JP2008017195A - Multiband radio communication system, mobile station device, and random access method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multiband radio communication system capable of performing random access with a superior response time. <P>SOLUTION: The multiband radio communication system comprises a base station device and a mobile station device which performs random access to the base station device with a frequency bandwidth larger than a predetermined frequency bandwidth. When failing in random access using one frequency band, the mobile station device performs random access again by using a frequency band selected out of frequency bands with which the mobile station can communicate in the state of the failure. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a multiband radio communication system, a mobile station apparatus, and a random access method, and in particular, a multiband radio communication system, a mobile station, in which mobile station apparatuses having different communication bandwidths are mixed and these mobile station apparatuses perform random access The present invention relates to an apparatus and a random access method.

  In 3GPP (3rd Generation Partnership Project), a W-CDMA (Wideband-Code Division Multiplexing Access) method is standardized as a third generation cellular mobile communication method, and services are started sequentially. Also, HSDPA (High Speed Downlink Packet Access), which further increases the communication speed, has been standardized and the service is about to start.

  On the other hand, in 3GPP, the evolution of third generation radio access technology (Evolved Universal Terrestrial Radio Access, hereinafter referred to as EUTRA) is being studied. An OFDMA (Orthogonal Frequency Division Multiplexing Access) scheme has been proposed as an EUTRA downlink communication scheme. As the EUTRA technology, there is a technology such as an adaptive modulation and coding scheme (AMCS) based on adaptive radio link control (link adaptation) such as channel coding in the OFDMA scheme. Has been applied. In order to efficiently perform high-speed packet data transmission, the AMCS method is an error correction method, an error correction coding rate, a data modulation multi-value number, a time / frequency axis according to the propagation path condition of each mobile station apparatus. This is a method of switching radio transmission parameters (hereinafter referred to as AMC mode) such as a spreading factor (SF) and the number of multicode multiplexing. For example, for data modulation, as the propagation path condition becomes better, switching from QPSK (Quadrature Phase Shift Keying) modulation to multi-level modulation method with higher modulation efficiency such as 8PSK modulation, 16QAM (Quadrature Amplitude Modulation) modulation, etc. Thus, the maximum throughput of the mobile communication system can be increased.

  In addition, various proposals such as a multicarrier communication system and a single carrier communication system have been proposed for the uplink of EUTRA, and the ratio of peak power to average power (PAPR) is higher than the multicarrier communication system such as the OFDM system. VSCRF (Variable Spreading and Chip Repetition Factors) -excellent characteristics of CDMA), CDMA, IFDMA (Interleaved Frequency Division Multiple-Access), DFT (Discrete Fourier Link) It has been proposed as a wireless communication system. In addition, it has been proposed to apply time / frequency scheduling in which a communication channel is allocated to a mobile station apparatus in accordance with propagation path conditions in the time domain / frequency domain in the downlink and uplink.

FIG. 18 shows an uplink / downlink channel configuration based on the proposal in 3GPP for EUTRA.
The downlink of EUTRA includes a downlink pilot channel DPICH (Downlink Pilot Channel), a downlink synchronization channel DSCH (Downlink Synchronization Channel), a downlink common control channel DCCCH (Downlink Common Control Channel control), and a downlink common channel control. It is composed of a Shared Control Signaling Channel) and a downlink shared data channel DSDCH (Downlink Shared Data Channel) (Non-patent Document 1).

  The uplink of EUTRA is configured by an uplink pilot channel UPICH (Uplink Pilot Channel), an uplink contention base channel CBCH (Contention-based Channel), and an uplink scheduling channel USCH (Uplink Scheduling Channel) (non-patent literature). 2).

  In the downlink of EUTRA, the downlink pilot channel DPICH includes a downlink common pilot channel DCPICH (Downlink Common Pilot Channel) and a downlink dedicated pilot channel DDPICH (Downlink Dedicated Pilot Channel). The downlink common pilot channel DCPICH corresponds to a pilot channel CPICH (Common Pilot Channel) of the W-CDMA scheme, and is used for downlink data channel demodulation, downlink AMCS scheme and time / frequency scheduling. Used for estimation of radio propagation path characteristics, cell search, propagation path loss measurement for uplink transmission power control, and reception quality measurement of other cells for handover. The downlink dedicated pilot channel DDPICH is transmitted to an individual mobile station apparatus from an antenna having a different radio propagation path characteristic from a cell shared antenna such as an adaptive array antenna, or to a mobile station apparatus having low reception quality as necessary. For the purpose of reinforcing the downlink common pilot channel DCPICH.

  The downlink synchronization channel DSCH corresponds to a synchronization channel SCH (Synchronization Channel) of the W-CDMA system, cell search of mobile station apparatus, carrier frequency offset of OFDM signal, frame, time slot TTI (Transmission Time Interval), OFDM symbol Used for timing synchronization. Further, the downlink synchronization channel DSCH may be composed of two types of synchronization channels, P-SCH (Primary-SCH) and S-SCH (Secondary-SCH).

  The downlink common control channel DCCCH is a W-CDMA first common control physical channel P-CCPCH (Primary-Common Control Physical Channel), a second common control physical channel S-CCPCH (Secondary-Common Control Physical Channel), and It includes common control information such as broadcast information corresponding to a paging indicator channel PICH (Paging Indicator Channel), paging indicator PI (Paging Indicator) information, paging information, and downlink access information.

The downlink shared control signaling channel DSCSCH corresponds to a control information channel of a high-speed physical downlink shared channel HS-PDSCH (High Speed Shared Physical Channel) of the HSDPA system, and is shared by a plurality of mobile station apparatuses, and each mobile station apparatus Information necessary for demodulation of the high-speed downlink shared channel HS-DSCH (High Speed-Downlink Shared Channel) (modulation scheme, spreading code, etc.), information necessary for error correction decoding processing and HARQ (Hybrid Automatic Repeat Request) processing, and It is used to transmit scheduling information (user ID, radio resource arrangement) of radio resources (frequency, time).
The downlink shared data channel DSDCH corresponds to the packet data channel of the high-speed physical downlink shared channel HS-PDSCH of the HSDPA method, and is used for transmission of packet data addressed to the mobile station apparatus from the upper layer.

  In the uplink, the uplink contention base channel CBCH includes a random access channel RACH (Random Access Channel), a fast access channel FACH (Fast Access Channel), an uplink request channel URCH (Uplink Request Channel), and an uplink synchronization channel ( (Uplink synchronization channel). This corresponds to a random access channel RACH (Random Access Channel) of the W-CDMA system. Here, the same name and random access channel RACH are used in both EUTRA and W-CDMA, but the EUTRA random access channel RACH is mainly used for the initial wireless connection of the mobile station apparatus or the reconnection during communication. This refers to a channel used for processing or the like (hereinafter, random access channel RACH refers to EUTRA random access channel RACH). In this specification, transmission of each channel in the uplink contention base channel CBCH is collectively referred to as random access.

  The uplink scheduling channel USCH is composed of an uplink shared control channel USCCH (Uplink Shared Control Channel) and an uplink shared data channel USDCH (Uplink Shared Data Channel), and is an uplink dedicated data channel DPDCH (Dedicated Physic Physic) of the W-CDMA system. Channel) and the HS-DSCH-related uplink dedicated physical control channel HS-DPCCH (Dedicated Physical Control Channel for HS-DSCH) of the HSDPA method, each mobile station device is shared, transmission of packet data of the mobile station device, CQI (Channel Quality I) of downlink channel quality Dicator) Information, HARQ (Hybrid Automatioc Repeat reQuest) feedback information, such as used to transmit such uplink channel control information.

  The uplink pilot channel UPICH is used for uplink data channel demodulation, uplink AMCS scheme, and estimation of uplink radio channel characteristics for time / frequency scheduling.

FIG. 19 shows a configuration example of a downlink frame based on the proposal of 3GPP for EUTRA.
The downlink frame is configured in two dimensions by a chunk (chunk Chunk_1 to chunk Chunk_m) that is a group of subcarriers on the frequency axis and a time slot TTI (time slot TTI_1 to time slot TTI_n) on the time axis. The chunk is composed of a plurality of subcarriers. For example, on the frequency axis, the frequency bandwidth (system bandwidth) BW of the entire downlink system band managed by the base station apparatus is 20 MHz, and the chunk frequency bandwidth (chunk) (Bandwidth) When Bch is 1.25 MHz and subcarrier frequency bandwidth (subcarrier bandwidth) Bsc is 12.5 kHz, the downlink is composed of 16 chunks and 100 subcarriers in one chunk. In total, 1600 subcarriers are included. On the time axis, when one frame is 10 ms and the time slot TTI is 0.5 ms, 20 time slots TTI are included. That is, one frame includes 16 chunks, 20 time slots TTI, and one time slot TTI includes a plurality of OFDM symbols. When the OFDM symbol length Ts is 0.05 ms, 10 OFDM symbols are included in one time slot TTI. Therefore, in this example, the minimum radio resource unit that can be used by the mobile station apparatus is configured by one chunk (100 subcarriers) and one time slot TTI (0.5 ms). Further, the radio resource of one chunk can be further divided and the divided frequency bandwidth (resource bandwidth) can be used as a unit of AMCS scheme and frequency scheduling. A resource configured by this unit is called a resource block.

  As shown in FIG. 19, the downlink common pilot channel DCPICH is mapped to the head of each time slot TTI. The downlink dedicated pilot channel DDPICH is mapped to an appropriate position in one time slot TTI when necessary according to the antenna usage status of the base station device or the propagation path status of the mobile station device (for example, the time slot TTI). To the center of the).

  The downlink common control channel DCCCH and the downlink synchronization channel DSCH are mapped to the first time slot TTI of the frame (for example, the downlink common control channel DCCCH is mapped after the downlink common pilot channel DCPICH, and the downlink synchronization channel DSCH). Is mapped to the end of the time slot TTI). By mapping to the frame start time slot TTI, when the mobile station apparatus is in the idle mode, if only the frame start time slot TTI or several OFDM symbols in the frame start time slot TTI are received, cell search, timing synchronization, Common control information such as broadcast information and paging information can be received. In the idle mode, the mobile station apparatus can operate with intermittent reception IR (Intermittent Reception).

  The downlink shared control signaling channel DSCSCH is mapped to the front part of each time slot TTI in the same manner as the downlink common pilot channel DCPICH (for example, in the first time slot TTI of the frame, the downlink shared control signaling channel DSCSCH is the downlink common pilot). Mapping is performed after the downlink common control channel DCCCH following the channel DCPICH, and in the other time slots TTI, the downlink shared control signaling channel DSCSCH is mapped after the downlink common pilot channel DCPICH). Even when the mobile station apparatus is performing packet communication, if there is no packet data addressed to itself in each time slot TTI, intermittent reception is possible in which only the downlink shared control signaling channel DSCSCH is received.

  The downlink shared data channel DSDCH is divided in units of chunks, assigned a channel based on the propagation path status of each mobile station apparatus, and transmits packet data addressed to each mobile station apparatus. As an example, as shown in FIG. 19, in time slot TTI_1, a channel is assigned to mobile station device MS1 to chunk Chunk_1, mobile station device MS2 to chunk Chunk_2, and mobile station device MS3 to chunk Chunk_3.

  As shown in FIG. 19, channels are allocated to one mobile station apparatus in units of one chunk in the time slot of time slot TTI_1 and time slot TTI_2, and a plurality of mobile station apparatuses with good propagation path characteristics are provided. Scheduling method for allocating channels to multiple chunks and improving the overall system throughput using the multi-user diversity effect, and a mobile station for multiple chunk units and sub-time slot TTI units in a time slot By assigning channels to devices, mobile station devices with poor radio propagation characteristics due to cell boundaries, high-speed movement, etc. can be received using the frequency diversity effect by having a wide frequency bandwidth across multiple chunks. Frequency scheduling methods that improve characteristics have been proposed.

FIG. 20 shows a configuration example of an uplink frame based on the proposal of 3GPP for EUTRA.
The uplink frame is configured in two dimensions by a chunk (chunk Chunk_1 to chunk Chunk_m) that is a cluster of a plurality of subcarriers on the frequency axis and a time slot TTI (time slot TTI_1 to time slot TTI_n) on the time axis. For example, on the frequency axis, the frequency bandwidth (system bandwidth) BW of the entire uplink system band managed by the base station apparatus is 20 MHz, and the frequency bandwidth (chunk bandwidth) Bch of each chunk is 1.25 MHz. In this case, the uplink frequency axis is composed of 16 chunks. On the time axis, when one frame is 10 ms and the time slot TTI is 0.5 ms, 20 time slots TTI are included. That is, a single frame includes a plurality of symbols in 16 chunks, 20 time slots TTI, and 1 time slot TTI. Therefore, in this example, the minimum radio resource unit that can be used by the mobile station apparatus is configured by one chunk (1.25 MHz) and one time slot TTI (0.5 ms). Further, the radio resource of one chunk can be further divided and the divided frequency bandwidth (resource bandwidth) can be used as a unit of AMCS scheme and frequency scheduling. A resource configured by this unit is called a resource block.

  As shown in FIG. 20, the uplink pilot channel UPICH is mapped to the beginning and end of each time slot TTI of the uplink scheduling channel USCH. Here, the arrangement of the uplink pilot channel UPICH is only shown as an example, and may be configured to be mapped to another arrangement. The base station apparatus estimates a radio propagation path from the uplink pilot channel UPICH from each mobile station apparatus and detects a reception timing shift between the mobile station apparatus and the base station apparatus. Each mobile station apparatus can simultaneously transmit the uplink pilot channel UPICH using Distributed FDMA (comb-tooth spectrum), Localized FDMA (localized spectrum), or CDMA.

  As shown in FIG. 21, the uplink contention base channel CBCH and the uplink scheduling channel USCH are divided into TDM (arranged by time division multiplexing: FIG. 21 (b)) and a TDM-FDM hybrid method (time division multiplexing and frequency division multiplexing). Are combined and mapped in FIG. 21 (a)). In addition to the uplink contention base channel CBCH multiplexing method as shown in FIG. 22, the base station device designates the uplink contention base channel CBCH band to the managed mobile station device as broadcast information, It has been proposed that the mobile station apparatus performs random access using a part of the chunk in the band of the uplink contention base channel CBCH designated (Non-patent Document 3).

  In the case of FIG. 22, the base station apparatus designates the mobile station apparatuses A, B, C, D, E, and F to use the CBCH frequency band A as the uplink contention base channel CBCH. Randomly selects a chunk to be randomly accessed within the frequency band A for CBCH. Here, a case is shown in which the frequency bandwidth used by one mobile station apparatus for random access is 1.25 MHz. In addition, since the mobile station apparatus randomly selects the frequency bandwidth, there may be a plurality of mobile station apparatuses that select the same chunk. In FIG. 22, with reference to the frequency band A for CBCH, the mobile station device A selects the leftmost chunk, the mobile station device B selects the second chunk from the right end, and the mobile station device C is the third chunk from the left end. The mobile station apparatus E has selected the rightmost chunk, and the mobile station apparatuses D and F have selected the same fourth chunk from the right end.

  When the uplink contention base channel CBCH is divided in units of chunks and there is user data or control data that is not scheduled from the base station apparatus, each mobile station apparatus uses Distributed FDMA, Localized FDMA, or CDMA, Data is transmitted using the uplink contention base channel CBCH.

Next, the random access channel RACH mainly targeted by the present invention will be described.
Random access channel RACH used for initial connection establishment or reconnection processing during communication is one of the main purposes to match the reception timing with each mobile station device at the base station device antenna end, A method of transmitting only the preamble part for measuring a reception timing shift between the base station apparatus and the mobile station apparatus for each mobile station apparatus, and a reception timing shift between the base station apparatus and the mobile station apparatus for each mobile station apparatus A method of transmitting a preamble part for measurement and a payload part including information necessary for wireless connection control has been proposed (Non-patent Documents 3 and 4). In any method, information for identifying the mobile station apparatus is also included in the random access channel RACH.

In these documents, in the random access of the random access channel RACH, a specific example of a method of specifying a frequency position used by the mobile station device in the CBCH frequency band is not shown, but a method of randomly selecting a chunk It has been known.
In this method, when the mobile station apparatus attempts random access of the random access channel RACH to establish an initial connection, the mobile station apparatus determines which chunk is the most vacant or receives inter-user interference between the mobile station apparatuses. Since it is not known whether is small, a random random channel of the random access channel RACH is selected using a statistical random algorithm. At this time, random access concentrates on the selected chunk and a collision occurs between the mobile station apparatuses. Since the random access channel RACH from the mobile station apparatus is not correctly detected in the base station apparatus, a response to the mobile station apparatus is not received. There may not be. In such a case, considering the randomization, the mobile station apparatus shifts from the initially selected chunk and selects another chunk to try random access. As a result, the number of users attempting random access of the random access channel RACH is distributed for each chunk so that the collision probability is not partially biased.

  The uplink scheduling channel USCH is divided into chunks, the base station device assigns a channel based on the channel conditions of each mobile station device, and each mobile station device to which the channel is assigned sends packet data to the base station device. Send. As an example, as shown in FIG. 20, in time slot TTI_1, a channel is assigned to mobile station device MS1 to chunk Chunk_1, mobile station device MS3 to chunk Chunk_2, and mobile station device MS4 to chunk Chunk_3.

  As a scheduling method for assigning a channel to a chunk to a mobile station apparatus according to the radio propagation path status of each mobile station apparatus performed for the uplink scheduling channel USCH, a chunk band in the frequency domain is determined in advance. A time domain channel-dependent scheduling using pre-assigned frequency bandwidth and a method for performing scheduling for both the frequency domain and the time domain. Scheduling according to the radio propagation path situation of the station apparatus (Frequency and time domain channel-dependent scheduling), Hybrid method of the above two methods have been proposed (Non-Patent Document 5).

Also, EUTRA technical requirements (Non-Patent Document 6) have been proposed, spectrum flexibility (Spectrum Flexibility) is required for integration and coexistence with existing 2G and 3G services, and spectrums of different sizes (for example, 1 Support for spectrum allocation of different sizes (for example, 1.25 MHz, 2.5 MHz, 5 MHz, 10 MHz) is required for .25 MHz, 2.5 MHz, 5 MHz, 10 MHz, 20 MHz) , 20 MHz), and the mobile station class mobile station apparatus having a transmission / reception capability is also requested.
R1-050707 “Physical Channel and Multiplexing in Evolved UTRA Downlink”, 3GPP TSG RAN WG1 Meeting # 42 London, UK, August 29-September 2, 2005 R1-050850 “Physical Channel and Multiplexing in Evolved UTRA Uplink”, 3GPP TSG RAN WG1 Meeting # 42 London, UK, August 29-September 2, 2005 R1-051391 “Random Access Transmission for Scalable Multiple Bandwidth in Evolved UTRA Uplink”, 3GPP TSG RAN WG1 Meeting # 43 Seoul, Kore5, Korea 7 R1-051445 “E-UTRA Random Access”, 3GPP TSG RAN WG1 Meeting # 43 Seoul, Korea, November 7-11, 2005 R1-050701 “Channel-Dependent Scheduling Method for Single-Carrier FDMA Radio Access in Evolved UTRA Uplink”, 3GPP TSG RAN WG1 Meet # 42 L 3GPP TR (Technical Report) 25.913, V7.2.0 (2005-12), Requirements for Evolved UTRA (E-UTRA) and Evolved UTRAN (E-UTRAN)

  However, a mobile station apparatus with a narrow bandwidth that can transmit only the minimum frequency bandwidth of random access must change the oscillation frequency of the local oscillator in order to shift the chunk. At this time, a control delay for setting a change from the digital unit to the analog unit and a delay until the fluctuation of the oscillation frequency of the local oscillator is stabilized occur, and it takes time to resume transmission. . For this reason, if a mobile station device with a narrow bandwidth performs random access and a collision occurs between mobile station devices, it takes time to shift the chunk and retry the random access. There is a problem that the response time from when the access is made to when the random access is successful deteriorates.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a multiband radio communication system capable of performing random access with excellent response time.

  The present invention has been made to solve the above-described problems, and a multiband wireless communication system according to the present invention includes a base station apparatus and a random access to the base station apparatus with a frequency bandwidth equal to or greater than a predetermined frequency bandwidth. In a multiband wireless communication system comprising a mobile station device that performs communication, when the mobile station device fails in random access using one frequency band, the frequency that can be communicated in the state of the device at the time of the failure Random access is performed again using a frequency band selected from the bands.

  Thus, in the multiband wireless communication system of the present invention, when the mobile station apparatus retransmits random access, the mobile station apparatus does not need to change the oscillation frequency that requires a long time. If a failure is detected, the random access can be immediately retransmitted. For this reason, the multiband radio | wireless communications system of this invention can perform the random access of the outstanding response time.

  The multiband wireless communication system of the present invention is the above-described multiband wireless communication system, wherein the frequency bandwidth of the communication capability of the mobile device is the same as the predetermined frequency bandwidth. When the random access using the first frequency band fails, the first mobile station apparatus that performs the random access again uses the first frequency band, and among the mobile station apparatuses, the first mobile station apparatus When the second mobile station device having a frequency bandwidth of communication capability included in the mobile station device wider than the predetermined frequency bandwidth fails in the random access using the second frequency band, the state of the own device at the time of the failure In this case, random access is performed again using a frequency band that is communicable with the second frequency band and is different from the second frequency band.

  As a result, in the multiband wireless communication system of the present invention, the random access between the first mobile station device and the second mobile station device collided, and the random access of both failed because the base station device could not detect it. Sometimes the first and second mobile station apparatuses do not collide because they retransmit random access in different frequency bands. For this reason, the multiband radio | wireless communications system of this invention can perform the random access of the outstanding response time.

  The multiband radio communication system according to the present invention is the multiband radio communication system described above, and when the mobile station apparatus fails in random access using one frequency band, Random access is performed again using a frequency band that is communicable in the state of the apparatus, and that uses a frequency band outside the frequency band that can be communicated by the mobile station apparatus whose frequency bandwidth of communication capability is narrower than the self apparatus. .

  Thereby, in the multiband wireless communication system of the present invention, the random access transmitted by the mobile station device collides with the random access transmitted by the mobile station device whose frequency bandwidth of communication capability is narrower than the mobile station device, When the base station apparatus fails to detect both random accesses and fails, these mobile station apparatuses retransmit the random access in different frequency bands, so there is no collision. For this reason, the multiband radio | wireless communications system of this invention can perform the random access of the outstanding response time.

  The multiband wireless communication system of the present invention is the above-described multiband wireless communication system, and the mobile station device is selected based on the frequency bandwidth of its own communication capability when starting random access. The frequency of the local oscillator of the own device is set as the frequency, and the mobile station device is a frequency band in which communication is possible in the state of the local oscillator, and the frequency bandwidth of the communication capability is narrower than the own device. Random access is performed using a frequency band outside the communicable frequency band when the frequency of the local oscillator of the mobile station apparatus is set to a frequency selected based on the frequency bandwidth of the communication capability. .

  Thereby, in the multiband wireless communication system of the present invention, the random access transmitted by the mobile station device collides with the random access transmitted by the mobile station device whose frequency bandwidth of communication capability is narrower than the mobile station device, When the base station apparatus fails to detect both random accesses and fails, these mobile station apparatuses retransmit the random access in different frequency bands, so there is no collision. For this reason, the multiband radio | wireless communications system of this invention can perform the random access of the outstanding response time.

  The multiband radio communication system of the present invention is any one of the multiband radio communication systems described above, wherein the mobile station apparatus performs random access to a frequency band selected based on identification information unique to the mobile station apparatus. It is used when performing again.

  Thereby, in the multiband wireless communication system of the present invention, the random access transmitted by the mobile station device collides with the random access transmitted by the mobile station device having the same frequency bandwidth of the communication capability as the mobile station device, When the base station apparatus fails to detect both random accesses, these mobile station apparatuses retransmit the random access in the frequency band selected based on the identification information unique to the own apparatus. The probability of selecting and colliding again can be averaged, and the probability of extremely colliding increases, so that retransmission is repeated and it does not take a long time to succeed in random access. For this reason, the multiband radio | wireless communications system of this invention can perform the random access of the outstanding response time.

  The multiband radio communication system of the present invention is a multiband radio communication system comprising a base station apparatus and a mobile station apparatus that performs random access to the base station apparatus with a frequency bandwidth equal to or greater than a predetermined frequency bandwidth. The mobile station device selects a frequency band used for random access based on the frequency bandwidth of the communication capability of the mobile device.

  As a result, the multiband wireless communication system of the present invention can reduce the frequency bandwidth of communication capability by selecting different frequency bands and using them for random access in mobile station apparatuses having different frequency bandwidths of communication capability. Since random access does not collide between different mobile station apparatuses, random access with excellent response time can be performed.

  A multiband radio communication system according to the present invention is the multiband radio communication system described above, wherein the mobile station device sets a frequency of a local oscillator of its own device to a predetermined frequency when starting random access. The frequency band used for random access is selected from frequency bands that can be communicated in the state of the local oscillator.

  As a result, in the multiband wireless communication system of the present invention, when the mobile station apparatus performs random access, the mobile station apparatus does not need to change the oscillation frequency that requires a long time, so the mobile station apparatus performs random access immediately. Random access with excellent response time.

  The multiband radio communication system of the present invention is any one of the multiband radio communication systems described above, wherein the mobile station apparatus uses a frequency band used for random access as identification information unique to the mobile station apparatus. It is characterized by choosing based on.

  Thereby, in the multiband radio communication system of the present invention, the mobile station apparatus transmits random access in the frequency band selected based on the identification information unique to the mobile station apparatus. The probability of collision can be averaged, and the retransmission is repeated due to the extremely high probability of collision, so that it does not take a long time to succeed in random access. For this reason, the multiband radio | wireless communications system of this invention can perform the random access of the outstanding response time.

  The multiband radio communication system of the present invention is any one of the multiband radio communication systems described above, wherein the mobile station apparatus uses a frequency band for random access based on a frequency bandwidth of its own communication capability. It is characterized by selecting.

  The multiband radio communication system of the present invention is any one of the multiband radio communication systems described above, and when the mobile station apparatus starts random access, the frequency of the local oscillator of its own apparatus is set to a predetermined frequency. Is selected, and a frequency band used for random access is selected from frequency bands that can be communicated in the state of the local oscillator.

  The multiband radio communication system of the present invention is any one of the multiband radio communication systems described above, wherein the mobile station apparatus uses a frequency band used for random access as identification information unique to the mobile station apparatus. It is characterized by choosing based on.

  In addition, the mobile station device of the present invention, in a mobile station device that performs random access to the base station device with a frequency bandwidth greater than or equal to a predetermined frequency bandwidth, when random access using one frequency band fails, Random access is performed again using a frequency band selected from the frequency bands that can be communicated in the state of the device itself when the failure occurs.

  Further, the mobile station apparatus of the present invention can perform random access based on the frequency bandwidth of the communication capability of the mobile station apparatus that performs random access to the base station apparatus with a frequency bandwidth equal to or greater than a predetermined frequency bandwidth. Select the frequency band to be used.

  Further, the random access method of the present invention provides a random access in a multiband radio communication system comprising a base station apparatus and a mobile station apparatus that performs random access to the base station apparatus with a frequency bandwidth equal to or greater than a predetermined frequency bandwidth. In the method, when the mobile station apparatus fails in random access using one frequency band, the mobile station apparatus randomly uses a frequency band selected from the frequency bands communicable in the state of the own apparatus at the time of the failure. It is characterized by comprising a first process of performing access again.

  Further, the random access method of the present invention provides a random access in a multiband radio communication system comprising a base station apparatus and a mobile station apparatus that performs random access to the base station apparatus with a frequency bandwidth equal to or greater than a predetermined frequency bandwidth. In the method, the mobile station device includes a first step of selecting a frequency band used for random access based on a frequency bandwidth of the communication capability of the mobile device.

  According to the present invention, in the multiband radio communication system of the present invention, when the mobile station apparatus retransmits random access, the mobile station apparatus does not need to change an oscillation frequency that requires a long time. Upon detecting a random access failure, it can immediately retransmit the random access. For this reason, the multiband radio | wireless communications system of this invention can perform the random access of the outstanding response time.

  Hereinafter, first to third embodiments of the present invention will be described with reference to the drawings. First, contents common to these embodiments will be described. FIG. 1 is a schematic block diagram illustrating a configuration of a multiband wireless communication system common to the embodiments. BS is a base station apparatus. MS1 to MS4 are mobile station apparatuses having different communication bandwidths for their communication capabilities. The downlink in each embodiment is the downlink pilot channel DPICH, the downlink synchronization channel DSCH, the downlink common control channel DCCCH, the downlink shared control signaling channel DSCSCH, and the downlink shared data, as in EUTRA studied in 3GPP. It consists of channel DSDCH. The uplink in each embodiment includes an uplink uplink contention base channel CBCH, an uplink scheduling channel USCH, and an uplink pilot channel UPICH, similar to EUTRA studied in 3GPP.

FIGS. 2 and 3 are configuration examples of an uplink frame in each embodiment. Similarly to EUTRA studied in 3GPP, an uplink contention base channel CBCH and an uplink scheduling channel USCH are frequency / time division multiplexed. Has been.
As shown in the configuration example of FIG. 2, the uplink frame is based on a chunk (chunk Chunk_1 to chunk Chunk_m) that is a group of a plurality of subcarriers on the frequency axis and a time slot TTI (time slot TTI_1 to time slot TTI_n) on the time axis. Consists of two dimensions. Further, the radio resource of one chunk can be further divided and the divided frequency bandwidth (resource bandwidth) can be used as a unit of AMCS scheme and frequency scheduling. A resource configured by this unit is called a resource block.

  As shown in FIG. 2, the uplink pilot channel UPICH is mapped to the beginning and end of each time slot TTI of the uplink scheduling channel USCH. Here, the arrangement of the uplink pilot channel UPICH is only shown as an example, and may be configured to be mapped to another arrangement. The base station apparatus BS estimates a radio propagation path from the uplink pilot channel UPICH from each mobile station apparatus MS1 to MS4 and detects a reception timing shift between the mobile station apparatuses MS1 to MS4 and the base station apparatus BS. Each mobile station apparatus MS1 to MS4 can simultaneously transmit the uplink pilot channel UPICH using Distributed FDMA (comb-toothed spectrum), Localized FDMA (localized spectrum), or CDMA.

  As shown in FIG. 3, the uplink contention base channel CBCH and the uplink scheduling channel USCH are divided into TDM (arranged in time division multiplexing: FIG. 3 (b)) and a TDM-FDM hybrid method (time division multiplexing and frequency division multiplexing). Is used in combination with: frequency / time division multiplexing in FIG.

FIG. 4 is a schematic block diagram showing a configuration of mobile station apparatuses MS1 to MS4.
The mobile station devices MS1 to MS4 include a transmission unit 100, a reception unit 110, a radio control unit 120, and a radio unit 130. The transmission unit 100 includes a channel coding unit 101, a data control unit 102, a modulation unit 103, a scheduling unit 106 including a USCH scheduling unit 104 and a CBCH scheduling unit 105, and a transmission timing control unit 107. The reception unit 110 includes an OFDM demodulation unit 111, a channel estimation unit 112, a control data extraction unit 113, and a channel decoding unit 114. Note that the radio control unit 120 and the radio unit 130 are shared for transmission and reception.

First, a configuration related to transmission will be described.
The channel encoding unit 101 encodes the input transmission data using the encoding rate of the AMC information input from the scheduling unit 106.

  The data control unit 102 transmits the downlink CQI information, the input control data, and the transmission data encoded by the channel encoding unit 101, based on an instruction from the scheduling unit 106, the uplink scheduling channel USCH, the uplink configuration. A channel is arranged in a transmission frame so as to be transmitted by the tension base channel CBCH. The data control unit 102 also arranges the uplink pilot channel UPICH.

  Modulation section 103 modulates data using the modulation scheme of AMC information input from scheduling section 106 to generate modulation data. Further, the modulation unit 103 performs FFT (Fast Fourier Transform) on the modulated data, maps the modulated data and the null data that are FFTed to the subcarrier based on the mapping information from the scheduling unit 106, An IFFT (Inverse Fast Fourier Transform) is performed to generate single carrier modulation data. For convenience of explanation, a case where DFT-Spread OFDM is used as an uplink communication method is described here, but other single carrier methods such as VSCRF-CDMA and multicarrier methods such as OFDM may be used. .

  The scheduling unit 106 determines a modulation method based on the AMC information notified from the control data extraction unit 113, and further, based on the channel type specified in the schedule information and the modulation method determined in advance, each data is transmitted to which channel on the frame. Decide what to place in. The channel arrangement on the frame is acquired from the control data extraction unit 113 as schedule information. Further, the scheduling unit 106 includes a USCH scheduling unit 104 and a CBCH scheduling unit 105. The transmission data, control data, and CQI information to be transmitted on the uplink scheduling channel USCH are determined by the USCH scheduling unit 104, and the transmission data and control data to be transmitted on the uplink contention base channel CBCH are CBCH scheduling unit 105. To decide.

  Also, the CBCH scheduling unit 105, when a response to the data transmitted on the uplink contention base channel CBCH is not obtained from the control data extracting unit 113 even after a lapse of a certain time after transmitting the data, Decide which channel on the frame to place the data. Details of the method for determining the channel to be arranged at this time will be described in the description of each embodiment.

  Transmission timing control section 107 outputs single carrier modulation data to radio section 130 based on transmission timing information input from control data extraction section 113.

  The radio unit 130 sets the oscillation frequency of the local oscillator in the radio unit 130 based on the radio frequency information input from the radio control unit 120, and an oscillation signal generated by the local oscillator using the input single carrier modulation data. Is up-converted to a radio frequency signal and transmitted from an antenna (not shown) to the base station apparatus BS.

Next, a configuration related to reception will be described.
Radio section 130 receives downlink data from base station apparatus BS via an antenna, down-converts it into a baseband signal, and outputs it to OFDM demodulation section 111 and channel estimation section 112.

  Channel estimation section 112 estimates the propagation path characteristics from the received data corresponding to downlink pilot channel DPICH, and outputs the propagation path characteristics estimated value to OFDM demodulation section 111. Further, in order to notify the reception status to the base station apparatus BS, CQI information is generated based on the propagation path characteristic estimation value, and the CQI information is output to the data control unit 102 and the scheduling unit 106.

  The OFDM demodulator 111 compensates for the propagation path fluctuation of the received data based on the propagation path characteristic estimation value input from the channel estimator 112, and receives the received data based on the AMC information input from the control data extractor 113. Demodulate.

  The control data extraction unit 113 separates the received data into information data and control data (downlink common control channel DCCCH, downlink shared control signaling channel DSCSCH). The control data extraction unit 113 outputs the AMC information for the downlink information data in the control data to the OFDM demodulation unit 111 and the channel decoding unit 114, and the uplink AMC information and scheduling information (channel on the frame) Are arranged in the scheduling unit 106.

  Also, uplink transmission timing information in the control data is output to transmission timing control section 107. The channel decoding unit 114 decodes the demodulated data from the AMC information of the information data input from the control data extraction unit 113, and outputs the decoded data to the upper layer. In addition, predetermined AMC is set in advance for the control data, the OFDM demodulator 111 demodulates the control data by a predetermined modulation method set in advance, and the channel decoder 114 for the control data Performs decoding at a predetermined coding rate set in advance. In FIG. 4, illustration of the channel coding unit and the channel decoding unit for control data is omitted. The radio control unit 120 selects the center frequency of the uplink and downlink use frequency bands, and outputs radio frequency information to the radio unit 130.

  Next, details of the modulation unit 103 will be described. Thus, processing for changing the transmission frequency band (chunk) without changing the oscillation frequency of the local oscillator in the radio unit 130 will be described. In the present embodiment, the modulation unit 103 performs modulation processing in DFT-Spread OFDM. FIG. 5 is a schematic block diagram illustrating a configuration of a processing unit that generates a DFT-Spread OFDM modulation signal of the modulation unit 103. The modulation unit 103 includes an AMC modulation unit 300, an FFT unit 301 for 1.25 MHz that is an FFT unit for each frequency band used, an FFT unit 302 for 2.5 MHz,... An FFT unit 304 for 10 MHz, a subcarrier mapping unit 310, An IFFT unit 320 is provided.

The AMC modulation unit 300 modulates the data input from the data control unit 102 using the modulation scheme of the AMC information input from the scheduling unit 106 to generate modulation data.
The 1.25 MHz FFT unit 301, the 2.5 MHz FFT unit 302,... 10 MHz FFT unit 304 are selected according to the frequency band used for data transmission, and the modulation data generated by the AMC modulation unit 300 is processed at high speed. Modulation data subjected to Fourier transform and Fourier transformed to subcarriers (that is, coefficients of each frequency obtained as a transformation result) is output to subcarrier mapping section 310. For example, when the frequency band used for data transmission is 1.25 MHz of one chunk, the 1.25 MHz FFT unit 301 is selected, and the 1.25 MHz FFT unit 301 converts the modulated data into a fast Fourier transform (FFT). To do. Similarly, when the frequency band used for data transmission is 2.5 MHz of 2 chunks, the 2.5 MHz FFT unit 302 is selected, and when the frequency band used for data transmission is 10 MHz of 8 chunks, it is for 10 MHz. The FFT unit 304 is selected.

  Subcarrier mapping section 310 maps modulated data and null data that have been FFTed to subcarriers based on the mapping information input from scheduling section 106, and outputs the result to IFFT section 320. When the use frequency bandwidth (frequency bandwidth of the FFT unit) is smaller than the frequency bandwidth of the IFFT unit 320, the modulation data is mapped to the frequency band (chunk) used for transmission at this stage.

  IFFT section 320 performs inverse fast Fourier transform (IFFT) on the modulated data and null data that are mapped to each subcarrier and input by subcarrier mapping section 310. Here, the number of subcarriers to which the input to IFFT section 320 can be mapped varies depending on the mobile station class. For example, when the mobile station class is 10 MHz, the input to the IFFT 320 is mapped to subcarriers belonging to a frequency bandwidth of 10 MHz, whereas when the mobile station class is 5 MHz, subs belonging to the frequency bandwidth of 5 MHz. Since it is mapped to the carrier, the number of subcarriers to be mapped is half that of 10 MHz.

  An operation of selecting a chunk used for transmission in the modulation unit 103 when transmitting using one chunk as in random access will be described. In FIG. 6A, the chunk Chunk_j having the smallest frequency in the frequency band that can be handled by the IFFT unit 320 in a state where the oscillation frequency of the local oscillator in the radio unit 130 is set to a certain value as a chunk used for transmission. An example of mapping when the scheduling unit 106 designates is shown. Since the number of chunks used for transmission is one, the 1.25 MHz FFT unit 301 is selected, and the 1.25 MHz FFT unit 301 performs FFT on the modulation data generated by the AMC modulation unit 300.

  When the subcarrier mapping unit 310 receives the designation of the chunk Chunk_j as the mapping destination from the scheduling unit 106, the subcarrier mapping unit 310 maps the modulation data subjected to the FFT by the 1.25 MHz FFT unit 301 to the subcarriers belonging to the chunk Chunk_j at equal intervals. The data is output to the IFFT unit 320. That is, subcarrier mapping section 310 maps and inputs the subcarrier belonging to the chunk having the lowest frequency among the inputs to IFFT section 320. Further, subcarrier mapping section 310 maps null data for subcarriers to which FFT-modulated data is not mapped, and outputs the result to IFFT section 320. IFFT section 320 performs an IFFT on the input from subcarrier mapping section 310.

  Thereby, as shown in FIG. 6B, the output of the IFFT unit 320 becomes a spectrum of jumping at equal intervals in the 1.25 MHz frequency band (chunk Chunk_j) of the smallest frequency in the 10 MHz frequency band.

  Next, FIG. 7A shows an example of mapping when the scheduling unit 106 specifies a chunk Chunk_k whose maximum frequency is 10 MHz away from the minimum frequency of the chunk Chunk_j after transmission using the chunk Chunk_j. Show. Since the number of chunks used for transmission is one, the 1.25 MHz FFT unit 301 is selected as in the case of the chunk Chunk_j, and the 1.25 MHz FFT unit 301 receives the modulation data generated by the AMC modulation unit 300. Perform FFT.

  When the subcarrier mapping unit 310 receives the designation of the chunk Chunk_k as the mapping destination from the scheduling unit 106, the subcarrier mapping unit 310 maps the modulation data subjected to the FFT by the 1.25 MHz FFT unit 301 to the subcarriers belonging to the chunk Chunk_k at equal intervals. The data is output to the IFFT unit 320. That is, subcarrier mapping section 310 maps and inputs the subcarrier belonging to the chunk having the highest frequency among the inputs to IFFT section 320. Further, subcarrier mapping section 310 maps null data for subcarriers to which FFT-modulated data is not mapped, and outputs the result to IFFT section 320. IFFT section 320 performs an IFFT on the input from subcarrier mapping section 310.

Thereby, as shown in FIG. 7B, the output of the IFFT unit 320 becomes a spectrum of jumping at equal intervals in the 1.25 MHz frequency band (chunk Chunk_k) of the largest frequency in the 10 MHz frequency band.
As shown in FIG. 7A, the subcarrier mapping unit 310 maps the modulation data to a point group different from that in FIG. In the 1.25 MHz frequency band at a frequency position different from that shown in FIG.

  Thus, if the input of IFFT unit 320 is within the frequency band of a subcarrier that can be mapped, it is possible to change to different chunks and transmit by only switching the mapping contents by subcarrier mapping unit 310. No delay occurs when changing the oscillation frequency.

Next, the operation of modulation section 103 when transmitting using a plurality of chunks will be described.
As an example, in a mobile station apparatus having a mobile station class of 10 MHz, a case where a use frequency band is 10 MHz will be described. FIG. 8A shows an example of mapping by the subcarrier mapping unit 310 when the used frequency band is 10 MHz. As the FFT unit, the 10 MHz FFT unit 304 is selected, and the 10 MHz FFT unit 304 performs FFT on the modulated data and outputs the result. The subcarrier mapping unit 310 equally maps the output of the 10 MHz FFT unit 304 to the IFFT point of the IFFT unit 320, and further maps null data therebetween. FIG. 8B shows a spectrum example when the used frequency band is 10 MHz. As shown in FIG. 8 (b), it becomes a spectrum of jumps at equal intervals in the 10 MHz frequency band.

FIG. 9 is a schematic block diagram illustrating a configuration of the base station device BS.
The base station apparatus BS includes a transmission unit 200, a reception unit 210, and a radio unit 220. The transmission unit 200 includes a channel encoding unit 201, a data control unit 202, an OFDM modulation unit 203, and a scheduling unit 204 including a DL scheduling unit 205 and a UL scheduling unit 206. The reception unit 210 includes a demodulation unit 211, a channel estimation unit 212, a control data extraction unit 213, a channel decoding unit 214, and a reception timing deviation detection unit 215. The wireless unit 220 is shared for transmission and reception.

First, a configuration related to transmission will be described.
The channel encoding unit 201 encodes the input transmission data using the encoding rate of the AMC information input from the scheduling unit 204.

  The data control unit 202 maps the control data to the downlink common control channel DCCCH, the downlink synchronization channel DSCH, the downlink pilot channel DPICH, and the downlink shared control signaling channel DSCSCH based on an instruction from the scheduling unit 204, and each mobile station Information data for the device is mapped to the downlink shared data channel DSDCH.

  The OFDM modulation unit 203 performs OFDM signal processing such as data modulation, serial-parallel conversion of input signals, multiplication of spreading codes and scrambling codes, IFFT, GI (Gurad Interval) addition, and filtering to generate an OFDM signal. Note that the data modulation of the information data of each subcarrier is performed using the modulation scheme specified by the scheduling unit 204.

  Radio section 220 up-converts the data modulated by OFDM by OFDM modulation section 203 to a radio frequency and transmits it to mobile station apparatuses MS1 to MS4.

Next, a configuration related to reception will be described.
Radio section 220 down-converts uplink data from mobile station apparatuses MS1 to MS4 into a baseband signal, and outputs received data to demodulation section 211, channel estimation section 212, and reception timing shift detection section 215.

  Channel estimation section 212 estimates propagation path characteristics from uplink pilot channel UPICH, and outputs a propagation path characteristic estimation value to demodulation section 211. In addition, in order to perform uplink scheduling and AMC calculation of information data, the propagation path characteristic estimation result is output to the scheduling section 204.

  A reception timing deviation detection unit 215 detects a data reception timing deviation of the mobile station apparatuses MS1 to MS4 from the preamble of the uplink pilot channel UPICH or the random access channel RACH, and receives information on the reception timing deviation from the demodulation unit 211, The data is output to the data control unit 202.

  The demodulator 211 receives information about the reception timing shift input from the reception timing shift detector 215, propagation path characteristic estimation value input from the channel estimator 212, and uplink AMC information input from the control data extractor 213. The received signals transmitted from the mobile station apparatuses MS1 to MS4 are demodulated. Here, demodulating section 211 performs FFT on the received signal, separates subcarriers assigned to each mobile station apparatus based on mapping information from scheduling section 204, performs frequency equalization, and then performs IFFT. To detect single carrier demodulated data. For convenience of explanation, a case where DFT-Spread OFDM is used as an uplink communication method is described here, but other single carrier methods such as VSCRF-CDMA and multicarrier methods such as OFDM may be used. .

  The control data extraction unit 213 separates data corresponding to the uplink scheduling channel USCH section from the demodulated data detected by the demodulation unit 211 into reception data (USDCH) and control data (USCCH). The control data extraction unit 213 outputs the AMC information of the uplink reception data in the control data to the demodulation unit 211 and the channel decoding unit 214, and outputs the downlink CQI information to the scheduling unit 204.

  The AMC information of the uplink received data is basically determined and set by the base station apparatus BS from the propagation path condition estimated from the uplink pilot channels UPICH of the mobile station apparatuses MS1 to MS4, and the mobile station apparatuses MS1 to MS4. Notify The mobile station apparatuses MS1 to MS4 perform channel coding and modulation using the notified AMC information. For this reason, the base station apparatus BS stores and holds the AMC information notified to the mobile station apparatuses MS1 to MS4, and performs demodulation and channel decoding without configuring the AMC information in the uplink control data. You can also.

  Channel decoding section 214 performs channel decoding of the demodulated data based on the AMC information from control data extraction section 213, and outputs the received data to the upper layer.

  The scheduling unit 204 includes a DL scheduling unit 205 that performs downlink scheduling and a UL scheduling unit 206 that performs uplink scheduling.

  The DL scheduling unit 205 moves with respect to each downlink chunk and slot based on CQI information notified from the mobile station devices MS1 to MS4 and transmission data to each mobile station device MS1 to MS4 notified from an upper layer. The channels of the station apparatuses MS1 to MS4 are allocated, scheduling for mapping transmission data, and AMC for encoding and modulating data of each channel are calculated.

  The UL scheduling unit 206 determines each uplink chunk / slot from the estimation result of the channel characteristics of the uplink mobile station devices MS1 to MS4 from the channel estimation unit 212 and the resource allocation request from the mobile station devices MS1 to MS4. Scheduling for allocating the channel of the mobile station apparatus and calculating AMC for encoding and modulating the data of each channel.

  Note that a predetermined AMC is set in advance for the control data, the demodulator 211 demodulates the control data with a predetermined modulation scheme set in advance, and the channel decoder 214 receives the control data for Decoding is performed at a predetermined encoding rate set in advance. In FIG. 9, the channel encoding unit and the channel decoding unit for control data are not shown.

  When establishing an initial uplink connection, the mobile station apparatus performs random access on the random access channel RACH. The present invention is based on the premise that data necessary for establishing an initial connection is basically composed of a random access channel RACH in the minimum transmission frequency band. For example, in the case of a mobile station apparatus of the 1.25 MHz mobile station class whose communication capability frequency bandwidth is 1.25 MHz, the random access channel RACH at the time of initial connection establishment is basically configured at 1.25 MHz. The mobile station apparatus of the 5 MHz mobile station class can increase the connection success probability by replicating data for establishing an initial connection and performing random access using a random access channel RACH of a plurality of minimum transmission frequency bands. it can. For example, a mobile station apparatus of the 5 MHz mobile station class can simultaneously perform random access of the random access channel RACH of the four minimum transmission frequency bands.

  Here, the frequency bandwidth of the communication capability of the mobile station device is the bandwidth of the frequency band that can be communicated without changing the state of the own device, that is, the total bandwidth of all chunks that can be selected as chunks to be transmitted and received It is. The state of the own device includes settings for the own device, that is, settings for the own device such as the oscillation frequency of the local oscillator in the radio unit 130 of the mobile station device. For example, a mobile station device of a 5 MHz mobile station class whose frequency bandwidth of communication capability is 5 MHz, when transmitting a chunk having a narrower band than 5 MHz, without changing the state of the own device, the subcarrier mapping unit 310 By changing the mapping content according to, it is possible to select and transmit an arbitrary chunk from a predetermined frequency band having a bandwidth of 5 MHz.

  FIG. 10 illustrates an example of chunk selection in random access channel RACH random access. Here, as shown in FIG. 10 (1), description will be made on the assumption that the system bandwidth is 20 MHz and the frequency bandwidth for the uplink contention base channel CBCH is 5 MHz. It is not limited to. Here, in order to explain the case where the uplink is both a single carrier and a multicarrier, the frequency spectrum is not illustrated, but the chunk using the frequency band is conceptually illustrated. Note that one chunk bandwidth is 1.25 MHz.

  FIG. 10 (2) shows an example of selecting a mobile station apparatus of the 1.25 MHz mobile station class. In this example, the mobile station apparatus of the 1.25 MHz mobile station class randomly selects one chunk (chunk C8 in the figure) from the 5 MHz frequency band for the uplink contention base channel CBCH and performs random access. Random access of channel RACH is performed.

  FIG. 10 (3) shows a selection example 1 of the mobile station apparatus of the 2.5 MHz mobile station class. In this example, the mobile station apparatus of the 2.5 MHz mobile station class selects one chunk (chunk C9 in the figure) arbitrarily and performs random access on the random access channel RACH as in FIG. 10 (2).

  FIG. 10 (4) shows a selection example 2 of the mobile station apparatus of the 2.5 MHz mobile station class. In this example, the mobile station apparatus of the 2.5 MHz mobile station class arbitrarily selects two chunks (chunks C9 and C10 in the figure) from the 5 MHz frequency band for the uplink contention base channel CBCH. Random access of the random access channel RACH is performed. Although FIG. 10 (4) shows a case where adjacent chunks are selected, the present invention is not limited to such a case.

  FIG. 10 (5) shows a selection example 1 of the mobile station apparatus of the 5, 10, 15, 20 MHz mobile station class. In this example, similarly to FIGS. 10 (2) and (3), one chunk (chunk C7 in the figure) is arbitrarily selected and random access channel RACH is randomly accessed.

  FIG. 10 (6) shows a selection example 2 of the mobile station apparatus of the 5, 10, 15, 20 MHz mobile station class. In this example, similarly to FIG. 10 (4), two random chunks (chunks C7 and C8 in the figure) are arbitrarily selected to perform random access channel RACH random access.

  FIG. 10 (7) shows a selection example 3 of the mobile station apparatus of the 5, 10, 15, 20 MHz mobile station class. In this example, the random access channel RACH is randomly accessed by arbitrarily selecting three chunks (chunks C7, C8, and C9 in the figure) from the 5 MHz frequency band for the uplink contention base channel CBCH.

  FIG. 10 (8) shows a selection example 4 of the mobile station apparatus of the 5, 10, 15, 20 MHz mobile station class. In this example, all four chunks (chunks C7 to C10 in the figure) in the frequency band of 5 MHz for the uplink contention base channel CBCH are selected, and random access channel RACH is randomly accessed.

  Here, when performing random access of the random access channel RACH using a plurality of chunks, a plurality of signals for one random access channel RACH are copied and the same random access channel RACH signal is transmitted in each chunk. And a method of transmitting a signal for a random access channel RACH for a wide band using a plurality of chunks, the present invention is premised on the former method. The former can detect the mobile station apparatus by detecting the random access channel RACH of one chunk in the base station apparatus, but the latter is the random access channel of all the chunks transmitted from the specific mobile station apparatus. RACH needs to be detected.

  In addition, a broadband mobile station class mobile station apparatus, for example, a 5 MHz mobile station class mobile station apparatus, can increase the probability of successful connection by performing random access channel RACH random access using a plurality of chunks. For a mobile station device of a mobile station class in a band, for example, a mobile station device of a 1.25 MHz mobile station class, the collision probability increases. Therefore, the base station apparatus determines in advance the number of chunks that can be selected for random access of the random access channel RACH of the mobile station apparatus according to QoS (Quality of Service), the number of connected mobile station apparatuses in the cell, and the like. It is desirable that the information be broadcast to the mobile station apparatus in the cell in the downlink.

  The mobile station apparatus performs random access of the random access channel RACH by selecting the number of chunks based on the notified reference information. For example, there are many 1.25 MHz mobile station class mobile station apparatuses in a cell, and a 5 MHz mobile station class mobile station apparatus whose QoS is not so high can perform random access of the random access channel RACH using one chunk as much as possible. Do. Here, the minimum frequency bandwidth of the random access channel RACH at the time of initial connection establishment is described as 1.25 MHz, but it may be 2.5 MHz, 5 MHz, 10 MHz, etc. depending on the system configuration. For example, in a system that does not support a mobile station apparatus of 1.25 MHz mobile station class and uses a mobile station apparatus of 2.5 MHz mobile station class as the minimum mobile station class that can communicate, the minimum frequency band of the random access channel RACH The width is 2.5 MHz.

  However, it has not been proposed in detail to change a chunk at the time of retrying random access of the random access channel RACH after determining a chunk used for random access of the random access channel RACH. Each mobile station apparatus randomly selects a chunk to be used for random access channel RACH random access, but when a method that is statistically random is used, the mobile station apparatus randomly accesses a certain chunk. You may be concentrated. Random access of the random access channel RACH at the time of initial connection establishment starts transmission from the mobile station device side, and communication between the base station device and the mobile station device cannot specify the position of the chunk. Only a random method can be used.

  Therefore, the present invention efficiently distributes chunks used by the mobile station device for random access of the random access channel RACH when random access is concentrated and initial connection establishment is not successful. We propose a system that provides equal service and provides fair service. In addition, the mobile station apparatus selects the chunk candidates used for the initial random access of the random access channel RACH after narrowing down according to the unique information of the mobile station apparatus, thereby reducing the collision probability and providing a suitable service. We propose a system that provides

[First Embodiment]
In the present embodiment, the mobile station device MS1 whose mobile station class is the same as the minimum frequency bandwidth of the random access channel RACH in the system is randomized again without changing the chunk when random access of the random access channel RACH fails. Attempt random access of access channel RACH. When the mobile station class is different from the minimum frequency bandwidth of the random access channel RACH in the system and the random access channel RACH fails to access the random access channel RACH, the broadband mobile station apparatus MS2 changes the chunk and re-randomizes the random access channel RACH. Try to access.

  In FIG. 11, when random access of the first random access channel RACH fails according to different mobile station classes, the CBCH scheduling unit 105 of the mobile station apparatus performs random access channel RACH during random access retransmission of the random access channel RACH. Here is an example of changing the chunk to place. Here, the bandwidth of the minimum uplink radio resource managed by the base station apparatus BS, that is, the chunk bandwidth is 1.25 MHz, the minimum unit of the random access channel RACH is 1.25 MHz, and the mobile station apparatuses MS1 and MS2 The case where the frequency band for CBCH allocated to is 5 MHz is shown.

  In the case of a mobile station apparatus MS1 of a 1.25 MHz mobile station class (that is, a mobile station class in which the frequency bandwidth B1 of the communication capability is the same as the minimum frequency bandwidth of the random access channel RACH), the CBCH scheduling unit 105 is a random access channel. The RACH initial random access is assigned a chunk of frequency f0 (strictly speaking, a chunk of 1.25 MHz width centered on the frequency of f0, but for convenience of explanation, the above expression will be used hereafter), and the mobile station apparatus MS1 assigns this random access. The access channel RACH is transmitted (FIG. 11 (a)). When the random access of the random access channel RACH fails, that is, the control data extraction unit 113 of the mobile station apparatus MS1 sends a response from the base station apparatus BS even if a predetermined time has elapsed after transmitting the random access channel RACH. If it cannot be extracted, the CBCH scheduling unit 105 allocates a chunk of frequency f0 for re-random access of the random access channel RACH, and the mobile station apparatus MS1 transmits the random access channel RACH (FIG. 11 (b)).

  On the other hand, in the case of the mobile station device MS2 of the 5 MHz mobile station class (that is, the mobile station class whose communication capability frequency bandwidth B2 (5 MHz) is wider than the minimum frequency bandwidth (1.25 MHz) of the random access channel RACH) The CBCH scheduling unit 105 assigns a chunk of frequency f0 to the initial random access of the random access channel RACH, and the mobile station apparatus MS2 transmits the random access channel RACH (FIG. 11 (c)). When random access of this random access channel RACH fails, the CBCH scheduling unit 105 allocates a chunk of frequency f1 for re-random access of the random access channel RACH, and the mobile station apparatus MS2 transmits the random access channel RACH ( FIG. 11 (d)).

  Advantages of the above processing will be described. When the mobile station device MS1 attempts to transmit the random access channel RACH in different chunks, the frequency bandwidth of the communication capability is the same as the minimum frequency bandwidth of the random access channel RACH. The radio frequency must be switched. However, when the radio frequency of the local transmitter is switched, ON / OFF switching time and operation stabilization time of the radio unit 130 are required, and it is difficult to complete the switching of the radio frequency immediately.

  Furthermore, whether or not the random access of the random access channel RACH is successful is determined by whether or not there is a notification by the downlink control channel after the timing of transmitting the random access channel RACH. It takes time to determine whether or not. If the radio frequency is switched after the determination, there is a high possibility that the uplink contention base channel CBCH section will be over during the switching. In this case, in order to perform re-random access of the random access channel RACH, the next time It is necessary to wait until the uplink contention base channel CBCH section, and it takes time to establish the initial connection.

  A mobile station class mobile station apparatus having a wide frequency bandwidth of communication capability, for example, a mobile station apparatus MS2 of 5 MHz mobile station class, attempts to transmit the random access channel RACH in different chunks, during initial random access of the random access channel RACH. If it is within the 5 MHz band centering on the radio frequency set for the local transmitter in the radio unit 130, the modulation unit 103 can easily and quickly deal with the change of the chunk. Therefore, as compared with the mobile station apparatus MS1 of the 1.25 MHz mobile station class, the random access channel RACH can be retransmitted promptly even if the chunk is changed.

  Therefore, the mobile station apparatus MS1 transmits the random access channel RACH in the same chunk even in retransmission, and the mobile station apparatus MS2 changes the setting of the local transmitter in the radio unit 130 (the state of its own apparatus). The random access channel RACH is retransmitted while changing the chunk within the frequency bandwidth of the communication capability that may not be required. As a result, in any mobile station apparatus MS1, MS2, the random access channel is not delayed between mobile station apparatuses with different mobile station classes without causing a delay due to switching of the radio frequency until the random access channel RACH is transmitted again. The random access channel RACH can be transmitted again so that the RACH retransmissions avoid collisions.

  Further, in a mobile communication system in which two CBCH frequency bands with a system bandwidth of 20 MHz and 10 MHz are configured, a mobile station device with a mobile station class of 20 MHz does not switch radio frequencies, and either CBCH frequency Although the random access channel RACH can be transmitted in the band, a mobile station apparatus having a mobile station class of 10 MHz must switch the radio frequency in order to switch the CBCH frequency band to be used. The present invention can be applied even in such a case, and a mobile station apparatus having a mobile station class of 20 MHz changes the frequency band for CBCH when the random access channel RACH is retransmitted.

By configuring the system as described above, when random access is concentrated and initial connection establishment is not successful, the mobile station apparatus efficiently distributes chunks used for random access of the random access channel RACH, and moves It is possible to provide a fair service by equalizing the connection success probability and the collision probability between the station classes.
That is, the mobile station apparatus MS1 having the same minimum frequency bandwidth of the random access channel RACH as the predetermined frequency bandwidth and the same frequency bandwidth of the communication capability, if the random access fails, the same chunk as the failed Random access is performed again using. When the random access fails, the mobile station apparatus MS2 whose communication capability frequency bandwidth is wider than the minimum frequency bandwidth of the random access channel RACH is a different chunk from the failure, and the local oscillator oscillation frequency and the like have failed. Random access is performed again using the chunk selected from the communicable frequency band according to the setting of the local device. Accordingly, when the random access between the mobile station apparatus MS1 and the mobile station apparatus MS2 collides, each mobile station apparatus performs random access because retransmission is performed in different chunks without requiring time-consuming processing to change the setting of the own apparatus. The time until success is reduced, and random access with excellent response time can be performed.

[Second Embodiment]
In the present embodiment, in a system in which each mobile station apparatus sets a radio frequency at the center frequency of the CBCH frequency band at the time of initial random access of the random access channel RACH, when the CBCH frequency band is wideband, The chunks used for retransmission of the random access channel RACH are distributed. The mobile station apparatus of the broadband mobile station class selects a chunk that cannot be selected by a mobile station class lower than its own rank, and tries to retransmit the random access channel RACH. Here, the rank indicates the size of the mobile station class. When the mobile station class is large, the rank is high, and when the mobile station class is small, the rank is low. A chunk that cannot be selected by a mobile station class lower than the rank of the own device refers to a chunk that cannot be selected by the mobile station device of the lower mobile station class without switching the radio frequency of the local oscillator.

  First, a system for setting the oscillation frequency of the local oscillator in the radio unit 130 so that each mobile station apparatus MS1 to MS4 becomes the center frequency of the CBCH frequency band at the time of initial random access of the random access channel RACH. To do. In the present embodiment, a case where the center frequency of the system band and the center frequency of the CBCH frequency band are equal will be described.

  The mobile station apparatuses MS1 to MS4 are randomly established in the uplink for connection establishment in the idle mode in which initial connection establishment is not performed or data communication with the base station apparatus BS is not performed for a long time and connection establishment is lost. An access channel RACH is transmitted. At that time, the mobile station apparatuses MS1 to MS4 receive the downlink synchronization channel DSCH in the downlink to maintain the downlink synchronization, receive the downlink common control channel DCCCH, and receive the control information of the base station apparatus Yes. In order to avoid a decrease in frequency utilization efficiency, in this embodiment, the base station apparatus BS uses a downlink synchronization channel DSCH that is not used for data communication only for synchronization and uses a part of the system band chunk. To send. Similarly, the base station apparatus BS transmits the downlink common control channel DCCCH for transmitting the system information in the control information using a part of the chunk of the system band. Furthermore, it is necessary to determine in advance a chunk to be used for transmission so that all mobile station apparatuses before initial connection establishment can recognize and receive both channels. A chunk at the center of the system bandwidth.

  In this embodiment, the local oscillator in the radio unit 130 is also used for transmission and reception. Therefore, if the oscillation frequency of the local oscillator is set to the center frequency of the downlink system band for receiving the downlink downlink synchronization channel DSCH and the downlink common control channel DCCCH, the uplink generated by the same local oscillator The radio frequency is set to the center frequency of the uplink system band. From the above, each mobile station apparatus MS1 to MS4 is set to a radio frequency at the center frequency of the CBCH frequency band during initial random access of the random access channel RACH.

  FIG. 12 shows an example of chunk options that mobile station apparatuses MS2 to MS4 of a mobile station class of 5 MHz, 10 MHz, and 20 MHz transmit the random access channel RACH and a chunk that is selected when the random access channel RACH is retransmitted. Here, a case where the frequency bandwidth for CBCH is 20 MHz will be described. When each mobile station apparatus MS2 to MS4 in the present embodiment fails in the initial random access of the random access channel RACH, the oscillation frequency of the local oscillator is changed as a chunk that cannot be selected by a mobile station class lower than its own rank. Of the chunks that can be selected by the device itself, the random access channel RACH is retransmitted using the chunk with the highest frequency.

  As shown in FIG. 12 (a), the mobile station apparatus MS2 in the mobile station class having a communication capability frequency bandwidth B2 of 5 MHz has a frequency f (-1) to f (-1) to a choice of chunks for transmitting the random access channel RACH. Three chunks of f1. At the time of retransmission, the mobile station apparatus MS2 selects a chunk having a frequency f1, as illustrated in FIG.

  As shown in FIG. 12 (c), the mobile station apparatus MS3 of the mobile station class having a communication capability frequency bandwidth B3 of 10 MHz has a frequency range of f (−3) to f (−3). There are seven chunks of f3. At the time of retransmission, the mobile station apparatus MS3 selects a chunk having a frequency of f3 as illustrated in FIG.

As shown in FIG. 12 (e), the mobile station apparatus MS4 of the mobile station class having a communication capability frequency bandwidth B4 of 20 MHz has the frequency f (−6) to 13 chunks of f6. At the time of retransmission, the mobile station apparatus MS4 selects a chunk having a frequency of f6 as illustrated in FIG.
Thus, as the mobile station class becomes larger, the choices of chunks used at the time of random access of the random access channel RACH increase and the bandwidth is widened.

  FIG. 12 shows a case where a chunk farthest from the center frequency among the chunks that can be communicated by the mobile station apparatus is selected at the time of retransmission of the random access channel RACH. This method is a mobile station class lower than the rank of the own apparatus. Is an example of selecting a chunk that cannot be selected, and the present invention is not limited to such a case. Chunks other than the chunk farthest from the center frequency may be selected from among the chunks that cannot be selected by the mobile station class lower than the rank of the own device.

  In FIG. 13, when the initial random access of the random access channel RACH fails and the random access channel RACH is retransmitted, the chunks that the mobile station devices MS1 to MS4 of each mobile station class preferentially select by the above processing are shown. Show. As shown in FIG. 13, the mobile station device MS4 with a mobile station class of 20 MHz is a chunk of frequency band BW1 and frequency band BW7, and the mobile station device MS3 with a mobile station class of 10 MHz is a chunk of frequency band BW2 and frequency band BW6. Each mobile station apparatus MS1 has a mobile station class MS5 having a mobile station class of 5 MHz, a chunk of frequency bands BW3 and BW5, a mobile station class MS1 having a mobile station class of 1.25 MHz, and a chunk of the frequency band BW4. ~ Chunks used for random access of the random access channel RACH of MS4 are distributed.

  Furthermore, in order to improve the randomness at the time of retransmission of the random access channel RACH between mobile station apparatuses having the same mobile station class, a mobile station lower than its own rank is used by using UE_ID which is identification information unique to each mobile station apparatus. Chunk to be used is selected from the chunks that cannot be selected by the class. FIG. 14 shows an example of chunk selection at the time of retransmission of the random access channel RACH using UE_ID. In addition, although it shows about the case where UE_ID is 3 bits here, it is not limited to this. As shown in FIG. 14 (a), when the least significant bit of UE_ID is 0, the upper frequency side chunk is selected. As shown in FIG. 14 (b), when the least significant bit of UE_ID is 1, Select the side frequency side chunk. The reverse is also possible. For example, bits other than the least significant bit such as the most significant bit can be used. By the above processing, different chunks are selected according to UE_ID, so that it is possible to further improve randomness and avoid collision.

Furthermore, even when there are a plurality of chunk options for the upper frequency and the lower frequency, a chunk can be selected at random using the UE_ID. FIG. 15 shows an example of chunk selection at the time of retransmission of the random access channel RACH using UE_ID. As shown in FIG. 15, the second least significant bit of UE_ID is configured to indicate whether the upper frequency chunk or lower frequency chunk among the upper frequency chunk or lower frequency chunk from the center frequency. To do. As a result, the mobile station apparatus with the UE_ID “100” selects the chunk with the frequency f (−3) as shown in FIG. 15A, and the mobile station apparatus with the UE_ID “110” has the structure shown in FIG. As shown in FIG. 15, the mobile station apparatus having the frequency f (−2) and the UE_ID “101” selects the chunk having the frequency f2 and the UE_ID is “111” as illustrated in FIG. The mobile station apparatus selects a chunk having a frequency of f3 as shown in FIG. With the above processing, even when there are a plurality of chunks from the center frequency to the upper frequency or the lower frequency, different chunks are selected according to UE_ID, so that it is possible to further improve randomness and avoid collision.
The chunk selection method using UE_ID described above is an example, and can be extended to other methods.

  Note that the second embodiment can also be applied to a mobile station apparatus capable of transmitting and receiving a plurality of frequency bandwidths as an operation mode. That is, the capability of the radio unit 130 can be applied to a case where a mobile station apparatus capable of transmitting and receiving in a wide band is operated with a frequency bandwidth smaller than the capability. For example, in a mobile communication system of 10 MHz mobile station class, all mobile station devices are set to transmit or receive at 1.25 MHz, 2.5 MHz, 5 MHz, 10 MHz as the operation mode for each mobile station device, The station apparatus does not perform transmission or reception over a wider band than the set operation mode.

  The difference between performing transmission / reception of multiple frequency bandwidths as a mobile station class and transmission / reception of multiple frequency bandwidths as an operation mode is the necessity of switching the oscillation frequency of the local oscillator when shifting the chunk to be used How is it. For example, when the system bandwidth is 10 MHz, the oscillation frequency of the local oscillator in the radio unit 130 must be switched when shifting a chunk currently used by a mobile station device of the 1.25 MHz mobile station class. A mobile station apparatus having a 10 MHz mobile station class and an operation mode of 1.25 MHz can be realized in the processing of the modulation unit 103 when shifting a currently used chunk. The former takes time to shift the chunk, but the latter can be done immediately. The latter is assumed to be performed when the frequency band is limited due to the difference in the service system for the convenience of the mobile communication system.

  In the first embodiment, the focus is mainly on the time required for switching the oscillation frequency of the local oscillator, and in the second embodiment, attention is paid to the control to avoid a collision other than that. Yes. From the above, the second embodiment can also be applied to a system in which transmission / reception of a plurality of frequency bandwidths is defined as an operation mode as described above.

  The second embodiment can also be applied when selecting a chunk used for initial random access of the random access channel RACH. At this time, the mobile station apparatuses MS2 to MS4 select a chunk used for transmission of the random access channel RACH from among the chunks that cannot be selected by a mobile station class lower than the rank of the own apparatus, and perform initial random access.

A sequence between the mobile station apparatuses MS1 to MS4 and the base station apparatus BS when performing random access of the random access channel RACH will be described.
The mobile station apparatuses MS1 to MS4 perform PLMN (Public Land Mobile Network) selection and cell search after power-on. The base station apparatus BS periodically transmits the downlink common pilot channel DCPICH, the downlink synchronization channel DSCH, and the downlink common control channel DCCCH. The mobile station devices MS1 to MS4 select a cell to be connected from the downlink common pilot channel DCPICH and the downlink synchronization channel DSCH, and use the system bandwidth from the downlink common control channel DCCCH as broadcast information, the frequency bandwidth for CBCH, Base station apparatus information such as frequency position is acquired. After acquiring the base station apparatus information, the mobile station apparatuses MS1 to MS4 enter into the idle mode through location registration.

  The mobile station apparatuses MS1 to MS4 randomly access the base station apparatus BS using the uplink contention base channel CBCH at the time of relocation registration, initial connection for packet transmission / reception, or reconnection during packet communication. Random access of channel RACH is performed. FIG. 16 shows a flowchart of random access processing of the random access channel RACH between the mobile station apparatuses MS1 to MS4 and the base station apparatus BS.

  First, the mobile station apparatuses MS1 to MS4 select a chunk from the CBCH frequency band to attempt random access of the random access channel RACH for initial connection establishment or reconnection by an arbitrary statistically random selection algorithm. (Sa1), and the random access channel RACH is transmitted (Sa2). Here, data transmitted from the mobile station apparatuses MS1 to MS4 to the base station apparatus BS by random access of the random access channel RACH for establishing an initial connection is used to identify each mobile station apparatus called a signature in W-CDMA. Information (referred to as a signature) and information (referred to as a preamble) for synchronizing synchronization between the base station device BS and the mobile station devices MS1 to MS4 are included. Further, the mobile station apparatus may be configured to include information specific to each mobile station apparatus and information related to wireless connection, or may be transmitted to the base station apparatus BS in a later process. Here, in order to simplify the description, a case will be described in which only the preamble is transmitted by random access of the random access channel RACH for establishing the initial connection.

  When the base station apparatus BS receives the uplink contention base channel CBCH (Sa3) and detects the random access channel RACH transmitted by the mobile station apparatuses MS1 to MS4 on the uplink contention base channel CBCH (Sa4), the base station apparatus BS Performs scheduling for allocating a channel for transmitting data to mobile station apparatuses MS1 to MS4 in link scheduling channel USCH, detects a shift in reception timing between base station apparatus BS and mobile station apparatuses MS1 to MS4 from the preamble, and downlinks The signature, synchronization information, and scheduling information transmitted from the mobile station apparatuses MS1 to MS4 using the shared control signaling channel DSCSCH are transmitted to the mobile station apparatuses MS1 to MS4 in the downlink (Sa5). Alternatively, the information is transmitted on the downlink common control channel DCCCH at the head of the subsequent frames. If the base station apparatus BS does not detect the random access channel RACH from the mobile station apparatuses MS1 to MS4 even after receiving the uplink contention base channel CBCH (Sa4), the base station apparatus BS performs processing related to the random access channel RACH. Absent.

  The mobile station apparatuses MS1 to MS4 receive the downlink common control channel DCCCH or the downlink shared control signaling channel DSCSCH whose frequency band is determined in advance and monitor whether or not the signature transmitted by the own apparatus is included. When there is no data addressed to itself within the period (Sa6), as described in the first or second embodiment, a chunk for retransmitting the random access channel RACH is selected (Sa9).

  That is, in the first embodiment, the mobile station device MS1 selects the same chunk, and the mobile station devices MS2 to MS4 change the selected chunk. In the second embodiment, each mobile station apparatus MS1 to MS4 sets a radio frequency to the center frequency of the CBCH frequency band during the initial random access of the random access channel RACH. At this time, if the frequency band for CBCH is a sufficiently wide frequency band, chunks used at the time of retransmission of the random access channel RACH between the respective mobile station classes are dispersed as follows. That is, the mobile station device MS4 selects a chunk outside the frequency band of the mobile station device MS3 when this radio frequency is set, and the mobile station device MS3 selects the frequency of the mobile station device MS2 when this radio frequency is set. The mobile station apparatus MS2 selects a chunk outside the band, and the mobile station apparatus MS2 selects a chunk outside the frequency band of the mobile station apparatus MS1 at the time of setting the radio frequency. Select chunks that cannot be selected.

  Each mobile station apparatus MS1 to MS4 retries random access of the random access channel RACH with the chunk selected in step Sa9 (Sa2).

  Then, when there is a signature transmitted by the mobile station apparatus in the downlink shared control signaling channel DSCSCH (Sa6), the mobile station apparatus demodulates the downlink shared control signaling channel DSCSCH, and extracts synchronization information and scheduling information. Next, the mobile station apparatus transmits its own apparatus information such as a mobile station class and information necessary for scheduling such as QoS and data amount. The base station apparatus performs scheduling based on the own apparatus information such as the mobile station class transmitted from the mobile station apparatus and information necessary for scheduling such as QoS and data amount, and transmits the scheduling information to the mobile station apparatus. When uplink scheduling to the mobile station apparatus is performed, the mobile station apparatus starts position registration work with an upper layer and performs position registration. In location registration, temporary subscriber identity information (IMSI: International Mobile Subscriber Identity, IMSI: Temporary Mobile Identity Identity, such as TMSI (Temporary Mobile Identity), such as TMSI (Temporary Mobile Identity), for example. Are transmitted to the mobile station device together with the approval of the location registration. At the same time, a key exchange protocol and an authentication process are executed. Thus, the wireless connection process is completed (Sa7, Sa8).

This prevents random access channel RACH from colliding during retransmission between mobile station devices of different mobile station classes without changing the frequency of the local oscillator in each mobile station device, and the same mobile station class The probability that random access of the random access channel RACH may collide at the time of retransmission can be averaged between the mobile station apparatuses.
That is, each mobile station device, when random access fails, is a chunk that can be communicated according to the settings of the own device at the time of failure, and the mobile station device whose mobile station class is lower than its own device Random access is performed again using the chunk. As a result, when random access between the mobile station device MS1 and the mobile station device MS2 of different mobile station classes collides, retransmission is performed in different chunks without processing that requires time to change the setting of the own device. The time until the station apparatus succeeds in random access can be suppressed, and random access with excellent response time can be performed.
Furthermore, each mobile station apparatus collides random access between mobile station apparatuses of the same mobile station class by selecting a chunk to be used when performing random access again based on UE_ID that is identification information unique to the mobile station apparatus. Sometimes, since the probability of collision at the time of retransmission is averaged, the time until each mobile station apparatus succeeds in random access can be suppressed, and random access with excellent response time can be performed.

[Third Embodiment]
The present invention can also be applied to retrying random access of the uplink contention base channel CBCH during normal times other than the random access channel RACH.
In the present embodiment, the mobile station apparatuses MS1 to MS4 have uplink data, and when the uplink scheduling channel USCH is not allocated, or when a very small amount of data is transmitted to the base station apparatus BS, Attempt random access of the tension-based channel CBCH. Here, in the uplink contention base channel CBCH, in order to transmit an uplink request channel URCH (Uplink Request Channel) for requesting channel assignment in the uplink scheduling channel USCH, or first composed of a small amount of data This is performed to transmit an access channel FACH (Fast Access Channel).

  When transmitting the uplink request channel URCH, that is, when requesting channel allocation, the CBCH scheduling unit 105 of the mobile station apparatuses MS1 to MS4 receives the uplink request in the same manner as the random access channel RACH for initial connection establishment. A procedure for selecting a chunk to be used for random access of the channel URCH, receiving scheduling information from the base station apparatus BS, and performing data transmission using the uplink scheduling channel USCH and the mobile station apparatuses MS1 to MS4 and the base station apparatus BS To do.

  In the case of transmitting the first access channel FACH, FIG. 17 shows a flowchart of random access of the first access channel FACH (channel for transmitting a small amount of data in normal times). Also in this case, similarly to the random access channel RACH random access for establishing the initial connection, the CBCH scheduling unit 105 of the mobile station apparatuses MS1 to MS4 selects a chunk used for the random access of the fast access channel FACH (Sb1). A random access of the access channel FACH is attempted (Sb2). Here, the data transmitted on the first access channel FACH includes transmission data together with a signature and a preamble. When the base station apparatus BS detects the fast access channel FACH accompanied by transmission data randomly accessed by the mobile station apparatuses MS1 to MS4 (Sb3), the base station apparatus BS performs data processing such as data demodulation and uses the downlink shared control signaling channel DSCSCH. Then, response information such as ACK / NACK for the transmission data in the first access channel FACH is transmitted to the mobile station apparatus on the downlink (Sb4). Alternatively, the information is transmitted on the downlink common control channel DCCCH at the head of the subsequent frames. When the first access channel FACH from the mobile station devices MS1 to MS4 is not detected (Sb3), the process proceeds to the scheduling channel section without performing data processing.

  The mobile station devices MS1 to MS4 receive the downlink common control channel DCCCH or the downlink shared control signaling channel DSCSCH whose frequency band is determined in advance and monitor whether response information is included, and within a certain period of time, When there is no data addressed to the device (Sb5), the chunk for retransmitting the first access channel FACH is selected (Sb6), as described for the random access channel RACH in the first or second embodiment.

  That is, when the fast access channel FACH is retransmitted as in the first embodiment, the mobile station device MS1 whose mobile station class is the same as the minimum frequency bandwidth of the fast access channel FACH in the system selects the same chunk. The mobile station devices MS2 to MS4 whose mobile station class is wider than the minimum frequency bandwidth of the first access channel FACH in the system change the selected chunk. When retransmitting the fast access channel FACH as in the second embodiment, each mobile station apparatus MS1 to MS4 sets the radio frequency to the center frequency of the CBCH frequency band during initial access of the fast access channel FACH. . At this time, if the frequency band for CBCH is a sufficiently wide frequency band, chunks used at the time of retransmission of the fast access channel FACH between the mobile station classes are distributed as follows. That is, the mobile station device MS4 selects a chunk outside the frequency band of the mobile station device MS3 when this radio frequency is set, and the mobile station device MS3 selects the frequency of the mobile station device MS2 when this radio frequency is set. The mobile station apparatus MS2 selects a chunk outside the band, and the mobile station apparatus MS2 selects a chunk outside the frequency band of the mobile station apparatus MS1 at the time of setting the radio frequency. Select chunks that cannot be selected.

  Each mobile station apparatus MS1 to MS4 retries random access of the first access channel FACH with the chunk selected in step Sb6 (Sb2).

  Then, when there is response information addressed to the mobile station apparatus in the downlink shared control signaling channel DSCSCH (Sb5), the mobile station apparatus ends the random access processing of the first access channel FACH. When the response information is NACK, the random access of the first access channel FACH may be retried.

  Thus, not only the random access channel RACH but also all channels that perform random access on the uplink contention base channel CBCH such as the fast access channel FACH and the uplink request channel URCH are set by each mobile station device. Without random access, it prevents random access from colliding between mobile station devices of different mobile station classes, and averages the probability that random access will collide between mobile station devices of the same mobile station class during retransmission can do.

  In the first to third embodiments, it is assumed that the CBCH scheduling unit 105 determines whether or not to perform retransmission of random access depending on whether or not a response to random access returns within a certain time. However, a control unit (not shown) that receives control data and reception data from the reception unit 110, outputs transmission data, control data, and scheduling information to the transmission unit 100, and outputs control information to the radio control unit 120. Whether or not to retransmit random access may be determined based on whether or not a response to random access is returned within a certain period of time.

In the second embodiment, all mobile station apparatuses have been described as setting the local oscillator frequency at the center frequency of the CBCH frequency band during random access. However, each mobile station apparatus is determined by the mobile station class. The frequency of the local oscillator may be set to the frequency, and may not be the same frequency for all mobile station devices. In this case, if the mobile station class is the same, the frequency of the local oscillator is set to the same frequency. In a certain mobile station class, each mobile station apparatus may set the frequency of the local oscillator to one of two frequencies, for example.

  In the second embodiment, each of the mobile station apparatuses MS1 to MS4 determines the frequency band in which the mobile station class lower than the mobile station class of the own apparatus can communicate at random within the own apparatus from the time of manufacture. (For example, the CBCH scheduling unit 105) may be stored, or information transmitted from the base station apparatus BS through the downlink common control channel DCCCH as needed is stored in the own apparatus (for example, the CBCH scheduling unit 105). It may be.

  In the first to fourth embodiments, the transmission unit 100, the reception unit 110, and the radio control unit 120 in FIG. 4 and the transmission unit 200 and the reception unit 210 in FIG. 9 are realized by dedicated hardware. In addition, each unit is configured by a memory and a CPU (central processing unit), and the function is realized by loading a program for realizing the function of each unit into the memory and executing the program. Also good.

  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.

  Suitable for use in multiband wireless communication systems in which mobile phones with different communication bandwidths are mixed due to different communication standards, and these mobile phones randomly access base stations, but are not limited to this is not.

It is a schematic block diagram which shows the structure of the multiband radio | wireless communications system common to 1st to 3rd embodiment. It is a figure which shows the structural example of the flame | frame of an uplink common to 1st to 3rd embodiment. It is a figure which shows the example of arrangement | positioning of the uplink scheduling channel USCH and the uplink contention base channel CBCH to the uplink frame common to 1st to 3rd embodiment. It is a schematic block diagram which shows the structure of mobile station apparatus MS1-MS4 common to 1st to 3rd embodiment. It is a schematic block diagram which shows the structure of the modulation | alteration part 103 common to 1st to 3rd embodiment. FIG. 10 is a schematic block diagram for explaining an operation example of a modulation unit 103 when transmitting in chunk Chunk_j in the first to third embodiments. FIG. 10 is a schematic block diagram for explaining an operation example of a modulation unit 103 when transmitting in chunk Chunk_k in the first to third embodiments. FIG. 10 is a schematic block diagram illustrating an operation example of a modulation unit 103 when transmitting in chunks Chunk_j to k in the first to third embodiments. It is a schematic block diagram which shows the structure of base station apparatus BS common to 1st to 3rd embodiment. It is a figure which shows the selection example of the chunk in the random access of the random access channel RACH common to 1st to 3rd embodiment. It is a figure which shows the example of selection of the chunk used when the mobile station apparatus of each mobile station class in 1st Embodiment performs the random access of random access channel RACH. It is a figure which shows the example of selection of the chunk used when the mobile station apparatus of each mobile station class in 2nd Embodiment performs the random access of random access channel RACH. It is a figure which shows the example of the frequency band used as the selection candidate of the chunk used when the mobile station apparatus of each mobile station class in the embodiment retries random access of the random access channel RACH. It is a figure which shows the example which selects the chunk used when the mobile station apparatus of each mobile station class in the embodiment retries random access of the random access channel RACH based on the lower 1 bit of UE_ID. It is a figure which shows the example which selects the chunk used when the mobile station apparatus of each mobile station class in the embodiment retries random access of the random access channel RACH based on lower 2 bits of UE_ID. 6 is a flowchart illustrating an operation when the mobile station devices MS1 to MS4 and the base station device BS perform random access of the random access channel RACH in the embodiment. It is a flowchart explaining operation | movement at the time of the mobile station apparatus MS1-MS4 and base station apparatus BS in 3rd Embodiment performing random access of the first access channel FACH. It is a figure which shows the channel structural example of the uplink / downlink based on the proposal in 3GPP about EUTRA. It is a figure which shows the structural example of the downlink frame based on the proposal of 3GPP about EUTRA. It is a figure which shows the structural example of the uplink frame based on the proposal of 3GPP about EUTRA. It is a figure which shows the example of mapping of the uplink contention base channel CBCH and the uplink scheduling channel USCH to the uplink frame based on the proposal of 3GPP about EUTRA. It is a figure which shows the example of selection of the chunk in which the mobile station apparatuses A, B, C, D, E, and F perform random access.

Explanation of symbols

BS ... Base station apparatus MS1, MS2, MS3, MS4 ... Mobile station apparatus 100 ... Transmitting section 101 ... Channel encoding section 102 ... Data control section 103 ... Modulation section 104 ... USCH scheduling section 105 ... CBCH scheduling section 106 ... Scheduling section 107 ... Transmission timing control unit 110 ... Reception unit 111 ... OFDM demodulation unit 112 ... Channel estimation unit 113 ... Control data extraction unit 114 ... Channel decoding unit 120 ... Radio control unit 130 ... Radio unit 200 ... Transmission unit 201 ... Channel coding unit 202 ... Data control unit 203 ... OFDM modulation unit 204 ... Scheduling unit 205 ... DL scheduling unit 206 ... UL scheduling unit 210 ... Reception unit 211 ... Demodulation unit 212 ... Channel estimation unit 213 ... Control data extraction unit 214 ... Channel recovery Encoding unit 215 ... reception timing deviation detection unit 220 ... radio unit 300 ... AMC modulation unit 301 ... 1.25 MHz FFT unit 302 ... 2.5 MHz FFT unit 304 ... 10 MHz FFT unit 310 ... subcarrier mapping unit 320 ... IFFT Part

Claims (15)

In a multiband wireless communication system comprising a base station device and a mobile station device that performs random access to the base station device with a frequency bandwidth equal to or higher than a predetermined frequency bandwidth,
When the mobile station device fails in random access using one frequency band, the mobile station device again performs random access using the frequency band selected from the frequency bands that can be communicated in the state of the own device at the time of the failure. A multiband wireless communication system characterized in that: Among the mobile station apparatuses, the first mobile station apparatus in which the frequency bandwidth of the communication capability included in the own apparatus is the same as the predetermined frequency bandwidth has failed in random access using the first frequency band When the random access is performed again using the first frequency band,
Among the mobile station devices, when the second mobile station device having a frequency bandwidth of communication capability included in the own device wider than the predetermined frequency bandwidth fails in random access using the second frequency band, 2. The multiband according to claim 1, wherein random access is performed again using a frequency band that is communicable in the state of the device at the time of the failure and is different from the second frequency band. Wireless communication system. The mobile station device
When random access using one frequency band fails, it is a frequency band in which communication is possible in the state of the own device at the time of the failure, and a mobile station device whose communication capability frequency bandwidth is narrower than the own device can communicate The multiband wireless communication system according to claim 1, wherein random access is performed again using a frequency band outside a valid frequency band. The mobile station device
When starting random access, the frequency of the local oscillator of the local device is set to the frequency selected based on the frequency bandwidth of the communication capability of the local device, and the frequency band in which communication is possible in the state of the local oscillator Communication is possible when a mobile station device whose communication capability frequency bandwidth is narrower than its own device sets the local oscillator frequency of the mobile station device to a frequency selected based on the frequency bandwidth of the mobile station device's communication capability The multiband communication system according to claim 3, wherein random access is performed using a frequency band outside a specific frequency band.   The multiband radio communication system according to claim 3 or 4, wherein the mobile station apparatus uses a frequency band selected based on identification information unique to the mobile station apparatus when performing random access again. In a multiband wireless communication system comprising a base station device and a mobile station device that performs random access to the base station device with a frequency bandwidth equal to or higher than a predetermined frequency bandwidth,
The mobile station apparatus selects a frequency band used for random access based on a frequency bandwidth of communication capability of the mobile station apparatus. When starting the random access, the mobile station device sets the local oscillator frequency of the local device to a predetermined frequency and can communicate the frequency band used for the random access in the state of the local oscillator. The multiband radio communication system according to claim 6, wherein the multiband radio communication system is selected from various frequency bands.   The multiband radio communication system according to claim 6 or 7, wherein the mobile station apparatus selects a frequency band to be used when performing random access based on identification information unique to the mobile station apparatus. The multiband radio according to any one of claims 1 to 5, wherein the mobile station device selects a frequency band to be used for random access based on a frequency bandwidth of communication capability of the mobile device. Communications system. When starting the random access, the mobile station device sets the local oscillator frequency of the local device to a predetermined frequency and can communicate the frequency band used for the random access in the state of the local oscillator. The multiband radio communication system according to claim 9, wherein the multiband radio communication system is selected from various frequency bands.   The multiband radio communication system according to claim 9 or 10, wherein the mobile station apparatus selects a frequency band to be used when performing random access based on identification information unique to the mobile station apparatus. In a mobile station device that performs random access to a base station device with a frequency bandwidth greater than or equal to a predetermined frequency bandwidth,
When random access using one frequency band fails, random access is performed again using a frequency band selected from the frequency bands that can be communicated in the state of the device at the time of the failure. Mobile station device. In a mobile station device that performs random access to a base station device with a frequency bandwidth greater than or equal to a predetermined frequency bandwidth,
A mobile station apparatus, wherein a frequency band used for random access is selected based on a frequency bandwidth of a communication capability of the own apparatus. In a random access method in a multiband radio communication system comprising a base station device and a mobile station device that performs random access to the base station device with a frequency bandwidth equal to or higher than a predetermined frequency bandwidth,
When the mobile station device fails in random access using one frequency band, the mobile station device again performs random access using the frequency band selected from the frequency bands that can be communicated in the state of the own device at the time of the failure. The random access method characterized by including the 1st process to perform. In a random access method in a multiband radio communication system comprising a base station device and a mobile station device that performs random access to the base station device with a frequency bandwidth equal to or higher than a predetermined frequency bandwidth,
The mobile station apparatus includes a first step of selecting a frequency band to be used for random access based on a frequency bandwidth of the communication capability of the mobile station apparatus.

Images