WO2010109524A1 - Radio communication system, transmission station device, reception station device, and radio communication method in radio communication system - Google Patents

Radio communication system, transmission station device, reception station device, and radio communication method in radio communication system Download PDF

Info

Publication number
WO2010109524A1
WO2010109524A1 PCT/JP2009/001333 JP2009001333W WO2010109524A1 WO 2010109524 A1 WO2010109524 A1 WO 2010109524A1 JP 2009001333 W JP2009001333 W JP 2009001333W WO 2010109524 A1 WO2010109524 A1 WO 2010109524A1
Authority
WO
WIPO (PCT)
Prior art keywords
packet data
station device
unit
quality
packet
Prior art date
Application number
PCT/JP2009/001333
Other languages
French (fr)
Japanese (ja)
Inventor
大渕一央
田島喜晴
太田好明
Original Assignee
富士通株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 富士通株式会社 filed Critical 富士通株式会社
Priority to PCT/JP2009/001333 priority Critical patent/WO2010109524A1/en
Priority to JP2011505656A priority patent/JPWO2010109524A1/en
Publication of WO2010109524A1 publication Critical patent/WO2010109524A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0023—Systems modifying transmission characteristics according to link quality, e.g. power backoff characterised by the signalling
    • H04L1/0026—Transmission of channel quality indication
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
    • H04L1/1867—Arrangements specially adapted for the transmitter end
    • H04L1/1887—Scheduling and prioritising arrangements

Definitions

  • the present invention relates to a radio communication system, a transmission station apparatus, a reception station apparatus, and a radio communication method in the radio communication system.
  • AMC Adaptive Modulation and There is a technique called control.
  • a terminal apparatus MS: Mobile Station
  • CQI Channel Quality Indicator
  • BTS Base Transceiver Station
  • the base station apparatus selects a modulation scheme and an error correction coding rate based on the CQI.
  • HARQ Hybrid There is also a technique called “Automatic Repeat request” (for example, Non-Patent Documents 1 and 2 below).
  • the terminal apparatus transmits an ACK signal when it can correctly receive a new packet transmitted from the base station apparatus, and transmits a NACK signal when it cannot be received correctly.
  • the base station apparatus retransmits the packet.
  • the terminal device combines the retransmission packet and the packet received so far, and determines whether or not the packet has been correctly received. Also, the base station device stops transmission of retransmission packets when a NACK signal is received even after a predetermined time has elapsed.
  • the transmitting side estimates a communication quality that is insufficient when transmitting a retransmission packet, generates a retransmission packet so as to satisfy the insufficient communication quality, and A transmission is also disclosed (for example, Patent Documents 1 to 4 below).
  • 3GPP TS36.321 V8.3.0 3GPP TS25.321 JP 2002-9741 A JP 2003-264873 A Japanese Patent Laid-Open No. 2002-5003 JP 2004-112597 A
  • the base station apparatus performs retransmission control by HARQ
  • the base station apparatus stops transmission of the retransmission packet after a predetermined time has elapsed
  • the subsequent processing is delayed by a predetermined time.
  • radio resources are wasted.
  • one of the objects of the present invention is to provide a wireless communication system, a transmitting station apparatus, a receiving station apparatus, and a wireless communication system that are designed to prevent delay.
  • Another object of the present invention is to provide a wireless communication system or the like that effectively uses wireless resources.
  • the transmission station apparatus includes a transmission unit that transmits packet data to the reception station apparatus, and the packet data
  • a receiving unit that receives from the receiving station device a response signal indicating that the packet was not correctly received, and the receiving station device received the packet data and when the packet data could not be received correctly
  • a transmission unit that generates the response signal and transmits the response signal to the transmission station apparatus, and the transmission station apparatus or the reception station apparatus estimates and estimates communication quality when the packet data is transmitted or received, respectively.
  • a control unit for controlling so as not to perform retransmission of the packet data.
  • the transmitting unit that transmits packet data to the receiving station apparatus, and the packet data cannot be received correctly
  • a receiving unit that receives a response signal indicating from the receiving station device, and a communication quality when the packet data is transmitted, and when the estimated communication quality is higher than a required quality, even when the response signal is received
  • a control unit that controls not to retransmit the packet data.
  • a receiving unit that receives packet data transmitted from the transmitting station apparatus, and the packet data cannot be received correctly
  • a transmission unit that generates the response signal and transmits the response signal to the transmitting station device, and estimates the communication quality when the packet data is received.
  • the packet data And a control unit that controls not to retransmit the packet data even when the packet data cannot be correctly received.
  • a wireless communication method in a wireless communication system that performs wireless communication between a transmitting station device and a receiving station device, wherein the transmitting station device transmits packet data to the receiving station device.
  • the reception station apparatus cannot correctly receive the packet data
  • the reception station apparatus generates a response signal indicating that the packet data has not been correctly received and transmits the response signal to the transmission station apparatus.
  • the transmitting station device or the receiving station device estimates the communication quality when transmitting or receiving the packet data, respectively, and when the estimated communication quality is higher than the required quality, Control is performed so that the packet data is not retransmitted even when the response signal is received or when the packet data cannot be received correctly.
  • FIG. 1 is a diagram illustrating a configuration example of a wireless communication system.
  • FIG. 2 is a diagram illustrating a configuration example of a transmission station apparatus (base station apparatus).
  • FIG. 3 is a diagram illustrating a configuration example of a receiving station device (terminal device).
  • FIG. 4 is a flowchart showing an operation example.
  • FIG. 5A and FIG. 5B are diagrams showing examples of transmission / reception of packets and the like.
  • FIG. 6A and FIG. 6B are diagrams showing examples of transmission / reception of packets and the like.
  • FIG. 7 is a flowchart showing an operation example.
  • FIG. 8 is a diagram illustrating a configuration example of a transmission station apparatus (base station apparatus).
  • FIG. 9 is a flowchart showing an operation example.
  • FIG. 8 is a diagram illustrating a configuration example of a transmission station apparatus (base station apparatus).
  • FIG. 10A and FIG. 10B are diagrams showing examples of transmission / reception of packets and the like.
  • FIG. 11 is a diagram illustrating a configuration example of a transmission station apparatus (terminal apparatus).
  • FIG. 12 is a diagram illustrating a configuration example of a receiving station apparatus (base station apparatus).
  • FIG. 13 is a flowchart showing an operation example.
  • FIG. 14A and FIG. 14B are diagrams showing examples of transmission / reception of packets and the like.
  • FIG. 15 is a diagram illustrating a configuration example of a receiving station apparatus (base station apparatus).
  • Wireless communication system 10 Base station apparatus (transmitting station apparatus or receiving station apparatus) 11: First error detection encoding unit 12: First error correction encoding unit 13: Buffer 14: First modulation unit 15: Second error detection encoding unit 16: Second error correction encoding unit 17: Second modulation unit 24: ACK / NACK determination unit 25: CQI determination unit 26: HARQ control unit 27: AMC control unit 29: RLC unit 34: demodulation unit 35: synthesis unit 36: buffer 37: error correction decoding Unit 38: Error detecting unit 39: Quality measuring unit 40: Grant generating unit 41: ACK / NACK generating unit 50: Terminal device (receiving station device or transmitting station device) 53: First demodulator 54: First error correction decoder 55: First error detector 56: Control information analyzer 57: Second demodulator 58: Synthesizer 59: Buffer 60: Second Error correction decoder 61: second error detector 62: CQI generator 63: ACK / NACK generator 64:
  • FIG. 1 is a diagram illustrating a configuration example of a wireless communication system 1.
  • the transmission station apparatus 100 includes a transmission unit 110 that transmits packet data to the reception station apparatus 200, and the packet data
  • a receiving unit 120 that receives from the receiving station device 200 a response signal indicating that the packet has not been correctly received.
  • the receiving station device 200 receives the packet data and 210, and receives the packet data correctly.
  • a transmission unit 220 that generates the response signal and transmits the response signal to the transmitting station device 100 when the packet data cannot be transmitted, and the transmitting station device 100 or the receiving station device 200 transmits or receives the packet data, respectively.
  • Estimate communication quality, and receive the response signal when the estimated communication quality is higher than the required quality It comprises any control unit 130 for controlling so as not to perform retransmission of the packet data (230) when or not received correctly the packet data when the.
  • the transmitting unit 110 of the transmitting station device 100 transmits packet data.
  • the receiving unit 210 of the receiving station apparatus receives the packet data, and the transmitting unit 220 transmits a response signal indicating that the packet data was not correctly received when the packet data was not correctly received.
  • the receiving unit 120 of the transmitting station device 100 receives the response signal.
  • the operation is as follows.
  • the control unit 130 estimates the communication quality when the packet data is transmitted from the transmission unit 110. When the communication quality is higher than the required quality, the control unit 130 does not retransmit the packet data even if the response signal is received. Control.
  • control unit 230 when the control unit 230 is in the receiving station device 200, the operation is as follows.
  • the control unit 230 estimates the communication quality when the reception unit 210 receives the packet data, and when the communication quality is higher than the required quality, the control unit 230 does not retransmit the packet data even when the packet data cannot be correctly received. To control.
  • the transmission station apparatus 100 since the transmission station apparatus 100 performs control so as not to retransmit the packet data, the transmission station apparatus 100 can prevent delay compared to the case where the packet data is retransmitted until a predetermined number of times or a predetermined time is reached. Effective use of resources.
  • the receiving station apparatus 200 performs control so as not to retransmit the packet data, similarly, it is possible to prevent delay and to effectively use radio resources.
  • the second embodiment is an example of a downlink direction in which packet data or the like is transmitted from a base station apparatus (hereinafter referred to as a base station) 10 to a terminal apparatus (hereinafter referred to as a terminal) 50.
  • the transmitting station device 100 is the base station 10 and the receiving station device 200 is the terminal 50.
  • FIG. 2 is a diagram illustrating a configuration example of the base station (transmitting station apparatus 100) 10 in the wireless communication system 1, and FIG.
  • the base station 10 includes a first error detection encoding unit 11, a first error correction encoding unit 12, a buffer 13, a first modulation unit 14, a second error detection encoding unit 15, Second error correction coding unit 16, second modulation unit 17, wireless transmission unit 18, transmission antenna 19, reception antenna 21, wireless reception unit 22, demodulation unit 23, and ACK / NACK determination Unit 24, CQI determination unit 25, HARQ control unit 26, and AMC control unit 27.
  • the transmission unit 110 in the first embodiment corresponds to the transmission antenna 19 from the error detection encoding unit 11, for example.
  • the reception unit 120 corresponds to the CQI determination unit 25 from the wireless reception unit 22, for example.
  • the control unit 130 corresponds to the HARQ control unit 26.
  • the first error detection encoding unit 11 performs error correction on the packet data and performs encoding.
  • the first error detection encoding unit 11 outputs the packet data so that the packet size determined by the AMC control unit 27 is obtained.
  • the first error correction encoder 12 performs error correction and encoding on the output from the first error detection encoder 11 if there is an error.
  • the first error correction coding unit 12 performs coding based on the coding rate determined by the AMC control unit 27.
  • the buffer 13 temporarily stores the encoded packet data from the first error correction encoding unit 12.
  • the stored packet data is read according to the bit pattern determined by the AMC control unit 27.
  • the buffer 13 stores the data of the new packet until an instruction from the AMC control unit 27 is made in order for the base station 10 to retransmit the new packet (hereinafter referred to as retransmission).
  • the first modulation unit 14 modulates the output from the buffer 13 by the modulation method determined by the AMC control unit 27.
  • the second error detection encoding unit 15 performs error detection and encoding on the control information including the packet size, transmission bit pattern, modulation scheme, transmission power, etc. determined by the AMC control unit 27.
  • the control information includes, for example, control information for new packets and retransmission packets.
  • the second error correction encoding unit 16 performs error correction on the output from the second error detection encoding unit 15 and performs encoding if there is an error.
  • the second modulator 17 modulates the output from the second error correction encoder 16.
  • the radio transmission unit 18 performs amplification or the like on the outputs from the first and second modulation units 14 and 17 according to the transmission power determined by the AMC control unit 27, and converts them into radio signals.
  • the wireless transmission unit 18 may generate a pilot signal (or a known signal).
  • the transmission antenna 19 transmits a radio signal from the radio transmission unit 18 to the terminal 50. From the base station 10, new packets or retransmission packets, control information, pilot signals, and the like are transmitted to the terminal 50 as radio signals. Prior to the transmission of each packet, the control information is processed by the second error detection encoding unit 15 and transmitted to the terminal 50.
  • the receiving antenna 21 receives ACK or NACK transmitted from the terminal 50, CQI, and the like.
  • the demodulation unit 23 demodulates the output from the receiving antenna 21 and outputs the demodulated ACK or NACK to the ACK / NACK determination unit 24 and the demodulated CQI to the CQI determination unit 25, respectively.
  • the ACK / NACK determination unit 24 determines ACK or NACK and outputs the result to the HARQ control unit 26.
  • the CQI determination unit 25 determines the CQI and outputs the determination result to the HARQ control unit 26 and the AMC control unit 27.
  • the HARQ control unit 26 determines whether to newly transmit or retransmit a packet based on the determination result from the ACK / NACK determination unit 24 and the determination result from the CQI determination unit 25, and the result is Notify the AMC control unit 27. Details will be described later.
  • the HARQ control unit 26 estimates the communication quality when, for example, packet data is transmitted based on the result (for example, CQI) from the CQI determination unit 25.
  • the AMC control unit 27 determines control information for a new packet or a retransmission packet based on a determination result from the CQI determination unit 25 and a new transmission or retransmission instruction output from the HARQ control unit 26.
  • the AMC control unit 27 outputs the determined transmission bit pattern to the buffer 13, the determined modulation scheme to the first modulation unit 14, and the determined transmission power to the wireless transmission unit 18. Further, when transmitting a new packet, the AMC control unit 27 further outputs the determined packet size to the error detection encoding unit 11.
  • the terminal 50 includes a reception antenna 51, a radio reception unit 52, a first demodulation unit 53, a first error correction decoding unit 54, a first error detection unit 55, a control information analysis unit 56, A second demodulator 57, a combiner 58, a buffer 59, a second error correction decoder 60, a second error detector 61, a CQI generator 62, and an ACK / NACK generator 63 , A modulation unit 64 and a wireless transmission unit 65 are provided.
  • the receiving unit 210 in the first embodiment corresponds to the error detecting unit 61 from the receiving antenna 51
  • the transmitting unit 220 corresponds to the transmitting antenna 66 from the CQI generating unit 62.
  • the receiving antenna 51 receives a radio signal transmitted from the base station 10.
  • the radio reception unit 52 converts the radio signal received by the reception antenna 51 into a signal before input of the radio transmission unit 18 in the base station 10 and outputs the signal.
  • the first demodulator 53 demodulates the control information out of the output from the radio receiver 52.
  • the first error correction decoding unit 54 performs error correction and decoding on the demodulated control information.
  • the first error detection unit 55 performs error detection on the control information output from the first error correction decoding unit 54.
  • the control information analysis unit 56 analyzes the control information after error detection, and sets the modulation method, the presence / absence and combination method and the coding rate included in the control information to the second demodulation unit 57, the combination unit 58, and the error rate, respectively. It outputs to the correction decoding part 60.
  • the second demodulator 57 demodulates the output from the radio receiver 52 based on the modulation method from the control information analyzer 56 and outputs the demodulated signal to the synthesizer 58.
  • the second demodulator 57 outputs the demodulated packet data to the synthesizer 58 and the demodulated pilot signal to the CQI generator 62.
  • the synthesizing unit 58 synthesizes the demodulated packet data and the packet data stored in the buffer 59 and outputs them to the second error correction decoding unit 60 and the buffer 59. However, since the packet data is not stored in the buffer 59 when the demodulated packet data is new packet data, the combining unit 58 outputs the packet data to the second error correction decoding unit 60 and the buffer 59 without combining them. For example, the combining unit 58 determines whether the packet data is new or retransmitted based on the presence / absence of combining from the control information analyzing unit 56.
  • the second error correction decoding unit 60 performs error correction and decoding on the packet data output from the synthesis unit 58.
  • the second error detection unit 61 performs error detection on the packet data output from the second error correction decoding unit 60.
  • the second error detection unit 61 outputs the detection result to the ACK / NACK generation unit 63. Note that the second error detection unit 61 clears the packet data stored in the buffer 59 when there is no error as a result of the error detection.
  • the CQI generation unit 62 measures downlink channel quality based on the demodulated pilot signal and generates CQI including quality information.
  • the ACK / NACK generation unit 63 generates a response signal (ACK or NACK) based on the output from the second error detection unit 61. For example, the ACK / NACK generation unit 63 generates an ACK when obtaining a detection result with no error from the second error detection unit 61 (or when packet data has been correctly received). The ACK / NACK generation unit 63 generates a NACK (retransmission request) when a detection result with an error is obtained (or when packet data cannot be correctly received).
  • the modulation unit 64 modulates the CQI output from the CQI generation unit 62 or the ACK or NACK output from the ACK / NACK generation unit 63.
  • the wireless transmission unit 65 amplifies the output from the modulation unit 64 and converts it to a wireless signal.
  • the transmission antenna 66 transmits the radio signal output from the radio transmission unit 65 to the base station 10.
  • the terminal 50 transmits ACK or NACK, CQI, and the like to the base station 10.
  • FIG. 4 is a flowchart showing an operation example in the second embodiment.
  • the flowchart shown in the figure is mainly performed by the HARQ control unit 26 and the AMC control unit 27 of the base station 10.
  • the base station 10 receives the CQI transmitted from the terminal 50 (S11).
  • the CQI received from the terminal 50 is output to the AMC control unit 27 via the reception antenna 21 and the like.
  • the AMC control unit 27 confirms the presence / absence of a retransmission packet (S12). For example, the AMC control unit 27 confirms that there is a retransmission packet if packet data is stored in the buffer 13, and that there is no retransmission packet otherwise.
  • the AMC control unit 27 confirms the presence or absence of a new packet (S13). For example, the AMC control unit 27 confirms the presence / absence of a new packet by notification from an upper layer or an upper device.
  • the AMC control unit 27 determines the packet size, modulation scheme, and coding rate based on the CQI (S14, S15).
  • the base station 10 generates and transmits a new packet based on the determined packet size and the like (S16).
  • the AMC control unit 27 performs S11 because there is no packet to be transmitted.
  • the AMC control unit 27 proceeds to the processing of S15, determines the modulation and coding rate for the retransmission packet, and transmits the retransmission packet (S16).
  • the base station 10 receives ACK or NACK for the new packet or retransmission packet from the terminal 50 (S17).
  • the ACK / NACK determination unit 24 determines ACK or NACK of the ACK or NACK transmitted from the terminal 50 via the reception antenna 21 or the like. The determination result is output to the HARQ control unit 26.
  • the HARQ control unit 26 receives an ACK (“Ack” in S18), the terminal 50 has received a new packet or a retransmission packet without error, and thus ends a series of processes without transmitting a retransmission packet ( The process proceeds to S21) and S11.
  • the HARQ control unit 26 notifies the AMC control unit 27 that retransmission is not performed, and the AMC control unit 27 clears the data of the new packet or the retransmission packet stored in the buffer 13.
  • the HARQ control unit 26 determines whether or not the number of retransmissions of the retransmission packet has exceeded a threshold (specified number) (S19). For example, the HARQ control unit 26 stores the number of retransmissions that have been retransmitted so far and a threshold value, and can determine by comparing the number of retransmissions by NACK reception and the threshold value. The HARQ control unit 26 may determine whether or not the elapsed time after transmission of a new packet exceeds a threshold value (specified time) instead of the number of retransmissions.
  • a threshold specified number
  • the HARQ control unit 26 ends the series of processes without retransmitting the retransmission packet. The process proceeds to S11.
  • the HARQ control unit 26 determines whether the quality is satisfied based on the CQI output from the CQI determination unit 25 (S20).
  • the base station 10 When the communication quality when the packet is transmitted is better than the previous communication quality, if the base station 10 receives a NACK from the terminal 50, there may be some problem on the terminal 50 side.
  • the second error detection unit 61 of the terminal 50 performs error detection on a combination of the packet data received so far and the data of the retransmission packet. For example, if the terminal 50 receives a new packet addressed to another terminal by mistake, the second error detection unit 61 detects an error no matter how many times the new packet and the retransmission packet are combined. In this case, the terminal 50 repeatedly transmits NACK.
  • the base station 10 determines that the packet is transmitted based on the excessive communication quality when the communication quality when the packet is transmitted is better than the previous communication quality. Even if the NACK is received and the specified number of times has not been reached, retransmission is not performed. Thereby, the transmission of the retransmission packet is stopped, and the wireless communication system 1 can prevent a delay in subsequent processing. In addition, the wireless communication system 1 can effectively use wireless resources. For example, the HARQ control unit 26 performs quality determination (S20).
  • the HARQ control unit 26 performs the quality determination (S20) processing by comparing, for example, “the quality of the propagation path when the packet is actually transmitted” and “the quality of the assumed propagation path”.
  • the HARQ control unit 26 determines that the quality is satisfactory (Yes in S20), and stops transmission of the retransmission packet even if the specified number of times has not been reached (S21).
  • the HARQ control unit 26 determines that the quality cannot be satisfied (No in S20), and transmits a retransmission packet (S22). And a process transfers to S11 and the base station 10 repeats the above-mentioned process.
  • FIG. 5 (A) and FIG. 5 (B) are diagrams showing examples of packet transmission / reception. These figures show an example in which retransmission is stopped by the second retransmission packet.
  • the base station 10 transmits a pilot signal.
  • the CQI generator 62 of the terminal 50 generates a CQI based on the pilot signal.
  • the generated CQI (first CQI) is transmitted to terminal 50 via modulator 64 and the like.
  • the base station 10 transmits a new packet based on the first CQI (S11 to S16 in FIG. 4).
  • the AMC control unit 27 of the base station 10 determines the size and the like of the new packet, the error detection coding unit 11 and the like perform processing such as error detection coding, and the new packet is transmitted.
  • the error detector 61 of the terminal 50 detects an error in the new packet, and the terminal 50 transmits a NACK.
  • the CQI generation unit 62 of the terminal 50 newly generates a CQI (second CQI) based on the pilot signal, and the terminal 50 transmits the CQI.
  • the base station 10 receives the NACK (“Nack” in S18) and does not reach the specified number of times (No in S19), and therefore determines whether the quality is satisfied (S20). For example, the HARQ control unit 26 sets the first CQI as “assumed propagation path quality” and the second CQI as “quality of propagation path when packets are actually transmitted”, and compares the two. In this case, since the first CQI is higher (No in S20), the HARQ control unit 26 instructs transmission of a retransmission packet (S22).
  • the terminal 50 again generates and transmits a CQI (third CQI) based on the pilot signal, and transmits a NACK because the retransmission packet cannot be correctly received.
  • the HARQ control unit 26 of the base station 10 performs quality determination (S20).
  • the HARQ controller 26 combines (or sums) the second CQI and the third CQI as “the quality of the propagation path when the packet is actually transmitted”, and the first CQI. Is “assumed propagation path quality” and compared.
  • the HARQ control unit 26 stops retransmission due to excessive quality because the former is higher in value than the latter (No in S20, S21). Even if the quality of the propagation path is sufficient and the base station 10 generates and transmits a transmission packet based on the quality, it is considered that there is a high possibility that the terminal 50 transmits a NACK signal by receiving an erroneous packet, for example. It is.
  • the second and third CQIs are combined because the second error detection unit 61 of the terminal 50 combines the data of the new packet and the retransmission packet, and the error is based on the combined data. This is because of the detection.
  • FIGS. 6A and 6B are diagrams showing another example of packet transmission / reception.
  • the example shown in FIGS. 6A and 6B is an example in which the retransmission of the third retransmission packet is stopped.
  • CQI SNR (Signal to Noise ratio) [dB] and will be described using numerical values.
  • the base station 10 determines whether the quality is satisfactory (S20).
  • the retransmission packet may be transmitted under different conditions from the new packet.
  • the retransmission packet is transmitted by the AMC control unit 27 or the like (S15, S16).
  • the base station 10 Since the base station 10 receives the NACK and does not reach the specified number of times (Nack in S18, No in S19), the base station 10 determines the quality (S20).
  • the base station 10 receives the NACK (“Nack” in S18) and does not reach the specified number of times (No in S19), and thus performs quality determination (S20).
  • the communication quality when the base station 10 transmits the second retransmission packet is the communication quality when the base station 10 transmits the first retransmission packet or the like.
  • the base station 10 transmits a retransmission packet based on the communication quality, considers that the terminal 10 has received an erroneous packet, and does not transmit a retransmission packet even if a NACK is received. ing.
  • CQI SIR is an example, and SINR (Signal to Interference and Noise Ratio), CINR (Carrier to Interference plus Noise Ratio) may be used.
  • the base station 10 may notify the upper layer (or upper device) to that effect.
  • the upper layer or the like also holds the packet data of the retransmitted packet, and by performing the notification, for example, the held packet data can be cleared and the processing efficiency can be improved.
  • FIG. 7 is a flowchart illustrating an example of processing
  • FIG. 8 is a diagram illustrating a configuration example of the base station 10.
  • the ARQ retransmission control unit 29 is shown as an example of the upper layer.
  • the ARQ retransmission control unit 29 is a 3GPP RLC (Radio).
  • Radio Radio
  • the HARQ control unit 26 indicates that the retransmission has been stopped if the quality is satisfactory (Yes in S20). This is notified to the unit 29 (S30). Then, the HARQ control unit 26 stops transmission of the retransmission packet (S21).
  • the base station 10 can also transmit a retransmission packet to the terminal 50 as a new packet. If the terminal 50 erroneously stores the packet data addressed to another terminal in the buffer 59, the terminal 50 transmits NACK many times even if the retransmission packet is received. However, when the terminal 50 receives a new packet, the second error detection unit 61 clears the buffer 59, thereby storing error-free packet data.
  • FIG. 9 is a flowchart showing an operation example of this example.
  • the AMC control unit 27 checks whether or not there is packet data for transmitting a retransmission packet as a new packet (S40). For example, if the retransmission packet data is stored in the buffer 13, the AMC control unit 27 determines that a new packet exists (“Yes” in S 40), and proceeds to S 15. Alternatively, the AMC control unit 27 may confirm the presence / absence of a new packet by a notification from an upper layer.
  • the AMC control unit 27 proceeds to the process of S12. If the quality is satisfactory (Yes in S20), the HARQ control unit 26 stops transmitting the retransmission packet, and transmits the retransmission packet as a new packet (S41).
  • the terminal 50 may measure the quality of the pilot signal used when demodulating the packet data, and transmit it to the base station 10 as the CQI.
  • FIG. 10A and FIG. 10B are diagrams illustrating an example of packet transmission / reception.
  • the frequency band is wider than other wireless communication systems, and the pilot signal transmission band is divided into a plurality of frequency regions (in the example of FIG. 10A, five).
  • the terminal 50 measures the quality of the propagation path for each region, generates a CQI corresponding to each, and transmits the CQI to the base station 10.
  • the base station 10 transmits a new packet using the frequency domain corresponding to the CQI with the highest quality among the areas.
  • the terminal 50 receives the new packet and measures the CQI.
  • the terminal 50 measures the CQI of the frequency band (second area in FIG. 10A) used for transmitting the new packet. Like that.
  • the terminal 50 only needs to measure the quality for a part of the frequency bands and transmit the quality information as CQI. Therefore, compared with the case where the quality is measured for all bands, the processing is reduced and the increase in power is prevented. Etc. can be achieved.
  • the AMC control unit 27 of the base station 10 determines which frequency group has the best CQI based on the determination result from the CQI determination unit 25 and includes information indicating which group is used in the control information. Then, the information is transmitted to the terminal 50. Then, the control information analysis unit 56 of the terminal 50 outputs information indicating which group is used to the CQI generation unit 62 via the demodulation unit 57, and the CQI generation unit 62 measures the CQI using the information. To do.
  • the third embodiment is an example of the uplink direction in which packet data is transmitted from the terminal 50 toward the base station 10.
  • the transmitting station device is the terminal 50 and the receiving station device is the base station 10.
  • FIG. 11 is a diagram illustrating a configuration example of the terminal 50
  • FIG. 12 is a diagram illustrating a configuration example of the base station 10.
  • the terminal 50 includes an error detection encoding unit 70, an error correction encoding unit 71, a buffer 72, a third modulation unit 73, a pilot signal generation unit 74, a fourth modulation unit 75, and a radio transmission unit.
  • 76 transmission antenna 77, reception antenna 80, radio reception unit 81, demodulation unit 82, ACK / NACK determination unit 83, HARQ control unit 84, grant determination unit 85, and AMC control unit 86.
  • the transmission unit 110 in the first embodiment corresponds to the transmission antenna 77 from the error detection encoding unit 70
  • the reception unit 120 corresponds to the AMC control unit 86 from the reception antenna 80.
  • the error detection encoding unit 70 detects an error in the packet data transmitted to the base station 10 and performs encoding. When the packet data is new, the error detection encoding unit 70 outputs the packet data so that the packet size is determined by the AMC control unit 86.
  • the error correction coding unit 71 performs coding by performing error correction on the packet data subjected to error detection if there is an error. Encoding is performed at the encoding rate determined by the AMC control unit 86.
  • Buffer 72 stores packet data that has been subjected to error correction.
  • the stored packet data is read from the buffer 72 according to the bit pattern determined by the AMC control unit 86.
  • the third modulator 73 modulates the packet data read from the buffer 72.
  • the third modulator 73 modulates the packet data based on the modulation scheme determined by the AMC controller 86.
  • the pilot signal generator 74 generates a pilot signal to be transmitted from the terminal 50.
  • the fourth modulator 75 modulates the pilot signal.
  • the wireless transmission unit 76 amplifies the packet data from the third modulation unit 73 and the pilot signal from the fourth modulation unit 75 according to the transmission power determined by the AMC control unit 86, and converts the data into a radio signal To do.
  • the transmission antenna 77 transmits a radio signal to the base station 10.
  • the receiving antenna 80 receives a radio signal transmitted from the base station 10.
  • the radio signal includes ACK or NACK and grant.
  • the grant includes various pieces of information such as a packet size, a modulation scheme, a coding rate, a transmission bit pattern, and the like with respect to uplink packet data.
  • the radio reception unit 81 converts the signal before the radio signal conversion in the base station 10.
  • the demodulator 82 demodulates the output of the radio receiver 81, and outputs the demodulated ACK or NACK to the ACK / NACK determination unit 83 and the demodulated grant to the grant determination unit 85.
  • the ACK / NACK determination unit 83 determines whether the output from the demodulation unit 82 is ACK or NACK, and outputs the determination result to the HARQ control unit 84.
  • the HARQ control unit 84 instructs the AMC control unit 86 to transmit a new packet when an ACK is input from the ACK / NACK determination unit 83, and instructs the AMC control unit 86 to retransmit the packet when a NACK is input. .
  • the grant determination unit 85 extracts information such as a packet size included in the grant and outputs the information to the AMC control unit 86.
  • the AMC control unit 86 outputs the packet size from the grant determination unit 85 to the error detection encoding unit 70 when the transmission of a new packet is instructed from the HARQ control unit 84, and the coding rate, transmission bit pattern, modulation method Are output to the error correction encoding unit 71, the buffer 72, and the third modulation unit 73, respectively.
  • the AMC control unit 86 outputs the coding rate from the grant determination unit 85 to the error correction coding unit 71 and the like.
  • the buffer 72 stores packet data for transmitting retransmission packet data until an instruction is given from the AMC control unit 86, for example.
  • the base station 10 includes a reception antenna 32, a radio reception unit 33, a demodulation unit 34, a synthesis unit 35, a buffer 36, an error correction decoding unit 37, an error detection unit 38, a quality measurement unit 39, A grant generation unit 40, an ACK / NACK generation unit 41, a modulation unit 42, a radio transmission unit 43, and a transmission antenna 44 are provided.
  • the receiving unit 210 in the first embodiment corresponds to the error detecting unit 38 from the receiving antenna 32
  • the control unit 230 corresponds to the quality measuring unit 39
  • the transmitting unit 220 from the grant generating unit 40 to the transmitting antenna 44.
  • the receiving antenna 32 receives a radio signal transmitted from the terminal 50.
  • the radio signal includes packet data of a new packet or retransmission packet, a pilot signal, or the like.
  • the radio reception unit 33 converts the radio signal from the reception antenna 32 into data before radio signal conversion in the terminal 50.
  • the demodulator 34 demodulates the output from the radio receiver 33 and outputs the demodulated packet data to the combiner 35 and the demodulated pilot signal to the quality measurer 39.
  • the demodulator 34 performs demodulation based on the modulation scheme determined by the quality measurement unit 39.
  • the synthesis unit 35 When the demodulated packet data is new packet data, the synthesis unit 35 outputs the data to the buffer 36 and the error correction decoding unit 37. In addition, when the demodulated packet data is retransmission packet data, the combining unit 35 combines the data and the packet data stored in the buffer 36 and outputs the combined data to the error correction decoding unit 37 and the buffer 36.
  • the synthesizer 35 synthesizes by the synthesis method determined by the quality measuring unit 39.
  • the buffer 36 stores the packet data output from the combining unit 35.
  • the stored packet data is cleared when the error detecting unit 38 detects that there is no error.
  • the error correction decoding unit 37 performs error correction on the packet data output from the combining unit 35 and decodes the packet data.
  • the error correction decoding unit 37 performs decoding based on the coding rate determined by the quality measurement unit 39.
  • the error detection unit 38 detects whether or not there is an error in the decoded packet data. For example, the error detection unit 38 determines that there is an error in the packet data when the error correction decoding unit 37 performs error correction, and otherwise determines that there is no error.
  • the packet data after error detection is output to another processing unit of the base station 10.
  • the quality measuring unit 39 measures the quality in the uplink direction based on the demodulated pilot signal and generates quality information corresponding to CQI. For example, the quality measuring unit 39 estimates the uplink communication quality from this quality information. Then, the quality measuring unit 39 determines a modulation scheme, a coding rate, a packet size, and the like when the terminal 50 transmits a packet based on the quality information, and the demodulating unit 34, error correction decoding, and the like. Output to the unit 37 and also to the grant generation unit 40. Further, the quality measuring unit 39 performs the quality determination based on the quality information and the detection result from the error detecting unit 38 as in the second embodiment. Details of the quality determination will be described later. As a result of the quality measurement, the quality measurement unit 39 instructs the ACK / NACK generation unit 41 whether there is a retransmission request. The quality measurement unit 39 is also a control unit that controls retransmission.
  • the grant generation unit 40 generates a grant based on information from the quality measurement unit 39.
  • the grant includes a packet size, a modulation scheme, a coding rate, and the like.
  • the ACK / NACK generation unit 41 generates ACK or NACK based on an instruction from the quality measurement unit 39.
  • the ACK / NACK generation unit 41 generates an ACK when an instruction indicating no retransmission request is received from the quality measurement unit 39, for example. Further, the ACK / NACK generation unit 41 generates a NACK, for example, when receiving an instruction for retransmission request from the quality measurement unit 39.
  • the modulation unit 42 modulates ACK or NACK from the ACK / NACK generation unit 41 or grant from the grant generation unit 40.
  • the wireless transmitter 43 amplifies the modulated ACK or the like and converts it to a wireless signal.
  • the transmission antenna 44 transmits a radio signal.
  • FIG. 13 shows an operation example in the third embodiment, which is mainly performed by the quality measuring unit 39 of the base station 10 or the like.
  • the base station 10 receives the pilot signal transmitted from the terminal 50, and the quality measuring unit 39 calculates quality information corresponding to CQI based on the pilot signal (S51).
  • the quality measurement unit 39 determines whether there is a retransmission request based on the error detection result from the error detection unit 38 (S52). For example, the quality measurement unit 39 determines that there is a retransmission request when the detection result has an error, and determines that there is no retransmission request when the detection result has no error.
  • the quality measuring unit 39 determines whether there is a new packet (S53). For example, the quality measuring unit 39 determines that there is a new packet if the data of the new packet is stored in the buffer 36, and determines that there is no new packet otherwise. If there is no new packet (“No” in S53), the process proceeds to S51.
  • the quality measurement unit 39 determines the packet size based on the quality information equivalent to CQI (S54), and determines the modulation method and coding rate (S55).
  • the quality measuring unit 39 performs the process of S55 without performing the process of S54.
  • the grant generation unit 40 generates a grant including each information such as a packet size, a modulation scheme, and a coding rate, and transmits the grant to the terminal 50 via the modulation unit 42 and the like (S56).
  • the terminal 50 generates a new packet or a retransmission packet based on the grant and transmits it to the base station 10.
  • the base station 10 receives each data of a new packet or a retransmission packet transmitted from the terminal 50 (S57).
  • the received data is output to the synthesis unit 35 via the wireless reception unit 33 and the like.
  • the combining unit 35 combines and outputs the packet data if it is stored in the buffer 36, and outputs the packet data if it is not stored.
  • the packet data is output to the error detection unit 38 via the error correction decoding unit 37.
  • the error detection unit 38 detects whether or not there is an error in the received packet data (S58).
  • the error detection unit 38 detects that there is no error in the packet data (“correct” in S58)
  • it clears the packet data stored in the buffer 36 and outputs to the ACK / NACK generation unit 41 that there is no error.
  • the ACK / NACK generation unit 41 generates an ACK and transmits it to the terminal 50 via the modulation unit 42 and the like (S61).
  • the error measurement unit 38 when the error detection unit 38 detects that there is an error in the packet data (“error” in S58), the error measurement unit 38 notifies the quality measurement unit 39 to that effect, and the quality measurement unit 39 sets the number of retransmissions to a threshold (specified number). It is determined whether or not (S59).
  • the quality measurement unit 39 may count elapsed time such as after receiving a new packet (or after transmitting a NACK) instead of the number of retransmissions and determine whether or not a threshold (specified time) has been exceeded.
  • the quality measurement unit 39 instructs the ACK / NACK generation unit 41 to generate ACK, and ACK is transmitted from the base station 10 (S61).
  • the number of retransmissions for example, the number of times the quality measurement unit 39 has instructed the ACK / NACK generation unit 41 may be counted.
  • the quality measuring unit 39 determines the quality (S60). Similarly to the HARQ control unit 26 of the second embodiment, the quality measurement unit 39 compares “assumed propagation path quality” with “propagation channel quality when packets are actually transmitted”.
  • the base station 10 does not normally receive the packet data (other data in the buffer 36 of the base station 10). There is a high possibility that data addressed to the base station is stored.
  • the packet data received so far and the retransmission packet are combined by the combining unit 35, and the error detection unit 38 performs error detection on the combined data. For example, when the new packet data received by the base station 10 is incorrect data, the base station 10 repeats the retransmission request even if the retransmission packet is transmitted from the terminal 50 with high quality.
  • the quality measuring unit 39 determines that the packet has been transmitted with excessive quality when the “quality of the propagation path when the packet is actually transmitted” is higher than the “assumed propagation path quality”. The retransmission request is stopped even if it has not reached. Compared with the case where the retransmission request is repeated until the specified number of times is reached, the wireless communication system 1 can prevent the delay time from increasing and can effectively use the radio resources.
  • the quality measurement unit 39 Since the quality measurement unit 39 generates quality information equivalent to CQI, the quality information is assumed to be a value equivalent to CQI, and “the quality of the assumed propagation path” and “the propagation path when the packet is actually transmitted”. Quality ".
  • the quality measurement unit 39 determines NACK generation as ACK / NACK.
  • the generation unit 41 is instructed (S62). Thereafter, the process proceeds to S51 and the above-described process is repeated.
  • FIG. 14A and FIG. 14B are diagrams showing examples of transmission / reception of packets and the like.
  • the examples shown in these drawings show examples in which transmission of the third retransmission packet is stopped.
  • the pilot signal generator 74 of the terminal 50 generates a pilot signal and transmits it to the base station 10.
  • the base station 10 receives the pilot signal, and the quality measuring unit 39 calculates quality information corresponding to CQI based on the received pilot signal (S51 in FIG. 13).
  • the quality measurement unit 39 Since there is no retransmission request from the error detection unit 38 (“No” in S52) and no packet data is stored in the buffer 36, the quality measurement unit 39 considers that there is a new packet (“Yes” in S53) and corresponds to the CQI.
  • the packet size and the like are determined based on the quality information (first time). (S54 to S55).
  • the grant generation unit 40 generates and transmits grant (first time) including the determined packet size and the like (S56).
  • the terminal 50 generates a new packet based on the packet size, coding rate, etc. included in the grant, and transmits it to the base station 10.
  • the base station 10 receives a new packet and a pilot signal when the terminal 50 transmits the new packet.
  • the quality measuring unit 39 generates quality information (second time) equivalent to CQI based on the pilot signal, and determines the modulation method and the like (S51 to S52, S55).
  • the grant generation unit 40 generates grant (second grant) and transmits it to the terminal 50 (S56).
  • the quality measuring unit 39 detects the error of the new packet by the error detecting unit 38 (“false” in S58), and the quality determination is performed because the number of retransmissions has not reached the threshold (specified number) (No in S59) ( S60).
  • the quality measuring unit 39 sets the quality information equivalent to the first CQI as “assumed propagation path quality” and the quality information equivalent to the second CQI as “quality of the propagation path when the packet is actually transmitted”. Both are compared in the same manner as in the example. In this case, the quality measuring unit 39 instructs the ACK / NACK generating unit 41 to make a retransmission request because the former is a higher numerical value than the latter (No in S60) (S62). From the base station 10, NACK and second grant are transmitted to the terminal 50.
  • the terminal 50 modulates the retransmission packet based on the second grant, and transmits the retransmission packet (first time).
  • the base station 10 receives the retransmission packet (first time) and also receives the pilot signal when the terminal 50 transmits the retransmission packet.
  • the quality measurement unit 39 generates quality information (third time) corresponding to CQI based on the pilot signal, and determines the modulation method and the like (S51 to S52, S55).
  • generation part 40 produces
  • the quality measurement unit 39 performs quality determination because there is an error in the retransmission packet (“false” in S58) and the number of retransmissions has not reached the specified number (No in S59) (S60).
  • the quality measuring unit 39 for example, “assumed propagation path quality” for the quality information equivalent to the first CQI, and “the actual transmission of the packet” is a combination of the quality information equivalent to the second and third CQI. Both are compared as "the quality of the propagation path".
  • the expression (1) is used as in the second embodiment.
  • the quality information is synthesized because error detection by the error detection unit 38 is performed based on the data synthesized by the synthesis unit 35. In this example, since the former is higher than the latter (No in S60), the quality measuring unit 39 instructs a retransmission request (second time) (S62).
  • the base station 10 transmits NACK (second time) and third time grant to the terminal 50.
  • the terminal 50 modulates the retransmission packet (second time) based on the third time grant, and transmits it to the base station 10.
  • the base station 10 receives the retransmission packet and also receives a pilot signal when the terminal 50 transmits the retransmission packet.
  • the quality measuring unit 39 generates quality information (fourth) equivalent to CQI based on the pilot signal (S51).
  • the grant generation unit 40 generates grant (fourth time) and transmits it to the base station 10 (S52, S55 to S56).
  • the quality measuring unit 39 performs the quality determination (S60) because there is an error in the retransmission packet (“false” in S58) and the number of retransmissions has not reached the specified number (No in S59).
  • the quality measuring unit 39 for example, combines the quality information equivalent to the first CQI with “assumed propagation path quality” and the quality information equivalent to the second to fourth CQI with “actual transmission of packet”. Both are compared as "the quality of the propagation path at the time.” In this case, since the latter is higher than the former, the quality measuring unit 39 instructs the ACK transmission without making a retransmission request because the quality is excessive (Yes in S60, S61). For example, in this case, the quality measuring unit 39 may clear the buffer 36. An ACK is transmitted from the base station 10. As for the quality determination, a combination of quality information corresponding to the first to third CQIs may be set as “assumed propagation path quality”.
  • the terminal 50 Since the ACK is returned, the terminal 50 stops sending the retransmission packet.
  • the base station 10 may notify the higher layer (or higher device) 45 that a retransmission request is not made, as shown in FIG. Further, the quality measuring unit 39 may generate the quality information using the frequency band used when the terminal 50 transmits the packet among the divided frequency bands (FIG. 10).

Landscapes

  • Engineering & Computer Science (AREA)
  • Quality & Reliability (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Detection And Prevention Of Errors In Transmission (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

Provided is a radio communication system including a transmission station device and a reception station device between which a radio communication is performed. The transmission station device includes: a transmission unit which transmits packet data to the reception station device; and a reception unit which receives from the reception station device, a response signal indicating that the packet data has not been normally received. The reception station device includes: a reception unit which receives the packet data; and a transmission unit which generates the response signal when the packet data is not normally received and transmits the signal to the transmission station device. The transmission station device or the reception station device includes a control unit which estimates a communication quality when the packet data is transmitted or received. If the estimated communication quality is higher than a required quality, the control unit performs control so that the packet data is not retransmitted even when the response signal is received or the packet data cannot be normally received.

Description

無線通信システム、送信局装置、受信局装置、及び無線通信システムにおける無線通信方法Wireless communication system, transmitting station apparatus, receiving station apparatus, and wireless communication method in wireless communication system
　本発明は、無線通信システム、送信局装置、受信局装置、及び無線通信システムにおける無線通信方法に関する。 The present invention relates to a radio communication system, a transmission station apparatus, a reception station apparatus, and a radio communication method in the radio communication system.
　従来から、無線通信システムにおいてＡＭＣ（Adaptive Modulation and
Coding）制御と呼ばれる技術がある。例えば、端末装置（ＭＳ：Mobile Station）は下り方向の伝搬路の品質を測定し、品質情報を示すＣＱＩ（Channel
Quality Indicator）を基地局装置（ＢＴＳ：Base Transceiver Station）に送信する。基地局装置は、ＣＱＩに基づいて変調方式と誤り訂正の符号化率を選択する。 Conventionally, AMC (Adaptive Modulation and
There is a technique called control. For example, a terminal apparatus (MS: Mobile Station) measures the quality of a downlink propagation path and indicates CQI (Channel
Quality Indicator) is transmitted to a base station apparatus (BTS: Base Transceiver Station). The base station apparatus selects a modulation scheme and an error correction coding rate based on the CQI.
　また、無線通信システムにおいて、ＨＡＲＱ（Hybrid
Automatic Repeat request）と呼ばれる技術もある（例えば、以下の非特許文献１及び２）。例えば、端末装置は基地局装置から送信される新規パケットを正しく受信できた場合、ＡＣＫ信号を送信し、正しく受信できなかった場合、ＮＡＣＫ信号を送信する。基地局装置は、ＮＡＣＫ信号を受信すると、パケットを再送する。端末装置は再送パケットとこれまで受信したパケットとを合成し、正しく受信できたか否かを判定する。また、基地局装置は、所定時間経過後も、ＮＡＣＫ信号を受信した場合、再送パケットの送信を停止する。 In a wireless communication system, HARQ (Hybrid
There is also a technique called “Automatic Repeat request” (for example, Non-Patent Documents 1 and 2 below). For example, the terminal apparatus transmits an ACK signal when it can correctly receive a new packet transmitted from the base station apparatus, and transmits a NACK signal when it cannot be received correctly. When receiving the NACK signal, the base station apparatus retransmits the packet. The terminal device combines the retransmission packet and the packet received so far, and determines whether or not the packet has been correctly received. Also, the base station device stops transmission of retransmission packets when a NACK signal is received even after a predetermined time has elapsed.
　さらに、受信側からＮＡＣＫ信号を受信した場合、送信側は、再送パケットを送信する際に不足している通信品質を推定し、不足した通信品質を満たすように再送パケットを生成し、受信側に送信するようにしたものも開示される（例えば、以下の特許文献１～４）。　
3GPP TS36.321 V8.3.0 3GPP TS25.321 特開２００２‐９７４１号公報 特開２００３‐２６４８７３号公報 特開２００２‐５１００３号公報 特開２００４‐１１２５９７号公報 Further, when a NACK signal is received from the receiving side, the transmitting side estimates a communication quality that is insufficient when transmitting a retransmission packet, generates a retransmission packet so as to satisfy the insufficient communication quality, and A transmission is also disclosed (for example, Patent Documents 1 to 4 below).
3GPP TS36.321 V8.3.0 3GPP TS25.321 JP 2002-9741 A JP 2003-264873 A Japanese Patent Laid-Open No. 2002-5003 JP 2004-112597 A
　しかし、上述した特許文献に開示されたものは、通信品質が不足していない場合で、さらに送信側が受信側からＮＡＣＫを受信した場合に、送信側がどのように処理を行うかは考慮されていない。 However, what is disclosed in the above-mentioned patent document is a case where communication quality is not insufficient, and when the transmission side receives NACK from the reception side, how the transmission side performs processing is not considered. .
　また、基地局装置がＨＡＲＱによる再送制御を行う場合、基地局装置が再送パケットの送信を所定時間経過後に停止すると、所定時間分だけその後の処理に遅延が生じる。この場合、基地局装置は所定時間内に再送パケットを繰り返し送信しているため、無線リソースが無駄に使用される。 In addition, when the base station apparatus performs retransmission control by HARQ, if the base station apparatus stops transmission of the retransmission packet after a predetermined time has elapsed, the subsequent processing is delayed by a predetermined time. In this case, since the base station apparatus repeatedly transmits retransmission packets within a predetermined time, radio resources are wasted.
　そこで、本発明の目的の一つは、遅延防止を図るようにした無線通信システム、送信局装置、受信局装置、及び無線通信システムを提供することにある。 Therefore, one of the objects of the present invention is to provide a wireless communication system, a transmitting station apparatus, a receiving station apparatus, and a wireless communication system that are designed to prevent delay.
　また、本発明の他の目的の一つは、無線リソースを有効活用した無線通信システム等を提供することにある。　 Also, another object of the present invention is to provide a wireless communication system or the like that effectively uses wireless resources. *
　一態様によれば、送信局装置と受信局装置との間で無線通信を行う無線通信システムにおいて、前記送信局装置は、パケットデータを前記受信局装置に送信する送信部と、前記パケットデータが正しく受信できなかったことを示す応答信号を前記受信局装置から受信する受信部とを備え、前記受信局装置は、前記パケットデータを受信する受信部と、前記パケットデータを正しく受信できなかったとき前記応答信号を生成して前記送信局装置に送信する送信部とを備え、前記送信局装置または前記受信局装置は、前記パケットデータをそれぞれ送信または受信したときの通信品質を推定し、推定した前記通信品質が所要品質よりも高いとき、それぞれ前記応答信号を受信したときまたは正しく前記パケットデータを受信できないときでも前記パケットデータの再送を行わないように制御する制御部を備える。 According to an aspect, in a wireless communication system that performs wireless communication between a transmission station apparatus and a reception station apparatus, the transmission station apparatus includes a transmission unit that transmits packet data to the reception station apparatus, and the packet data A receiving unit that receives from the receiving station device a response signal indicating that the packet was not correctly received, and the receiving station device received the packet data and when the packet data could not be received correctly A transmission unit that generates the response signal and transmits the response signal to the transmission station apparatus, and the transmission station apparatus or the reception station apparatus estimates and estimates communication quality when the packet data is transmitted or received, respectively. When the communication quality is higher than the required quality, even when the response signal is received or when the packet data cannot be received correctly, A control unit for controlling so as not to perform retransmission of the packet data.
　また、他の態様によれば、受信局装置との間で無線通信を行う送信局装置において、パケットデータを前記受信局装置に送信する送信部と、前記パケットデータが正しく受信できなかったことを示す応答信号を前記受信局装置から受信する受信部と、前記パケットデータを送信したときの通信品質を推定し、推定した前記通信品質が所要品質よりも高いとき、前記応答信号を受信したときでも前記パケットデータの再送を行わないように制御する制御部とを備える。 According to another aspect, in the transmitting station apparatus that performs wireless communication with the receiving station apparatus, the transmitting unit that transmits packet data to the receiving station apparatus, and the packet data cannot be received correctly A receiving unit that receives a response signal indicating from the receiving station device, and a communication quality when the packet data is transmitted, and when the estimated communication quality is higher than a required quality, even when the response signal is received And a control unit that controls not to retransmit the packet data.
　さらに、他の態様によれば、送信局装置との間で無線通信を行う受信局装置において、前記送信局装置から送信されたパケットデータを受信する受信部と、前記パケットデータを正しく受信できなかったとき前記応答信号を生成して前記送信局装置に送信する送信部と、前記パケットデータを受信したときの通信品質を推定し、推定した前記通信品質が所要品質よりも高いとき、前記パケットデータを正しく受信できなかったときでも前記パケットデータの再送を行わないように制御する制御部とを備える。 Furthermore, according to another aspect, in a receiving station apparatus that performs radio communication with a transmitting station apparatus, a receiving unit that receives packet data transmitted from the transmitting station apparatus, and the packet data cannot be received correctly A transmission unit that generates the response signal and transmits the response signal to the transmitting station device, and estimates the communication quality when the packet data is received. When the estimated communication quality is higher than the required quality, the packet data And a control unit that controls not to retransmit the packet data even when the packet data cannot be correctly received.
　さらに、他の態様によれば、送信局装置と受信局装置との間で無線通信を行う無線通信システムにおける無線通信方法であって、前記送信局装置は、パケットデータを前記受信局装置に送信し、前記受信局装置は、前記パケットデータを正しく受信できなかったとき、正しく受信できなかったことを示す応答信号を生成して前記送信局装置に送信し、前記送信局装置は、前記応答信号を前記受信局装置から受信し、前記送信局装置または前記受信局装置は、前記パケットデータをそれぞれ送信または受信したときの通信品質を推定し、推定した前記通信品質が所要品質よりも高いとき、それぞれ前記応答信号を受信したときまたは正しく前記パケットデータを正しく受信できないときでも前記パケットデータの再送を行わないように制御する。 Furthermore, according to another aspect, there is provided a wireless communication method in a wireless communication system that performs wireless communication between a transmitting station device and a receiving station device, wherein the transmitting station device transmits packet data to the receiving station device. When the reception station apparatus cannot correctly receive the packet data, the reception station apparatus generates a response signal indicating that the packet data has not been correctly received and transmits the response signal to the transmission station apparatus. From the receiving station device, the transmitting station device or the receiving station device estimates the communication quality when transmitting or receiving the packet data, respectively, and when the estimated communication quality is higher than the required quality, Control is performed so that the packet data is not retransmitted even when the response signal is received or when the packet data cannot be received correctly. .
　遅延防止を図るようにした無線通信システム、送信局装置、受信局装置、及び無線通信システムを提供できる。また、無線リソースを有効活用した無線通信システム等を提供できる。 It is possible to provide a wireless communication system, a transmitting station device, a receiving station device, and a wireless communication system that can prevent delay. In addition, it is possible to provide a wireless communication system that effectively uses wireless resources.
図１は無線通信システムの構成例を示す図である。FIG. 1 is a diagram illustrating a configuration example of a wireless communication system. 図２は送信局装置（基地局装置）の構成例を示す図である。FIG. 2 is a diagram illustrating a configuration example of a transmission station apparatus (base station apparatus). 図３は受信局装置（端末装置）の構成例を示す図である。FIG. 3 is a diagram illustrating a configuration example of a receiving station device (terminal device). 図４は動作例を示すフローチャートである。FIG. 4 is a flowchart showing an operation example. 図５（Ａ）及び同図（Ｂ）はパケット等の送受信例を示す図である。FIG. 5A and FIG. 5B are diagrams showing examples of transmission / reception of packets and the like. 図６（Ａ）及び同図（Ｂ）はパケット等の送受信例を示す図である。FIG. 6A and FIG. 6B are diagrams showing examples of transmission / reception of packets and the like. 図７は動作例を示すフローチャートである。FIG. 7 is a flowchart showing an operation example. 図８は送信局装置（基地局装置）の構成例を示す図である。FIG. 8 is a diagram illustrating a configuration example of a transmission station apparatus (base station apparatus). 図９は動作例を示すフローチャートである。FIG. 9 is a flowchart showing an operation example. 図１０（Ａ）及び同図（Ｂ）はパケット等の送受信例を示す図である。FIG. 10A and FIG. 10B are diagrams showing examples of transmission / reception of packets and the like. 図１１は送信局装置（端末装置）の構成例を示す図である。FIG. 11 is a diagram illustrating a configuration example of a transmission station apparatus (terminal apparatus). 図１２は受信局装置（基地局装置）の構成例を示す図である。FIG. 12 is a diagram illustrating a configuration example of a receiving station apparatus (base station apparatus). 図１３は動作例を示すフローチャートである。FIG. 13 is a flowchart showing an operation example. 図１４（Ａ）及び同図（Ｂ）はパケット等の送受信例を示す図である。FIG. 14A and FIG. 14B are diagrams showing examples of transmission / reception of packets and the like. 図１５は受信局装置（基地局装置）の構成例を示す図である。FIG. 15 is a diagram illustrating a configuration example of a receiving station apparatus (base station apparatus).
符号の説明Explanation of symbols
１：無線通信システム　　　　　　　　　１０：基地局装置（送信局装置または受信局装置）
１１：第１の誤り検出符号化部　　　　　１２：第１の誤り訂正符号化部
１３：バッファ　　　　　　　　　　　　１４：第１の変調部
１５：第２の誤り検出符号化部　　　　　１６：第２の誤り訂正符号化部
１７：第２の変調部　　　　　　　　　　２４：ＡＣＫ／ＮＡＣＫ判定部
２５：ＣＱＩ判定部　　　　　　　　　　２６：ＨＡＲＱ制御部
２７：ＡＭＣ制御部　　　　　　　　　　２９：ＲＬＣ部
３４：復調部　　　　　　　　　　　　　３５：合成部
３６：バッファ　　　　　　　　　　　　３７：誤り訂正復号化部
３８：誤り検出部　　　　　　　　　　　３９：品質測定部
４０：ｇｒａｎｔ生成部　　　　　　　　４１：ＡＣＫ／ＮＡＣＫ生成部
５０：端末装置（受信局装置または送信局装置）
５３：第１の復調部　　　　　　　　　　５４：第１の誤り訂正復号化部
５５：第１の誤り検出部　　　　　　　　５６：制御情報解析部
５７：第２の復調部　　　　　　　　　　５８：合成部
５９：バッファ　　　　　　　　　　　　６０：第２の誤り訂正復号化部
６１：第２の誤り検出部　　　　　　　　６２：ＣＱＩ生成部　
６３：ＡＣＫ／ＮＡＣＫ生成部　　　　　６４：変調部　
７０：誤り検出符号化部　　　　　　　　７１：誤り訂正符号化部
７２：バッファ　　　　　　　　　　　　７３：第３の変調部
７４：パイロット信号発生部　　　　　　７５：第４の変調部
８２：復調部　　　　　　　　　　　　　８３：ＡＣＫ／ＮＡＣＫ判定部
８４：ＨＡＲＱ制御部　　　　　　　　　８５：ｇｒａｎｔ判定部
８６：ＡＭＣ制御部 1: Wireless communication system 10: Base station apparatus (transmitting station apparatus or receiving station apparatus)
11: First error detection encoding unit 12: First error correction encoding unit 13: Buffer 14: First modulation unit 15: Second error detection encoding unit 16: Second error correction encoding unit 17: Second modulation unit 24: ACK / NACK determination unit 25: CQI determination unit 26: HARQ control unit 27: AMC control unit 29: RLC unit 34: demodulation unit 35: synthesis unit 36: buffer 37: error correction decoding Unit 38: Error detecting unit 39: Quality measuring unit 40: Grant generating unit 41: ACK / NACK generating unit 50: Terminal device (receiving station device or transmitting station device)
53: First demodulator 54: First error correction decoder 55: First error detector 56: Control information analyzer 57: Second demodulator 58: Synthesizer 59: Buffer 60: Second Error correction decoder 61: second error detector 62: CQI generator
63: ACK / NACK generator 64: Modulator
70: Error detection encoding unit 71: Error correction encoding unit 72: Buffer 73: Third modulation unit 74: Pilot signal generation unit 75: Fourth modulation unit 82: Demodulation unit 83: ACK / NACK determination unit 84: HARQ control unit 85: grant determination unit 86: AMC control unit
　本発明を実施するための形態について以下説明する。 DETAILED DESCRIPTION Embodiments for carrying out the present invention will be described below.
　＜第１の実施例＞
　第１の実施例について説明する。図１は無線通信システム１の構成例を示す図である。送信局装置１００と受信局装置２００との間で無線通信を行う無線通信システム１において、前記送信局装置１００は、パケットデータを前記受信局装置２００に送信する送信部１１０と、前記パケットデータが正しく受信できなかったことを示す応答信号を前記受信局装置２００から受信する受信部１２０とを備え、前記受信局装置２００は、前記パケットデータを受信する受信部と２１０、前記パケットデータを正しく受信できなかったとき前記応答信号を生成して前記送信局装置１００に送信する送信部２２０とを備え、前記送信局装置１００または前記受信局装置２００は、前記パケットデータをそれぞれ送信または受信したときの通信品質を推定し、推定した前記通信品質が所要品質よりも高いとき、それぞれ前記応答信号を受信したときまたは正しく前記パケットデータを受信できないときでも前記パケットデータの再送を行わないように制御する制御部１３０（２３０）を備える。 <First embodiment>
A first embodiment will be described. FIG. 1 is a diagram illustrating a configuration example of a wireless communication system 1. In the wireless communication system 1 that performs wireless communication between the transmission station apparatus 100 and the reception station apparatus 200, the transmission station apparatus 100 includes a transmission unit 110 that transmits packet data to the reception station apparatus 200, and the packet data A receiving unit 120 that receives from the receiving station device 200 a response signal indicating that the packet has not been correctly received. The receiving station device 200 receives the packet data and 210, and receives the packet data correctly. A transmission unit 220 that generates the response signal and transmits the response signal to the transmitting station device 100 when the packet data cannot be transmitted, and the transmitting station device 100 or the receiving station device 200 transmits or receives the packet data, respectively. Estimate communication quality, and receive the response signal when the estimated communication quality is higher than the required quality It comprises any control unit 130 for controlling so as not to perform retransmission of the packet data (230) when or not received correctly the packet data when the.
　送信局装置１００の送信部１１０はパケットデータを送信する。受信局装置の受信部２１０はパケットデータを受信し、送信部２２０はパケットデータを正しく受信できなかったとき、正しく受信できなかったことを示す応答信号を送信する。 The transmitting unit 110 of the transmitting station device 100 transmits packet data. The receiving unit 210 of the receiving station apparatus receives the packet data, and the transmitting unit 220 transmits a response signal indicating that the packet data was not correctly received when the packet data was not correctly received.
　送信局装置１００の受信部１２０は、応答信号を受信する。例えば制御部１３０が送信局装置１００にあるときは以下のようになる。制御部１３０は、送信部１１０からパケットデータを送信したときの通信品質を推定し、その通信品質が所要品質より高かったとき、前記応答信号を受信してもパケットデータの再送を行わないように制御する。 The receiving unit 120 of the transmitting station device 100 receives the response signal. For example, when the control unit 130 is in the transmitting station device 100, the operation is as follows. The control unit 130 estimates the communication quality when the packet data is transmitted from the transmission unit 110. When the communication quality is higher than the required quality, the control unit 130 does not retransmit the packet data even if the response signal is received. Control.
　一方、制御部２３０が受信局装置２００にあるときは以下のようになる。制御部２３０は、受信部２１０でパケットデータを受信したときの通信品質を推定し、その通信品質が所要品質より高かったとき、パケットデータを正しく受信できないときでも前記パケットデータの再送を行わないように制御する。 On the other hand, when the control unit 230 is in the receiving station device 200, the operation is as follows. The control unit 230 estimates the communication quality when the reception unit 210 receives the packet data, and when the communication quality is higher than the required quality, the control unit 230 does not retransmit the packet data even when the packet data cannot be correctly received. To control.
　例えば、送信局装置１００は、パケットデータの再送を行わないように制御するため、規定回数または規定時間に達するまでパケットデータを再送する場合と比較して、遅延を防止することができ、また無線リソースを有効活用できる。 For example, since the transmission station apparatus 100 performs control so as not to retransmit the packet data, the transmission station apparatus 100 can prevent delay compared to the case where the packet data is retransmitted until a predetermined number of times or a predetermined time is reached. Effective use of resources.
　また、受信局装置２００は、パケットデータの再送を行わないように制御するため、同様に、遅延防止を図ることができ、また、無線リソースを有効活用できる。 In addition, since the receiving station apparatus 200 performs control so as not to retransmit the packet data, similarly, it is possible to prevent delay and to effectively use radio resources.
　＜第２の実施例＞
　次に第２の実施例について説明する。第２の実施例は、パケットデータ等が基地局装置（以下、基地局）１０から端末装置（以下、端末）５０に向けて送信される下り方向の例である。送信局装置１００が基地局１０、受信局装置２００が端末５０である。図２は無線通信システム１における基地局（送信局装置１００）１０、図３は端末（受信局装置２００）５０の各構成例をそれぞれ示す図である。 <Second Embodiment>
Next, a second embodiment will be described. The second embodiment is an example of a downlink direction in which packet data or the like is transmitted from a base station apparatus (hereinafter referred to as a base station) 10 to a terminal apparatus (hereinafter referred to as a terminal) 50. The transmitting station device 100 is the base station 10 and the receiving station device 200 is the terminal 50. FIG. 2 is a diagram illustrating a configuration example of the base station (transmitting station apparatus 100) 10 in the wireless communication system 1, and FIG.
　基地局１０は、第１の誤り検出符号化部１１と、第１の誤り訂正符号化部１２と、バッファ１３と、第１の変調部１４と、第２の誤り検出符号化部１５と、第２の誤り訂正符号化部１６と、第２の変調部１７と、無線送信部１８と、送信アンテナ１９と、受信アンテナ２１と、無線受信部２２と、復調部２３と、ＡＣＫ／ＮＡＣＫ判定部２４と、ＣＱＩ判定部２５と、ＨＡＲＱ制御部２６と、ＡＭＣ制御部２７とを備える。 The base station 10 includes a first error detection encoding unit 11, a first error correction encoding unit 12, a buffer 13, a first modulation unit 14, a second error detection encoding unit 15, Second error correction coding unit 16, second modulation unit 17, wireless transmission unit 18, transmission antenna 19, reception antenna 21, wireless reception unit 22, demodulation unit 23, and ACK / NACK determination Unit 24, CQI determination unit 25, HARQ control unit 26, and AMC control unit 27.
　第１の実施例における送信部１１０は、例えば、誤り検出符号化部１１から送信アンテナ１９に対応する。また、受信部１２０は、例えば、無線受信部２２からＣＱＩ判定部２５に対応する。さらに、制御部１３０はＨＡＲＱ制御部２６に対応する。 The transmission unit 110 in the first embodiment corresponds to the transmission antenna 19 from the error detection encoding unit 11, for example. In addition, the reception unit 120 corresponds to the CQI determination unit 25 from the wireless reception unit 22, for example. Further, the control unit 130 corresponds to the HARQ control unit 26.
　第１の誤り検出符号化部１１は、パケットデータに対して誤り訂正を行い、符号化を行う。第１の誤り検出符号化部１１は、パケットデータが新規パケットの場合、ＡＭＣ制御部２７により決定されたパケットサイズとなるように当該パケットデータを出力する。 The first error detection encoding unit 11 performs error correction on the packet data and performs encoding. When the packet data is a new packet, the first error detection encoding unit 11 outputs the packet data so that the packet size determined by the AMC control unit 27 is obtained.
　第１の誤り訂正符号化部１２は、第１の誤り検出符号化部１１からの出力に対して、誤りがあれば誤り訂正と符号化を行う。第１の誤り訂正符号化部１２は、ＡＭＣ制御部２７により決定された符号化率に基づいて符号化を行う。 The first error correction encoder 12 performs error correction and encoding on the output from the first error detection encoder 11 if there is an error. The first error correction coding unit 12 performs coding based on the coding rate determined by the AMC control unit 27.
　バッファ１３は、第１の誤り訂正符号化部１２からの符号化されたパケットデータを一時記憶する。記憶されたパケットデータは、ＡＭＣ制御部２７により決定されたビットパターンに従って読みだされる。例えば、バッファ１３は、基地局１０が新規パケットを再送信（以下、再送）するときのためのために、ＡＭＣ制御部２７からの指示があるまで新規パケットのデータを記憶する。 The buffer 13 temporarily stores the encoded packet data from the first error correction encoding unit 12. The stored packet data is read according to the bit pattern determined by the AMC control unit 27. For example, the buffer 13 stores the data of the new packet until an instruction from the AMC control unit 27 is made in order for the base station 10 to retransmit the new packet (hereinafter referred to as retransmission).
　第１の変調部１４は、ＡＭＣ制御部２７で決定された変調方式により、バッファ１３からの出力に対して変調を行う。 The first modulation unit 14 modulates the output from the buffer 13 by the modulation method determined by the AMC control unit 27.
　第２の誤り検出符号化部１５は、ＡＭＣ制御部２７で決定された、パケットサイズ、送信ビットパターン、変調方式、送信電力等を含む制御情報に対して、誤り検出と符号化を行う。制御情報は、例えば、新規パケットと再送パケットのそれぞれに対する制御情報がある。 The second error detection encoding unit 15 performs error detection and encoding on the control information including the packet size, transmission bit pattern, modulation scheme, transmission power, etc. determined by the AMC control unit 27. The control information includes, for example, control information for new packets and retransmission packets.
　第２の誤り訂正符号化部１６は、第２の誤り検出符号化部１５からの出力に対して、誤りがあれば誤り訂正を行い、符号化を行う。 The second error correction encoding unit 16 performs error correction on the output from the second error detection encoding unit 15 and performs encoding if there is an error.
　第２の変調部１７は、第２の誤り訂正符号化部１６からの出力を変調する。 The second modulator 17 modulates the output from the second error correction encoder 16.
　無線送信部１８は、第１及び第２の変調部１４，１７からの出力それぞれに対して、ＡＭＣ制御部２７で決定された送信電力に従って増幅等を行い、無線信号に変換する。例えば、無線送信部１８はパイロット信号（または既知信号）を生成してもよい。 The radio transmission unit 18 performs amplification or the like on the outputs from the first and second modulation units 14 and 17 according to the transmission power determined by the AMC control unit 27, and converts them into radio signals. For example, the wireless transmission unit 18 may generate a pilot signal (or a known signal).
　送信アンテナ１９は、無線送信部１８からの無線信号を端末５０に送信する。基地局１０からは、新規パケットまたは再送パケット、制御情報、及びパイロット信号等が無線信号として端末５０に送信される。なお、制御情報は、各パケットの送信に先立ち、第２の誤り検出符号化部１５等で処理が行われて端末５０に送信される。 The transmission antenna 19 transmits a radio signal from the radio transmission unit 18 to the terminal 50. From the base station 10, new packets or retransmission packets, control information, pilot signals, and the like are transmitted to the terminal 50 as radio signals. Prior to the transmission of each packet, the control information is processed by the second error detection encoding unit 15 and transmitted to the terminal 50.
　受信アンテナ２１は、端末５０から送信されたＡＣＫまたはＮＡＣＫ、及びＣＱＩ等を受信する。 The receiving antenna 21 receives ACK or NACK transmitted from the terminal 50, CQI, and the like.
　復調部２３は、受信アンテナ２１からの出力を復調し、復調されたＡＣＫまたはＮＡＣＫをＡＣＫ／ＮＡＣＫ判定部２４、復調されたＣＱＩをＣＱＩ判定部２５にそれぞれ出力する。 The demodulation unit 23 demodulates the output from the receiving antenna 21 and outputs the demodulated ACK or NACK to the ACK / NACK determination unit 24 and the demodulated CQI to the CQI determination unit 25, respectively.
　ＡＣＫ／ＮＡＣＫ判定部２４は、ＡＣＫまたはＮＡＣＫを判定し、その結果をＨＡＲＱ制御部２６にそれぞれ出力する。 The ACK / NACK determination unit 24 determines ACK or NACK and outputs the result to the HARQ control unit 26.
　ＣＱＩ判定部２５は、ＣＱＩを判定し、判定結果をＨＡＲＱ制御部２６とＡＭＣ制御部２７に出力する。 The CQI determination unit 25 determines the CQI and outputs the determination result to the HARQ control unit 26 and the AMC control unit 27.
　ＨＡＲＱ制御部２６は、ＡＣＫ／ＮＡＣＫ判定部２４からの判定結果と、ＣＱＩ判定部２５からの判定結果とに基づいて、パケットを新規で送信するかまたは再送するか等を判定し、その結果をＡＭＣ制御部２７に通知する。詳細は後述する。ＨＡＲＱ制御部２６は、ＣＱＩ判定部２５からの結果（例えば、ＣＱＩ）に基づいて、例えば、パケットデータを送信したときの通信品質を推定する。 The HARQ control unit 26 determines whether to newly transmit or retransmit a packet based on the determination result from the ACK / NACK determination unit 24 and the determination result from the CQI determination unit 25, and the result is Notify the AMC control unit 27. Details will be described later. The HARQ control unit 26 estimates the communication quality when, for example, packet data is transmitted based on the result (for example, CQI) from the CQI determination unit 25.
　ＡＭＣ制御部２７は、ＣＱＩ判定部２５からの判定結果と、ＨＡＲＱ制御部２６から出力された新規送信または再送信の指示とに基づいて、新規パケットまたは再送パケットに対する制御情報を決定する。ＡＭＣ制御部２７は、決定した送信ビットパターンをバッファ１３、決定した変調方式を第１の変調部１４、決定した送信電力を無線送信部１８にそれぞれ出力する。また、ＡＭＣ制御部２７は、新規パケットを送信する場合、さらに、決定したパケットサイズを誤り検出符号化部１１に出力する。 The AMC control unit 27 determines control information for a new packet or a retransmission packet based on a determination result from the CQI determination unit 25 and a new transmission or retransmission instruction output from the HARQ control unit 26. The AMC control unit 27 outputs the determined transmission bit pattern to the buffer 13, the determined modulation scheme to the first modulation unit 14, and the determined transmission power to the wireless transmission unit 18. Further, when transmitting a new packet, the AMC control unit 27 further outputs the determined packet size to the error detection encoding unit 11.
　次に端末５０の構成例について説明する。端末５０は、受信アンテナ５１と、無線受信部５２と、第１の復調部５３と、第１の誤り訂正復号化部５４と、第１の誤り検出部５５と、制御情報解析部５６と、第２の復調部５７と、合成部５８と、バッファ５９と、第２の誤り訂正復号化部６０と、第２の誤り検出部６１と、ＣＱＩ生成部６２と、ＡＣＫ／ＮＡＣＫ生成部６３と、変調部６４と、無線送信部６５とを備える。 Next, a configuration example of the terminal 50 will be described. The terminal 50 includes a reception antenna 51, a radio reception unit 52, a first demodulation unit 53, a first error correction decoding unit 54, a first error detection unit 55, a control information analysis unit 56, A second demodulator 57, a combiner 58, a buffer 59, a second error correction decoder 60, a second error detector 61, a CQI generator 62, and an ACK / NACK generator 63 , A modulation unit 64 and a wireless transmission unit 65 are provided.
　例えば、第１の実施例における受信部２１０は、受信アンテナ５１から誤り検出部６１に対応し、送信部２２０は、ＣＱＩ生成部６２から送信アンテナ６６に対応する。 For example, the receiving unit 210 in the first embodiment corresponds to the error detecting unit 61 from the receiving antenna 51, and the transmitting unit 220 corresponds to the transmitting antenna 66 from the CQI generating unit 62.
　受信アンテナ５１は、基地局１０から送信された無線信号を受信する。 The receiving antenna 51 receives a radio signal transmitted from the base station 10.
　無線受信部５２は、受信アンテナ５１で受信した無線信号を、基地局１０における無線送信部１８の入力前の信号に変換して出力する。 The radio reception unit 52 converts the radio signal received by the reception antenna 51 into a signal before input of the radio transmission unit 18 in the base station 10 and outputs the signal.
　第１の復調部５３は、無線受信部５２からの出力のうち制御情報を復調する。 The first demodulator 53 demodulates the control information out of the output from the radio receiver 52.
　第１の誤り訂正復号化部５４は、復調された制御情報に対して、誤り訂正を行い、復号化を行う。 The first error correction decoding unit 54 performs error correction and decoding on the demodulated control information.
　第１の誤り検出部５５は、第１の誤り訂正復号化部５４から出力された制御情報に対して、誤り検出を行う。 The first error detection unit 55 performs error detection on the control information output from the first error correction decoding unit 54.
　制御情報解析部５６は、誤り検出後の制御情報を解析し、制御情報に含まれる変調方式、合成の有無及び合成方法、符号化率をそれぞれ第２の復調部５７、合成部５８、及び誤り訂正復号化部６０に出力する。 The control information analysis unit 56 analyzes the control information after error detection, and sets the modulation method, the presence / absence and combination method and the coding rate included in the control information to the second demodulation unit 57, the combination unit 58, and the error rate, respectively. It outputs to the correction decoding part 60.
　第２の復調部５７は、無線受信部５２からの出力に対して、制御情報解析部５６からの変調方式に基づいて復調し、合成部５８に出力する。また、第２の復調部５７は、復調後のパケットデータを合成部５８に、復調後のパイロット信号をＣＱＩ生成部６２にそれぞれ出力する。 The second demodulator 57 demodulates the output from the radio receiver 52 based on the modulation method from the control information analyzer 56 and outputs the demodulated signal to the synthesizer 58. The second demodulator 57 outputs the demodulated packet data to the synthesizer 58 and the demodulated pilot signal to the CQI generator 62.
　合成部５８は、復調後のパケットデータとバッファ５９に記憶されたパケットデータとを合成し、第２の誤り訂正復号化部６０とバッファ５９に出力する。ただし、合成部５８は、復調後のパケットデータが新規パケットデータのときバッファ５９にパケットデータが記憶されていないため、合成することなく第２の誤り訂正復号化部６０とバッファ５９に出力する。例えば、合成部５８はパケットデータが新規か再送かを、制御情報解析部５６からの合成の有無に基づいて判断する。 The synthesizing unit 58 synthesizes the demodulated packet data and the packet data stored in the buffer 59 and outputs them to the second error correction decoding unit 60 and the buffer 59. However, since the packet data is not stored in the buffer 59 when the demodulated packet data is new packet data, the combining unit 58 outputs the packet data to the second error correction decoding unit 60 and the buffer 59 without combining them. For example, the combining unit 58 determines whether the packet data is new or retransmitted based on the presence / absence of combining from the control information analyzing unit 56.
　第２の誤り訂正復号化部６０は、合成部５８から出力されたパケットデータに対して、誤り訂正と復号化を行う。 The second error correction decoding unit 60 performs error correction and decoding on the packet data output from the synthesis unit 58.
　第２の誤り検出部６１は、第２の誤り訂正復号化部６０から出力されたパケットデータに対して、誤り検出を行う。第２の誤り検出部６１は、検出結果をＡＣＫ／ＮＡＣＫ生成部６３に出力する。なお、第２の誤り検出部６１は、誤り検出の結果、誤りがない場合、バッファ５９に記憶されたパケットデータをクリアする。 The second error detection unit 61 performs error detection on the packet data output from the second error correction decoding unit 60. The second error detection unit 61 outputs the detection result to the ACK / NACK generation unit 63. Note that the second error detection unit 61 clears the packet data stored in the buffer 59 when there is no error as a result of the error detection.
　ＣＱＩ生成部６２は、復調後のパイロット信号に基づいて、下り方向のチャネル品質を測定し、品質情報を含むＣＱＩを生成する。 The CQI generation unit 62 measures downlink channel quality based on the demodulated pilot signal and generates CQI including quality information.
　ＡＣＫ／ＮＡＣＫ生成部６３は、第２の誤り検出部６１からの出力に基づいて、応答信号（ＡＣＫまたはＮＡＣＫ）を生成する。例えば、ＡＣＫ／ＮＡＣＫ生成部６３は、第２の誤り検出部６１から誤りがない検出結果を得たとき（または正しくパケットデータを受信できたとき）、ＡＣＫを生成する。また、ＡＣＫ／ＮＡＣＫ生成部６３は、誤りがある検出結果を得たとき（または正しくパケットデータを受信できなかったとき）、ＮＡＣＫ（再送要求）を生成する。 The ACK / NACK generation unit 63 generates a response signal (ACK or NACK) based on the output from the second error detection unit 61. For example, the ACK / NACK generation unit 63 generates an ACK when obtaining a detection result with no error from the second error detection unit 61 (or when packet data has been correctly received). The ACK / NACK generation unit 63 generates a NACK (retransmission request) when a detection result with an error is obtained (or when packet data cannot be correctly received).
　変調部６４は、ＣＱＩ生成部６２から出力されたＣＱＩ、またはＡＣＫ／ＮＡＣＫ生成部６３から出力されたＡＣＫまたはＮＡＣＫを変調する。 The modulation unit 64 modulates the CQI output from the CQI generation unit 62 or the ACK or NACK output from the ACK / NACK generation unit 63.
　無線送信部６５は、変調部６４からの出力に対して増幅等を行い、無線信号に変換する。 The wireless transmission unit 65 amplifies the output from the modulation unit 64 and converts it to a wireless signal.
　送信アンテナ６６は、無線送信部６５から出力された無線信号を基地局１０に送信する。端末５０は、ＡＣＫまたはＮＡＣＫ、及びＣＱＩ等を基地局１０に送信する。 The transmission antenna 66 transmits the radio signal output from the radio transmission unit 65 to the base station 10. The terminal 50 transmits ACK or NACK, CQI, and the like to the base station 10.
　次に動作について説明する。図４は本第２の実施例における動作例を示すフローチャートである。同図に示すフローチャートは、主に基地局１０のＨＡＲＱ制御部２６とＡＭＣ制御部２７で行われる。 Next, the operation will be described. FIG. 4 is a flowchart showing an operation example in the second embodiment. The flowchart shown in the figure is mainly performed by the HARQ control unit 26 and the AMC control unit 27 of the base station 10.
　処理が開始されると（Ｓ１０）、基地局１０は端末５０から送信されたＣＱＩを受信する（Ｓ１１）。端末５０から受信したＣＱＩは、受信アンテナ２１等を介して、ＡＭＣ制御部２７に出力される。 When the process is started (S10), the base station 10 receives the CQI transmitted from the terminal 50 (S11). The CQI received from the terminal 50 is output to the AMC control unit 27 via the reception antenna 21 and the like.
　次いで、ＡＭＣ制御部２７は再送パケットの有無を確認する（Ｓ１２）。例えば、ＡＭＣ制御部２７はバッファ１３にパケットデータが記憶されていれば再送パケット有り、そうでなければ再送パケット無しを確認する。 Next, the AMC control unit 27 confirms the presence / absence of a retransmission packet (S12). For example, the AMC control unit 27 confirms that there is a retransmission packet if packet data is stored in the buffer 13, and that there is no retransmission packet otherwise.
　ＡＭＣ制御部２７は、再送パケットが無ければ（Ｓ１２で「無」）、新規パケットの有無を確認する（Ｓ１３）。例えば、ＡＭＣ制御部２７は、新規パケットの有無を上位レイヤまたは上位装置からの通知により確認する。 If there is no retransmission packet (“No” in S12), the AMC control unit 27 confirms the presence or absence of a new packet (S13). For example, the AMC control unit 27 confirms the presence / absence of a new packet by notification from an upper layer or an upper device.
　ＡＭＣ制御部２７は、新規パケットが有れば（Ｓ１３で「有」）、ＣＱＩに基づいてパケットサイズ、変調方式、符号化率を決定する（Ｓ１４，Ｓ１５）。 If there is a new packet (“Yes” in S13), the AMC control unit 27 determines the packet size, modulation scheme, and coding rate based on the CQI (S14, S15).
　次いで、基地局１０は決定したパケットサイズ等に基づいて新規パケットを生成し、送信する（Ｓ１６）。 Next, the base station 10 generates and transmits a new packet based on the determined packet size and the like (S16).
　一方、ＡＭＣ制御部２７は、新規パケットがなければ（Ｓ１３で「無」）、送信すべきパケットがないため、Ｓ１１の処理を行う。 On the other hand, if there is no new packet (“No” in S13), the AMC control unit 27 performs S11 because there is no packet to be transmitted.
　また、ＡＭＣ制御部２７は、再送パケットが有る場合（Ｓ１２で「有」）、Ｓ１５の処理に移行して再送パケットに対する変調、符号化率を決定し、再送パケットが送信される（Ｓ１６）。 In addition, when there is a retransmission packet (“Yes” in S12), the AMC control unit 27 proceeds to the processing of S15, determines the modulation and coding rate for the retransmission packet, and transmits the retransmission packet (S16).
　次いで、基地局１０は端末５０から新規パケットまたは再送パケットに対するＡＣＫまたはＮＡＣＫを受信する（Ｓ１７）。端末５０から送信されたＡＣＫまたはＮＡＣＫは、受信アンテナ２１等を介して、ＡＣＫ／ＮＡＣＫ判定部２４においてＡＣＫまたはＮＡＣＫが判定される。判定結果はＨＡＲＱ制御部２６に出力される。 Next, the base station 10 receives ACK or NACK for the new packet or retransmission packet from the terminal 50 (S17). The ACK / NACK determination unit 24 determines ACK or NACK of the ACK or NACK transmitted from the terminal 50 via the reception antenna 21 or the like. The determination result is output to the HARQ control unit 26.
　次いで、ＨＡＲＱ制御部２６は、ＡＣＫを受信したとき（Ｓ１８で「Ａｃｋ」）、端末５０は新規パケットまたは再送パケットを誤りなく受信したため、再送パケットを送信することなく、一連の処理を終了し（Ｓ２１）、Ｓ１１の処理に移行する。この場合、例えばＨＡＲＱ制御部２６は、再送しないことをＡＭＣ制御部２７に通知し、ＡＭＣ制御部２７はバッファ１３に記憶された新規パケットまたは再送パケットのデータをクリアする。 Next, when the HARQ control unit 26 receives an ACK (“Ack” in S18), the terminal 50 has received a new packet or a retransmission packet without error, and thus ends a series of processes without transmitting a retransmission packet ( The process proceeds to S21) and S11. In this case, for example, the HARQ control unit 26 notifies the AMC control unit 27 that retransmission is not performed, and the AMC control unit 27 clears the data of the new packet or the retransmission packet stored in the buffer 13.
　一方、ＨＡＲＱ制御部２６は、ＮＡＣＫを受信したとき（Ｓ１８で「Ｎａｃｋ」）、再送パケットの再送回数が閾値（規定回数）を超えたか否かを判断する（Ｓ１９）。例えば、ＨＡＲＱ制御部２６はこれまで再送した再送回数と閾値とを記憶し、ＮＡＣＫ受信による再送回数と閾値を比較することで判断できる。ＨＡＲＱ制御部２６は、再送回数に代えて、新規パケットの送信後の経過時間が閾値（規定時間）を超えたか否かにより判断してもよい。 On the other hand, when receiving the NACK (“Nack” in S18), the HARQ control unit 26 determines whether or not the number of retransmissions of the retransmission packet has exceeded a threshold (specified number) (S19). For example, the HARQ control unit 26 stores the number of retransmissions that have been retransmitted so far and a threshold value, and can determine by comparing the number of retransmissions by NACK reception and the threshold value. The HARQ control unit 26 may determine whether or not the elapsed time after transmission of a new packet exceeds a threshold value (specified time) instead of the number of retransmissions.
　ＨＡＲＱ制御部２６は、再送回数が閾値を超えた場合（Ｓ１９でＹｅｓ）、再送パケットを再送することなく、一連の処理を終了する。処理はＳ１１に移行する。 When the number of retransmissions exceeds the threshold (Yes in S19), the HARQ control unit 26 ends the series of processes without retransmitting the retransmission packet. The process proceeds to S11.
　一方、ＨＡＲＱ制御部２６は、再送回数が閾値を超えない場合（Ｓ１９でＮｏ）、ＣＱＩ判定部２５から出力されたＣＱＩに基づいて、品質は満足しているか否かを判断する（Ｓ２０）。 On the other hand, if the number of retransmissions does not exceed the threshold (No in S19), the HARQ control unit 26 determines whether the quality is satisfied based on the CQI output from the CQI determination unit 25 (S20).
　パケットを送信したときの通信品質がそれ以前の通信品質よりも良い場合に、基地局１０が端末５０からＮＡＣＫを受信した場合、端末５０側で何らかの問題が生じている可能性がある。 When the communication quality when the packet is transmitted is better than the previous communication quality, if the base station 10 receives a NACK from the terminal 50, there may be some problem on the terminal 50 side.
　一方、端末５０の第２の誤り検出部６１は、これまで受信したパケットデータと再送パケットのデータとを合成したものに対して誤り検出を行う。端末５０は、例えば他端末あての新規パケットを誤って受信した場合、新規パケットと再送パケットとを何回合成しても、第２の誤り検出部６１において誤りが検出される。この場合、端末５０は繰り返しＮＡＣＫを送信する。 On the other hand, the second error detection unit 61 of the terminal 50 performs error detection on a combination of the packet data received so far and the data of the retransmission packet. For example, if the terminal 50 receives a new packet addressed to another terminal by mistake, the second error detection unit 61 detects an error no matter how many times the new packet and the retransmission packet are combined. In this case, the terminal 50 repeatedly transmits NACK.
　本第２の実施例において、基地局１０は、パケットを送信したときの通信品質がそれ以前の通信品質よりもよい場合に、過剰な通信品質に基づいてパケットが送信されているとして、端末５０からＮＡＣＫを受信し規定回数に達していなくても、再送を行わないようにする。これにより、再送パケットの送信が停止され、本無線通信システム１は、その後の処理の遅延を防止できる。また、本無線通信システム１は無線リソースを有効活用できる。例えば、ＨＡＲＱ制御部２６が品質判定（Ｓ２０）を行う。 In the second embodiment, the base station 10 determines that the packet is transmitted based on the excessive communication quality when the communication quality when the packet is transmitted is better than the previous communication quality. Even if the NACK is received and the specified number of times has not been reached, retransmission is not performed. Thereby, the transmission of the retransmission packet is stopped, and the wireless communication system 1 can prevent a delay in subsequent processing. In addition, the wireless communication system 1 can effectively use wireless resources. For example, the HARQ control unit 26 performs quality determination (S20).
　ＨＡＲＱ制御部２６は、品質判定（Ｓ２０）の処理を、例えば、「実際にパケットを送信したときの伝搬路の品質」と「想定した伝搬路の品質」とを比較することで行う。ＨＡＲＱ制御部２６は、前者の方が後者よりも高い数値のとき、品質は満足できるものとして（Ｓ２０でＹｅｓ）、規定回数に達しなくても再送パケットの送信を停止する（Ｓ２１）。一方、ＨＡＲＱ制御部２６は、後者の方が前者よりも高い数値のとき、品質は満足できないとして（Ｓ２０でＮｏ）、再送パケットを送信する（Ｓ２２）。そして、処理はＳ１１に移行し、基地局１０は上述の処理を繰り返す。 The HARQ control unit 26 performs the quality determination (S20) processing by comparing, for example, “the quality of the propagation path when the packet is actually transmitted” and “the quality of the assumed propagation path”. When the former is a numerical value higher than the latter, the HARQ control unit 26 determines that the quality is satisfactory (Yes in S20), and stops transmission of the retransmission packet even if the specified number of times has not been reached (S21). On the other hand, when the latter is a higher numerical value than the former, the HARQ control unit 26 determines that the quality cannot be satisfied (No in S20), and transmits a retransmission packet (S22). And a process transfers to S11 and the base station 10 repeats the above-mentioned process.
　図５（Ａ）及び同図（Ｂ）はパケットの送受信例を示す図である。これらの図は２回目の再送パケットで再送が停止される例を示す。 FIG. 5 (A) and FIG. 5 (B) are diagrams showing examples of packet transmission / reception. These figures show an example in which retransmission is stopped by the second retransmission packet.
　基地局１０はパイロット信号を送信する。端末５０のＣＱＩ生成部６２はパイロット信号に基づいてＣＱＩを生成する。生成されたＣＱＩ（１回目のＣＱＩ）は変調部６４等を介して端末５０に送信される。 The base station 10 transmits a pilot signal. The CQI generator 62 of the terminal 50 generates a CQI based on the pilot signal. The generated CQI (first CQI) is transmitted to terminal 50 via modulator 64 and the like.
　一方、基地局１０は１回目のＣＱＩに基づいて新規パケットを送信する（図４のＳ１１～Ｓ１６）。基地局１０のＡＭＣ制御部２７は新規パケットのサイズ等を決定し、誤り検出符号化部１１等で誤り検出符号化等の処理が行われて、新規パケットが送信される。 Meanwhile, the base station 10 transmits a new packet based on the first CQI (S11 to S16 in FIG. 4). The AMC control unit 27 of the base station 10 determines the size and the like of the new packet, the error detection coding unit 11 and the like perform processing such as error detection coding, and the new packet is transmitted.
　端末５０の誤り検出部６１は新規パケットの誤りを検出し、端末５０はＮＡＣＫを送信する。また、端末５０のＣＱＩ生成部６２は、パイロット信号に基づいて新たにＣＱＩ（２回目のＣＱＩ）を生成し、端末５０は当該ＣＱＩを送信する。 The error detector 61 of the terminal 50 detects an error in the new packet, and the terminal 50 transmits a NACK. In addition, the CQI generation unit 62 of the terminal 50 newly generates a CQI (second CQI) based on the pilot signal, and the terminal 50 transmits the CQI.
　そして、基地局１０は、ＮＡＣＫを受信し（Ｓ１８で「Ｎａｃｋ」）、規定回数に達していないため（Ｓ１９でＮｏ）、品質は満足するか否かを判断する（Ｓ２０）。例えば、ＨＡＲＱ制御部２６は、１回目のＣＱＩを「想定した伝搬路の品質」、２回目のＣＱＩを「実際にパケットを送信したときの伝搬路の品質」とし、両者を比較する。この場合、１回目のＣＱＩの方が高いため（Ｓ２０でＮｏ）、ＨＡＲＱ制御部２６は再送パケットの送信を指示する（Ｓ２２）。 The base station 10 receives the NACK (“Nack” in S18) and does not reach the specified number of times (No in S19), and therefore determines whether the quality is satisfied (S20). For example, the HARQ control unit 26 sets the first CQI as “assumed propagation path quality” and the second CQI as “quality of propagation path when packets are actually transmitted”, and compares the two. In this case, since the first CQI is higher (No in S20), the HARQ control unit 26 instructs transmission of a retransmission packet (S22).
　その後、再び、端末５０はパイロット信号に基づいてＣＱＩ（３回目のＣＱＩ）を生成して送信し、正しく再送パケットを受信できなかったためＮＡＣＫを送信する。 After that, the terminal 50 again generates and transmits a CQI (third CQI) based on the pilot signal, and transmits a NACK because the retransmission packet cannot be correctly received.
　基地局１０のＨＡＲＱ制御部２６は、品質判定を行う（Ｓ２０）。この例の場合、ＨＡＲＱ制御部２６は、２回目のＣＱＩと３回目のＣＱＩとを合成（または合計）したものを「実際にパケットを送信したときの伝搬路の品質」とし、１回目のＣＱＩを「想定した伝搬路の品質」とし、両者を比較する。 The HARQ control unit 26 of the base station 10 performs quality determination (S20). In this example, the HARQ controller 26 combines (or sums) the second CQI and the third CQI as “the quality of the propagation path when the packet is actually transmitted”, and the first CQI. Is “assumed propagation path quality” and compared.
　この例の場合、ＨＡＲＱ制御部２６は、前者の方が後者よりも高い値のため、品質過剰として、再送を停止する（Ｓ２０でＮｏ，Ｓ２１）。伝搬路の品質が十分で、基地局１０がその品質に基づいて送信パケットを生成し送信しても、例えば端末５０で誤ったパケットの受信によってＮＡＣＫ信号を送信する可能性が高いと考えられるからである。 In the case of this example, the HARQ control unit 26 stops retransmission due to excessive quality because the former is higher in value than the latter (No in S20, S21). Even if the quality of the propagation path is sufficient and the base station 10 generates and transmits a transmission packet based on the quality, it is considered that there is a high possibility that the terminal 50 transmits a NACK signal by receiving an erroneous packet, for example. It is.
　ここで、２回目と３回目のＣＱＩとが合成されるのは、端末５０の第２の誤り検出部６１が、新規パケットと再送パケットとの各データを合成し、合成したデータに基づいて誤り検出をしているためである。 Here, the second and third CQIs are combined because the second error detection unit 61 of the terminal 50 combines the data of the new packet and the retransmission packet, and the error is based on the combined data. This is because of the detection.
　図６（Ａ）及び同図（Ｂ）はパケット送受信の他の例を示す図である。図６（Ａ）及び同図（Ｂ）に示す例は３回目の再送パケットの再送が停止される例である。尚、ＣＱＩ＝ＳＮＲ（Signal
to Noise ratio）［ｄＢ］とし、数値を用いて説明する。 6A and 6B are diagrams showing another example of packet transmission / reception. The example shown in FIGS. 6A and 6B is an example in which the retransmission of the third retransmission packet is stopped. CQI = SNR (Signal
to Noise ratio) [dB] and will be described using numerical values.
　端末５０はパイロット信号に基づいてＣＱＩ＝２０（１回目のＣＱＩ）を送信する。基地局１０は、ＣＱＩ＝２０に基づいて、ＣＱＩ＝２０で端末５０が受信可能な新規パケットを生成し送信する（Ｓ１１～Ｓ１６）。 Terminal 50 transmits CQI = 20 (first CQI) based on the pilot signal. Based on CQI = 20, base station 10 generates and transmits a new packet that can be received by terminal 50 with CQI = 20 (S11 to S16).
　端末５０は、新規パケットを正しく受信できなかったためＮＡＣＫを送信する。また、端末５０はパイロット信号に基づいてＣＱＩ＝１５（２回目のＣＱＩ）を送信する。 The terminal 50 transmits a NACK because it cannot correctly receive a new packet. Further, terminal 50 transmits CQI = 15 (second CQI) based on the pilot signal.
　基地局１０は、規定回数に達していないため（Ｓ１９でＮｏ）、品質が満足できるか否かを判定する（Ｓ２０）。ＨＡＲＱ制御部２６は、１回目のＣＱＩ＝２０を「想定した伝搬路の品質」、２回目のＣＱＩ＝１２を「実際にパケットを送信したときの伝搬路の品質」とし、両者を比較する。この場合、前者の方が高い数値のため、ＨＡＲＱ制御部２６は再送パケット（１回目の再送パケット）を送信する（Ｓ２０でＮｏ，Ｓ２２）。 Since the base station 10 has not reached the specified number of times (No in S19), the base station 10 determines whether the quality is satisfactory (S20). The HARQ control unit 26 sets the first CQI = 20 as “assumed propagation path quality” and the second CQI = 12 as “quality of propagation path when packets are actually transmitted”, and compares the two. In this case, since the former is a higher numerical value, the HARQ control unit 26 transmits a retransmission packet (first retransmission packet) (No in S20, S22).
　図６（Ａ）等の例において、再送パケットは、例えば新規パケットと同じ条件（ＣＱＩ＝２０に対応する変調方式及び符号化率等）で送信される。再送パケットは、新規パケットと異なる条件で送信されてもよい。再送パケットの送信はＡＭＣ制御部２７等により行われる（Ｓ１５，Ｓ１６）。 In the example of FIG. 6A and the like, the retransmission packet is transmitted, for example, under the same conditions as the new packet (modulation scheme and coding rate corresponding to CQI = 20). The retransmission packet may be transmitted under different conditions from the new packet. The retransmission packet is transmitted by the AMC control unit 27 or the like (S15, S16).
　端末５０は、再送パケットを受信したものの、正しく受信できなかったため、ＮＡＣＫを送信する。また、端末５０は、パイロット信号に基づいてＣＱＩ＝１２（３回目のＣＱＩ）を送信する。 Since the terminal 50 has received the retransmission packet but has not received it correctly, it transmits a NACK. Also, terminal 50 transmits CQI = 12 (third CQI) based on the pilot signal.
　基地局１０は、ＮＡＣＫを受信し、規定回数に達しないため（Ｓ１８でＮａｃｋ、Ｓ１９でＮｏ）、品質を判定する（Ｓ２０）。ＨＡＲＱ制御部２６は、２回目のＣＱＩ（＝１５）と３回目のＣＱＩ（＝１２）とを合成したものを「実際に送信した伝搬路の品質」とする。合成値Ｘは、例えば、
Ｘ［ｄＢ］＝１０×ｌｏｇ（Ｙ），Ｙ＝１０^（ｘ［ｄＢ］／１０）　　・・・（１）
により求められる。実際に計算すると、合成値Ｘは、１０×ｌｏｇ（１０^（１５／１０）＋１０^（１２／１０））＝１６．７［ｄＢ］となる。 Since the base station 10 receives the NACK and does not reach the specified number of times (Nack in S18, No in S19), the base station 10 determines the quality (S20). The HARQ controller 26 combines the second CQI (= 15) and the third CQI (= 12) as “the quality of the actually transmitted channel”. The composite value X is, for example,
X [dB] = 10 × log (Y), Y = 10 ^ (x [dB] / 10) (1)
It is calculated by. When actually calculated, the composite value X is 10 × log (10 ^ (15/10) + 10 ^ (12/10)) = 16.7 [dB].
　一方、基地局１０はＣＱＩ＝２０を条件として、新規パケットと１回目の再送パケットとを送信しており、１回目の再送パケットは新規パケットと比較して３［ｄＢ］強く送信したものと等価である。よって、ＨＡＲＱ制御部２６は、ＣＱＩ＝１７を「想定した伝搬路の品質」とし、「実際にパケットを送信したときの伝搬路の品質」であるＣＱＩ＝１６．７と比較する。この場合、前者の方が後者よりも高い数値のため、ＨＡＲＱ制御部２６は再送を実行する（Ｓ２０でＮｏ，Ｓ２２）。ＡＭＣ制御部２７等は、新規パケットと同様にＣＱＩ＝２０を条件として２回目の再送パケットを生成し送信する。この場合、２回目の再送パケットは新規パケットより４．７［ｄＢ］強いパケットを送信したものと等価である。基地局１０は、ＣＱＩ＝１５．３［ｄＢ］でも端末５０が受信できることを期待して２回目の再送パケットを送信する。 On the other hand, the base station 10 transmits a new packet and a first retransmission packet on condition that CQI = 20, and the first retransmission packet is equivalent to a packet transmitted 3 [dB] stronger than the new packet. It is. Therefore, the HARQ control unit 26 sets CQI = 17 as “assumed propagation path quality” and compares it with CQI = 16.7, which is “propagation path quality when packets are actually transmitted”. In this case, since the former is a higher numerical value than the latter, the HARQ control unit 26 performs retransmission (No in S20, S22). The AMC control unit 27 and the like generate and transmit a second retransmission packet on the condition of CQI = 20 as in the new packet. In this case, the second retransmission packet is equivalent to a packet transmitted 4.7 [dB] stronger than the new packet. The base station 10 transmits the second retransmission packet in expectation that the terminal 50 can receive even with CQI = 15.3 [dB].
　端末５０は、２回目の再送パケットを正しく受信できなかったため、ＮＡＣＫを送信する。また、端末５０はパイロット信号に基づいてＣＱＩ＝１３（３回目のＣＱＩ）を送信する。 Since the terminal 50 has not received the second retransmission packet correctly, it transmits a NACK. Also, terminal 50 transmits CQI = 13 (third CQI) based on the pilot signal.
　基地局１０は、ＮＡＣＫを受信し（Ｓ１８で「Ｎａｃｋ」）、規定回数に達していないため（Ｓ１９でＮｏ）、品質判定を行う（Ｓ２０）。 The base station 10 receives the NACK (“Nack” in S18) and does not reach the specified number of times (No in S19), and thus performs quality determination (S20).
　ＨＡＲＱ制御部２６は、ＣＱＩ＝２０により３回パケットを送信しているため、「想定した伝搬路の品質」をＣＱＩ＝１５．３とする。また、ＨＡＲＱ制御部２６は、「実際にパケットを送信したときの伝搬路の品質」を式（１）に基づいて計算する。計算すると、Ｘ＝１０×（ｌｏｇ（１０^（１５／１０）＋１０^（１２／１０）＋１０^（１３／１０））＝１８．２となる。この場合、「実際にパケットを送信したときの伝搬路の品質」の方が、「想定した伝搬路の品質」よりも高い数値のため、ＨＡＲＱ制御部２６は、品質が過剰として再送を停止する（Ｓ２０でＹｅｓ，Ｓ２１）。 Since the HARQ control unit 26 transmits the packet three times with CQI = 20, “assumed propagation path quality” is set to CQI = 15.3. Also, the HARQ control unit 26 calculates “the quality of the propagation path when the packet is actually transmitted” based on the equation (1). When calculated, X = 10 × (log (10 ^ (15/10) + 10 ^ (12/10) + 10 ^ (13/10)) = 18.2. In this case, “when a packet is actually transmitted” Since “the quality of the propagation path” is higher than the “assumed propagation path quality”, the HARQ control unit 26 stops the retransmission because the quality is excessive (Yes in S20, S21).
　図６（Ａ）及び同図（Ｂ）に示す例では、２回目の再送パケットを基地局１０が送信したときの通信品質は、１回目の再送パケット等を基地局１０が送信したときの通信品質よりも良くなっている例である。この場合、基地局１０は、当該通信品質に基づいて再送パケットを送信しており、端末１０側で誤ったパケットを受信していると考え、ＮＡＣＫを受信しても再送パケットを送信しないようにしている。なお、図６（Ａ）等の例で、ＣＱＩ＝ＳＩＲとしたのは一例であり、ＳＩＮＲ（Signal
to Interference and Noise Ratio）、ＣＩＮＲ（Carrier to
Interference plus Noise Ratio）等でもよい。 In the example shown in FIGS. 6A and 6B, the communication quality when the base station 10 transmits the second retransmission packet is the communication quality when the base station 10 transmits the first retransmission packet or the like. This is an example that is better than quality. In this case, the base station 10 transmits a retransmission packet based on the communication quality, considers that the terminal 10 has received an erroneous packet, and does not transmit a retransmission packet even if a NACK is received. ing. In the example of FIG. 6A and the like, CQI = SIR is an example, and SINR (Signal
to Interference and Noise Ratio), CINR (Carrier to
Interference plus Noise Ratio) may be used.
　次に他の例について説明する。 Next, another example will be described.
　基地局１０は、例えば再送を停止した場合（Ｓ２０でＹｅｓ，Ｓ２１）、その旨を上位レイヤ（または上位装置）に通知するようにしてもよい。上位レイヤ等も再送パケットのパケットデータを保持しており、当該通知を行うことで、例えば保持したパケットデータをクリア等することができ、処理の効率化を図ることができる。 For example, when the retransmission is stopped (Yes in S20, S21), the base station 10 may notify the upper layer (or upper device) to that effect. The upper layer or the like also holds the packet data of the retransmitted packet, and by performing the notification, for example, the held packet data can be cleared and the processing efficiency can be improved.
　図７は処理の例を示すフローチャート、図８は基地局１０の構成例をそれぞれ示す図である。なお、図８では、上位レイヤの例としてＡＲＱ再送制御部２９を示す。ＡＲＱ再送制御部２９は、３ＧＰＰのＲＬＣ（Radio
Link Control：無線リンク制御）に相当し、例えば、保持したパケットの再送制御以外にも、パケットデータ等のシーケンス番号の管理等を行う。 FIG. 7 is a flowchart illustrating an example of processing, and FIG. 8 is a diagram illustrating a configuration example of the base station 10. In FIG. 8, the ARQ retransmission control unit 29 is shown as an example of the upper layer. The ARQ retransmission control unit 29 is a 3GPP RLC (Radio).
For example, in addition to retransmission control of held packets, the management of sequence numbers of packet data and the like is performed.
　図７に示すように、ＨＡＲＱ制御部２６は、再送回数が規定回数に達していなくても（Ｓ１９でＮｏ）、品質が満足できる場合（Ｓ２０でＹｅｓ）、再送を停止した旨をＡＲＱ再送制御部２９に通知する（Ｓ３０）。そして、ＨＡＲＱ制御部２６は、再送パケットの送信を停止する（Ｓ２１）。 As shown in FIG. 7, even if the number of retransmissions has not reached the specified number (No in S19), the HARQ control unit 26 indicates that the retransmission has been stopped if the quality is satisfactory (Yes in S20). This is notified to the unit 29 (S30). Then, the HARQ control unit 26 stops transmission of the retransmission packet (S21).
　他の例として、基地局１０は、再送パケットを新規パケットとして端末５０に送信することもできる。端末５０は、バッファ５９に他の端末あてのパケットデータを誤って記憶している場合に、再送パケットを受信しても、何度もＮＡＣＫを送信する。しかし、端末５０は、新規パケットを受信したとき、第２の誤り検出部６１によりバッファ５９がクリアされることで、誤りのないパケットデータを記憶できる。 As another example, the base station 10 can also transmit a retransmission packet to the terminal 50 as a new packet. If the terminal 50 erroneously stores the packet data addressed to another terminal in the buffer 59, the terminal 50 transmits NACK many times even if the retransmission packet is received. However, when the terminal 50 receives a new packet, the second error detection unit 61 clears the buffer 59, thereby storing error-free packet data.
　図９はかかる例の動作例を示すフローチャートである。例えば、ＡＭＣ制御部２７はＣＱＩを受信（Ｓ１１）後、再送パケットを新規パケットとして送信するときのパケットデータが存在するか否かを確認する（Ｓ４０）。例えば、ＡＭＣ制御部２７はバッファ１３に再送パケットのデータが記憶されていれば、新規パケットが存在する（Ｓ４０で「有」）として、Ｓ１５の処理に移行する。あるいは、ＡＭＣ制御部２７は上位レイヤからの通知により、新規パケットの有無を確認するようにしてもよい。 FIG. 9 is a flowchart showing an operation example of this example. For example, after receiving the CQI (S11), the AMC control unit 27 checks whether or not there is packet data for transmitting a retransmission packet as a new packet (S40). For example, if the retransmission packet data is stored in the buffer 13, the AMC control unit 27 determines that a new packet exists (“Yes” in S 40), and proceeds to S 15. Alternatively, the AMC control unit 27 may confirm the presence / absence of a new packet by a notification from an upper layer.
　一方、ＡＭＣ制御部２７は、新規パケットが存在しなければ（Ｓ４０で「無」）、Ｓ１２の処理に移行する。そして、ＨＡＲＱ制御部２６は、品質が満足できる場合（Ｓ２０でＹｅｓ）、再送パケットの送信を停止し、再送パケットを新規パケットして送信する（Ｓ４１）。 On the other hand, if there is no new packet (“No” in S40), the AMC control unit 27 proceeds to the process of S12. If the quality is satisfactory (Yes in S20), the HARQ control unit 26 stops transmitting the retransmission packet, and transmits the retransmission packet as a new packet (S41).
　また、他の例として、端末５０は、ＣＱＩを求める際に、パケットデータを復調する際に使用したパイロット信号に対して品質を測定し、ＣＱＩとして基地局１０に送信するようにしてもよい。図１０（Ａ）及び同図（Ｂ）はパケットの送受信例を示す図である。 As another example, when obtaining the CQI, the terminal 50 may measure the quality of the pilot signal used when demodulating the packet data, and transmit it to the base station 10 as the CQI. FIG. 10A and FIG. 10B are diagrams illustrating an example of packet transmission / reception.
　例えば、３ＧＰＰ‐ＬＴＥ（3rd
Generation Partnership Project- Long Term Evolution）システムでは周波数帯域が他の無線通信システムと比較して広く、パイロット信号の送信帯域が複数の周波数領域（図１０（Ａ）の例は５つ）に分割される。この場合、端末５０は、各領域それぞれに対して伝搬路の品質を測定し、それぞれに対応するＣＱＩを生成して、基地局１０に送信する。基地局１０は、各領域の中から最も品質のよいＣＱＩに対応する周波数領域を用いて新規パケットを送信する。端末５０は、新規パケットを受信して、ＣＱＩを測定することになるが、この場合、新規パケットの送信に用いた周波数帯域（図１０（Ａ）中、２番目の領域）のＣＱＩを測定するようにする。これにより、端末５０は一部の周波数帯域に対して品質を測定し、その品質情報をＣＱＩとして送信すればよいため、全帯域について品質を測定する場合と比較して処理の軽減、電力増加防止等を図ることができる。 For example, 3GPP-LTE (3rd
In the Generation Partnership Project-Long Term Evolution) system, the frequency band is wider than other wireless communication systems, and the pilot signal transmission band is divided into a plurality of frequency regions (in the example of FIG. 10A, five). . In this case, the terminal 50 measures the quality of the propagation path for each region, generates a CQI corresponding to each, and transmits the CQI to the base station 10. The base station 10 transmits a new packet using the frequency domain corresponding to the CQI with the highest quality among the areas. The terminal 50 receives the new packet and measures the CQI. In this case, the terminal 50 measures the CQI of the frequency band (second area in FIG. 10A) used for transmitting the new packet. Like that. As a result, the terminal 50 only needs to measure the quality for a part of the frequency bands and transmit the quality information as CQI. Therefore, compared with the case where the quality is measured for all bands, the processing is reduced and the increase in power is prevented. Etc. can be achieved.
　例えば、基地局１０のＡＭＣ制御部２７はＣＱＩ判定部２５からの判定結果に基づいて、どの周波数グループのＣＱＩが最もよいかを判定し、どのグループを用いたかを示す情報を制御情報に含めることで当該情報が端末５０に送信される。そして、端末５０の制御情報解析部５６は、どのグループを利用したかの情報を、復調部５７を介してＣＱＩ生成部６２に出力し、ＣＱＩ生成部６２は当該情報を利用してＣＱＩを測定する。 For example, the AMC control unit 27 of the base station 10 determines which frequency group has the best CQI based on the determination result from the CQI determination unit 25 and includes information indicating which group is used in the control information. Then, the information is transmitted to the terminal 50. Then, the control information analysis unit 56 of the terminal 50 outputs information indicating which group is used to the CQI generation unit 62 via the demodulation unit 57, and the CQI generation unit 62 measures the CQI using the information. To do.
　＜第３の実施例＞
　次に第３の実施例について説明する。第３の実施例は、パケットデータが端末５０から基地局１０方向に向けて送信される上り方向の例である。送信局装置が端末５０、受信局装置が基地局１０である。図１１は端末５０、図１２は基地局１０の構成例を示す図である。 <Third embodiment>
Next, a third embodiment will be described. The third embodiment is an example of the uplink direction in which packet data is transmitted from the terminal 50 toward the base station 10. The transmitting station device is the terminal 50 and the receiving station device is the base station 10. FIG. 11 is a diagram illustrating a configuration example of the terminal 50 and FIG. 12 is a diagram illustrating a configuration example of the base station 10.
　端末５０は、誤り検出符号化部７０と、誤り訂正符号化部７１と、バッファ７２と、第３の変調部７３と、パイロット信号発生部７４と、第４の変調部７５と、無線送信部７６と、送信アンテナ７７と、受信アンテナ８０と、無線受信部８１と、復調部８２と、ＡＣＫ／ＮＡＣＫ判定部８３と、ＨＡＲＱ制御部８４と、ｇｒａｎｔ判定部８５と、ＡＭＣ制御部８６とを備える。 The terminal 50 includes an error detection encoding unit 70, an error correction encoding unit 71, a buffer 72, a third modulation unit 73, a pilot signal generation unit 74, a fourth modulation unit 75, and a radio transmission unit. 76, transmission antenna 77, reception antenna 80, radio reception unit 81, demodulation unit 82, ACK / NACK determination unit 83, HARQ control unit 84, grant determination unit 85, and AMC control unit 86. Prepare.
　例えば、第１の実施例における送信部１１０は、誤り検出符号化部７０から送信アンテナ７７に対応し、受信部１２０は、受信アンテナ８０からＡＭＣ制御部８６に対応する。 For example, the transmission unit 110 in the first embodiment corresponds to the transmission antenna 77 from the error detection encoding unit 70, and the reception unit 120 corresponds to the AMC control unit 86 from the reception antenna 80.
　誤り検出符号化部７０は、基地局１０に送信するパケットデータの誤りを検出し、符号化を行う。誤り検出符号化部７０は、パケットデータが新規の場合、当該パケットデータに対してＡＭＣ制御部８６で決定したパケットサイズとなるように出力する。 The error detection encoding unit 70 detects an error in the packet data transmitted to the base station 10 and performs encoding. When the packet data is new, the error detection encoding unit 70 outputs the packet data so that the packet size is determined by the AMC control unit 86.
　誤り訂正符号化部７１は、誤り検出が行われたパケットデータに対して、誤りがあれば誤り訂正を行って符号化を行う。ＡＭＣ制御部８６により決定された符号化率で符号化が行われる。 The error correction coding unit 71 performs coding by performing error correction on the packet data subjected to error detection if there is an error. Encoding is performed at the encoding rate determined by the AMC control unit 86.
　バッファ７２は、誤り訂正がなされたパケットデータを記憶する。記憶されたパケットデータは、ＡＭＣ制御部８６で決定したビットパターンに従って、バッファ７２から読みだされる。 Buffer 72 stores packet data that has been subjected to error correction. The stored packet data is read from the buffer 72 according to the bit pattern determined by the AMC control unit 86.
　第３の変調部７３は、バッファ７２から読み出されたパケットデータを変調する。第３の変調部７３は、ＡＭＣ制御部８６で決定した変調方式に基づいてパケットデータを変調する。 The third modulator 73 modulates the packet data read from the buffer 72. The third modulator 73 modulates the packet data based on the modulation scheme determined by the AMC controller 86.
　パイロット信号発生部７４は、端末５０から送信するパイロット信号を生成する。 The pilot signal generator 74 generates a pilot signal to be transmitted from the terminal 50.
　第４の変調部７５は、パイロット信号を変調する。 The fourth modulator 75 modulates the pilot signal.
　無線送信部７６は、第３の変調部７３からのパケットデータと、第４の変調部７５からのパイロット信号とを、ＡＭＣ制御部８６で決定した送信電力に従って増幅等を行い、無線信号に変換する。 The wireless transmission unit 76 amplifies the packet data from the third modulation unit 73 and the pilot signal from the fourth modulation unit 75 according to the transmission power determined by the AMC control unit 86, and converts the data into a radio signal To do.
　送信アンテナ７７は、無線信号を基地局１０に送信する。 The transmission antenna 77 transmits a radio signal to the base station 10.
　受信アンテナ８０は、基地局１０から送信された無線信号を受信する。無線信号には、ＡＣＫまたはＮＡＣＫと、ｇｒａｎｔとを含む。ｇｒａｎｔは、上り方向のパケットデータに対する、パケットサイズ、変調方式、符号化率、送信ビットパターン等の各情報を含む。 The receiving antenna 80 receives a radio signal transmitted from the base station 10. The radio signal includes ACK or NACK and grant. The grant includes various pieces of information such as a packet size, a modulation scheme, a coding rate, a transmission bit pattern, and the like with respect to uplink packet data.
　無線受信部８１は、基地局１０において無線信号変換前の信号に変換する。 The radio reception unit 81 converts the signal before the radio signal conversion in the base station 10.
　復調部８２は、無線受信部８１の出力を復調し、復調されたＡＣＫまたはＮＡＣＫをＡＣＫ／ＮＡＣＫ判定部８３、復調されたｇｒａｎｔをｇｒａｎｔ判定部８５に出力する。 The demodulator 82 demodulates the output of the radio receiver 81, and outputs the demodulated ACK or NACK to the ACK / NACK determination unit 83 and the demodulated grant to the grant determination unit 85.
　ＡＣＫ／ＮＡＣＫ判定部８３は、復調部８２から出力されたものがＡＣＫか、ＮＡＣＫかを判定し、判定結果をＨＡＲＱ制御部８４に出力する。 The ACK / NACK determination unit 83 determines whether the output from the demodulation unit 82 is ACK or NACK, and outputs the determination result to the HARQ control unit 84.
　ＨＡＲＱ制御部８４は、ＡＣＫ／ＮＡＣＫ判定部８３からＡＣＫを入力したときは、新規パケットの送信をＡＭＣ制御部８６に指示し、ＮＡＣＫを入力したときはパケットの再送をＡＭＣ制御部８６に指示する。 The HARQ control unit 84 instructs the AMC control unit 86 to transmit a new packet when an ACK is input from the ACK / NACK determination unit 83, and instructs the AMC control unit 86 to retransmit the packet when a NACK is input. .
　ｇｒａｎｔ判定部８５は、ｇｒａｎｔに含まれるパケットサイズ等の情報を取り出し、ＡＭＣ制御部８６に出力する。 The grant determination unit 85 extracts information such as a packet size included in the grant and outputs the information to the AMC control unit 86.
　ＡＭＣ制御部８６は、ＨＡＲＱ制御部８４から新規パケットの送信が指示されたとき、ｇｒａｎｔ判定部８５からのパケットサイズを誤り検出符号化部７０に出力し、符号化率、送信ビットパターン、変調方式をそれぞれ誤り訂正符号化部７１、バッファ７２、第３の変調部７３に出力する。また、ＡＭＣ制御部８６は、ＨＡＲＱ制御部８４から再送パケットの送信が指示されたとき、ｇｒａｎｔ判定部８５からの符号化率等を誤り訂正符号化部７１等に出力する。バッファ７２は、例えばＡＭＣ制御部８６からの指示があるまで、再送パケットのデータを送信するためにパケットデータを記憶する。 The AMC control unit 86 outputs the packet size from the grant determination unit 85 to the error detection encoding unit 70 when the transmission of a new packet is instructed from the HARQ control unit 84, and the coding rate, transmission bit pattern, modulation method Are output to the error correction encoding unit 71, the buffer 72, and the third modulation unit 73, respectively. In addition, when the HARQ control unit 84 is instructed to transmit a retransmission packet, the AMC control unit 86 outputs the coding rate from the grant determination unit 85 to the error correction coding unit 71 and the like. The buffer 72 stores packet data for transmitting retransmission packet data until an instruction is given from the AMC control unit 86, for example.
　基地局１０は、受信アンテナ３２と、無線受信部３３と、復調部３４と、合成部３５と、バッファ３６と、誤り訂正復号化部３７と、誤り検出部３８と、品質測定部３９と、ｇｒａｎｔ生成部４０と、ＡＣＫ／ＮＡＣＫ生成部４１と、変調部４２と、無線送信部４３と、送信アンテナ４４とを備える。 The base station 10 includes a reception antenna 32, a radio reception unit 33, a demodulation unit 34, a synthesis unit 35, a buffer 36, an error correction decoding unit 37, an error detection unit 38, a quality measurement unit 39, A grant generation unit 40, an ACK / NACK generation unit 41, a modulation unit 42, a radio transmission unit 43, and a transmission antenna 44 are provided.
　例えば、第１の実施例における受信部２１０は、受信アンテナ３２から誤り検出部３８に対応し、制御部２３０は品質測定部３９、送信部２２０はｇｒａｎｔ生成部４０から送信アンテナ４４にそれぞれ対応する。 For example, the receiving unit 210 in the first embodiment corresponds to the error detecting unit 38 from the receiving antenna 32, the control unit 230 corresponds to the quality measuring unit 39, and the transmitting unit 220 from the grant generating unit 40 to the transmitting antenna 44. .
　受信アンテナ３２は、端末５０から送信された無線信号を受信する。無線信号は、新規パケットまたは再送パケットのパケットデータ、またはパイロット信号等を含む。 The receiving antenna 32 receives a radio signal transmitted from the terminal 50. The radio signal includes packet data of a new packet or retransmission packet, a pilot signal, or the like.
　無線受信部３３は、受信アンテナ３２からの無線信号を、端末５０における無線信号変換前のデータ等に変換する。 The radio reception unit 33 converts the radio signal from the reception antenna 32 into data before radio signal conversion in the terminal 50.
　復調部３４は、無線受信部３３からの出力を復調し、復調後のパケットデータを合成部３５に、復調後のパイロット信号を品質測定部３９にそれぞれ出力する。復調部３４は、品質測定部３９で決定された変調方式に基づいて復調を行う。 The demodulator 34 demodulates the output from the radio receiver 33 and outputs the demodulated packet data to the combiner 35 and the demodulated pilot signal to the quality measurer 39. The demodulator 34 performs demodulation based on the modulation scheme determined by the quality measurement unit 39.
　合成部３５は、復調されたパケットデータが新規パケットのデータの場合、当該データをバッファ３６と誤り訂正復号化部３７に出力する。また、合成部３５は、復調されたパケットデータが再送パケットのデータの場合、当該データとバッファ３６に記憶されたパケットデータとを合成して誤り訂正復号化部３７とバッファ３６に出力する。合成部３５は、品質測定部３９で決定された合成方法等により合成が行われる。 When the demodulated packet data is new packet data, the synthesis unit 35 outputs the data to the buffer 36 and the error correction decoding unit 37. In addition, when the demodulated packet data is retransmission packet data, the combining unit 35 combines the data and the packet data stored in the buffer 36 and outputs the combined data to the error correction decoding unit 37 and the buffer 36. The synthesizer 35 synthesizes by the synthesis method determined by the quality measuring unit 39.
　バッファ３６は、合成部３５から出力されたパケットデータを記憶する。記憶されたパケットデータは、誤り検出部３８により誤りがないことが検出されるとクリアされる。 The buffer 36 stores the packet data output from the combining unit 35. The stored packet data is cleared when the error detecting unit 38 detects that there is no error.
　誤り訂正復号化部３７は、合成部３５から出力されたパケットデータに対して、誤り訂正を行い復号化する。誤り訂正復号化部３７は、品質測定部３９で決定した符号化率に基づいて復号を行う。 The error correction decoding unit 37 performs error correction on the packet data output from the combining unit 35 and decodes the packet data. The error correction decoding unit 37 performs decoding based on the coding rate determined by the quality measurement unit 39.
　誤り検出部３８は、復号後のパケットデータに誤りがあるか否かを検出する。例えば、誤り検出部３８は、誤り訂正復号化部３７で誤り訂正が行われた場合、当該パケットデータに誤りがあると判定し、そうでない場合、誤りがないと判定する。誤り検出後のパケットデータは基地局１０の他の処理部に出力される。 The error detection unit 38 detects whether or not there is an error in the decoded packet data. For example, the error detection unit 38 determines that there is an error in the packet data when the error correction decoding unit 37 performs error correction, and otherwise determines that there is no error. The packet data after error detection is output to another processing unit of the base station 10.
　品質測定部３９は、復調されたパイロット信号に基づいて、上り方向の品質を測定し、ＣＱＩ相当の品質情報を生成する。品質測定部３９は、例えば、この品質情報により上り方向の通信品質を推定する。そして、品質測定部３９は、品質情報に基づいて、端末５０がパケットを送信するときの変調方式、符号化率、パケットサイズ等を決定し、これらの情報を、復調部３４、誤り訂正復号化部３７に出力するとともに、ｇｒａｎｔ生成部４０に出力する。また、品質測定部３９は、品質情報と、誤り検出部３８からの検出結果とに基づいて、第２の実施例と同様に品質判定を行う。品質判定の詳細は後述する。品質測定部３９は、品質測定の結果、再送要求の有無をＡＣＫ／ＮＡＣＫ生成部４１に指示する。品質測定部３９は再送を制御する制御部でもある。 The quality measuring unit 39 measures the quality in the uplink direction based on the demodulated pilot signal and generates quality information corresponding to CQI. For example, the quality measuring unit 39 estimates the uplink communication quality from this quality information. Then, the quality measuring unit 39 determines a modulation scheme, a coding rate, a packet size, and the like when the terminal 50 transmits a packet based on the quality information, and the demodulating unit 34, error correction decoding, and the like. Output to the unit 37 and also to the grant generation unit 40. Further, the quality measuring unit 39 performs the quality determination based on the quality information and the detection result from the error detecting unit 38 as in the second embodiment. Details of the quality determination will be described later. As a result of the quality measurement, the quality measurement unit 39 instructs the ACK / NACK generation unit 41 whether there is a retransmission request. The quality measurement unit 39 is also a control unit that controls retransmission.
　ｇｒａｎｔ生成部４０は、品質測定部３９からの情報に基づいてｇｒａｎｔを生成する。上述したように、ｇｒａｎｔにはパケットサイズ、変調方式、符号化率等が含まれる。 The grant generation unit 40 generates a grant based on information from the quality measurement unit 39. As described above, the grant includes a packet size, a modulation scheme, a coding rate, and the like.
　ＡＣＫ／ＮＡＣＫ生成部４１は、品質測定部３９からの指示に基づいて、ＡＣＫまたはＮＡＣＫを生成する。ＡＣＫ／ＮＡＣＫ生成部４１は、例えば、品質測定部３９から再送要求無しの指示を得た場合、ＡＣＫを生成する。また、ＡＣＫ／ＮＡＣＫ生成部４１は、例えば、品質測定部３９から再送要求有りの指示を得た場合、ＮＡＣＫを生成する。 The ACK / NACK generation unit 41 generates ACK or NACK based on an instruction from the quality measurement unit 39. The ACK / NACK generation unit 41 generates an ACK when an instruction indicating no retransmission request is received from the quality measurement unit 39, for example. Further, the ACK / NACK generation unit 41 generates a NACK, for example, when receiving an instruction for retransmission request from the quality measurement unit 39.
　変調部４２は、ＡＣＫ／ＮＡＣＫ生成部４１からのＡＣＫまたはＮＡＣＫ、あるいはｇｒａｎｔ生成部４０からのｇｒａｎｔを変調する。 The modulation unit 42 modulates ACK or NACK from the ACK / NACK generation unit 41 or grant from the grant generation unit 40.
　無線送信部４３は、変調後のＡＣＫ等を増幅等し、無線信号に変換する。送信アンテナ４４は、無線信号を送信する。 The wireless transmitter 43 amplifies the modulated ACK or the like and converts it to a wireless signal. The transmission antenna 44 transmits a radio signal.
　次に動作について説明する。図１３は本第３の実施例における動作例を示し、主に基地局１０の品質測定部３９等で行われる。 Next, the operation will be described. FIG. 13 shows an operation example in the third embodiment, which is mainly performed by the quality measuring unit 39 of the base station 10 or the like.
　処理が開始されると（Ｓ５０）、基地局１０は端末５０から送信されたパイロット信号を受信し、品質測定部３９はパイロット信号に基づいてＣＱＩ相当の品質情報を演算する（Ｓ５１）。 When the process is started (S50), the base station 10 receives the pilot signal transmitted from the terminal 50, and the quality measuring unit 39 calculates quality information corresponding to CQI based on the pilot signal (S51).
　次いで、品質測定部３９は、誤り検出部３８からの誤り検出結果に基づいて再送要求の有無を判定する（Ｓ５２）。例えば、品質測定部３９は、検出結果が誤りありの場合、再送要求ありと判定し、検出結果が誤りなしの場合、再送要求なしと判定する。 Next, the quality measurement unit 39 determines whether there is a retransmission request based on the error detection result from the error detection unit 38 (S52). For example, the quality measurement unit 39 determines that there is a retransmission request when the detection result has an error, and determines that there is no retransmission request when the detection result has no error.
　品質測定部３９は、再送要求無しの場合（Ｓ５２で「無」）、新規パケットの有無を判定する（Ｓ５３）。例えば、品質測定部３９はバッファ３６に新規パケットのデータが記憶されていれば新規パケット有りと判定し、そうでない場合、新規パケット無しと判定する。新規パケット無しの場合（Ｓ５３で「無」）、処理はＳ５１に移行する。 When there is no retransmission request (“No” in S52), the quality measuring unit 39 determines whether there is a new packet (S53). For example, the quality measuring unit 39 determines that there is a new packet if the data of the new packet is stored in the buffer 36, and determines that there is no new packet otherwise. If there is no new packet (“No” in S53), the process proceeds to S51.
　品質測定部３９は、新規パケット有りの場合（Ｓ５３で「有」）、ＣＱＩ相当の品質情報に基づいてパケットサイズを決定し（Ｓ５４）、変調方式及び符号化率を決定する（Ｓ５５）。 When there is a new packet (“Yes” in S53), the quality measurement unit 39 determines the packet size based on the quality information equivalent to CQI (S54), and determines the modulation method and coding rate (S55).
　一方、品質測定部３９は、再送要求が有る場合（Ｓ５２で「有」）、Ｓ５４の処理を行うことなくＳ５５の処理を行う。 On the other hand, when there is a retransmission request (“Yes” in S52), the quality measuring unit 39 performs the process of S55 without performing the process of S54.
　次いで、ｇｒａｎｔ生成部４０はパケットサイズ、変調方式、及び符号化率等の各情報を含むｇｒａｎｔを生成し、変調部４２等を介して端末５０に送信する（Ｓ５６）。 Next, the grant generation unit 40 generates a grant including each information such as a packet size, a modulation scheme, and a coding rate, and transmits the grant to the terminal 50 via the modulation unit 42 and the like (S56).
　端末５０はｇｒａｎｔに基づいて新規パケットまたは再送パケットを生成し基地局１０に送信する。 The terminal 50 generates a new packet or a retransmission packet based on the grant and transmits it to the base station 10.
　基地局１０は、端末５０から送信された新規パケットまたは再送パケットの各データを受信する（Ｓ５７）。受信したデータは、無線受信部３３等を経由して合成部３５に出力される。合成部３５はバッファ３６にパケットデータが記憶されていれば合成して出力し、記憶されていなければパケットデータを出力する。パケットデータは、誤り訂正復号化部３７を介して誤り検出部３８に出力される。 The base station 10 receives each data of a new packet or a retransmission packet transmitted from the terminal 50 (S57). The received data is output to the synthesis unit 35 via the wireless reception unit 33 and the like. The combining unit 35 combines and outputs the packet data if it is stored in the buffer 36, and outputs the packet data if it is not stored. The packet data is output to the error detection unit 38 via the error correction decoding unit 37.
　次いで、誤り検出部３８は、受信したパケットデータに誤りがあるか否かを検出する（Ｓ５８）。誤り検出部３８は、パケットデータに誤りがないことを検出した場合（Ｓ５８で「正」）、バッファ３６に記憶されたパケットデータをクリアし、誤りがない旨をＡＣＫ／ＮＡＣＫ生成部４１に出力する。そして、ＡＣＫ／ＮＡＣＫ生成部４１はＡＣＫを生成し、変調部４２等を介して端末５０に送信する（Ｓ６１）。 Next, the error detection unit 38 detects whether or not there is an error in the received packet data (S58). When the error detection unit 38 detects that there is no error in the packet data (“correct” in S58), it clears the packet data stored in the buffer 36 and outputs to the ACK / NACK generation unit 41 that there is no error. To do. Then, the ACK / NACK generation unit 41 generates an ACK and transmits it to the terminal 50 via the modulation unit 42 and the like (S61).
　一方、誤り検出部３８は、パケットデータに誤りがあることを検出すると（Ｓ５８で「誤」）、その旨を品質測定部３９に通知し、品質測定部３９は再送回数が閾値（規定回数）を超えているか否かを判定する（Ｓ５９）。品質測定部３９は再送回数に代えて新規パケットを受信後（またはＮＡＣＫを送信後）等の経過時間をカウントし閾値（規定時間）を超えたか否かを判定してもよい。 On the other hand, when the error detection unit 38 detects that there is an error in the packet data (“error” in S58), the error measurement unit 38 notifies the quality measurement unit 39 to that effect, and the quality measurement unit 39 sets the number of retransmissions to a threshold (specified number). It is determined whether or not (S59). The quality measurement unit 39 may count elapsed time such as after receiving a new packet (or after transmitting a NACK) instead of the number of retransmissions and determine whether or not a threshold (specified time) has been exceeded.
　品質測定部３９は、再送回数が閾値を超えた場合（Ｓ５９でＹｅｓ）、ＡＣＫの生成をＡＣＫ／ＮＡＣＫ生成部４１に指示し、基地局１０からＡＣＫが送信される（Ｓ６１）。再送回数等は、例えば品質測定部３９がＡＣＫ／ＮＡＣＫ生成部４１に指示した回数等をカウントするようにしてもよい。 When the number of retransmissions exceeds the threshold (Yes in S59), the quality measurement unit 39 instructs the ACK / NACK generation unit 41 to generate ACK, and ACK is transmitted from the base station 10 (S61). As the number of retransmissions, for example, the number of times the quality measurement unit 39 has instructed the ACK / NACK generation unit 41 may be counted.
　一方、品質測定部３９は、再送回数が閾値を超えていない場合（Ｓ５９でＮｏ）、品質を判定する（Ｓ６０）。品質測定部３９は、第２の実施例のＨＡＲＱ制御部２６と同様に、「想定した伝搬路の品質」と「実際にパケットを送信したときの伝搬路の品質」とを比較する。 On the other hand, when the number of retransmissions does not exceed the threshold (No in S59), the quality measuring unit 39 determines the quality (S60). Similarly to the HARQ control unit 26 of the second embodiment, the quality measurement unit 39 compares “assumed propagation path quality” with “propagation channel quality when packets are actually transmitted”.
　例えば、過剰な品質に基づいて端末５０からパケットデータが送信されているにも関わらず、基地局１０で正常に受信していないのは、基地局１０のバッファ３６に誤ったパケットデータ（他の基地局あてのデータ等）が記憶されている可能性が高い。合成部３５によりこれまで受信したパケットデータと再送パケットとが合成され、誤り検出部３８は、合成されたデータに対して誤り検出を行う。例えば、基地局１０が受信した新規パケットデータが誤ったデータのとき、再送パケットが高品質で端末５０から送信されても、基地局１０は再送要求を繰り返す。 For example, although packet data is transmitted from the terminal 50 based on excessive quality, the base station 10 does not normally receive the packet data (other data in the buffer 36 of the base station 10). There is a high possibility that data addressed to the base station is stored. The packet data received so far and the retransmission packet are combined by the combining unit 35, and the error detection unit 38 performs error detection on the combined data. For example, when the new packet data received by the base station 10 is incorrect data, the base station 10 repeats the retransmission request even if the retransmission packet is transmitted from the terminal 50 with high quality.
　そこで、品質測定部３９は、「実際にパケットを送信したときの伝搬路の品質」が「想定した伝搬路の品質」よりも高いとき、過剰な品質によりパケットが送信されているとして、規定回数に達していなくても再送要求を停止する。規定回数に達するまで再送要求を繰り返す場合と比較して、本無線通信システム１は、遅延時間の増大を防止でき、また無線リソースを有効活用できる。 Therefore, the quality measuring unit 39 determines that the packet has been transmitted with excessive quality when the “quality of the propagation path when the packet is actually transmitted” is higher than the “assumed propagation path quality”. The retransmission request is stopped even if it has not reached. Compared with the case where the retransmission request is repeated until the specified number of times is reached, the wireless communication system 1 can prevent the delay time from increasing and can effectively use the radio resources.
　なお、品質測定部３９は、ＣＱＩ相当の品質情報を生成しているため、この品質情報をＣＱＩ相当の値として、「想定した伝搬路の品質」と「実際にパケットを送信したときの伝搬路の品質」とを演算する。 Since the quality measurement unit 39 generates quality information equivalent to CQI, the quality information is assumed to be a value equivalent to CQI, and “the quality of the assumed propagation path” and “the propagation path when the packet is actually transmitted”. Quality ".
　一方、品質測定部３９は、「想定した伝搬路の品質」の方が「実際にパケットを送信したときの伝搬路の品質」よりも高いとき（Ｓ６０でＮｏ）、ＮＡＣＫの生成をＡＣＫ／ＮＡＣＫ生成部４１に指示する（Ｓ６２）。その後、処理はＳ５１に移行し、上述した処理を繰り返す。 On the other hand, when the “assumed propagation path quality” is higher than “the propagation path quality when the packet is actually transmitted” (No in S60), the quality measurement unit 39 determines NACK generation as ACK / NACK. The generation unit 41 is instructed (S62). Thereafter, the process proceeds to S51 and the above-described process is repeated.
　図１４（Ａ）及び同図（Ｂ）はパケット等の送受信例を示す図である。これらの図に示す例は、３回目の再送パケットの送信が停止される例を示す。 FIG. 14A and FIG. 14B are diagrams showing examples of transmission / reception of packets and the like. The examples shown in these drawings show examples in which transmission of the third retransmission packet is stopped.
　端末５０のパイロット信号発生部７４は、パイロット信号を生成し基地局１０に送信する。 The pilot signal generator 74 of the terminal 50 generates a pilot signal and transmits it to the base station 10.
　基地局１０はパイロット信号を受信し、品質測定部３９は、受信したパイロット信号に基づいてＣＱＩ相当の品質情報を演算する（図１３のＳ５１）。 The base station 10 receives the pilot signal, and the quality measuring unit 39 calculates quality information corresponding to CQI based on the received pilot signal (S51 in FIG. 13).
　品質測定部３９は、誤り検出部３８から再送要求もなく（Ｓ５２で「無」）、バッファ３６にパケットデータが記憶されていないため、新規パケット有りとし（Ｓ５３で「有」）、ＣＱＩ相当の品質情報（１回目）に基づいてパケットサイズ等を決定する。（Ｓ５４～Ｓ５５）。ｇｒａｎｔ生成部４０は決定したパケットサイズ等を含むｇｒａｎｔ（１回目）を生成し、送信する（Ｓ５６）。 Since there is no retransmission request from the error detection unit 38 (“No” in S52) and no packet data is stored in the buffer 36, the quality measurement unit 39 considers that there is a new packet (“Yes” in S53) and corresponds to the CQI. The packet size and the like are determined based on the quality information (first time). (S54 to S55). The grant generation unit 40 generates and transmits grant (first time) including the determined packet size and the like (S56).
　端末５０は、ｇｒａｎｔに含まれるパケットサイズ、符号化率等に基づいて新規パケットを生成し、基地局１０に送信する。 The terminal 50 generates a new packet based on the packet size, coding rate, etc. included in the grant, and transmits it to the base station 10.
　基地局１０は、新規パケットと、端末５０が新規パケットを送信したときのパイロット信号とを受信する。品質測定部３９は、当該パイロット信号に基づいてＣＱＩ相当の品質情報（２回目）を生成し、変調方式等も決定する（Ｓ５１～Ｓ５２、Ｓ５５）。ｇｒａｎｔ生成部４０はｇｒａｎｔ（２回目のｇｒａｎｔ）を生成し、端末５０に送信する（Ｓ５６）。 The base station 10 receives a new packet and a pilot signal when the terminal 50 transmits the new packet. The quality measuring unit 39 generates quality information (second time) equivalent to CQI based on the pilot signal, and determines the modulation method and the like (S51 to S52, S55). The grant generation unit 40 generates grant (second grant) and transmits it to the terminal 50 (S56).
　品質測定部３９は、誤り検出部３８により新規パケットの誤りが検出され（Ｓ５８で「誤」）、再送回数が閾値（規定回数）に達していないため（Ｓ５９でＮｏ）、品質判定を行う（Ｓ６０）。 The quality measuring unit 39 detects the error of the new packet by the error detecting unit 38 (“false” in S58), and the quality determination is performed because the number of retransmissions has not reached the threshold (specified number) (No in S59) ( S60).
　品質測定部３９は１回目のＣＱＩ相当の品質情報を「想定した伝搬路の品質」、２回目のＣＱＩ相当の品質情報を「実際にパケットを送信したときの伝搬路の品質」とし、第２の実施例と同様に両者を比較する。この場合、品質測定部３９は、前者の方が後者よりも高い数値のため（Ｓ６０でＮｏ）、ＡＣＫ／ＮＡＣＫ生成部４１に再送要求を指示する（Ｓ６２）。基地局１０からは、ＮＡＣＫと２回目のｇｒａｎｔとが端末５０に送信される。 The quality measuring unit 39 sets the quality information equivalent to the first CQI as “assumed propagation path quality” and the quality information equivalent to the second CQI as “quality of the propagation path when the packet is actually transmitted”. Both are compared in the same manner as in the example. In this case, the quality measuring unit 39 instructs the ACK / NACK generating unit 41 to make a retransmission request because the former is a higher numerical value than the latter (No in S60) (S62). From the base station 10, NACK and second grant are transmitted to the terminal 50.
　端末５０は、２回目のｇｒａｎｔに基づいて再送パケットに対して変調等を行い、再送パケット（１回目）を送信する。 The terminal 50 modulates the retransmission packet based on the second grant, and transmits the retransmission packet (first time).
　基地局１０は、再送パケット（１回目）を受信し、端末５０が再送パケットを送信したときのパイロット信号も受信する。品質測定部３９は、当該パイロット信号に基づいてＣＱＩ相当の品質情報（３回目）を生成し、変調方式等を決定する（Ｓ５１～Ｓ５２，Ｓ５５）。また、ｇｒａｎｔ生成部４０は、ｇｒａｎｔ（３回目）を生成し端末５０に送信する（Ｓ５６）。 The base station 10 receives the retransmission packet (first time) and also receives the pilot signal when the terminal 50 transmits the retransmission packet. The quality measurement unit 39 generates quality information (third time) corresponding to CQI based on the pilot signal, and determines the modulation method and the like (S51 to S52, S55). Moreover, the grant production | generation part 40 produces | generates grant (3rd time), and transmits to the terminal 50 (S56).
　また、品質測定部３９は、再送パケットに誤りがあり（Ｓ５８で「誤」）、再送回数が規定回数に達していないため（Ｓ５９でＮｏ）、品質判定を行う（Ｓ６０）。 In addition, the quality measurement unit 39 performs quality determination because there is an error in the retransmission packet (“false” in S58) and the number of retransmissions has not reached the specified number (No in S59) (S60).
　品質測定部３９は、例えば、１回目のＣＱＩ相当の品質情報を「想定した伝搬路の品質」、２回目と３回目のＣＱＩ相当の品質情報を合成したものを「実際にパケットを送信したときの伝搬路の品質」として、両者を比較する。品質情報の合成は、例えば第２の実施例と同様に式（１）を用いる。品質情報を合成しているのは、誤り検出部３８での誤り検出が合成部３５で合成されたデータに基づいて行われるからである。この例では、前者の方が後者より高いため（Ｓ６０でＮｏ）、品質測定部３９は再送要求（２回目）を指示する（Ｓ６２）。 The quality measuring unit 39, for example, “assumed propagation path quality” for the quality information equivalent to the first CQI, and “the actual transmission of the packet” is a combination of the quality information equivalent to the second and third CQI. Both are compared as "the quality of the propagation path". For the synthesis of the quality information, for example, the expression (1) is used as in the second embodiment. The quality information is synthesized because error detection by the error detection unit 38 is performed based on the data synthesized by the synthesis unit 35. In this example, since the former is higher than the latter (No in S60), the quality measuring unit 39 instructs a retransmission request (second time) (S62).
　基地局１０は、ＮＡＣＫ（２回目）と、３回目のｇｒａｎｔとを端末５０に送信する。 The base station 10 transmits NACK (second time) and third time grant to the terminal 50.
　端末５０は、３回目のｇｒａｎｔに基づいて再送パケット（２回目）に対して変調等を行い、基地局１０に送信する。 The terminal 50 modulates the retransmission packet (second time) based on the third time grant, and transmits it to the base station 10.
　基地局１０は、再送パケットを受信し、端末５０が当該再送パケットを送信したときのパイロット信号も受信する。品質測定部３９は、当該パイロット信号に基づいて、ＣＱＩ相当の品質情報（４回目）を生成する（Ｓ５１）。ｇｒａｎｔ生成部４０はｇｒａｎｔ（４回目）を生成し、基地局１０に送信する（Ｓ５２，Ｓ５５～Ｓ５６）。 The base station 10 receives the retransmission packet and also receives a pilot signal when the terminal 50 transmits the retransmission packet. The quality measuring unit 39 generates quality information (fourth) equivalent to CQI based on the pilot signal (S51). The grant generation unit 40 generates grant (fourth time) and transmits it to the base station 10 (S52, S55 to S56).
　また、品質測定部３９は、再送パケットに誤りがあり（Ｓ５８で「誤」）、再送回数が規定回数に達していないため（Ｓ５９でＮｏ）、品質判定（Ｓ６０）を行う。 Further, the quality measuring unit 39 performs the quality determination (S60) because there is an error in the retransmission packet (“false” in S58) and the number of retransmissions has not reached the specified number (No in S59).
　この場合、品質測定部３９は、例えば、１回目のＣＱＩ相当の品質情報を「想定した伝搬路の品質」、２～４回目のＣＱＩ相当の品質情報を合成したものを「実際にパケットを送信したときの伝搬路の品質」として両者を比較する。この場合、後者の方が前者よりも高いため、品質測定部３９は、品質は過剰として、再送要求を行うことなくＡＣＫ送信を指示する（Ｓ６０でＹｅｓ，Ｓ６１）。例えば、この場合に品質測定部３９はバッファ３６をクリアにするようにしてもよい。基地局１０からはＡＣＫが送信される。品質判定については、１～３回目のＣＱＩ相当の品質情報を合成したものが「想定した伝搬路の品質」としてもよい。 In this case, the quality measuring unit 39, for example, combines the quality information equivalent to the first CQI with “assumed propagation path quality” and the quality information equivalent to the second to fourth CQI with “actual transmission of packet”. Both are compared as "the quality of the propagation path at the time." In this case, since the latter is higher than the former, the quality measuring unit 39 instructs the ACK transmission without making a retransmission request because the quality is excessive (Yes in S60, S61). For example, in this case, the quality measuring unit 39 may clear the buffer 36. An ACK is transmitted from the base station 10. As for the quality determination, a combination of quality information corresponding to the first to third CQIs may be set as “assumed propagation path quality”.
　端末５０は、ＡＣＫが返送されたため、再送パケットの送信を停止する。 Since the ACK is returned, the terminal 50 stops sending the retransmission packet.
　本第３の実施例においても、基地局１０は、図１５に示すように、再送要求を行わないことを上位レイヤ（または上位装置）４５に通知してもよい。また、品質測定部３９は、分割された周波数帯域のうち、端末５０がパケットを送信するときに用いた周波数帯域を用いて品質情報を生成するようにしてもよい（図１０）。 Also in the third embodiment, the base station 10 may notify the higher layer (or higher device) 45 that a retransmission request is not made, as shown in FIG. Further, the quality measuring unit 39 may generate the quality information using the frequency band used when the terminal 50 transmits the packet among the divided frequency bands (FIG. 10).

Claims (14)

  1. 　送信局装置と受信局装置との間で無線通信を行う無線通信システムにおいて、
    　前記送信局装置は、
    　パケットデータを前記受信局装置に送信する送信部と、
    　前記パケットデータが正しく受信できなかったことを示す応答信号を前記受信局装置から受信する受信部とを備え、　
    　前記受信局装置は、
    　前記パケットデータを受信する受信部と、
    　前記パケットデータを正しく受信できなかったとき前記応答信号を生成して前記送信局装置に送信する送信部とを備え、
    　前記送信局装置または前記受信局装置は、前記パケットデータをそれぞれ送信または受信したときの通信品質を推定し、推定した前記通信品質が所要品質よりも高いとき、それぞれ前記応答信号を受信したときまたは正しく前記パケットデータを受信できないときでも前記パケットデータの再送を行わないように制御する制御部を備えることを特徴とする無線通信システム。     In a wireless communication system that performs wireless communication between a transmitting station device and a receiving station device,
    The transmitting station device
    A transmitter for transmitting packet data to the receiving station device;
    A receiving unit that receives a response signal indicating that the packet data could not be received correctly from the receiving station device;
    The receiving station device
    A receiving unit for receiving the packet data;
    A transmission unit that generates the response signal and transmits the response signal to the transmitting station device when the packet data cannot be correctly received;
    The transmitting station device or the receiving station device estimates communication quality when the packet data is transmitted or received, respectively, and when the estimated communication quality is higher than required quality, when the response signal is received, or A wireless communication system, comprising: a control unit that controls not to retransmit the packet data even when the packet data cannot be received correctly.
  2. 　前記制御部は、前記パケットデータに対するＡＭＣパラメータ（Adaptive
    Modulation Control）を決定するための品質情報に基づいて、前記通信品質を推定することを特徴とする請求項１記載の無線通信システム。　     The control unit may use an AMC parameter (Adaptive for the packet data).
    The wireless communication system according to claim 1, wherein the communication quality is estimated based on quality information for determining (Modulation Control).
  3. 　前記制御部は、前記パケットデータの再送を行わないことを上位レイヤに通知することを特徴とする請求項１記載の無線通信システム。　 The wireless communication system according to claim 1, wherein the control unit notifies an upper layer that the packet data is not retransmitted. *
  4. 　前記制御部は、前記再送を行わないパケットデータを新規パケットデータとして送信させるよう前記送信部を制御することを特徴とする請求項１記載の無線通信システム。 The wireless communication system according to claim 1, wherein the control unit controls the transmission unit to transmit packet data that is not retransmitted as new packet data.
  5. 　前記送信局装置の送信部は、既知信号を送信し、
    　前記受信局装置の受信部は、前記既知信号を受信し、
    　前記受信局装置の送信部は、前記パケットデータを復調したときに用いた周波数帯域における既知信号を利用して品質情報を生成し、当該品質情報を前記送信局装置に送信し、
    　前記制御部は、前記品質情報に基づいて前記通信品質を推定することを特徴とする請求項１記載の無線通信システム。     The transmission unit of the transmission station device transmits a known signal,
    The receiving unit of the receiving station device receives the known signal,
    The transmitting unit of the receiving station device generates quality information using a known signal in the frequency band used when demodulating the packet data, and transmits the quality information to the transmitting station device,
    The wireless communication system according to claim 1, wherein the control unit estimates the communication quality based on the quality information.
  6. 　前記制御部は、これまでに送信した前記パケットデータの通信品質の合計により、前記通信品質を推定することを特徴とする請求項１記載の無線通信システム。 The wireless communication system according to claim 1, wherein the control unit estimates the communication quality based on a total communication quality of the packet data transmitted so far.
  7. 　前記制御部は、新規パケットのパケットデータを送信したときの通信品質を前記所要品質として推定することを特徴とする請求項１記載の無線通信システム。 The wireless communication system according to claim 1, wherein the control unit estimates the communication quality when packet data of a new packet is transmitted as the required quality.
  8. 　前記送信局装置は基地局装置、前記受信局装置は端末装置であることを特徴とする請求項１記載の無線通信システム。 The wireless communication system according to claim 1, wherein the transmitting station device is a base station device, and the receiving station device is a terminal device.
  9. 　前記送信局装置の受信部は、下り方向の通信品質を示す品質情報を前記受信局装置から受信し、
    　前記送信局装置の制御部は、前記通信品質が前記所要品質より高いとき、前記パケットデータの再送を行わないように前記送信部を制御することを特徴とする請求項８記載の無線通信システム。     The receiving unit of the transmitting station device receives quality information indicating communication quality in the downlink direction from the receiving station device,
    The radio communication system according to claim 8, wherein the control unit of the transmission station apparatus controls the transmission unit not to retransmit the packet data when the communication quality is higher than the required quality.
  10. 　前記受信局装置は基地局装置、前記送信局装置は端末装置であることを特徴とする請求項１記載の無線通信システム。 The wireless communication system according to claim 1, wherein the receiving station device is a base station device, and the transmitting station device is a terminal device.
  11. 　前記受信局装置の制御部は、前記通信品質が前記所要品質よりも高いとき、前記応答信号を送信しないように、前記受信局装置の送信部を制御することを特徴とする請求項１０記載の無線通信システム。 The control unit of the receiving station apparatus controls the transmitting unit of the receiving station apparatus so as not to transmit the response signal when the communication quality is higher than the required quality. Wireless communication system.
  12. 　受信局装置との間で無線通信を行う送信局装置において、
    　パケットデータを前記受信局装置に送信する送信部と、
    　前記パケットデータが正しく受信できなかったことを示す応答信号を前記受信局装置から受信する受信部と、
    　前記パケットデータを送信したときの通信品質を推定し、推定した前記通信品質が所要品質よりも高いとき、前記応答信号を受信したときでも前記パケットデータの再送を行わないように制御する制御部と　
    　を備えることを特徴とする送信局装置。     In the transmitting station device that performs wireless communication with the receiving station device,
    A transmitter for transmitting packet data to the receiving station device;
    A receiving unit that receives a response signal indicating that the packet data has not been correctly received from the receiving station device;
    A control unit that estimates communication quality when the packet data is transmitted, and controls the packet data not to be retransmitted even when the response signal is received when the estimated communication quality is higher than required quality;
    A transmitting station apparatus comprising:
  13. 　送信局装置との間で無線通信を行う受信局装置において、
    　前記送信局装置から送信されたパケットデータを受信する受信部と、
    　前記パケットデータを正しく受信できなかったとき前記応答信号を生成して前記送信局装置に送信する送信部と、
    　前記パケットデータを受信したときの通信品質を推定し、推定した前記通信品質が所要品質よりも高いとき、前記パケットデータを正しく受信できなかったときでも前記パケットデータの再送を行わないように制御する制御部と
    　を備えることを特徴とする受信局装置。     In the receiving station apparatus that performs wireless communication with the transmitting station apparatus,
    A receiving unit for receiving packet data transmitted from the transmitting station device;
    A transmitter that generates the response signal and transmits it to the transmitting station device when the packet data cannot be correctly received;
    Estimating the communication quality when the packet data is received, and controlling so that the packet data is not retransmitted even when the packet data is not correctly received when the estimated communication quality is higher than the required quality A receiving station apparatus comprising: a control unit.
  14. 　送信局装置と受信局装置との間で無線通信を行う無線通信システムにおける無線通信方法であって、
    　前記送信局装置は、パケットデータを前記受信局装置に送信し、
    　前記受信局装置は、前記パケットデータを正しく受信できなかったとき、正しく受信できなかったことを示す応答信号を生成して前記送信局装置に送信し、
    　前記送信局装置は、前記応答信号を前記受信局装置から受信し、
    　前記送信局装置または前記受信局装置は、前記パケットデータをそれぞれ送信または受信したときの通信品質を推定し、推定した前記通信品質が所要品質よりも高いとき、それぞれ前記応答信号を受信したときまたは正しく前記パケットデータを正しく受信できないときでも前記パケットデータの再送を行わないように制御する、
    　ことを特徴とする無線通信方法。     A wireless communication method in a wireless communication system for performing wireless communication between a transmitting station device and a receiving station device,
    The transmitting station device transmits packet data to the receiving station device;
    When the receiving station device has not received the packet data correctly, it generates a response signal indicating that the packet data has not been received correctly, and transmits the response signal to the transmitting station device.
    The transmitting station device receives the response signal from the receiving station device;
    The transmitting station apparatus or the receiving station apparatus estimates communication quality when the packet data is transmitted or received, respectively, and when the estimated communication quality is higher than required quality, when the response signal is received, or Control so as not to retransmit the packet data even when the packet data cannot be correctly received,
    A wireless communication method.
PCT/JP2009/001333 2009-03-25 2009-03-25 Radio communication system, transmission station device, reception station device, and radio communication method in radio communication system WO2010109524A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/JP2009/001333 WO2010109524A1 (en) 2009-03-25 2009-03-25 Radio communication system, transmission station device, reception station device, and radio communication method in radio communication system
JP2011505656A JPWO2010109524A1 (en) 2009-03-25 2009-03-25 Wireless communication system, transmitting station apparatus, receiving station apparatus, and wireless communication method in wireless communication system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2009/001333 WO2010109524A1 (en) 2009-03-25 2009-03-25 Radio communication system, transmission station device, reception station device, and radio communication method in radio communication system

Publications (1)

Publication Number Publication Date
WO2010109524A1 true WO2010109524A1 (en) 2010-09-30

Family

ID=42780239

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2009/001333 WO2010109524A1 (en) 2009-03-25 2009-03-25 Radio communication system, transmission station device, reception station device, and radio communication method in radio communication system

Country Status (2)

Country Link
JP (1) JPWO2010109524A1 (en)
WO (1) WO2010109524A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012134820A (en) * 2010-12-22 2012-07-12 Nec Corp Radio communication system and acquisition method for propagation path information
CN110692211A (en) * 2017-06-15 2020-01-14 富士通株式会社 Base station device, terminal device, wireless communication system, and communication method

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07123079A (en) * 1993-09-01 1995-05-12 Toshiba Corp Data transmitter
JPH09191314A (en) * 1996-01-10 1997-07-22 Mitsubishi Electric Corp Continuous data transmission method and its transmitter
JP2007194862A (en) * 2006-01-18 2007-08-02 Fujitsu Ten Ltd Method and device for data transmission

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003264873A (en) * 2002-03-08 2003-09-19 Matsushita Electric Ind Co Ltd Wireless communication apparatus and retransmission method
US6631127B1 (en) * 2002-05-29 2003-10-07 Motorola, Inc, Apparatus and method for dynamically selecting an ARQ method

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07123079A (en) * 1993-09-01 1995-05-12 Toshiba Corp Data transmitter
JPH09191314A (en) * 1996-01-10 1997-07-22 Mitsubishi Electric Corp Continuous data transmission method and its transmitter
JP2007194862A (en) * 2006-01-18 2007-08-02 Fujitsu Ten Ltd Method and device for data transmission

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012134820A (en) * 2010-12-22 2012-07-12 Nec Corp Radio communication system and acquisition method for propagation path information
CN110692211A (en) * 2017-06-15 2020-01-14 富士通株式会社 Base station device, terminal device, wireless communication system, and communication method
CN110692211B (en) * 2017-06-15 2022-06-07 富士通株式会社 Base station device and terminal device

Also Published As

Publication number Publication date
JPWO2010109524A1 (en) 2012-09-20

Similar Documents

Publication Publication Date Title
US11129144B2 (en) Integrated circuit
KR101317801B1 (en) Wireless communication having reduced feedback delay
EP1706958B1 (en) A packet data multicast communication system, a station, and a method of operating the system
KR101276396B1 (en) Transmission in a relay node-based wireless communication system
CN106230545B (en) Method and device for determining channel quality
WO2011083805A1 (en) User equipment, base station and method in mobile communication system
US8060023B2 (en) Mobile communication system, radio base station, and mobile station
EP1802021A1 (en) Data communication apparatus, data receiving apparatus, data transmitting apparatus, and retransmittal control method
US20080074999A1 (en) Mobile Communication System, Wireless Line Control Station, Mobile Station, And Wireless Base Station
JP5120252B2 (en) Mobile communication system, base station, and transmission power control method used therefor
CN103250370B (en) For strengthening the method and apparatus of downlink HARQ
US8369307B2 (en) Receiving apparatus, transmitting apparatus and communication method
JP5629982B2 (en) Wireless relay apparatus, wireless relay method, and wireless communication system
JP2006253980A (en) Method and apparatus of receiving
US8750214B2 (en) Method and base station for detecting a HARQ-ACK codeword
WO2014088861A1 (en) Method and apparatus for selectively transmitting data using spatial diversity
JP4825300B2 (en) Wireless terminal communication control method and wireless terminal
CN107690761A (en) The processing of advanced error detection code
WO2010109524A1 (en) Radio communication system, transmission station device, reception station device, and radio communication method in radio communication system
JP2012054725A (en) Base station device and antenna control method
US10361769B2 (en) Partial decode and forward (PDF) signal forwarding device with scheduler
KR100811355B1 (en) Method for requesting data transmission in radio communication system
JP2009302864A (en) Mobile terminal and data transmission method

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09842142

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2011505656

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 09842142

Country of ref document: EP

Kind code of ref document: A1