WO2010087105A1

WO2010087105A1 - Connection processing method and relay station apparatus

Info

Publication number: WO2010087105A1
Application number: PCT/JP2010/000098
Authority: WO
Inventors: 上村克成; 坪井秀和
Original assignee: シャープ株式会社
Priority date: 2009-01-27
Filing date: 2010-01-08
Publication date: 2010-08-05
Also published as: JP2012074757A

Abstract

A mobile station apparatus transmits, to a relay station apparatus, a connection request that requests the connection of the mobile station apparatus to the relay station apparatus and that includes connection request information to be used in a procedure of request for the connection of the mobile station apparatus and a base station apparatus. The relay station apparatus generates and transmits a relay link connection request including the connection request information to the base station apparatus before transmitting, to the mobile station apparatus, a response to the connection request if the connection request includes the connection request information. The base station apparatus determines, based on the connection request information included in the relay link connection request, whether to permit the connection of the mobile station apparatus, and transmits a response including the determination result to the relay station apparatus.

Description

Connection processing method and relay station apparatus

The present invention relates to a connection processing method and a relay station device, and more particularly to a connection processing method via a relay station device.
This application claims priority on Japanese Patent Application No. 2009-015042 filed in Japan on Jan. 27, 2009, the contents of which are incorporated herein by reference.

Evolved Universal Terrestrial Radio Access (hereinafter referred to as EUTRA), which is an evolved version of Advanced AvAd (also known as EUTRAC), which evolved the 3rd generation mobile communication system in 3GPP (3rd Generation Partnership Project) (Referred to as non-patent document 1).

Advanced EUTRA is studying the introduction of relay station devices (also called Relay-Nodes and Relay Stations) that aim to improve data throughput for cell edge users and expand coverage while maintaining compatibility with EUTRA (non-relay) Patent Document 2). The relay station apparatus is a radio relay apparatus (radio relay station) that transmits a signal from the base station apparatus to the mobile station apparatus, or conversely, transmits a signal from the mobile station apparatus to the base station apparatus. Since the relay station apparatus can be used to relay (transfer, relay) signals, it is possible to improve cell edge user performance and expand coverage. In addition, a relay station device can be used as a temporary alternative when dealing with a temporary increase in traffic or when the base station device stops.

In Non-Patent Document 3, the relay station devices are classified into the following types. (1) Layer 1 (L1) relay: a relay station device that performs only simple control such as transmission power control on received data, (2) Layer 2 (L2) relay: demodulation / decoding and remodulation of received data Relay station device that performs re-encoding, (3) Layer 3 (L3) relay: Relay that reconstructs received data up to upper layer protocol data (eg, IP (Internet Protocol) packets) and performs scheduling unique to the relay station device Station equipment.

Here, the relay station apparatus that performs L3 relay has a part or all of the radio resource control (Radio Resource Control: RRC) function, has a cell ID and broadcast information unique to the relay station apparatus, and is transmitted from the mobile station apparatus. Can be recognized as a normal base station apparatus. Therefore, the relay station apparatus that performs L3 relay needs to have a control procedure for the mobile station apparatus. For example, a control processing method such as a handover for selecting the best cell, a random access procedure (Non-Patent Document 4) used to correct a shift in uplink synchronization timing of the mobile station device at the time of initial access or reconnection The relay station device needs to be provided.

However, a connection processing method via a relay station device that performs L3 relay (hereinafter abbreviated as a relay station device) has not been studied so far. Furthermore, since the relay station device relays the signal between the mobile station device and the base station device, the relay station device requires processing time for relaying, and the connection processing is completed as compared with the case where no relay station device is used. There was a problem that it took a long time.

The present invention has been made in view of the above circumstances, and a connection processing method and relay capable of realizing efficient connection processing when connection processing via a relay station device occurs in a mobile station device A station apparatus is provided.

(1) In order to achieve the above object, the present invention has taken the following measures. That is, the connection processing method of the present invention controls a mobile station apparatus, a relay station apparatus connected to the mobile station apparatus, the relay station apparatus, and is connected to the mobile station apparatus via the relay station apparatus. A connection processing method in a communication system comprising: a connection request information used for a connection request procedure between the mobile station device and the control device from the mobile station device; A step of transmitting to the relay station device included in a first connection request message requesting connection to the relay station device; and the relay station device includes the connection request information in the first connection request message. The second connection request message including the connection request information is generated before the response to the first connection request message is transmitted to the mobile station apparatus. Transmitting to the control device; and determining whether or not the control device permits connection of the mobile station device based on connection request information included in the second connection request message, and including a determination result And transmitting a response to the relay station device.

(2) In addition, the connection processing method of the present invention is a response to the first connection request message when the relay station device indicates that the determination result permits connection of the mobile station device. And a step of transmitting a connection setting message, which is a response indicating that the connection from the mobile station apparatus to the relay station apparatus is permitted, to the mobile station apparatus.

(3) In addition, the connection processing method of the present invention is a response to the first connection request message when the relay station device indicates that the determination result does not permit connection of the mobile station device. And a step of transmitting a connection request rejection message, which is a response indicating that the connection from the mobile station apparatus to the relay station apparatus is rejected, to the mobile station apparatus.

(4) In the connection processing method of the present invention, the first connection request message including the connection request information uses a radio resource indicated by a random access response corresponding to a random access channel transmitted by the mobile station apparatus. It is characterized by being transmitted.

(5) Further, the connection processing method of the present invention is characterized in that the control device is a base station device.

(6) Moreover, the relay station apparatus of this invention is a mobile station apparatus, the relay station apparatus connected with the said mobile station apparatus, the said mobile station apparatus via the said relay station apparatus while controlling the said relay station apparatus. A control station connected to the relay station apparatus in a communication system comprising: a first connection request message requesting connection from the mobile station apparatus to the relay station apparatus; A second connection including the connection request information before transmitting a response to the first connection request message to the mobile station apparatus when connection request information used in a connection request procedure with the apparatus is included; It has a control part which performs control which produces | generates a request message and transmits to the said control apparatus.

According to the present invention, an efficient connection processing method can be realized in relay station apparatus communication via a relay station apparatus.

It is a figure explaining the structure of the radio | wireless frame utilized in embodiment of this invention. It is a block diagram which shows an example of the base station apparatus in Embodiment 1 of this invention. It is a block diagram which shows an example of the relay station apparatus in Embodiment 1 of this invention. It is a block diagram which shows an example of the mobile station apparatus in Embodiment 1 of this invention. It is the sequence chart shown about the connection processing method in Embodiment 1 of this invention. It is another sequence chart shown about the connection processing method in Embodiment 1 of this invention. It is the sequence chart shown about the connection processing method in Embodiment 2 of this invention. It is another sequence chart shown about the connection processing method in Embodiment 2 of this invention. It is the figure which showed an example of the method of the conventional relay station apparatus communication. It is the figure shown about the positional relationship of the base station apparatus and relay station apparatus in the conventional relay station apparatus communication. It is another figure shown about the positional relationship of the base station apparatus and relay station apparatus in the conventional relay station apparatus communication. It is the sequence chart which showed the random access procedure of the conventional Contention based Random Access.

Before entering into a specific description of each embodiment, an outline of the communication technology used in the present invention will be briefly described.
(1) Relay Station Device Communication FIG. 9 is a diagram illustrating an example of conventional relay station device communication. In addition to communicating with the mobile station device, the base station device also relays the relay station device to communicate with the mobile station devices under the relay station device. Between the base station apparatus and the relay station apparatus, there is a radio interface (relay link) for exchanging state notification and information regarding relay control. If the relay station device is an L3 relay, the relay station device has a unique cell ID and broadcast information. The relay station device relays the signal received from the mobile station device to the base station device. Alternatively, the signal received from the base station apparatus is relayed to the mobile station apparatus. When relaying, it is also possible to perform scheduling in the relay station device (by demodulating / decoding signals and changing the modulation scheme, coding scheme, transmission power, and resource allocation scheme).

FIG. 10 is a diagram showing a positional relationship between the base station device and the relay station device in relay station device communication. Many of the areas (cells) covered by the relay station apparatus are outside the areas (cells) covered by the base station apparatus. That is, the relay station device is arranged for the purpose of contributing to the expansion of the communication area. FIG. 11 is another diagram showing the positional relationship between the base station apparatus and the relay station apparatus in relay station apparatus communication. The area (cell) covered by the relay station device is in the area (cell) covered by the base station device. That is, the relay station apparatus is arranged for the purpose of contributing to improvement of data throughput. The relay station apparatus of FIG. 10 and FIG. 11 has a unique cell ID different from that of a base station apparatus (also referred to as a donor eNB) connected through a relay link. The mobile station device does not need to distinguish between the relay station device and the base station device. However, it is also possible to make the relay station device and the base station device distinguishable by dividing the cell ID into groups or including identification information in the broadcast information.

(2) Physical channel The physical channel used in EUTRA and Advanced EUTRA is a physical broadcast information channel, an uplink data channel, a downlink data channel, a downlink shared control channel, an uplink shared control channel, a random access channel, a synchronization signal, and a downlink reference signal. There is an uplink reference signal. The physical channel may be added or changed in the future in EUTRA and Advanced EUTRA. However, even if it is changed, the description of each embodiment of the present invention is not affected.

The synchronization signal is used by the mobile station device to detect the base station device (or relay station device) at high speed. The synchronization signal is composed of three types of primary synchronization signals and secondary synchronization signals in which 31 types of codes are alternately arranged, and 504 ways of identifying a base station apparatus by a combination of the signals of the primary synchronization signal and the secondary synchronization signal. The cell ID and the frame timing for radio synchronization are shown. The mobile station apparatus specifies the cell ID received by the cell search.

A physical broadcast information channel (PBCH: Physical Broadcast Channel) is transmitted for the purpose of notifying control parameters (broadcast information) that are commonly used by mobile station apparatuses in the cell. Broadcast information that is not notified on the physical broadcast information channel is transmitted using the downlink data channel with the radio resource notified on the downlink shared control channel. Broadcast information includes a cell global ID unique to the system, uplink frequency band information, and the like.

The downlink reference signal is a pilot signal transmitted at a predetermined power for each cell. The downlink reference signal is a signal that is periodically repeated at a predetermined time interval (for example, one frame), and the mobile station apparatus receives the downlink reference signal at a predetermined time interval and measures the reception quality. This is used to judge the reception quality for each cell. Further, it is used as a reference signal for demodulating downlink data transmitted simultaneously with the downlink reference signal. As long as the sequence used for the downlink reference signal is a sequence that can be uniquely identified for each cell, an arbitrary sequence may be used. The downlink reference signal may be described as DL-RS (Downlink Reference signal), but its use and meaning are the same.

The downlink shared control channel (PDCCH: Physical Downlink Common Channel) is transmitted in the first few symbols of each subframe, and resource allocation information according to the scheduling of the base station apparatus (or relay station apparatus) to the mobile station apparatus, Used to indicate the amount of transmission power adjustment. The mobile station apparatus needs to receive the downlink shared control channel before transmitting / receiving traffic data (user data) and control messages, acquire uplink resource allocation during transmission, and acquire downlink resource allocation information during reception.

The downlink data channel (PDSCH: Physical Downlink Shared Channel) is used to transmit a part of paging information and broadcast information in addition to traffic data.

The uplink data channel (PUSCH: Physical Uplink Shared Channel) mainly transmits traffic data, and can include control data such as downlink quality and ACK / NACK.

A random access channel (PRACH: Physical Random Access Channel) is a channel used to transmit a preamble sequence and has a guard time. The random accelerator channel is used as an access procedure to the base station apparatus (or relay station apparatus) when the uplink transmission timing is asynchronous, and is used for adjusting resource requests and uplink transmission timing. Since other physical channels are not related to the embodiments of the present invention, detailed description thereof is omitted.

(3) Random access procedure There are two methods for random access: Contention based Random Access and Non-contention based Random Access. The Contention based Random Access is a random access that may collide between mobile station apparatuses, and is a random access that is normally performed during connection processing. Non-contention based random access is a random access in which no collision occurs between mobile station apparatuses, and is a random access used to quickly establish uplink synchronization between a mobile station apparatus and a base station apparatus. In special cases such as this, it is performed by the base station apparatus.

In Contention based Random Access, a random access preamble (also simply referred to as a preamble) is transmitted through a random access channel in order to establish uplink synchronization (correct the uplink synchronization timing). The preamble includes a signature which is a signal pattern representing information, and several tens of types of signatures can be prepared to express several bits of information. In EUTRA, it is assumed that 6-bit information is transmitted, and it is assumed that 64 types of signatures are prepared. The 6-bit information is determined based on the random ID, 5 bits being the random ID, and the remaining 1 bit being the downlink path loss and the amount of uplink data transmitted after the random access channel.

Here, the outline of the communication procedure of Contention based Random Access and Non-Contention based Random Access will be described.

FIG. 12 is a sequence chart showing a procedure example of Contention based Random Access. Contention based Random Access is used for initial access, reconnection, Inter-RAT handover, and so on.

In step S1, the mobile station apparatus receives broadcast information from the base station apparatus and acquires signature information (such as radio resource information of a random access channel and signature group information) for selecting a signature to be transmitted. When a random access request is generated (step S2), a signature is selected based on the signature information, and the selected preamble is transmitted to the base station apparatus using the random access channel (step S3).

When the base station apparatus receives the random access channel from the mobile station apparatus, the base station apparatus calculates an uplink synchronization timing shift (Timing Advance) between the mobile station apparatus and the base station apparatus from the transmitted preamble, and a random access response (random access response) Mobile station apparatus that performs scheduling to transmit a message, assigns temporary C-RNTI (Cell-Radio Network Temporary Identifier) as a temporary identifier to the mobile station apparatus, and transmits a preamble to the downlink shared control channel (PDCCH) RA-RNTI (Random Access-Radio Temporary 示す Identifer) that is an identifier indicating a response addressed to and a downlink data channel resource allocation information are arranged, and uplink synchronization timing shift information and uplink scheduling information are assigned to the downlink data channel (PDSCH). Place Tempolary C-RNTI and the received preamble signature ID number (or random ID), and transmits the downlink data channel and the downlink shared control channel as a random access response (step S4).

Upon confirming that the downlink shared control channel (PDCCH) has RA-RNTI, the mobile station apparatus confirms the contents of the random access response arranged in the downlink data channel (PDSCH), and transmits the signature ID number ( Alternatively, a response including a random ID) is extracted. Then, the uplink synchronization timing deviation is corrected, and uplink scheduling data including Temporary C-RNTI is transmitted using the scheduled radio resource (step S5). Note that the mobile station apparatus continues to wait for a random access response from the base station apparatus for a certain period, and when it does not receive the random access response including the signature ID number of the transmitted preamble, it transmits the preamble again.

When the base station apparatus receives the uplink scheduling data from the mobile station apparatus, the base station apparatus uses the Temporary C-RNTI included in the received uplink scheduling data to determine whether the mobile station apparatus has a collision between the mobile station apparatuses. Downlink scheduling data to be transmitted to the mobile station apparatus (step S6). The downlink scheduling data is also called contention resolution. The mobile station apparatus determines that the random access has succeeded by correctly receiving the downlink scheduling data within the time limit, and ends the random access procedure. Then, Temporary C-RNTI is not temporary, but is used as an identifier (C-RNTI) for identifying the mobile station apparatus in the cell.

On the other hand, in the non-contented based random access, the base station device selects the signature ID number and notifies the mobile station device. The mobile station apparatus uses the notified signature and transmits a preamble using a random access channel.

When the base station apparatus receives the preamble from the mobile station apparatus, the base station apparatus calculates an uplink synchronization timing shift between the mobile station apparatus and the base station apparatus from the preamble, and transmits the random access channel to the downlink shared control channel (PDCCH). A C-RNTI is arranged to indicate a response addressed to the station apparatus, and a random access response including uplink synchronization timing shift information is transmitted. The mobile station apparatus corrects the uplink synchronization timing shift from the received random access response, and determines that the random access has been correctly completed.

In the following embodiment, a realistic situation of the control method of the relay station apparatus in the OFDM (Orthogonal Frequency Division Multiplexing Access) communication method is specifically assumed, and a condition for performing connection processing with a random access procedure is set. Then, under the condition setting, an optimum connection processing method (random access method) that can reduce the delay amount between the mobile station device, the relay station device, and the base station device is determined. Below, each condition assumed in common with embodiment of this invention is demonstrated.

(Condition 1) The relay station device has an L3 relay function. That is, the relay station apparatus and the base station apparatus having a part or all of RRC functions (condition 2) are in radio frame synchronization (condition 3). The mobile station apparatus needs to discriminate between the relay station apparatus and the base station apparatus. There is no. That is, there is no need for a connection processing method different from EUTRA for the relay station apparatus (condition 4). The radio frame structure of EUTRA is not changed.

More strictly, for condition 1, the relay station device transmits a cell ID or broadcast information different from that of the base station device (donor eNB), and the preamble transmission and the random access response in the random access procedure are relay station devices. The relay station device performed between the mobile station device and the mobile station device is included in Condition 1. That is, the relay station apparatus that meets the condition 1 does not relay the received preamble or random access response to the base station apparatus or the mobile station apparatus.

Regarding condition 2, it is assumed that the relay station device and the base station device exchange information with each other through the relay link before the mobile station device starts the random access procedure. By exchanging this information, the relay station apparatus and the base station apparatus fully grasp the positional relationship and propagation path information, and radio frame synchronization is established with each other. The radio frame synchronization means that the deviation of the OFDM symbol reception timing is within the guard time at the receiving antenna ends of the relay station apparatus and the base station apparatus. This means that the mobile station device does not need to correct the uplink synchronization timing with the base station device by the random access procedure. That is, the relay station device does not need to relay the preamble transmitted from the mobile station device to the base station device.

Regarding Condition 3, Condition 3 is a condition (transparent communication) necessary for the EUTRA mobile station apparatus to communicate via the relay station apparatus. When the mobile station apparatus uses the same connection processing method as EUTRA, backward compatibility (Backward Compatibility) can be provided, and it is not necessary to request an additional function from the mobile station apparatus. According to Condition 3, the mobile station apparatus performs the same random access procedure when the base station apparatus or the relay station apparatus transmits the random access channel when the connection process is started.

Regarding Condition 4, an example of the structure of a downlink radio frame satisfying Condition 4 will be described with reference to FIG. FIG. 1 shows a radio frame structure common to the relay station apparatus and the base station apparatus. As the communication method, the OFDM communication method is preferable. The radio frame is composed of a resource block bandwidth composed of a plurality of subcarriers (for example, 12 subcarriers) and a two-dimensional resource block (Resource Block) with a subframe of a fixed time (for example, 1 millisecond).

1 frame consists of 10 subframes. Also, the first OFDM symbol time of the resource block is used as a downlink shared control channel, and the remaining OFDM symbols are used by a downlink data channel, a multicast channel, or relay station control data. The mobile station device does not need to receive relay station control data. A multicast channel (PMCH: Physical Multicast Channel) is a channel for transmitting broadcast data to a plurality of non-specific mobile station apparatuses. The base station apparatus or relay station apparatus reserves in advance a subframe in which a multicast channel or relay station control data is transmitted.

The base station apparatus and the relay station measure may set different identification information for distinguishing the multicast channel or the relay station control data, and notify the identification information to the mobile station apparatus by broadcast information.
In consideration of the above matters, embodiments of the present invention will be specifically described below.

(Embodiment 1)
Embodiment 1 of the present invention will be described below.
FIG. 2 is a block diagram showing an outline of base station apparatus 100 according to Embodiment 1 of the present invention. The base station apparatus 100 includes a reception unit 101, a demodulation unit 102, a decoding unit 103, a random access processing unit 104, an upper layer 105, a control unit 106, a coding unit 107, a reference signal generation unit 108, a modulation unit 109, a multiplexing unit 110, The transmitter 111 includes a receiving antenna AN11 and a transmitting antenna AN12. In FIG. 2, other components of base station apparatus 100 are omitted because they are not related to the present embodiment.

The upper layer 105 inputs relay station control data for relay station control to the encoding unit 107. In addition, traffic data and a control signal for the mobile station apparatus are input to the encoding unit 107. For mobile station devices, communication via relay station devices is also included. The encoding unit 107 encodes the input data and inputs it to the modulation unit 109. Modulator 109 modulates the encoded signal. Further, the signal output from the modulation unit 109 and the downlink reference signal generated by the reference signal generation unit 108 are mapped to the frequency domain by the multiplexing unit 110. An output signal from the multiplexing unit 110 is input to the transmission unit 111. The transmitter 111 converts a frequency domain signal into a time domain signal, and amplifies the power by placing it on a carrier wave having a predetermined frequency. The signal output from the transmission unit 111 is transmitted from the transmission antenna AN12.

Further, a signal received by the receiving antenna AN11 is input to the receiving unit 101. The receiving unit 101 converts a signal received from a mobile station device or a relay station device into a baseband digital signal, and the converted signal is input to the demodulation unit 102 and demodulated. The signal demodulated by the demodulator 102 is then input to the decoder 103 and decoded, and the control data and traffic data decoded correctly are output to the upper layer 105. When the received signal is uplink scheduling data corresponding to a random access response transmitted from a random access channel transmitted from the mobile station apparatus or an uplink shared control channel, the decoding unit 103 outputs the random access data to the random access processing unit 104 To do.

The random access processing unit 104 determines whether or not the random access procedure is correctly performed, and outputs the result to the upper layer 105. The upper layer 105 determines whether or not the random access procedure is continued based on the result of the random access processing unit 104. Similarly, relay station control data transmitted from the relay station device is output to the upper layer 105. Control information necessary for control of each block is input from the upper layer 105 to the control unit 106, and control information related to transmission from the control unit 106 is transmitted as transmission control information by the encoding unit 107, the reference signal generation unit 108, the modulation Control information related to reception is appropriately input to each block of the reception unit 101, demodulation unit 102, and decoding unit 103 as reception control information in each block of the unit 109, multiplexing unit 110, and transmission unit 111.

FIG. 3 is a block diagram showing an outline of the relay station apparatus 200 according to Embodiment 1 of the present invention. The relay station apparatus 200 includes a receiving unit 201, a demodulating unit 202, a decoding unit 203, a random access processing unit 204, an upper layer 205, a control unit 206, a coding unit 207, a reference signal generation unit 208, a modulation unit 209, a multiplexing unit 210, A transmission unit 211, a control information selection unit 212, a reception antenna AN21, and a transmission antenna AN22 are included. In FIG. 3, other components of the relay station apparatus 200 are omitted because they are not related to the present embodiment.

The upper layer 205 inputs relay station control data for relay station control to be transmitted to the base station apparatus to the encoding unit 207. Further, the traffic data and the control signal are input to the encoding unit 207. If the traffic data and the control signal are for the base station device, the data received from the mobile station device received by the receiving unit 201 is transmitted via the upper layer 205. On the other hand, for a mobile station device, data received from the base station device by the receiving unit 201 is transmitted via the upper layer 205. The encoding unit 207 encodes the input data and inputs it to the modulation unit 209. Modulation section 209 modulates the encoded signal. Further, the signal output from the modulation unit 209 and the reference signal generated by the reference signal generation unit 208 are mapped to the frequency domain by the multiplexing unit 210.

The reference signal is mapped to a downlink reference signal for a mobile station apparatus, and to an uplink reference signal for a base station apparatus. An output signal from the multiplexing unit 210 is input to the transmission unit 211. The transmission unit 211 converts a frequency domain signal into a time domain signal, and performs power amplification on a carrier wave having a predetermined frequency. The signal output from the transmission unit 211 is transmitted from the transmission antenna AN22.

Further, a signal received by the receiving antenna AN21 is input to the receiving unit 201. The receiving unit 201 converts a signal received from the mobile station device or the base station device into a baseband digital signal, and the converted signal is input to the demodulating unit 202 and demodulated. The signal demodulated by the demodulator 202 is then input to the decoder 203 and decoded, and the control data and traffic data decoded correctly are output to the upper layer 205. When the received signal is uplink scheduling data corresponding to a random access response transmitted from a random access channel transmitted from the mobile station apparatus or an uplink shared control channel, the decoding unit 203 outputs the random access data to the random access processing unit 204 To do.

The random access processing unit 204 determines whether or not the random access procedure is correctly executed, and outputs the result to the upper layer 205. The upper layer 205 determines whether or not the random access procedure is continued based on the result of the random access processing unit 204. The relay station control data transmitted from the base station apparatus is output to the upper layer 205. Control information necessary for control of each block is selected by the control information selection unit 212 and input to the control unit 206 prior to transmission / reception with each station. When transmitting / receiving the relay station control data, the relay station control information is input to the control unit 206. When transmitting / receiving control data and traffic data to / from the base station apparatus, base station apparatus control information is input to the control unit 206.

In addition, when transmitting / receiving control data and traffic data to / from the mobile station apparatus, mobile station apparatus control information is input to the control unit 206. With respect to each control information described above, control information related to transmission is transmitted control information as control information related to reception in each block of the encoding unit 207, the reference signal generation unit 208, the modulation unit 209, the multiplexing unit 210, and the transmission unit 211. Information is appropriately input to each block of the receiving unit 201, the demodulating unit 202, and the decoding unit 203 as reception control information.

FIG. 4 is a block diagram showing an example of mobile station apparatus 300 according to Embodiment 1 of the present invention. The mobile station apparatus 300 includes a reception unit 301, a demodulation unit 302, a decoding unit 303, an upper layer 304, a control unit 305, a random access generation unit 306, a coding unit 307, a modulation unit 308, a transmission unit 309, a reception antenna AN31, and a transmission antenna. It is composed of AN32. Prior to reception, control information is input from the upper layer 304 to the control unit 305, and control information related to reception is appropriately input as reception control information to the reception unit 301, demodulation unit 302, and decoding unit 303. The reception control information includes information such as reception timing, multiplexing method, and resource arrangement information regarding each channel in addition to information on the reception frequency band. In FIG. 4, other components of mobile station apparatus 300 are omitted because they are not related to the present embodiment.

The signal received by the receiving antenna AN31 (transmitted signal from the base station device or relay station device) is received by the receiving unit 301. The received signal is input to the demodulator 302. Demodulation section 302 demodulates the input received signal, inputs a signal to decoding section 303 to correctly decode downlink traffic data and downlink control data, and inputs each decoded data to higher layer 304 To do.

Prior to transmission, control information is input from the upper layer 304 to the control unit 305, and control information related to transmission is appropriately transmitted to the random access generation unit 306, encoding unit 307, modulation unit 308, and transmission unit 309 as transmission control information. Entered. The transmission control information includes information such as code information, modulation information, transmission timing for each channel, multiplexing method, and resource allocation information as uplink scheduling information of the transmission signal. The random access information is input to the random access generation unit 306, and random access data is generated. The random access information includes preamble information and radio resource information.

The upper layer 304 inputs random access information to the random access generation unit 306 at the time of initial access or reconnection. In addition to the random access data, uplink traffic data and uplink control data are input to the encoding unit 307 from the upper layer 304. The encoding unit 307 appropriately encodes each data according to the transmission control information and outputs the data to the modulation unit 308. The modulation unit 308 modulates the output from the coding unit 307. The transmission unit 309 maps the output of the modulation unit 308 to the frequency domain, converts the frequency domain signal into a time domain signal, and performs power amplification on a carrier wave of a predetermined frequency. The signal output from the transmission unit 309 is transmitted from the transmission antenna AN32.

FIG. 5 is a sequence chart showing an example of the connection processing method in Embodiment 1 of the present invention, and uses Contention based Random Access. The mobile station device is located in a range where communication with the relay station device is possible, and transmits a random access channel to the relay station device. The positional relationship between the relay station device and the base station device may be either the positional relationship shown in FIG. 10 or FIG. Prior to the start of the random access procedure of the mobile station device, the relay station device and the base station device have established a wireless connection (relay link) in advance and are synchronized with each other in radio frame.

The mobile station apparatus according to the present embodiment performs uplink synchronization with the relay station apparatus, not the base station apparatus. Also, the relay station device does not transmit the random access channel transmitted by the mobile station device to the base station device via the relay link, and further does not transmit uplink scheduling data (connection request message) to the base station device via the relay link. It is characterized by. The uplink scheduling data transmitted by the mobile station device is a control message for requesting a connection (reconnection) procedure, and processing with low delay is required. The relay station apparatus completes connection (reconnection) processing in the relay station apparatus in order to prevent a delay from occurring by transmitting the uplink scheduling data to the base station apparatus.

The mobile station device is located in an area (cell) covered by the relay station device, identifies a synchronization signal of the relay station device using a cell search procedure, and is in a standby (camping) state. At this time, the mobile station apparatus receives broadcast information from the relay station apparatus in step S10, and acquires signature information (such as radio resource information of a random access channel and signature group information) for selecting a signature to be transmitted.

Then, when a random access request is generated for reasons such as initial access, reconnection, or Inter-RAT handover (step S11), the signature is selected based on the signature information, and the selected preamble is selected using the random access channel. Is transmitted to the relay station device (step S12).

When the relay station apparatus receives the random access channel transmitted from the mobile station apparatus, the relay station apparatus calculates an uplink synchronization timing shift between the mobile station apparatus and the relay station apparatus from the transmitted preamble, and generates a random access response (random access response). RA which is an identifier indicating a response addressed to a mobile station apparatus which has performed scheduling for transmission, assigned a temporary identifier C-RNTI as a temporary identifier to the mobile station apparatus, and transmitted a preamble to the downlink shared control channel (PDCCH) -Resource allocation information of RNTI and downlink data channel is arranged, and uplink synchronization timing shift information, uplink scheduling information, Temporary C-RNTI and signature ID number of received preamble (or the downlink data channel (PDSCH)) Place the random ID), and transmits the downlink data channel and the downlink shared control channel as a random access response (step S13).

Upon confirming that the downlink shared control channel (PDCCH) has RA-RNTI, the mobile station apparatus confirms the contents of the random access response arranged in the downlink data channel (PDSCH), and transmits the signature ID number ( Alternatively, a response including a random ID) is extracted. Then, the uplink synchronization timing deviation is corrected, and connection request information including Temporary C-RNTI is arranged and transmitted in the connection request message with the scheduled radio resource (step S14). Note that the mobile station device continues to wait for a random access response from the relay station device for a certain period, and when it does not receive a random access response including the signature ID number of the transmitted preamble, returns to step S12 and transmits the preamble again. .

The relay station device that has received the connection request message checks the connection request information included in the connection request message, and determines whether or not to permit the connection. And when permitting a connection, a connection setting message is transmitted to a mobile station apparatus (step S15). The relay station apparatus arranges connection setting information (radio resource configuration: Radio Resource Configuration) used by the mobile station apparatus in the connection setting message.

The mobile station apparatus that has received the connection setting message applies the radio resource setting indicated by the connection setting information, and transmits a connection setting completion message including the connection setting completion information to the relay station apparatus (step S16). Thereafter, Temporary C-RNTI is used as a normal C-RNTI.

That is, the relay station apparatus according to the present embodiment has a function of receiving a random access channel transmitted from a mobile station apparatus, a function of calculating an uplink synchronization timing shift from a preamble included in the received random access channel, and a downlink shared RA-RNTI and downlink data channel resource allocation information are arranged on the control channel (PDCCH), and uplink synchronization timing shift information, uplink scheduling information, Temporary C-RNTI, and signature ID number of the received preamble are assigned to the downlink data channel (PDSCH). (Or random ID) is arranged and transmitted as a random access response.

Also, it has a function of receiving a connection request message (uplink scheduling data) based on uplink scheduling information instructed by a random access response, checking connection request information of the received connection request message, and determining whether or not to permit connection. When connection is permitted, connection setting information (radio resource setting) and the like are arranged in the connection setting message and transmitted to the mobile station apparatus. In addition, it has a function of receiving a connection setting completion message that is a response message to the connection setting message.

The relay station apparatus that has received the connection setting completion message transmits a relay link connection request message using the relay link to the base station apparatus (donor eNB) (step S17). The relay link connection request message is transmitted using radio resources allocated in advance from the base station apparatus to the relay station apparatus. The relay link connection request message is transmitted to the base station device when the random access procedure is completed between the mobile station device and the relay station device, and is not transmitted at other timings.

The relay station device includes at least the following relay link connection request information in the relay link connection request message. (1) C-RNTI (or Temporary C-RNTI) of connected mobile station device, (2) Connection request information notified by connection request message, (3) Connection setting completion information notified by connection setting completion message . The connection request information notified in (2) is, for example, a connection request reason. The connection setting completion information notified in (3) is, for example, a selected PLMN (Public Land Mobile Network) -ID. It should be noted that the control of the relay station device can be simplified by including the connection request message and the connection setting completion message as they are in the relay link connection request message.

The base station apparatus that has received the relay link connection request message determines that the radio link connection has been completed between the mobile station apparatus and the relay station apparatus notified by the relay link connection request message. Then, whether the mobile station apparatus can participate in the network is determined from the load status of the base station apparatus, and if it is determined that participation is possible, a relay link connection completion message is transmitted to the relay station apparatus (step S18).

The relay link connection completion message may be transmitted using a radio resource allocated in advance from the base station device to the relay station device, or a relay station device identifier (relay station device ID, Relay-RNTI), the relay station apparatus monitors the downlink shared control channel (PDCCH), and the radio resource indicated by the downlink shared control channel in which the relay station apparatus identifier is arranged (downlink scrambled with at least the relay station apparatus identifier) (Data channel).

The base station device generates a control message after the connection setting completion message based on the information notified by the relay link connection request message, and transmits it to the relay station device (step S19). As described above, the control message transmitted in step S19 may be transmitted using radio resources allocated in advance from the base station apparatus to the relay station apparatus, or a relay station apparatus identifier is arranged. In addition, transmission may be performed using radio resources (downlink data channel scrambled with at least a relay station apparatus identifier) indicated by the downlink shared control channel. The control message transmitted in step S19 is, for example, a security setting message or a wireless connection reset message.

The relay station device that has received the control message demodulates and decodes the control message, recovers the data error that occurred between the base station device and the relay station device by error correction, and takes into account the load status and interference between adjacent cells. Scheduling is determined, and the control message is re-encoded and re-modulated based on the scheduling. Then, the error-corrected control message is transmitted to the mobile station apparatus (step S20). The method for transmitting the control message from the relay station apparatus is the same as the normal EUTRA method. That is, the relay station apparatus transmits a control message to the mobile station apparatus using the radio resource indicated by the downlink shared control channel in which C-RNTI is arranged.

Note that step S19 can be omitted by including the information of the control message transmitted in step S20 in FIG. 5 in the relay link connection completion message in step S18.

FIG. 6 is a sequence chart showing another example of the connection processing method according to Embodiment 1 of the present invention, and shows an example in which the relay link connection request is rejected by the base station device after the procedure of Contention based Random Access. Conditions at the start of the random access procedure are the same as in FIG.

Since the relay station device that has received the connection setting completion message of the mobile station device transmits the relay link connection request message using the relay link to the base station device (donor eNB), it is the same as FIG. Is abbreviated.

The base station apparatus that has received the relay link connection request message determines that the random access procedure has been completed between the mobile station apparatus notified by the relay link connection request message and the relay station apparatus. If the mobile station apparatus can participate in the network based on the load status of the base station apparatus and the like, if it is determined that participation is not possible (not permitted), a relay link connection request rejection message is transmitted to the relay station apparatus (Step S21).

The relay link connection request rejection message may be transmitted from the base station apparatus using a radio resource allocated in advance to the relay station apparatus, or a relay station apparatus identifier (relay station apparatus ID) that is different for each relay station apparatus. , Relay-RNTI), the relay station apparatus monitors the downlink shared control channel (PDCCH), and the radio resource indicated by the downlink shared control channel in which the relay station apparatus identifier is arranged (at least scrambled with the relay station apparatus identifier) A relay link connection request rejection message may be transmitted using a downlink data channel.

The relay station device that has received the relay link connection request rejection message determines that the relay link connection request has failed, and sets the connection in the connection setting release message so that the mobile station device releases the established radio resource information. It transmits including release information (step S22). The connection setting release information is, for example, a control stop time (wait time). Then, the information notified from the mobile station apparatus during the connection process and the C-RNTI (or Temporary-RNTI) information allocated to the mobile station apparatus are deleted, and the random access procedure is terminated.

As the control message between the mobile station apparatus and the relay station apparatus shown in FIG. 5 or FIG. 6, a control message (RRC signaling) used in EUTRA can be used. For example, the RRCConnectionRequest or RRCConnectionReestablishmentRequest can be used as the connection request message. The connection setting message can use RRCConnectionSetup or RRCConnectionReestablishment.

Also, RRCConnectionSetupComplete or RRCConnectionReestablishmentComplete can be used for the connection setting completion message. As the security setting message, SecurityModeCommand can be used. The radio connection reconfiguration message can use RRCConnectionReconfiguration. The RRCConnectionRelease can be used for the connection setup release message.

Also, the control message between the base station apparatus and the relay station apparatus shown in FIG. 5 or FIG. 6 is preferably transmitted in a subframe reserved for transmitting relay station control data.

According to this embodiment, the relay station device has a function of processing the same random access procedure as that of the base station device. Further, when the relay station apparatus receives the connection setting completion message, the relay station apparatus transmits a relay link connection request message to the base station apparatus to notify that the mobile station apparatus newly requests to join the network. When the relay link connection request completion message is received, the control message transmitted from the base station device is relayed to the mobile station device.

According to this embodiment, even in a network in which a relay station apparatus is introduced in Advanced EUTRA, the mobile station apparatus can perform the same control as the connection processing method of the conventional EUTRA. For this reason, the mobile station apparatus does not require addition of a new function, and can suppress an increase in the hardware circuit scale or the memory capacity used by the software.

Also, since the relay station device has a function of processing a random access procedure, it is not necessary to relay each piece of information related to random access to the base station device, and the delay time is shortened. Therefore, even when the relay station apparatus is used, the processing time required for the connection process can be minimized.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. In the first embodiment, the relay station device transmits the relay link connection request message to the base station device after receiving the connection setting completion message. However, in order to establish a connection with the base station device after connection setting between the relay station device and the mobile station device is completed, for example, when a relay link connection request is rejected, the processing time up to that time is wasted There was a case.

Therefore, in the second embodiment, an optimal connection of the relay station apparatus considering the case where the connection request is rejected by the base station apparatus by transmitting a relay link connection request message to the base station apparatus before the connection setting is completed. A processing method will be described. The mobile station device, relay station device, and base station device in the present embodiment may be the same as those in the first embodiment.

FIG. 7 is a sequence chart showing an example of the connection processing method according to the second embodiment of the present invention, and uses Contention based Random Access. The mobile station device is located in a range where communication with the relay station device is possible, and transmits a random access channel to the relay station device. The positional relationship between the relay station device and the base station device may be either the positional relationship shown in FIG. 10 or FIG. Prior to the start of the random access procedure of the mobile station device, the relay station device and the base station device have established a wireless connection (relay link) in advance and are synchronized with each other in radio frame.

The mobile station apparatus according to the present embodiment performs uplink synchronization with the relay station apparatus, not the base station apparatus. Further, the relay station device does not transmit the random access channel transmitted by the mobile station device to the base station device via the relay link. However, the present embodiment is characterized in that when uplink scheduling data (connection request message) is received, transmission to the base station apparatus via a relay link is started. The relay station device notifies the base station device of the occurrence of the connection request by transmitting the uplink scheduling data to the base station device during the random access procedure, and processes the random access in cooperation with the base station device. It is characterized by that.

In FIG. 7, the process until the mobile station apparatus transmits a connection request message using the radio resource indicated by the random access response is the same as FIG.

Also, it has a function of receiving a connection request message (uplink scheduling data) based on the uplink scheduling information indicated by the random access response. The relay station apparatus that has received the connection request message transmits the relay link connection request message to the base station apparatus (donor eNB) using the relay link (step S23). The relay link connection request message is transmitted using radio resources allocated in advance from the base station apparatus to the relay station apparatus. The relay link connection request message is transmitted to the base station device when the connection request message is received from the mobile station device, and is not transmitted at other timings.

The relay station device includes at least the following relay link connection request information in the relay link connection request message. (1) C-RNTI (or Temporary C-RNTI) of the mobile station apparatus that has made the connection request, (2) Connection request information notified by the connection request message. The connection request information notified in (2) is, for example, a connection request reason. Note that the control of the relay station apparatus can be simplified by including the connection request message as it is in the relay link connection request message.

The base station apparatus that has received the relay link connection request message determines that connection processing is in progress between the mobile station apparatus and the relay station apparatus that are notified by the relay link connection request message. Then, it is determined from the load status of the base station apparatus whether the mobile station apparatus can participate in the network. If it is determined that the mobile station apparatus can participate, a relay link connection completion message is transmitted to the relay station apparatus (step S24).

Also, the base station device arranges connection setting information (radio resource setting) in the connection setting message and transmits it to the relay station device (step S25). The relay station device transmits the received connection setting message to the mobile station device (step S15).

The mobile station apparatus that has received the connection setting message applies the radio resource setting indicated by the connection setting information, and transmits a connection setting completion message including the connection setting completion information to the relay station apparatus (step S16). Thereafter, Temporary C-RNTI is used as a normal C-RNTI. The relay station device that has received the connection setting completion message transmits the connection setting completion message to the base station device (step S26).

The base station device that has received the connection setting completion message generates a control message that follows the connection setting completion message based on the information notified by the connection setting completion message, and transmits it to the relay station device (step S27). The relay station apparatus that has received the control message transmits the control message to the mobile station apparatus (step S20). The control message transmitted in step S27 is, for example, a security setting message or a wireless connection reset message.

Each message transmission method (step S24, step S25, step S27) from the base station apparatus to the relay station apparatus may be transmitted using radio resources allocated in advance from the base station apparatus to the relay station apparatus. However, it may be transmitted by a radio resource (at least a downlink data channel scrambled by the relay station apparatus identifier) indicated by the downlink shared control channel in which the relay station apparatus identifier is arranged. The method for transmitting each message from the relay station device to the mobile station device (step S15, step S20) is the same as the normal EUTRA method. That is, the relay station apparatus transmits each message to the mobile station apparatus using the radio resource indicated by the downlink shared control channel in which C-RNTI is arranged.

The relay station device demodulates and decodes the received control message, recovers data errors that occur between the base station device and the relay station device, or between the mobile station device and the relay station device by error correction, An optimum scheduling is determined in consideration of inter-interference and the like, and the control message is re-encoded and re-modulated based on the scheduling.

It should be noted that the information of the connection setting message transmitted in step S15 of FIG. 7 and / or the information of the control message transmitted in step S20 are included in the relay link connection completion message in step S24 to thereby perform steps S25 to S25. Step S27 can be omitted. Similarly, step S27 can be omitted by including it in the connection setting message of step S25.

FIG. 8 is a sequence chart showing another example of the connection processing method according to Embodiment 2 of the present invention, and shows an example in which the relay link connection request is rejected by the base station device during the procedure of Contention based Random Access. . Conditions at the start of the random access procedure are the same as in FIG.

Since the relay station device that has received the connection request message of the mobile station device transmits the relay link connection request message using the relay link to the base station device (donor eNB), the description is the same as FIG. Abbreviated.

The base station apparatus that has received the relay link connection request message determines that a random access procedure is in progress between the mobile station apparatus and the relay station apparatus notified by the relay link connection request message. If the mobile station apparatus can participate in the network based on the load status of the base station apparatus and the like, if it is determined that participation is not possible (not permitted), a relay link connection request rejection message is transmitted to the relay station apparatus (Step S28).

The relay station apparatus that has received the relay link connection request rejection message determines that the relay link connection request has failed, and in order to notify the mobile station apparatus of the connection request failure, connection request rejection information is included in the connection request rejection message. Are transmitted (step S29). The connection request rejection information is, for example, a connection request rejection reason. Then, the information notified from the mobile station apparatus and the C-RNTI (or Temporary-RNTI) information allocated to the mobile station apparatus are deleted, and the random access procedure is terminated.

As the control message between the mobile station apparatus and the relay station apparatus shown in FIG. 7 or FIG. 8, a control message (RRC signaling) used in EUTRA can be used. For example, the RRCConnectionRequest or RRCConnectionReestablishmentRequest can be used as the connection request message. The connection setting message can use RRCConnectionSetup or RRCConnectionReestablishment.

Also, RRCConnectionSetupComplete or RRCConnectionReestablishmentComplete can be used for the connection setting completion message. As the security setting message, SecurityModeCommand can be used. For the connection request rejection message, RRCConnectionReject or RRCConnectionReestablishmentReject can be used.

Also, the control message between the base station apparatus and the relay station apparatus shown in FIG. 7 or FIG. 8 is preferably transmitted in a subframe reserved for transmitting relay station control data.

According to the present embodiment, the relay station device has a function of processing the same random access procedure as that of the base station device until a random access response is transmitted. Further, when the relay station device receives the connection request message, the relay station device transmits a relay link connection request message to the base station device to notify that the mobile station device newly requests to join the network. When the relay link connection request completion message is received, the connection setting message transmitted from the base station device is relayed to the mobile station device.

Also, since the relay station apparatus has a part of the function for processing the random access procedure, the delay time is shortened compared to the case where all the information related to random access is relayed to the base station apparatus. Therefore, even when the relay station apparatus is used, the processing time required for the connection process can be shortened. In addition, since the mobile station device connection request can be notified to the base station device during the random access procedure, if the base station device rejects the connection request, the subsequent connection processing is immediately stopped. It becomes possible to do. Since the mobile station apparatus and the relay station apparatus do not need to perform unnecessary connection processing, the use efficiency of radio resources is improved and the power consumption is reduced.

In the embodiment described above, the function of each unit of the mobile station apparatus and the base station apparatus or a program for realizing a part of these functions is recorded on a computer-readable recording medium, and the recording medium is recorded on this recording medium. The recorded program may be read into the computer system and executed to control the mobile station device or the base station device. Here, the “computer system” includes an OS and hardware such as peripheral devices.

Further, the “computer-readable recording medium” means a storage device such as a flexible disk, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, 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, it is also assumed that a server that holds a program for a certain time, such as a volatile memory inside a computer system that serves as a server or client. 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 the design and the like within the scope of the present invention are also claimed. Included in the range.

The present invention is suitable for application to mobile communication involving a relay station device.

DESCRIPTION OF SYMBOLS 100 ... Base station apparatus 200 ... Relay station apparatus 300 ...

Mobile station apparatus

101, 201, 301 ...

Reception part

102, 202, 302 ...

Demodulation part

103, 203, 303 ... Decoding

part

104, 204 ... Random

access processing part

105, 205 304,

upper layers

106, 206, 305 ...

control units

107, 207, 307 ... encoding

units

108, 208 ... reference

signal generation units

109, 209, 308 ...

modulation units

110, 210 ... multiplexing

units

111, 211, 309 ... transmission Unit 212 ... Control information selection unit 306 ... Random access generation unit AN11, AN21, AN31 ... Reception antenna AN12, AN22, AN32 ... Transmission antenna

Claims

A communication system comprising: a mobile station device; a relay station device connected to the mobile station device; and a control device that controls the relay station device and is connected to the mobile station device via the relay station device. A connection processing method,
The mobile station apparatus includes connection request information used in a connection request procedure between the mobile station apparatus and the control apparatus in a first connection request message for requesting connection from the mobile station apparatus to the relay station apparatus. Transmitting to the relay station device;
When the relay station apparatus transmits the response to the first connection request message to the mobile station apparatus when the connection request information is included in the first connection request message, the connection request information Generating a second connection request message including: and transmitting to the control device;
The control device determines whether to permit connection of the mobile station device based on connection request information included in the second connection request message, and transmits the response including a determination result to the relay station device And steps to
A connection processing method characterized by comprising:
The relay station device is a response to the first connection request message when the determination result indicates that the connection of the mobile station device is permitted, and the connection from the mobile station device to the relay station device 2. The connection processing method according to claim 1, further comprising a step of transmitting a connection setting message, which is a response indicating that permission is granted, to the mobile station apparatus.
The relay station device is a response to the first connection request message when the determination result indicates that the connection of the mobile station device is not permitted, and the connection from the mobile station device to the relay station device The connection processing method according to claim 1, further comprising a step of transmitting a connection request rejection message, which is a response indicating that the mobile station apparatus is rejected, to the mobile station apparatus.
The first connection request message including the connection request information is transmitted using a radio resource indicated by a random access response corresponding to a random access channel transmitted by the mobile station apparatus. The connection processing method described.
The connection processing method according to claim 1, wherein the control device is a base station device.
A communication system comprising: a mobile station device; a relay station device connected to the mobile station device; and a control device that controls the relay station device and is connected to the mobile station device via the relay station device. A relay station device,
When the connection request information used in the connection request procedure between the mobile station device and the control device is included in the first connection request message for requesting connection from the mobile station device to the relay station device, A control unit configured to generate a second connection request message including the connection request information and transmit the response to the control device before transmitting a response to the first connection request message to the mobile station device; The relay station apparatus characterized by this.