JP2008011157A - Mobile station device and base station device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make it possible to perform an efficient random access using a preamble of an optimum length. <P>SOLUTION: Depending on a wireless propagation channel condition (e.g., receiving electric power) between mobile station devices 10-a to 10-c and a base station device 20, and on a distance from the base station device 20; the mobile station devices 10-a to 10-c vary a transmission frame structure (a preamble length) of a condition base channel CBCH to perform the random access. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mobile station device that randomly accesses a base station device using a preamble, and a base station device that accepts random access from the mobile station device.

  As a third generation cellular mobile communication system, there is a W-CDMA (Wideband Code Division Multiple Access) communication standard standardized in 3GPP (3rd Generation Partnership Project), an international standardization project. Telephone service has been started in each country. In 3GPP, a communication technology called EUTRA (Evolved Universal Terrestrial Radio Access) is being studied as an evolution of such a third generation radio system.

  For the downlink of EUTRA, OFDM (Orthogonal Frequency Division Multiplexing) is used, and adaptive modulation and coding scheme (AMCS) technology based on adaptive radio link control such as channel coding is applied. Yes. In order to efficiently perform high-speed packet data transmission, AMCS is an error correction method, an error correction coding rate, a data modulation multi-value number, a time and frequency axis according to the propagation path status of each mobile station. This is a communication method for switching various wireless transmission parameters (hereinafter referred to as AMC mode) such as the code spreading rate of the first code and the multi-code multiplexing number. For example, in data modulation, as the propagation path condition becomes better, QPSK (4-phase phase shift keying) to 8PSK (8-phase phase shift keying), 16QAM (16-value quadrature amplitude modulation), etc. have higher efficiency. By switching to multi-level modulation, the maximum throughput of the communication system can be increased.

  In addition, for the uplink of EUTRA, a single carrier communication scheme that is superior in PAPR (Peak to Average Power Ratio) characteristics as compared to a multicarrier communication scheme such as the OFDM scheme is used. In particular, a DFT-S-OFDM (Discrete Fourier Transform Spread OFDM) system has been proposed as a single carrier communication system that can use the same parameters as those of the downlink (see, for example, Non-Patent Document 1).

FIG. 16 shows uplink and downlink channel configurations in EUTRA.
In the figure, the downlink of EUTRA includes a downlink pilot channel (DownLink Pilot Channel; DPiCH), a Downlink Synchronization Channel (Downlink Synchronization Channel; DSCH), a Downlink Common Control Channel (Downlink Common Control Channel; and Downlink Channel Channel). And a downlink shared control signaling channel (DSCSCH) and a downlink shared data channel (DSDCH) (see Non-Patent Document 2).

The downlink pilot channel DPiCH includes a downlink common pilot channel (Downlink Common Pilot Channel; DCPiCH) and a downlink dedicated pilot channel (Downlink Dedicated Pilot Channel; DDPICH).
The downlink common pilot channel DCPiCH is used for estimation of downlink radio channel characteristics in the AMCS scheme, cell search, and channel loss measurement for uplink transmission power control. The downlink dedicated pilot channel DDPiCH is shared by the downlink as necessary when transmitting by an antenna having a radio channel characteristic different from that of a cell shared antenna such as an adaptive array antenna or when transmitting to a mobile station with low reception quality. This is used for reinforcing the pilot channel DCPiCH.

  The downlink synchronization channel DSCH is used for mobile station cell search and OFDM symbol timing synchronization such as OFDM signal radio frame, time slot, and TTI (Transmission Time Interval).

  The downlink common control channel DCCCH transmits common control information such as broadcast information, paging indicator information, paging information, and downlink access information.

  The downlink shared control signaling channel DSCSCH is a channel shared by a plurality of mobile stations, and information (modulation scheme, spreading code, etc.) necessary for demodulation processing in each mobile station, error correction decoding processing, HARQ (Hybrid Automatic Repeat request) Used to transmit information necessary for hybrid automatic retransmission request) and scheduling information of radio resources (frequency and time).

  The downlink shared data channel DSDCH is used for transmission of packet data addressed to the mobile station from the upper layer.

  In FIG. 16, the uplink of EUTRA includes an uplink pilot channel (UPiCH), a contention-based channel (CBCH), and an uplink scheduling channel (UPCH). (Refer nonpatent literature 3).

The uplink pilot channel UPiCH is used for estimation of uplink radio propagation path characteristics in the AMCS scheme.
The contention base channel CBCH is a channel corresponding to a random access channel in the W-CDMA system. The random access will be described later.

  The uplink scheduling channel USCH is composed of an uplink shared control signaling channel (Uplink Shared Control Channel; USCSCH) and an uplink shared data channel (Uplink Shared Data Channel; USDCH), and is used in common by each mobile station. It is. The uplink shared control signaling channel USCSCH transmits downlink channel quality information (Channel Quality Indicator; CQI), feedback information such as HARQ, uplink pilot and uplink channel control information, and the like. The uplink shared data channel USDCH transmits packet data from each mobile station.

FIG. 17 shows a radio frame configuration used in the EUTRA downlink. The downlink radio frame has a two-dimensional map with a frequency axis chunk and a time axis TTI.
For example, on the frequency axis, when the frequency bandwidth of the entire downlink is 20 MHz and the frequency bandwidth per chunk is 1.25 MHz, this radio frame includes 16 chunks. On the time axis, when one radio frame is set to 10 ms and TTI is set to 0.5 ms, the radio frame includes 20 TTIs. Note that the radio signal is transmitted by a subcarrier whose frequency is divided into a plurality, but the chunk is configured as a group of several subcarriers.

  In FIG. 17, the downlink common pilot channel DCPiCH is mapped at the head of each TTI, and the downlink shared control signaling channel DSCSCH is mapped behind the TTI. Also, the downlink common control channel DCCCH and the downlink synchronization channel DSCH are mapped to the first TTI (TTI_1 in FIG. 17) of the radio frame. Further, when necessary depending on the antenna usage status of the base station and the propagation path status of the mobile station, the downlink dedicated pilot channel DDPiCH is mapped to an appropriate position in the TTI (in FIG. 17, TTI_1 and Chunk_2 of Chunk_1). To TTI_2).

  In FIG. 17, the packet data addressed to each mobile station is transmitted on the downlink shared data channel DSDCH according to the chunk allocated according to the propagation path condition of the mobile station. For example, based on the assignment of one chunk to one mobile station (user), scheduling that assigns multiple chunks to a mobile station with good radio channel characteristics provides a multi-user diversity effect, and the entire system Throughput can be improved. Also, allocation is performed in units of multiple chunks and one sub TTI (TTI subdivided slot), and it is continuous for mobile stations with poor radio propagation path characteristics, such as existing at a cell boundary or moving at high speed. By allocating a plurality of chunks and performing communication using a wide frequency band, a frequency diversity effect can be obtained and reception characteristics can be improved.

FIG. 18 shows a radio frame configuration used in the uplink of EUTRA. Similarly to the downlink of FIG. 17, the uplink radio frame has a two-dimensional map based on a frequency axis chunk and a time axis TTI.
In FIG. 18, the uplink pilot channel UPiCH is mapped to the beginning and end of the TTI to which the uplink scheduling channel USCH is mapped. In accordance with the uplink pilot channel UPiCH, the base station performs radio channel estimation and mobile station / base station synchronization detection.

  Further, the contention base channel CBCH and the uplink scheduling channel USCH are multiplexed and mapped using a method such as TDM (time division multiplexing) or TDM-FDM (time division multiplexing / frequency division multiplexing). FIG. 19 shows an example of this mapping. FIG. 4A shows an example of multiplexing by TDM-FDM, and FIG. 4B shows an example of multiplexing by TDM. 18 shows the case of the TDM scheme, and uplink scheduling channel USCH is mapped to TTI_1, TTI_3..., And contention base channel CBCH is mapped to TTI_2, TTI_4.

FIG. 20 shows a configuration of transmission frames of uplink scheduling channel USCH and contention base channel CBCH.
In the uplink scheduling channel USCH, a mobile station scheduled by the base station can transmit packet data to the base station according to a chunk allocated according to the propagation path condition of the mobile station. The transmission frame is composed of six long blocks and two short blocks (FIG. 20A). Further, the transmission frame of the contention base channel CBCH has a guard time for absorbing a shift in transmission timing from the mobile station behind the predetermined transmission data ((b) and (c) in the figure). .

In the mobile communication system, the transmission timing of the mobile station is synchronized so that the reception timing at the base station is constant. The contention base channel CBCH is used for this synchronization purpose.
Access to the contention base channel CBCH is called random access. As a method of random access to the contention base channel CBCH, a method of transmitting only the preamble part for measuring a transmission timing shift between the base station and the mobile station (FIG. 20B), or a base station / mobile station A method for transmitting a preamble part for measuring the synchronization timing between them and a message part including control information such as information necessary for scheduling (FIG. 20C) has been proposed (for example, Non-Patent Document 4, 5). When transmitting data not scheduled by the base station, the mobile station performs random access to the contention base channel CBCH according to these methods, and realizes communication with the base station.

FIG. 21 is a sequence diagram showing a procedure for random access to the contention base channel CBCH. When only the preamble part is used ((a) in the figure), after the preamble is detected by the base station, the message part is transmitted using the allocated resource. When using a preamble part and a message part ((b) in the figure), these are transmitted simultaneously.
“3GPP TR (Technical Report) 25.814 V1.2.0 Physical Layer Aspects for Evolved UTRA”, February 2006 Physical Channel and Multiplexing in Evolved UTRA Downlink, “3GPP TSG RAN WG1 Meeting # 42”, August 2005, R1-050707 Physical Channel and Multiplexing in Evolved UTRA Uplink, “3GPP TSG RAN WG1 Meeting # 42”, August 2005, R1-050850 Random Access Transmission for Scalable Multiple Bandwidth in Evolved UTRA Uplink, “3GPP TSG RAN WG1 Meeting # 43”, November 2005, R1-051391 E-UTRA Random Access, “3GPP TSG RAN WG1 Meeting # 43”, November 2005, R1-051445

  In the random access to the contention base channel CBCH, the method of transmitting only the preamble part has a longer preamble length than the method of transmitting the preamble part and the message part (see FIGS. 20B and 20C). ), The accuracy with which the base station detects the preamble transmitted from the mobile station existing at the cell boundary is increased, and good communication quality can be obtained. However, on the other hand, since the message part necessary for scheduling is transmitted separately from the preamble part (see FIG. 21A), until the mobile station can start data transmission. Will take longer.

  Conversely, in the method of transmitting the preamble part and the message part, the message is transmitted at the same time as the preamble, so that the mobile station can start data transmission early. However, since the preamble length is short, the preamble detection accuracy in the base station is lowered.

  Thus, when the preamble length is fixed, there is a problem that an optimum preamble corresponding to the mobile station cannot be used and efficient random access cannot be performed.

  Furthermore, the mobile station existing at the cell boundary and the mobile station existing near the cell center have different radio propagation path conditions and transmission power, and there is a difference in the amount of data that can be transmitted. That is, when information necessary for scheduling is determined with reference to a mobile station existing in the vicinity of the cell center, the mobile station at the cell boundary cannot transmit a message part. Even if the message is transmitted, the base station may not be able to demodulate the message part. In addition, when information necessary for scheduling is determined based on mobile stations existing at cell boundaries, the amount of data that can be transmitted is small, and scheduling information is also limited.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a mobile station apparatus capable of performing efficient random access using a preamble having an optimum preamble length, and the mobile station apparatus. An object of the present invention is to provide a base station apparatus that accepts random access.

  In order to solve the above-described problem, the mobile station apparatus according to the present invention provides a first preamble that is shared as the same data with the base station apparatus when no channel assignment is received from the base station apparatus. In the mobile station apparatus that transmits to the base station apparatus in a predetermined frame of the channel of the channel, channel estimation means for estimating the propagation path characteristics with the base station apparatus, and based on the propagation path characteristics estimated by the channel estimation means Control means for setting a ratio of the preamble occupying the frame, and preamble generation means for generating a preamble according to the set ratio.

  In the present invention, an optimum preamble length is selected according to the propagation path characteristics between the base station and the mobile station, and random access is performed using the preamble having the preamble length.

  The mobile station apparatus of the present invention, when not receiving channel assignment from the base station apparatus, transmits a preamble shared as the same data with the base station apparatus in a predetermined frame of the first channel. In a mobile station apparatus that transmits to a base station apparatus, a means for specifying a distance to the base station apparatus, a control means for setting a ratio of the preamble to the frame based on the specified distance, Preamble generating means for generating a preamble according to a set ratio is provided.

  In the present invention, an optimum preamble length is selected according to the distance between the base station and the mobile station, and random access is performed using the preamble having the preamble length.

  Further, the mobile station apparatus of the present invention includes a data control unit that arranges data including predetermined control information in a portion other than the preamble in the frame, and an encoding unit that encodes the data using a predetermined encoding method. Modulation means for modulating the encoded data by a predetermined modulation method, and means for transmitting the modulated data multiplexed with the preamble, and the control means includes the encoding method and the coding method. At least one of the modulation schemes is set corresponding to the ratio, and the set scheme is instructed to a corresponding unit of the encoding unit and / or the modulation unit.

  In the present invention, an encoding and / or modulation scheme for data transmitted during random access is selected according to the propagation path characteristics or distance between the base station and the mobile station.

In the mobile station apparatus of the present invention, the channel estimation means obtains the propagation path characteristic based on received power measured using a second channel that is a downlink channel from the base station apparatus. Features.
In the mobile station apparatus of the present invention, the means for specifying the distance receives a GPS signal, measures the position of the mobile station apparatus, and the position of the base station apparatus notified from the base station apparatus A distance from the base station apparatus is specified based on the information.

  In order to solve the above problems, a base station apparatus according to the present invention is a base station apparatus that receives a signal from the mobile station apparatus, and detects a preamble transmitted from the mobile station apparatus. Detecting means; calculating means for calculating a ratio of the preamble to an uplink frame including the detected preamble; and encoding data to be transmitted to the mobile station apparatus in downlink using a predetermined encoding method Encoding means and modulation means for modulating the encoded data with a predetermined modulation scheme, and setting the encoding scheme and / or the modulation scheme based on the calculated preamble ratio It is characterized by that.

  According to the present invention, since an optimum preamble length is selected according to the propagation path characteristic or distance between the base station and the mobile station, efficient random access can be performed between the mobile station apparatus and the base station apparatus. it can.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a diagram illustrating a state in which a mobile station apparatus 10 according to an embodiment of the present invention is accommodated in one cell formed by a base station apparatus 20 and performs random access to a contention base channel CBCH. It is assumed that three mobile station apparatuses 10-a to 10-c (MS1 to MS3) having different distances from the base station apparatus 20 (BS) exist in this cell. Each mobile station apparatus 10-a to 10-c performs random access by changing the configuration of the transmission frame of the contention base channel CBCH according to the state of the radio propagation path with the base station apparatus 20.

  Specifically, since the mobile station apparatus 10-a exists in the immediate vicinity of the base station apparatus 20, and the propagation path condition is good, the mobile station apparatus 10-a is connected to the contention base channel CBCH. The N symbols (N: natural number) at the beginning of one TTI are randomly accessed as a preamble part and the rest as a message part and a data part. Also, the mobile station apparatus 10-b, which is a little away from the base station apparatus 20, has a slightly deteriorated propagation path condition, so that the first M symbols (M: natural number, where M> N) of the TTI are used as a preamble. Random access using the rest as a message part. Also, since the mobile station apparatus 10-c that is further away from the base station apparatus 20 and close to the cell boundary has a poor propagation path condition, one TTI is used to maximize the detection accuracy of the preamble. The entire P symbol (P: natural number, where P> M) is used as the preamble part.

  In this way, by changing the preamble length of the contention base channel CBCH according to the radio propagation path condition, for example, the distance between the base station and the mobile station, and performing random access, a mobile station with a good propagation path condition uses fewer symbols. In addition to transmitting the preamble part, the message part and the data part can also be transmitted, and in mobile stations with poor propagation path conditions, the preamble part is transmitted using more symbols to improve the detection accuracy at the base station Can do.

  On the other hand, when the base station apparatus 20 of FIG. 1 detects a preamble in the contention base channel CBCH, the base station apparatus 20 determines the preamble length, extracts the message part and the data part if necessary, and then configures the received transmission frame. The process according to is executed. That is, the base station apparatus 20 returns an appropriate response to the mobile station apparatus according to the preamble length of the preamble portion transmitted by each mobile station apparatus 10-a to 10-c.

  FIG. 2 shows a transmission frame configuration of the contention base channel CBCH and represents one TTI. In the figure, a transmission frame can accommodate six symbols, and a guard time is provided at the end for absorbing a transmission timing shift at the mobile station at the base station. It is assumed that the guard time is set to 1 symbol or less. The transmission frame in FIG. 2 (a) includes a preamble part (2 symbols), a message part (2 symbols), and a data part (2 symbols), and is transmitted by the mobile station apparatus 10-a in FIG. It corresponds to. Also, the transmission frame in FIG. 2B is composed of a preamble part (4 symbols) and a message part (2 symbols), and corresponds to the transmission frame from the mobile station apparatus 10-b. In addition, the transmission frame of FIG. 2C is configured with all six symbols as a preamble part, and corresponds to the transmission frame of the mobile station apparatus 10-c.

  Note that the preamble portion of FIG. 2 is obtained by repeating a preamble of one symbol by the number of symbols, and a sequence with good autocorrelation characteristics such as a CAZAC (Constant Amplitude Zero Auto-Correlation) sequence can be used. The message part is a part for storing control information related to layer 1 (physical layer), and scheduling by random access is performed according to this control information. Specifically, identification information of the mobile station, information indicating the reason for access to the contention base channel CBCH, scheduling request information, information on transmission power of the mobile station or reception power from the base station, and the like are stored. . The data part stores control information and user data of higher layers (such as the MAC layer).

  The mobile station apparatuses 10-a to 10-c appropriately select the transmission frames shown in FIGS. 2A to 2C according to the radio channel conditions, for example, the channel estimation result and the distance between the base station and the mobile station. And random access to the contention base channel CBCH.

  FIG. 3 is a block diagram showing a functional configuration of the mobile station apparatus 10. The mobile station apparatus 10 includes a data control unit 101, a channel encoding unit 102, a data modulation unit 103, a DFT-S-OFDM modulation unit 104, a synchronization correction unit 105, a preamble generation unit 106, and a pilot generation unit. 107, a radio unit 108, a channel estimation unit 109, an OFDM demodulation unit 110, a channel decoding unit 111, a control data extraction unit 112, a scheduling unit 113, and a CBCH control unit 114.

  In FIG. 3, transmission data and control data are input to the data control unit 101. The data control unit 101 transmits the transmission data, control data, and CQI information sent from the channel estimation unit 109 on the contention base channel CBCH or the uplink scheduling channel USCH according to the instructions of the scheduling unit 113 and the CBCH control unit 114. Place it in a format for

The channel coding unit 102 is AMC information (information for designating the AMC mode) sent from the scheduling unit 113 and the CBCH control unit 114. Specifically, the error coding method, the error correction coding rate, Data is encoded using the encoding method specified in the data modulation multi-level number, the time and frequency axis code spreading factor, and the information specifying the multi-code multiplexing number).
Data modulation section 103 modulates data using the modulation scheme specified in the AMC information sent from scheduling section 113 and CBCH control section 114.

  The DFT-S-OFDM modulation unit 104 performs serial / parallel conversion processing, spreading code and scrambling code multiplication processing, DFT conversion processing, subcarrier mapping processing, IFFT (inverse) on the data input from the data modulation unit 103. DFT-S-OFDM signal processing such as discrete Fourier transform (CP) processing, CP (Cyclic Prefix) insertion processing, and filtering processing is performed to generate a DFT-S-OFDM signal. Subcarrier mapping is performed based on mapping information sent from the scheduling section 113 and the CBCH control section 114. The DFT-S-OFDM modulation unit 104 also multiplexes the preamble from the preamble generation unit 106 and the pilot from the pilot generation unit 107 with the modulated data (DFT-S-OFDM signal).

The synchronization correction unit 105 determines transmission timing based on the synchronization information sent from the control data extraction unit 112, and outputs data to the radio unit 108 at the determined transmission timing.
Radio section 108 up-converts uplink data to a radio frequency and transmits the radio data to base station apparatus 20. Also, downlink data from the base station apparatus 20 is received, down-converted to a baseband signal, and then supplied to the OFDM demodulator 110 and the channel estimator 109.

  The channel estimation unit 109 estimates downlink radio channel characteristics based on the downlink pilot channel DPiCH of data input from the radio unit 108, and the OFDM demodulator 110 and the CBCH control as a downlink radio channel estimation result To the unit 114. This downlink radio channel estimation result is used to determine the preamble length of the preamble part when the CBCH control unit 114 performs random access to the contention base channel CBCH. For example, Es / Io can be used for the downlink radio channel estimation result. Here, Es is the OFDM reception energy of the downlink pilot channel DPiCH, and Io is the interference signal power density. The channel estimation unit 109 also converts the downlink radio channel estimation result into CQI information and supplies the CQI information to the data control unit 101 and the scheduling unit 113.

The OFDM demodulator 110 demodulates the received data input from the radio unit 108 based on the downlink radio channel estimation result from the channel estimation unit 109 and the downlink AMC information sent from the control data extraction unit 112.
Channel decoding section 111 decodes received data based on downlink AMC information sent from control data extraction section 112.

  The control data extraction unit 112 separates the received data into control data (downlink shared control signaling channel DSCSCH and downlink common control channel DCCCH) and user data. Then, the downlink AMC information included in the control data is supplied to the OFDM demodulator 110 and the channel decoder 111. Also, uplink AMC information and scheduling information are sent to the scheduling unit 113, and control information related to the contention base channel CBCH (for example, the position of the contention base channel CBCH and the type of preamble that can be used) are sent to the CBCH control unit 114. Are supplied to the synchronization correction unit 105.

  Scheduling section 113 performs uplink scheduling based on scheduling information from the upper layer, uplink AMC information and scheduling information from control data extraction section 112, and CQI information from channel estimation section 109, and data The controller 101, the channel encoder 102, the data modulator 103, and the DFT-S-OFDM modulator 104 are instructed to perform scheduling.

  When access to the contention base channel CBCH is required, the CBCH control unit 114 receives an instruction from the scheduling unit 113 and transmits in the uplink based on the downlink radio channel estimation result from the channel estimation unit 109 The preamble length of the preamble portion, the message length, and the data length are determined. In addition, the determined result is instructed to data control section 101, channel coding section 102, data modulation section 103, and DFT-S-OFDM modulation section 104. The determined preamble length is instructed to the preamble generation unit 106.

  Note that the CBCH control unit 114 may determine the preamble length using not only the downlink radio channel estimation result of the own cell but also the downlink radio channel estimation result of another cell. Further, by using position measurement means such as GPS (Global Positioning System) instead of the downlink radio propagation path estimation result, the distance between the mobile station apparatus 10 and the base station apparatus 20 is calculated and the distance is calculated. The corresponding preamble length may be determined.

The preamble generation unit 106 generates a preamble having a preamble length instructed from the CBCH control unit 114, and supplies the preamble to the DFT-S-OFDM modulation unit 104.
Pilot generation section 107 generates a pilot instructed from base station apparatus 20 and supplies the pilot to DFT-S-OFDM modulation section 104.

  3 assumes the DFT-S-OFDM method as the uplink communication method, but other single carriers such as VSCRF-CDMA (Variable Spreading and Chip Repetition Factor-CDMA). It does not matter if it is a method. Further, a multicarrier system such as an OFDM system may be used.

  FIG. 4 is a block diagram showing a functional configuration of the base station apparatus 20. The base station apparatus 20 includes a data control unit 201, a channel coding unit 202, an OFDM modulation unit 203, a radio unit 204, a channel estimation unit 205, a synchronization detection unit 206, a preamble detection unit 207, and a DFT- It has an S-OFDM demodulation unit 208, a data demodulation unit 209, a channel decoding unit 210, a control data extraction unit 211, and a scheduling unit 212.

  In FIG. 4, transmission data and control data are input to the data control unit 201. The data control unit 201 maps the input 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 according to the instruction from the scheduling unit 212, Data to be transmitted to each mobile station apparatus is mapped to the downlink shared data channel DSDCH. The mapped data is input to channel coding section 202.

Channel encoding section 202 encodes data using the encoding scheme specified in the AMC information sent from scheduling section 212.
The OFDM modulation unit 203 performs data modulation processing, serial / parallel conversion processing, spreading code and scrambling code multiplication processing, IFFT processing, CP insertion processing, filtering processing, and the like on the data input from the channel coding unit 202. OFDM signal processing is performed to generate an OFDM signal. At this time, in the data modulation process, modulation is performed based on the modulation scheme specified by the AMC information sent from the scheduling unit 212.

  The radio unit 204 up-converts the OFDM-modulated data to a radio frequency and transmits it to the mobile station apparatuses 10-a to 10-c. Further, after receiving uplink data from the mobile station devices 10-a to 10-c and down-converting it to a baseband signal, the received data is converted into a DFT-S-OFDM demodulation unit 208, a channel estimation unit 205, The data is supplied to the synchronization detection unit 206 and the preamble detection unit 207.

  The channel estimation unit 205 estimates an uplink radio channel characteristic based on the uplink pilot channel UPiCH of data input from the radio unit 204, and outputs a DFT-S-OFDM demodulation unit as an uplink radio channel estimation result 208 and the scheduling unit 212. This downlink radio channel estimation result is used by the scheduling unit 212 to perform uplink scheduling.

  The synchronization detection unit 206 detects a synchronization shift (transmission timing shift) in the mobile station apparatus based on the preamble included in the uplink pilot channel UPiCH or the contention base channel CBCH of the data input from the radio unit 204, The synchronization error information is supplied to the DFT-S-OFDM demodulation unit 208 and the data control unit 201.

  The preamble detection unit 207 identifies whether or not a preamble has been transmitted on the contention base channel CBCH. When a preamble is detected, the preamble detection unit 207 determines the preamble length and the presence or absence of a message part and a data part. To do. Then, a preamble detection result (information indicating each position of the preamble part, the message part, and the data part in the transmission frame) is supplied to the DFT-S-OFDM demodulation part 208 and the scheduling part 212, and the message part and the data part Are supplied to the data demodulator 209 and the channel decoder 210.

  The DFT-S-OFDM demodulation unit 208 receives received data (DFT-S) input from the radio unit 204 based on the uplink radio channel estimation result from the channel estimation unit 205 and the synchronization shift information from the synchronization detection unit 206. -OFDM signal) is demodulated. Also, for the reception data of the contention base channel CBCH, based on the preamble detection result sent from the preamble detection unit 207, the preamble part and the message part are separated from the reception data. Then, the demodulated reception data and message part are supplied to the data demodulation part 209.

The data demodulator 209 demodulates received data based on the uplink AMC information sent from the control data extractor 211. For the reception data of the contention base channel CBCH, the message part and the data part are demodulated based on the AMC information sent from the preamble detection part 207.
The channel decoding unit 210 decodes received data based on uplink AMC information sent from the control data extraction unit 211. As for the reception data of the contention base channel CBCH, the message part and the data part are decoded based on the AMC information sent from the preamble detection part 207.

  The control data extraction unit 211 separates the received data into control data (uplink shared control signaling channel USCSCH) and user data (uplink shared data channel USDCH). Then, the uplink AMC information included in the control data is supplied to the data demodulation section 209 and the channel decoding section 210, and the downlink CQI information is supplied to the scheduling section 212.

The scheduling unit 212 includes a DL (Downlink) scheduling unit 212a that performs downlink scheduling and a UL (Uplink) scheduling unit 212b that performs uplink scheduling.
DL scheduling section 212a is for mapping user data to each downlink channel based on CQI information sent from the mobile station apparatus and notified by control data extracting section 211 and scheduling information from the higher layer. Scheduling information is generated and instructed to the data control unit 201. Also, the AMC mode applied in the encoding process in channel encoding section 202 and the modulation process in OFDM modulation section 203 is determined based on the CQI information, and is notified to channel encoding section 202 and OFDM modulation section 203.

  The UL scheduling unit 212b maps user data to each uplink channel according to the uplink radio channel estimation result from the channel estimation unit 205 and the resource allocation request from each mobile station apparatus 10-a to 10-c. Scheduling information is generated, and the AMC mode of encoding processing and modulation processing used in the mobile station apparatus is determined. These scheduling information and AMC mode information are input to the data control unit 201 as control data.

Next, processing (algorithm) in which the CBCH control unit 114 of the mobile station apparatus 10 determines the preamble length will be described. As described above, the CBCH control unit 114 determines the preamble length based on the downlink radio channel estimation result, but here, Es / Io is used as the downlink radio channel estimation result.
When the mobile station apparatus 10 performs random access to the contention base channel CBCH, the channel estimation unit 109 measures Es / Io. Then, since the CBCH control unit 114 can determine that the distance between the base station and the mobile station is short when the Es / Io value is large, the CBCH control unit 114 sets the preamble length short. When the Es / Io value is small, it is determined that the distance between the base station / mobile station is long, and the preamble length is set to be long. In this way, by varying the preamble length according to the Es / Io value, the contention-based channel CBCH can be randomly accessed by an optimum method according to the state of the radio propagation path.

  A specific example is shown in FIG. In the example of FIG. 5, when the Es / Io value is X or more, the preamble is 2 symbols, when the Es / Io value is Y or more and less than X, the preamble is 4 symbols, and the Es / Io value is less than Y. In this case, the preamble is 6 symbols. As a result, the transmission frame of the contention base channel CBCH has the form shown in FIG.

  Also, the preamble length can be determined based on the propagation path loss between the base station and the mobile station. In this case, when the mobile station apparatus 10 performs random access to the contention base channel CBCH, the channel estimation unit 109 measures the downlink reception energy Es, and the transmission power of the base station apparatus 20 from the downlink common control channel DCCCH. Is calculated, the propagation path loss between the base station and the mobile station is calculated. Then, the CBCH control unit 114 determines that the distance between the base station and the mobile station is short if the propagation path loss is small, and sets the preamble length to be short. If the propagation path loss is large, it is determined that the distance between the base station and the mobile station is long, and the preamble length is set long.

  A specific example is shown in FIG. In the example of FIG. 6, when the channel loss is less than L, the preamble is 2 symbols, when the channel loss is L or more and less than M, the preamble is 4 symbols, and when the channel loss is M or more. The preamble is 6 symbols. As a result, the transmission frame of the contention base channel CBCH has the form shown in FIG.

  Furthermore, it is also possible to determine the preamble length by using the downlink radio channel estimation result of another cell. When the mobile station apparatus 10 performs random access to the contention base channel CBCH, the channel estimation unit 109 measures the downlink reception energy Es1 of its own cell and the downlink reception energy Es2 of another cell, and the ratio Es1 / Es2 Is calculated. Then, when Es1 / Es2 is close to 1, the CBCH control unit 114 determines that the own device (mobile station device) exists near the middle of the own cell and another cell, that is, at the cell boundary, and sets the preamble longer. To do. When Es1 / Es2 is close to 0, it is determined that the cell is in the vicinity of the base station apparatus of the own cell, and the preamble length is set short.

  A specific example is shown in FIG. In the example of FIG. 7, when Es1 / Es2 is less than S (eg, 0.3), the preamble is 2 symbols, and when Es1 / Es2 is greater than S and less than T (eg, 0.8), the preamble is 4 symbols. If Es1 / Es2 is equal to or greater than T, the preamble is 6 symbols. As a result, the transmission frame of the contention base channel CBCH has the form shown in FIG.

Next, processing in which the preamble detection unit 207 of the base station apparatus 20 detects a preamble will be described. Here, the preamble is assumed to be known in the base station device 20 and the mobile station device 10. In addition, it is assumed that the reception frame is composed of 6 symbols (see FIG. 2).
FIG. 8 is a flowchart showing the procedure of preamble detection processing.

  In FIG. 8, the preamble detection unit 207 first detects the cross-correlation of the second symbol of the frame received by the contention base channel CBCH (step S101). The obtained correlation value of the second symbol is compared with a predetermined value γ (preamble threshold) (step S102), and if it is equal to or larger than γ, it is determined that the preamble is included in the frame (preamble is detected). The process proceeds to step S103. If it is less than γ, it is determined that the preamble is not included in the frame (step S108).

  Next, the cross correlation detection of the fourth symbol is performed (step S103). The correlation value of the fourth symbol and the correlation value of the second symbol (or the average value of the correlation values of the first symbol and the second symbol) are compared (step S104), and the correlation value of the fourth symbol is smaller than the correlation value of the second symbol. In this case, the third symbol (and subsequent symbols) is determined as the message part (step S109). If the correlation value of the fourth symbol is greater than or equal to the correlation value of the second symbol, it is determined that the third and subsequent symbols are also preambles, and the process proceeds to step S105.

  Similarly, the cross correlation detection of the sixth symbol is performed (step S105). The correlation value of the sixth symbol and the correlation value of the second symbol (or the average value of the correlation values of the first symbol and the second symbol) are compared (step S106), and the correlation value of the sixth symbol is smaller than the correlation value of the second symbol. In this case, the fifth symbol (and the subsequent symbols) is determined as the message part (step S110). If the correlation value of the sixth symbol is greater than or equal to the correlation value of the second symbol, it is determined that all the frames (6 frames) are preambles (step S107).

FIG. 9 is a diagram for conceptually explaining the preamble detection. Here, it is assumed that the received frame is synchronized with the clock of the base station apparatus 20.
FIG. 9A shows a case where the preamble length is 2 symbols. In the cross-correlation detection of the second symbol, since the second symbol is a preamble part, a value equal to or greater than γ is obtained as the correlation value. Therefore, the preamble is detected. Next, in the cross-correlation detection of the fourth symbol, the correlation value is 0 because the fourth symbol is a message part. As a result of the comparison between the fourth symbol and the second symbol, the third and subsequent symbols are determined as message parts. That is, it is determined that the preamble length is 2 symbols.

  FIG. 9B shows a case where the preamble length is 4 symbols. In the cross-correlation detection of the second symbol, since the second symbol is a preamble part, a value equal to or greater than γ is obtained as the correlation value. Therefore, the preamble is detected. Next, in the cross-correlation detection of the fourth symbol, since the fourth symbol is also a preamble part, the same correlation value as that of the second symbol is obtained, and it is determined that the third and subsequent symbols are also preamble parts. Further, in the cross-correlation detection of the sixth symbol, the correlation value is 0 because the sixth symbol is a message part. Then, by comparing the sixth symbol and the second symbol, the message portion, that is, the preamble length is determined to be 4 symbols after the 5th symbol.

  FIG. 9C shows a case where the preamble length is 6 symbols. In the cross-correlation detection of the second symbol, since the second symbol is a preamble part, a value equal to or greater than γ is obtained as the correlation value. Therefore, the preamble is detected. Next, in the cross-correlation detection of the fourth symbol, since the fourth symbol is also a preamble part, the same correlation value as that of the second symbol is obtained, and it is determined that the third and subsequent symbols are also preamble parts. Further, in the cross-correlation detection of the sixth symbol, since the sixth symbol is also a preamble part, the same correlation value as that of the second symbol is obtained, and the entire frame is determined to be a preamble (preamble length is 6 symbols).

FIG. 10 is a diagram conceptually illustrating preamble detection as in FIG. 9, and shows a case where the received frame is shifted by half of one symbol with respect to the clock of the base station apparatus 20.
FIG. 10A shows a case where the preamble length is 2 symbols. Since the received frame and the clock are not synchronized, a high correlation value (the same value as in FIG. 9) is obtained for the second symbol. A low correlation value is obtained for the third and third symbols. Also in this case, as in FIG. 9A, the correlation value of the fourth symbol (= 0) is smaller than the correlation value of the second symbol, so the preamble length is determined to be 2 symbols.

FIG. 10B shows a case where the preamble length is 4 symbols. In this case, a high correlation value is obtained for the second to fourth symbols, and a low correlation value is obtained for the first and third symbols. Similarly to FIG. 9B, the correlation value of the fourth symbol is equal to the second symbol, and the correlation value of the sixth symbol (= 0) is smaller than the correlation value of the second symbol, so the preamble length is 4 symbols. It is determined.
FIG. 10C shows a case where the preamble length is 6 symbols. In this case, a high correlation value is obtained for the second to sixth symbols, and a low correlation value is obtained for the first and seventh symbols. Similarly to FIG. 9C, since the correlation values of the fourth symbol and the sixth symbol are equal to those of the second symbol, the preamble length is determined to be 6 symbols.

Next, another example of processing in which the preamble detection unit 207 of the base station apparatus 20 detects a preamble will be described with reference to the flowchart of FIG.
In FIG. 22, the preamble detection unit 207 first detects autocorrelation of the first symbol and the second symbol of the frame received by the contention base channel CBCH (step S201). The obtained autocorrelation value is compared with a predetermined value δ (preamble threshold value) (step S202). If it is equal to or larger than δ, it is determined that the preamble is included in the frame, and the process proceeds to step S203. If it is less than δ, it is determined that no preamble is included in the frame (step S208).

  Next, autocorrelation detection of the second symbol and the third symbol is performed (step S203). The obtained autocorrelation value is compared with a predetermined value δ (preamble threshold value) (step S204). If it is equal to or larger than δ, it is determined that the third and subsequent symbols include the preamble, and the process proceeds to step S205. . If it is less than δ, the third symbol (and the subsequent symbols) is determined as the message part (step S209).

  Similarly, autocorrelation detection is performed for the fourth symbol and the fifth symbol (step S205). The obtained autocorrelation value is compared with a predetermined value δ (preamble threshold) (step S206), and if it is equal to or larger than δ, it is determined that the preamble is included in the fifth and subsequent symbols, and the process proceeds to step S210. . If it is less than δ, the fifth symbol (and the subsequent symbols) is determined as the message part (step S210).

FIG. 23 conceptually illustrates the preamble detection described above. Here, it is assumed that the received frame is synchronized with the clock of the base station apparatus 20.
FIG. 23A shows a case where the preamble length is 2 symbols. In the autocorrelation detection of the first and second symbols, since the first and second symbols are the preamble part, a value of δ or more is obtained as the correlation value. Therefore, the preamble is detected. Next, in the autocorrelation detection of the second and third symbols, the correlation value is 0 because the third symbol is a message part. As a result, the third and subsequent symbols are determined as message parts. That is, it is determined that the preamble length is 2 symbols.

  FIG. 23B shows a case where the preamble length is 4 symbols. In the autocorrelation detection of the first and second symbols, since the first and second symbols are the preamble part, a value of δ or more is obtained as the correlation value. Therefore, the preamble is detected. Next, in the autocorrelation detection of the second and third symbols, since the third symbol is also a preamble part, the same correlation value as that of the first and second symbols is obtained, and it is determined that the third and subsequent symbols are also preamble parts. Further, in the autocorrelation detection of the fourth and fifth symbols, since the fifth symbol is a message part, the correlation value is 0, and the fifth and subsequent symbols are determined to have a message part, that is, a preamble length of four symbols.

  FIG. 23C shows a case where the preamble length is 6 symbols. In the cross correlation detection of the first and second symbols, since the first and second symbols are the preamble part, a value equal to or larger than δ is obtained as the correlation value. Therefore, the preamble is detected. Next, in the autocorrelation detection of the second and third symbols, since the third symbol is also a preamble part, the same correlation value as that of the first and second symbols is obtained, and it is determined that the third and subsequent symbols are also preamble parts. Furthermore, in the autocorrelation detection of the fourth and fifth symbols, since the fifth symbol is also a preamble part, the same correlation value as that of the first and second symbols is obtained, and the entire frame is determined to be a preamble (preamble length is 6 symbols). .

  Next, processing of each device when the mobile station device 10 performs random access using the contention base channel CBCH and the base station device 20 and the mobile station device 10 start communication will be described.

  First, the mobile station apparatus 10 determines the preamble length from the downlink Es / Io in the CBCH control unit 114. Then, according to this preamble length, the format of transmission data at the time of random access is determined. Specifically, one is selected from FIGS. 2 (a) to 2 (c). For example, if the preamble length is 6 symbols, random access is performed in the format of FIG. In this case, only the preamble generated by the preamble generation unit 106 is modulated by the DFT-S-OFDM modulation unit 104 and transmitted from the radio unit 108 via the contention base channel CBCH. In the case of FIG. 2 (a) or (b), the message part and the data part are input to the data control part 101, and after the modulation and the preamble part are multiplexed by the DFT-S-OFDM modulation part 104, Send.

  Thereafter, the mobile station apparatus 10 waits for a response from the base station apparatus 20 for a certain waiting time. This waiting time is Tb when the preamble length is 2 symbols, and Ta when the preamble length is 4 or 6 symbols. However, Ta <Tb.

  When the preamble detection unit 207 detects the preamble of the contention base channel CBCH, the base station apparatus 20 grasps the presence or absence of a message part or a data part based on the preamble length of the determination result, and the DFT-S-OFDM demodulation part 208, data Each process of the demodulation part 209, the channel decoding part 210, and the control data extraction part 211 is performed. The data part is sent to the upper layer.

  The base station apparatus 20 also returns a response to the mobile station apparatus 10 according to the preamble length information determined by the preamble detection unit 207 and notified to the scheduling unit 212. Then, the base station device 20 and the mobile station device 10 perform the sequence of FIG.

  Specifically, when the preamble length is 6 symbols (see FIG. 2C), the sequence of FIG. 11C is performed. That is, the base station device 20 has not yet transmitted the synchronization error information between the base station / mobile station obtained from the synchronization detection unit 206 and the message unit when the mobile station device 10 is the message unit (FIG. 2C). ) Is transmitted to the mobile station apparatus 10 within the period of Ta. When receiving the response, the mobile station device 10 generates a message part. The message part is input to the data control part 101 and is sequentially processed by the channel coding part 102, the data modulation part 103, and the DFT-S-OFDM modulation part 104. Then, the mobile station apparatus 10 performs synchronization correction on the message part by the synchronization correction unit 105, and then transmits the message part with the resource (the transmission frame of the specified time and frequency) specified by the resource allocation information. It transmits to the base station apparatus 20. Thereafter, similarly, when the base station apparatus 20 receives the message part, the mobile station apparatus 10 transmits resource allocation information for transmitting data to the mobile station apparatus 10. The mobile station apparatus 10 receives this response and starts transmitting data using the designated resource (uplink scheduling channel USCH).

  When the preamble length is 4 symbols (see FIG. 2B), the sequence in FIG. 11B is performed. That is, the base station apparatus 20 obtains the synchronization error information between the base station and the mobile station obtained from the synchronization detection unit 206 and the uplink resource allocation information for the mobile station apparatus 10 to transmit data within the period of Ta. To the mobile station device 10. The mobile station apparatus 10 performs synchronization correction by the synchronization correction unit 105 and then starts data transmission on the resource (uplink scheduling channel USCH) specified by the resource allocation information.

  When the preamble length is 2 symbols (see FIG. 2A), the sequence of FIG. 11A is performed. That is, the base station apparatus 20 passes the data part of the received frame to the upper layer and waits for a response from the upper layer. After the response, the synchronization error information between the base station / mobile station, the uplink resource allocation information for the mobile station device 10 to transmit data, and the response result from the higher layer to the data part within the period of Tb To the mobile station device 10. The mobile station apparatus 10 performs synchronization correction by the synchronization correction unit 105 and then starts data transmission on the resource (uplink scheduling channel USCH) specified by the resource allocation information.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.
The mobile station apparatus 10 according to this embodiment performs adaptive modulation in addition to appropriately selecting the preamble length according to the radio propagation path condition. Since the configuration of the mobile station apparatus 10 is the same as that in FIG. 3, only the CBCH control unit 114 having a different operation will be described below.

A process in which the mobile station apparatus 10 according to the present embodiment determines an AMC mode for performing preamble length and adaptive modulation will be described. The AMC mode is a modulation method of a message part and a data part used in the data modulation part 103 here.
When the mobile station apparatus 10 performs random access to the contention base channel CBCH, the channel estimation unit 109 measures Es / Io. Then, since the CBCH control unit 114 can determine that the distance between the base station and the mobile station is short when the Es / Io value is large, the CBCH control unit 114 sets the preamble length short. Further, since the distance between the base station and the mobile station is short, it is determined that the radio channel variation is small, and a modulation scheme with a high modulation degree is set. On the other hand, when the Es / Io value is small, it is determined that the distance between the base station and the mobile station is long, and the preamble length is set long. Also, since the distance between the base station and the mobile station is long, it is determined that the radio channel variation is large, and a modulation scheme with a low modulation degree is set.

  A specific example is shown in FIG. In the example of FIG. 12, when the Es / Io value is X or more, the preamble is 2 symbols, and the modulation method is 16QAM. When the Es / Io value is Y or more and less than X, the preamble is 4 symbols and the modulation method is QPSK. When the Es / Io value is less than Y, the preamble is 6 symbols (there are no message part and data part, so no modulation scheme is set).

  As in the first embodiment, the preamble length and the AMC mode (modulation scheme) can be determined using downlink CQI information and GPS information instead of Es / Io. Moreover, you may utilize the radio | wireless propagation path estimation result of an own cell and another cell.

In the present embodiment, since the configuration of the base station apparatus 20 is the same as that in FIG. 4, only the preamble detection unit 207 having a different operation will be described. Further, the preamble detection method of the base station apparatus 20 is the same as that in the first embodiment.
The preamble detection unit 207 identifies whether or not a preamble has been transmitted on the contention base channel CBCH. When a preamble is detected, the preamble detection unit 207 determines the preamble length and the presence / absence of a message part and a data part. To do. Further, the AMC mode to be applied to the message part and the data part is also determined based on the determined preamble length. Then, the preamble detection result (information indicating each position of the preamble part, the message part, and the data part in the transmission frame) is supplied to the DFT-S-OFDM demodulation unit 208 and the scheduling unit 212, and the determined AMC mode is supplied. The AMC information shown is supplied to the data demodulation unit 209 and the channel decoding unit 210. In accordance with the AMC information determined by the preamble detector 207 and notified to the data demodulator 209, the data demodulator 209 demodulates the message part and the data part.

  According to the present embodiment, since the mobile station apparatus 10 modulates the message part and the data part using a modulation scheme with a high degree of modulation when the radio channel condition is good, a large number of contention base channels CBCH are used. It is possible to send data.

(Third embodiment)
Next, a third embodiment of the present invention will be described.
The mobile station apparatus according to this embodiment includes position measurement means using GPS, and calculates a preamble length corresponding to the distance by calculating a distance between the base station and the mobile station from the measured position information.
FIG. 13 is a block diagram showing a functional configuration of the mobile station apparatus 11 according to the present embodiment. In the figure, the functions and operations of components other than the channel estimation unit 109, the control data extraction unit 112, the CBCH control unit 114, and the GPS reception unit 115 described below are the same as those in the first embodiment. Is omitted.

The GPS receiving unit 115 receives a predetermined GPS signal from a GPS satellite, measures the position of the mobile station device 11 based on the received GPS signal, and supplies the position information to the CBCH control unit 114.
The channel estimation unit 109 estimates downlink radio channel characteristics based on the downlink pilot channel DPiCH of data input from the radio unit 108 and supplies the downlink radio channel characteristics to the OFDM demodulation unit 110 as a downlink radio channel estimation result. . Further, the downlink radio channel estimation result is converted into CQI information and supplied to the data control unit 101 and the scheduling unit 113. It differs from the first embodiment in that the downlink radio channel estimation result is supplied only to the OFDM demodulator 110.

  The control data extraction unit 112 separates the received data into control data (downlink shared control signaling channel DSCSCH and downlink common control channel DCCCH) and user data. Then, the downlink AMC information included in the control data is supplied to the OFDM demodulator 110 and the channel decoder 111. Also, uplink AMC information and scheduling information are sent to the scheduling unit 113, control information related to the contention base channel CBCH and location information of the base station apparatus 20 are sent to the CBCH control unit 114, uplink synchronization information is sent to the synchronization correction unit 105, Supply each. It differs from the first embodiment in that the location information of the base station apparatus 20 included in the received control data is supplied to the CBCH control unit 114.

  When access to the contention base channel CBCH is required, the CBCH control unit 114 receives an instruction from the scheduling unit 113 and receives the location information of the mobile station apparatus 11 from the GPS reception unit 115 and the control data extraction unit 112. The distance between the base station and the mobile station is calculated from the position information of the base station apparatus 20, and the preamble length of the preamble part to be transmitted in the uplink and the AMC mode of the message part and the data part are determined based on the calculated distance. . In addition, the determined result is instructed to data control section 101, channel coding section 102, data modulation section 103, and DFT-S-OFDM modulation section 104. The determined preamble length is instructed to the preamble generation unit 106. The first embodiment is different from the first embodiment in that a preamble length and the like are determined based on position information obtained by GPS.

Next, processing in which the CBCH control unit 114 of the mobile station apparatus 11 determines the preamble length will be described.
When the mobile station apparatus 10 performs random access to the contention base channel CBCH, the GPS receiving unit 115 measures the position of the mobile station apparatus 11 to obtain position information. The CBCH control unit 114 calculates the distance between the base station and the mobile station based on the location information of the mobile station device 11 and the location information of the base station device 20 sent from the control data extraction unit 112. Then, the CBCH control unit 114 sets the preamble length to be short when the distance between the base station / mobile station is short. When the distance between the base station / mobile station is long, the preamble length is set long.

  FIG. 14 shows a specific example. In the example of FIG. 14, when the distance between the base station and the mobile station is less than P (m), the preamble is set to 2 symbols, and the distance between the base station and the mobile station is greater than or equal to P (m) and less than Q (m). In this case, the preamble is 4 symbols, and when the distance between the base station and the mobile station is Q (m) or more, the preamble is 6 symbols. As a result, the transmission frame of the contention base channel CBCH has the form shown in FIG.

In addition to appropriately selecting the preamble length according to the distance between the base station / mobile station, adaptive modulation can also be executed.
A specific example is shown in FIG. In the example of FIG. 15, when the distance between the base station and the mobile station is less than P (m), the preamble is 2 symbols and the modulation scheme is 16QAM. Further, when the distance between the base station and the mobile station is P (m) or more and less than Q (m), the preamble is set to 4 symbols and the modulation method is set to QPSK. When the Es / Io value is Q (m) or more, the preamble is 6 symbols (there are no message part and data part, so no modulation scheme is set).

As described above, the embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to the above, and various design changes and the like can be made without departing from the scope of the present invention. It is possible to
For example, instead of directly determining the preamble length, the ratio of the preamble to the transmission frame may be determined.
In addition, although the case of adaptive modulation has been described as the second embodiment, the coding scheme of the channel coding unit can be set according to the radio propagation path condition.

It is the figure explaining a mode that the mobile station apparatus by one Embodiment of this invention performs random access. It is a block diagram of the transmission frame of the contention base channel CBCH. It is a block diagram which shows the functional structure of the mobile station apparatus by one Embodiment of this invention. It is a block diagram which shows the functional structure of a base station apparatus. This is a first example of setting the preamble length by the CBCH control unit. This is a second example of setting the preamble length by the CBCH control unit. It is the example 3 of the setting of the preamble length by a CBCH control part. It is the flowchart which showed the procedure of the preamble detection process in a base station apparatus. FIG. 9 is a diagram conceptually illustrating the preamble detection of FIG. 8 (when frames are synchronized). FIG. 9 is a diagram conceptually illustrating the preamble detection in FIG. 8 (when frames are not synchronized). It is a sequence diagram of random access performed by a mobile station apparatus and a base station apparatus. It is the example 4 of the setting of the preamble length by a CBCH control part. It is a block diagram which shows the functional structure of the mobile station apparatus by the 2nd Embodiment of this invention. This is a fifth example of setting the preamble length by the CBCH control unit. This is a sixth example of setting the preamble length by the CBCH control unit. It is a channel configuration diagram of uplink and downlink in EUTRA. It is a radio | wireless frame structure used in the downlink of EUTRA. It is a radio | wireless frame structure used in the uplink of EUTRA. It is a figure explaining multiplexing of the channel in an uplink. It is a figure which shows the structure of the transmission frame of the uplink scheduling channel USCH and the contention base channel CBCH. It is the sequence diagram which showed the procedure of the random access to the contention base channel CBCH. It is the flowchart which showed the procedure of the preamble detection process in a base station apparatus. FIG. 23 is a diagram for conceptually explaining the preamble detection of FIG. 22 (when frames are synchronized).

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 11 Mobile station apparatus 20 Base station apparatus 101 Data control part 102 Channel encoding part 103 Data modulation part 104 DFT-S-OFDM modulation part 105 Synchronization correction part 106 Preamble generation part 107 Pilot generation part 108 Radio part 109 Channel estimation part DESCRIPTION OF SYMBOLS 110 OFDM demodulation part 111 Channel decoding part 112 Control data extraction part 113 Scheduling part 114 CBCH control part 115 GPS receiving part 201 Data control part 202 Channel encoding part 203 OFDM modulation part 204 Radio | wireless part 205 Channel estimation part 206 Synchronization detection part 207 Preamble detection unit 208 DFT-S-OFDM demodulation unit 209 Data demodulation unit 210 Channel decoding unit 211 Control data extraction unit 212 Scheduling unit

Claims (6)

In a mobile station apparatus that transmits a preamble shared as the same data with the base station apparatus to the base station apparatus in a predetermined frame of the first channel when channel assignment is not received from the base station apparatus ,
Channel estimation means for estimating propagation path characteristics with the base station device;
Control means for setting a proportion of the preamble in the frame based on propagation path characteristics estimated by the channel estimation means;
Preamble generation means for generating a preamble according to the set ratio;
A mobile station apparatus comprising: In a mobile station apparatus that transmits a preamble shared as the same data with the base station apparatus to the base station apparatus in a predetermined frame of the first channel when channel assignment is not received from the base station apparatus ,
Means for specifying a distance between the base station device;
Control means for setting a proportion of the preamble in the frame based on the specified distance;
Preamble generation means for generating a preamble according to the set ratio;
A mobile station apparatus comprising: Data control means for arranging data including predetermined control information in a portion other than the preamble in the frame;
Encoding means for encoding the data by a predetermined encoding method;
Modulation means for modulating the encoded data by a predetermined modulation method;
Means for multiplexing and transmitting the modulated data with the preamble;
With
The control means sets at least one of the encoding scheme and the modulation scheme in correspondence with the ratio, and instructs the corresponding means of the encoding means and / or modulation means to set the scheme. The mobile station apparatus according to claim 1 or 2. 2. The movement according to claim 1, wherein the channel estimation unit obtains the propagation path characteristic based on reception power measured using a second channel that is a downlink channel from the base station apparatus. Station equipment. The means for specifying the distance receives a GPS signal, measures the position of the mobile station apparatus, and based on the position and the position information of the base station apparatus notified from the base station apparatus, The mobile station apparatus according to claim 2, wherein a distance between the mobile stations is specified. A base station device that receives a signal from the mobile station device according to any one of claims 1 to 5,
Preamble detecting means for detecting a preamble transmitted from the mobile station device;
Calculation means for calculating a ratio of the preamble to an uplink frame including the detected preamble;
Encoding means for encoding data to be transmitted in the downlink to the mobile station apparatus by a predetermined encoding method;
Modulation means for modulating the encoded data by a predetermined modulation method;
A base station apparatus, wherein the coding scheme and / or the modulation scheme are set based on the calculated preamble ratio.

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