JP2006319715A - Communication terminal device, base station device, and ack/nack information transmission method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable to flexibly cope with traffic change, and also to aim at reduction of the power consumption for transmission and reception of ACK/NACK information, and reduction of hardware size. <P>SOLUTION: A control unit 155 sets up a spreading code used for despreading processing based on a signal which shows a spreading code and a process of ACK/NACK information which a base station device 200 assigns, in addition to the timing of despreading processing. A despreader 156 carries out despreading processing of the received signal of ACK information or NACK information by using a spreading code set up by the control unit 155, according to the timing set up by the control unit 155. A demodulator 157 demodulates an output signal of the despreader 156. An ACK/NACK judgment 158 judges whether the output signal of the demodulator 157 is ACK information, or it is NACK information. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a communication terminal apparatus, a base station apparatus, and an ACK / NACK information transmission method for performing wireless communication to which H-ARQ (Hybrid-Automatic ReQuest) is applied in an HSUPA (High Speed Uplink Packet Access) scheme. .

  In H-ARQ in HSUPA, the base station apparatus can receive ACK (Acknowledge) information for data transmitted from a communication terminal apparatus, and NACK (Non -Acknowledge) information is transmitted to the communication terminal device. In H-ARQ, there is a method in which either ACK information or NACK information is not transmitted.

Here, the base station apparatus multiplies the ACK information or NACK information by a predetermined spreading code and transmits it to the communication terminal apparatus. This spreading code allocation method for downlink ACK / NACK transmission is related to the scheduling method for uplink transmission of HSUPA, and the following methods are being studied.
(1) One communication terminal device group consisting of one communication terminal device or a plurality of communication terminal devices is assigned to one code.
(2) A communication terminal apparatus group is assigned to a code group composed of a plurality of codes (number of codes m).

Among them, the method (1) has a problem that it is difficult to flexibly cope with traffic fluctuations between communication terminal devices because one communication terminal device is fixedly assigned to a certain code. . That is, when the traffic of only a communication terminal device using a certain code is high and the traffic of a communication terminal device using another code is low, the code is assigned to the communication terminal device with high traffic even though the other codes are free. Cannot be assigned. On the other hand, the method (2) can flexibly cope with traffic fluctuations.
TSG RAN WG1 # 37 Tdoc # R1-040455

  However, in the conventional method (2), the code group is simply assigned to the communication terminal device group. Therefore, in each communication terminal device, the ACK / NACK information addressed to itself is transmitted in which code group. However, it is necessary to always despread all the codes (number of codes m) in the corresponding code group, resulting in a problem that current consumption increases and hardware scale increases.

  The present invention has been made in view of the above points, and when performing wireless communication to which H-ARQ is applied by the HSUPA method, it is possible to flexibly cope with traffic fluctuations and to provide ACK / NACK information. It is an object of the present invention to provide a communication terminal apparatus, a base station apparatus, and an ACK / NACK information transmission method that can reduce power consumption for reception and hardware scale.

  In order to achieve the above object, a communication terminal apparatus according to the present invention uses a spreading code and a despreading used for a despreading process based on a signal indicating a spreading code and process of ACK / NACK information assigned by a base station apparatus of a communication partner Control means for setting processing timing, despreading means for despreading a received signal of ACK information or NACK information using a spreading code set by the control means at a timing set by the control means, and the despreading The demodulating means for demodulating the output signal of the means and the ACK / NACK determining means for determining whether the output signal of the demodulating means is ACK information or NACK information.

  The base station apparatus of the present invention includes a control unit that allocates a spreading code and process of ACK / NACK information, an error detection unit that detects whether or not there is an error in data transmitted from a communication terminal device of a communication partner, A modulation unit that modulates ACK information or NACK information based on the detection result of the error detection unit, and a spreading code set by the control unit at a timing set by the control unit, spreads the output signal of the modulation unit It adopts a configuration comprising spreading means, and transmitting means for sending information indicating the assignment result of the control means and an output signal of the spreading means to the communication terminal device.

  The ACK / NACK information transmission method of the present invention includes a step of assigning a spreading code and process of ACK / NACK information, a step of sending information indicating the assignment result to a communication terminal device of a communication partner, and a transmission from the communication terminal device. Detecting whether or not there is an error in the received data, modulating ACK information or NACK information based on the error detection result, and using the set spreading code at the set timing A method of spreading the ACK information or NACK information, and transmitting the spread ACK information or NACK information to the communication terminal device.

  According to the present invention, when performing wireless communication applying H-ARQ in the HSUPA scheme, it is possible to flexibly cope with traffic fluctuations and to reduce power consumption for receiving ACK / NACK information. Reduction of hardware scale can be achieved.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of a communication terminal apparatus according to an embodiment of the present invention. In communication terminal apparatus 100 of FIG. 1, modulation section 101 modulates a transmission request signal that is a signal for requesting the base station apparatus of the communication counterpart to transmit data in HSUPA, and outputs the modulated signal to spreading section 102. The spreading unit 102 spreads the output signal of the modulation unit 101 and outputs it to the transmission radio unit 106.

  The transmission data selection unit 103 selects new data at the start of data transmission and when an ACK is received, and selects retransmission data when a NACK is received. Then, transmission data selection section 103 outputs the selected data to modulation section 104. Modulation section 104 modulates the data output from transmission data selection section 103 and outputs the result to spreading section 105. Spreading section 105 spreads the output signal of modulating section 104 and outputs it to transmitting radio section 106. Transmitting radio section 106 converts the baseband signal output from spreading section 102 or spreading section 105 into a radio frequency signal and outputs the signal to duplexer 107.

  The duplexer 107 wirelessly transmits the signal output from the transmission wireless unit 106 from the antenna 108. Further, duplexer 107 outputs a signal received by antenna 108 to reception radio section 151.

  Reception radio section 151 converts the radio frequency reception signal output from duplexer 107 into a baseband signal, and outputs the baseband signal to despreading section 152 or despreading section 156. Despreading section 152 despreads the output signal of reception radio section 151 and outputs the result to demodulation section 153. Demodulation section 153 demodulates the output signal of despreading section 152 and outputs it to transmission permission signal extraction section 154. Transmission permission signal extraction section 154 extracts a transmission permission signal from the output signal of demodulation section 153. The transmission permission signal includes information indicating permission of data transmission in HSUPA and information indicating the ACK / NACK spreading code and process number assigned by the base station apparatus (hereinafter referred to as “assignment information”). . The transmission permission signal extraction unit 154 outputs information indicating transmission permission to the transmission data selection unit 103 and outputs allocation information to the control unit 155. In this specification, “process” means a communication unit for a predetermined time, and the maximum value is equal to the maximum number of simultaneous activations of the H-ARQ process.

  The control unit 155 sets the spreading code used for the despreading process and the timing of the despreading process based on the ACK / NACK spreading code and process of the allocation information, and instructs the despreading unit 156. Despreading section 156 despreads the output signal of reception radio section 151 based on the instruction from control section 155 at the timing based on the allocation information, and outputs the result to demodulation section 157. Demodulation section 157 demodulates the output signal of despreading section 156 and outputs the demodulated signal to ACK / NACK determination section 158. The ACK / NACK determination unit 158 determines whether the output signal of the demodulation unit 157 is ACK information or NACK information, and outputs the determination result to the transmission data selection unit 103.

  FIG. 2 is a block diagram showing a configuration of the base station apparatus according to the present embodiment. In base station apparatus 200 of FIG. 2, duplexer 202 outputs a signal received by antenna 201 to reception radio section 203. The duplexer 202 wirelessly transmits the signal output from the transmission wireless unit 256 from the antenna 201.

  Reception radio section 203 converts the radio frequency reception signal output from duplexer 202 into a baseband signal, and outputs the baseband signal to despreading section 204 or despreading section 207. The despreading unit 204 despreads the output signal of the reception radio unit 203 and outputs it to the demodulation unit 205 when a data transmission request is made. Demodulation section 205 demodulates the output signal of despreading section 204 and outputs it to transmission request signal extraction section 206. The transmission request signal extraction unit 206 extracts a transmission request signal from the output signal of the demodulation unit 205 and outputs it to the control unit 251.

  Despreading section 207 despreads the output signal of reception radio section 203 and outputs it to demodulation section 208 at the time of data reception. Demodulation section 208 demodulates the output signal from despreading section 207 and outputs it to error detection section 209. The error detection unit 209 detects whether or not there is an error in the output signal of the demodulation unit 208. If no error is detected, the error detection unit 209 outputs received data to a subsequent process (not shown) and sends ACK information to the modulation unit 254. When an error is detected, NACK information is output to the modulation unit 254.

  The control unit 251 determines whether or not to permit transmission when there is a data transmission request in the HSUPA from the communication terminal apparatus, and allocates an ACK / NACK spreading code and process if transmission is permitted. Then, the control unit 251 outputs a transmission permission signal including information indicating permission of data transmission and allocation information indicating an ACK / NACK spreading code and a process to the modulation unit 252. In addition, the control unit 251 instructs the spreading unit 255 to use the spreading code used for spreading and the timing of the spreading process. Modulation section 252 modulates the transmission permission signal and outputs it to spreading section 253. The spreading unit 253 spreads the output signal of the modulation unit 252 and outputs the spread signal to the transmission radio unit 256.

  Modulation section 254 modulates ACK information or NACK information and outputs the result to spreading section 255. The spreading unit 255 spreads the output signal of the modulation unit 254 based on an instruction from the control unit 251 and outputs the spread signal to the transmission radio unit 256. Transmission radio section 256 converts the baseband signal output from spreading section 253 or spreading section 255 into a radio frequency signal and outputs the signal to duplexer 202.

  Next, the operation sequence of the base station apparatus and communication terminal apparatus according to the present embodiment will be described using the sequence diagram of FIG. In addition, in FIG. 3, the case where a communication terminal device (UE) transmits the data in HSUPA with respect to a base station apparatus (NodeB) using four processes is shown. In FIG. 3, the base station apparatus returns NACK when an error is detected in received data, and returns no information when no error is detected in received data.

  First, the communication terminal apparatus makes a transmission request to the base station apparatus (S301). Upon receiving the transmission request, the base station apparatus allocates an ACK / NACK spreading code and process (S302), permits transmission to the communication terminal apparatus, and transmits allocation information (S303).

  The communication terminal device that has received the transmission permission transmits data in HSUPA (S304). In FIG. 3, it is assumed that an error is detected in the data of processes # 1, # 2, and # 4 among the received data in the base station apparatus. In this case, the base station apparatus spreads the NACK information using the assigned spreading code, and transmits the spread NACK information in processes # 1, # 2, and # 4 (S305).

  The communication terminal apparatus uses the assigned spreading code to despread the signals received in the processes # 1, # 2, # 3, and # 4, and extracts NACK information. Then, the communication terminal apparatus retransmits data in processes # 1, # 2, and # 4 from which NACK information is extracted (S306).

  Next, the ACK / NACK information transmission method according to the present embodiment will be described in detail using a specific example of FIG.

  In FIG. 4, the NACK information is spread by any one of the three types of spreading codes # 1, # 2, and # 3, and the NACK is caused by any one of the four processes # 1, # 2, # 3, and # 4. Information shall be transmitted.

  First, as illustrated in FIG. 4A, the control unit 251 of the base station apparatus 200 assigns a spreading code and a process to each communication terminal apparatus. For example, focusing on user # 1, code # 2 is assigned to process # 1, code # 3 is assigned to process # 2, code # 3 is assigned to process # 3, and code # 1 is assigned to process # 4. Then, base station apparatus 200 transmits a transmission permission signal including allocation information to communication terminal apparatus 100. FIG. 4 shows the result of similar assignment to users # 2 and # 3. The assignment need not be made for all users simultaneously. You may make it allocate to a free process and a code | cord | chord at the time of the transmission request from each user. Further, the number of processes to be allocated may be adjusted as appropriate according to the content of the transmission request from each user.

  When receiving the transmission permission signal, communication terminal apparatus 100 transmits data to base station apparatus 200. When receiving data from communication terminal apparatus 100, base station apparatus 200 performs error detection, and spreading section 255 of base station apparatus 200 uses a spreading code assigned by control section 251 in the received data process in which an error is detected. Spread NACK information. For example, in FIG. 4B, if an error is detected in the data of the processes # 1, # 2, and # 4 from the user # 1, the code # 2 in the process # 1, the code # 3 in the process # 2, and the process In # 4, NACK information is spread by code # 1. In FIG. 4, it is assumed that the base station apparatus returns no information when no error is detected in the received data.

  The control unit 155 of the communication terminal apparatus 100 can recognize the spreading code multiplied by the NACK information transmitted in each process based on the allocation information, so that the despreading unit 156 is based on the control of the control unit 155. If despreading processing is performed using one spreading code for each process, NACK information can be extracted.

  Communication terminal apparatus 100 retransmits the data of the process that received the NACK information to base station apparatus 200. When the base station apparatus 200 receives the retransmitted data from the communication terminal apparatus 100, the base station apparatus 200 performs error detection, and the spreading unit 255 of the base station apparatus 200 assigns the control unit 251 again in the process of received data in which an error is detected. NACK information is spread with the spread code. For example, in FIG. 4C, if an error is detected again in the data of the process # 1 from the user # 1, the NACK information is spread again by the code # 2 in the process # 1.

  As described above, in the present embodiment, when performing wireless communication applying H-ARQ in the HSUPA scheme, the base station apparatus allocates the spreading code and process of ACK / NACK information when transmission is permitted, and the communication terminal apparatus It is determined that ACK / NACK information is always spread and transmitted using the assigned spreading code. Thereby, in the communication terminal device, if the despreading process is performed using one spreading code for each process, the NACK information can be extracted, so that it is possible to flexibly cope with traffic fluctuations, and Therefore, it is possible to reduce power consumption and hardware scale for receiving ACK / NACK information.

  In the present embodiment, the communication start time has been described. However, the present invention can also be applied during a handover. That is, at the time of a handover, a base station apparatus that newly becomes a communication partner can allocate a spreading code and a process of ACK / NACK information, and transmit the allocation information to the communication terminal apparatus.

(Embodiment 2)
In Embodiment 2, a case will be described in which the base station apparatus transmits only the transmission permission signal and the process number without transmitting information indicating the ACK / NACK spreading code to the communication terminal apparatus.

  The configuration of the base station apparatus of this embodiment is the same as that of FIG. 2 described in Embodiment 1, and control section 251 outputs a transmission permission signal consisting only of information indicating permission of data transmission to modulation section 252. This is different from the first embodiment.

  FIG. 5 is a block diagram showing a configuration of the communication terminal apparatus according to the present embodiment. In the communication terminal device 500 of FIG. 5, the same reference numerals are given to the same components as those of the communication terminal device 100 shown in FIG.

  5 is different from the control unit 155 of the communication terminal device 100 of FIG. 1 in the operation of the control unit 501. The communication terminal device 500 of FIG. Communication terminal apparatus 500 has despreading section 156 and demodulating section 157 for the number m of codes.

  In the present embodiment, communication terminal apparatus 500 cannot know in advance the spreading code to which ACK / NACK for the first data transmission is sent. For this reason, the control unit 501 controls the despreading units 156-1 to 156-m to despread all the corresponding code groups for the first ACK / NACK. Each of the despreading units 156-1 to 156-m despreads the output signal of the reception radio unit 151 based on an instruction from the control unit 501, and outputs the despreading unit to the corresponding demodulation units 157-1 to 157-m. Each demodulator 157-1 to 157-m demodulates the output signal of each despreader 156-1 to 156-m and outputs the demodulated signal to ACK / NACK determiner 158. The ACK / NACK determination unit 158 extracts ACK / NACK addressed to the own station from the output signals of the demodulation units 157-1 to 157-m, and determines whether the extracted information is ACK information or NACK information. The determination result is output to the transmission data selection unit 103 and the control unit 501.

  When the base station apparatus transmits ACK / NACK to the retransmission data, the spreading code and the process number are not changed. Therefore, the control unit 501 uses the spreading code used last time for the process in which the previous NACK information is detected. What is necessary is just to control each despreading part 156-1 to 156-m so that despreading may be carried out.

  Therefore, the communication terminal device 500 does not need to perform despreading and demodulation for the other (m−1) codes for the spreading code and the corresponding process to which ACK / NACK is sent from the second time onward, and thus reduces the current consumption. Can be reduced.

  In the present embodiment, the transmission permission signal, the process number, and the ACK / NACK spread code signal have been described separately. However, in the present invention, the transmission permission signal may be omitted and similarly implemented. The effect can be obtained. In this case, when one or both of the process number and the ACK / NACK spreading code assignment information is “invalid” or “transmission not permitted”, it can be realized by interpreting that transmission is not permitted.

  INDUSTRIAL APPLICABILITY The present invention is suitable for use in a communication terminal apparatus and base station apparatus that perform wireless communication using H-ARQ with the HSUPA method.

The block diagram which shows the structure of the communication terminal device which concerns on Embodiment 1 of this invention. The block diagram which shows the structure of the base station apparatus which concerns on Embodiment 1 of this invention. The sequence diagram which shows the operation | movement order of the base station apparatus and communication terminal device which concern on Embodiment 1 of this invention The figure for demonstrating the ACK / NACK information transmission method which concerns on Embodiment 1 of this invention. The block diagram which shows the structure of the communication terminal device which concerns on Embodiment 2 of this invention.

Explanation of symbols

100, 500 Communication terminal device 101, 104 Modulation unit 102, 105 Spreading unit 103 Transmission data selection unit 152, 156 Despreading unit 153, 157 Demodulation unit 154 Transmission permission signal extraction unit 155, 501 Control unit 158 ACK / NACK determination unit 200 Base station apparatus 204, 207 Despreading unit 205, 208 Demodulating unit 206 Transmission request signal extracting unit 209 Error detecting unit 251 Control unit 252, 254 Modulating unit 253, 255 Spreading unit

Claims (3)

Control means for setting the spreading code used for the despreading process and the timing of the despreading process based on the signal indicating the spreading code and process of the ACK / NACK information assigned by the base station apparatus of the communication partner;
Despreading means for despreading the received signal of ACK information or NACK information using the spreading code set by the control means at the timing set by the control means;
Demodulation means for demodulating the output signal of the despreading means;
ACK / NACK determination means for determining whether the output signal of the demodulation means is ACK information or NACK information;
A communication terminal device comprising: Control means for assigning spreading codes and processes of ACK / NACK information;
Error detection means for detecting whether or not there is an error in the data transmitted from the communication terminal device of the communication partner;
Modulation means for modulating ACK information or NACK information based on the detection result of the error detection means;
Spreading means for spreading the output signal of the modulation means using a spreading code set by the control means at a timing set by the control means;
Transmitting means for transmitting information indicating an assignment result of the control means and an output signal of the spreading means to the communication terminal device;
A base station apparatus comprising: Assigning a spreading code and process for ACK / NACK information;
Transmitting information indicating the allocation result to a communication terminal device of a communication partner;
Detecting whether there is an error in the data transmitted from the communication terminal device;
Modulating ACK information or NACK information based on the error detection result;
Spreading the modulated ACK information or NACK information using the set spreading code at the set timing;
Transmitting the spread ACK information or NACK information to the communication terminal device;
An ACK / NACK information transmission method comprising:

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