion report or other type of control data transmitted instead of the synchronization completion report) by the receiving unit 1a. You can know that it was taken. In addition, when the data transmission request or the remaining data amount information is received as control data by the receiving unit 1a, the radio base station 1 further allocates uplink radio resources having a size corresponding to the contents to the mobile station 2. .

  According to such a radio communication system, the random access signal designation information is transmitted to the mobile station 2 by the transmitter 1b of the radio base station 1 during downlink data communication from the radio base station 1 to the mobile station 2. . A designated random access signal is transmitted to the radio base station 1 by the transmitter 2 b of the mobile station 2. The transmitter 1b of the radio base station 1 transmits timing adjustment information based on the reception result of the random access signal and uplink radio resource allocation information used for transmission of control data to the mobile station 2.

  Thereby, the processing efficiency of random access is improved. That is, uplink radio resources are allocated to the mobile station 2 even in random access for the purpose of timing synchronization in downlink data communication. For this reason, when the mobile station 2 wants to transmit control data together with downlink data communication, the allocated uplink radio resource can be used, and separate random access is not required. In addition, after the random access response including the timing adjustment information, the mobile station 2 transmits some control data to the radio base station 1 so that the radio base station 1 knows at an early stage that the timing synchronization is successful. Can do.

Hereinafter, specific contents of the present embodiment will be described.
FIG. 2 is a diagram illustrating a system configuration of the wireless communication system. The radio communication system shown in FIG. 2 includes radio base stations 100 and 100a and mobile stations 200 and 200a.

  The radio base stations 100 and 100a are radio communication devices that can communicate with radio terminal devices that exist within the respective radio wave reachable ranges. The radio base stations 100 and 100a can communicate with each other via an upper station (not shown). The mobile stations 200 and 200a are wireless terminal devices that can communicate with the wireless base stations 100 and 100a, and are mobile phones, for example.

  The radio base stations 100 and 100a and the mobile stations 200 and 200a can perform bidirectional communication (uplink communication and downlink communication). At this time, radio resources used in radio communication are managed on the radio base stations 100 and 100a side. That is, the mobile stations 200 and 200a can perform uplink data transmission by receiving uplink radio resource assignment from the radio base stations 100 and 100a.

  FIG. 3 is a diagram illustrating a block configuration of the radio base station. The radio base station 100 includes an antenna 110, a reception unit 120, a data processing unit 130, a transmission buffer 140, a control unit 150, and a transmission unit 160. The radio base station 100a can also be realized by the same configuration as the radio base station 100.

  The antenna 110 is a transmission / reception antenna. The antenna 110 outputs the radio signal received from the mobile stations 200 and 200a to the receiving unit 120. In addition, the antenna 110 wirelessly outputs the transmission signal acquired from the transmission unit 160. Note that a transmitting antenna and a receiving antenna may be provided separately.

  The receiving unit 120 demodulates and decodes the received signal acquired from the antenna 110, and includes user data (for example, voice data, e-mail data, image data) included in the uplink data channel, an uplink data channel, and an uplink control channel. And control data included in. In addition, the receiving unit 120 extracts a random access channel signal (random access signal). Then, the receiving unit 120 outputs the extracted user data to the data processing unit 130. Further, the extracted control data and random access signal are output to the control unit 150.

  The data processing unit 130 processes user data acquired from the receiving unit 120 and user data acquired from other radio base stations via a higher-level station. For example, the data processing unit 130 executes processing according to the type of user data. Then, the data processing unit 130 outputs user data to be transmitted to the mobile station existing within the radio wave reachable range of the radio base station 100 to the transmission buffer 140.

  The transmission buffer 140 is a buffer memory that temporarily holds user data. The transmission buffer 140 holds user data acquired from the data processing unit 130. Further, the transmission buffer 140 outputs user data to the transmission unit 160 in response to an instruction from the control unit 150. At this time, the transmission buffer 140 can classify and hold user data for each destination and type, and can preferentially output user data of a specific destination and type instructed from the control unit 150. is there.

  The control unit 150 controls radio communication processing of the radio base station 100. The control unit 150 includes a timing measurement unit 151, a UL (UpLink) resource allocation unit 152, a transmission control unit 153, and a preamble number designation unit 154.

  The timing measurement unit 151 measures the difference between the reception timing expected by the radio base station 100 and the actual reception timing from the mobile stations 200 and 200a based on the random access signal acquired from the reception unit 120. For timing measurement, a signal (preamble signal) of the preamble part can be used. Then, the timing measurement unit 151 generates a synchronization command for timing correction and outputs it to the transmission unit 160. In addition, the timing measurement unit 151 notifies the UL resource allocation unit 152 that a random access signal has been received.

  When receiving a notification that the random access signal has been received from the timing measurement unit 151, the UL resource allocation unit 152 allocates an uplink radio resource having a predetermined size as an uplink data channel to the transmission source of the random access signal. The size of the uplink radio resource to be allocated upon receiving the random access signal may be, for example, about the BSR data amount.

  Further, when acquiring the control data from the reception unit 120, the UL resource allocation unit 152 allocates an uplink radio resource having a size corresponding to the content of the control data to the transmission source of the control data. After the uplink radio resource is allocated, the UL resource allocation unit 152 generates allocation information (UL grant) and outputs the allocation information (UL grant) to the transmission unit 160. The allocation information includes allocation size information (for example, the number of bits and the number of blocks).

  When the transmission control unit 153 obtains control data from the mobile stations 200 and 200a after a response to random access (random access response) is performed, the transmission control unit 153 sends user data addressed to the mobile stations 200 and 200a to the transmission buffer 140. Instruct to output. As the control data acquired at this time, for example, a synchronization completion report, a BSR or RRC message transmitted instead of the synchronization completion report, and the like can be considered.

  The preamble number designation unit 154 monitors the arrival status of user data at the transmission buffer 140. When user data addressed to the mobile stations 200 and 200a arrives, the preamble number designation unit 154 designates preambles to be used by the mobile stations 200 and 200a from a plurality of candidates prepared in advance. The designated preamble is not used by other mobile stations for a predetermined time thereafter. Then, preamble number designating unit 154 outputs a preamble number indicating the designated preamble to transmitting unit 160.

  The transmission unit 160 encodes / modulates user data acquired from the transmission buffer 140 and various control data (such as synchronization command, allocation information, preamble number) acquired from the control unit 150, and a downlink data channel and a downlink control data channel The transmission signal is generated. Then, transmission section 160 outputs the generated transmission signal to antenna 110.

  FIG. 4 is a diagram illustrating a block configuration of the mobile station. The mobile station 200 includes an antenna 210, a reception unit 220, a data processing unit 230, a transmission buffer 240, a control unit 250, and a transmission unit 260. The mobile station 200a can also be realized by the same configuration as the mobile station 200.

  The antenna 210 is a transmission / reception antenna. Radio signals received from the radio base stations 100 and 100 a are output to the receiving unit 220. Further, the antenna 210 wirelessly outputs the transmission signal acquired from the transmission unit 260. Note that a transmitting antenna and a receiving antenna may be provided separately.

  The receiving unit 220 demodulates and decodes the received signal acquired from the antenna 210, and extracts user data included in the downlink data channel and control data included in the downlink data channel and the downlink control channel. Then, the receiving unit 220 outputs the extracted user data to the data processing unit 230. The extracted control data is output to the control unit 250.

  The data processing unit 230 processes the user data acquired from the receiving unit 220 according to the type. For example, the data processing unit 230 executes text and image display processing, audio reproduction processing, and the like. In addition, the data processing unit 230 generates user data to be transmitted to the radio base station 100 and outputs the user data to the transmission buffer 240.

  The transmission buffer 240 is a buffer memory that temporarily holds user data. The transmission buffer 240 holds user data acquired from the data processing unit 230. In addition, the transmission buffer 240 outputs the amount of user data instructed by the control unit 250 to the transmission unit 260.

  The control unit 250 controls the wireless communication process of the mobile station 200. The control unit 250 includes a timing correction unit 251, a preamble generation unit 252, a transmission control unit 253, and a control data generation unit 254.

  When the timing correction unit 251 acquires a synchronization command as control data from the reception unit 220, the timing correction unit 251 corrects the uplink transmission timing based on the synchronization command. Then, the timing correction unit 251 notifies the control data generation unit 254 that the timing correction has been completed.

  When the preamble generation unit 252 acquires the preamble number as control data from the reception unit 220, the preamble generation unit 252 generates a preamble signal sequence (sequence) indicated by the preamble number and outputs the preamble signal sequence (sequence) to the transmission unit 260. As a case where a specified individual preamble signal is generated, for example, the start of downlink data communication or the handover can be considered.

  Further, when transmission of control data is necessary in a situation where no preamble number is specified, the preamble generation unit 252 selects a preamble number using a random number, and generates a preamble signal corresponding to the selected preamble number. For example, when a non-individual preamble signal not specified is generated, for example, initial connection after power-on, reconnection associated with disconnection, or start of uplink data transmission may be considered.

  Note that the preamble generation unit 252 agrees in advance with the radio base stations 100 and 100a regarding the correspondence between the preamble number and the type of preamble signal. This correspondence may be fixed, or information on the correspondence may be acquired from the radio base stations 100 and 100a at the start of communication. Further, the correspondence relationship may be different for each radio base station.

  The transmission control unit 253 controls transmission of user data and control data based on uplink radio resource allocation information (UL grant) acquired as control data from the reception unit 220. When transmitting user data, the transmission control unit 253 notifies the transmission buffer 240 of the amount of user data that can be transmitted. When transmitting control data, the control data generation unit 254 is notified of the amount of control data that can be transmitted.

  The control data generation unit 254 generates various control data and outputs it to the transmission unit 260 in response to the notification from the transmission control unit 253. For example, the control data generation unit 254 monitors the arrival status of user data to the transmission buffer 240 and generates a BSR indicating the amount of user data. In addition, an RRC message is generated at the time of initial connection, reconnection, and handover to the radio base stations 100 and 100a. In addition, when data is received from the radio base stations 100 and 100a, ACK / NACK is generated.

  In addition, when the control data generation unit 254 receives a timing correction completion notification from the timing correction unit 251, if there is no particular control data to be transmitted, the control data generation unit 254 generates a synchronization completion report. On the other hand, if the allocated size of the uplink radio resource is smaller than the amount of control data to be transmitted, a part of the control data to be transmitted is output to the transmitter 260, and the control data is generated and transmitted indicating the remaining data amount. Output to the unit 260.

  The transmission unit 260 encodes and modulates the user data acquired from the transmission buffer 240 and the control data acquired from the control unit 250, and generates transmission signals of the uplink data channel and the uplink control channel. Further, the transmission unit 260 uses the preamble acquired from the control unit 250 as a transmission signal of the preamble portion of the random access channel. Transmitting section 260 then outputs the obtained transmission signal to antenna 210.

  FIG. 5 is a diagram illustrating a radio frame structure. In the present embodiment, OFDM (Orthogonal Frequency Division Multiplexing) or SC-FDM (Single Carrier-Frequency Division Multiplexing) can be adopted as a multiplex communication method. For example, radio frames as shown in FIG. 5 are transmitted and received between the radio base stations 100 and 100a and the mobile stations 200 and 200a. In this example, the time width of one frame is 10 ms (milliseconds). One frame includes a plurality of subframes. The time width of one subframe is 1 ms.

  In each subframe, management is performed by subdividing frequency resources × time resources. The minimum unit in the frequency axis direction is called a subcarrier. The minimum unit in the time axis direction is called a symbol. The minimum unit specified by one subcarrier and one symbol is called a resource element. Allocation of radio resources is performed in units of resource blocks that straddle a plurality of subcarriers (for example, 12 subcarriers). Of the time width of 1 ms of the subframe, the first half 0.5 ms and the second half 0.5 ms are each called a slot.

  Some of such radio resources include a downlink data channel (PDSCH: Physical Downlink Shared CHannel), a downlink control channel (PDCCH: Physical Downlink Control CHannel), an uplink data channel (PUSCH: Physical Uplink Shared CHannel), and uplink control, respectively. It is used as a channel (PUCCH: Physical Uplink Control CHannel) and a random access channel (RACH: Random Access CHannel).

  FIG. 6 is a diagram illustrating a downlink communication channel. In downlink communication from the radio base stations 100 and 100a to the mobile stations 200 and 200a, for example, a communication channel as shown in FIG. 6 is formed in each subframe. The downlink communication channel includes a downlink control channel and a downlink data channel.

  A radio resource having a predetermined symbol length (for example, 1 to 3 symbols) is allocated to the downlink control channel from the top of the subframe. The plurality of downlink control channels are frequency multiplexed. The mobile stations 200 and 200a are notified from the radio base stations 100 and 100a of downlink control channels that may be used for transmission of control data addressed to the mobile stations 200 and 200a. The mobile stations 200 and 200a monitor the notified downlink control channel and detect downlink control data addressed to the mobile station. In the downlink control channel, various control data (for example, downlink data channel position information including uplink data resource information including data addressed to the mobile stations 200 and 200a, uplink radio resource allocation information, etc.) is transmitted.

  A part of radio resources other than radio resources used for the downlink control channel is allocated to the downlink data channel. The plurality of downlink data channels are frequency multiplexed. The downlink data channel is time-multiplexed with the downlink control channel. The amount of radio resources used in each downlink data channel is variable. The mobile stations 200 and 200a specify a downlink data channel including data addressed to the mobile station based on the control data acquired through the downlink control channel. In the downlink data channel, user data and some control data (for example, random access response) are transmitted.

  FIG. 7 is a diagram illustrating an uplink communication channel. In uplink communication from the mobile stations 200 and 200a to the radio base stations 100 and 100a, for example, a communication channel as shown in FIG. 7 is formed in each subframe. The uplink communication channel includes an uplink control channel, an uplink data channel, and a random access channel.

  Radio resources having a predetermined frequency width are allocated to the uplink control channel from both ends of all frequency bands (system bands) that can be used by the radio base stations 100 and 100a. Each uplink subframe includes two control channels. The first control channel (uplink control channel i) is assigned to the high frequency side of the first half slot and the low frequency side of the second half slot. The second control channel (uplink control channel j) is assigned to the low frequency side of the first half slot and the high frequency side of the second half slot.

  In each uplink control channel, data for a plurality of mobile stations is code-multiplexed and transmitted. The mobile stations 200 and 200a can transmit predetermined types of control data such as ACK / NACK using one of the uplink control channels i and j. However, when the uplink data channel is allocated, the mobile stations 200 and 200a use the uplink data channel without using the uplink control channel. When there are many mobile stations accommodated by the radio base stations 100 and 100a, another uplink control channel can be provided inside the uplink control channels i and j.

  A part of the frequency band other than the frequency band used for the uplink control channel is allocated to the uplink data channel. The plurality of uplink data channels are frequency multiplexed. The mobile stations 200 and 200a identify the uplink data channel assigned to the mobile station based on the assignment information received through the downlink control channel. In the uplink data channel, user data and various control data (for example, BSR, RRC message, ACK / NACK, etc.) are transmitted.

  A part of the frequency band other than the frequency band used for the uplink control channel is allocated to the random access channel. The random access channel is not necessarily included in all subframes. For example, at least one random access channel is provided in one frame. The position of the random access channel is agreed between the radio base stations 100 and 100a and the mobile stations 200 and 200a.

  In the random access channel, a random access signal including a preamble part is transmitted. The radio base stations 100 and 100a can individually identify a plurality of signals received through the same random access channel if the types of preamble signals are different (if the preamble numbers are different). On the other hand, random access signals having the same type of preamble signal cannot be individually identified. In this case, the random access fails.

  FIG. 8 is a diagram illustrating the types of preamble signals. Each of the radio base stations 100 and 100a prepares N types of preamble signal sequences (sequences) from No. 1 to No. N (1 <N) as preambles. Among these, preambles from No. 1 to No. K (1 <K <N) are reserved for individual allocation. The preambles from the (K + 1) th to the Nth preamble can be used by the mobile stations 200 and 200a without individual allocation.

  That is, use permission management of the preambles from No. 1 to No. K is performed by the radio base stations 100 and 100a. Therefore, when these preambles are used, random access collision can be prevented. On the other hand, the preambles from the (K + 1) th to the Nth are not managed for use permission and are used at the judgment of the mobile stations 200 and 200a. Therefore, when these preambles are used, random access may fail due to collision. Note that the preamble reserved for individual allocation does not necessarily have a small number as shown in FIG. 8, and a preamble with an arbitrary number can be selected.

  FIG. 9 is a diagram illustrating a structure of data transmitted after the RA response. When the mobile stations 200 and 200a receive a random access response from the radio base stations 100 and 100a, the mobile stations 200 and 200a transmit control data in a format as shown in FIG. 9, for example. This format has a header part and an information part. The header part includes an identifier (Logical Channel ID) indicating the type of control data. The information part includes the contents of the control data.

  When a plurality of control data are transmitted at a time, a plurality of items are provided in the header part and the information part, respectively. In the example of FIG. 9, header # 1 and information # 1, header # 2 and information # 2, and header #N and information #N correspond to each other. For example, the mobile stations 200 and 200a may transmit an identifier indicating the remaining data amount control data as the header #N, and transmit a numerical value (for example, the number of bits) indicating the remaining data amount as the information #N. it can. The radio base stations 100 and 100a can recognize the type of each received control data by referring to the header part, and execute processing according to the type of control data.

Next, details of processing executed in the wireless communication system as described above will be described.
FIG. 10 is a flowchart showing RA control of the radio base station. Here, consider a case where the radio base station 100 and the mobile station 200 perform radio communication. In the following, the process illustrated in FIG. 10 will be described in order of step number.

  [Step S11] The preamble number specifying unit 154 determines whether there is user data to be transmitted to the mobile station 200. If there is user data to be transmitted, the process proceeds to step S12. If there is no user data to be transmitted, the process proceeds to step S13.

  [Step S12] The preamble number specifying unit 154 selects one of the preambles for individual allocation that has not been allocated to another mobile station such as the mobile station 200a, and allocates it to the mobile station 200. The transmission unit 160 transmits the preamble number to the mobile station 200 through the downlink data channel.

  [Step S13] The receiving unit 120 receives a random access signal including the preamble specified in Step S12 or the preamble selected by the mobile station 200 from the mobile station 200 using a random access channel.

  [Step S14] The timing measurement unit 151 measures the difference between the expected reception timing and the actual reception timing based on the preamble signal of the random access signal received in step S13. Then, the timing measurement unit 151 generates a synchronization command for correcting the transmission timing.

  [Step S15] The UL resource allocation unit 152 allocates an uplink radio resource having a fixed size (for example, a size corresponding to the data amount of BSR) independent of the cause of random access to the mobile station 200 as an uplink data channel. Then, UL resource allocation section 152 generates uplink radio resource allocation information.

  [Step S16] The transmission unit 160 transmits a random access response including the synchronization command generated in step S14 and the allocation information generated in step S15 to the mobile station 200 via the downlink data channel.

  [Step S17] The receiving unit 120 receives control data from the mobile station 200 using the uplink radio resource (uplink data channel) allocated in step S15. As the control data received here, for example, a synchronization completion report, a BSR, an RRC message, information on the remaining data amount, and the like can be considered. In some cases, a plurality of control data is received.

  [Step S18] The UL resource allocation unit 152 determines whether the control data received in step S17 includes information on the remaining data amount. This can be determined based on, for example, an identifier included in the header portion of the received data. If the remaining data amount information is included, the process proceeds to step S19. If the remaining data amount information is not included, the process proceeds to step S20.

  [Step S19] The UL resource allocation unit 152 allocates an uplink radio resource having a size corresponding to the remaining data amount to the mobile station 200 as an uplink data channel. Then, UL resource allocation section 152 generates uplink radio resource allocation information. The transmission unit 160 transmits the generated allocation information to the mobile station 200 using the downlink control channel.

  [Step S20] The control unit 150 executes control processing according to the control data received in step S17. For example, when a BSR is received, an uplink radio resource having a size corresponding to the BSR is allocated to the mobile station 200 as an uplink data channel. When an RRC message is received, connection control such as initial connection, reconnection, and handover is performed according to the content of the RRC message. If it is determined in step S11 that there is transmission data, the transmission unit 160 transmits user data to the mobile station 200 via a downlink data channel.

  In this way, when the radio base station 100 receives the preamble signal through the random access channel, the radio base station 100 allocates an uplink radio resource of a predetermined size that does not depend on the random access occurrence factor to the mobile station 200. Then, a random access response including the allocation information is transmitted to the mobile station 200. Thereafter, the radio base station 100 receives control data using the allocated uplink radio resource, and executes a process according to the control data. At this time, if there is untransmitted control data in the mobile station 200, an uplink radio resource is additionally allocated.

  Note that the processing order of the timing measurement in step S14 and the resource allocation in step S15 may be reversed. In the above description, the allocation information is included in the random access response and transmitted. However, the allocation information may be transmitted at a different timing from the random access response. In the above description, the preamble number and the random access response are transmitted on the downlink data channel, but may be transmitted on the downlink control channel. Similarly, in the above description, the allocation information excluding the random access response is transmitted on the downlink control channel, but may be transmitted on the downlink data channel.

  FIG. 11 is a flowchart showing RA control of the mobile station. Here, consider a case where the mobile station 200 and the radio base station 100 perform radio communication. In the following, the process illustrated in FIG. 11 will be described in order of step number.

  [Step S <b> 21] The preamble generation unit 252 determines whether a preamble number has been received from the radio base station 100. As a case where individual preamble designation is received, for example, the start of downlink data communication or the handover can be considered. If a preamble number has been received, the process proceeds to step S22. If the preamble number has not been received, the process proceeds to step S23.

  [Step S22] The preamble generation unit 252 generates a preamble signal sequence individually designated by the radio base station 100. The transmission unit 260 transmits the generated preamble signal to the radio base station 100 using a random access channel. Thereafter, the process proceeds to step S26.

  [Step S23] The preamble generation unit 252 determines whether there is control data to be transmitted to the radio base station 100. For example, when control data is transmitted in a situation where an individual preamble is not specified, for example, at the time of initial connection or reconnection to the radio base station 100, at the start of uplink data transmission (the transmission of user data to the transmission buffer 240). Or when the control data generation unit 254 detects arrival). If there is control data to be transmitted, the process proceeds to step S24. If there is no control data to be transmitted, the process proceeds to step S21.

  [Step S24] The preamble generation unit 252 selects one preamble number that can be used by the mobile station 200 based on a random number. Then, the preamble generation unit 252 generates a preamble signal sequence of the selected number. The transmission unit 260 transmits the generated preamble signal to the radio base station 100 using a random access channel.

  [Step S25] The preamble generation unit 252 determines whether the random access in step S24 is successful. This can be determined based on whether or not a random access response is received from the radio base station 100 within a predetermined time. If the random access is successful, the process proceeds to step S26. If the random access fails, the process proceeds to step S21.

[Step S26] The timing correction unit 251 corrects the uplink timing based on the synchronization command included in the random access response received from the radio base station 100.
[Step S27] The control data generation unit 254 determines whether there is control data to be transmitted to the radio base station 100. If there is control data to be transmitted, the process proceeds to step S28. If there is no control data to be transmitted, the process proceeds to step S32. Note that the control data to be transmitted may be, for example, a BSR or RRC message. There may be a case where there are a plurality of control data to be transmitted. Further, since it may be necessary to transmit control data after the determination in step S23, it is conceivable that the determination result here is different from the determination result in step S23.

  [Step S28] The control data generation unit 254 compares the data amount of the control data to be transmitted with the allocation amount of the uplink radio resource based on the allocation information included in the random access response received from the radio base station 100. If the transmission amount is larger than the allocated amount, the process proceeds to step S29. If the transmission amount is less than or equal to the allocation amount, the process proceeds to step S31.

  [Step S29] The control data generation unit 254 selects control data to be transmitted first (for example, control data of an amount obtained by subtracting the information of the remaining data amount from the allocated amount). Further, the control data generation unit 254 generates information on the remaining data amount and adds it to the control data to be transmitted first. The transmission unit 260 transmits the control data to the radio base station 100 through the assigned uplink data channel.

  [Step S30] The transmission unit 260 transmits the remaining control data not selected in Step S29 to the radio base station 100 through an uplink data channel additionally allocated from the radio base station 100 after Step S29.

[Step S <b> 31] The transmission unit 260 transmits control data to the radio base station 100 through an uplink data channel assigned by the radio base station 100.
[Step S32] The control data generation unit 254 generates, as control data, a synchronization completion report indicating that the uplink timing correction has been completed. The transmission unit 260 transmits the generated synchronization completion report to the radio base station 100 using the uplink data channel allocated from the radio base station 100.

  [Step S <b> 33] The control unit 250 executes control processing according to the cause of random access. For example, when user data is received from the radio base station 100, ACK / NACK is generated. ACK / NACK is transmitted on the uplink data channel or the uplink control channel. In addition, when uplink radio resource allocation is received after transmitting the BSR, the user data held in the transmission buffer 240 is output. When an RRC message is transmitted, connection control such as initial connection, reconnection, and handover is performed.

  In this way, the mobile station 200 transmits the preamble signal selected by the individual preamble specified by the radio base station 100 or the random number through the random access channel. Then, a random access response including allocation information is received from the radio base station 100. After that, the mobile station 200 transmits control data using the allocated uplink radio resource having a fixed size. At this time, if there is no special control data to be transmitted, a synchronization completion report is transmitted. On the other hand, when there is more control data to be transmitted than the allocated amount, the remaining data amount information is also transmitted and received from the radio base station 100 for additional allocation.

In the above description, the synchronization completion report is transmitted when there is no other control data to be transmitted. However, the synchronization completion report may also be transmitted when there is other control data to be transmitted.
Next, a specific example of the flow of communication between the radio base station 100 and the mobile station 200 will be described.

FIG. 12 is a sequence diagram showing downlink data communication. In the following, the process illustrated in FIG. 12 will be described in order of step number.
[Step S41] When the user data to be transmitted to the mobile station 200 arrives, the radio base station 100 assigns an individual preamble number to the mobile station 200. Then, the radio base station 100 transmits the preamble number to the mobile station 200 through the downlink data channel.

  [Step S42] The mobile station 200 transmits the preamble signal having the preamble number specified in step S41 to the radio base station 100 using a random access channel. The allocation of individual preambles is valid for a predetermined time. For this reason, the mobile station 200 transmits a random access at a predetermined time after receiving the notification of the preamble number.

  [Step S43] The radio base station 100 measures the uplink communication timing based on the random access signal (preamble signal) received from the mobile station 200. In addition, an uplink radio resource (uplink data channel) having a predetermined size is allocated to the mobile station 200. Then, the radio base station 100 transmits a random access response including the synchronization command and the allocation information to the mobile station 200 through the downlink data channel.

  [Step S44] The mobile station 200 corrects the uplink timing based on the synchronization command included in the random access response. Then, the mobile station 200 transmits a synchronization completion report to the radio base station 100 using the uplink data channel indicated by the allocation information included in the random access response.

[Step S45] Upon receiving the synchronization completion report from the mobile station 200, the radio base station 100 transmits user data addressed to the mobile station 200 to the mobile station 200 via a downlink data channel.
[Step S46] The mobile station 200 transmits ACK / NACK to the radio base station 100 through the uplink data channel or the uplink control channel according to the reception status of the downlink data channel from the radio base station 100.

  In this way, when performing only downlink data communication from the radio base station 100 to the mobile station 200, the mobile station 200 transmits a synchronization completion report using the uplink radio resource assigned by the random access response. When receiving the synchronization completion report from the mobile station 200, the radio base station 100 can start downlink data transmission.

FIG. 13 is a sequence diagram showing uplink data communication. In the following, the process illustrated in FIG. 13 will be described in order of step number.
[Step S51] When user data to be transmitted to the radio base station 100 arrives, the mobile station 200 randomly selects a preamble number. Then, the mobile station 200 transmits a preamble signal having the selected preamble number to the radio base station 100 using a random access channel. Note that the non-individual preamble may collide with another mobile station such as the mobile station 200a. If transmission fails due to a collision, the mobile station 200 repeatedly transmits until it succeeds.

  [Step S52] The radio base station 100 measures the uplink communication timing based on the random access signal (preamble signal) received from the mobile station 200. In addition, an uplink radio resource (uplink data channel) having a predetermined size is allocated to the mobile station 200. Then, the radio base station 100 transmits a random access response including a synchronization command and allocation information to the mobile station 200 via the data channel.

  [Step S53] The mobile station 200 corrects the uplink timing based on the synchronization command included in the random access response. Then, the mobile station 200 transmits a BSR (data transmission request including a data amount) to the radio base station 100 on the uplink data channel indicated by the allocation information included in the random access response.

  [Step S <b> 54] The radio base station 100 allocates an uplink radio resource (uplink data channel) corresponding to the data amount indicated by the BSR received from the mobile station 200 to the mobile station 200. Then, the radio base station 100 transmits the allocation information to the mobile station 200 through the downlink control channel.

[Step S55] The mobile station 200 transmits user data to the radio base station 100 through the uplink data channel indicated by the allocation information received from the radio base station 100.
[Step S56] The radio base station 100 transmits ACK / NACK to the mobile station 200 through the downlink data channel according to the reception status of the uplink data channel from the mobile station 200.

  In this way, when performing only uplink data communication from the mobile station 200 to the radio base station 100, the mobile station 200 transmits the BSR using the uplink radio resource assigned by the random access response. When receiving the BSR from the mobile station 200, the radio base station 100 allocates an uplink radio resource having a size corresponding to the BSR to the mobile station 200. Thereafter, the mobile station 200 can start uplink data transmission.

FIG. 14 is a first sequence diagram showing uplink and downlink data communication. In the following, the process illustrated in FIG. 14 will be described in order of step number.
[Step S61] When user data to be transmitted to the mobile station 200 arrives, the radio base station 100 assigns an individual preamble number to the mobile station 200. Then, the radio base station 100 transmits the preamble number to the mobile station 200 through the downlink data channel.

[Step S62] The mobile station 200 transmits the preamble signal having the preamble number specified in step S61 to the radio base station 100 using a random access channel.
[Step S63] The radio base station 100 measures the uplink communication timing based on the random access signal (preamble signal) received from the mobile station 200. In addition, an uplink radio resource (uplink data channel) having a predetermined size is allocated to the mobile station 200. Then, the radio base station 100 transmits a random access response including the synchronization command and the allocation information to the mobile station 200 through the downlink data channel.

  [Step S64] The mobile station 200 corrects the uplink timing based on the synchronization command included in the random access response. Here, the mobile station 200 detects that user data to be transmitted to the radio base station 100 has arrived, and transmits the BSR to the radio base station 100 on the uplink data channel indicated by the allocation information included in the random access response. To do. This BSR also serves as a synchronization completion report.

  [Step S <b> 65] The radio base station 100 allocates an uplink radio resource (uplink data channel) corresponding to the data amount indicated by the BSR received from the mobile station 200 to the mobile station 200. Then, the radio base station 100 transmits the allocation information to the mobile station 200 through the downlink control channel.

  [Step S66] Upon receiving the BSR from the mobile station 200, the radio base station 100 transmits user data addressed to the mobile station 200 to the mobile station 200 through a downlink data channel. That is, the radio base station 100 determines that the uplink timing correction is completed by receiving the BSR.

  [Step S67] The mobile station 200 transmits ACK / NACK to the radio base station 100 through the uplink data channel or the uplink control channel according to the reception status of the downlink data channel from the radio base station 100.

[Step S68] The mobile station 200 transmits user data to the radio base station 100 through the uplink data channel indicated by the allocation information received in Step S65.
[Step S69] The radio base station 100 transmits ACK / NACK to the mobile station 200 through the downlink data channel according to the reception status of the uplink data channel from the mobile station 200.

  In this way, when uplink data communication from the mobile station 200 to the radio base station 100 is also performed at the start of downlink data communication from the radio base station 100 to the mobile station 200, the mobile station 200 performs random transmission during downlink data communication. The BSR is transmitted using the uplink radio resource allocated by the access response. When receiving the BSR from the mobile station 200, the radio base station 100 allocates an uplink radio resource having a size corresponding to the BSR to the mobile station 200. Thereby, the radio base station 100 can start downlink data transmission, and the mobile station 200 can start uplink data transmission.

  It should be noted that the message related to the uplink data communication and the message related to the downlink data communication after step S65 can be transmitted and received independently, and the transmission order may be different from the above. For example, the radio base station 100 can start transmission of downlink user data after receiving uplink user data, or can perform resource allocation for reception of uplink user data after transmission of downlink user data is completed.

  Also, the mobile station 200 can transmit the ACK / NACK in step S67 described above together with the user data in step S68 on the same uplink data channel. In the above example, the BSR is transmitted using the uplink radio resource allocated at the start of downlink data communication (the transmission of uplink user data is started). However, an RRC message may be transmitted instead of the BSR or together with the BSR. Is possible.

FIG. 15 is a second sequence diagram showing uplink and downlink data communication. In the following, the process illustrated in FIG. 15 will be described in order of step number.
[Step S71] When user data to be transmitted to the radio base station 100 arrives, the mobile station 200 randomly selects a preamble number. Then, the mobile station 200 transmits a preamble signal having the selected preamble number to the radio base station 100 using a random access channel.

  [Step S72] When the mobile station 200 detects that the random access signal transmission in step S71 has failed due to a collision with another mobile station such as the mobile station 200a, the mobile station 200 transmits a preamble signal having the preamble number selected in step S71. Resend. At this time, the mobile station 200 retransmits at an appropriate interval from the previous transmission in order to reduce the probability of collision again. When the transmission interval is designated from the radio base station 100, the retransmission is performed after the designated interval.

  [Step S <b> 73] When the user data to be transmitted to the mobile station 200 arrives, the radio base station 100 allocates an individual preamble number to the mobile station 200. Then, the radio base station 100 transmits the preamble number to the mobile station 200 through the downlink data channel.

[Step S74] If the random access is not yet successful after step S72, the mobile station 200 changes the preamble number selected in step S71 to the preamble number specified in step S73, and wirelessly transmits a preamble signal corresponding to the preamble number. Transmit to the base station 100.

  [Step S75] The radio base station 100 measures the uplink communication timing based on the random access signal (preamble signal) received from the mobile station 200. In addition, an uplink radio resource (uplink data channel) having a predetermined size is allocated to the mobile station 200. Then, the radio base station 100 transmits a random access response including the synchronization command and the allocation information to the mobile station 200 through the downlink data channel.

  [Step S76] The mobile station 200 corrects the uplink timing based on the synchronization command included in the random access response. Then, the mobile station 200 transmits the BSR to the radio base station 100 using the uplink data channel indicated by the allocation information included in the random access response. This BSR also serves as a synchronization completion report.

  [Step S77] The radio base station 100 allocates an uplink radio resource (uplink data channel) corresponding to the data amount indicated by the BSR received from the mobile station 200 to the mobile station 200. Then, the radio base station 100 transmits the allocation information to the mobile station 200 through the downlink control channel.

[Step S78] The mobile station 200 transmits user data to the radio base station 100 through an uplink data channel indicated by the allocation information received from the radio base station 100.
[Step S79] The radio base station 100 transmits ACK / NACK to the mobile station 200 through the downlink data channel according to the reception status of the uplink data channel from the mobile station 200.

[Step S80] The radio base station 100 transmits user data addressed to the mobile station 200 to the mobile station 200 through a downlink data channel.
[Step S81] The mobile station 200 transmits ACK / NACK to the radio base station 100 through the uplink data channel or the uplink control channel according to the reception status of the downlink data channel from the radio base station 100.

  In this way, when the random access from the mobile station 200 to the radio base station 100 fails, if the individual preamble is designated from the radio base station 100, the mobile station 200 is designated the preamble signal to be transmitted. Change to Then, the mobile station 200 transmits the BSR using the allocated uplink radio resource. Thereby, the radio base station 100 can start downlink data transmission, and the mobile station 200 can start uplink data transmission.

  It should be noted that the message related to the uplink data communication and the message related to the downlink data communication after step S77 can be transmitted / received independently, and the transmission order may be different from the above. For example, the radio base station 100 can perform resource allocation for reception of uplink user data after transmission of downlink user data is completed. In the above example, the BSR is transmitted using the uplink radio resource (the transmission of the uplink user data is started), but it is also possible to transmit the RRC message instead of the BSR or together with the BSR.

  Further, the transmission in step S74 may be performed at the timing when the transmission interval in steps S71 and S72 (for example, the transmission interval designated from the radio base station 100) is taken over, or is irrelevant to the transmission interval in steps S71 and S72. It may be performed at the timing. In step S72, the preamble of the first selected preamble number is used. However, the preamble number may be selected again at random.

  FIG. 16 is a sequence diagram illustrating the handover process. Here, consider a case where the mobile station 200 performs handover from the radio base station 100 a to the radio base station 100. In the following, the process illustrated in FIG. 16 will be described in order of step number.

  [Step S91] When the radio base station 100a determines that a handover to the radio base station 100 is necessary, the radio base station 100a transmits a preamble number to the mobile station 200 via a downlink data channel. For example, the preamble number is assigned to the mobile station 200 by the radio base station 100 upon receiving a handover start notification from the radio base station 100a.

[Step S92] The mobile station 200 transmits the preamble signal having the preamble number specified in Step S91 to the radio base station 100 using a random access channel.
[Step S93] The radio base station 100 measures the uplink communication timing based on the random access signal (preamble signal) received from the mobile station 200. In addition, an uplink radio resource (uplink data channel) having a predetermined size is allocated to the mobile station 200. Then, the radio base station 100 transmits a random access response including the synchronization command and the allocation information to the mobile station 200 through the downlink data channel.

  [Step S94] The mobile station 200 corrects the uplink timing based on the synchronization command included in the random access response. Here, the mobile station 200 detects that the data amount of the RRC message to be transmitted is larger than the allocated amount, and transmits a part of the RRC message and information on the remaining data amount to the radio base station 100 on the allocated uplink data channel. Send.

  [Step S <b> 95] The radio base station 100 allocates an uplink radio resource (uplink data channel) to the mobile station 200 based on the remaining data amount information received from the mobile station 200. Then, the radio base station 100 transmits the allocation information to the mobile station 200 through the downlink control channel.

[Step S96] The mobile station 200 transmits the remainder of the RRC message to the radio base station 100 with the allocation information received from the radio base station 100 being an uplink data channel.
In this way, when the mobile station 200 performs handover from the radio base station 100a to the radio base station 100, the preamble signal of the preamble number received from the handover source radio base station 100a is transmitted to the handover destination radio base station 100. Send. Thereafter, the mobile station 200 transmits an RRC message to the radio base station 100.

  Here, the mobile station 200 transmits a part of the RRC message and information on the remaining data amount in the radio resource allocated by the random access response, and then uses the uplink radio resource additionally allocated to transmit the rest of the RRC message. Send. As described above, control data having a large data amount (for example, control data having a data amount larger than the BSR) like the RRC message at the time of handover can be smoothly transmitted to the radio base station 100.

  According to the radio communication system as described above, uplink radio resources are allocated to the mobile stations 200 and 200a even in random access for the purpose of timing synchronization in downlink data communication. For this reason, when the control data to be transmitted is generated, the mobile stations 200 and 200a can divert the uplink radio resource allocated by the random access response, and need not perform random access separately. In particular, since resource allocation can be performed using individually assigned preambles, it is possible to avoid an access collision that occurs when a preamble selected by a random number is used.

  The radio base stations 100 and 100a receive some control data (synchronization completion report or other type of control data transmitted instead of the synchronization completion report) from the mobile stations 200 and 200a after the random access response, It can be surely known at an early stage that the uplink timing synchronization is completed. For this reason, subsequent communication (for example, downlink data transmission) can be started at an earlier timing.

  In addition, the radio base stations 100 and 100a allocate a fixed-size uplink radio resource that is independent of the cause of random access, thereby reducing the processing load of random access. In this case, the mobile stations 200 and 200a can receive additional allocation of uplink radio resources by adding information on the remaining data amount. For this reason, for example, even when the allocation size at the time of random access is fixed to about the data amount of the BSR, the RRC message at the time of handover in which the data amount tends to be larger than the BSR can be smoothly transmitted.

  The random access control described above can also be applied to a wireless communication system having a system configuration different from that shown in FIG. Further, the present invention can be applied to a wireless communication system having a multiplex communication method, a multiple access method, and a channel configuration different from those shown in FIGS.

  In the above wireless communication system, a fixed-size uplink wireless lease that is independent of the cause of random access is allocated, but the allocated size may not be completely unified. For example, there may be a difference in allocation size between individually assigned preamble signals and randomly selected non-individual preamble signals. In the above wireless communication system, various control data can be transmitted in the uplink radio resource specified by the random access response. However, uplink user data may be transmitted together with the control data.

Regarding the above embodiment, the following additional notes are disclosed.
(Supplementary note 1) A radio base station that designates a random access signal to the mobile station and receives the designated random access signal from the mobile station when performing downlink data transmission to the mobile station,
A transmission unit for transmitting timing adjustment information based on the reception result of the random access signal and allocation information of uplink radio resources used for transmission of control data by the mobile station to the mobile station;
A radio base station characterized by comprising:

  (Additional remark 2) The said transmission part transmits the allocation information of the uplink radio resource of the same size as the time of downlink data transmission to the said mobile station at the time of a handover, The radio base station of Additional description 1 characterized by the above-mentioned.

  (Additional remark 3) The said transmission part transmits the allocation information of the uplink radio resource of the same size as the time of downlink data transmission to the said mobile station in the case of the reconnection request | requirement from the said mobile station, The additional note 1 characterized by the above-mentioned. The radio base station described.

  (Additional remark 4) The said transmission part makes the allocation size of an uplink radio resource the same about all the allocation information transmitted to the said mobile station in response to reception of the designated random access signal, The additional description 1 characterized by the above-mentioned. Wireless base station.

(Additional remark 5) It further has a receiving part which receives a data transmission request from the mobile station as the control data,
The transmitting unit transmits uplink radio resource allocation information corresponding to the data transmission request received by the receiving unit to the mobile station;
The radio base station according to supplementary note 1, wherein:

(Supplementary note 6) The radio base station according to supplementary note 1, further comprising a reception unit that receives a synchronization completion report from the mobile station as the control data.
(Additional remark 7) It further has the receiving part which receives the said control data containing the information of remaining data amount,
The transmitter transmits uplink radio resource allocation information according to the remaining data amount received by the receiver to the mobile station;
The radio base station according to supplementary note 1, wherein:

(Supplementary Note 8) A mobile station that receives a designation of a random access signal from a radio base station when transmitting downlink data, and transmits the designated random access signal to the radio base station,
A reception unit that receives timing adjustment information based on a reception result of the random access signal in the radio base station, and uplink radio resource allocation information from the radio base station;
A transmission unit that transmits control data to the radio base station using an uplink radio resource indicated by the allocation information received by the reception unit;
A mobile station characterized by comprising:

(Supplementary note 9) The mobile station according to supplementary note 8, wherein the transmission unit transmits a data transmission request as the control data.
(Supplementary note 10) The mobile station according to supplementary note 8, wherein the transmission unit transmits a synchronization completion report based on the timing adjustment information received by the reception unit as the control data.

(Supplementary note 11) The mobile station according to supplementary note 10, wherein the transmission unit omits transmission of the synchronization completion report when there is control data to be transmitted in addition to the synchronization completion report.
(Supplementary note 12) The mobile station according to Supplementary note 8, wherein the transmission unit transmits a plurality of types of control data using uplink radio resources indicated by the allocation information.

  (Supplementary note 13) The movement according to Supplementary note 8, wherein the transmission unit transmits information including information on a remaining data amount when an uplink radio resource allocation size indicated by the allocation information is smaller than a control data amount to be transmitted. Bureau.

(Supplementary note 14) The mobile station according to supplementary note 13, wherein the transmission unit includes header information indicating that the remaining data amount information is included in the control data.
(Supplementary Note 15) When the radio base station performs downlink data transmission to the mobile station, it designates a random access signal to the mobile station,
The mobile station transmits a designated random access signal to the radio base station;
The radio base station transmits timing adjustment information based on the reception result of the random access signal and uplink radio resource allocation information used for transmission of control data by the mobile station to the mobile station,
A communication method characterized by the above.

(Supplementary Note 16) When the mobile station performs uplink data transmission to the radio base station, the mobile station transmits a non-individual random access signal not designated by the radio base station to the radio base station,
When the radio base station performs downlink data transmission to the mobile station, the mobile station specifies an individual random access signal,
When the mobile station fails to transmit the non-individual random access signal, the mobile station transmits the individual random access signal instead of the non-individual random access signal to the radio base station,
The radio base station transmits timing adjustment information based on the reception result of the individual random access signal and uplink radio resource allocation information to the mobile station.
A communication method characterized by the above.

  (Supplementary note 17) The communication method according to supplementary note 16, wherein the mobile station transmits a data transmission request using an uplink radio resource indicated by the allocation information received from the radio base station.

1 radio base station 1a receiver 1b transmitter 2 mobile station 2a receiver 2b transmitter

Claims (4)

A base station and a mobile station,
When the first event occurs, the mobile station transmits an individual random access signal designated by the base station to the base station, and a first random access procedure for synchronizing uplink and a second event occurs. A second random access procedure for synchronizing uplink by transmitting a non-individual random access signal selected by the mobile station to the base station, and the individual random access signal from the base station If not specified, the non-individual random access signal is not transmitted ,
The base station transmits a response signal including uplink radio resource allocation information to the mobile station by any of the first random access procedure and the second random access procedure.
Wireless communication system. A transmitter for transmitting a signal to the base station;
When a first event occurs, a first random access procedure for synchronizing uplink by transmitting an individual random access signal designated by the base station from the transmitter to the base station, and a second event has occurred. A non-individual random access signal selected by the local station is transmitted from the transmitting unit to the base station, and a second random access procedure for synchronizing uplinks can be executed. A control unit that controls not to transmit the non-individual random access signal from the transmission unit when an access signal is specified ;
A receiving unit that receives a response signal including uplink radio resource allocation information from the base station by any of the first random access procedure and the second random access procedure;
A mobile station comprising: A base station,
When a first event occurs, a first random access procedure for synchronizing uplink by transmitting an individual random access signal designated by the base station to the base station; and when a second event occurs, the mobile station A second random access procedure for synchronizing uplink by transmitting a non-individual random access signal to be selected to the base station , and when the individual random access signal is designated from the base station, from the mobile station not to transmit the non-dedicated random access signal, a receiving unit that receives the individual random access signal or said non-dedicated random access signal,
A transmission unit that transmits a response signal including uplink radio resource allocation information to the mobile station by any of the first random access procedure and the second random access procedure;
A base station comprising: A mobile station that transmits a random access preamble in response to an instruction from a base station,
When there is an instruction of the random access preamble from the base station, transmission control of the random access preamble and the other random access preamble is performed so as not to transmit another random access preamble that is not based on the instruction from the base station. A transmitter that performs
A receiving unit that receives a response signal including uplink radio resource allocation information from the base station by any transmission of the random access preamble and the other random access preambles;
A mobile station comprising:

Images