WO2005051012A1

WO2005051012A1 - Communication system, transmission device, reception device, and data communication method

Info

Publication number: WO2005051012A1
Application number: PCT/JP2003/014661
Authority: WO
Inventors: Noriyuki Fukui; Michiaki Takano; Kazuhito Niwano; Hideji Wakabayashi
Original assignee: Mitsubishi Denki Kabushiki Kaisha
Priority date: 2003-11-18
Filing date: 2003-11-18
Publication date: 2005-06-02
Also published as: AU2003280848A1

Abstract

A transmission device creates control information added by an error detection code for data transmission and creates control information including identification information for identifying a reception device and having no error detection code when transmission channel quality information is required. The transmission device selects one of plural common control channels and transmits control information created by the data creation step via the selected common control channel. A reception device decrypts control information on the common control channel. If the control information relates to data transmission, the error detection code of the control information is used to detect a control information error. If the control information relates to a transmission channel quality request, no error detection is performed and the detection result of the control information is used. When the quality information request is detected, the quality information is transmitted.

Description

Description Communication system, transmitting device, receiving device, and data communication method

Technical field

The present invention relates to a method for reporting the quality of a transmission channel between a transmitter and a receiver. The present invention is specifically applicable to a mobile telecommunications system that supports HSDPA. Background art

Recently, the High Speed Downlink Packet Access (HSDPA) function that extends the Universal Mobile Telecommunication System (UMTS) has been standardized within the framework of the 3GPP forum. This new feature enables high-speed access to packet services through a new transport channel called HS-DSCH (High Speed-Downlink Shared Channel). The physical channels on which the HS-DSCH is mapped are called High Speed Physical Downlink Shared Channels (HS-PDSCHs) and can be shared by users in the code domain as well as the time domain. It is. Users are assigned one or more channelization codes (ie, spreading codes) in the HS-DSCH as needed. Furthermore, the HS-DSCH channel is expected to be able to support various rates and channel conditions by supporting hybrid ARQ and using adaptive modulation and coding (AMC). . In addition, in HSDPA, each UE needs to have a CQI (Channel Quality Indicator, Channel Quality Indicator) at regular intervals to enable the base station to adapt the coding rate and / or modulation (method) to the transmission conditions. The base station tracks variations in the quality of the transmission channel and reports the transmission parameters accordingly. Evening (eg coding rate or modulation scheme) can be adapted. However, the quality of the transmission channel may fluctuate very rapidly, especially when the UE is moving at high speed or when radio wave shields appear. If the quality degrades during the two scheduled; ^ CQI reporting times, the base station will not be able to correct the transmission parameters to cope with poor transmission conditions, resulting in an increased packet error rate Therefore, the 3GPP Forum is currently examining whether it is necessary to report (onde, mand) CQI information based on a request from the base station in addition to regular CQI information reporting. DISCLOSURE OF THE INVENTION ''

An object of the present invention is to obtain a communication system and a communication method with good responsiveness with respect to CQI information when a receiving device transmits reception channel quality information on demand. In the data communication of the present invention, the transmitting device generates control information to which identification information for identifying the receiving device and an error detection code are added in the case of overnight transmission, and receives control information when requesting transmission channel quality information. It generates control information that includes identification information that identifies the device and has no error correction code. Then, one of the plurality of common control channels is selected, and the control information generated in the data generation step is transmitted via the selected common control channel. On the other hand, the receiving device receives a plurality of common control channels. In addition, the receiving device decodes the control information of the common control channel, and if the control information is control information related to data transfer, performs error detection of the control information using an error detection code included in the control information, and If the information is the quality requirement of the transmission channel, the detection result of the control information is used without error detection. If the reception processing unit detects a request for quality information, it sends the quality information.o Brief description of the drawing

FIG. 1 is a diagram schematically showing a configuration of HSDPA access.

FIG. 2 is a diagram schematically illustrating a process performed by a user device to receive data from a plurality of downlink shared channels. FIG. 3 is a diagram schematically showing a frame configuration of an HS-DPCCH channel.

FIG. 4 is a diagram illustrating a process for reporting channel quality information.

FIG. 5 is a diagram showing a process for reporting channel quality information.

FIG. 6 is a configuration diagram illustrating a communication system according to the first embodiment.

FIG. 7 is a diagram showing a time sequence for explaining CQI transmission according to the first embodiment.

FIG. 8 is a configuration diagram illustrating a communication system according to a second embodiment.

FIG. 9 is a diagram showing an evening sequence for explaining CQI transmission according to the second embodiment.

FIG. 10 is a flowchart illustrating a control signal transmission process according to the second embodiment. FIG. 11 is a flowchart illustrating a control signal receiving process according to the second embodiment.

FIG. 12 is a configuration diagram showing a first-part encoding apparatus according to the second embodiment.

FIG. 13 is a flowchart illustrating channel selection processing on the transmitting side according to the second embodiment.

FIG. 14 is a flowchart illustrating channel selection processing on the receiving side according to the second embodiment. ,

FIG. 15 is a time sequence illustrating channel monitoring in the second embodiment.

FIG. 16 is a diagram showing a process of CQI transmission in the second embodiment.

FIG. 17 is a diagram showing a process of CQI transmission in the second embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1.

Fig. 1 schematically shows the channels involved in HSDPA access. Basically, there are 15 HS-PDSCH channels for transmitting data from the base station (Node B) to various user equipments (UEs), and HS-SCCH (High Speed Shared Channel) for transmitting related downlink signaling. Control CHannels, four channels called high-speed shared control channels, and one application called HS-DPCCH (High Speed Dedicated Physical Control CHannel), which can transmit feedback information to base stations. A link channel is provided. For various UEs The data subframes can be code multiplexed and time multiplexed over the HS-EDSCH channel. More specifically, for a given TTI (Transmission Time Interval), the HS-PDSCH channel can accommodate from 1 to 15 users at the same time. A more complete description of shared channels in HSDPA can be found in 3GPP Technical Report TR 25.858 v.5.0.0 (available from the website www.3gpp.org), which is hereby incorporated by reference. Fig. 2 shows the process of receiving data from a base station through HSDPA access. The above HS-SCCH channels, numbered 0-3, are shown in the upper part of the figure, while the HS-PDSCH channels, numbered 0-: 14, and the HS-DPCCH channel are shown below. Is displayed. All channels receive the same time division as the so-called TTI (Time Transmission Interval), and each TTI corresponds to three time slots in UMTS-FDD (UMTS Frequency Division Duplex). On the other hand, a radio frame is divided into five subframes, and one subframe is transmitted during one TTI. The subframe transmitted by the HS-SCCH channel is called a signaling subframe, and the subframe transmitted by the HS-PDSCH channel is called a data subframe. For example, reference numerals 210 to 260 indicate signaling subframes, and 211 to 261 indicate data subframes.

The UE monitors the HS-SCCH channel, with its UE ID (UE IDentifier _s UE identifier), signaling subframe to check whether they are assigned to the user. If so, the UE shall determine from the content of the signaling subframe Is determined (from HS-FDSCH # 0 to HS-PDSCH # 14). For example, the signaling subframe 220 indicates that HS-PDSCH # 1 is transmitting the data subframe 221 of the user.

The UE checks whether there is an error in the user data included in the data subframe. If there are no errors, an acknowledgment indication ACK is sent to the base station over the HS-DPCCH; otherwise, a negative acknowledgment NACK is also returned, and the base station retransmits the user data at a later time. In order to allow the base station to adapt the coding rate and / or modulation scheme to the transmission conditions, each UE has a CQI (Channel Quality Indicator, hereinafter referred to as CQI information) at regular intervals. ), Which is a parameter that represents the quality of the transmission channel. For example, if the transmission quality is low, the base station can select a lower coding rate and / or a lower modulation scheme; conversely, if the transmission quality is high, the base station can select a higher coding rate It is possible to select a modulation rate and / or a higher modulation scheme. In practice, the CQI information is encoded as binary words and transmitted to the base station via the HS-DPCCH channel. FIG. 3 schematically shows the frame structure of the HS-DPCCH channel. The total duration of this frame is T f = 10 ms and is divided into five cells, such as TTI 310-350, each cell consisting of three time slots (of duration T s). A subframe is transmitted in one frame and may include ACK / NACK information and / or CQI information. Note that, The ACK / NACK information and CQI information are transmitted independently of each other, and the subframe may contain both information, none of them, or only one of them. More strictly, ACK / NACK information is transmitted each time the UE receives a data subframe from the base station through HSPDA access. On the other hand, the CQI information is transmitted at scheduled and periodically distributed transmission times. The method of determining the transmission time is described in detail in 3GPP specification TS 25.214 v5.6.0, paragraph 6A.1.2 (available from the website www.3gpp.org). The reporting period T r that separates two consecutive reporting times is reported to the UE by the upper protocol layer and has various values expressed as the number of subframes: 1, 2, 4, 5, 10, 20, 40 Or 80 subframes. FIG. 4 schematically shows a time chart of reporting CQI information. UE is at time t. , Tt _2, etc., and estimate the quality of the transmission channel, and report these estimates as CQ reports at times t ′ ₀ , t,, t ′ ₂ distributed at regular intervals Tr. The CQI is usually created from the measurement results of the received pilot symbols transmitted by the base station via the primary CPIQH (Common Pilot CHannel) or the secondary CPICH. The transmission of pilot symbols is always performed, and the dotted arrows 410, 420, and 430 in the figure indicate measurement timing. After the channel quality is estimated, the UE sends the corresponding CQI information at the next scheduled report time. Transmission of CQI information through the HS-DPCCH channel is indicated by arrows 411, 421, and 431 in the figure. The periodic transmission of the CQI allows the base station to track variations in the quality of the transmission channel and respond accordingly to the transmission parameters (eg, coding rate or modulation scheme). ) Can be adapted. However, as mentioned above, the quality of the transmission channel can fluctuate very rapidly, especially when the UE is moving at high speed or when radio wave shields appear. If the quality drops between the two scheduled CQI reporting times, the base station will not be able to correct the transmission parameters to cope with poor transmission conditions, resulting in an increased packet error rate Will be. To mitigate this effect, shorter reporting periods may be employed as a possible countermeasure, but at the cost of more frequent transmission of CQI information, the level of interference on the uplink will be significantly increased. Conversely, a similar situation occurs when the quality of the transmission channel improves between two scheduled CQI reporting times. In such a situation, the base station cannot benefit from the newly improved transmission conditions until the next report is received. Therefore, in addition to the regular CQI report, it was considered that the CQI report is sent from the receiving side in response to a request from the sending side. Figure 5 shows a time chart of the CQI report executed on demand. The transmitting side transmits a CQI request signal 413 using the HS-SCCH when determining that the CQI needs to be updated in addition to the periodic report of the CQI. Upon detecting the CQI request 413, the receiver estimates the quality of the transmission channel from the reception result of the received pilot signal 412, and returns a CQI report 414 using the HS-DPCCH. By performing on-demand CQI reporting in this way, the problem of regular CQI reporting can be solved, and an increase in the packet error rate can be suppressed. FIG. 6 shows a communication system that performs on-demand CQI reporting. Here, the communication system shown in FIG. 6 is applicable not only to the above-mentioned UMTS communication system but also to other communication systems. Transmitter 1 receives It has a unit 11, a data generation unit 12, and a transmission unit 13. The receiving unit 11 receives the response signal from the receiver 2, performs demodulation processing, and also receives data other than the control signal from the receiver 2. The data generator 12 generates a data and a control signal to be transmitted to the receiver 2 based on the response signal demodulated by the receiver 11. Here, the response signal is a signal indicating whether the transmission has succeeded / failed. If the transmission has failed, the data generating unit 12 performs a process of retransmitting the same data. The transmitting unit 13 modulates the data and control signal generated by the data generating unit 12 and transmits the modulated signal and the control signal to the receiver. On the other hand, the receiver 2 includes a reception unit 21, a reception processing unit 22, a channel quality measurement unit 23, and a transmission unit 24. The receiving unit 21 receives the demodulated data and the control signal transmitted by the transmitter 1, and demodulates the data. The reception processing unit 22 performs an error detection process overnight based on the control signal demodulated by the reception unit 21, and transmits a signal indicating normal reception to the transmission unit 24 when the reception is normal. If the destination is an external device, a process for transferring the data to the external device is performed. On the other hand, if the received data contains an error or the data cannot be received, the reception processing unit 22 transmits to the transmission unit 24 a message indicating that the reception has failed. In addition, the reception processing unit 22 has a detection unit that monitors identification information (eg, UE ID) of a plurality of common control channels and detects control information addressed to itself from control data of the common control channels. Further, the channel quality measuring section 23 performs the process of estimating the channel quality as described above based on the pilot symbol in the received signal. The quality information measured by the channel quality measurement unit 23 is transmitted from the transmission unit 24 periodically and based on the reception timing of the CQI request signal included in the control signal. The transmitting unit 24 performs a process of modulating the data and control signal output from the data generating unit (not shown) and transmitting the modulated signal to the transmitter 1. Next, on-demand CQI transmission by the communication system according to the first embodiment will be described in detail. FIG. 7 is a timing chart showing CQI transmission timing. In this example, the communication system has n (n is an integer of 1 or more) control channels, and each control channel is transmitted with a data destination transmitted by the data channel and its error detection code. You.

• Data transmission and reception

First, a normal data transmission operation will be described. The data generator 12 of the transmitter 1 generates data to be transmitted, and sends the destination information and its ^{error_detection} code to the transmitter 13. The transmitting unit 13 selects one of n (n is an integer of 1 or more) control channels and transmits the received destination information of the received data. As shown in FIG. 7, the transmitted destination information includes a first part (Part 1) storing the destination information and a second part (Part 2) storing the error detection code. Transmitted as a frame.

In the receiver 2, the receiving unit 21 receives the destination information 82, and the receiving processing unit 22 detects whether the next data 83 is assigned to its own receiving device based on the destination information, and The destination information in the first part is checked for errors based on the error detection code in the part. On the other hand, receiver 2 starts receiving data 83 based on the first part, but if it determines from the final determination using the error detection code that control signal 82 is not addressed to its own station, Discards the received 83.

The error detection performed by the receiver 2 may use any known technique. For example, error detection of a CRC (Cyclic Redundancy Check) method can be used. • CQI transmission operation

Next, the on-demand CQI transmission operation will be described. When the transmitter determines that the CQI needs to be updated, the data generation unit 12 generates destination information that specifies a receiver that requires a CQI update. The CQI transmission request generated at this time is formed from a bit pattern different from that indicating normal data transmission. Also, the data generation unit 1'2 omits generation of the error detection code. The transmitting unit 13 having received the destination information from the data generating unit 12 modulates the destination information and transmits the modulated destination information to the receiver 2 as a CQI request 84. Here, since the error detection code is not added to the CQI request 84, the transmitting unit 13 transmits a frame in which the second part has no significant data (the second part is omitted). .

The receiving unit 21 of the receiver 2 receives the CQI request 84, demodulates it, and transmits it to the reception processing unit 22. After receiving the first part of the received CQI request 84, the reception processing unit 22 identifies whether the signal of the first part is related to data transfer or CQI request, , Determine whether the destination is your own receiver. When determining that the received signal is a CQI request, the reception processing unit 22 transmits an instruction signal to the channel quality measurement unit 23, and requests creation of a CQI. The channel quality measurement unit 23 estimates the channel quality from the reception state of the pilot signal, and transmits a CQI according to the quality to the transmission unit 24. Transmitter 24 modulates the received CQI and transmits it to transmitter 1 via the response channel. Transmitter 1 receives the CQI and transmits the received CQI.

(As described above, in the first embodiment, the process of switching the format of the frame transmitted from the transmitter 1 between the case of transmitting the data and the case of transmitting the CQI information is described. And the receiving process performed by receiver 2 Is being processed. Therefore, as shown in Fig. 7, the timing of transmitting the CQI can be made earlier. (The transmission timing of data 83 and CQI shown in Fig. 7 is an example, and the performance and It depends on the communication method and other conditions.) That is, at the time of CQI transmission, an error check is not performed as in a data reception process in which a malfunction is not allowed, and an operation of transmitting a CQI before error check (without error check) can be started. For example, assuming that error detection is performed at the time of CQI transmission, the reception time of CQI request 84 of the control channel is longer by the reception of the second part. Then, if error detection and transmission processing are started after the reception of the second part, the timing will be late, as shown at t2 in FIG. In contrast, according to the communication method of the first embodiment, the processing can be started without waiting for the reception of the second part (error detection code) of the frame, so that the CQI transmission operation is started after error detection is performed. The CQI can be transmitted earlier in the evening than in the case where it is performed. By not transmitting the second part of the frame, the amount of interference with other channels can be reduced, and the communication quality of the entire communication system can be improved. Embodiment 2.

Next, an embodiment in which the present invention is applied to a UMTS will be described. Further, the communication system according to the present embodiment has a suitable selection function of a plurality of control channels as an additional function.

FIG. 8 shows a communication system according to the second embodiment. In FIG. 8, reception processing section 14 decodes the signal demodulated by reception section 11 and extracts CQI information and ACK / NACK signals from the decoded signal. This is a device that transfers the data from the end 2 to devices inside and outside the base station, and any known device developed for UMTS can be applied. The transmission control unit 15 is a control device that controls various transmission devices such as the transmission unit 13 and the data generation unit 19, and has a transport format determination unit 16 and a transmission channel determination unit 17. The transport format determination unit 16 adaptively determines the data format used for data transmission based on the capabilities of each terminal, the amount of data stored for each terminal, and communication conditions such as CQI. The transmission channel determination unit 17 has a function of selecting a channel for transmitting control information from a plurality of HS-SCCHs. The data generation unit 19 has a function of reading data from the buffer 18, performing CRC addition, data encoding, interleaving, and the like, mapping the data to an appropriate channel, and sending the data to the transmission unit 13. The transmission control unit 15 has a function of executing hybrid ARQ in HSDPA. The details are described in 3GPP Technical Specification 3G TS 25.212 and the like, and the encoding and modulation methods of HSDPA are described in Chapter 5 of 3GPP Technical Report TR25.858 V5.0.0. On the other hand, the reception control unit 25 of the terminal 2 receives from the reception processing unit 22 the control signals such as the overnight format and CQI request and the ACK / NACK signal indicating the success or failure of the reception, and based on these signals, the reception processing unit It is a device that controls the 22 reception operation and the CQI creation operation of the CQI creation unit. Further, the reception control unit 25 has a reception channel determination unit 26, and performs control for selecting the HS-SCCH monitored by the reception unit and the reception processing unit 22 by the reception channel determination unit 26. The channel quality measurement unit 23a estimates channel quality from reception characteristics such as a reception pilot sequence such as CPICH. The channel quality measurement may be performed at all times or specified based on the instruction of the reception control unit 25. May be executed at the timing of transmitting the CQI, in particular. The data generation unit 28 is a device that encodes transmission data, and not only a version called UMTS Release 99, but also high-speed communication using uplink enhancement currently under consideration at 3GPP. It is also possible to use a transmission data generation unit corresponding to future transmission processing, such as a version of the transmission data. Next, the operation of this communication system will be described with reference to FIG. FIG. 9 shows a time chart of the CQI reporting process in this embodiment.

• Data transmission / reception operation

First, in the data transmission / reception operation, the transmission unit 13 transmits control information including the format information determined by the transport format determination unit 16. At this time, transmitting section 13 transmits control information from a plurality of HS-SCCHs using the channel selected by transmission channel determining section 17. This control information is, as shown in FIG. 9, a subframe 92 having a first part (Part i) for identifying the terminal 2 and a second part (Part 2) including the CRC code and the format information. Sent (details will be described later). FIG. 10 shows HS-SCCH data generation processing by the data generation unit 19. First, the data generator 19 checks whether the control information to be transmitted is a data transfer or a CQI request (step S1). In the case of data transfer, CRC is calculated for the first and second parts, and the CRC is added to the second part. Then, the first part is encoded using the UE ID (step S3), and the second part is also encoded (step S4). Finally, the data generator 19 outputs the encoded first and second parts to the transmitter 13 (step S6). Further, following the transmission of the control information, the transmitting unit 13 The evening transmission section 19 transmits the evening generated by using the HS-DSCH.

The reception unit 21 of the terminal 2 demodulates the subframe 92 and transmits the demodulated data to the reception processing unit 22. The reception processing unit 22 decodes the demodulated data by a decoding process or the like corresponding to the encoding process or the like of the base station 1, and extracts control information. FIG. 11 shows a reception process by the reception processing unit 22 _(the reception processing unit 22 decodes the demodulated first part with the UE ID. Then, it is determined whether the control signal is a control signal addressed to the own station. (Step S11) If the address is not addressed to the own station, the channel information is discarded.If the address is addressed to the own station, the signal processing unit 22 checks the type of the control signal (Step S12), and If the pattern matches the determined pattern and it is determined that the packet is related to data transfer, preparation for HS-DSCH reception is started (step S13). Then, it performs reception and decoding, and performs error detection on the first part and the second part using the CRC code included in the second part (step S15). The data is output to the transmission data generation unit 28 (step S16). Based on the control information, the receiving unit 21 and the receiving processing unit 22 are controlled to receive the HS-DSCH data.

• CQI transmission operation

As described above, HS-SCCH is originally a channel for transmitting control information for receiving HS-DSCH, but currently 3GPP can also use this HS-SCCH for on-demand CQI requests. We are considering whether to do so. .

The control information in FIG. 9 is composed of the following data.

Transport-format and Resource related Information (TFRI) -Channelization-code set: 7 oits

-Modulation scheme: 1 bit

-Transport-block size: 6 bits

Hybrid- ARG-related Information (HARQ information)

-Hybrid-ARQ process number: 3 bits-Redundancy version: 3 bits

-New Day Data (New-data indicator): 1 bit

(Refer to 3G TR25.858 Chapter 8.) Of these data, the first part consists of the channelization code set and modulation scheme, totaling 8 bits, with the remaining 13 bits in the second part. Is stored. CRC is calculated for each of the first part and the second part, and added after the above-mentioned 13 bits of the second part.

Here, since the channelization code set has an unused (reserved) bit pattern, this unused bit pattern is set in section 6.1.1.1 of 3GPP TR 25.899 V0.2.2. It has been proposed to allocate (eg, "111 0000") for CQI reporting requests (also called Fast CQI requests). When the transmission control unit 15 issues a CQI request, the data generation unit 19 of the second embodiment executes a process of adding a CRC to the channelization code set as specified in 3G TR25.858 Chapter 8. First, a process of omitting the second part of the HS-SCCH subframe is performed (step S5 in FIG. 10). Then, as shown in FIG. 9, the sub-frame 93 of the HS-SCCH is transmitted with the second part omitted. On the other hand, the reception processing unit 22 of the terminal 2 decodes the channelization code set and checks whether this channelization code set is a CQI request directed to the own terminal. That is, it checks whether the decryption result is a predetermined specific pattern. If the request is a CQI request, the reception processing unit 22 notifies that a CQI request has been made, and the reception control unit 25 instructs the CQI creation unit 27 to create a CQI (step S17 in FIG. 11). The CQI creation unit 27 creates a CQI according to the channel quality estimated by the channel quality measurement unit 23a, and outputs the created CQI to the transmission data generation unit 28. The transmitting data generator 28 encodes the received CQI and transmits it to the base station 1 via the transmitting unit 24. -Here, it should be noted that unlike the data reception, the reception processing unit 22 can start the CQI transmission operation without performing error detection by CRC. By this operation, similarly to Embodiment 1 described above, the timing of CQI transmission can be further advanced.

• Address recognition processing

In transmitting CQI, terminal 2 must determine whether the CQI request is transmitted to its own station. Therefore, reception processing section 22 of the present embodiment determines whether or not the control signal is a CQI request for its own station by using the same method as in HS-DSCH data communication. FIG. 12 shows a method in which the data generation unit 19 of the base station 1 encodes the first part using the terminal-specific identifier, that is, the UE ID. The details are as described in 3G TR section 8.1.2 and 3G TS25.212.But briefly, it is necessary to apply rate matching by applying the first part to 1/2 convolutional coding processing. Is converted to coded data of specified bits To do. On the other hand, the UE ID is block-coded by the block coding unit, and a predetermined bit is made redundant to create a scramble sequence of the predetermined bit. By performing an exclusive OR operation on the two data obtained as described above, a code obtained by scrambling the first part with the UE ID is obtained. (On the other hand, the reception processing unit 22 of the terminal 2 determines its own terminal. The first part of the received subframe is descrambled by using the UE ID of the UE, and the descrambling result is evaluated for reliability by the behaviour-algorithm algorithm. If a CQI request is detected after the determination, a signal notifying that the CQI request has been received is output to the reception control unit 25.

-Channel selection processing

Next, a process of selecting the HS-SCCH will be described.

FIG. 13 is a flowchart showing a channel selection process in transmission channel determination section 17 of base station 1. First, the transmission channel determination unit 17 checks the type of control information (step S30). If the control information indicates the overnight transfer, it is detected whether the data transfer is ongoing (step S31). If the channel is being continued, the currently selected channel is reselected, and an instruction is given to the data generating unit 17 (step S32). If the transmission is not ongoing, the transmission channel determination unit 17 selects a channel that can transmit the control message, that is, a channel with a margin, and outputs the selection result to the data generation unit 19 (step S33).

On the other hand, if the control information to be transmitted is a CQI request, it is checked whether data transfer is ongoing (step S34). If so, the same channel as the data transfer is selected. Then, the selection result is output to the data generator 19 (step S35). If the transmission has not been continued, the transmission channel determination unit 17 selects a new channel as in step S33. Then, a signal is output to the data generator 19 (step S36).

By performing the above processing, the reliability of the CQI request can be improved even when the CRC is not attached to the control information. In other words, since the CQI request is sent to the same shared control channel during the data transfer, the probability that the control information sent to the same channel is the information sent to the terminal 2 is higher than that of the other shared control channels. Reliability can be improved compared to sending a CQI request by selecting a shared control channel randomly. Terminal 2 also has the advantage that the processing load can be reduced because it is sufficient to monitor one shared control channel during data transfer (during reception). Next, the selection process of the reception channel determination unit 26 of the terminal 2 will be described with reference to FIG. First, the reception channel determination unit 26 checks whether the control information decoded by the reception processing unit 22 is related to overnight transfer or a CQI request (step S40). If the data transfer is to be performed, it is checked whether the data transfer is completed by the current reception (step S41). That is, when the reception processing unit 22 receives the HS-SCCH that has been received at the next subframe timing and determines that it is not addressed to its own station, the reception processing unit 22 determines whether or not the data transfer has ended at the same time. Judgment that the transfer has ended overnight. Then, in the next subframe, all HS-SCCHs are monitored. If the processing has been completed, the reception channel determination unit 26 selects all the channels as monitoring targets and outputs the selection result to the reception processing unit 22 and / or the reception unit 21 (step S42). If not, the current channel is reselected as a monitoring target, and the selection result is output to the reception processing unit 22 and / or the reception unit 21 (step S43). As described above, in the HSDPA, after the data transfer is started, the terminal 2 only needs to monitor a specific shared control channel. This reduces the burden of monitoring the shared control channel. Can. When the receiving channel determining unit 26 determines that the control information relates to the CQI request in step S40, the receiving channel determining unit 26 selects all channels as monitoring targets (step S44). If a CQI request is received, all channels are monitored because the CQI request does not have a CRC code attached, and there is a possibility that the CQI request is erroneously detected. Because. In the communication system according to this embodiment, error detection based on the second part of the HS-SCCH is not performed, so that it is possible to quickly respond to the CQI request. Here, even if a CQI request is erroneously detected, since all the shared control channels are monitored after the CQI request, it is possible to prevent control information transmitted to other shared control channels from being overlooked. FIG. 15 is a time chart showing the monitoring status of HS-SCCH by terminal 2. A hatched portion 133 indicates a monitoring target (range) by the reception processing unit 22. As shown in FIG. 15, after receiving control information 131 on data transfer, terminal 2 narrows the monitoring target to a specific channel, and after receiving the CQI request, terminal 2 selects the monitoring target for all channels. Expanding. · NACK based I Activity based CQI transmission

The above-described on-demand CQI transmission can be combined with CQI transmission based on the activity of a NACK signal or a response signal. The following describes CQI transmission based on NACK.

Normally, terminal 2 can estimate the quality of the transmission channel from the received pilot symbols (or known sequence) transmitted by base station 1. it can. FIG. 16 shows an example of CQI transmission based on NACK. The times at which the terminal 2 estimates the quality of the transmission channel are indicated by to, and the scheduled times at which these estimates are reported to the base station are indicated by t′o, tΊ. For example, the scheduled times are regularly distributed over a period of time with a period Tr. Pilot symbol measurements are represented in the figure by dotted arrows 510 and 530, and transmission of the CQI report is represented by plain arrows 511 and 531. Here, it is assumed that the quality of the transmission channel degrades after the scheduled reporting time t'o. The base station will remain unaware of the worsening transmission conditions until time t. Furthermore, if the quality of the transmission channel degrades and then recovers to its original value before t'i, e.g. if the CQI suffers a periodic degradation due to a high fusing rate, these fluctuations will be transmitted to the base station. According to the CQI transmission based on this NACK, terminal 2 reports information indicating the quality of the transmission channel to the transmitter when negative acknowledgment information (NACK) is to be transmitted. I do. In such a case, the CQI information can be transmitted in the same subframe together with the negative acknowledgment information, as shown in Fig. 3. Error detection in the received data overnight subframe (and therefore transmission of NACK after that) Is actually a clue that the transmission conditions have deteriorated. The situation is shown in FIG. 16, where, at time t, terminal 2 detects an error in the data subframe and consequently sends negative acknowledgment information at time t ′. The bold and dotted arrows with reference number 520 represent data subframe transmission and pilot symbol (or known sequence) measurements, respectively, while the plain arrow 521 indicates that a NACK is transmitted with CQI information. Represent. It should be noted that the estimation of the channel quality itself can be triggered by the detection of erroneous subframes. Yes, or alternatively, the channel quality can be systematically estimated. In both cases, the resulting CQI information can only be transmitted if the subframe is found to be erroneous.

Another advantage is that longer reporting periods T r can be used. Indeed, high reporting rates are not required, as degradation in transmission conditions is reported to the transmitter without delay, and as a result, the level of interference on the uplink can be kept low. FIG. 17 shows a time chart of another reporting process of CQI transmission based on NACK. Again, pilot symbol measurements are represented by dotted arrows, e.g., 610, 630, 650; overnight transmissions are represented by bold arrows, e.g., 620, 640; transmission of feedback information is represented by ordinary arrows, For example, they are represented by 611, 621, 631, 641, 651. According to this example, schedule the CQI information time _{t 'Q, t Ί, t} ' in addition to systematically reporting a _2, etc., the quality of the transmission channel is improved by at least a predetermined threshold value (△) When the ACK is transmitted, the CQI information is also reported at the time when the ACK is transmitted, for example, at time t "'as in the first embodiment. More precisely, the time when the acknowledgment information is returned to the transmitter At (eg, at time t '"), the transmission channel quality estimated immediately before (here, at time t") is lower than the quality reported immediately before (ie, the quality estimated at time). If so, the new value of CQI is transmitted with the ACK information, preferably in the same subframe as shown in FIG. According to the modification, the CQI information is transmitted only after the quality improvement has been observed over a predetermined minimum number of consecutive ACKs, thereby avoiding taking into account a spike in apparent quality.

The CQI transmission based on the activity returns the CQI not only when the NACK is returned but also when the ACK is returned, and the CQI transmission based on the activity may be performed on demand as described above. It may be used together with CQI transmission by the command.

Further, the channel selection processing of the second embodiment can be applied to the communication system of the first embodiment. Also, the flowcharts described in the embodiments can be realized by using a dedicated integrated circuit, and can also be realized by a combination of a general-purpose processor (such as a DSP) and software. The program of each software can be recorded on a computer-readable recording medium, and can also be downloaded by wireless or wired communication. Each channel described in the embodiment can be applied to a similar control channel data transmission channel, and thus the names of these channels are not limited to the above description. Each configuration of the communication system shown in Fig. 6 and Fig. 8 can also be realized by changing the processing based on the circuit of the wireless communication device currently used and other hardware. It is. In addition, each configuration of the present invention is not limited to the above-described embodiment, and may be applied to future communication technologies, such as the contents of a standard for a 3GRP SDPA enhancement, which will be defined in the future, without departing from the gist of the present invention. It is possible to do.

Industrial applicability INDUSTRIAL APPLICATION This invention is applicable to communication systems, such as radio | wireless communication, which control communication using quality information.

Claims

The scope of the claims

1. In a communication system in which a transmitting device transmits data to a plurality of receiving devices via a common channel,

The transmitting device,

At the time of transmitting the data, when generating first control data including identification information for identifying the receiving device, the format information of the data and an error detection code, and requesting the quality information of the common channel, Is a data generating means for generating a second control data including the identification information and omitting the error detection code,

Any one of a plurality of pre-assigned common control channels is selected, and the first or second control data generated by the data generating means is transmitted to the receiving device via the selected common control channel by control information. A first transmission means for transmitting as

The receiving device,

Detecting means for monitoring the identification information of the plurality of common control channels and detecting control information addressed to itself from the control data of the common control channel;

When the control information detected by the detecting means is the first control data, correct / incorrect detection of the identification information is performed using the error detection code, and data of the common channel is detected in accordance with the format information. Decoding means for decoding

When the control information is the second control data, a second transmitting unit that transmits the quality information of the common channel assuming that the identification information is correct; A communication system comprising:

2. The first transmitting means, when transmitting a plurality of the first control data collectively, fixes a common control channel to be used to one common control channel of the plurality of common control channels. And

Before the start of data reception, the detecting means monitors a plurality of common control channels, specifies a common control channel to which the first control data addressed to the own receiving device has been transmitted, and After the start, the identified common control channel is fixedly monitored, while, when the second control data is received, the plurality of common control channels are received even after the second control data is received. 2. The communication system according to claim 1, wherein the channel is monitored non-fixedly.

3. The first transmitting means, when transmitting a plurality of the first control data collectively, fixes a common control channel to be used to one common control channel of the plurality of common control channels. In addition, when transmitting the second control data during the transmission of the first control data, the second control data is transmitted using the same common control channel as the first control data. ,

The detecting means monitors a plurality of common control channels before starting the reception of the data, specifies a common control channel to which the first control data addressed to the own receiving device has been transmitted, and after starting the reception, The identified common control channel is fixedly monitored, and during the reception of the data, it is assumed that the second control data is also transmitted on the same common control channel as the first control data. The communication system according to claim 1, wherein monitoring is performed.

4. A data transmission device for transmitting data to a plurality of receiving devices via a transmission channel,

In the case of data transmission, control information to which an error detection code is added is generated, and when requesting the quality information of the transmission channel, data for generating control information including identification information for identifying the receiving device and having no error detection code Generating means,

Transmitting means for selecting any one of the plurality of common control channels and transmitting the control information generated by the data generating means via the selected common control channel;

De-night transmission device equipped with.

5. When requesting the quality information during the overnight transmission, select the same common control channel as the control information for transmitting the data, and send the control information relating to the request for the quality information to the transmitting means. 5. The data transmitting apparatus according to claim 4, further comprising: a transmission channel determining unit that transmits the data.

6. A receiving means for receiving a plurality of common control channels,

Decoding the control information of the common control channel, and when the control information is control information relating to the transmission over time, performs error detection of the control information using an error detection code included in the control information; If the control information is a transmission channel quality information request, a reception processing unit that outputs a detection result of the control information without performing error detection;

Transmitting means for transmitting quality information based on the measured reception quality when the reception processing unit detects a request for quality information;

De-evening receiver equipped with.

7. Before starting data transmission, select all of the plurality of common control channels. After starting transmission, select a specific common control channel in a fixed manner, and select the common control channel selected by the reception processing unit. A reception channel determination unit for monitoring, wherein the reception channel selection unit selects all of the plurality of common control channels after the reception processing unit detects control information regarding a request for quality information. 7. The data receiver according to claim 6, wherein:

8. Before starting data transmission, select all of the plurality of common control channels. After starting data transmission, fixedly select a specific common control channel, and monitor the common control channel selected by the reception processing unit. a reception channel decision unit for, ^this, the reception channel determination unit, de Isseki ongoing transmission, in order to detect the control information about the request for the quality information, the same common control and control information on the data transmission The data receiving apparatus according to claim 6, wherein a channel is selected, and the reception processing unit monitors the selected common control channel. '

9. A data communication method for transmitting data to a plurality of receiving devices via a common channel and transmitting control information on the data using a plurality of common control channels,

At the time of data transfer, when generating the identification information capable of identifying the receiving device, the format information of the data, and the control information including the error detection code, and requesting the quality information of the common channel. Generating a control information including the identification information and omitting the error detection code; a first transmission step of transmitting the control information generated by the generation step using the common control channel. , A detection step of monitoring the common control channel and detecting a control message addressed to the receiving apparatus based on the identification information;

When the control information detected in the detecting step is related to data transfer, the data received from the common channel is decoded based on the format information of the data, and the identification information and the data are decoded. Performing error detection using the error detection code for evening format information;

If the control information detected in the detecting step requests the quality information, the quality information is transmitted on the assumption that the detection result of the detection step is correct without performing error detection of the identification information. A second sending step to

A data communication method characterized by comprising:

10. The identification information is information obtained by encoding channelization code set information and modulation method information to be transmitted in the data using the identification number of the receiving device.

The method according to claim 9, wherein the receiving device decodes the received data based on the channelization code set information, modulation method information, and the transport block size. Data communication method described.

11. The control information includes a first part including the identification information, transport block size information as the format information, and a hybrid ARQ.

(Automatic Repeat Request) control information and a second part including the error detection code, the transmission apparatus of the present invention, the first part, the second part of the common control channel of the common control channel Place in subframe and send 10. The overnight communication method according to claim 9 or 10, wherein the communication is performed.

1 2. In the first transmitting step, the transmitting device selects any one of the plurality of common control channels to transmit the control information, and when transmitting the data a plurality of times collectively, The fixed control channel selected for transmission of the control information corresponding to the data transmission is fixedly used,

In the detecting step, the receiving device monitors the plurality of common control channels, and, if the detected control information relates to overnight transfer, detects the detected common control channel after the start of data transfer. Intensive monitoring, and when the detected control information is related to the request for the quality information, a plurality of common control channels assigned in advance to the own receiver are monitored. The data communication method according to any one of claims 9 to 11, wherein

1 3. In the first transmitting step, the transmitting apparatus selects one of the plurality of common control channels to transmit the control information, and requests the quality information while transmitting the data. Transmitting the control information relating to the quality information using the same common control channel as the control information relating to the data transfer; and in the detecting step, the receiving device monitors the plurality of common control channels. If the detected control information is related to the overnight transfer, the detected common control channel is intensively monitored after the start of the data transfer, and the quality is monitored during the reception of the night. In order to detect the control information related to the information, the same as the control information related to the data transfer The data communication method according to any one of claims 9 to 11, wherein a common control channel is monitored.

14 4. Generate control information with an error detection code added for data transmission, generate identification information for identifying the receiver when requesting transmission channel quality information, and generate control information without error correction code. And a generation step

Selecting any one of the plurality of common control channels, and transmitting the control information generated by the overnight generation step via the selected common control channel;

A data communication method comprising:

1 5. A receiving step of receiving a plurality of common control channels;

Decoding the control information of the common control channel, and when the control information is control information relating to data transmission, performing error detection of the control information using an error detection code included in the control information; If the information is the quality requirement of the transmission channel, a reception processing step for determining the detection result of the control information without performing error detection;

A data communication method, comprising: a transmission step of transmitting quality information when a request for quality information is detected in the reception processing step.