JP2014222923A - Radio communications system, radio communication method, radio base station device, and mobile terminal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communications system, a radio communication method, a radio base station device, and a mobile terminal device, in which a duplex system is effectively applied, in a communication system having a frequency bandwidth configured with a plurality of basic frequency blocks.SOLUTION: A frequency bandwidth, to be allocated for communication between a radio base station device and a mobile terminal device, is configured with a first basic frequency block applying FDD system and a second basic frequency block applying TDD system or half duplex FDD system. A first downlink L1/L2 control signal corresponding to the first basic frequency block and a second downlink L1/L2 control signal corresponding to the second basic frequency block are allocated to a downlink radio resource on one of either the first or the second basic frequency block, and a downlink L1/L2 control signal, corresponding to the other basic frequency block, is frequency multiplexed in a downlink shared channel region on the one of the basic frequency blocks.

Description

  The present invention relates to a radio communication system, a radio communication method, a radio base station apparatus, and a mobile terminal apparatus in a next generation mobile communication system.

  In a UMTS (Universal Mobile Telecommunications System) network, HSDPA (High Speed Downlink Packet Access) or HSUPA (High Speed Uplink Packet Access) is adopted for the purpose of improving frequency utilization efficiency and peak data rate. A system based on CDMA (Wideband Code Division Multiple Access) is maximally extracted. For this UMTS network, Long Term Evolution (LTE) has been studied for the purpose of further improving frequency utilization efficiency and peak data rate, and reducing delay (Non-Patent Document 1). In LTE, unlike W-CDMA, as a multi-access method, a method based on OFDMA (Orthogonal Frequency Division Multiple Access) is used for the downlink (downlink), and SC-FDMA (Single Carrier) is used for the uplink (uplink). A method based on Frequency Division Multiple Access) is used.

  The third generation system (W-CMDA) can generally achieve a transmission rate of about 2 Mbps at the maximum on the downlink using a fixed band of 5 MHz. On the other hand, in the LTE system, a transmission rate of about 300 Mbps at the maximum in the downlink and about 75 Mbps in the uplink can be realized using a variable band of 1.4 MHz to 20 MHz. In addition, in the UMTS network, a successor system of LTE is also studied for the purpose of further improving the frequency utilization efficiency and the peak data rate (for example, LTE advanced or LTE enhancement (hereinafter referred to as “the LTE advanced”). LTE-A ")).

  In the LTE-A system, with the goal of further improving the frequency utilization efficiency, peak throughput, and the like, allocation of frequencies wider than LTE is being studied. In LTE-A (for example, Rel. 10), one requirement is to have backward compatibility with LTE. For this reason, a basic frequency block having a bandwidth that can be used by LTE. Adoption of a frequency band having a plurality of (Component Carrier (CC)) has been studied.

3GPP, TR25.912 (V7.1.0), "Feasibility study for Evolved UTRA and UTRAN", Sept. 2006

  By the way, as a duplex system applied to a radio communication system between a mobile station apparatus and a base station, a frequency division duplex (FDD) system and a time division duplex (TDD) are used. There is a method. The FDD scheme performs uplink communication and downlink communication at different frequencies (pair band), and the TDD scheme separates uplink and downlink by time using the same frequency for uplink communication and downlink communication.

  In the LTE system, the same radio access scheme is adopted between FDD and TDD, and maximum commonality is ensured. Therefore, in the LTE system, either the FDD method or the TDD method can be applied. On the other hand, how to set the duplex method for each basic frequency block in a system where carrier aggregation is applied in which frequency bands are added or deleted in units of basic frequency blocks and widened by multiple basic frequency blocks. Whether to perform control is an issue to be studied in the future, and a wireless communication system that effectively applies the duplex method is desired.

  The present invention has been made in view of such a point, and in a system configured by adding or deleting a frequency band in units of basic frequency blocks, a wireless communication system, a wireless communication method, and an effective application of a duplex method, An object is to provide a radio base station apparatus and a mobile terminal apparatus.

  The radio communication system of the present invention uses a first basic frequency block to which an FDD scheme is applied and a TDD scheme or a half duplex FDD scheme for a frequency band allocated to radio communication between a radio base station apparatus and a mobile terminal apparatus. A radio communication system configured to perform carrier aggregation by comprising a first fundamental frequency block and a second fundamental frequency block having a different frequency, wherein the radio base station apparatus supports the first fundamental frequency block The first downlink L1 / L2 control signal and the second downlink L1 / L2 control signal corresponding to the second fundamental frequency block are transmitted to the first fundamental frequency block or the second fundamental frequency block. The radio base station apparatus allocates to the downlink radio resource on one side, and The downlink L1 / L2 control signal corresponding to the other basic frequency block is frequency-multiplexed in the downlink shared channel region.

  According to this configuration, in order to apply different duplex systems in a communication system having a frequency band composed of a plurality of basic frequency blocks, transmission / reception of each information transmitted / received between the radio base station apparatus and the mobile terminal apparatus By controlling the duplex method applied to the information, it is possible to efficiently transmit information.

  According to the present invention, it is possible to provide a radio communication system, a radio communication method, a radio base station apparatus, and a mobile terminal apparatus to which a duplex method is effectively applied.

It is a figure which shows the hierarchical bandwidth structure agreed by LTE-A. It is a figure explaining a FDD system and a TDD system. It is a figure which shows an example of the radio | wireless communications system to which the FDD system and TDD system which concern on this Embodiment are applied. It is a figure which shows an example of the radio | wireless communications system to which the FDD system and TDD system which concern on this Embodiment are applied. It is a figure which shows an example of the radio | wireless communications system to which the FDD system and TDD system which concern on this Embodiment are applied. It is a figure which shows an example of the radio | wireless communications system to which the FDD system and TDD system which concern on this Embodiment are applied. It is a figure which shows an example of the radio | wireless communications system to which the FDD system and TDD system which concern on this Embodiment are applied. It is a figure which shows an example of the radio | wireless communications system to which the FDD system and TDD system which concern on this Embodiment are applied. It is a figure which shows an example of the radio | wireless communications system to which the FDD system and TDD system which concern on this Embodiment are applied. It is a figure which shows an example of the radio | wireless communications system to which the FDD system and TDD system which concern on this Embodiment are applied. It is a figure which shows an example of the radio | wireless communications system to which the FDD system and TDD system which concern on this Embodiment are applied. It is a figure which shows an example of the radio | wireless communications system to which the FDD system and TDD system which concern on this Embodiment are applied. It is a figure for demonstrating the structure of the mobile communication system which has the mobile terminal device and radio base station apparatus which concern on this Embodiment. It is a figure which shows schematic structure of the radio base station apparatus which concerns on embodiment of this invention. It is a figure which shows schematic structure of the mobile terminal device which concerns on embodiment of this invention.

  In a wireless communication system to which the present invention is applied, carrier aggregation is performed in which a plurality of basic frequency blocks (component carriers) are added or deleted to configure a frequency band (system band). First, a carrier aggregation system will be described with reference to FIG.

  FIG. 1 is a diagram illustrating a hierarchical bandwidth configuration agreed upon in the LTE-A system. The example shown in FIG. 1 includes an LTE-A system, which is a first mobile communication system having a first system band composed of a plurality of component carriers (CC), and a second system band composed of one component carrier. This is a hierarchical bandwidth configuration when an LTE system, which is a second mobile communication system, is present. In the LTE-A system, for example, wireless communication is performed with a variable system bandwidth of a maximum of 100 MHz, and in the LTE system, wireless communication is performed with a variable system bandwidth of a maximum of 20 MHz. The system band of the LTE-A system includes at least one component carrier that uses the system band of the LTE system as a unit, and dynamically or semi-statically adds or deletes the number of component carriers. In this way, widening the bandwidth with a plurality of component carriers is called carrier aggregation.

  For example, in FIG. 1, the system band of the LTE-A system is a system band (20 MHz × 5 = 100 MHz) including five component carrier bands, where the LTE system band (base band: 20 MHz) is one component carrier. ). In FIG. 1, mobile terminal apparatus # 1 (UE (User Equipment) # 1) is a user terminal that supports the LTE-A system (also supports the LTE system) and can support a system band up to 100 MHz. UE # 2 is a user terminal that supports the LTE-A system (also supports the LTE system), and can support a system band up to 40 MHz (20 MHz × 2 = 40 MHz). UE # 3 is a user terminal compatible with the LTE system (not compatible with the LTE-A system), and can support a system band up to 20 MHz (base band).

  Further, as described above, there are an FDD scheme and a TDD scheme as a duplex scheme applied to a radio communication system between a mobile station apparatus and a radio base station apparatus (see FIG. 2). For example, when the FDD scheme is applied in the LTE system, it is conceivable to apply the FDD scheme in each fundamental frequency block (CC) also in LTE-A from the viewpoint of backward compatibility. However, in the LTE-A system, it is necessary to expand the frequency bandwidth in order to realize high-speed transmission, and there is a problem that it is difficult to secure an upstream and downstream pair band in FDD. In addition, in the TDD scheme, a period during which transmission is possible for both uplink and downlink is limited, so that there is a problem that transmission delay increases and coverage decreases. For this reason, when the same method is applied to all CCs, there is a possibility that a problem occurs in communication.

  On the other hand, in the FDD scheme, different frequency bands are assigned to uplink and downlink, and transmission is always possible in uplink and downlink (uplink and downlink in all transmission time intervals (TTI) (subframe in LTE)). Since it is possible to assign various information such as data and control information to downlink radio resources), there is an advantage that transmission delay can be suppressed and transmission / reception timing of various information can be set flexibly. In addition, since the TDD scheme has the same uplink and downlink frequency bands, the transmission and reception lines have the same propagation characteristics including instantaneous fluctuations in uplink and downlink fading. Therefore, by applying the weighting coefficient (channel coefficient) used in reception to the weighting in transmission as it is (Channel reciprocity (channel reversibility)), feedback of channel state information from the receiving unit can be reduced. Has advantages.

  Therefore, the present inventor has conceived that in a carrier aggregation system in which a wide band is formed by a plurality of basic frequency blocks, the FDD method and the TDD method (or the Half duplex FDD method) are combined and applied to different basic frequency blocks. It came. In addition, in a carrier aggregation system that expands the bandwidth with a plurality of component carriers, when different duplex systems are applied, control system information (control information) and data system information (data information) necessary for communication control are used. ) Was set in consideration of the duplex method, and the transmission of information was conceived to arrive at the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, an example in which the present invention is applied to LTE-A will be described, but the present invention is not limited to the case where it is applied to LTE-A. The present invention may be applied to any radio communication system as long as it is a radio communication system that applies different duplex schemes in carrier aggregation in which a plurality of fundamental frequency blocks are integrated into a wide band.

  Moreover, in the following description, although the case where the number of fundamental frequency blocks (CC) is two is demonstrated, this invention is not limited to this, Even if the number of CC is more than two, The FDD method and the TDD method can be applied in appropriate combination.

<Wireless communication system composed of FDD / TDD>
The radio communication system shown in the present embodiment is a radio communication system configured by adding or deleting a frequency band allocated to radio communication between a radio base station apparatus and a user terminal (mobile terminal apparatus) in units of basic frequency blocks. When the frequency band is composed of a plurality of basic frequency blocks, the frequency band is at least a first basic frequency block that performs FDD wireless communication and a second basic frequency block that performs TDD wireless communication. Configure (see FIG. 3).

  FIG. 3 shows a case where FDD wireless communication is performed in the first basic frequency block (CC # 1) and TDD wireless communication is performed in the second basic frequency block (CC # 2). In CC # 1 to which the FDD scheme is applied, uplink communication and downlink communication are performed at different frequencies (pair bands), and in CC # 2 to which the TDD scheme is applied, uplink communication and downlink communication have the same frequency. Separated by time.

  In CC # 1, different frequency bands are assigned to uplink and downlink, and transmission is always possible in uplink and downlink, so transmission delay can be suppressed and various information transmission / reception timings can be set flexibly. . On the other hand, in CC # 2, since the uplink and downlink frequency bands are the same, wireless communication using Channel reciprocity can be performed.

  Therefore, for each CC, control information and data for controlling the radio communication between the radio base station apparatus and the mobile terminal apparatus based on the advantages of the two duplex systems and the backward compatibility viewpoint with the LTE system. By controlling the allocation of various information such as the information, it becomes possible to efficiently transmit information. The control information includes a synchronization channel signal, a PBCH signal, a PRACH signal, a downlink L1 / L2 control channel signal, an uplink L1 / L2 control channel signal, and the like.

  Hereinafter, when different duplex systems are applied to a plurality of fundamental frequency blocks, a method for assigning various information (channel signal, reference signal, etc.) to each fundamental frequency block will be specifically described.

<Synchronization channel, PBCH, PRACH>
FIG. 4 illustrates a wireless communication system including a first basic frequency block (CC # 1) to which the FDD scheme is applied and a second basic frequency block (CC # 2) to which the TDD scheme is applied. An example of the setting of various information related to the initial access of the mobile terminal device to the station device is shown.

  Examples of channels related to the initial access of the mobile terminal device to the radio base station device include a synchronization channel (SS), PBCH (Physical Broadcast Channel), and PRACH (Physical Random Access Channel).

  The synchronization channel is used for cell search for detecting a base station apparatus to which a mobile terminal apparatus is to be connected. Since the mobile terminal device does not know the frequency bandwidth of the cell to be connected at the time of cell search, the center frequency (for example, 72 subcarriers (actually 63 subcarriers of these) is used regardless of the system frequency bandwidth). ). Also, the synchronization channel is configured to multiplex and transmit the first subframe # 1 and the sixth subframe # 6 in a 10 ms radio frame (first subframe # 1 to tenth subframe # 10) with a period of 5 ms. It can be.

  The PBCH is a common control channel that broadcasts system-specific and cell-specific control information to the entire cell, and is a physical channel that is received next by a mobile terminal device that has completed a normal cell search. Since the frequency bandwidth of the cell to be connected is unknown, the mobile terminal device after the cell search is completed, the PBCH is assigned to the center frequency (for example, 72) regardless of the frequency bandwidth of the system, similarly to the synchronization channel. Subcarrier (6RB)) is used for transmission. Also, the PBCH signal can be multiplexed in four OFDM symbols from the beginning of the second slot of the first subframe # 1 and transmitted at a cycle of 40 ms.

  The PRACH is transmitted from the mobile terminal device at the start of communication, establishes synchronization between the uplink mobile terminal devices, and becomes a physical channel for an initial accelerator for performing settings for starting communication. The PRACH signal is transmitted using a predetermined subframe (transmission bandwidth is 72 subcarriers) indicated by the radio base station apparatus.

  In the present embodiment, transmission / reception of information regarding these initial accesses is performed by using the first fundamental frequency block (CC # 1) to which the FDD scheme is applied or the second fundamental frequency block (CC # 2) to which the TDD scheme is applied. ) Is used.

  In FIG. 4, information is transmitted by allocating the synchronization channel and PBCH to downlink radio resources of CC # 1 to which the FDD scheme is applied (for example, 72 subcarriers at the center frequency of the used frequency band), and the PRACH is FDD Is assigned to the uplink radio resource of CC # 1 to which is applied. That is, the synchronization channel, PBCH, and PRACH are allocated to the pair band of the first basic frequency block to which the FDD scheme is applied, and information is transmitted.

  On the other hand, when the TDD scheme is the center, the synchronization channel and the PBCH are allocated to the downlink radio resource of CC # 2 to which the TDD scheme is applied (for example, 72 subcarriers at the center frequency of the used frequency band) and information is transmitted. Then, the PRACH may be allocated to the uplink radio resource of CC # 2 to which the TDD scheme is applied, and information may be transmitted.

<Downlink L1 / L2 control signal>
FIG. 5 illustrates a downlink in a wireless communication system including a first basic frequency block (CC # 1) to which the FDD scheme is applied and a second basic frequency block (CC # 2) to which the TDD scheme is applied. An example of transmission of an L1 / L2 control signal is shown.

  The downlink L1 / L2 control signal is a signal for control between layer 1 and layer 2, and each mobile terminal device has RB allocation information in PDSCH, data modulation scheme / channel coding rate, retransmission related information, etc. It consists of control information. Also, transmission of the downlink L1 / L2 control signal is controlled using channels of PCFICH (Physical Control Format Indicator Channel), PDCCH (Physical Downlink Control Channel), and PHICH (Physical Hybrid-ARQ Indicator Channel).

  PDCCH is a control channel indicating scheduling information of PDSCH (Physical Downlink Shared Channel) and PUSCH (Physical Uplink Shared Channel) and format information such as modulation method and channel coding rate, and is allocated to downlink radio resources.

  PCFICH is a physical channel used for reporting the number of radio resources used for all PDCCH transmissions in each subframe in units of the number of OFDM symbols, and the head of each subframe (up to 3 OFDM symbols) in the downlink Assigned to

  The PHICH is a control channel that transmits ACK / NACK (Acknowledgement / Negative Acknowledgement) of HARQ (Hybrid Automatic Repeat Request) for PUSCH, and is allocated to the head of each subframe in the downlink.

  In the present embodiment, the downlink L1 / L2 control signal corresponding to the first basic frequency block (CC # 1) and the downlink L1 / L2 control signal corresponding to the second basic frequency block (CC # 2) are received. , And collectively allocated to downlink radio resources of CC # 1 to which the FDD scheme is applied or CC # 2 to which the TDD scheme is applied.

  FIG. 5 shows a case in which PDCCH corresponding to CC # 1 and PDCCH corresponding to CC # 2 are aggregated and allocated to downlink radio resources of CC # 1 and information is transmitted. In this case, the PDCCH corresponding to CC # 2 may be allocated and transmitted in the area of the first symbol of one frame in the same way as the PDCCH corresponding to CC # 1, or as shown in FIG. May be frequency-multiplexed in an area to which information is allocated. In this way, the PDCCH corresponding to CC # 2 is aggregated and allocated to the downlink radio resources of CC # 1, and transmitted, so that the control information corresponding to CC # 2 to which the TDD scheme is applied can be uplinked and downlinked. Therefore, it is possible to set transmission / reception timing of various information flexibly while suppressing transmission delay.

  On the other hand, when the TDD scheme is the center, PDCCH corresponding to CC # 1 and PDCCH corresponding to CC # 2 may be aggregated and allocated to downlink radio resources of CC # 2 to transmit information. . In this case, in CC # 2 to which the TDD scheme is applied, compared to CC # 1 to which the FDD scheme is applied, there is less downlink TTI in the time direction. It is preferable to aggregate and assign PDCCHs for a plurality of TTIs and transmit information (see FIG. 6).

<Uplink L1 / L2 control signal>
In FIG. 7, in a radio communication system including a first fundamental frequency block (CC # 1) to which the FDD scheme is applied and a second fundamental frequency block (CC # 2) to which the TDD scheme is applied, An example of transmission of an L1 / L2 control signal is shown.

  The uplink L1 / L2 control signal is a signal for controlling between layer 1 and layer 2, and reports channel quality information (CQI: Channel Quality Indicator) for downlink frequency scheduling, ACK / NACK for downlink transmission data, It consists of control information such as a scheduling request for indicating that the mobile terminal apparatus needs uplink resources for data transmission.

  A control signal transmitted on the uplink is time-multiplexed with PUSCH when transmitting simultaneously with user data, and assigned to an uplink control channel (PUCCH: Physical Uplink Control Channel) when transmitting only the control signal. .

  The PUCCH is used to transmit reception channel quality information measured by the mobile terminal apparatus and downlink PDSCH delivery confirmation information. The subframe configuration includes seven SC-FDMA symbols in one slot (1/2 subframe), and a data signal and a reference signal are time-multiplexed to suppress an increase in peak power. Also, both the reception channel quality information (CQI) measured by the mobile terminal apparatus and the downlink PDSCH delivery confirmation information (ACK / NACK) are transmitted in the 12 subcarrier band. Specifically, different subframe configurations are used when CQI and ACK / NACK are transmitted, and the subframe configuration (ACK / NACK format) of ACK / NACK is the third symbol to the fifth symbol in the slot. RS is multiplexed, and control information (ACK / NACK) is multiplexed on other symbols (first symbol, second symbol, sixth symbol, seventh symbol). The slot is repeated twice in one subframe. The PUCCH is multiplexed on radio resources at both ends of the system band, and frequency hopping (Inter-slot FH) is applied between two slots having different frequency bands in one subframe.

  In the present embodiment, an uplink L1 / L2 control signal corresponding to the first basic frequency block (CC # 1) and an uplink L1 / L2 control signal corresponding to the second basic frequency block (CC # 2) are received. , And collectively allocated to uplink radio resources of either CC # 1 to which the FDD scheme is applied or CC # 2 to which the TDD scheme is applied.

  FIG. 7 illustrates a case where information is transmitted by collecting and assigning PUCCH corresponding to CC # 1 and PUCCH corresponding to CC # 2 to uplink radio resources of CC # 1. Specifically, an uplink control signal corresponding to CC # 2 is allocated to the PUCCH of CC # 1, and information is transmitted.

  In the second basic frequency block to which the TDD scheme is applied, the uplink and downlink are separated by time, and therefore, in the subframe period corresponding to the uplink of the TDD scheme ("UL period" in the figure) May not be sent. That is, in the uplink PUCCH of CC # 1, an uplink control signal corresponding to CC # 1 and CC # 2 may be assigned, or only an uplink control signal of CC # 1 may be assigned. In this case, in the uplink PDCCH of CC # 1, the bit information is different when an uplink control signal corresponding to CC # 1 and CC # 2 is assigned and when only an uplink control signal of CC # 1 is assigned. Therefore, PUCCH formats with different spreading factors and signal configurations may be applied in each case.

  Also, when the control signal transmitted in the uplink is transmitted simultaneously with the user data, the PUCCH corresponding to CC # 1 and the PUCCH corresponding to CC # 2 are changed to the PUSCH of CC # 1 and / or CC # 2. Can be multiplexed and transmitted. When it is necessary to limit the number of CCs for transmitting control signals to one, PUCCH corresponding to CC # 1 and PUCCH corresponding to CC # 2 are aggregated into PUSCH of CC # 1 or CC # 2 (time multiplexing) It is preferable to transmit.

  On the other hand, when the TDD scheme is mainly used, the PUCCH corresponding to CC # 1 and the PUCCH corresponding to CC # 2 may be aggregated and allocated to uplink radio resources of CC # 2. In this case, in CC # 2 to which the TDD scheme is applied, compared to CC # 1 to which the FDD scheme is applied, there is less uplink TTI in the time direction. Thus, it is preferable that PUCCHs corresponding to a plurality of TTIs are aggregated, allocated and transmitted (see FIG. 8).

<Shared data channel>
In FIG. 9, in a wireless communication system configured with a first fundamental frequency block (CC # 1) to which the FDD scheme is applied and a second fundamental frequency block (CC # 2) to which the TDD scheme is applied, shared data An example of transmission of a channel (PDSCH, PUSCH) signal is shown.

  As shared data channel signals, in addition to data traffic that requires a high data rate, priority is given to ensuring coverage over transmission speed itself such as broadcast information (SI: System Information), voice data (VoIP: Voice over IP), etc. There is something to be done.

  Broadcast information used in the LTE system is classified into MIB (Master Information Block) transmitted using PBCH and SIB (System Information Block) transmitted using PDSCH. In this case, the MIB includes information necessary for receiving the downlink (downlink bandwidth, downlink control channel configuration, etc.). On the other hand, SIBs are classified from SIB1 to SIBx, and SIB1 includes subsequent SIB scheduling information, and SIB2 and subsequent system information such as broadcast information for each cell. The change of the system information is recognized by the mobile terminal device by the tag information (System Info Value Tag) and the PCH (Paging Channel) flag included in the SIB1.

  Further, in order to realize voice data (VoIP), application of semi-persistent scheduling (SPS) is being studied. With respect to the downlink, the SPS uses the subframe (allocation start point) in which the radio base station apparatus transmits the downlink scheduling information to the mobile terminal apparatus via the PDCCH as a starting point, and the downlink radio resource (PDSCH) It is configured to be fixedly assigned to the mobile station at a predetermined period. For the uplink, the radio base station apparatus starts from the subframe (allocation start time) 4 ms after the subframe in which the uplink scheduling grant is transmitted to the user apparatus via the PDCCH. (PUSCH) is fixedly assigned to the user apparatus at a predetermined period.

  In the present embodiment, the shared data channel signal is either the first basic frequency block (CC # 1) to which the FDD scheme is applied or the second basic frequency block (CC # 2) to which the TDD scheme is applied. To do.

  In FIG. 9, broadcast information to be transmitted using the PDSCH is allocated to a downlink radio resource of CC # 1 to which the FDD scheme is applied (using the PDSCH of CC # 1) and transmitted. Thereby, the effect that a coverage is securable can be show | played.

  Also, VoIP is allocated to uplink and downlink radio resources of CC # 1 to which the FDD scheme is applied (using PDSCH and PUSCH of CC # 1), and semi-persistent scheduling is applied. That is, VoIP is performed using a pair band of the first basic frequency block to which the FDD scheme is applied. In this case, an effect that the coverage can be ensured can be achieved.

  On the other hand, when centering on the TDD scheme, broadcast information is allocated to a downlink radio resource of CC # 2 to which the TDD scheme is applied (using PDSCH of CC # 2) and VoIP is applied to the TDD scheme. May be allocated to uplink and downlink radio resources of CC # 2 (using PDSCH and PUSCH of CC # 2).

  Also, different scrambling may be applied to CC # 1 to which the FDD scheme is applied and CC # 2 to which the TDD scheme is applied. For example, Cell-specific scrambling can be applied to CC # 1, and UE-specific scrambling can be applied to CC # 2.

<Downlink reference signal>
In FIG. 10, in a radio communication system configured with a first fundamental frequency block (CC # 1) to which the FDD scheme is applied and a second fundamental frequency block (CC # 2) to which the TDD scheme is applied, the downlink An example of reference signal transmission is shown.

  Examples of the downlink reference signal include a common reference signal (CRS), a reference signal for demodulation (DM RS: Demodulation Reference Signal), a CSI-RS (Channel State Information Reference Signal), and the like.

  CRS is used for demodulation of transmission data, downlink channel quality (CQI) measurement for scheduling and adaptive control, and measurement of average channel state of downlink for cell search and handover ( Used for mobility measurement).

  In the downlink of the LTE advanced system (LTE-A system), CSI-RS is defined exclusively for CQI measurement in addition to CRS. CSI-RS corresponds to CQI measurement of a plurality of cells in consideration of transmission / reception of a data channel signal by CoMP (Coordinated multiple point). CSI-RS is different from CRS used for CQI measurement of only a serving cell in that it is used for CQI measurement of a neighboring cell.

  In the present embodiment, CRS is allocated to the downlink radio resource of the first basic frequency block (CC # 1), and CSI-RS is allocated to the downlink radio resource of the second basic frequency block (CC # 2). It can be assigned and transmitted. In this case, in CC # 2 uplink to which the TDD scheme is applied, adaptive transmission using channel reciprocity may be performed based on the received CSI-RS.

  Also, a part of CRS may be allocated to the downlink radio resource of CC # 2, or a configuration may be adopted in which the CRS is not completely allocated. Also, the DM-RS can be configured to be allocated to the downlink radio resources of both CC # 1 and CC # 2 and transmitted.

  In addition, the CRS may be allocated to the downlink radio resource of CC # 2, and the CSI-RS may be allocated to the downlink radio resource of CC # 1 to perform transmission.

<Uplink reference signal>
In FIG. 11, in a radio communication system configured with a first fundamental frequency block (CC # 1) to which the FDD scheme is applied and a second fundamental frequency block (CC # 2) to which the TDD scheme is applied, An example of reference signal transmission is shown.

  As reference signals in the uplink, demodulation reference signals (DM RS: Demodulation Reference Signal) for physical uplink shared channel and uplink control channel and sounding reference signal (SRS) are used.

  In Release 8 LTE, SRS is multiplexed with the last symbol of a subframe constituting an uplink radio frame and periodically transmitted from the mobile terminal apparatus to the radio base station apparatus. The radio base station apparatus measures uplink channel quality based on SRS for channel quality measurement transmitted from the mobile terminal apparatus, performs scheduling for the mobile terminal apparatus to transmit a data channel signal (PUSCH), Instruct using PDCCH.

  In the present embodiment, the SRS is allocated to the uplink radio resource of the first basic frequency block (CC # 1) and the uplink radio resource of the second basic frequency block (CC # 2), respectively. In this case, the SRS assigned to CC # 1 and CC # 2 can be controlled independently. For example, in CC # 1, the SRS transmission cycle can be set shorter than CC # 2. Further, in CC # 2 downlink to which the TDD scheme is applied, adaptive transmission using channel reciprocity may be performed based on the received SRS. Thereby, the overhead of SRS transmission can be reduced.

  Also, the DM-RS can be configured to be allocated to the downlink radio resources of both CC # 1 and CC # 2 and transmitted.

<Radio communication system composed of FDD system / Half duplex FDD system>
In FIG. 3 to FIG. 11 described above, wireless communication configured by the first basic frequency block (CC # 1) to which the FDD scheme is applied and the second basic frequency block (CC # 2) to which the TDD scheme is applied. Although the system has been described, the present invention is not limited to this. As shown in FIG. 12, a Half duplex FDD (half duplex FDD) method may be applied instead of the TDD method. Specifically, FIG. 12 shows a radio composed of a first basic frequency block (CC # 1) to which the FDD scheme is applied and a second basic frequency block (CC # 2) to which the Half duplex FDD scheme is applied. 1 shows a communication system.

  The Half duplex FDD scheme is a communication scheme in which different frequency bands are set for uplink and downlink as in the FDD scheme, while the transmission side and the reception side perform data transmission alternately. That is, information is not allocated to uplink and downlink radio resources at the same time, and uplink and downlink are separated not only by frequency but also by time. When the Half duplex FDD scheme is applied, the uplink and downlink signals can be easily separated, and the configuration of the mobile terminal apparatus can be simplified.

  Allocation of channels and signals is also applied to a radio communication system including a first fundamental frequency block (CC # 1) to which the FDD scheme is applied and a second fundamental frequency block (CC # 2) to which the TDD scheme is applied. As the method, the methods shown in FIGS. 4 to 11 can be similarly applied. Specifically, in the method shown in FIG. 4 to FIG. 11, the TDD system can be replaced with the Half duplex FDD system.

<System configuration diagram>
Hereinafter, configurations of a mobile terminal apparatus, a radio base station apparatus, and the like to which the above-described radio communication system is applied will be described. Here, a case where a radio base station apparatus and a mobile terminal apparatus having a plurality of antennas corresponding to the LTE-A system are used will be described.

  First, a radio communication system 1 having a mobile terminal device 200 and a radio base station device 100 will be described with reference to FIG. FIG. 13 is a diagram for explaining a configuration of a radio communication system 10 including mobile terminal apparatus 200 and radio base station apparatus 100 according to an embodiment of the present invention. Note that the radio communication system 10 illustrated in FIG. 13 is a system including an LTE system, for example.

As illustrated in FIG. 13, the radio communication system 10 includes a radio base station apparatus 100 and a plurality of mobile terminal apparatuses 200 (200 ₁ , 200 ₂ , 200 ₃ ,... 200 _n that communicate with the radio base station apparatus 100. , N is an integer of n> 0). Radio base station apparatus 100 is connected to core network 40. The mobile terminal apparatus 200 communicates with the radio base station apparatus 100 in the cell 50. The core network 40 includes, for example, an access gateway device, a radio network controller (RNC), a mobility management entity (MME), and the like, but is not limited thereto.

  In the radio communication system 10, OFDMA is applied to the downlink and SC-FDMA is applied to the uplink as the radio access scheme.

  OFDMA is a multi-carrier transmission scheme that performs communication by dividing a frequency band into a plurality of narrow frequency bands (subcarriers) and mapping data to each subcarrier. SC-FDMA is a single carrier transmission method in which data is mapped to a continuous band for each terminal for communication, and a plurality of terminals use different bands to realize multi-access.

  Here, a communication channel in the LTE system will be described. For downlink, PDSCH for transmitting traffic data of each mobile terminal apparatus 200, and L1 / L2 control such as RB allocation information in PDSCH, data modulation scheme / channel coding rate, retransmission related information to each mobile terminal apparatus 200 PDCCH or the like for notifying information is used. Further, reference signals used for channel estimation, reception quality measurement and the like are transmitted together with these channels.

  For uplink, PUSCH for transmitting traffic data of each mobile terminal apparatus 200, channel quality information (CQI) report for downlink frequency scheduling, and L1 / L2 control information such as ACK / NACK for downlink transmission data are transmitted. PUCCH or the like is used. Also, a demodulation reference signal used for channel estimation and a channel quality measurement reference signal used for channel quality measurement are transmitted together with these channels.

  Next, an example of a functional configuration of the radio base station apparatus configuring the above-described radio communication system will be described with reference to FIG.

  The radio base station apparatus shown in FIG. 14 includes a transmission unit and a reception unit. The transmission unit includes a synchronization channel generation unit 101, a broadcast channel generation unit 102, a downlink L1 / L2 control channel generation unit 103, a downlink shared channel generation unit 104, and a resource mapping unit that assigns each signal to a radio resource 111 to 114, IFFT units 121 and 122 for performing inverse fast Fourier transform on the mapped information, CP adding units 131 and 132 for adding a CP, and a first transmission circuit unit 141 for transmitting information to apply the FDD scheme And a second transmission circuit unit 142 that transmits information to which the TDD method is applied.

  The synchronization channel generation unit 101 generates a synchronization channel signal to be allocated to downlink radio resources. Broadcast channel generation section 102 generates a broadcast channel (PBCH or the like) to be allocated to downlink radio resources. The downlink L1 / L2 control channel generation unit 103 generates a signal (PDCCH signal or the like) to be transmitted using the downlink L1 / L2 control channel. The downlink shared channel generation unit 104 generates information (such as VoIP) to be allocated to downlink radio resources.

  The resource mapping units 111 to 114 allocate radio signals to signals generated by the synchronization channel generation unit 101, the broadcast channel generation unit 102, the downlink L1 / L2 control channel generation unit 103, and the downlink shared channel generation unit 104. . Specifically, each signal is mapped to a first fundamental frequency block to which the FDD scheme is applied and a second fundamental frequency block to which the TDD scheme is applied. Here, a case is shown in which control information necessary for communication control is assigned to the first fundamental frequency block, and other data information is assigned to the second fundamental frequency block. The assignment shown in FIG. 11 can be applied. In FIG. 14, the reference signal is not shown, but the generated reference signal can also be assigned to any of the basic frequency blocks using the resource mapping unit.

  The receiving unit includes a first receiving circuit unit 191 that receives information applying the FDD scheme, a second receiving circuit unit 192 that receives information applying the TDD scheme, and CP removing units 181 and 182 that remove CP. FFT units 171 and 172 that perform fast Fourier transform (FFT) on the received signal, resource demapping units 161 to 163 that separate the multiplexed signals, an uplink shared channel receiver 151 that receives the uplink shared channel signal, An uplink L1 / L2 control channel signal reception unit 152 that receives an uplink L1 / L2 control channel signal and a random access channel detection unit 153 that detects a random access channel are included.

  The scheduler unit 110 controls resource allocation for each basic frequency block. In addition, scheduling is performed by distinguishing LTE terminal users and LTE-A terminal users. In addition, the scheduler unit 110 receives transmission data and a retransmission instruction from the upper station apparatus, and receives a channel estimation value and a CQI of a resource block from a receiving unit that measures an uplink signal. The scheduler unit 110 performs scheduling of the up / down control signal and the up / down shared channel signal while referring to the retransmission instruction, the channel estimation value, and the CQI input from the higher station apparatus. The propagation path in mobile communication varies depending on the frequency due to frequency selective fading. Therefore, adaptive frequency scheduling for assigning resource blocks with good communication quality for each subframe to each mobile terminal device when user data is transmitted to the mobile terminal device is applied. In adaptive frequency scheduling, a user terminal with good channel quality is selected and assigned to each resource block. Therefore, scheduler section 110 allocates resource blocks using CQI for each resource block fed back from each mobile terminal apparatus. Further, an MCS (coding rate, modulation scheme) that satisfies a predetermined block error rate with the allocated resource block may be determined. For the second fundamental frequency block to which the TDD scheme is applied, the weighting coefficient (channel coefficient) used in reception is applied to the weighting in transmission as it is (Channel reciprocity) to control the transmission / reception of information. It is preferable.

  Next, with reference to FIG. 15, an example of a functional configuration of the mobile terminal apparatus constituting the above-described wireless communication system will be described.

  The mobile terminal apparatus shown in FIG. 15 includes a transmission unit and a reception unit. The transmission unit includes an uplink shared channel generation unit 201, an uplink L1 / L2 control channel generation unit 202, a random access channel generation unit 203, resource mapping units 211 to 213 that allocate radio signals to each signal, mapping IFFT units 221 and 222 that perform inverse fast Fourier transform on the received information, CP addition units 231 and 232 that add CP, a first transmission circuit unit 241 that transmits information to which an FDD scheme is applied, and a TDD scheme are applied And a second transmission circuit unit 242 for transmitting information to be transmitted.

  The uplink shared channel generation unit 201 generates a signal (PUSCH signal) to be transmitted using an uplink shared channel with uplink radio resources. Uplink L1 / L2 control channel generation section 202 generates a signal (such as a PUCCH signal) to be transmitted using the uplink L1 / L2 control channel. The random access channel generation unit 203 generates a signal (PLACH signal) to be transmitted using a random access channel with uplink radio resources.

  The resource mapping units 211 to 213 allocate radio signals to the signals generated by the uplink shared channel generation unit 201, the uplink L1 / L2 control channel generation unit 202, and the random access channel generation unit 203. Specifically, each signal is mapped to a first fundamental frequency block to which the FDD scheme is applied and a second fundamental frequency block to which the TDD scheme is applied. Here, a case is shown in which control information necessary for communication control is assigned to the first fundamental frequency block, and other data information is assigned to the second fundamental frequency block. The assignment shown in FIG. 11 can be applied. In FIG. 14, the reference signal is not shown, but the generated reference signal can also be assigned to any of the basic frequency blocks using the resource mapping unit.

  The receiving unit includes a first receiving circuit unit 291 that receives information to apply the FDD method, a second receiving circuit unit 292 that receives information to apply the TDD method, and CP removing units 281 and 282 that remove CP. FFT units 271 and 272 that perform fast Fourier transform (FFT) on the received signal, resource demapping units 261 to 264 that separate the multiplexed signals, synchronization channel detection unit 251, broadcast channel reception unit 252, downlink channel An L1 / L2 control channel receiving unit 253 and a downlink shared channel receiving unit 254 are provided.

  In addition, unless it deviates from the scope of the present invention, the number of processing units and the processing procedure in the above description can be appropriately changed and implemented. Each element shown in the figure represents a function, and each functional block may be realized by hardware or software. Other modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Radio | wireless communications system 40 Core network 50 Cell 100 Radio base station apparatus 101 Synchronization channel production | generation part 102 Broadcast channel production | generation part 103 Downlink L1 / L2 control channel production | generation part 104 Downlink shared channel production | generation part 110 Scheduler part 111-114 Resource mapping part 121, 122 IFFT units 131 and 132 CP adding unit 141 first transmission circuit unit 142 second transmission circuit unit 151 uplink shared channel reception unit 152 uplink L1 / L2 control channel signal reception unit 153 random access channel detection unit 161 to 163 Mapping unit 171, 172 FFT unit 181, 182 CP removing unit 191 First receiving circuit 192 Second receiving circuit 200 Mobile terminal apparatus 201 Uplink shared channel generating unit 202 Uplink L1 / L2 control channel Generation unit 203 Random access channel generation unit 211 to 213 Resource mapping unit 222, 223 IFFT unit 231, 232 CP addition unit 241 First transmission circuit unit 242 Second transmission circuit unit 251 Synchronization channel detection unit 252 Broadcast channel reception unit 253 Downlink L1 / L2 control channel receiving unit 254 Downlink shared channel receiving unit 261 to 264 Resource demapping unit 271, 272 FFT unit 281, 282 CP removing unit 291 First receiving circuit 292 Second receiving circuit

Claims (8)

A frequency band allocated for radio communication between a radio base station apparatus and a mobile terminal apparatus is divided into a first basic frequency block to which an FDD scheme is applied, and the first basic frequency block to which a TDD scheme or a half duplex FDD scheme is applied. A wireless communication system configured to perform carrier aggregation with a second basic frequency block having different frequencies,
The radio base station apparatus receives a first downlink L1 / L2 control signal corresponding to the first basic frequency block and a second downlink L1 / L2 control signal corresponding to the second basic frequency block, Assign to downlink radio resources in one of the first fundamental frequency block or the second fundamental frequency block,
The radio base station apparatus frequency multiplexes a downlink L1 / L2 control signal corresponding to the other basic frequency block in a downlink shared channel region in the one basic frequency block. The radio base station apparatus transmits the first uplink L1 / L2 control signal corresponding to the first downlink L1 / L2 control signal and / or the first basic frequency block to the second basic frequency block. Assigned to radio resources in
In one transmission time interval of radio resources in the second basic frequency block, the first downlink L1 / L2 control signal and / or the first uplink L1 / L2 control signal for a plurality of transmission time intervals The radio communication system according to claim 1, wherein the radio communication system is allocated in a concentrated manner.   The radio base station apparatus allocates a synchronization channel and PBCH to downlink radio resources in the first basic frequency block, and the mobile terminal apparatus allocates PRACH to uplink radio resources in the first basic frequency block. The wireless communication system according to claim 1.   The mobile terminal apparatus receives a first uplink L1 / L2 control signal corresponding to the first basic frequency block and a second uplink L1 / L2 control signal corresponding to the second basic frequency block, The radio communication system according to claim 1, wherein the radio communication system is assigned to a PUCCH set in an uplink radio resource in the first basic frequency block.   In the PUCCH, the mobile terminal apparatus includes a subframe to which the first uplink L1 / L2 control signal and the second uplink L1 / L2 control signal are allocated, and the first uplink L1 / L2 control. The radio communication system according to claim 4, wherein a different PUCCH format is used in a subframe to which a signal is allocated and the second uplink L1 / L2 control signal is not allocated. A frequency band allocated for radio communication between a radio base station apparatus and a mobile terminal apparatus is divided into a first basic frequency block to which an FDD scheme is applied, and the first basic frequency block to which a TDD scheme or a half duplex FDD scheme is applied. A wireless communication method configured to perform carrier aggregation with a second basic frequency block having different frequencies,
In the radio base station apparatus, a first downlink L1 / L2 control signal corresponding to the first basic frequency block and a second downlink L1 / L2 control signal corresponding to the second basic frequency block are: Allocating to downlink radio resources in one of the first fundamental frequency block or the second fundamental frequency block;
The radio base station apparatus comprises a step of frequency multiplexing a downlink L1 / L2 control signal corresponding to the other basic frequency block in a downlink shared channel region in the one basic frequency block. Wireless communication method. A wireless base station device that performs wireless communication with a mobile terminal device,
A first transmission circuit unit that controls transmission of information to a first fundamental frequency block to which the FDD scheme is applied;
A second transmission circuit unit for controlling transmission of information to a second fundamental frequency block having a frequency different from that of the first fundamental frequency block to which the TDD scheme or the Half duplex FDD scheme is applied;
A resource mapping unit that performs allocation to the first fundamental frequency block and the second fundamental frequency block that configure a frequency band that is allocated to radio communication with the mobile terminal device and is carrier-aggregated. ,
The resource mapping unit receives the first downlink L1 / L2 control signal corresponding to the first basic frequency block and the second downlink L1 / L2 control signal corresponding to the second basic frequency block, Assign to downlink radio resources in one of the first fundamental frequency block or the second fundamental frequency block,
The radio base station apparatus, wherein the resource mapping unit frequency multiplexes a downlink L1 / L2 control signal corresponding to the other basic frequency block in a downlink shared channel region in the one basic frequency block. A mobile terminal apparatus that performs radio communication with a radio base station apparatus,
A first receiving circuit unit that controls reception of information with respect to a first fundamental frequency block to which the FDD scheme is applied;
A second receiving circuit unit that controls reception of information with respect to a second fundamental frequency block having a frequency different from that of the first fundamental frequency block to which the TDD scheme or the Half duplex FDD scheme is applied;
A resource mapping unit that performs allocation to the first basic frequency block and the second basic frequency block that configure a frequency band that is allocated to radio communication with the radio base station apparatus and is carrier-aggregated; And
The first downlink L1 / L2 control signal corresponding to the first fundamental frequency block and the second downlink L1 / L2 control signal corresponding to the second fundamental frequency block are the first fundamental frequency block. Or assigned to downlink radio resources in one of the second fundamental frequency blocks,
The mobile terminal apparatus, wherein a downlink L1 / L2 control signal corresponding to the other basic frequency block is frequency-multiplexed in the downlink shared channel region in the one basic frequency block.

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