JP2009081685A - Mobile communication system, base station device, mobile station device, and random access method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently perform transmission and reception of a random access response message. <P>SOLUTION: In a radio communication system, a mobile station device comprises: a random access transmission section for transmitting a signal of random access; a random access response extraction section for extracting random access response information to the mobile station device from a reception signal; a random access response end detection section for detecting the transmission end of the random access response information; and a retransmission processing section which instructs retransmission to the random access transmission section when the transmission end is detected before the random access response information to the mobile station device is extracted. Also in the system, a base station device comprises: a random access detection section for detecting a signal of random access; a control data generation section for generating random access response information of detected random access and information capable of determining the transmission end; and a signal arrangement section for arranging the generated information in a transmission signal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a radio communication system, a base station apparatus, a mobile station apparatus, and a random access method, and more particularly to a base station apparatus, a mobile station apparatus, and a random access method that perform random access in an uplink from the mobile station apparatus to the base station apparatus. .

In 3GPP (3rd Generation Partnership Project), the W-CDMA system is standardized as a 3rd generation cellular mobile communication system, and services are started sequentially. In addition, HSDPA (High Speed Downlink Packet Access), which further increases the communication speed, has been standardized and the service has started.
On the other hand, in 3GPP, the evolution of third generation radio access (Evolved Universal Terrestrial Radio Access; hereinafter referred to as “EUTRA”) is being studied. An OFDM (Orthogonal Frequency Division Multiplexing) system has been proposed as a downlink of EUTRA. In addition, a single carrier communication scheme of DFT (Discrete Fourier Transform) -spread OFDM scheme has been proposed as an uplink of EUTRA.

FIG. 20 is a diagram illustrating uplink and downlink channel configurations of EUTRA. The downlink from the base station apparatus to the three mobile station apparatuses includes a downlink pilot channel DPiCH (Downlink Pilot Channel), a downlink synchronization channel DSCH (Downlink Synchronization Channel), a downlink shared channel PDSCH (Physical Downlink Shared Channel), a downlink It is composed of a link control channel PDCCH (Physical Downlink Control Channel) and a common control channel CCPCH (Common Control Physical Channel).
The uplink from the mobile station apparatus to the base station apparatus includes an uplink pilot channel UPiCH (Uplink Pilot Channel), a random access channel RACH (Random Access Channel), an uplink shared channel PUSCH (Physical Uplink Shared Channel), and an uplink control channel. It is comprised by PUCCH (Physical Uplink Control Channel) (refer nonpatent literature 1, 2).

  FIG. 21 is a diagram illustrating an example of an uplink radio resource configuration of EUTRA. In the diagram shown in FIG. 21, the horizontal axis represents time, and the vertical axis represents frequency. FIG. 21 shows the configuration of one radio frame, and this radio frame is divided into a plurality of resource blocks. In this example, the resource block is configured with an area of 1.25 MHz in the frequency direction and 1 ms in the time direction as units, and the random access channel RACH and the uplink shared channel PUSCH described in FIG. The uplink control channel PUCCH is allocated as shown in the figure. That is, resource blocks to which the random access channel RACH is allocated are indicated by hatched areas, resource blocks to which the uplink shared channel PUSCH is allocated are indicated by blank areas, and resource blocks to which the uplink control channel PUCCH is allocated are indicated by horizontal lines. Shown in hatched area.

  The uplink random access channel RACH of EUTRA includes an asynchronous random access channel and a synchronous random access channel. As a minimum unit of the asynchronous random access channel, a 1.25 MHz band is used. The base station apparatus prepares a plurality of channels for random access and supports access from a large number of mobile station apparatuses. The largest use purpose of the asynchronous random access channel is to synchronize the uplink mobile station apparatus and the base station apparatus. In addition, several bits of information such as a scheduling request for allocating radio resources are also asynchronous random. It is also possible to shorten the connection time by transmitting using the access channel. The purpose of using the synchronous random access is to make a scheduling request of the mobile station apparatus synchronized with the uplink (for example, Non-Patent Document 2).

  Asynchronous random access has two access methods, contentioned based Random Access and non-contentioned based Random Access, and contention random access may collide between mobile station devices. This is random access with a random access, which is normally performed. Non-contention random access is a random access in which no collision occurs between mobile station devices, and is performed by the base station device in a special case such as a handover in order to quickly synchronize between the mobile station device and the base station device. Is called.

In asynchronous random access, only the preamble is transmitted for synchronization. This is proved as a random access preamble. This preamble includes a signature that is a signal pattern representing information. By preparing dozens of types of signatures and selecting and using them, several bits of information (hereinafter referred to as “signature ID”) can be expressed. Currently, EUTRA transmits 6-bit information by signature. For these 6 bits, 64 signatures of 2 6 are prepared.
Random ID is assigned to 5 bits out of 6 bits by the signature, and any information such as the reason for random access, downlink path loss / CQI (Channel Quality Indicator) is assigned to the remaining 1 bit (Non-patent Document 3) reference).

  FIG. 22 is a sequence diagram illustrating a procedure example of contention random access of asynchronous random access. First, the mobile station apparatus selects a signature corresponding to a signature ID including a random ID, downlink path loss / CQI information, and the like, and transmits a random access preamble using an asynchronous random access channel (message Ma1). When the base station apparatus receives the preamble from the mobile station apparatus, the base station apparatus calculates a synchronization timing shift between the mobile station apparatus and the base station apparatus from the preamble, generates synchronization timing shift information, and generates an L2 / L3 (Layer2 / Layer3) message. Scheduling information is generated, and intra-cell mobile station temporary identification information (Temporally Cell-Radio Network Temporally Identity: Temporarily C-RNTI) is assigned.

  The base station apparatus uses random access identification information (Random) indicating that a random access response, which is a response addressed to the mobile station apparatus that has transmitted a preamble to the random access channel, is allocated to the downlink shared channel PDSCH. Access-Radio Network Temporally Identity (RA-RNTI) and the position of the resource block of the downlink shared channel PDSCH in which the random access response is inserted and the data size of the random access response are arranged. Further, the base station device uses the resource block of the downlink shared channel PDSCH that has notified the arrangement of the random access response using the random access identification information RA-RNTI, the synchronization timing deviation information, the scheduling information, and the intra-cell mobile station temporary identification. A random access response including the information and the signature ID (or random ID) of the received preamble is transmitted (message Ma2). The random access identification information RA-RNTI is a specific value that is not used as the intra-cell mobile station identification information, and the mobile station apparatus detects the specific value so that the random access response is transmitted to the downlink shared channel. It is identified that it is located on the PDSCH. The random access identification information RA-RNTI is prepared corresponding to the number of resource blocks that are physical resources of the asynchronous random access channel. That is, when there are m asynchronous random access channels on the frequency axis, m random access identification information RA-RNTI exists.

  FIG. 23A is an example of arrangement of the random access identification information RA-RNTI, the random access response scheduling information, and the random access response size described above on the downlink control channel PDCCH. FIG. 23B is an example of arrangement of the random access response on the downlink shared channel PDSCH when the arrangement is notified by the random access identification information RA-RNTI of asynchronous random access. As shown in FIG. 23, when the random access response arrangement is notified by the random access identification information RA-RNTI arranged in the downlink control channel PDCCH, the number of signature IDs (or random numbers) is assigned to the downlink shared channel PDSCH. Random access including a random access response message composed of synchronization timing shift information, scheduling information, intra-cell mobile station temporary identification information, and received preamble signature ID for a plurality of mobile station apparatuses indicated by the number of IDs) and the number of signature IDs Response is placed. Furthermore, the random access response can be divided into a plurality of times, and can be arranged at different time / frequency positions of the downlink shared channel PDSCH. The same RA-RNTI is also used when dividing such a random access response message into a plurality of pieces (see Non-Patent Document 4).

  When the mobile station apparatus confirms that the downlink control channel PDCCH has the random access identification information RA-RNTI, the mobile station apparatus confirms the content of the random access response arranged in the downlink shared channel PDSCH, and transmits the signature ID ( Alternatively, a response including a random ID) is extracted, and the synchronization shift is corrected based on the synchronization timing shift information in the response. Next, based on the received scheduling information, the mobile station apparatus transmits an L2 / L3 message including at least intra-cell mobile station identification information (or intra-cell mobile station temporary identification information) in the scheduled resource block (message Ma3). When the base station apparatus receives the L2 / L3 message from the mobile station apparatus, the base station apparatus transmits contention resolution for determining whether or not a collision occurs between the mobile station apparatuses to the mobile station apparatus (message Ma4) ( (Refer nonpatent literature 3).

  In the random access response (message Ma2) and the contention resolution (message Ma4), the transmission period Tma2_NB of the base station device (or the reception period Tma2_UE = Tma2_NB of the mobile station device) and the transmission period Tma4_NB of the base station device, respectively. (Or the mobile station apparatus reception period Tma4_UE = Tma4_NB) is determined, and if the mobile station apparatus cannot receive a random access response message or contention resolution addressed to the mobile station within each period, random access If the procedure fails, the procedure returns to the procedure of transmitting from the random access preamble (message Ma1) again.

  FIG. 24 is a sequence diagram illustrating a procedure example of non-contention random access of asynchronous random access. First, the base station apparatus selects a signature ID and transmits a random access preamble assignment including this signature ID to the mobile station apparatus (message Mb1). The mobile station apparatus transmits a random access preamble using an asynchronous random access channel using a signature ID included in the random access preamble from the base station apparatus (message Mb2). When the base station apparatus receives the preamble from the mobile station apparatus, the base station apparatus calculates a synchronization timing shift between the mobile station apparatus and the base station apparatus from the preamble and generates synchronization timing shift information. As shown in FIG. 25 (a), the base station apparatus sends a random access response to the mobile station apparatus that has transmitted a preamble to the downlink control channel PDCCH using a random access channel, as shown in FIG. 25 (b). Random access identification information RA-RNTI indicating that is allocated to the downlink shared channel PDSCH, scheduling information indicating the position of the resource block of the downlink shared channel PDSCH in which the random access response is inserted, and random access Random access response size indicating response data size is arranged.

  Referring back to FIG. 24, the base station apparatus further uses the RA-RNTI resource block of the downlink shared channel PDSCH that has notified the arrangement of the random access response, synchronization timing deviation information, received preamble signature ID, etc. Is transmitted (message Mb3). FIG. 25B shows an example of arrangement of this random access response on the downlink shared channel PDSCH. Upon confirming that the downlink control channel PDCCH has RA-RNTI, the mobile station apparatus confirms the content of the random access response arranged in the downlink shared channel PDSCH and transmits the signature ID (or random ID) of the transmitted preamble. Is extracted, and the synchronization shift is corrected based on the synchronization timing shift information in the response. In the random access response (message Mb3), a transmission period Tmb2_NB of the base station apparatus (or a reception period Tmb2_UE = Tmb2_NB of the mobile station apparatus) is defined, and the mobile station apparatus receives a random address addressed to the mobile station within that period. If the access response cannot be received, it is determined that the random access procedure has failed, and the procedure returns to the procedure for transmitting the random access preamble (message Mb2) again.

In addition, as shown in FIG. 26, the random response information of the response to the contention random access and the random access response information of the response to the non-contention random access can be included in one random access response and transmitted. FIG. 26A shows a state in which random access identification information RA-RNTI, scheduling information, and random access response size are arranged in the downlink control channel PDCCH. FIG.26 (b) shows a mode that the random access response notified by the information shown to Fig.26 (a) is arrange | positioned to downlink shared channel PDSCH. The signature ID number 1 indicates the number of signature IDs for contention random access, and the signature ID number 2 indicates the number of signature IDs for non-contention random access. The content of the random access information with the signature ID number 1 is the same as that shown in FIG. 23B for the competitive random access, and the content of the random access information with the signature ID number 2 is the same as that shown in FIG. It is the same as shown in.
3GPP TS (Technical Specification) 36.211, V1.10 (2007-05), Technical Specification Group Radio Access Network, Physical Channel and Mudulation (Release 8) 3GPP TS (Technical Specification) 36.212, V1.20 (2007-05), Technical Specification Group Radio Access Network, Multiplexing and channel coding (Release 8) R2-072338 “Update on Mobility, Security, Random Access Procedure, etc”, 3GPP TSG RAN WG2 Meeting # 58 Kobe, Japan, 7-11 May, 2007 R2-071617 “On setting the C-RNTI in RACH message two”, 3GPP TSG RAN WG2 Meeting # 58 Kobe, Japan, 7-11 May, 2007

  However, for example, the random access response (message Ma2) in the contention random access in the conventional asynchronous random access is divided for each random access response information up to a predetermined maximum number, and a plurality of different time / frequency of the downlink shared channel PDSCH. Therefore, the mobile station apparatus is random during the transmission period Tma2_NB of the base station apparatus (or the reception period Tma2_UE of the mobile station apparatus) unless receiving the random access response information addressed to the mobile station. You have to wait for access response information.

  FIG. 27 shows an outline of the uplink resource configuration of EUTRA in the upper stage, and shows an outline of the downlink resource structure in the lower stage. The horizontal axis of both represents time, and the vertical axis represents frequency. In this case, the origins of both time axes are matched. In the uplink resource configuration, an area hatched with dots indicates a resource block to which a random access channel RACH is allocated. In the illustrated example, this RACH is allocated to every fourth resource block. It is assumed that the base station transmission time Tma2_NB (or mobile station reception period Tma2_UE) corresponds to 10 resource block intervals. The mobile station apparatus transmits a random access preamble to the base station apparatus through one random access channel RACH, and the base station apparatus then uses the resource block of the downlink shared channel PDSCH to send a random access response at intervals of two resource blocks. Suppose that the mobile station apparatus fails to receive the random access response. As shown in FIG. 27, when the transmission period Tma2_NB of the base station apparatus is long, the mobile station apparatus that has failed in random access preamble transmission (message Ma1) or has failed to receive the random access response (message Ma2) as described above. The mobile station apparatus transmits the random access preamble again after the transmission period Tma2_NB, and there is a problem that it takes too much time until re-random access.

  The present invention has been made in view of such circumstances, and the object thereof is a base station device, mobile station device, wireless communication system, program, random access response transmission method, and transmission / reception device that efficiently transmits and receives random access responses. It is to provide a random access response receiving method.

  The present invention has been made to solve the above-described problems, and a radio communication system according to the present invention includes a base station apparatus and a plurality of mobile station apparatuses, wherein the mobile station apparatus includes the base station apparatus. Random access transmitter that transmits a random access signal to the station device and random access response information that is the response of the random access transmitted by the mobile station device is detected from the random access response information in the received signal. A random access response extraction unit for extracting, and a random access response end detection unit for detecting the end of transmission of random access response information during a transmission period of random access response information of a response to the random access transmitted by the mobile station device And the mobile station device transmitted During the transmission period of random access response information for response to random access, when the random access response end detection unit detects the end of transmission before the random access response extraction unit detects the response, the random access transmission A retransmission processing unit that instructs the unit to retransmit the random access signal, and the base station apparatus detects a random access signal from the received signal, and detects the detected signal. A control data generating unit that generates random access response information for random access and information capable of determining the end of transmission of random access response information during a transmission period of random access response information including the random access response information; run Characterized by comprising a signal arranging unit for arranging the determinable information to the transmission signal to the transmission end and the arm access response information.

  Further, the wireless communication system of the present invention is the above-described wireless communication system, wherein the information capable of determining the end of transmission is from a signal region in which random access response information is arranged together with the information during the transmission period. It is a flag indicating whether or not random access response information is arranged in a later signal area.

  The wireless communication system of the present invention is the above-described wireless communication system, wherein the information capable of determining the end of transmission is a signal region in which random access response information is arranged together with the information during the transmission period. It is the information showing the number of random access response information arrange | positioned in the signal area | region after this signal area | region to include.

  The wireless communication system of the present invention is any one of the wireless communication systems described above, wherein the random access is a non-contention random access in which the mobile station device transmits a signal according to the determination of the base station device. 4. The wireless communication system according to claim 1, further comprising: contention random access in which the mobile station device transmits a signal determined by the mobile station device. 5.

  Further, the mobile station apparatus of the present invention includes: a random access transmission unit that transmits a random access signal to the base station apparatus; and the random access response information transmitted from the random access response information in the received signal. Random access response information in a transmission period of a random access response information of a response to the random access transmitted by the mobile station apparatus, and a random access response extraction unit that detects and extracts random access response information that is an access response During the transmission period of the random access response end detection unit for detecting the end of transmission and the random access response information of the response to the random access transmitted by the mobile station apparatus, before the random access response extraction unit detects the response , When serial random access response end detection unit detects the end of transmission is characterized by comprising a retransmission processing section for instructing retransmission of the signal of the random access to the random access transmission unit.

  Further, the base station apparatus of the present invention is a response to a random access detection unit for detecting a random access signal from a received signal and a random access of the detected signal in a base station apparatus communicating with a plurality of mobile station apparatuses. A control data creation unit that generates random access response information and information capable of determining the end of transmission of random access response information during the transmission period of random access response information including the random access response information, and the generated random access response And a signal arrangement unit that arranges information and information capable of determining the end of transmission in a transmission signal.

  The random access method of the present invention is a random access method in a radio communication system comprising a base station apparatus and a plurality of mobile station apparatuses, wherein the mobile station apparatus transmits a random access signal to the base station apparatus. A first process of transmitting; a second process in which the base station apparatus detects the random access signal from a received signal received from the mobile station apparatus; and the base station apparatus in the second process. Generating random access response information for the random access of the signal detected in the step, and information capable of determining the end of transmission of the random access response information during the transmission period of the random access response information including the random access response information. Process and the random access generated by the base station device in the third process. A fourth step of transmitting a response signal and information capable of determining the end of transmission in a transmission signal, and a random number in a received signal when the mobile station apparatus receives the transmission signal of the fourth step. A fifth step of detecting and extracting random access response information, which is a response of the random access transmitted by the mobile station device in the first step, from the access response information, and the mobile station device Detecting from the received signal information capable of determining the end of transmission of the random access response information during the transmission period of the random access response information of the response to the random access transmitted by the mobile station device in the first process, A sixth step of detecting the end of transmission of random access response information during a transmission period; and In the transmission process of the random access response information of the response to the random access transmitted by the mobile station device in the process of step S5, the response is detected in the sixth process before the response is detected in the fifth process. And a seventh step of instructing retransmission of the random access signal when the end is detected.

  According to the present invention, the base station apparatus notifies the information capable of determining the end of transmission of the random access response information, and the mobile station apparatus detects the information capable of determining the end of transmission, thereby transmitting the transmitted random access preamble. Waiting for the end of the transmission period of the random access response when random access fails, such as when the mobile station device does not receive the random access response transmitted by the base station device or when the random access response transmitted by the base station device is not received by the mobile station device Since the failure can be recognized and random access can be performed again, the time until the random access is performed again can be shortened, and the random access response can be efficiently transmitted and received.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. The wireless communication system in the present embodiment includes a base station device 1 and a plurality of mobile station devices 2. The downlink from the base station apparatus 1 to the mobile station apparatus 2 is transmitted using the OFDM scheme, and the downlink pilot channel DPiCH, the downlink synchronization channel DSCH, the downlink shared channel PDSCH, the downlink control channel PDCCH, and the common control channel CCPCH. It is comprised by. The uplink from the mobile station apparatus 2 to the base station apparatus 1 is transmitted using the DFT-spread OFDM scheme, and is configured by an uplink pilot channel UPiCH, a random access channel RACH, an uplink shared channel PUSCH, and an uplink control channel PUCCH. ing.

  In this embodiment, the random access response of asynchronous random access is arranged in a plurality of resource blocks of different time / frequency, and the mobile station device 2 identifies the last random access response from among these random access responses. The base station apparatus 1 notifies whether the random access response to be transmitted is the last or not together with the random access response. That is, the base station apparatus 1 inserts a random access response continuation / end identifier into the random access response and notifies the mobile station apparatus 2 of the random access response, and the mobile station apparatus 2 refers to the random access response continuation / end identifier to perform random access. Whether the response continues or ends can be known before the transmission period of the random access response for the random access transmitted by the own apparatus ends. As a result, the mobile station device 2 that has detected the end of the random access response without detecting the random access response addressed to itself can perform random access again even if the transmission period of the random access response has not ended. it can.

  FIG. 1 is a diagram showing a sequence example of contention random access in which contention occurs between mobile station devices 2 because mobile station device 2 selects a random ID among asynchronous random access using random access channel RACH. is there. First, the mobile station apparatus 2 selects a signature ID from the random ID and downlink path loss or CQI information, and transmits a random access preamble corresponding to the signature ID on the random access channel RACH (Sa1). Here, the random access preamble of the sequence Sa1 is transmitted by a plurality of (for example, nine) mobile station apparatuses 2 with different signature IDs using the random access channel RACH of the resource block in the same time zone. When the base station apparatus 1 receives these nine random access preambles, it generates a synchronization timing shift information by calculating a synchronization timing shift between the mobile station apparatus 2 and the base station apparatus 1 for each received random access preamble. Scheduling for transmitting an L2 / L3 (Layer2 / Layer3) message from the mobile station apparatus 2 is performed to generate scheduling information, and intra-cell mobile station temporary identification information Temporarily C-RNTI, which is temporary intra-cell mobile station identification information Assign.

  Next, the base station apparatus 1 shows that the random access response that is a response addressed to the mobile station apparatus that has transmitted the random access preamble using the random access channel RACH described above is arranged in the downlink shared channel PDSCH. Scheduling information indicating the position of the resource block of the downlink shared channel PDSCH in which the access identification information RA-RNTI and the random access response are inserted, and the random access response size indicating the data size of the random access response are represented by the downlink control channel PDCCH. To place. Further, the base station apparatus 1 adds synchronization timing deviation information, scheduling information, intra-cell mobile station temporary identification to the resource block of the downlink shared channel PDSCH that has notified the arrangement of the random access response by the random access identification information RA-RNTI. Random access response information including the information Temporarily C-RNTI and the received preamble signature ID is arranged and transmitted (Sa2).

  Here, as will be described later, the base station apparatus 1 stores and transmits a maximum of four pieces of random access response information in one random access response. Since the base station apparatus 1 has received nine random access preambles in the sequence Sa1, the sequence Sa2 stores the maximum number of four random access response information and sets the response flag to “0”. A random access response indicating that there is untransmitted random access response information is transmitted. Furthermore, the base station apparatus 1 arranges the random access identification information RA-RNTI, the scheduling information, and the random access response size in the downlink control channel PDCCH as in the sequence Sa2, and 4 of the remaining five random access response information. And a response flag is set to “0” and a random access response indicating that there is untransmitted random access response information is arranged on the downlink shared channel PDSCH and transmitted (Sa3).

  Next, the base station apparatus 1 arranges the random access identification information RA-RNTI, the scheduling information, and the random access response size in the downlink control channel PDCCH as in the sequences Sa2 and Sa3, and stores the remaining one random access response information. And the response flag is set to “1”, and the random access response information indicating the end of the random access response transmission is disposed on the downlink shared channel PDSCH and is transmitted after there is no untransmitted random access response information (Sa4). ). These random access responses of the sequences Sa2 to Sa4 are transmitted within a transmission period Tma2_NB that is a fixed time period from the time of transmission of the random access preamble Sa1.

  The random access identification information RA-RNTI is a specific value that is not used as the intra-cell mobile station identification information, and is a specific value determined by the resource block of the random access channel RACH to which the original random access preamble of the response is transmitted. Value. The mobile station device 2 uses the same value of random access identification information RA-RNTI (sequence Sa2 to Sa4) corresponding to the resource block to which the own device has transmitted the random access preamble, the same as the transmission period Tma2_NB starting from the sequence Sa1. The reception period Tma2_UE that is a period is monitored and detected from the downlink control channel PDCCH. Further, the mobile station device 2 refers to the scheduling information arranged together with the detected random access identification information RA-RNTI, acquires the random access response arranged in the downlink shared channel PDSCH, and from these, Random response information is acquired for the own device whose signature ID matches the signature ID of the random access preamble transmitted by the own device. Note that the transmission period Tma2_NB and the reception period Tma2_UE are the same length.

  Next, the mobile station device 2 is a resource block scheduled based on the scheduling information in the received random response information, and includes at least in-cell mobile station identification information (or in-cell mobile station temporary identification information) L2 / L3 A message is transmitted (Sa5). When the base station apparatus 1 receives the L2 / L3 message from the mobile station apparatus 2, the base station apparatus 1 transmits to the mobile station apparatus 2 a contention resolution for determining whether or not a collision occurs between the mobile station apparatuses 2 ( Sa6)

  The random access identification information RA-RNTI is prepared corresponding to the number of resource blocks that are physical resources of the asynchronous random access channel, and the transmission period Tma2_NB of the random access response for the random access preamble transmitted in the resource block. During this period, the random access identification information RA-RNTI having the same value is not assigned to a plurality of resource blocks. Thereby, if no collision has occurred, the mobile station device 2 is specified by a combination of the value of the random access identification information RA-RNTI and the signature ID of the random access preamble. That is, when there are m asynchronous random access channels on the frequency axis, m random access identification information RA-RNTI exists.

  FIG. 2A is a format example of a random access response arranged in the downlink shared channel PDSCH, and FIG. 2B is information for notifying transmission of a random access response arranged in the downlink control channel PDCCH. This is an example format. The random access response includes a response flag, the number of signatures n, random access response information 1 to random access response information n, and a cyclic redundancy check CRC for these pieces of information. The response flag is a flag indicating whether or not the transmitted random access response is the last random access response whose arrangement is notified by the same random access identification information RA-RNTI as the random access response.

  The signature number n indicates how many pieces of random access response information are included in the random access response. The random access response information includes synchronization timing deviation information, scheduling information, intra-cell mobile station temporary identification information Temporary C-RNTI, and a signature ID (or random ID) of a random access preamble received by the base station apparatus. Here, the maximum number of random access response information arranged in one random access response is four. Note that the number of random access response information that can be included in the random access response may be variable.

  Also, the information notifying the transmission of the random access response arranged in the downlink control channel PDCCH includes random access identification information RA-RNTI, scheduling information, and random access response size. The random access identification information RA-RNTI is a value corresponding to the resource block of the random access channel RACH to which the random access preamble corresponding to the above random access response is transmitted. Scheduling information is information that specifies a resource block in which the above-described random access response is arranged. The random access response size is information indicating the number of bytes of the random access response described above.

  When the base station apparatus 1 receives a random access preamble on a random access channel RACH, the base station apparatus 1 calculates a synchronization timing shift between the mobile station apparatus 2 and the base station apparatus 1 from the preamble, generates synchronization timing shift information, and generates L2 / Scheduling for transmitting an L3 (Layer2 / Layer3) message is performed, scheduling information is generated, and intra-cell mobile station temporary identification information Temporarily C-RNTI is assigned. Then, random access response information including synchronization timing deviation information, scheduling information, intra-cell mobile station temporary identification information Temporary C-RNTI and a corresponding signature ID is created. This operation is performed for the number of detected preambles. After creating random access response information for the number of detected preambles, a random access response storing these random access response information is created.

  Here, when the number of random access response information created as illustrated in FIG. 3A exceeds the maximum number of random access response information that can be stored in one random access response, the base station apparatus 1 Create multiple random access responses. Set the number of random access response information included in the random access response to the number of signatures of each random access response, set “1” to the response flag of the random access response to be transmitted last, Set the response flag to “0”. In the example of FIG. 3A, the number of random access response information is nine, and the maximum number of random access response information that can be stored in one random access response is four. Therefore, in each of the random access responses A1 and A2, the response flag is set to “0”, the number of signatures is set to “4”, and the random access response information is stored four by four. Further, in the random access response A3, the response flag is set to “1”, and the number of signatures is set to “1”. The response flag finally calculates and adds the cyclic redundancy check CRC of each random access response.

  Also, when the number of random access response information created as illustrated in FIG. 3B does not exceed the maximum number of random access response information in one random access response, the base station apparatus 1 has one random access response information. An access response is created, the number of random access response information created is set in the number of signatures of the random access response, and “1” is set in the response flag. In the example of FIG. 3B, the number of random access response information is 3, and the maximum number of random access response information that can be stored in one random access response is 4. Therefore, in the random access response B1, the response flag is set to “1”, the number of signatures is set to “3”, and all random access response information, that is, three are stored. Finally, a cyclic redundancy check CRC of a random access response is added.

  And the base station apparatus 1 calculates the data capacity | capacitance of each random access response, and performs the scheduling which allocates to downlink shared channel PDSCH. Furthermore, the base station apparatus 1 has, on the downlink control channel PDCCH, random access identification information RA-RNTI having a value corresponding to the random access channel RACH to which the random access preamble has been transmitted, scheduling information indicating the position of the random access response, The random access response size is arranged, and the random access response is arranged at the scheduled position and transmitted.

  FIG. 4 is a flowchart for explaining the operation of the random access response reception process of the mobile station apparatus 2. The mobile station apparatus 2 starts a random access response reception process after transmitting the random access preamble. The mobile station apparatus 2 monitors the random access identification information RA-RNTI arranged on the downlink control channel PDCCH (S1). When the mobile station apparatus 2 detects the random access identification information RA-RNTI corresponding to the random access channel RACH that transmitted the random access preamble, the mobile station apparatus 2 detects the position of the random access response from the scheduling information and acquires the random access response.

  First, the mobile station apparatus 2 performs a cyclic redundancy check CRC check of a random access response, and determines whether the random access response is correct data (S2). When it is not correct, the mobile station apparatus 2 returns to step S1 and monitors the random access identification information RA-RNTI again. If it is correct, the process proceeds to step S3, and the mobile station apparatus 2 analyzes the random access response information in the random access response for the number of set signatures. First, the mobile station apparatus 2 determines whether or not the signature ID is the same as the random access preamble transmitted by the mobile station apparatus 2 (S3).

  If the signature ID is the same in this determination, the mobile station apparatus 2 transitions to step S4, and the mobile station apparatus 2 stores the intra-cell mobile station temporary identification information Temporarily C-RNTI in the random access response information of the own mobile station apparatus 2 ( The mobile station apparatus 2 that already has the intra-cell mobile station identification information C-RNTI is discarded). Next, the mobile station apparatus 2 corrects the uplink synchronization timing from the synchronization timing shift information inserted in the random access response information. Furthermore, the mobile station apparatus 2 creates an L2 / L3 message to be transmitted, and transmits an L2 / L3 message created on the uplink shared channel PUSCH assigned by the random access response information scheduling information.

  On the other hand, if the signature ID is not included in the determination in step S3, the process proceeds to step S5, and the mobile station apparatus 2 determines whether the response flag setting of the random access response is “1”. When it is determined that this response flag is “0” and is not set, the mobile station apparatus 2 transitions to step S1 and continues to monitor the random access identification information RA-RNTI, assuming that the random access response continues. Then, the above process is repeated. On the other hand, when it is determined in step S5 that the response flag is “1” and is set, the mobile station apparatus 2 transmits the random access preamble or the random access preamble when the random access response is last. If reception of the access response has failed, the random access response reception process is terminated, and random access preamble transmission is performed again.

  FIG. 5 is a schematic block diagram showing the configuration of the base station apparatus 1. The base station apparatus 1 includes a data control unit 11, an OFDM modulation unit 12, a scheduling unit 13, a channel estimation unit 14, a DFT-S-OFDM demodulation unit 15, a control data extraction unit 16, a preamble detection unit 17, and a radio unit 18. . The scheduling unit 13 includes a DL scheduling unit 21, a UL scheduling unit 20, and a control data creation unit 22. The data control unit (signal arrangement unit) 11 receives user data and control data, and sends control data to the downlink control channel PDCCH, downlink shared channel PDSCH, downlink synchronization channel DSCH, downlink according to an instruction from the scheduling unit 13. The pilot channel DPiCH and the common control channel CCPCH are mapped, and the user data for each mobile station apparatus 2 is mapped to the downlink shared channel PDSCH.

  The OFDM modulation unit 12 performs data modulation on the data mapped to each channel by the data control unit 11, performs serial / parallel conversion of the input signal, IFFT (Inverse Fast Fourier Transform) conversion, CP (Cyclic). Prefix (cyclic prefix) OFDM signal processing such as insertion and filtering is performed to generate an OFDM signal. The radio unit 18 up-converts the OFDM signal generated by the OFDM modulation unit 12 to a radio frequency and transmits the radio signal to the mobile station apparatus 2 via the antenna.

  Further, the radio unit 18 receives an uplink signal from the mobile station apparatus 2 via an antenna, down-converts the baseband signal into a baseband signal, and converts the baseband signal into a DFT-S-OFDM demodulation unit 15, a channel estimation unit. 14 is passed to the preamble detector 17. The channel estimation unit 14 estimates the radio channel characteristics from the uplink pilot channel UPiCH in which a known signal is arranged among the input baseband signals, and the DFT-S-OFDM demodulation unit 15 estimates the radio channel. Pass the result. Further, the channel estimation unit 14 passes the radio channel estimation result to the scheduling unit 13 in order to perform uplink scheduling. The DFT-S-OFDM demodulator 15 demodulates the baseband signal output from the radio unit 18 using the DFT-spread OFDM method to generate received data. At this time, the DFT-S-OFDM demodulation unit 15 uses the propagation path estimation result received from the channel estimation unit 14 and the modulation parameter received from the control data extraction unit 16. The uplink communication scheme is assumed to be a single carrier scheme such as the DFT-spread OFDM scheme or the like, but may be a multicarrier scheme such as the OFDM scheme.

  The control data extraction unit 16 confirms the correctness of the reception data generated by the DFT-S-OFDM demodulation unit 15 and notifies the scheduling unit 13 of the confirmation result. When the received data is correct, the control data extraction unit 16 separates the received data into user data and control data. Further, the control data extraction unit 16 passes the layer 2 control data such as downlink CQI information and downlink data ACK / NACK among the control data to the scheduling unit 13, and controls the other layer 3 control data and the like. User data is output to be passed to higher layers. When the received data is in error, the control data extraction unit 16 stores the received data to be combined with the retransmission data, and performs a combining process when the retransmission data is received.

  The scheduling unit 13 includes a DL scheduling unit 21 that performs downlink scheduling, a UL scheduling unit 20 that performs uplink scheduling, and a control data creation unit 22. The DL scheduling unit 21 is a CQI notified from the mobile station apparatus 2. UL scheduling unit that performs scheduling for mapping user data and control data to each downlink channel from the control data created by the control data creation unit 22 and the data information of each user notified from the information and higher layers 20 is a schedule for mapping user data to each uplink channel from the uplink radio channel estimation result from the channel estimation unit 14 and the resource allocation request from the mobile station apparatus 2 extracted by the control data extraction unit 16. Performing a grayed.

  The control data creation unit 22 creates control data such as ACK / NACK of uplink data, random access preamble allocation, random access response, and synchronization update request. For the random access response, when the preamble detector 17 detects the random access preamble and receives the signature ID corresponding to the preamble, the control data creation unit 22 receives the random access response information for the random access preamble, the response flag ( That is, the random access response of the format shown in FIG. 2 including the random access response information including the random access response information and the random access response information in the transmission period of the random access response information including the random access response information. Information for notifying transmission is generated as control data and output to the data control unit 11. A preamble detection unit (random access detection unit) 17 detects a random access preamble from the baseband signal output from the radio unit 18, calculates a synchronization timing shift amount, and a signature ID corresponding to the detected preamble and a synchronization timing shift amount Are reported to the scheduling unit 13.

  FIG. 6 is a schematic block diagram showing the configuration of the mobile station apparatus 2. The mobile station apparatus 2 includes a data control unit 31, a DFT-S-OFDM modulation unit 32, a scheduling unit 33, an OFDM demodulation unit 34, a channel estimation unit 35, a control data extraction unit 36, a synchronization correction unit 37, a preamble generation unit 38, A signature selection unit 39 and a radio unit 40 are provided. The scheduling unit 33 includes a UL scheduling unit 41, a control data creation unit 42, a control data analysis unit 43, a random access response extraction unit 44, a random access response end detection unit 45, and a retransmission processing unit 46. The data control unit 31 maps the input user data and control data to the uplink shared channel PUSCH according to an instruction from the scheduling unit 33. Further, the data control unit 31 arranges the uplink pilot channel UPiCH. The DFT-S-OFDM modulation unit 32 performs data modulation on the data arranged in each channel by the data control unit 31, and performs DFT-S such as DFT conversion, subcarrier mapping, IFFT conversion, CP (Cyclic Prefix) insertion, and filtering. -Perform OFDM signal processing to generate a DFT-Spread-OFDM signal. The DFT-S-OFDM modulation unit 32 also maps the preamble received from the preamble generation unit 38 to subcarriers, and performs IFFT conversion, CP insertion, and filtering together with other data arranged in each channel by the data control unit 31. And generate a DFT-Spread-OFDM signal. In this embodiment, the uplink communication scheme is assumed to be a single carrier scheme such as DFT-spread OFDM, but may be a multicarrier scheme such as the OFDM scheme.

  The synchronization correction unit 37 corrects the transmission timing based on the synchronization timing shift information passed from the control data extraction unit 36 and passes the DFT-Spread-OFDM signal to the radio unit 40 so as to match the transmission timing. The radio unit 40 up-converts the DFT-Spread-OFDM signal to a radio frequency and transmits it to the base station apparatus 1 via the antenna. Further, the radio unit 40 receives the downlink signal from the base station apparatus 1, down-converts it to a baseband signal, and passes the baseband signal to the OFDM demodulation unit 34 and the channel estimation unit 35. The channel estimation unit 35 estimates the radio channel characteristics from the downlink pilot channel in the baseband signal, and passes the estimation result to the OFDM demodulation unit 34. Also, the channel estimation unit 35 converts the radio channel estimation result into CQI information and notifies the base station device 1 of the radio channel estimation result and passes the CQI information to the scheduling unit.

  The OFDM demodulator 34 demodulates the baseband signal using the radio channel estimation result of the channel estimator 35 to obtain received data. The control data extraction unit 36 separates the received data into user data and control data. The control data extraction unit 36 passes the uplink synchronization timing shift information in the control data to the synchronization correction unit 37, and controls layer 3 control data such as scheduling information and random access response to the scheduling unit 33. Pass data and user data to higher layers. The scheduling unit 33 includes a UL scheduling unit 41, a control data analysis unit 43, a control data creation unit 42, a random access response extraction unit 44, a random access response end detection unit 45, and a retransmission processing unit 46. The UL scheduling unit 41 instructs the data control unit 31 to map data and control information to each uplink channel based on scheduling information passed from the upper layer and control data from the base station apparatus 1.

  Also, the UL scheduling unit 41 instructs the signature selection unit 39 to perform random access when performing random access to the base station device 1. The control data creation unit 42 creates control data such as downlink CQI information, ACK / NACK for downlink data, and L2 / L3 messages for random access procedures. The control data analysis unit 43 analyzes the control data passed from the control data extraction unit 36. The random access response extraction unit 44 converts the random access response information, which is a response of the random access preamble transmitted by the mobile station apparatus 2, from the control data passed from the control data extraction unit 36 to the random access identification information RA-RNTI. And detecting and extracting based on the signature ID. The detection of the random access response information is performed randomly based on the random access identification information RA-RNTI having a value corresponding to the resource block of the random access channel RACH in which the transmitted random access preamble is arranged, and the signature ID of the transmitted random access preamble. This is performed by the access response extraction unit 44. The random access response end detection unit 45 detects the end of transmission of the random access response information during the transmission period of the random access response information in response to the random access preamble transmitted by the mobile station apparatus 2 using the response flag.

  The retransmission processing unit 46 is a random access response end detection unit before the random access response extraction unit 44 detects a response during the transmission period of the random access response information of the response to the random access preamble transmitted by the mobile station apparatus 2. When 45 detects the end of transmission, it instructs the signature selection unit 39 to select a signature ID, thereby instructing retransmission of the random access preamble. The signature selection unit 39 selects a signature ID used in the random access channel according to an instruction from the scheduling unit 33, and passes the selected signature ID to the preamble generation unit 38. When the signature ID is instructed from the scheduling unit 33, the signature selection unit 39 passes the instructed signature ID to the preamble generation unit 38. The preamble generation unit 38 generates a preamble corresponding to the signature ID passed from the signature selection unit 39 and passes it to the DFT-S-OFDM modulation unit 32. In the present embodiment, the signature selection unit 39, the preamble generation unit 38, and the DFT-S-OFDM modulation unit 32 function as a random access transmission unit.

  In this way, the base station device 1 inserts identification information as to whether or not it is the last response into the random access response, and transmits the random access response to the mobile station device 2, so that the mobile station device 2 can access the mobile station device 2 at random access. Since it is possible to determine whether or not the random access response for the random access channel RACH that transmitted the preamble is the last, the mobile station device 2 that has detected the last random access response does not wait for the end of the transmission period Tma2_NB of the random access response, and has an early timing You can execute random access again.

  In the first embodiment described above, the method of inserting the response flag into the random access response arranged in the downlink shared data channel PDSCH has been shown. However, the response flag is inserted into the random access identification information RA as shown in FIG. -You may make it arrange | position to downlink control channel PDCCH with RNTI. Also in this case, as in the case where the response flag is included in the random access response, when the base station apparatus 1 receives the random access preamble, the base station apparatus 1 calculates a synchronization timing shift between the mobile station apparatus and the base station apparatus from the preamble, and performs synchronization timing. Deviation information is generated, the mobile station apparatus 2 performs scheduling for transmitting the L2 / L3 message, generates scheduling information, and allocates intra-cell mobile station temporary identification information Temporary C-RNTI.

  Then, the base station apparatus 1 creates random access response information including synchronization timing deviation information, scheduling information, intra-cell mobile station temporary identification information Temporarily C-RNTI, and a corresponding signature ID. The base station apparatus 1 performs this operation for the number of preambles detected in the same random access channel RACH. After creating random access information for the number of detected preambles, the base station apparatus 1 creates a random access response. Here, when the maximum number of random access response information in one random access response is exceeded, a plurality of random access responses are created. The number of signatures for each random access response is set, and random access response information is stored. The base station apparatus 1 finally adds a cyclic redundancy check CRC for each random access response. Here, unlike the first embodiment, no response flag is stored in the random access response.

  Then, the base station apparatus 1 calculates the data capacity of each random access response, performs scheduling to allocate to the downlink shared channel PDSCH, and sets the positions of the random access identification information RA-RNTI and the random access response to the downlink control channel PDCCH. The scheduling information and the random access response size shown are arranged, and the response flag is set to 1 for the last random access response to be transmitted, and the response flag is set to 0 for other random access responses. Then, a random access response is arranged at the scheduled position and transmitted.

  Next, the mobile station apparatus 2 performs a random access response reception process according to the flowchart shown in FIG. After transmitting the random access preamble, the mobile station device 2 uses the random access identification information RA-RNTI arranged in the downlink control channel PDCCH during the reception period Tma2_UE (= transmission period Tma2_NB), the random access preamble It is monitored whether it matches the random access identification information RA-RNTI corresponding to the access channel RACH (S11). When detecting the corresponding random access identification information RA-RNTI, the mobile station apparatus 2 acquires the position of the random access response from the scheduling information arranged together with the random access identification information RA-RNTI, and analyzes the random access response. . First, the mobile station apparatus 2 performs a cyclic redundancy check CRC check of a random access response, and determines whether the random access response is correct data based on whether this cyclic redundancy check CRC is successful (S12).

  If the cyclic redundancy check CRC fails in step S12 and it is determined that the random access response data is not correct, the mobile station apparatus 2 determines whether the response flag arranged together with the random access identification information RA-RNTI is 1. It is determined whether or not (S15). If it is determined in step S15 that the response flag is 0 and not 1, the mobile station apparatus 2 returns to step S11 assuming that the random access response continues, and again returns the corresponding random access identification information RA-RNTI. Monitor. Also, when it is determined in step S15 that the response flag is 1, the mobile station device 2 ends the random access response reception process, assuming that the random access response is the last and the transmission of the random access preamble has failed. Then, random access preamble transmission is performed again.

  In addition, when the cyclic redundancy check CRC is successful in step S12 and the random access response data is determined to be correct, the mobile station device 2 sets the random access response information in the random access response for the number of signatures set. To analyze. First, the mobile station device 2 determines whether any of the random access response information includes the same signature ID as the preamble transmitted by the mobile station device 2 (S13).

When it is determined that the same signature ID is included, the mobile station apparatus 2 uses the random access response information including the signature ID as the random access response information of the mobile station apparatus (S14). The mobile station apparatus 2 stores the intra-cell mobile station temporary identification information Temporarily C-RNTI among the random access response information (the mobile station apparatus that already has the C-RNTI is discarded), and synchronization timing shift information. Is used to correct the uplink synchronization timing. Furthermore, the mobile station apparatus 2 creates an L2 / L3 message to be transmitted, and transmits an L2 / L3 message created on the PUSCH assigned by the scheduling information included in the random access response information.
If it is determined in step S13 that the same signature ID is not included, the mobile station apparatus 2 transitions to step S15 to determine whether or not the response flag is 1, as described above. The operation is the same as that described after step S15.

As described above, when the random access response flag is arranged in the downlink control channel PDCCH, the mobile station apparatus that failed to demodulate the random access response arranged in the downlink shared data channel PDSCH recognizes whether the random access response is the last one. be able to.
In the first embodiment, the case of contention random access has been described. However, it may be used for non-contention random access, or may be used when contention random access and non-contention random access are mixed. .

[Second Embodiment]
In the first embodiment, the mobile station device 2 determines whether or not the received random access response is the last random access response by inserting a response flag into the random access response and referring to the response flag. The wireless communication system in the second embodiment includes a base station device 3 and a mobile station device 4, and the base station device 3 inserts the remaining random access response information number including the random response without using a response flag. By referring to the number of random access response information, the mobile station apparatus determines whether it is the last random access response.

  Details of the second embodiment will be described below with reference to the drawings. FIG. 9A shows an example of a format of a random access response arranged on the downlink shared channel PDSCH by the base station apparatus 3, and FIG. 9B shows a random access response arranged on the downlink control channel PDCCH. It is an example of the format of the information which notifies transmission of. As shown in FIG. 9, the random access response in the present embodiment includes the remaining response signature number m, random access information 1 to random access information n, and cyclic redundancy check CRC. The random access response remaining number m indicates the number of random access response information transmitted after the random access response including the random access response. The random access response information includes synchronization timing deviation information, scheduling information, intra-cell mobile station temporary identification information Temporary C-RNTI, and a signature ID (or random ID) of a random access preamble received by the base station apparatus 3. Here, the maximum number of random access response information arranged in one random access response is four. The random access response information that can be included in the random access response may be variable.

  Also, the information notifying the transmission of the random access response arranged in the downlink control channel PDCCH includes random access identification information RA-RNTI, scheduling information, and random access response size. The random access identification information RA-RNTI is a value corresponding to the resource block of the random access channel RACH to which the random access preamble corresponding to the above random access response is transmitted. Scheduling information is information that specifies a resource block in which the above-described random access response is arranged. The random access response size is information indicating the number of bytes of the random access response described above.

  FIG. 10 is a diagram illustrating a sequence example of contention random access according to the present embodiment. First, the mobile station apparatus 4 arranges and transmits the random access preamble of the signature ID selected by the own apparatus on the random access channel RACH (Sb1). When the base station apparatus 3 receives the random access preamble, the base station apparatus 3 calculates a synchronization timing shift between the mobile station apparatus 4 and the base station apparatus 3 from the preamble, generates synchronization timing shift information, and generates an L2 / L3 (Layer2 / Layer3) message. Scheduling information is generated, and intra-cell mobile station temporary identification information Temporarily C-RNTI is assigned.

  Then, the base station apparatus 3 creates random access response information including synchronization timing deviation information, scheduling information, intra-cell mobile station temporary identification information Temporarily C-RNTI, and a corresponding signature ID. The base station apparatus 3 performs this operation for the number of preambles that have been detected. The base station apparatus 3 creates random access responses after creating random access information for the number of detected preambles. Here, when the maximum number of random access response information in one random access response is exceeded, a plurality of random access responses are created.

First, the base station apparatus 3 sets the number of remaining response signatures in the random access response. M = m _t − (k−1) × n is set as the response remaining signature number m of each random access response. However, m _t is the total random access response information number, n is one random access response information number that can be transmitted in the random access response, k indicates either sent to the ordinal number random access response is to be set. Finally, a cyclic redundancy check CRC of a random access response is added.

  Then, the data capacity of each random access response is calculated, scheduling to be allocated to the downlink shared channel PDSCH is performed, the scheduling information indicating the position of the random access identification information RA-RNTI and the random access response to the downlink control channel PDCCH, random An access response size is arranged, and a random access response is arranged at a scheduled position and transmitted. Thereby, as shown in FIG. 11A, when the random access response information is nine and the maximum number of random access response information that can be stored in one random access response is 4, the base station apparatus 3 A total of three random access responses with a remaining response signature number of 9, 5, and 1 are generated and transmitted (Sb2, Sb3, Sb4). As shown in FIG. 11B, when the maximum number of random access response information that can be stored in one random access response is four and the random access response information is less than the maximum number, for example, three, the base station apparatus 3 generates and transmits only one random access response having a response remaining signature number of 3.

  After transmitting the random access preamble, the mobile station device 4 operates according to the flowchart shown in FIG. 12 and performs a random access response process. The mobile station apparatus 4 monitors the random access identification information RA-RNTI arranged on the downlink control channel PDCCH (S21). When the mobile station apparatus 4 detects the random access identification information RA-RNTI corresponding to the random access channel RACH in which the random access preamble is arranged, the mobile station apparatus 4 detects the position of the random access response from the scheduling information and analyzes the random access response. To do. First, the mobile station apparatus 4 performs a cyclic redundancy check CRC check of a random access response (S22), and determines whether or not the data is correct. If the cyclic redundancy check fails and it is determined that the data is not correct, the process returns to step S21 and the random access preamble is monitored.

  When it is determined in step S22 that the data is correct, the process proceeds to step S23, and the mobile station apparatus 4 calculates the number k of random access response information arranged in the random access response as follows ( S23). The number of remaining response signatures read from the random access response is m, the number of random access response information that can be transmitted by one random access response is n, and when m−n ≧ 0, the number k of random access response information is n, and m When −n <0, the random access response information number k is m. Next, the mobile station apparatus 4 analyzes the random access response information of the random access response information number k in the random access response.

  In this analysis, the mobile station apparatus 4 determines whether any of the random access response information has the same signature ID as the signature ID of the random access preamble transmitted by the mobile station apparatus (S24). If it is determined in step S24 that there is a signature ID, the mobile station apparatus 4 uses the random access response information including the signature ID as the random access response information of the mobile station apparatus, and performs the following random access response processing. Perform (S26). First, the mobile station apparatus 4 stores the intra-cell mobile station temporary identification information Temporary C-RNTI stored in the random access response information (the mobile station apparatus that already has the C-RNTI is discarded). From the synchronization timing deviation information stored in the random access response information, the uplink synchronization timing is corrected, an L2 / L3 message to be transmitted is created, and assigned by the scheduling information stored in the random access response information The L2 / L3 message created by the generated PUSCH is transmitted.

  When it is determined in step S24 that the same signature ID does not exist, the mobile station apparatus 4 further determines whether m−k> 0 holds, that is, from the number of random access response information stored in the random access response. It is determined whether the number of remaining response signatures is smaller (S25). If it is determined that the determination in step S25 holds, the mobile station apparatus 4 returns to step S11 and again monitors the random access identification information RA-RNTI, assuming that the random access response continues. Repeat the process. If m−k ≦ 0 and it is determined that the determination condition of step S25 does not hold, the random access response is the last random access response for the random access channel RACH random access channel in which the random access preamble is arranged. Yes, it is determined that transmission of the random access preamble has failed, the random access response reception process is terminated, and random access preamble transmission is performed again.

  FIG. 13 is a schematic block diagram illustrating the configuration of the base station device 3 in the present embodiment. In the figure, parts (11, 12, 14-21) corresponding to the parts shown in FIG. The base station apparatus 3 includes a data control unit 11, an OFDM modulation unit 12, a scheduling unit 23, a channel estimation unit 14, a DFT-S-OFDM demodulation unit 15, a control data extraction unit 16, a preamble detection unit 17, and a radio unit 18. . The scheduling unit 23 includes a DL scheduling unit 21, a UL scheduling unit 20, and a control data creation unit 24. For the random access response, when the preamble detection unit 17 detects the random access preamble and receives the signature ID corresponding to the preamble, the control data creation unit 24 receives the random access response information for the random access preamble and the remaining response signature. Of the format shown in FIG. 9 including a number (that is, information indicating the number of random access response information arranged in the random access response after the random access response including the random access response in which the random access response information is arranged). Along with the random access response, information for notifying transmission of the random access response is generated as control data and output to the data control unit 11.

  FIG. 14 is a schematic block diagram showing the configuration of the mobile station device 4 in the present embodiment. In the same figure, parts (31, 32, 34 to 44, 46) corresponding to the respective parts in FIG. The mobile station apparatus 4 includes a data control unit 31, a DFT-S-OFDM modulation unit 32, a scheduling unit 47, an OFDM demodulation unit 34, a channel estimation unit 35, a control data extraction unit 36, a synchronization correction unit 37, a preamble generation unit 38, A signature selection unit 39 and a radio unit 40 are provided. The scheduling unit 47 includes a UL scheduling unit 41, a control data creation unit 42, a control data analysis unit 43, a random access response extraction unit 44, a random access response end detection unit 48, and a retransmission processing unit 46. The random access response end detection unit 48 detects the end of transmission of the random access response information during the transmission period of the random access response information of the response to the random access preamble transmitted by the mobile station apparatus 4 based on the number of remaining response signatures.

  In this way, the base station device 3 can determine the last random access response by indicating the number of random access response information remaining in the random access response, and by transmitting this random access response to the mobile station device 4, the mobile station Since the device 4 can determine whether or not the random access response is the last, the mobile station device that failed to transmit the random access preamble can execute the re-random access earlier than the random access response reception period Tma2_UE elapses.

[Third Embodiment]
In the first and second embodiments, contention random access has been described. However, the radio communication system in the third embodiment includes a base station device 5 and a mobile station device 6, and includes contention random access and non-contention random access. Random access responses are mixed.
The details of the third embodiment will be described below with reference to the drawings. FIG. 15A is a format example of a random access response arranged in the downlink shared channel PDSCH, and FIG. 15B is information for notifying transmission of a random access response arranged in the downlink control channel PDCCH. This is an example format. FIG. 16 is a diagram illustrating an example of storage of random access response information of seven contention random accesses and random access response information of six non-contention random accesses in a random access response.

  The random access response includes the response remaining signature number m1 of the random access response information of the contention random access, the response remaining signature number m2 of the random access response information of the non-contention random access, the random access information 1 to the random access information m1 of the contention random access, It includes random access information 1 to random access information m2 of non-contention random access and cyclic redundancy check CRC. The remaining random access response numbers m1 and m2 indicate the number of random access response information after the transmitted random access response.

  The random access response information of the contention random access includes synchronization timing shift information, scheduling information, intra-cell mobile station temporary identification information Temporarily C-RNTI, and the signature ID (or random ID) of the random access preamble received by the base station apparatus 5. . The random access response information for non-contention random access includes synchronization timing shift information and a signature ID (or random ID) of the random access preamble received by the base station apparatus 5. Here, the maximum number of random access response information arranged in one random access response is 4 on the basis of random access response information of contention random access (8 in the case of non-contention random access random access response information). . The data size of the random access response information for non-contention random access is half the data size of the random access information for contention random access.

  Also, the information notifying the transmission of the random access response arranged in the downlink control channel PDCCH includes random access identification information RA-RNTI, scheduling information, and random access response size. The random access identification information RA-RNTI is a value corresponding to the resource block of the random access channel RACH to which the random access preamble corresponding to the above random access response is transmitted. Scheduling information is information that specifies a resource block in which the above-described random access response is arranged. The random access response size is information indicating the number of bytes of the random access response described above.

  When the base station apparatus 5 receives the random access preamble, it calculates a synchronization timing shift between the mobile station apparatus 6 and the base station apparatus 5 from the preamble and generates synchronization timing shift information. , Perform scheduling for transmitting the L2 / L3 message, generate scheduling information, and allocate intra-cell mobile station temporary identification information Temporary C-RNTI. Then, random access response information including synchronization timing deviation information, scheduling information, intra-cell mobile station temporary identification information Temporary C-RNTI and a corresponding signature ID is created. If it is a signature ID of non-competing random access, synchronization timing deviation information and random access response information including the corresponding signature ID are created. This operation is performed for the number of detected preambles. After creating random access information for the number of detected preambles, a random access response is created. Here, when the maximum number of random access response information in one random access response is exceeded, a plurality of random access responses are created.

  FIG. 15 is a diagram for explaining random access responses when six pieces of random access response information for contention random access and six pieces of random access response information for non-contention random access are created. First, the base station apparatus 5 sets the remaining response signature numbers m1 and m2. Mc− (k1-1) × nc is set as the remaining response number m1 of contention random access for each random access response. However, when m1 is 0 or less, 0 is set. In addition, mc is the number of random access response information of contention random access (here, “6”), and nc is the number of random access response information of contention random access that can be transmitted with one random access response (here, “4”). ), K1 indicates the order in which the random access response to be set is transmitted.

  The remaining response number m2 of non-contention random access for each random access response is set to mn until the remaining response number m1 of contention random access becomes zero. Thereafter, (mn−q) − (k1− (k2 + 1)) × nn is set. However, mn is the number of random access response information for non-contention random access (here, “6”), and nn is the number of random access response information for non-contention random access that can be transmitted with one random access response (here “8”). "), K2 indicates the order of responses (here" 2 ") in which the random access response information of the contention random access is inserted last. q is the number of non-contention random access random access response information (here, “2”) inserted in the k2th response. Finally, a cyclic redundancy check CRC of a random access response is added.

  Then, the data capacity of each random access response is calculated, scheduling to be allocated to the downlink shared channel PDSCH is performed, the scheduling information indicating the position of the random access identification information RA-RNTI and the random access response to the downlink control channel PDCCH, random An access response size is arranged, and a random access response is arranged at a scheduled position and transmitted.

  After transmitting the random access preamble, the mobile station device 6 performs a random access response reception process according to the flowchart shown in FIG. First, the mobile station apparatus 6 monitors the random access identification information RA-RNTI arranged on the downlink control channel PDCCH (S31). When detecting the random access identification information RA-RNTI corresponding to the resource block of the random access channel RACH used when transmitting the random access preamble, the mobile station device 6 is arranged together with the random access identification information RA-RNTI. The position of the random access response is detected from the scheduling information, and the random access response is analyzed.

  First, the mobile station device 6 performs a cyclic redundancy check CRC check of a random access response, and determines whether the random access response is correct data (S32). As a result of this cyclic redundancy check CRC check, if an error is detected and it is determined that the data is not correct, the mobile station device 6 returns to step S31 and monitors the random access identification information RA-RNTI. On the other hand, when the cyclic redundancy check CRC check in step S32 is successful and it is determined that the data is correct, the mobile station device 6 determines the random access response information number s1 of the contention random access arranged in the random access response. The number of random access response information s2 of non-contention random access is calculated as follows (S33).

  When m1−nc ≧ 0, where m1 is the number of random access response information of contention random access that can be stored in the random access response and nc is the number of random access response information s1 of contention random access. The number s2 of random access response information of nc and non-contention random access is 0. Further, assuming that the number of remaining response signatures regarding non-contention random access is m2, and the number of random access response information of non-contention random access that can be stored in the random access response is nn, 0> m1-nc> −4, m2-nn ≧ 0 In this case, the random access response information number s1 for contention random access is m1, and the random access response information number s2 for non-contention random access is (nc−m1) × 2. When m1-nc ≦ −4 and m2-nn ≧ 0, the random access response information number s1 for contention random access is 0, and the random access response information number s2 for non-contention random access is nn. When m1-nc ≦ −4 and m2-nn ≦ 0, the random access response information number s1 for contention random access is 0, and the random access response information number s2 for non-contention random access is m2.

  Next, the mobile station apparatus 6 analyzes the random access response information for the random access response information numbers s1 and s2 in the random access response. The mobile station device 6 determines whether each of the random access response information includes the signature ID transmitted by the mobile station device (S34). When it is determined that the signature ID is included, the mobile station device 6 processes the random access response as follows (S35). In the case of a random access response to the contention random access (when the mobile station apparatus selects a signature), the mobile station apparatus 6 acquires the intra-cell mobile station temporary identification information Temporary C-RNTI from the random access response information and stores it. (The mobile station apparatus that already has C-RNTI is discarded), the uplink synchronization timing is corrected from the synchronization timing deviation information inserted in the random access response information, and the L2 / L3 message to be transmitted is The L2 / L3 message created by the uplink shared channel PUSCH created and assigned by the scheduling information inserted in the random access response information is transmitted. In the case of a random access response to a non-contention random access (when a signature is designated from the base station apparatus), the random access response process determines the uplink synchronization timing from the synchronization timing shift information inserted in the random access response information. Is corrected, and the random access process is terminated.

  On the other hand, when it is determined in step S34 that the signature ID is not included, the mobile station device 6 determines whether m1-s1> 0 or m2-s2> 0 holds (S36). If it is determined that it holds, the random access response continues, so the process returns to step S31, and the mobile station apparatus 6 again monitors the random access identification information RA-RNTI and repeats the above. On the other hand, if it is determined that m1-s1> 0 or m2-s2> 0 is not satisfied and it is not established in step S36, it is determined that the random access response is the last and transmission of the random access preamble has failed. The reception process is terminated, and random access preamble transmission is performed again.

  FIG. 18 is a schematic block diagram showing the configuration of the base station device 5 in the present embodiment. In the figure, parts (11, 12, 14-21) corresponding to the parts shown in FIG. The base station apparatus 5 includes a data control unit 11, an OFDM modulation unit 12, a scheduling unit 25, a channel estimation unit 14, a DFT-S-OFDM demodulation unit 15, a control data extraction unit 16, a preamble detection unit 17, and a radio unit 18. . The scheduling unit 25 includes a DL scheduling unit 21, a UL scheduling unit 20, and a control data creation unit 26. For the random access response, when the preamble detection unit 17 detects the random access preamble and receives the signature ID corresponding to the preamble, the control data creation unit 26 and the random access response information for the random access preamble and the contention random access Response remaining signature number and non-contention random access response remaining signature number (that is, random access of contention random access arranged in a random access response after the random access response including the random access response in which random access response information is arranged) 15 including the number of response information and information indicating the number of random access response information of non-contention random access) With the random access response information for notifying the transmission of the random access response generated as control data, and outputs the data control unit 11.

  FIG. 19 is a schematic block diagram showing the configuration of the mobile station device 6 in the present embodiment. In the same figure, parts (31, 32, 34 to 44, 46) corresponding to the respective parts in FIG. The mobile station device 6 includes a data control unit 31, a DFT-S-OFDM modulation unit 32, a scheduling unit 49, an OFDM demodulation unit 34, a channel estimation unit 35, a control data extraction unit 36, a synchronization correction unit 37, a preamble generation unit 38, A signature selection unit 39 and a radio unit 40 are provided. The scheduling unit 49 includes a UL scheduling unit 41, a control data creation unit 42, a control data analysis unit 43, a random access response extraction unit 44, a random access response end detection unit 50, and a retransmission processing unit 46. The random access response end detection unit 50 determines the end of transmission of the random access response information during the transmission period of the random access response information in response to the random access preamble transmitted by the mobile station apparatus 4 as the remaining response random signature number of the contention random access. Detection is based on the number of remaining response signatures of non-contention random access.

  In this way, even if multiple types of random access are mixed, the base station device 5 can determine the last random access response by indicating the number of random access response information remaining in the random access response, and the mobile station device 6 By transmitting this random access response, the mobile station device 6 can determine whether or not the random access response is the last, so that the mobile station device 6 that failed to transmit the random access preamble can quickly perform re-random access.

  In addition, the data control unit 11, the OFDM modulation unit 12, the scheduling unit 13, the channel estimation unit 14, the DFT-S-OFDM demodulation unit 15, the control data extraction unit 16, the preamble detection unit 17, and the data control in FIG. Unit 31, DFT-S-OFDM modulation unit 32, scheduling unit 33, OFDM demodulation unit 34, channel estimation unit 35, control data extraction unit 36, synchronization correction unit 37, preamble generation unit 38, signature selection unit 39, and FIG. Data control unit 11, OFDM modulation unit 12, scheduling unit 23, channel estimation unit 14, DFT-S-OFDM demodulation unit 15, control data extraction unit 16, preamble detection unit 17, and data control unit 31 in FIG. -S-OFDM modulation unit 32, scheduling unit 47 OFDM demodulation unit 34, channel estimation unit 35, control data extraction unit 36, synchronization correction unit 37, preamble generation unit 38, signature selection unit 39, and data control unit 11, OFDM modulation unit 12, scheduling unit 25, channel in FIG. The estimation unit 14, DFT-S-OFDM demodulation unit 15, control data extraction unit 16, preamble detection unit 17, and data control unit 31, DFT-S-OFDM modulation unit 32, scheduling unit 49, OFDM demodulation unit 34 in FIG. , A program for realizing the functions of the channel estimation unit 35, the control data extraction unit 36, the synchronization correction unit 37, the preamble generation unit 38, and the signature selection unit 39 is recorded on a computer-readable recording medium, and the recording medium is recorded on the recording medium. Load the recorded program into the computer system So, it may perform the processing of each unit by executing. Here, the “computer system” includes an OS and hardware such as peripheral devices.

  The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design and the like within a scope not departing from the gist of the present invention.

  The present invention is suitable for use in a mobile communication system in which a mobile phone terminal device is a mobile station device, but is not limited thereto.

It is the figure which showed the example of a sequence of the contention random access by 1st Embodiment of this invention. It is a format example of the information which notifies transmission of the random access response and random access response in the embodiment. It is a figure which shows the example of storage to the random access response of the random access response information in the embodiment. 6 is a flowchart illustrating an operation of a random access response reception process of the mobile station device 2 in the embodiment. It is a schematic block diagram which shows the structure of the base station apparatus 1 in the embodiment. It is a schematic block diagram which shows the structure of the mobile station apparatus 2 in the embodiment. It is a format example different from FIG. 2 of the information which notifies transmission of the random access response and random access response in the same embodiment. 8 is a flowchart for explaining an operation of a random access response reception process in the format of FIG. 7 of the mobile station apparatus 2 in the embodiment. It is an example of the format of the information which notifies transmission of the random access response and random access response by 2nd Embodiment of this invention. It is a figure which shows the example of a sequence of the contention random access in the same embodiment. It is a figure which shows the example of storage to the random access response of the random access response information in the embodiment. 7 is a flowchart illustrating an operation of a random access response reception process of the mobile station device 4 in the embodiment. It is a schematic block diagram which shows the structure of the base station apparatus 3 in the embodiment. 3 is a schematic block diagram showing a configuration of a mobile station device 4 in the same embodiment. FIG. It is a format example of the information which notifies transmission of the random access response and random access response by 3rd Embodiment of this invention. It is a figure which shows the example of storage to the random access response of the random access response information in the embodiment. 7 is a flowchart illustrating an operation of a random access response reception process of the mobile station device 6 in the embodiment. It is a schematic block diagram which shows the structure of the base station apparatus 5 in the same embodiment. It is a schematic block diagram which shows the structure of the mobile station apparatus 6 in the embodiment. It is a figure which shows the channel structure of the uplink and downlink of the conventional EUTRA. It is the figure which showed the example of the radio | wireless resource structure of the uplink of the conventional EUTRA. It is a sequence diagram which shows the example of a procedure of the contention random access of the conventional asynchronous random access. It is the example of arrangement | positioning to the downlink shared channel PDSCH of the random access response when arrangement | positioning is notified by the random access identification information RA-RNTI of the conventional contention random access. It is a sequence diagram which shows the example of a procedure of the contention free random access of the conventional asynchronous random access. It is the example of arrangement | positioning to the downlink shared channel PDSCH of the random access response when arrangement | positioning is notified by the random access identification information RA-RNTI of the conventional non-contention random access. It is the example of arrangement | positioning to the downlink shared channel PDSCH when the random access response information of the conventional non-contention random access and the random access response information of contention random access are stored in one random access response. It is a figure explaining transmission period Tma2_NB of the conventional base station apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 3, 5 ... Base station apparatus 2, 4, 6 ... Mobile station apparatus 11 ... Data control part 12 ... OFDM modulation part 13, 23, 25 ... Scheduling part 14 ... Channel estimation part 15 ... DFT-S-OFDM demodulation part DESCRIPTION OF SYMBOLS 16 ... Control data extraction part 17 ... Preamble detection part 18 ... Radio | wireless part 20 ... UL scheduling part 21 ... DL scheduling part 22, 24, 26 ... Control data creation part 31 ... Data control part 32 ... DFT-S-OFDM modulation part 33 , 47, 49 ... scheduling unit 34 ... OFDM demodulation unit 35 ... channel estimation unit 36 ... control data extraction unit 37 ... synchronization correction unit 38 ... preamble generation unit 39 ... signature selection unit 40 ... radio unit 41 ... UL scheduling unit 42 ... control Data creation unit 43 ... control data analysis unit 44 ... random access response extraction 45,48,50 ... random access response end detection unit 46 ... retransmission processing unit

Claims (7)

In a wireless communication system comprising a base station device and a plurality of mobile station devices,
The mobile station device
A random access transmitter for transmitting a random access signal to the base station device;
A random access response extraction unit that detects and extracts random access response information that is a response of the random access transmitted by the mobile station device from random access response information in the received signal;
A random access response end detection unit that detects the end of transmission of random access response information during a transmission period of random access response information in response to the random access transmitted by the mobile station device;
During the transmission period of the random access response information of the response to the random access transmitted by the mobile station device, the random access response end detection unit detects the end of transmission before the random access response extraction unit detects the response. A retransmission processing unit that instructs the random access transmission unit to retransmit the random access signal;
The base station device
A random access detector for detecting a random access signal from the received signal;
Control data for generating random access response information for the random access of the detected signal and information capable of determining the end of transmission of a plurality of random access response information during the transmission period of random access response information including the random access response information The creation department;
A radio communication system, comprising: a signal arrangement unit that arranges the generated random access response information and information capable of determining the end of transmission in a transmission signal.   The information capable of determining the end of transmission is a flag indicating whether or not random access response information is arranged in a signal area after the signal area in which random access response information is arranged together with the information during the transmission period. The wireless communication system according to claim 1, wherein:   The information capable of determining the end of transmission is the number of random access response information arranged in the signal area after the signal area including the signal area in which random access response information is arranged together with the information during the transmission period. The wireless communication system according to claim 1, wherein the wireless communication system is information to be expressed.   The random access includes non-contention random access in which the mobile station apparatus transmits a signal according to the determination of the base station apparatus, and contention random access in which the mobile station apparatus transmits a signal determined by the mobile station apparatus. The wireless communication system according to any one of claims 1 to 3, further comprising: A random access transmitter for transmitting a random access signal to the base station device;
A random access response extraction unit that detects and extracts random access response information that is a response of the random access transmitted by the mobile station device from random access response information in the received signal;
A random access response end detection unit that detects the end of transmission of random access response information during a transmission period of random access response information in response to the random access transmitted by the mobile station device;
During the transmission period of the random access response information of the response to the random access transmitted by the mobile station device, the random access response end detection unit detects the end of transmission before the random access response extraction unit detects the response. And a retransmission processing unit that instructs the random access transmission unit to retransmit the random access signal. In a base station device that communicates with a plurality of mobile station devices,
A random access detector for detecting a random access signal from the received signal;
Random access response information that is a response to the detected random access of the signal and information capable of determining the end of transmission of a plurality of random access response information during the transmission period of the random access response information including the random access response information are generated. A control data creation unit,
A base station apparatus comprising: a signal arrangement unit that arranges the generated random access response information and information capable of determining the end of transmission in a transmission signal. In a random access method in a wireless communication system comprising a base station device and a plurality of mobile station devices,
A first process in which the mobile station apparatus transmits a random access signal to the base station apparatus;
A second step in which the base station device detects the random access signal from the received signal received from the mobile station device;
Random access response information for random access of the signal detected in the second process by the base station apparatus, and a plurality of random access response information in a transmission period of random access response information including the random access response information. A third process for generating information capable of determining the end of transmission;
A fourth process in which the base station apparatus arranges and transmits the random access response information generated in the third process and information capable of determining the end of transmission in a transmission signal;
The mobile station apparatus is the random access response transmitted by the mobile station apparatus in the first process from the random access response information in the received signal that has received the transmission signal of the fourth process. A fifth step of detecting and extracting random access response information;
The mobile station apparatus receives information that can determine whether transmission of random access response information is completed during a transmission period of random access response information in response to the random access transmitted by the mobile station apparatus in the first process. And a sixth step of detecting end of transmission of random access response information during the transmission period,
Before the mobile station apparatus detects the response in the fifth process during the transmission period of the random access response information of the response to the random access transmitted by the mobile station apparatus in the first process. And a seventh step of instructing retransmission of the random access signal when transmission end is detected in the sixth step.

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