JP4864731B2 - Radio base station apparatus and radio terminal apparatus - Google Patents

Description

  The present invention relates to a radio base station apparatus and a radio terminal apparatus.

  In recent years, a standardization project "3GPP: 3rd Generation Partnership Project" has been examining standards for third generation (3G) mobile communication systems. FIG. 9 shows a hierarchical structure on a communication protocol between a radio base station and a radio terminal under examination by 3GPP. Layer 1 (L1) is composed of a PHY layer (Physical Layer). Layer 2 (L2) is composed of a MAC (Media Access Control) layer and an RLC (Radio Link Control) layer. Layer 3 (L3) is composed of an RRC (Radio Resource Control) layer. In the RLC layer, RLC retransmission control is performed between the radio base station and the radio terminal. In the RRC layer, radio resource allocation is performed between the radio base station and the radio terminal.

  Category 1 (Category) in the L1 / L2 control signal of the downlink of the orthogonal frequency division multiplexing (OFDM) system (link in the direction from the radio base station to the radio terminal) is one of the issues to be studied in 3GPP 0) The configuration of information is being studied (see Non-Patent Documents 1 and 2). FIG. 10 shows the configuration of a downlink L1 / L2 control channel in the OFDM scheme (see Non-Patent Document 3). In FIG. 10, L1 / L2 control channels (“Cat.0” and “Control” portions in FIG. 10) are arranged within three OFDM symbols from the head in one subframe. Further, immediately after the L1 / L2 control channel, a data channel (Shared Data channel, “Data” portion in FIG. 10) is arranged. Accordingly, since the L1 / L2 control channel is arbitrarily arranged, “Category 0” information (“Cat. 0” portion in FIG. 10) indicating the arrangement is provided (see Non-Patent Document 2). In addition, as a user (wireless terminal) multiplexing system of L1 / L2 control channel in the downlink of OFDM system, FDMA (Frequency Division Multiple Access) system and CDMA (Code Division Multiple Access) system A method is being considered. When FDMA is used for user multiplexing, “Category 0” information includes L1 / L2 control symbol allocation information per TTI (Transmission Time Interval) information and MCS (Modulation and Coding Scheme) information. Has been made. Since “Category 0” information is received and decoded by all users, it is very important to consider the number of bits of “Category 0” information.

  In addition, a multi-carrier transmission system has attracted attention as a communication system used in a new generation mobile communication system. Typical examples of the multicarrier transmission scheme include an OFDM (Orthogonal Frequency Division Multiplexing) scheme and an MC-CDM (Multi-Carrier-Code Division Multiplexing) scheme. In Non-Patent Documents 4 and 5, a rotation orthogonal code is proposed as an MC-CDM spreading code. The rotation orthogonal code Rn when the spreading factor is n is expressed by the equation (1). Then, the output signal vector s ′ when the input signal vector s is encoded by the rotation orthogonal code Rn is expressed by the equation (2).

However, M is an integer of 2 or more. Θ is a rotation angle (unit: radians). When the rotation angle θ is set to 0, signal diffusion is not performed and the output signal is an OFDM signal. On the other hand, when the rotation angle θ is set to π / 4, the signal is spread evenly, and the output signal becomes an MC-CDM system signal using Walsh codes. In addition, by changing the rotation angle θ to a value between 0 and π / 4, the signal spreading ratio can be changed and the frequency diversity effect can be controlled. The MC-CDM method using OFDM and Walsh codes Both features can be obtained.
3GPP TR 25.814 v7.1.0, “Physical layer aspects for evolved UTRA,” September 2006. 3GPP TSC RAN1 WG1 # 47, R1-063070, “E-UTRA DL L1 / L2 Control Channel Information fields & bit requirements,” November 2006. 3GPP TSG RAN WG1, “Draft Report of 3GPP TSG RAN WG1 # 47 v.0.2.0,” January 2007. 3GPP TSG RAN WG1 # 42bis, R-051261, “Enhancement of Distributed Mode for Maximizing Frequency Diversity,” October 2005. 3GPP TSG RAN WG1 # 47, R1-063349, “L1 / L1 Control Channel Structure with CDM Based Multiplexing in E-UTRA Downlink,” November 2006.

  However, when the CDMA scheme is used as the user multiplexing scheme of the L1 / L2 control channel in the downlink of the OFDM scheme, how to configure “Category 0” information is a problem. When using CDMA as the user multiplexing method of L1 / L2 control channel in the downlink of OFDM method, as in FDMA method, “Category 0” information, L1 / L2 control symbol allocation number information per MTI and MCS information Is mentioned. Therefore, it is preferable that the “Category 0” information is compatible so that it can be used when either the CDMA system or the FDMA system is used. However, when the CDMA system is used, the same spreading factor must be used in the radio base station device and the radio terminal device, so it is necessary to share the spreading factor used in the radio base station device and the radio terminal device. is there. For this reason, it is conceivable that the spreading factor is included in the “Category 0” information and transmitted from the radio base station apparatus to the radio terminal apparatus, but the compatibility of the “Category 0” information with the FDMA scheme is lost.

  The present invention has been made in consideration of such circumstances, and its purpose is to use a radio base station apparatus when a CDMA system is used as a user multiplexing system for L1 / L2 control channels in the downlink of the OFDM system. An object of the present invention is to provide a radio base station apparatus and a radio terminal apparatus capable of composing "Category 0" information having a common spreading factor used in radio terminal apparatuses and compatible with the FDMA scheme.

  In order to solve the above problems, a radio base station apparatus according to the present invention is a radio base station apparatus that uses a CDMA scheme as a user multiplexing scheme of L1 / L2 control channels in an OFDM scheme downlink. Spreading factor calculation means for calculating the maximum available spreading factor from the number of transmission bits per user, the number of subcarriers allocated per TTI, the modulation rate determined for each modulation scheme, and the coding rate And multiplexing means for performing code division multiplexing according to the calculated spreading factor for the control information of each user, and information on the number of subcarriers allocated per TTI, modulation scheme, and coding rate are “Category 0” Transmitting means for wirelessly transmitting to the wireless terminal apparatus together with the code division multiplexed signal included in the information is provided.

  A radio terminal apparatus according to the present invention, in a radio terminal apparatus that uses a CDMA scheme as a user multiplexing scheme of L1 / L2 control channels in an OFDM scheme downlink, assigns subcarriers per TTI, modulation scheme, and coding rate. "Category 0" information including the above information is received from a radio base station apparatus together with a code division multiplexed signal, information included in the "Category 0" information, and transmission per user determined in advance A spreading factor calculating unit that calculates the maximum available spreading factor from the number of bits, a separating unit that performs despreading on the code division multiplexed signal according to the calculated spreading factor, and the despreading unit An acquisition means for obtaining control information addressed to the own apparatus from the demodulated data is provided.

  A radio base station apparatus according to the present invention uses a CDMA scheme and an FDMA scheme as user multiplexing schemes for L1 / L2 control channels in an OFDM downlink, and spreads the control information for each user. "Category 0" information for multiplexing means for performing code division multiplexing according to the rate and frequency division multiplexing according to the number of frequency divisions, and the number of subcarriers allocated per TTI, modulation scheme, coding rate, and spreading rate information And transmitting means for wirelessly transmitting to the wireless terminal device together with the multiplexed signals of the code division multiplexing and the frequency division multiplexing.

  A radio terminal apparatus according to the present invention uses a CDMA scheme and an FDMA scheme as a user multiplexing scheme of an L1 / L2 control channel in an OFDM scheme downlink, and the number of subcarriers allocated per TTI, a modulation scheme, “Category 0” information including coding rate and spreading rate information is received from a radio base station apparatus together with code division multiplexed and frequency division multiplexed signals, and is included in the “Category 0” information. Frequency division number calculating means for calculating the number of frequency divisions from information and a predetermined number of transmission bits per user, and for each multiplexed signal in each frequency region corresponding to the calculated frequency division number Separation means for performing despreading according to the spreading factor included in the “Category 0” information, and acquisition means for obtaining control information addressed to the device from the despread demodulated data Characterized by comprising a.

  A radio base station apparatus according to the present invention uses a CDMA scheme and an FDMA scheme as user multiplexing schemes for L1 / L2 control channels in an OFDM downlink, and spreads the control information for each user. “Category 0” is information on multiplexing means that performs code division multiplexing according to rate and frequency division multiplexing according to frequency division number, and the number of subcarriers allocated per TTI, modulation scheme, coding rate, and information on the frequency division number. Transmitting means for wirelessly transmitting to the wireless terminal device together with the multiplexed signals of the code division multiplexing and frequency division multiplexing included in the information is provided.

  A radio terminal apparatus according to the present invention uses a CDMA scheme and an FDMA scheme as a user multiplexing scheme of an L1 / L2 control channel in an OFDM scheme downlink, and the number of subcarriers allocated per TTI, a modulation scheme, "Category 0" information including information on coding rate and frequency division number is included in the "Category 0" information, and receiving means for wirelessly receiving from a radio base station apparatus together with multiplexed signals of code division multiplexing and frequency division multiplexing And a predetermined number of transmission bits per user, a spreading factor calculating means for calculating a spreading factor, and depending on the frequency division number included in the “Category 0” information for the multiplexed signal Separating means for performing despreading in accordance with the calculated spreading factor in each frequency domain, and obtaining means for obtaining control information addressed to the own apparatus from the despread demodulated data. Characterized in that was.

  A radio base station apparatus according to the present invention uses a CDMA scheme as a user multiplexing scheme of L1 / L2 control channels in an OFDM scheme downlink, according to a spreading factor for control information of each user Multiplexing means for performing code division multiplexing, information on the number of subcarriers allocated per TTI, modulation scheme and coding rate information included in "Category 0" information and wirelessly transmitted to the wireless terminal device together with the code division multiplexed signal, Transmission means for wirelessly transmitting to the wireless terminal device including the spreading factor in L3 information.

  A radio terminal apparatus according to the present invention, in a radio terminal apparatus that uses a CDMA scheme as a user multiplexing scheme of L1 / L2 control channels in an OFDM scheme downlink, assigns subcarriers per TTI, modulation scheme, and coding rate. "Category 0" information including the above information is wirelessly received from the radio base station apparatus together with the code division multiplexed signal, and L3 information including the spreading factor is wirelessly received from the radio base station apparatus; and the code Separation means for performing despreading on the division multiplexed signal according to the spreading factor included in the L3 information, and acquisition means for obtaining control information addressed to the device from the despread demodulated data Features.

  A radio base station apparatus according to the present invention uses a CDMA scheme and an FDMA scheme as user multiplexing schemes for L1 / L2 control channels in an OFDM downlink, and spreads the control information for each user. "Category 0" information includes multiplexing means for performing code division multiplexing according to rate and frequency division multiplexing according to frequency division number, and information on the number of subcarriers allocated per TTI, modulation scheme, and coding rate Transmitting means for wirelessly transmitting to the wireless terminal apparatus together with the multiplexed signals of code division multiplexing and frequency division multiplexing and including the spreading factor in L3 information and wirelessly transmitting to the wireless terminal apparatus.

  A radio terminal apparatus according to the present invention, in a radio terminal apparatus using a CDMA scheme and an FDMA scheme as a user multiplexing scheme of an L1 / L2 control channel in an OFDM scheme downlink, an allocation number of subcarriers per TTI, a modulation scheme, and "Category 0" information including coding rate information is wirelessly received from a radio base station apparatus together with multiplexed signals of code division multiplexing and frequency division multiplexing, and L3 information including a spreading factor is received from the radio base station apparatus. Frequency division number for calculating frequency division number from reception means for wireless reception, information included in the “Category 0” information, spreading factor included in the L3 information, and a predetermined number of transmission bits per user A calculation unit; and a demultiplexing unit that performs despreading on the multiplexed signal according to a spreading factor included in the L3 information in each frequency region corresponding to the calculated frequency division number. And obtaining means for obtaining control information addressed to the apparatus from the despread demodulated data.

  A radio base station apparatus according to the present invention uses a CDMA scheme and an FDMA scheme as user multiplexing schemes for L1 / L2 control channels in an OFDM downlink, and spreads the control information for each user. "Category 0" information includes multiplexing means for performing code division multiplexing according to rate and frequency division multiplexing according to frequency division number, and information on the number of subcarriers allocated per TTI, modulation scheme, and coding rate Transmitting means for wirelessly transmitting to a wireless terminal device together with a multiplexed signal of code division multiplexing and frequency division multiplexing, and including the frequency division number in L3 information and wirelessly transmitting to the wireless terminal device.

  A radio terminal apparatus according to the present invention, in a radio terminal apparatus using a CDMA scheme and an FDMA scheme as a user multiplexing scheme of an L1 / L2 control channel in an OFDM scheme downlink, an allocation number of subcarriers per TTI, a modulation scheme, and “Category 0” information including coding rate information is wirelessly received from a radio base station apparatus together with multiplexed signals of code division multiplexing and frequency division multiplexing, and L3 information including the frequency division number is received. A spreading factor for calculating a spreading factor from receiving means for wirelessly receiving from, information included in the “Category 0” information, frequency division number included in the L3 information, and a predetermined number of transmission bits per user A calculation unit; and a demultiplexing unit that performs despreading according to the calculated spreading factor in each frequency region according to the frequency division number included in the L3 information with respect to the multiplexed signal. And obtaining means for obtaining control information addressed to the apparatus from the despread demodulated data.

  In the radio base station apparatus according to the present invention, the transmission means delays the timing of transmitting “Category 0” information by a time required for demodulation of L3 information in the radio terminal apparatus.

  A radio base station apparatus according to the present invention is a radio base station apparatus that uses a CDMA scheme as a user multiplexing scheme of L1 / L2 control channels in an OFDM downlink, and the number of subcarriers allocated per TTI, a modulation scheme, and a code A mapping table in which spreading factor information is stored in association with the coding rate information, and the spreading factor information associated with the number of subcarriers allocated per TTI, the modulation scheme, and the coding rate information. A spreading factor acquisition unit that acquires from the mapping table; a multiplexing unit that performs code division multiplexing on the control information of each user according to the acquired spreading factor; and a sub-per-TTI used to acquire the spreading factor. Transmission means for wirelessly transmitting to the wireless terminal device together with the code division multiplexed signal, including information on the number of carriers allocated, modulation scheme and coding rate in the “Category 0” information Characterized by comprising a.

  A radio terminal apparatus according to the present invention, in a radio terminal apparatus that uses a CDMA scheme as a user multiplexing scheme of L1 / L2 control channels in an OFDM scheme downlink, assigns subcarriers per TTI, modulation scheme, and coding rate. "Category 0" information including the above information is received in association with the code division multiplexed signal from the radio base station apparatus in association with information on the number of subcarriers allocated per TTI, modulation scheme, and coding rate information. A spreading table that stores spreading factor information, a mapping table that is common to the radio base station apparatus, and a spreading factor that is associated with information included in the “Category 0” information is acquired from the mapping table. From the rate acquisition means, the separation means for performing despreading according to the spreading factor of the acquisition for the code division multiplexed signal, and the despread demodulated data, Characterized by comprising a obtaining means for obtaining control information addressed device.

  A radio base station apparatus according to the present invention uses a CDMA scheme and an FDMA scheme as user multiplexing schemes for L1 / L2 control channels in an OFDM downlink, and the number of subcarriers allocated per TTI, modulation A mapping table in which spreading factor information is stored in association with scheme and coding rate information, and the number of subcarriers allocated per TTI, the spreading factor associated with modulation scheme and coding rate information Spreading factor acquisition means for acquiring information from the mapping table; multiplexing means for performing frequency division multiplexing according to the number of frequency divisions and code division multiplexing according to the acquired spreading factor for the control information of each user; Information on the number of subcarriers allocated per TTI used to acquire the spreading factor, modulation scheme, and coding rate information is included in the “Category 0” information, and the code division With multiplex and multiplex signals of a frequency-division multiplexing characterized by comprising a transmitting means for wireless transmission to the wireless terminal device.

  A radio terminal apparatus according to the present invention, in a radio terminal apparatus using a CDMA scheme and an FDMA scheme as a user multiplexing scheme of an L1 / L2 control channel in an OFDM scheme downlink, an allocation number of subcarriers per TTI, a modulation scheme, and "Category 0" information including coding rate information is received from a radio base station apparatus together with a code division multiplexing and frequency division multiplexing multiplexed signal; a receiving means; the number of subcarriers allocated per TTI, a modulation scheme, and The spreading factor information is stored in association with the coding rate information, the common mapping table with the radio base station apparatus, and the spreading factor associated with the information included in the “Category 0” information. A spreading factor acquiring means for acquiring information from the mapping table; information included in the “Category 0” information; Frequency division number calculating means for calculating the frequency division number from the number of transmission bits per user, and for the multiplexed signal, depending on the obtained spreading factor in each frequency region corresponding to the calculated frequency division number And separating means for performing despreading, and obtaining means for obtaining control information addressed to the apparatus from the despread demodulated data.

  A radio base station apparatus according to the present invention uses a CDMA scheme and an FDMA scheme as user multiplexing schemes for L1 / L2 control channels in an OFDM downlink, and the number of subcarriers allocated per TTI, modulation Mapping table storing frequency division number information in association with scheme and coding rate information, and frequency division associated with number of subcarrier allocations per TTI, modulation scheme and coding rate information Frequency division number acquisition means for acquiring number information from the mapping table, and multiplexing for performing code division multiplexing according to spreading factor and frequency division multiplexing according to the acquired frequency division for each user's control information Information on the number of subcarriers allocated per TTI, the modulation scheme, and the coding rate used for obtaining the frequency division number, and “Category 0 With multiplex signal of said code division multiple and frequency division multiplexing, including the information, characterized in that a transmission means for wirelessly transmitting to the wireless terminal device.

  A radio terminal apparatus according to the present invention, in a radio terminal apparatus using a CDMA scheme and an FDMA scheme as a user multiplexing scheme of an L1 / L2 control channel in an OFDM scheme downlink, an allocation number of subcarriers per TTI, a modulation scheme, and "Category 0" information including coding rate information is received from a radio base station apparatus together with a code division multiplexing and frequency division multiplexing multiplexed signal; a receiving means; the number of subcarriers allocated per TTI, a modulation scheme, and Frequency division number information stored in association with coding rate information, a mapping table common to the radio base station apparatus, and frequency division associated with information included in the “Category 0” information Frequency division number acquisition means for acquiring number information from the mapping table, information included in the “Category 0” information, and the acquisition frequency A spreading factor calculating means for calculating a spreading factor from a divisor and a predetermined number of transmission bits per user, and the calculation in each frequency region corresponding to the frequency division number acquired for the multiplexed signal A demultiplexing unit that performs despreading according to the spreading factor of the device, and an acquisition unit that obtains control information addressed to the own apparatus from the despread demodulated data.

  According to the present invention, when the CDMA scheme is used as the user multiplexing scheme of the L1 / L2 control channel in the downlink of the OFDM scheme, the spreading factor used in the radio base station apparatus and the radio terminal apparatus is shared, and the FDMA The “Category 0” information having compatibility with the method can be configured.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
In the first embodiment, when the CDMA scheme is used as the user multiplexing scheme of the L1 / L2 control channel in the downlink of the OFDM scheme, the radio base station is always used by using the maximum available spreading factor. The spreading factor used by the device and the wireless terminal device is shared. As a result, it is not necessary to provide a spreading factor for “Category 0” information, and compatibility with the FDMA scheme of “Category 0” information is maintained.

FIG. 1 is a block diagram showing a configuration of a radio base station apparatus according to the first embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of the wireless terminal device according to the embodiment.
In FIG. 1, a radio base station apparatus includes an encoder 1 and a modulator 2, a multiplexer 3, an RF circuit 4, an antenna 5, and a Cat. 0 information control unit 6.

  The Cat.0 information control unit 6 uses L1 / L2 control symbol allocation number information per TTI (per TTI) based on communication quality information (FB information) in the uplink (link in the direction from the radio terminal to the radio base station). Subcarrier allocation number information (including subcarrier number information per TTI), MCS information, and spreading factor. The L1 / L2 control symbol allocation number information and MCS information per TTI are “Category 0” information. The MCS information includes information indicating the modulation scheme and coding rate used. For the spreading factor, the maximum available spreading factor is determined. This diffusion rate calculation method will be described later. The communication quality information includes, for example, SIR (Signal to Interference power Ratio) information, BER (Bit Error Rate) information, number of users information, and the like.

  The control information for each user is encoded by the encoder 1 according to a predetermined coding rate, then modulated by the modulator 2 according to a predetermined modulation scheme, and then Cat.0 information. Code division multiplexing (CDM) is performed by the multiplexer 3 in accordance with the spreading factor determined by the control unit 6. Further, the multiplexer 3 multiplexes the code division multiplexed signal and the “Category 0” information. The multiplexed signal output from the multiplexer 3 is frequency-converted to the RF band by the RF circuit 4 and wirelessly transmitted from the antenna 5.

In FIG. 2, the wireless terminal device includes an antenna 11, an RF circuit 12, a data buffer 14, a CDM separator 15, a UE ID search unit 16, a Cat.0 information control unit 17, and a spreading factor calculation unit 18. And a code assigning unit 19.
The radio signal received by the antenna 11 is down-converted by the RF circuit 12 and then separated by the separator 13 into “Category 0” information and control information (code division multiplexed signal) for each user. The control information for each user is temporarily stored in the data buffer 14. “Category 0” information is input to the Cat.0 information control unit 17.

  The Cat.0 information control unit 17 extracts L1 / L2 control symbol allocation number information and MCS information per TTI from “Category 0” information. Then, the Cat.0 information control unit 17 outputs the subcarrier number information per TTI to the separator 13. Also, the Cat.0 information control unit 17 outputs the subcarrier number information per TTI and the MCS information to the spreading factor calculation unit 18.

  The spreading factor calculation unit 18 calculates the maximum available spreading factor based on the number of subcarriers per TTI and the MCS information. The code assignment unit 19 is notified of the spreading factor of the calculation result.

  The code allocating unit 19 creates spreading codes for all users obtained from the spreading factor notified from the spreading factor calculating unit 18. The spreading code is sent to the CDM separator 15.

  The CDM separator 15 despreads the control information of each user extracted from the data buffer 14 with the spreading code of each user. The UE ID search unit 16 searches for “UE ID” of the own device from the despread demodulated data and outputs control information addressed to the own device.

Next, the diffusion rate calculation method according to the present embodiment will be described with a specific example.
As “Category 0” information, the number of subcarriers allocated per TTI is 800, the modulation scheme is QPSK (Quadrature Phase Shift Keying, Quadri-Phase Shift Keying), and the coding rate is 1/2. Information on the number of subcarriers assigned per TTI is included in the information on the number of assigned L1 / L2 control symbols per TTI. Information on the modulation scheme and coding rate is included in the MCS information. Further, it is assumed that the number of transmission bits per user is 50 bits. Note that the number of transmission bits per user is predetermined. In this case, the diffusion rate is
Spreading factor = number of subcarriers allocated per TTI "800" ÷ (number of transmission bits "50" x (1 / coding rate "1/2") x (1 / modulation rate "2")) = 16
It becomes. The modulation rate is determined for each modulation method.
As a result, in the wireless terminal device, the code assignment unit 19 creates 16 spreading codes and sends them to the CDM separator 15. The CDM separator 15 performs despreading using each of the 16 spreading codes.

  According to the first embodiment described above, the “Category 0” information has the same information amount (number of bits) as the FDMA method, and throughput does not decrease.

[Second Embodiment]
In the first embodiment described above, when the CDMA scheme is used as the user multiplexing scheme of the L1 / L2 control channel in the downlink of the OFDM scheme, the maximum available spreading factor is always used. Due to the effects of interference, multi-access interference or frequency diversity, it is not always appropriate to use a large spreading factor to improve radio transmission characteristics. Therefore, in the second embodiment, the CDMA scheme and the FDMA scheme are used in combination as the user multiplexing scheme of the L1 / L2 control channel in the downlink of the OFDM scheme. As a result, it becomes necessary to share the spreading factor and frequency division multiplexing number used in the radio base station apparatus and the radio terminal apparatus. For this reason, in the second embodiment, the spreading factor is included in the “Category 0” information and notified from the radio base station apparatus to the radio terminal apparatus, and the radio terminal apparatus calculates the frequency division multiplexing number from the “Category 0” information. To do. This maintains the compatibility of “Category 0” information in CDMA and FDMA systems.

  FIG. 3 is a block diagram showing a configuration of a radio base station apparatus according to the second embodiment of the present invention. FIG. 4 is a block diagram showing a configuration of the wireless terminal device according to the embodiment.

3, the radio base station apparatus has the same configuration as the radio base station apparatus of FIG. 1, but the functions of the Cat.0 information control unit 6 and the multiplexer 3 are different.
The Cat.0 information control unit 6 uses L1 / L2 control symbol allocation number information (including subcarrier number information per TTI), MCS information, spreading factor and frequency division based on uplink communication quality information. Decide the number. Then, the Cat.0 information control unit 6 includes spreading factor information in the “Category 0” information in addition to the L1 / L2 control symbol allocation number information and MCS information per TTI. The spreading factor information represents the spreading factor. The Cat.0 information control unit 6 notifies the multiplexer 3 of the spreading factor and the frequency division number.

The multiplexer 3 performs code division multiplexing on the modulation signal from each modulator 2 in accordance with the spreading factor determined by the Cat.0 information control unit 6 and the number of frequency divisions determined by the Cat.0 information control unit 6. Depending on the frequency division multiplexing. The frequency division rule corresponding to the number of frequency divisions is determined in advance and is shared by the radio base station apparatus and the radio terminal apparatus.
Further, the multiplexer 3 multiplexes the multiplexed signal and “Category 0” information. The multiplexed signal output from the multiplexer 3 is frequency-converted to the RF band by the RF circuit 4 and wirelessly transmitted from the antenna 5.

4 includes a resource calculation unit 21 and a resource allocation unit 22 instead of the spreading factor calculation unit 18 and the code allocation unit 19 in the radio terminal device of FIG. Further, the functions of the Cat.0 information control unit 17 and the separator 15 are different.
The Cat.0 information control unit 17 extracts L1 / L2 control symbol allocation number information, MCS information, and spreading factor information per TTI from the “Category 0” information from the separator 13. Then, the Cat.0 information control unit 17 outputs the subcarrier number information per TTI to the separator 13. Further, the Cat.0 information control unit 17 outputs the subcarrier number information, MCS information, and spreading factor information per TTI to the resource calculation unit 21.

  The resource calculation unit 21 calculates the number of frequency divisions based on the number of subcarriers per TTI, MCS information, and spreading factor information. The frequency division number and spreading factor information of the calculation result are notified to the resource allocation unit 22.

  The resource allocation unit 22 creates spreading codes for all users obtained from spreading rates based on spreading rate information. The spreading code is sent to the separator 15. Moreover, the resource allocation part 22 produces the information of the frequency domain of all the users obtained from the frequency division number. The frequency domain information is sent to the separator 15. The frequency division rule corresponding to the number of frequency divisions is determined in advance and is shared by the radio base station apparatus and the radio terminal apparatus.

  The separator 15 despreads the control information (code division multiplexed and frequency division multiplexed signals) extracted from the data buffer 14 with the spread code of each user in the frequency domain of each user. The UE ID search unit 16 searches for “UE ID” of the own device from the despread demodulated data and outputs control information addressed to the own device.

Next, the frequency division number calculation method according to the present embodiment will be described with a specific example.
As “Category 0” information, it is assumed that the number of assigned subcarriers per TTI is 800, the modulation scheme is QPSK, the coding rate is 1/2, and the spreading factor is 8. Information on the number of subcarriers assigned per TTI is included in the information on the number of assigned L1 / L2 control symbols per TTI. Information on the modulation scheme and coding rate is included in the MCS information. Further, it is assumed that the number of transmission bits per user is 50 bits. Note that the number of transmission bits per user is predetermined. In this case, the frequency division number is given by
Number of frequency divisions = number of subcarriers allocated per TTI "800" ÷ (number of transmission bits "50" x (1 / coding rate "1/2") x (1 / modulation rate "2") x spreading factor " 8 ”) = 2
It becomes. The modulation rate is determined for each modulation method.
As a result, in the wireless terminal device, the resource allocation unit 22 creates eight spreading codes and two types of frequency domain information and sends them to the separator 15. The separator 15 performs despreading using each of the 16 spreading codes in the two frequency regions.

  According to the second embodiment described above, radio transmission characteristics can be improved by using the CDMA scheme and the FDMA scheme in consideration of the effects of inter-code interference, multi-access interference or frequency diversity. Also, the spreading factor can be adaptively updated by notifying the spreading factor included in the “Category 0” information from the radio base station device to the radio terminal device.

  In the second embodiment described above, the frequency division multiplexing number is included in “Category 0” information and notified from the radio base station apparatus to the radio terminal apparatus, and the spreading factor is calculated by the radio terminal apparatus from “Category 0” information. You may make it do. The calculation method of the spreading factor is the same as the calculation method of the frequency division multiplexing number described above.

[Third Embodiment]
The third embodiment is similar to the second embodiment described above, but sends spreading factor information, which is control information of layer 2 (L2), from the radio base station apparatus to the radio terminal apparatus via layer 3 (L3). Like that.

  FIG. 5 is a block diagram showing a configuration of a radio base station apparatus according to the third embodiment of the present invention. FIG. 6 is a block diagram illustrating a configuration of the wireless terminal device according to the embodiment.

  In FIG. 5, the radio base station apparatus has the same configuration as the radio base station apparatus of FIG. However, the Cat.0 information control unit 6 does not include the spreading factor information in the “Category 0” information, but passes it to the L3 processing unit (not shown). The L3 processing unit includes spreading factor information in the L3 information. As a result, the spreading factor information is included in the L3 information and sent to the wireless terminal device. Therefore, it is the L1 / L2 control symbol allocation number information and MCS information per TTI that are sent to the wireless terminal apparatus in the “Category 0” information.

  In FIG. 6, the wireless terminal device has the same configuration as the wireless terminal device of FIG. However, the Cat.0 information control unit 17 receives spreading factor information from an L3 processing unit (not shown). In the wireless terminal device, the L3 processing unit passes the spreading factor information included in the L3 information transmitted from the wireless base station device to the Cat.0 information control unit 17. The Cat.0 information control unit 17 outputs spreading factor information from the L3 processing unit, subcarrier number information per TTI, and MCS information to the resource calculation unit 21. The subsequent processing is the same as in the second embodiment described above.

  Note that the radio base station apparatus of FIG. 5 may delay the timing of transmitting “Category 0” information in consideration of the time required for the radio terminal apparatus to demodulate the L3 information. Thereby, the wireless terminal device can minimize the delay time in the data buffer 14. Alternatively, the timing adjustment by the data buffer 14 on the wireless terminal device side may be performed instead of giving the transmission timing of the “Category 0” information on the wireless base station device side.

  According to the third embodiment described above, the spread rate information is included in the L3 information and transmitted from the radio base station apparatus to the radio terminal apparatus, so that the information amount of “Category 0” information does not increase and throughput does not decrease. Further, “Category 0” information is referred to by all users, but an increase in the amount of processing required to refer to the information can be prevented, and the effect is great.

  Similarly to the above-described second embodiment, the frequency division multiplexing number may be included in the L3 information and notified from the radio base station apparatus to the radio terminal apparatus, and the radio terminal apparatus may calculate the spreading factor.

  Further, only the CDMA scheme may be used as the user multiplexing scheme of the L1 / L2 control channel in the downlink of the OFDM scheme. In this case, the spreading factor may be included in the L3 information and notified from the radio base station apparatus to the radio terminal apparatus.

[Fourth Embodiment]
The fourth embodiment is similar to the second embodiment described above, but instead of sending spreading factor information from the radio base station device to the radio terminal device, a mapping table for obtaining spreading factor information is provided in the radio base station device. And the wireless terminal apparatus share the spreading factor information from the mapping table in each of the wireless base station apparatus and the wireless terminal apparatus.

  FIG. 7 is a block diagram showing a configuration of a radio base station apparatus according to the fourth embodiment of the present invention. FIG. 8 is a block diagram showing the configuration of the wireless terminal device according to the embodiment.

  In FIG. 7, the radio base station apparatus has the same configuration as the radio base station apparatus of FIG. However, the Cat.0 information control unit 6 has a mapping table for obtaining spreading factor information, and obtains spreading factor information from the mapping table. In the mapping table, spreading factor information is stored in association with information on the number of subcarriers per TTI and MCS information (modulation scheme and coding rate information). The Cat.0 information control unit 6 acquires spreading factor information associated with the number of subcarriers per TTI and the MCS information from the mapping table. The spreading factor information is sent to the multiplexer 3 and used for code division multiplexing.

  The Cat.0 information control unit 6 does not include the spreading factor information in the “Category 0” information. Therefore, the L1 / L2 control symbol allocation number information and MCS information per TTI used for acquiring spreading factor information are included in the “Category 0” information and transmitted to the wireless terminal apparatus.

  In FIG. 8, the wireless terminal device has the same configuration as the wireless terminal device of FIG. However, the mapping unit 31 is provided, and the mapping unit 31 obtains spreading factor information. The mapping unit 31 has a common mapping table with the radio base station device. The Cat.0 information control unit 17 sends the subcarrier number information per TTI and the MCS information obtained from the “Category 0” information from the separator 13 to the mapping unit 31. The mapping unit 31 acquires the spreading factor information associated with the subcarrier number information per MTI and the MCS information from the mapping table. The spreading factor information is sent to the resource calculation unit 21 and used for calculating the frequency division number. The subsequent processing is the same as in the second embodiment described above.

  According to the fourth embodiment described above, since it is not necessary to transmit spreading factor information from the radio base station apparatus to the radio terminal apparatus, not only the “Category 0” information but also the amount of information sent from the radio base station apparatus to the radio terminal apparatus. Will not Increase. Accordingly, there is no decrease in throughput, and an increase in the amount of processing related to user information reference can be prevented. Further, as in the second embodiment, the spreading factor can be updated at the information transmission speed at L2.

  In the fourth embodiment described above, the frequency division multiplexing number may be obtained from the mapping table, and the wireless terminal device may calculate the spreading factor.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like within a scope not departing from the gist of the present invention.
For example, the present invention can be similarly applied to a case where a rotation orthogonal code is used as a CDMA spread code. When a rotation orthogonal code is used as a CDMA spreading code, a new rotation angle is required. Therefore, in each of the above-described embodiments, the rotation angle may be shared between the radio base station apparatus and the radio terminal apparatus in the same manner as the spreading factor sharing method. In the sharing method according to the first embodiment, the best available rotation angle should always be used.

It is a block diagram which shows the structure of the radio base station apparatus which concerns on 1st Embodiment of this invention. It is a block diagram which shows the structure of the radio | wireless terminal apparatus which concerns on the same embodiment. It is a block diagram which shows the structure of the radio base station apparatus which concerns on 2nd Embodiment of this invention. It is a block diagram which shows the structure of the radio | wireless terminal apparatus which concerns on the same embodiment. It is a block diagram which shows the structure of the wireless base station apparatus which concerns on 3rd Embodiment of this invention. It is a block diagram which shows the structure of the radio | wireless terminal apparatus which concerns on the same embodiment. It is a block diagram which shows the structure of the wireless base station apparatus which concerns on 4th Embodiment of this invention. It is a block diagram which shows the structure of the radio | wireless terminal apparatus which concerns on the same embodiment. It is explanatory drawing which shows the hierarchical structure on the communication protocol of a wireless base station and a wireless terminal. It is a block diagram which shows the structure of a L1 / L2 control channel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Encoder, 2 ... Modulator, 3 ... Multiplexer, 6, 17 ... Cat.0 information control part, 14 ... Data buffer, 15 ... Separator, 18 ... Spreading factor calculation part, 19 ... Code allocation part, 21 ... Resource calculation unit, 22 ... Resource allocation unit, 31 ... Mapping unit

Claims (13)

In the radio base station apparatus using the CDMA system as the user multiplexing system of the L1 / L2 control channel in the downlink of the OFDM system,
The maximum available spreading factor is calculated from the predetermined number of transmission bits per user, the number of subcarriers allocated per TTI, the modulation rate determined for each modulation scheme, and the coding rate. Diffusivity calculating means;
Multiplexing means for performing code division multiplexing according to the calculated spreading factor for the control information of each user;
Transmission means for wirelessly transmitting to the wireless terminal device together with the code division multiplexed signal including information on the number of subcarriers allocated per TTI, modulation scheme and coding rate in the “Category 0” information;
A radio base station apparatus comprising: In a wireless terminal device using CDMA as a user multiplexing method of L1 / L2 control channel in OFDM downlink,
Receiving means for wirelessly receiving “Category 0” information including information on the number of subcarriers allocated per TTI, modulation scheme, and coding rate from a radio base station apparatus together with a code division multiplexed signal;
A spreading factor calculating means for calculating the maximum available spreading factor from the information included in the “Category 0” information and a predetermined number of transmission bits per user;
Separating means for despreading the code division multiplexed signal according to the calculated spreading factor;
Obtaining means for obtaining control information addressed to the device from the despread demodulated data;
A wireless terminal device comprising: In a radio base station apparatus that uses CDMA and FDMA as user multiplexing for L1 / L2 control channels in the OFDM downlink,
Multiplexing means for performing code division multiplexing according to spreading factor and frequency division multiplexing according to the number of frequency divisions for each user's control information;
Transmission that includes information on the number of subcarriers allocated per TTI, modulation scheme, coding rate, and spreading factor in “Category 0” information, and is wirelessly transmitted to the wireless terminal device together with the code division multiplexed and frequency division multiplexed multiplexed signals. Means,
A radio base station apparatus comprising: In radio terminal equipment using CDMA and FDMA as user multiplexing for L1 / L2 control channels in OFDM downlink
Reception of "Category 0" information including information on the number of subcarriers allocated per TTI, modulation scheme, coding rate, and spreading factor, as well as multiplexed signals of code division multiplexing and frequency division multiplexing, from a radio base station apparatus Means,
Frequency division number calculating means for calculating a frequency division number from information included in the “Category 0” information and a predetermined number of transmission bits per user;
Separating means for performing despreading according to a spreading factor included in the “Category 0” information in each frequency region according to the calculated frequency division number for the multiplexed signal;
Obtaining means for obtaining control information addressed to the device from the despread demodulated data;
A wireless terminal device comprising: In a radio base station apparatus that uses CDMA and FDMA as user multiplexing for L1 / L2 control channels in the OFDM downlink,
Multiplexing means for performing code division multiplexing according to spreading factor and frequency division multiplexing according to the number of frequency divisions for each user's control information;
Information on the number of subcarriers allocated per TTI, modulation scheme, coding rate, and frequency division number information is included in “Category 0” information and transmitted to the radio terminal apparatus together with the code division multiplexing and frequency division multiplexing multiplexed signals. A transmission means;
A radio base station apparatus comprising: In radio terminal equipment using CDMA and FDMA as user multiplexing for L1 / L2 control channels in OFDM downlink
"Category 0" information including information on the number of subcarriers allocated per TTI, modulation scheme, coding rate, and frequency division number is wirelessly received from the radio base station apparatus together with multiplexed signals of code division multiplexing and frequency division multiplexing. Receiving means;
Spreading factor calculating means for calculating a spreading factor from information included in the “Category 0” information and a predetermined number of transmission bits per user;
Separating means for performing despreading according to the calculated spreading factor in each frequency domain according to the frequency division number included in the “Category 0” information with respect to the multiplexed signal;
Obtaining means for obtaining control information addressed to the device from the despread demodulated data;
A wireless terminal device comprising: In the radio base station apparatus using the CDMA system as the user multiplexing system of the L1 / L2 control channel in the downlink of the OFDM system,
Multiplexing means for performing code division multiplexing according to the spreading factor for the control information of each user;
Information on the number of subcarriers allocated per TTI, modulation scheme, and coding rate is included in “Category 0” information and wirelessly transmitted to the wireless terminal device together with the code division multiplexed signal, and the spreading factor is included in L3 information. Transmitting means for wirelessly transmitting to a wireless terminal device;
A radio base station apparatus comprising: In a wireless terminal device using CDMA as a user multiplexing method of L1 / L2 control channel in OFDM downlink,
"Category 0" information including information on the number of subcarriers allocated per TTI, modulation scheme, and coding rate is wirelessly received from the radio base station apparatus together with the code division multiplexed signal, and L3 information including the spreading factor is received. Receiving means for wirelessly receiving from the wireless base station device;
Separating means for performing despreading according to a spreading factor included in the L3 information with respect to the code division multiplexed signal;
Obtaining means for obtaining control information addressed to the device from the despread demodulated data;
A wireless terminal device comprising: In a radio base station apparatus that uses CDMA and FDMA as user multiplexing for L1 / L2 control channels in the OFDM downlink,
Multiplexing means for performing code division multiplexing according to spreading factor and frequency division multiplexing according to the number of frequency divisions for each user's control information;
Information on the number of subcarriers allocated per TTI, modulation scheme, and coding rate information is included in “Category 0” information, and wirelessly transmitted to the wireless terminal device together with the code division multiplexing and frequency division multiplexing multiplexed signals, and the spreading factor is determined. A transmission means for wirelessly transmitting to the wireless terminal device included in the L3 information;
A radio base station apparatus comprising: In radio terminal equipment using CDMA and FDMA as user multiplexing for L1 / L2 control channels in OFDM downlink
“Category 0” information including information on the number of subcarriers allocated per TTI, modulation scheme, and coding rate is wirelessly received from the radio base station apparatus together with multiplexed signals of code division multiplexing and frequency division multiplexing, and the spreading factor is Receiving means for wirelessly receiving the included L3 information from the wireless base station device;
Frequency division number calculating means for calculating a frequency division number from information included in the “Category 0” information, a spreading factor included in the L3 information, and a predetermined number of transmission bits per user;
Separating means for performing despreading according to a spreading factor included in the L3 information in each frequency region according to the calculated frequency division number for the multiplexed signal;
Obtaining means for obtaining control information addressed to the device from the despread demodulated data;
A wireless terminal device comprising: In a radio base station apparatus that uses CDMA and FDMA as user multiplexing for L1 / L2 control channels in the OFDM downlink,
Multiplexing means for performing code division multiplexing according to spreading factor and frequency division multiplexing according to the number of frequency divisions for each user's control information;
Information on the number of subcarriers allocated per TTI, modulation scheme, and coding rate is included in “Category 0” information and wirelessly transmitted to the radio terminal apparatus together with the code division multiplexed and frequency division multiplexed signals. Transmitting means for wirelessly transmitting to the wireless terminal device including L3 information,
A radio base station apparatus comprising: In radio terminal equipment using CDMA and FDMA as user multiplexing for L1 / L2 control channels in OFDM downlink
Receives “Category 0” information including information on the number of subcarriers allocated per TTI, modulation method, and coding rate from the radio base station apparatus together with the multiplexed signals of code division multiplexing and frequency division multiplexing. Receiving means for wirelessly receiving L3 information including the radio base station apparatus;
A spreading factor calculating means for calculating a spreading factor from the information included in the “Category 0” information, the frequency division number included in the L3 information, and a predetermined number of transmission bits per user;
Separating means for performing despreading according to the calculated spreading factor in each frequency domain according to the frequency division number included in the L3 information for the multiplexed signal;
Obtaining means for obtaining control information addressed to the device from the despread demodulated data;
A wireless terminal device comprising:   The radio base according to claim 7, 9 or 11, wherein the transmission means delays the timing of transmitting "Category 0" information by a time required for demodulation of L3 information in the radio terminal apparatus. Station equipment.

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