JP2010045820A - Base station - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve detection accuracy of new transmission and retransmission, and to use redundant version information and constellation rearrangement information (Xrv) changing in new transmission and retransmission for detection of new transmission and retransmission. <P>SOLUTION: A base station compatible with an HSDPA method for informing a mobile station whether data are newly transmitted or retransmitted by an X<SB>nd</SB>includes: a detection means to detect that a condition where neither an ACK signal nor an NACK signal can not be received from the mobile station continues until next new data are transmitted after reporting the transmission of new data by the X<SB>nd</SB>; and a control part for executing control to transmit the next new data without changing the X<SB>nd</SB>in transmitting the next new data when carrying out detection. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a communication device and a retransmission control method. A typical example of a system in which these devices are used is a W-CDMA mobile communication system.

  Currently, standardization of the W-CDMA system, which is one system of the third generation mobile communication system, is being promoted by 3GPP (3rd Generation Partnership Project). As one of the themes of standardization, HSDPA (High Speed Downlink Packet Access) that provides a maximum transmission speed of about 14 Mbps in the downlink is defined.

  HSDPA employs an adaptive coded modulation system, and is characterized by, for example, adaptively switching between a QPSK modulation system and a 16-value QAM system according to the radio environment between a base station and a mobile station.

  HSDPA adopts an H-ARQ (Hybrid Automatic Repeat reQuest) system. In HSDPA, when the mobile station detects an error in the received data from the base station, data is retransmitted from the base station in response to a request from the mobile station, and the mobile station is retransmitted with already received data. It is characterized by performing error correction decoding using both received data. As described above, in H-ARQ, even if there is an error, the already received data is effectively used to increase the error correction decoding gain and to reduce the number of retransmissions.

  Main wireless channels used for HSDPA include HS-SCCH (High Speed-Shared Control Channel), HS-PDSCH (High Speed-Physical Downlink Shared Channel), and HS-DPCCH (High Speed-Dedicated Physical Control Channel).

  HS-SCCH and HS-PDSCH are both common channels in the downlink direction (that is, the direction from the base station to the mobile station), and HS-SCCH transmits various parameters related to data to be transmitted on HS-PDSCH. Control channel. The various parameters include, for example, modulation type information indicating which modulation method is used to transmit data by HS-PDSCH, the number of assigned spreading codes (number of codes), a pattern of rate matching performed on transmission data, etc. Information.

  On the other hand, HS-DPCCH is an individual control channel in the uplink direction, which is a direction from the mobile station to the base station, and an ACK signal and a NACK signal are received depending on whether or not data received via HS-PDSCH is receivable. Is used when the mobile station transmits to the base station. When the mobile station fails to receive data (when the received data is a CRC error, etc.), the base station executes retransmission control because a NACK signal is transmitted from the mobile station.

  In addition, the HS-DPCCH is also used by a mobile station that measures the reception quality (for example, SIR) of a received signal from a base station and transmits the result as a CQI (Channel Quality Indicator) to the base station. Based on the received CQI, the base station determines whether the downlink radio environment is good or not. If it is good, the base station switches to a modulation method capable of transmitting data at a higher speed. Switch adaptively to the modulation method to be transmitted.

・ "Channel structure"
Next, a channel configuration in HSDPA will be described.
FIG. 1 is a diagram for illustrating a channel configuration in HSDPA. Since W-CDMA employs a code division multiplexing system, each channel is separated by a code.

First, the channels not described will be briefly described.
CPICH (Common Pilot Channel) and P-CCPCH (Primary Common Control Channel) are downlink common channels, respectively.

  The CPICH is a channel used for channel estimation, cell search, and a timing reference for other downlink physical channels in the same cell in a mobile station, and is a channel for transmitting a so-called pilot signal. P-CCPCH is a channel for transmitting broadcast information.

Next, channel timing relationships will be described.
As shown in FIG. 1, each channel forms one frame (10 ms) with 15 slots. As described above, since CPICH is used as a reference for other channels, the heads of P-CCPCH and HS-SCCH frames coincide with the heads of CPICH frames. Here, the head of the HS-PDSCH frame is delayed by 2 slots with respect to HS-SCCH or the like, which is received after the mobile station receives the modulation type information via HS-SCCH. This is because HS-PDSCH can be demodulated by a demodulation method corresponding to the modulation type. HS-SCCH and HS-PDSCH constitute one subframe with three slots.

  This is because HS-DPCCH is not synchronized with CPICH, but is an uplink channel and is based on timing generated in the mobile station.

The above is a simple description of the channel configuration of HSDPA.
Next, the content of data transmitted on the HS-SCCH and the encoding procedure will be described.

・ "Data transmitted on HS-SCCH"
The following data is transmitted on the HS-SCCH. Each data is used for reception processing of HS-PDSCH transmitted with a delay of 2 slots.
(1) X _ccs (Channelization Code Set information)
(2) X _ms (Modulation Scheme information)
_{(3) X tbs (Transport Block} Size information)
(4) X _hap (Hybrid ARQ Process information)
(5) X _rv (Redundancy and constellation Version)
(6) X _nd (New Data indicator)
(7) _Xue (User Equipment identity)
(1) to (7) will be described.

X _{ccs in} (1) is data indicating a spreading code used when transmitting data on the HS-PDSCH (for example, data indicating a combination of the number of multicodes and a code offset), and is composed of 7 bits.

(2) X _ms is data indicating that the modulation method used in HS-PDSCH is either QPSK or 16-value QAM, and is composed of 1 bit.

X _{tbs in} (3) is data used to calculate the transport block size (data size transmitted in one subframe of HS-PDSCH) of data transmitted on the HS-PDSCH, and is composed of 6 bits. The

_{Xhap of} (4) is data indicating the process number of H-ARQ and is composed of 3 bits. The base station cannot determine whether or not the mobile station has received data until it receives ACK and NACK, but transmission efficiency decreases when it waits for transmission of a new data block until ACK and NACK are received. To do. Therefore, in order to transmit a new data block before receiving ACK and NACK, a process number is defined for each data block to be transmitted in a subframe, and the mobile station divides reception processing by the process number. That is, when performing retransmission, the base station assigns a process number to each of the transmission blocks under the condition that a process number identical to the process number at the time of transmission is given, and HS-SCCH As X _hap .

Therefore, the mobile station classifies the data received via the HS-PDSCH based on the received _Xhap, and will be described in (6) in the data stream in which the same process number is notified by the HS-SCCH. New transmission and retransmission are identified based on _Xnd , and new data and retransmission data are combined.

_{Xrv in} (5) is data indicating a redundant version (RV) parameter (s, r) and a constellation version parameter (b) at the time of retransmission of the HS-PDSCH, and is composed of 3 bits.

Specifically, when transmitting by 16-value QAM by adaptive modulation,
X _rv = 0, (s, r, b) = (1, 0, 0),
X _rv = 1, (s, r, b) = (0, 0, 0),
X _rv = 2 and (s, r, b) = (1, 1, 1),
X _rv = 3, (s, r, b) = (0, 1, 1),
X _rv = 4, (s, r, b) = (1, 0, 1),
X _rv = 5, (s, r, b) = (1, 0, 2),
X _rv = 6, (s, r, b) = (1, 0, 3),
X _rv = 7, (s, r, b) = (1, 1, 0)
When transmitting with QPSK by adaptive modulation,
X _rv = 0, (s, r) = (1, 0), X _rv = 1, (s, r) = (0, 0),
X _rv = 2, (s, r) = (1, 1), X _rv = 3, (s, r) = (0, 1),
X _rv = 4, (s, r) = (1,2), X _rv = 5, (s, r) = (0,2),
X _rv = 6, (s, r) = (1,3), X _rv = 7, (s, r) = (0,3)
And

  Note that s is a bit for indicating whether or not to prioritize systematic bits in rate matching processing described later. For example, when s = 1, the systematic bit is prioritized, and when s = 0, the systematic bit is not prioritized. r represents a bit pattern to be subjected to puncturing and repetition processing during rate matching processing, and b represents a constellation rearrangement pattern.

During retransmission, considering the synthesis on the receiving side, or to change the bit to be transmitted, it is desirable to change the constellation arrangement, used the X _rv is circulated between 0-7. Further, since it is not necessary to change _Xrv every time of initial transmission, the initial value at the time of new transmission may be constant.

_{Xnd in} (6) is data indicating whether the transmission block of HS-PDSCH is a new block or a retransmission block, and is composed of 1 bit. For example, when a new block is transmitted, the value is switched from 0 to 1, or from 1 to 0, and the same value is used without switching at the time of retransmission.

  For example, when new transmission, re-transmission, new transmission, re-transmission, re-transmission, and new transmission are performed in order, the bits change as 1, 1, 0, 0, 0, 1 and so on.

_{Xue in} (7) is data indicating identification information of the mobile station and is composed of 16 bits.

"Encoding of data transmitted on HS-SCCH"
FIG. 2 is a diagram showing an encoding procedure (encoding device) for each of the data (1) to (7) transmitted on the HS-SCCH, and is mainly executed in the base station.

  In the figure, 1 is an encoding unit, 2 is a rate matching processing unit, 3 is a multiplier, 4 is a CRC calculation unit, 5 is a multiplier, 6 is an encoding unit, 7 is a rate matching processing unit, and 8 is an encoding unit. , 9 represents a rate matching processing unit.

  Next, the operation of each block will be described.

(1) X _ccs (x _{1,1 to} x _1,7 ) expressed by 7 bits and (2) X _ms (x _1,8 ) expressed by 1 bit are encoded as a total of 8 bits. 1 is input. Here, the number in the first half of the subscript means that it relates to data transmitted in the first slot, and the number in the second half divided by comma (,) indicates the number of bits.

The encoding unit 1 adds 8 tail bits to the input data, and performs a convolutional encoding process with a code rate of 1/3 for a total of 16 bits. Therefore, the coded data becomes a total of 48 bits are provided to the rate matching unit 2 as z _{1, 1} to z _1,48. The rate matching processing unit 2 punctures and repeats predetermined bits, adjusts the number of bits to fit in the first slot (here, 40 bits), and outputs (r _1,1 to r _{1 , 40} ).
Data from the rate matching unit 2, made multiplies the c ₁ to c ₄₀ by the multiplier 3, is output as s _{1, 1} ~s _{1, 40,} in the HS-SCCH in Figure 1, of one subframe It is transmitted in the first slot (first part) which is the first slot.

Here, c _{1 to} c ₄₀ are (7) _convolution of data from X _ue (x _{ue1 to} x _ue16 ) by the encoding unit 8 after adding an 8-bit tail bit at a coding rate of 1/2. The b1 to b48 obtained by encoding are further obtained by performing the same bit adjustment as the rate matching processing unit 2 in the rate matching processing unit 9.

On the other hand, 6-bit (3) X _tbs (x _{2,1 to} x _2,6 ), 3 bits (4) X _hap (x _{2,7 to} x _2,9 ), 3 bits (5) X _rv (x _2,10 ~x _2,12), 1 bit (6) X _nd (x2,13) are a total of 13 as bit y _2,1 ~y _{2, 13,} further, 16-bit y _{2, 14} ~y _2,29 is input to the encoding section 6 as y _2,1 ~y _2,29 in total 29 bits by adding.

Here, y _2,14 ~y _2,29, in CRC calculator 4 with respect to the total 21 bits of (1) ~ (6), CRC arithmetic operation is performed, the c ₁ to c ₁₆ as the operation result (7) is obtained by multiplying the _{X ue (x ue1 ~x ue16)} .

Now, y _2,1 ~y _2,29 which is input to the encoding section 6, after the 8 tail bits are added, z _2,1 to z are convolutional encoded with code rate 1/3 The data is input to the rate matching processing unit 7 as _2,111 111-bit data.

The rate matching processing unit 7 outputs 80 bits r _2,1 to r _2,80 by the above-described processing such as puncturing, and these r _2,1 to r _2,80 are in the HS-SCCH of FIG. It is transmitted in the second and third slots (second part) in one subframe.

  As described above, the data of (1) and (2) is transmitted in the first slot, and (3) to (6) are transmitted in the second to third slots. However, for these, the CRC calculation is performed in common and is transmitted as the CRC calculation result in the second slot, so that the reception error is detected by completely receiving both the first and second slots. Is possible.

In addition, since the data transmitted in the first slot is subjected to convolutional encoding by the encoding unit 1 and (7) _Xue is multiplied by the multiplier 3, the data addressed to the other station is transferred to the first slot. Since the likelihood (path metric value, etc.) generated in the decoding process is smaller than that addressed to the local station, there is a possibility that the likelihood is not addressed to the local station by comparing the likelihood with the reference value. It will be understood that it is expensive.

"Encoding of data transmitted on HS-PDSCH"
Next, a process until transmission data is transmitted via HS-PDSCH will be described with reference to a block diagram.

  FIG. 3 is a diagram showing a transmission apparatus according to the present invention.

  As an example of the transmission apparatus, a transmission apparatus (radio base station) of the W-CDMA communication system corresponding to the HSDPA described above will be described. It is also possible to apply to a transmission device in another communication system.

In the figure, reference numeral 10 denotes a control unit that sequentially outputs transmission data (data to be transmitted within one subframe) transmitted via the HS-PDSCH and controls each unit (11 to 26, etc.). The values of (1) to (7) described in FIG.
Since HS-PDSCH is a common channel, transmission data that are sequentially output are allowed to be addressed to different mobile stations.

  11 is a CRC attachment unit for performing CRC calculation on sequentially input transmission data (data to be transmitted in the same radio frame) and adding a CRC calculation result to the end of the transmission data; A bit scrambling unit that gives transmission data randomness by scrambling transmission data to which the CRC calculation result is added in units of bits is shown.

  13 is a bit input for the purpose of preventing an increase in the amount of computation of the decoder on the receiving side due to the data length to be encoded becoming too long in the next channel encoding. A code block segmentation unit that divides (for example, bisects) when scrambled transmission data exceeds a predetermined data length. In the figure, the output when the input data length exceeds a predetermined data length and is divided into two equal parts (divided into a first data block and a second data block) is shown. Of course, an example in which the number of divisions is other than 2 is also conceivable, and an example in which the data is not divided equally but divided into different data lengths is also conceivable.

Reference numeral 14 denotes a channel coding unit that performs error correction coding processing on each divided data separately. Note that the above-described turbo encoder is preferably used as the channel encoding unit 14, and a turbo encoder is also used here.
Therefore, as described above, the first output is obtained by convolutionally encoding the systematic bits (U) and the systematic bits (U), which are the same data as the data to be encoded, for the first block. The obtained first redundant bit (U ′) and the second redundant bit (U ″) obtained by interleaving the systematic bit and then performing convolutional coding in the same manner are included. Similarly, the second output includes a systematic bit (U), a first redundant bit (U ′), and a second redundant bit (U ″) for the second block.

  15 is a systematic bit (U), a first redundant bit (U ′), and a second redundant bit (U ″) for the first block and the second block serially input from the channel encoder 14 (turbo encoder). ) Shows a bit separation part to be output separately.

16 is input so that the input data (all of the data of the divided blocks in the case of dividing into a plurality of blocks) has a data amount that fits in a predetermined area of the virtual buffer unit 17 at the subsequent stage. a first rate matching (1 ^st rate matching) unit for performing rate matching processing such as puncturing processing (thinning) for data.

  17 is a virtual buffer (set by the control unit 10 in accordance with the reception processing capability of the mobile station to be transmitted, and in which data subjected to rate matching processing by the first rate matching unit 16 is stored. Buffer) part. At the time of retransmission, by outputting the stored data, the processing from the CRC adding unit 11 to the first rate matching unit 16 can be omitted. However, if the coding rate is to be changed at the time of retransmission, the stored data is stored. It is desirable to output the transmission data stored in the control unit 10 again without using the processed data. It should be noted that a buffer is not actually provided as the virtual buffer unit 17 and can be made through as it is. In this case, the retransmission data is output again from the control unit 10.

18, the control unit 10, shows a second rate matching (2 ^nd rate matching) unit for adjusting the data length that can be accommodated in one subframe specified, puncturing (thinning), repetition processing (repetition ) To adjust the data length of the input data so that the specified data length is obtained.

  The second rate matching unit 18 performs rate matching processing according to the RV parameters described above.

  That is, according to the RV parameter, when s = 1, rate matching processing is performed so as to leave as many systematic bits as possible, and when s = 0, the systematic bits are decreased, and redundant bits are increased. It is permissible to remain much. Further, puncture processing and rate matching processing are performed by a pattern according to r.

  Reference numeral 19 denotes a bit collection unit that arranges data from the second rate matching unit 19 in a plurality of bit strings. That is, by arranging the data of the first block and the data of the second block by a predetermined bit arrangement method, a plurality of bit strings for indicating signal points on the phase plane are output. In this embodiment, since the 16-value QAM modulation method is used, the bit string is composed of 4 bits. However, when the 64-value QAM modulation method is used, the bit string is 6 bits, and when the QPSK modulation method is used, the bit string is 2 bits. Make it a bit.

  20 divides and outputs the bit string to the same number of systems as the number of spreading codes (number of codes) notified by the control unit 10. That is, when the number of codes in the transmission parameter notified by the control unit 10 is N, a physical channel segmentation unit that divides an input bit string into 1 to N systems in order and outputs the system.

  Reference numeral 21 denotes an interleaving unit that performs interleaving processing on each of the N bit strings and outputs the result.

  Reference numeral 22 denotes a constellation re-arrangement for 16 QAM unit that can re-arrange bits in each bit string for each input bit string. The bits are rearranged according to the constellation version described above. An example of the bit rearrangement is processing such as switching the upper bit and the lower bit, and it is preferable to perform bit switching according to the same rule for a plurality of bit strings.

  Reference numeral 23 denotes a physical channel mapping unit that distributes N-system bit strings to the corresponding spreading units of the diffusion processing unit 24 in the subsequent stage.

  24 includes a plurality of spreading sections, each of which outputs a corresponding I and Q voltage value based on each of N systems of bit strings, and performs a spreading process using different spreading codes, and outputs a spreading process (Spreading) section. Show.

  25 synthesizes each signal spread by the spread processing unit 24, performs amplitude phase modulation such as a 16-value QAM modulation system based on this, amplifies it by a variable gain amplifier, and further converts the frequency into a radio signal Then, a modulation unit that enables output to the antenna side and transmission as a radio signal is shown.

  In HSDPA, signals destined for other mobile stations can be multiplexed by spreading codes even in subframes of the same timing, so a set of 10 to 25 and a variable gain amplifier (referred to as a transmission set) Preferably, the output signals of the variable gain amplifiers are combined and then frequency-converted in common before being transmitted to the antenna side. Of course, since the codes need to be separated, the spread codes used in the spread processing unit 24 in each transmission set are different spread codes so that they can be separated.

  Reference numeral 26 denotes a reception unit, which receives a signal from a mobile station received via HS-DPCCH or the like, and gives an ACK, NACK signal, CQI, or the like to the control unit 10.

  As described above, when the ACK signal is received, the next new data is transmitted. However, in the DTX state where there is no NACK signal or response, the control unit 10 performs retransmission control so as to retransmit the transmitted data. . Note that the retransmission is limited to the set maximum number of retransmissions, and if the ACK signal cannot be received from the mobile station even when the maximum number of retransmissions is reached, the transmission is controlled to be switched to the transmission of the next new data.

  If the maximum number of retransmissions is not defined, the timer can be started from a new transmission, and if an ACK signal cannot be received even if it has been detected that a predetermined time has elapsed, it can be switched to the next transmission of new data.

  The above is the description of each part name and its operation.

The matters related to HSDPA described above are disclosed in Non-Patent Documents 1 and 2 below, for example.
3G TS 25.212 (3rd Generation Partnership Project: Technical Specification Group Radio Access Network; Multiplexing and channel coding (FDD)) 3G TS 25.214 (3rd Generation Partnership Project: Technical Specification Group Radio Access Network; Physical layer procedures (FDD))

According to the background art described above, the receiving apparatus determines whether received data (HS-PDSCH) is new transmission or retransmission based on data (X _nd ) for identifying whether it is new transmission or retransmission. However, this data (X _nd ) may be _missed .
For example, when X _nd is changed to 000011110 according to new transmission and retransmission, the mobile station fails to receive the HS-SCCH part of 1111 (if it cannot be received at all, HS-SCCH is a CRC error. When the mobile station receives 00000 from the base station, it is determined that the retransmission has been performed four times. When H-ARQ is adopted, this new data is erroneously combined with already received data.

Accordingly, one of the objects of the present invention is to improve the detection accuracy of new transmissions and retransmissions.
Also, one of the objects of the present invention is to make it possible to use new transmission, redundant version information that changes at the time of retransmission, and constellation relocation information (X _rv ) for detection of new transmission and retransmission.

  It is to be noted that the present invention is not limited to the above-described object, and is an effect derived from each configuration shown in the best mode for carrying out the invention described later, and has an effect that cannot be obtained by the conventional technique. Can be positioned as one.

(1) In the present invention, in the base station corresponding to the HSDPA method to notify the mobile station of whether to re-transmit or to transmit data to the new by X _nd, by the X _nd, to send new data After the notification, the detecting means for detecting that the state in which neither the ACK nor the NACK can be received from the mobile station has continued until the next new data is transmitted, and when the next new data is transmitted, A base station including a control unit that controls to transmit without changing _nd is used.

  (2) In the present invention, in the base station notifying the mobile station that the transmission is new data by changing the bit and notifying the mobile station that the transmission is not performed by changing the bit, A detection means for detecting that a state in which neither ACK nor NACK can be received from a mobile station continues until transmission of the next new data after notification of transmission of new data due to a bit change; At the time of the next transmission of new data, a base station comprising a control unit for controlling transmission without changing the bits is used.

  ADVANTAGE OF THE INVENTION According to this invention, the detection precision of new transmission and retransmission can be improved in a receiver.

Further, according to the present invention, the new transmission and the detection of retransmission, new transmission, redundant version information that changes at the time of retransmission, and constellation rearrangement information (X _rv ) can be used in the receiving apparatus.

It is a figure which shows the channel structure in HSDPA. It is a figure which shows the encoding part of HS-SCCH. It is a figure which shows a transmitter (radio base station). It is a figure which shows the radio | wireless apparatus (mobile station) which concerns on this invention. It is a figure which shows the new transmission and resending determination flow using Xrv. It is a figure which shows resending control at the time of normal (when there is no HS-SCCH reception error). It is a figure which shows the problem of the resending control operation at the time of HS-SCCH burst error. It is a figure which shows the resending control operation at the time of HS-SCCH burst error.

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

[A] Description of First Embodiment As described above, the second to third slots of one subframe transmitted on the HS-SCCH include (5) X _rv. Therefore, it was decided to pay attention to _Xrv in (5).
X _rv is data indicating the redundancy version (RV) parameter (r, s) and the constellation version parameter (b) at the time of retransmission of the HS-PDSCH, as described above. The parameter is changed at the time of retransmission.
Therefore, this X _rv is used to identify new transmission and retransmission.

  FIG. 4 is a diagram showing a communication apparatus according to the present invention.

  As an example of the wireless device, a mobile station in the W-CDMA communication system corresponding to the HSDPA described above will be described. It is also possible to apply to communication devices in other communication systems.

  In the figure, 31 is an antenna, 32 is a radio unit that performs radio processing such as down-conversion on a radio signal, 33 is an A / D conversion unit that converts an analog signal converted to an intermediate frequency or the like into a digital signal, and 34 is A storage unit for storing the reception signal converted into a digital signal by the A / D conversion unit is shown. Reference numeral 35 denotes a first demodulation unit for performing HS-SCCH demodulation processing (orthogonal detection, despreading processing, etc.). Reference numeral 36 denotes a first decoding unit for decoding the first slot of the HS-SCCH. Note that a Viterbi decoder is preferably used as the decoding unit.

_{Reference numeral} 37 denotes a separation unit for separating X _ccs and X _ms included in the first slot, and 39 denotes a conversion unit that gives a corresponding P value and O value to the control unit 47 described later based on X _ccs .

  Reference numeral 40 denotes a second decoding unit for decoding the second and third slots of the HS-SCCH. Note that a Viterbi decoder is preferably used as the decoding unit.

_{Reference numeral} 41 denotes a separation unit that separates and outputs X _tbs , X _hap , X _rv , and X _nd included in the second and third slots.

43 is a conversion unit that converts the data into corresponding data length information based on X _tbs and then _supplies the data to the control unit 47, and 44 converts the information into corresponding information such as a rate matching parameter based on X _rv. The conversion part to give is shown.

  45 is demodulation processing such as orthogonal detection and despreading for a signal transmitted via the HS-PDSCH (detection method, number of despreading codes used for despreading, etc. is the first part in the subframe of the immediately preceding HS-SCCH. 46 indicates a third decoding unit that performs decoding processing such as turbo decoding on HS-PDSCH data.

  Note that the mobile station as the radio apparatus shown in FIG. 4 includes a transmission unit for outputting signals such as CQI, ACK, and NACK from the control unit 47 and can transmit them as radio signals from the antenna 31. However, illustration is abbreviate | omitted.

  Next, the operation of the wireless device shown in FIG. 4 will be described.

  Since a mobile station in a communication state using HSDPA has HS-PDSCH as a common channel, first, whether HS-SCCH is periodically received and data addressed to the mobile station is transmitted by HS-PDSCH. Need to check.

Therefore, the mobile station converts the signal received by the antenna 31 and down-converted by the radio unit 32 into a digital signal by the A / D conversion unit 33, stores the digital signal in the storage unit 34, and converts the digital signal into the first demodulation unit. 35. Since the first demodulator is a demodulator for demodulating HS-SCCH, as described above, for example, the received signal is despread simultaneously using four types of spreading codes, and the despread data ( The first slot portion) is input to the first decoding unit 36. In the first decoding unit 36, c _{1 to} c ₄₀ (these are the same as the base station by performing the same processing as the encoding unit 8 and the rate matching processing unit 9 in the mobile station based on X _{ue of} (7). (C _{1 to} c ₄₀ ) are multiplied, and data with a likelihood of 0 is inserted into the bit portion deleted (punctured) by the rate matching process in the rate matching processing unit 2, and then the decoding process is performed by Viterbi decoding or the like To do. Here, the data with likelihood 0 is used in order to obtain an influence level equal to the determination of 1 or 0 in the decoding process.

Data decoded by the first decoding unit 36, by the demultiplexer 37 is separated into X _ccs and X _ms, is converted into X _ccs is input to the conversion unit 39, code information used in (1) Control This is notified to the unit 47.

  Next, the decoding process of the second and third slots and the HS-PDSCH will be briefly described.

The second decoding unit 40 performs a decoding process on the second and third slot portions, and provides the decoding result to the separation unit 41 and the CRC check unit 42. The separation unit 41 separates the input second and third slot portions into X _tbs , X _hap , X _rv , and X _nd and outputs them. For X _tbs , the data length information corresponding to the input data is given to the control unit 47 by the conversion unit 43, so that the data length in one subframe transmitted on the HS-PDSCH can be recognized.
Further, X _hap is directly given to the control unit 47 as a process number. As described above, the control unit 47 processes the data blocks transmitted by the HS-PDSCH as the same process or separate processes. Judge whether to process as.
_Xrv is converted into s, r, and b by the association described above by the conversion unit 44, is given to the control unit 10, and is used for specifying a rate matching pattern and a constellation version.

・ "Determination of new transmission and retransmission using _Xrv "
Further, in this embodiment, _Xrv is used to identify new transmission or retransmission. In addition, the base station changes X _rv at the time of retransmission (for example, 0 to 7) to change the transmitted bit or change the constellation arrangement so that the systematic bit is advantageous. Although or, for each new transmission it is not necessary to change the X _rv during, the same thing in a particular value in the X _rv when new transmission.

Therefore, the control unit 47 stores this specific value (for example, X _rv = 0) or stores a value other than this specific value, and detects that the received X _rv is this specific value. Determines that it is a new transmission (determines that it is not a retransmission), and if it detects that the received X _rv is not this specific value, it does not determine that it is a new transmission (determines that it is a retransmission). .

  If a specific value differs for each business operator, a specific value is stored in advance for each business operator, and the business operator is selected based on network information (broadcast information, etc.) transmitted from the base station. A specific value can be read and used.

In addition, although _Xrv used for new transmission is a specific value, the mobile station may not store it.

In this case, the control unit 47 of the mobile station stores the history of received X _rv (or s, r, b), and identifies X _rv at the time of new transmission based on the stored X _rv .

Specific methods include, for example, to determine the value of the most received X _rv as X _rv when new transmission. This is because _Xrv is cyclically used for each re-transmission, and transmission may be successful only after one new transmission, and re-transmission may not be performed. As a result, the appearance rate is the highest. This is because X _rv at the time of new transmission is considered.

In order to improve the specific accuracy, it is preferable to refer to _Xnd when specifying. That is, the value of _Xrv when it is determined that _Xnd is a new transmission is used. However, since there is a possibility that the judgment of new transmission itself is erroneous, it is preferable to store a plurality of X _rv values when it is judged that X _nd is a new transmission, and to specify the most stored value of X _rv And stored in the above manner.

When the most frequently stored X _rv is used as a specific value, and the specific value is received as X _rv and it is determined that the transmission is new, the following problem may occur.

For example, if the value of the maximum number of retransmissions is large (time until switching to transmission of the next new data) and _Xrv is circulated once, the specific value is transmitted again even at the time of retransmission. Therefore, the place to be determined as retransmission is erroneously determined as new transmission.

Therefore, preferably, the control unit 47 of the mobile station not only stores X _rv but also stores the history in time series. Then, based on the stored history information, a series of X _rv change patterns starting from X _rv at the time of new transmission and returning to X _rv at the time of new transmission is extracted, and the order is stored as the change pattern. deep. Then, the change in X _rv received as compared to its memorized change pattern, when it is detected that the received X _rv is round, also the next received X _rv is a X _rv at new transmission, new transmission It is desirable to determine that it is related to retransmission (or not to perform new / retransmission determination using _Xrv ). Here, when 8 types of X _rv are known, it is detected that 8 types of reception X _rv are received continuously, and similarly, even if the next reception X _rv is X _rv at the time of new transmission, It is not determined to be new transmission, but is determined to be related to retransmission (or new / retransmission determination using _Xrv is not performed).

Furthermore, _Xrv used for new transmission may be different for each base station, for each jurisdiction RNC (base station control device), for each MMS (routing device such as a switching device), and for each carrier.

In this case, the base station number, jurisdiction RNC (base station control device) identification information, MMS (routing device such as switching device) identification information, operator, etc., to be notified when detecting a specific value referring to _{Xnd Xrv} is distinguished and stored between items having the same identification information, and the maximum value is stored for each base station, each RNC (base station control device), each MMS (routing device such as switching device), and the operator. Store and use every time.

X _nd is a bit indicating whether the data transmitted on the corresponding HS-PDSCH is new or retransmitted, and is given to the control unit 47 as it is.
As described above, the new transmission by X _rv, although retransmission may be identified, and information X _nd, may be identified on the basis of the X _rv.

That is, if X _nd indicates new transmission, it is determined as new transmission as it is, if X _nd indicates retransmission, it is determined whether X _rv indicates new transmission, and if it indicates new transmission, it is determined as new transmission. If it is determined and retransmission is indicated, it is determined as retransmission.

In this way, when transmitting with X _nd changed to 000011110, the mobile station failed to receive the 1111 portion of HS-SCCH (including the case where HS-SCCH results in a CRC error if it cannot be received at all). ), When the last X _nd = 0 is received, X _nd is determined to be retransmission, but since X _rv is a value indicating new transmission, it is relieved and correctly detected as new transmission Will be able to.

As described above, new transmission and retransmission can be determined by _Xrv alone, and _Xnd and _Xrv can be determined.
New transmission and re-transmission can be determined based on both.

  Of the second and third slots, the CRC check unit 42 receives both the CRC bits calculated by the CRC calculation and the data of the first to third slots that are the targets of the CRC calculation on the transmission side. The check unit 42 compares the result obtained by performing the CRC calculation on the CRC calculation target with the received CRC bit, and checks whether there is a CRC error (existence) based on the match (mismatch).

  The CRC check result is given to the control unit 47. If there is an error due to the CRC check, it is preferable to perform control so as not to perform the subsequent operation of each unit regarding the HS-PDSCCH.

  The second demodulator 45 performs demodulation when no error is detected in the CRC check, outputs a demodulation result, and sequentially decodes the received data as a separate process for each process number notified by HS-SCCH. To the control unit 47.

  The control unit 47 reconstructs the data based on the information included in the data separately decoded for each process number, reproduces the transmission data, and outputs it to a display unit, an audio output unit, etc. (not shown).

  Although not shown, the mobile station also includes a transmission unit, and can transmit ACK, NACK, and CQI according to an instruction from the control unit 47 as described above.

Finally, FIG. 5 shows a determination flowchart of new transmission and retransmission using both _Xnd and _Xrv .

In step 1, the control unit 47 of the mobile station determines whether or not _Xnd received via the HS-SCCH has changed. Here, when it changes, it progresses to step 2 and the decoding process of the received data of HS-PDSCH is performed in the 3rd decoding part 46, without combining with other data as new data. The control unit 47 performs a CRC check on the decoded data (step 3). If the CRC check is OK, the transmitting unit (not shown) is controlled so as to transmit an ACK signal to the base station (step 4), and the process returns to step 1 to perform processing for the next HS-SCCH.

On the other hand, if it is determined in step 1 that X _nd does not change, the process _proceeds to step 5 to determine whether X _rv indicates new data. If YES is determined here, the process proceeds to step 2. If NO is determined, the process proceeds to step 6. In step 6, since there is a high probability that the data is related to retransmission, the received data and the data received by retransmission are combined. Similarly, in step 7, the third decoding unit 46 performs a decoding process.

  After decoding, a CRC check is performed in step 8, and if the CRC check is OK, the process proceeds to step 4 and an ACK signal is returned to the base station. On the other hand, if the CRC check is NG, the process proceeds to step 9 and a NACK signal is returned to the base station.

If the CRC check in step 3 is NG, the process similarly proceeds to step 9 and a NACK signal is returned to the base station.
Although the above is description of 1st Embodiment, the 1st demodulation part 35 and the 2nd demodulation part 45 can also be made into a common unit, and the 1st decoding part 36 and the 2nd decoding part 40 can also be made into a common unit.

  At this time, it should be noted that even processing for signals in the same slot can be easily performed by time division processing.

[B] Description of the second embodiment In the second embodiment, the mobile station estimates the maximum number of retransmissions (or the time until switching from a new transmission to the next new transmission), so that the detection accuracy of new transmission and retransmission is determined. To improve.

When the most frequently stored X _rv is used as a specific value, and the specific value is received as X _rv and it is determined that the transmission is new, the following problem may occur.

For example, if the value of the maximum number of retransmissions (or the time) is large and X _rv circulates once, the specific value will be transmitted again even at the time of retransmission. The power should be mistakenly determined as a new transmission.

Therefore, preferably, the control unit 47 of the mobile station counts up, the continuously or elapsed time transmitted many times NACK is notified of the transmission of the next new data X _nd the receipt of new data, The count value or the number obtained by subtracting 1 from the number of transmissions (maximum number of retransmissions) or the elapsed time is stored. Here, a value obtained by subtracting 1 indicates the maximum number of retransmissions. This is because new data is transmitted without being retransmitted for the subsequent NACK.

  The control unit 47 then counts the number of consecutive NACK transmissions from the reception of new data, and compares it with the stored count value (or elapsed time), or compares the number minus 1 with the maximum number of retransmissions. It is desirable to determine that the data transmitted in response to the NACK at that time is new data.

  Here, when detecting by elapsed time, the elapsed time from reception of new data is counted, and if the count value stored matches is detected without transmitting the ACK signal, the next received data is the next new data. It is desirable to determine that the data has been switched.

In order to increase the accuracy of the stored count value, it is desirable to use X _nd and X _rv . That is, in calculating the stored count value and the maximum number of retransmissions, the HS-SCCH transmitted for all consecutive NACK transmissions is not simply counted, but _Xnd or _Xrv The count value of the NACK signal is validated only when it indicates that retransmission is performed. In addition, for the last NACK signal transmission, since it is normally notified by X _nd or X _rv that it is a new transmission, the count value is obtained by notifying that it is a new transmission. Is valid. B, which stores the time to switch to the next new data, similarly indicates that the HS-SCCH transmitted for all consecutive NACK transmissions is a retransmission by _Xnd or _Xrv. It is desirable to measure and store the elapsed time only in cases.

Similarly, in determining new data and retransmission data based on the stored count value, it is desirable to use X _nd and X _rv in the same manner.

In the description a third embodiment of the [c] Third Embodiment, consider the determination using X _nd, new transmission in the determination using the X _rv, the operation when the conclusion retransmission are different. In such a case, it is understood that one of the determination results by X _nd and X _rv is incorrect, but here, if it is determined to be retransmitted, it will be combined with the received data. In this embodiment, the new transmission is determined.

By processing as a new transmission, it is possible to detect that it is the same data based on the information contained in the result of decoding as a new transmission, even if it is a retransmission, without being combined with the received data Therefore, it is possible to prevent duplicate output.
[D] Description of the fourth embodiment In the first embodiment, the processing in the mobile station that is the communication device on the receiving side is devised. In the fourth embodiment, the processing in the base station that is the communication device on the transmitting side is performed. Devise.

  First, the retransmission control at the normal time (when there is no HS-SCCH reception error) will be described using FIG.

As shown in the figure, the base station transmits X _nd = 0 via the HS-SCCH, the mobile station receives this normally, determines that X _nd = 0, and no CRC error is detected on the HS-SCCH. Therefore, HS-PDSCH is decoded.

  Then, a CRC check is performed on the HS-PDSCH after decoding. If the CRC check becomes NG due to the influence of the reception environment or the like, a NACK signal is transmitted to the base station as shown in the figure.

Here, since the maximum value of the number of retransmissions is 3, the base station receives the NACK signal from the mobile station four times or does not receive the ACK signal from a new transmission within a predetermined time (when time is over). Gives up the retransmission and sends X _nd = 1 over the HS-SCCH to send the next new data, the mobile station receives it normally, determines that X _nd = 1, and HS -Since no CRC error is detected on SCCH, HS-PDSCH is decoded.

  However, similarly, when the CRC check for the decoded HS-PDSCH is NG, a NACK signal is transmitted to the base station as shown in the figure, and the base station receives the fourth NACK signal (or due to time over). Switch to transmission of new data.

As described above, when the HS-SCCH is normally received by the mobile station, there is no deviation in recognition of new and retransmission based on _Xnd between the base station and the mobile station.

  However, as shown in FIG. 7, when a burst error occurs in the HS-SCCH, there will be a shift in recognition of new and retransmission.

That is, as shown in the figure, the first four times of X _nd are received by the mobile station, but X _nd = 1 at the time of the fifth new data transmission when the maximum number of retransmissions has been reached (or when time is over) is May not be received by the mobile station (including CRC error).

  In such a case, the mobile station does not decode HS-PDSCH, and enters a DTX state in which neither ACK nor NACK is transmitted to the base station.

  Therefore, although the base station does not receive the ACK signal within a predetermined time from the transmission, the base station automatically performs retransmission, but these may not be received by the mobile station as well.

When the maximum number of retransmissions is exceeded, new data is transmitted. In this case, X _nd = 0 is changed, but if the mobile station happens to receive it normally, If the station does not recognize the maximum number of retransmissions, the station determines that it is a further retransmission and combines it with the data received for the first to third times as the fourth retransmission and performs decoding.

As described above, there is a case where a retransmission is notified even though X _nd = 0 is transmitted to notify that the transmission of new data has been switched.

In this embodiment, when the mobile station fails to receive the HS-SCCH, that is, _Xnd or _Xrv , the mobile station does not decode the HS-PDSCH, so that no response (DTX) is returned in which neither ACK nor NACK is returned. Pay attention.

That is, the control unit 10 of the base station forewarned that the Nth new data is transmitted on the HS-PDSCH via the HS-SCCH, but neither ACK nor NACK is returned from the mobile station. When it is determined from the reception state from the receiving unit 26 that the process has continued until the time reaches (or until the time is over), _Xnd is not changed for the (N + 1) th new data to be transmitted next.

Specifically, as shown in FIG. 8, the first new data, as X _nd, it sends 0,0,0,0, in the order of 1,1,1,1 as X _nd the second new data In case of transmission, if neither ACK nor NACK is transmitted from the mobile station for the 5th to 8th 1s (in the case of DTX), if 3rd new data is transmitted next, 1 is set as _Xnd Then, the control unit 10 sets 1 to _Xnd shown in FIG.

If the mobile station can detect this X _nd = 1, it can detect that it has changed to X _nd = 1 after receiving X _nd = 0 continuously four times. It can be correctly judged that there is.

It should be noted that setting X _nd = 1 in this way can continue until the next fourth new data is transmitted, and if neither ACK nor NACK is returned, the next fourth new data is further transmitted. You may continue until

DESCRIPTION OF SYMBOLS 1 Encoding part 2 Rate matching process part 3 Multiplier 4 CRC calculating part 5 Multiplier 6 Encoding part 7 Rate matching process part 8 Encoding part 9 Rate matching process part 10 Control part 11 CRC addition part 12 Bit scramble part 13 Code Block division unit 14 Channel coding unit 15 Bit separation unit 16 First rate matching unit 17 Virtual buffer unit 18 Second rate matching unit 19 Bit collection unit 20 Physical channel division unit 21 Interleave processing unit 22 Constellation rearrangement unit 23 Physical channel Mapping unit 24 Spreading processing unit 25 Modulating unit 26 Receiving unit 31 Antenna 32 Radio unit 33 A / D conversion unit 34 Storage unit 35 First demodulation unit 36 First decoding unit 37 Separation unit 39 Conversion unit 40 Second decoding unit 41 Separation unit 42 CRC check unit 43 conversion unit 44 conversion unit 45 second demodulation unit 46 Third decoding unit 47 Control unit

Claims (2)

In the base station corresponding to the HSDPA method to notify the mobile station of whether to re-transmit or to transmit data to the new by X _nd,
Detecting means for detecting that a state in which neither an ACK signal nor a NACK signal can be received from a mobile station continues until the next new data is transmitted after notifying that X _nd transmits new data;
And a control unit that controls to transmit without changing _Xnd when the next new data is transmitted when the detection is performed. In the base station notifying the mobile station that it is a transmission of new data by changing the bit, and notifying the mobile station that it is a retransmission by not changing the bit,
Detecting means for detecting that the state in which neither the ACK signal nor the NACK signal can be received from the mobile station continues until the next new data is transmitted after notifying that the new data is transmitted by the bit change;
And a control unit that controls to transmit without changing the bit when the next new data is transmitted when the detection is performed.

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