WO2017168725A1

WO2017168725A1 - Base station, wireless communication terminal device, wireless communication system, and response processing method

Info

Publication number: WO2017168725A1
Application number: PCT/JP2016/060821
Authority: WO
Inventors: 裕明渡辺
Original assignee: 富士通株式会社
Priority date: 2016-03-31
Filing date: 2016-03-31
Publication date: 2017-10-05

Abstract

On one side surface, a base station (101) is provided with a data transmission unit (603) and a response reception unit (607). The data transmission unit (603) transmits data in a first wireless band to a wireless communication terminal device (104). The response reception unit (607) receives from the wireless communication terminal device (104), in a second wireless band having a different subframe structure from the first wireless band, either a positive response or a negative response to the data transmitted in the first wireless band by the data transmission unit (603).

Description

Base station, radio communication terminal apparatus, radio communication system, and response processing method

The disclosure relates to a base station, a wireless communication terminal device, a wireless communication system, and a response processing method.

The specifications of the fifth generation mobile communication system are being studied. In the specification of the fifth generation mobile communication system, system requirements such as throughput, latency and the number of accommodated users are set higher than the specification of the fourth generation mobile communication system. As a downlink radio access scheme in the early stage of introduction of the fifth generation mobile communication system, it has been studied to succeed the LTE of the fourth generation mobile communication system and utilize OFDM in the downlink. Note that LTE is an abbreviation for Long Term Evolution, and OFDM is an abbreviation for Orthogonal Frequency Division Multiplexing.

However, it is difficult to satisfy the above system requirements in a single RAT (Radio Access Technology). Therefore, it has been studied to combine and combine a plurality of RATs having parameters optimized for each system requirement. Along with this study, the use of F-OFDM (Filtered-OFDM) as a radio access method in the fifth generation mobile communication system is currently being studied.

For example, in LTE OFDM, a fixed-length TTI or subcarrier length is used, but in the fifth generation mobile communication system, it is considered that different parameters can be selected depending on the application. However, if parameters such as TTI are mixed in the subband, the subcarriers are not orthogonal, and interference may occur between the subcarriers. Therefore, adoption of F-OFDM that allows mixing of different parameters by inserting a filter for each subband based on OFDM has been studied. Note that TTI is an abbreviation for Transmission Time Interval.

Patent Literature 1 and Patent Literature 2 can be exemplified as background art documents.

Special table 2013-541924 JP2015-165605A

Also, in the fifth generation mobile communication system, the use of a time division duplex (TDD) method is being studied. In LTE and the like, a retransmission procedure (Hybrid Automatic Repeat reQuest: HARQ) by a MAC (Media Access Control) layer is generally used. In the TDD scheme, since downlink and uplink share a frequency band, the time of downlink data from the base station to the radio communication terminal (User Equipment: UE) and the uplink response signal from the UE for the data The relationship depends on the uplink / downlink configuration. For this reason, when the length of one radio frame is 10 milliseconds, the UE response to the downlink data may be transmitted only after about 7 milliseconds, and a transmission delay of the response may occur.

In view of the above, one of the purposes of the following disclosure is to reduce the transmission delay of the response from the UE to the downlink data.

In one aspect, the base station includes a data transmission unit and a response reception unit. The data transmission unit transmits data to the wireless communication terminal device in the first wireless band. The response reception unit sends either an acknowledgment or a negative response to the data transmitted by the data transmission unit in the first radio band from the radio communication terminal apparatus to the second radio band having a subframe configuration different from that of the first radio band. Receive.

In one aspect, the wireless communication terminal device includes a data receiving unit and a response processing unit. The data receiving unit receives data from the base station in the first radio band. The response transmission unit transmits either an acknowledgment or a negative response to the data received in the first radio band to the base station in the second radio band having a subframe configuration different from that of the first radio band.

In one aspect, the wireless communication system includes a base station and a wireless communication terminal device. The base station includes a data transmission unit and a response reception unit. The data transmission unit transmits data to the wireless communication terminal device in the first wireless band. The response reception unit receives either an acknowledgment or a negative response to the data transmitted by the data transmission unit from the wireless communication terminal device in a second radio band having a subframe configuration different from that of the first radio band. The wireless communication terminal device includes a data reception unit and a response transmission unit. The data receiving unit receives data in the first radio band from the base station. The response transmission unit transmits, in the second radio band, either an acknowledgment or a negative response to the data received by the data reception unit in the first radio band.

In one aspect, the response processing method is a response processing method between a base station and a wireless communication terminal device that communicates with the base station. In the response processing method, data is transmitted from the base station to the radio communication terminal apparatus in the first radio band, and either an acknowledgment or a negative response to the data is transmitted from the radio communication terminal apparatus to the first radio band and the subframe. Transmission is performed in a second radio band having a different configuration.

According to one aspect, it is possible to reduce a transmission delay of a response from the wireless communication terminal apparatus for downlink data.

(A) is an overall view of a wireless communication system, and (B) is a diagram showing an example of a subframe configuration and an example of a transmission delay of a response to transmitted data. It is a figure which shows an example of several radio band from which a parameter differs. 1 is an overall view of a wireless communication system according to Embodiment 1. FIG. It is a figure which shows an example of the transmission delay of the response with respect to the data transmitted in one radio band of a radio band from which a sub-frame structure differs. It is a figure which shows an example of transmission of the response which concerns on Embodiment 1. FIG. 2 is a functional block diagram of a base station according to Embodiment 1. FIG. 2 is a functional block diagram of a wireless communication terminal device according to Embodiment 1. FIG. 2 is a hardware configuration diagram of a base station according to Embodiment 1. FIG. 1 is a hardware configuration diagram of a wireless communication terminal device according to Embodiment 1. FIG. 3 is a flowchart of processing of a base station according to the first embodiment. 3 is a flowchart of processing of a base station according to the first embodiment. 3 is a flowchart of processing of the wireless communication terminal device according to the first embodiment. It is a figure which shows an example of transmission of the response which concerns on Embodiment 2. FIG. 6 is a diagram illustrating an example of a control channel resource to which a wireless communication terminal device according to Embodiment 2 transmits a response. FIG. 6 is a flowchart of processing of a wireless communication terminal device according to the second embodiment.

Hereinafter, embodiments will be described with reference to the drawings. However, the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described below. In the drawings used in the following embodiments, the same reference numerals denote the same or similar parts unless otherwise specified. In addition, when a plurality of the same or similar parts appear in one drawing and are distinguished from each other, there is a case where #n (n is a natural number) is added to a sign or the like.

(Embodiment 1)
FIG. 1A is an overall view of a wireless communication system 100 according to the first embodiment. The wireless communication system 100 includes a base station 101. The base station 101 forms a wireless area 103. When the wireless communication terminal device 104 is located in the wireless area 103, a wireless link 105 is formed between the base station 101 and the wireless communication terminal device 104, and communication between the base station 101 and the wireless communication terminal device 104 becomes possible. . A link in the direction from the base station 101 to the radio communication terminal device 104 is referred to as a downlink (Down Link: DL), and a link in the direction from the radio communication terminal device 104 to the base station 101 is an uplink (Up Link: UL). May be called. In addition, data transmitted from the base station 101 to the wireless communication terminal device 104 may be referred to as downlink data.

When the downlink and uplink use the same frequency band, the downlink and uplink are used after being divided by time. In LTE TDD, for example, as an uplink / downlink configuration (UL / DL configuration) in which each of 10 subframes in a 10-millisecond radio frame is used for downlink or uplink, from # 0 Seven of # 6 are defined.

FIG. 1B is a diagram illustrating an example of an uplink / downlink configuration and an example of a transmission delay of a response to transmitted data. The uplink / downlink configuration in FIG. 1B is an uplink / downlink configuration # 3 (UL / DL configuration # 3). In FIG. 1B, PDSCH is used for downlink data transmission, and PUCCH is used for transmission of downlink data response. In the uplink / downlink configuration # 3, the 0th subframe is a downlink (D) subframe, the first subframe is a special (S) subframe, and then three uplink (U) subframes are included. Subsequently, five D subframes follow, and one radio frame is formed. PDSCH is an abbreviation for Physical Downlink Shared Channel, and PUCCH is an abbreviation for Physical Uplink Control Channel.

Note that it is possible to notify which configuration is used as the uplink / downlink configuration from the base station 101 to the wireless communication terminal device 104 by upper signaling. The higher level signaling includes system information (System Information) and radio resource setting common information element (Radio Resource Configuration Common Information Element). Also, which configuration is used as the uplink / downlink configuration can be notified by setting radio resources to each of the radio communication terminal devices 104.

In FIG. 1B, it is assumed that data 140 is transmitted from the base station 101 to the wireless communication terminal device 104 via the PDSCH in the 0th subframe 120 of the wireless frame 111. At this time, radio communication terminal apparatus 104 transmits an acknowledgment or a negative response (hereinafter referred to as a response) 141 for data reception to base station 101 in second subframe 122 of radio frame 111 via PUCCH. it can. Therefore, the transmission delay 142 from the transmission of the data 140 by the base station 101 to the transmission of the response 141 by the wireless communication terminal device 104 is, for example, about 2 milliseconds.

Meanwhile, it is assumed that data 145 is transmitted from the base station 101 to the wireless communication terminal device 104 via the PDSCH in the fifth subframe 125 of the wireless frame 111. At this time, the radio communication terminal apparatus 104 can transmit a response 146 for data reception to the base station 101 in the second subframe 132 of the radio frame 112 via the PUCCH. Therefore, the transmission delay 147 from the transmission of the data 145 by the base station 101 to the transmission of the response 146 by the wireless communication terminal device 104 is, for example, about 7 milliseconds. This is 3.5 times of the above-mentioned about 2 milliseconds, and may be a large delay time depending on the application operating on the wireless communication terminal device 104.

FIG. 2 is a diagram showing an example of F-OFDM being studied for introduction in the fifth generation mobile communication system. In the fifth generation mobile communication system, as described above, TTI, subcarrier spacing, and the like may differ between subbands (wireless bands). The TTI, subcarrier interval, and uplink / downlink configuration may be referred to as a subframe configuration. Therefore, the radio band in which any one or more of the TTI, the subcarrier interval, and the uplink / downlink configuration is different has a different subframe configuration.

Referring to FIG. 2, the subband 201 includes four subcarriers with a TTI set to 1 millisecond and an interval of 15 kHz. On the other hand, the subband 202 includes three subcarriers with a TTI set to 0.5 milliseconds and an interval of 30 kHz.

In F-OFDM, when the parameters are different between subbands, the subcarriers are not orthogonal and interference may occur between the subcarriers. In order to eliminate interference, in F-OFDM, a filter is inserted into one or both of a radio transmission unit and a radio reception unit that perform communication in each subband, and a subframe configuration between a plurality of subbands is established. Even if they are different, a plurality of subbands can be mixed. In FIG. 2, the filter is illustrated by

reference numerals

211 and 212.

FIG. 3 is a diagram illustrating an example of an overall view of the base station 101 and the wireless communication terminal device 104 when wireless links 105 and 106 having different subframe configurations are used. In other words, the wireless link 105 and the wireless link 106 are established between the base station 101 and the wireless communication terminal device 104. In this case, it is assumed that at least one of the parameters and the uplink / downlink configuration of the subband of the radio link 105 and the subband of the radio link 106 is different. In the following, the subband of the radio link 105 is denoted as “band # 1” or “radio band # 1,” and the subband of the radio link 106 is denoted as “band # 2” or “radio band # 2.” Assume that the TTI of band # 2 is shorter than the TTI of # 1.

FIG. 4 is a diagram illustrating an example of a transmission delay in response to downlink data. In other words, FIG. 4 shows that the TTI of the band # 1 is, for example, 1 millisecond, the TTI of the band # 2 is, for example, 0.5 millisecond, and the base station 101 and the wireless communication terminal device 104 are in the band # 1. It is a figure which shows an example of a transmission delay in case communication is possible using band # 2.

In FIG. 4, radio frames are arranged in the order of the radio frame 401 and the radio frame 402 in the radio band # 1. Further, in the radio band # 2, radio frames are arranged in the order of the radio frame 411, the radio frame 412, the radio frame 413, and the radio frame 414. Note that when the radio frame 401 is arranged, the radio frame 411 and the radio frame 412 are arranged, and when the radio frame 402 is arranged, the radio frame 413 and the radio frame 414 are arranged.

4, the base station 101 transmits data 440 to the wireless communication terminal device 104 via the PDSCH # 1 in the fifth subframe 425 of the wireless frame 401 in the band # 1. Further, in the seventh and

eighth subframes

427 and 428 of the radio frame 401, the base station 101 transmits

data

442 and 443 to the radio communication terminal device 104 via PDSCH # 1. In addition, in the ninth subframe 429 of the radio frame 401, the base station 101 transmits data 445 to the radio communication terminal apparatus 104 via PDSCH # 1.

In this case, a response from the wireless communication terminal device 104 to the base station 101 is transmitted as follows. The response 441 to the data 440 is transmitted in the second subframe 432 of the radio frame 402 in the band # 1. A response 444 to the

data

442 and 443 is transmitted in the third subframe 433, and a response 446 to the data 445 is transmitted in the fourth subframe 434. Accordingly, the transmission delay of the response is about 5 to 7 milliseconds.

Although not shown in FIG. 4, when similar data transmission and response transmission are performed in the band # 2 where the TTI is half of the band # 1, the response transmission delay is larger than that in the band # 1. The value is halved to approximately 2.5 milliseconds to 3.5 milliseconds. For example, it is a case where data is transmitted from the base station 101 in the radio frame 411 and a response is transmitted from the radio communication terminal apparatus 104 in the radio frame 412. Alternatively, data is transmitted from the base station 101 in the radio frame 413 and a response is transmitted from the radio communication terminal apparatus 104 in the radio frame 414. However, the band # 2 having a short TTI is not always assigned to the wireless communication terminal device 104.

Therefore, in the first embodiment, as shown in FIG. 5, the downlink data is transmitted using the band # 1, and the response is transmitted using the band # 2. The arrangement of the radio frames in FIG. 5 and FIG. 4 is the same. As shown in FIG. 5, the wireless communication terminal apparatus 104 sends a response to the data transmitted in the fifth subframe 425 of the radio frame 401 of the band # 1 to the second subframe 452 of the radio frame 412 of the band # 2. Can be sent. In this case, the response delay is about 1 millisecond.

Similarly, the wireless communication terminal apparatus 104 transmits a response to the data transmitted to the seventh and

eighth subframes

427 and 428 of the wireless frame 401 of the band # 1 in the second subframe 462 of the wireless frame 413 of the band # 2. Can be sent. In this case, the response delay is about 3 milliseconds. Similarly, the wireless communication terminal apparatus 104 can transmit a response to the data transmitted in the ninth subframe 429 of the wireless frame 401 in the band # 1 in the subframe 463 of the wireless frame 413 in the band # 2. . In this case, the response delay is about 2 milliseconds. Therefore, by transmitting a response using a band with a short TTI, it becomes possible to reduce the delay time of the response, compared with a case where both downlink data and a response are transmitted using a band with a short TTI.

FIG. 6 is a functional block diagram of the base station 101. Base station 101 includes antenna 601 and radio band transmitting / receiving units 602 # 1 and 602 # 2. The base station 101 also includes a HARQ mode determination unit 609, a HARQ mode transmission unit 610, a radio channel control unit 611, a radio channel control information creation unit 612, a user management unit 613, and a system information management / storage unit 614. And a notification information creation unit 615.

Also, each of the radio band transmission / reception units 602 # 1 and 602 # 2 includes a transmission radio unit 603, a reception radio unit 604, a demodulation / decoding unit 605, an encoding / modulation unit 606, and an HARQ information extraction unit 607. And a control information extraction unit 608.

The HARQ mode determination unit 609 sends a response to the signal received by the wireless communication terminal device 104 in the wireless band #C (for example, the wireless band # 1) in a wireless band (for example, the wireless band # 2) different from the wireless band #C. Determine whether transmission is possible. For example, when the amount of radio resources allocated to radio band #D having a TTI shorter than radio band #C is smaller than a predetermined threshold, radio communication terminal apparatus 104 responds to a signal received in radio band #C. Can be transmitted in the radio band #D having a short TTI.

Information indicating a result determined by the HARQ mode determination unit 609 may be referred to as HARQ mode information. In other words, whether the HARQ mode information can transmit a response to the signal received by the wireless communication terminal device 104 in the wireless band #C in the wireless band #D different from the wireless band #C. It expresses how. Radio band #C and radio band #D preferably have different subframe configurations. Further, it is preferable that the TTI of the radio band #D is shorter than the TTI of the radio band #C.

Downlink data transmitted from the base station 101 to the radio communication terminal apparatus 104 is transferred to the radio band transmission / reception units 602 # 1 and 602 # 2 as radio band # 1 transmission downlink data and radio band # 2 transmission downlink data. Radio band # 1 transmission downlink data and radio band # 2 transmission downlink data are multiplexed with control information generated by radio channel control information creation section 612. Also, the HARQ mode information representing the result determined by the HARQ mode determination unit 609 transmitted by the HARQ mode transmission unit 610 is multiplexed in the radio band # 1 downlink data and the radio band # 2 transmission downlink data. The multiplexed result is transferred to the encoding / modulation unit 606 of the radio band transmission / reception units 602 # 1 and 602 # 2.

The encoding / modulation unit 606 encodes and modulates the transferred data to generate a baseband signal, and transfers the baseband signal to the transmission radio unit 603. The transmission radio unit 603 converts the transferred baseband signal into a radio signal, inputs the radio signal to the antenna 601, and transmits the radio signal from the antenna 601.

The encoding / modulation unit 606 and the transmission radio unit 603 may be referred to as a data transmission unit that transmits data. Further, the data transmission unit included in the radio band transmission / reception unit 602 # 1 is said to transmit data in the first radio band, and the data transmission unit included in the radio band transmission / reception unit 602 # 2 transmits data in the second radio band. There are times when it says to send.

Also, the radio signal received by the antenna 601 is input to the reception radio unit 604. Reception radio section 604 converts the radio signal into a baseband signal and transfers the baseband signal to demodulation / decoding section 605.

The baseband signal transferred to the demodulation / decoding unit 605 is demodulated and decoded, and output as radio band # 1 reception uplink data and radio band # 2 reception uplink data. Data obtained by demodulating and decoding the baseband signal may be referred to as received data. The response included in the received data is extracted by the HARQ information extraction unit 607, and the extraction result is input to the radio channel control unit 611. The control information included in the received data is extracted by the control information extraction unit 608, and the extraction result is transferred to the wireless channel control unit 611.

Note that the HARQ information extraction unit 607 may be referred to as a response reception unit that receives a response. In addition, the response receiving unit included in the radio band transmitting / receiving unit 602 # 1 is said to receive a response in the first radio band, and the response receiving unit included in the radio band transmitting / receiving unit 602 # 2 responds in the second radio band. It may be said that it receives.

The user management unit 613 manages the attributes of the wireless communication terminal device 104 located in the base station 101. For example, subbands that can be used for communication with the wireless communication terminal device 104 are stored and managed for each wireless communication terminal device 104. Information on subbands that can be used for communication can be referred to by the HARQ mode determination unit 609 when the HARQ mode is determined.

Based on the data transferred from the HARQ information extraction unit 607, the control information extraction unit 608, and the user management unit 613, the radio channel control unit 611 transmits the transmission radio unit 603, the reception radio unit 604, the demodulation / decoding unit 605, and the encoding. Control the modulation unit 606 to control the wireless line. For example, when a negative response is transferred from the HARQ information extraction unit 607, data is retransmitted. Therefore, the HARQ information extraction unit 607 and the wireless channel control unit 611 are examples of a response processing unit that processes a response transmitted from the wireless communication terminal device 104.

Also, the radio channel control unit 611 controls the radio channel control information creation unit 612 to control creation of control information to be multiplexed into the radio band # 1 transmission downlink data and the radio band # 2 transmission downlink data. Further, the radio channel control unit 611 controls the HARQ mode determination by the HARQ mode determination unit 609. For example, information such as uplink radio resource allocation status in a shorter band of TTI is transferred to the HARQ mode determination unit 609 and controlled.

The system information management / storage unit 614 communicates with the host network and manages the system information of the wireless communication system 100. The system information management / storage unit 614 controls the notification information creation unit 615 to control generation and transmission of information to be notified to the wireless communication terminal device 104 in the area. In addition, the system information management / storage unit 614 exchanges information with the user management unit 613 and communicates with an upper network and other base stations for the handover process of the wireless communication terminal device 104.

FIG. 7 is a functional block diagram of the wireless communication terminal device 104. The wireless communication terminal device 104 includes an antenna 701 and wireless band transmission / reception units 702 # 1 and 702 # 2. Further, the wireless communication terminal device 104 includes a HARQ mode receiving unit 710, a HARQ ACK (HARQ ACKNOWLEDGEMENT) transmission instruction unit 711, a wireless channel control unit 712, and a wireless channel control information creation unit 713. The wireless communication terminal device 104 also includes a user management unit 714, a system information management / storage unit 715, and a notification information reception unit 716.

Radio band transmission / reception section 702 # 1 includes transmission radio section 703 # 1, reception radio section 704 # 1, demodulation / decoding section 705 # 1, encoding / modulation section 706 # 1, and HARQACK transmission section 707 # 1. And a reception state determination unit 708 # 1 and a control information extraction unit 709 # 1.

Radio band transmission / reception section 702 # 2 includes transmission radio section 703 # 2, reception radio section 704 # 2, demodulation / decoding section 705 # 2, encoding / modulation section 706 # 2, and HARQACK transmission section 707 # 2. And a reception state determination unit 708 # 2 and a control information extraction unit 709 # 2.

The radio signal received by the antenna 701 is transferred to the reception radio unit 704 # 1 (# 2) of the radio band transmission / reception unit 702 # 1 (# 2). Reception radio section 704 # 1 (# 2) performs subband selection and conversion to a baseband signal, and the baseband signal is transferred to demodulation / decoding section 705 # 1 (# 2).

The baseband signal transferred to the demodulation / decoding unit 705 # 1 (# 2) is subjected to decoding and demodulation processing. When user data is obtained, it is transferred to an application and a man-machine interface (not shown). Control information included in the result of decoding and demodulating the baseband signal is extracted by the control information extraction unit 709 # 1 (# 2) and transferred to the radio channel control unit 712.

The reception radio unit 704 # 1 and the demodulation / decoding unit 705 # 1 may be referred to as a first data reception unit that receives data from the base station 101 in the first radio band. In addition, reception radio unit 704 # 2 and demodulation / decoding unit 705 # 2 may be referred to as a second data reception unit that receives data from base station 101 in the second radio band.

Reception state determination section 708 # 1 (# 2) indicates whether demodulation and decoding have succeeded in demodulation / decoding section 705 # 1 (# 2) in order to transmit a response to the received data to base station 101. The information is transferred to the HARQ ACK transmission unit 707 # 1 (# 2). In other words, reception state determination section 708 # 1 (# 2) determines whether demodulation and decoding are successful. If the determination is successful, information corresponding to the positive response is transferred to HARQACK transmission units 707 # 1 and # 2, and if not successful, information corresponding to the negative response is transferred to HARQACK transmission units 707 # 1 and # 2. To do.

Each of the HARQ ACK transmission units 707 # 1 and # 2 generates data representing either an acknowledgment or a negative response according to the information transferred from the reception state determination unit 708 # 1 (# 2), and encodes it. Transfer to modulation units 706 # 1 and # 2. Note that, according to an instruction from the HARQ ACK transmission instruction unit 711, either of the HARQ ACK transmission units 707 # 1 and # 2 generates data indicating either an acknowledgment or a negative response, and the encoding / modulation unit 706 # 1 or # 2 You may come to forward to.

Note that HARQACK transmission unit 707 # 1 may be referred to as a first response transmission unit that transmits either an acknowledgment or a negative response to base station 101 in the first radio band. HARQACK transmitter 707 # 2 may be referred to as a second response transmitter that transmits either an acknowledgment or a negative response to base station 101 in the second radio band.

Based on the control information transferred from the control information extraction unit 709 # 1 (# 2), the radio channel control unit 712 transmits the transmission radio unit 703 # 1 (# 2) and the reception radio unit 704 # 1 (# 2). And the demodulator / decoder 705 # 1 (# 2) and the encoder / modulator 706 # 1 (# 2). Also, the radio channel control unit 712 is based on the control information transferred from the control information extraction unit 709 # 1 (# 2), the user management unit 714, the radio channel control information creation unit 713, and the HARQ mode reception unit 710. And control.

User management unit 714 manages information of wireless communication terminal device 104. For example, the band, time, and usable functions that the wireless communication terminal device 104 can communicate with are managed. A part of information managed by the user management unit 714 (for example, a communicable band) may be related to the control of the wireless band transmission / reception units 702 # 1 and 702 # 2 by the wireless line control unit 712.

The radio channel control information creation unit 713 generates control information to be transmitted via PUCCH or the like in accordance with control by the radio channel control unit 712. For example, the radio channel control information creation unit 713 generates control information indicating a request for radio resources and transfers the control information to the encoding / modulation unit 706 # 1 (# 2).

The HARQ mode receiving unit 710 receives HARQ mode information via the radio channel control unit 712. In addition, the HARQ mode reception unit 710 controls the HARQ ACK transmission instruction unit 711 according to the received HARQ mode information.

For example, when the HARQ mode information indicates that the response cannot be transmitted in a radio band different from the radio band in which the wireless communication terminal apparatus 104 has received the downlink data, the HARQ ACK transmission instruction unit 711 performs the following instruction. In this case, the wireless communication terminal device 104 responds in the wireless band in which the downlink data is received. HARQACK transmission section 707 # 1 transmits data representing a response when receiving information transferred from reception state determination section 708 # 1. HARQACK transmission unit 707 # 2 transmits data representing a response when receiving information transferred from reception state determination unit 708 # 2. On the other hand, even if the HARQ ACK transmission unit 707 # 1 receives the information transferred from the reception state determination unit 708 # 2, it does not transmit data representing a response. HARQACK transmission section 707 # 2 does not transmit data representing a response even if it receives information transferred from reception state determination section 708 # 1. As a result, the wireless communication terminal apparatus 104 transmits a response using the wireless band that received the data from the base station 101.

On the other hand, if the HARQ mode information indicates that the response can be transmitted in a radio band different from the radio band in which the wireless communication terminal apparatus 104 received the downlink data, the HARQ ACK transmission instruction unit 711 Give instructions. HARQACK transmission section 707 # 1 does not transmit data representing a response even if it receives information transferred from reception state determination section 708 # 1. On the other hand, when HARQACK transmission unit 707 # 2 receives information transferred from any of reception state determination units 708 # 1 and 708 # 2, it transfers data representing a response. Accordingly, when the wireless communication terminal apparatus 104 receives data from the base station 101 in the wireless band # 1, the wireless communication terminal apparatus 104 transmits a response using the wireless band # 2 having a shorter TTI.

Note that, when the wireless communication terminal device 104 transmits a response to the data received in the wireless band # 2 in the wireless band # 1, the HARQ ACK transmission unit 707 # 1 is transferred from the reception state determination unit 708 # 2. When information is received, data representing a response is transferred.

The broadcast information receiving unit 716 receives broadcast information transmitted from the base station 101 via the control information extracting unit 709 # 1 (# 2) and transfers the broadcast information to the system information management / storage unit 715.

The system information management / storage unit 715 manages and stores setting information of the wireless communication terminal device 104 and broadcast information transmitted by the base station 101.

FIG. 8 is a hardware configuration diagram of the base station. The base station 101 includes a CPU 801, a memory 802, a DSP 803, an RF circuit 804, and an NIF 805. CPU is an abbreviation for Central Proceding Unit. DSP is an abbreviation for Digital Signal Processor. RF is an abbreviation for Radio Frequency. NIF is an abbreviation for Network InterFace.

The CPU 801 is a processor capable of executing a program stored in the memory 802. According to the program, the radio channel control unit 611, the radio channel control information creation unit 612, the HARQ mode determination unit 609, the HARQ mode transmission unit 610, the user management unit 613, the system information management / storage unit 614, the broadcast information creation unit 615, etc. Function is realized.

It should be noted that, instead of the CPU 801, a function equivalent to a program can be provided by hardware using an FPGA (Field Programmable Gate Array) or the like.

The memory 802 stores a program executed by the CPU 801 and stores data necessary for executing the program. The memory 802 provides the storage function of the system information management / storage unit 614.

The DSP 803 is a processor that performs signal processing. For example, the DSP 803 has a function of processing baseband signals and extracting various information from the baseband signals. The functions of the demodulation / decoding unit 605, the encoding / modulation unit 606, the HARQ information extraction unit 607, and the control information extraction unit 608 can be realized by the DSP 803.

The RF circuit 804 is a circuit that handles radio signals. The functions of the transmission radio unit 603 and the reception radio unit 604 are realized by the RF circuit 804.

NIF 805 is an interface with the upper network. When the NIF 805 is accessed by a program executed by the CPU 801, communication with the host network can be performed.

FIG. 9 is a hardware configuration diagram of the wireless communication terminal device 104. The wireless communication terminal apparatus 104 includes a CPU 901, a memory 902, a DSP 903, an RF circuit 904, and an MMIF 905 (Man-Machine Interface).

The CPU 901 is a processor capable of executing a program stored in the memory 902. According to the program, the HARQ mode reception unit 710, the HARQ ACK transmission instruction unit 711, the radio channel control information creation unit 713, the radio channel control unit 712, the user management unit 714, the system information management / storage unit 715, and the notification A function with the information receiving unit 716 is realized.

It should be noted that, instead of the CPU 901, an FPGA or the like can be used to provide a function equivalent to a program by a hardware configuration.

The memory 902 stores a program to be executed by the CPU 901 and stores data necessary for executing the program and the FPGA. The memory provides a storage function of the system information management / storage unit 715.

The DSP 903 is a processor that performs signal processing. For example, the DSP 903 has a function of processing baseband signals and extracting various types of information from the baseband signals. The DSP 903 implements the functions of a demodulation / decoding unit 705, an encoding / modulation unit 706, a HARQACK transmission unit 707, a reception state determination unit 708, and a control information extraction unit 709.

The RF circuit 904 is a circuit that processes a radio signal. The functions of the transmission radio unit 703 and the reception radio unit 704 are realized by the RF circuit 904.

The MMIF 905 is an interface with the user of the wireless communication terminal device 104. For example, necessary information is displayed to the user via a display, or an instruction from the user is read via an input device such as a touch panel or a keyboard.

FIG. 10 is a flowchart of the processing of the base station 101. In step S <b> 1001, the HARQ mode determination unit 609 determines whether a response can be transmitted to the base station 101 using a radio band different from the radio band in which the wireless communication terminal apparatus 104 receives data. In other words, the HARQ mode determination unit 609 performs determination for generating HARQ mode information. This determination can be made for each wireless communication terminal device 104 or can be made uniformly for all the wireless communication terminal devices 104 in the area. Further, as one of the criteria for determination, it can be mentioned that the base station 101 and the wireless communication terminal device 104 are communicating in wireless bands having different TTIs. Alternatively, it may be used as another criterion for determination that there is a margin in radio resources in a radio band having a TTI shorter than a certain radio band.

In step S1001, when the HARQ mode determination unit 609 determines that it is possible, the next processing is step S1002. In step S1002, HARQ mode information is transmitted for notification that the wireless communication terminal apparatus 104 can respond using a wireless band different from the wireless band from which the data was received. If the determination in step S1001 is made for each wireless communication terminal device 104, a wireless resource is assigned to the wireless communication terminal device 104, and the wireless communication terminal device 104 is wirelessly different from the wireless band that receives the downlink data. It is possible to respond using the band. In addition, when it is determined that all wireless communication terminal devices 104 in the area are uniformly permitted, the notification information generation unit 615 notifies the determination.

If it is determined in step S1001 that the HARQ mode determination unit 609 is not possible, the next processing is step S1003. In step S1003, HARQ mode information for notifying that the wireless communication terminal apparatus 104 responds using the same wireless band as the data received wireless band is transmitted. If the determination in step S1001 is made for each wireless communication terminal device 104, a wireless resource is allocated to the wireless communication terminal device 104, and the wireless communication terminal device 104 is assigned the same wireless band as the wireless band that receives the downlink data. To make it responsive. In addition, when it is determined that it is not possible for all the wireless communication terminal devices 104 that are in the area to be uniform, the notification information generation unit 615 notifies the determination.

FIG. 11 is a flowchart of another process of the base station 101. In step S1101, the radio band transmitting / receiving unit 602 # 1 or 602 # 2 transmits data.

In step S1102, it is determined whether or not it is possible to respond using a wireless band different from the wireless band in which the wireless communication terminal apparatus 104 received data in step S1001. If it is possible, the next processing is step S1103, where the HARQ information extraction unit 607 of the radio band transmission / reception unit 602 # 1 or 602 # 2 that processes a radio band different from the radio band that transmitted the data confirms it. Determine whether a response has been received. In other words, it is determined whether or not the HARQ information extraction unit 607 has extracted an acknowledgment from a radio band different from the radio band from which the transmission radio unit 603 has transmitted a signal. If the affirmative response is extracted, the next step is S1105, and the next data after the data transmitted in step S1101 is transmitted.

In step S1103, the next process when an affirmative response is not received is step S1101, and the data is retransmitted.

In step S1102, if the wireless communication terminal apparatus 104 cannot respond using a wireless band different from the wireless band in which data is received in step S1001, the next process is step S1104. In step S1104, it is determined whether an acknowledgment has been received in the same wireless band as the wireless band that transmitted the data. The next process when an affirmative response is received is S1105. The next process when the positive response is not received is S1101.

Therefore, in this embodiment, the HARQ mode determination unit 609 and the HARQ mode transmission unit 610 notify the wireless communication terminal device 104 of a response by generating and transmitting HARQ mode information. Therefore, the HARQ mode determination unit 609 and the HARQ mode transmission unit 610 may be referred to as a notification unit.

Even in the case of branching to YES in step S1102, if the wireless resource for transmitting a response in the same wireless band as the downlink data is assigned to the wireless communication terminal apparatus 104, the same wireless band as the downlink data is assigned. May receive a response.

FIG. 12 is a flowchart of processing of the wireless communication terminal device 104. In step S <b> 1201, the HARQ mode reception unit 710 receives HARQ mode information from the radio channel control unit 712.

In step S1202, according to the HARQ mode information received by the HARQ mode reception unit 710, the HARQ ACK transmission instruction unit 711 instructs the HARQ ACK transmission units 707 # 1 and 707 # 2 to specify the HARQ mode.

Thus, when the HARQ mode information indicates that the response can be transmitted in a radio band different from the radio band in which the downlink data is received, the HARQ ACK transmission unit 707 # 2 operates as follows. HARQACK transmission section 707 # 2 forwards response corresponding to the data received by radio band transmission / reception section 702 # 1 to encoding / modulation section 706. Therefore, HARQACK transmission section 707 # 2 is an example of a response processing section that transmits a response to base station 101 in band # 2 with respect to data received from base station 101 in band # 1.

As described above, in the present embodiment, the wireless communication terminal device 104 transmits a response to the base station 101 using a wireless band with a shorter TTI. Thereby, the transmission delay of a response can be reduced and the performance of the wireless communication system 100 can be improved.

(Embodiment 2)
FIG. 13 is a diagram illustrating an example of a table indicating control channel resources to which the wireless communication terminal device according to the second embodiment transmits a response. The arrangement of the radio frames is the same as in FIG. 4 and FIG. However, as in the first embodiment, the uplink / downlink configuration of band # 1 is uplink / downlink configuration # 3, but the TTI of band # 2 is shorter than that of band # 1, and the uplink / downlink configuration is the uplink subframe configuration. The uplink / downlink configuration # 4 is smaller in number than the uplink / downlink configuration # 3. In other words, in band # 2, the third subframe is an uplink (U) subframe, and the other subframes are downlink (D) subframes or special (S) subframes.

In FIG. 13, the base station 101 transmits data 440 to the wireless communication terminal apparatus 104 via PDSCH # 1 in the fifth subframe 425 of the wireless frame 401. In addition, the base station 101 transmits

data

442, 443, and 445 to the wireless communication terminal device 104 via the PDSCH # 1 in the sixth to eighth subframes 426 to 428 of the wireless frame 401. In addition, the base station 101 transmits data 447 and 448 to the wireless communication terminal device 104 via the PDSCH # 1 in the ninth subframe 429 of the wireless frame 401 and the 0th subframe 430 of the wireless frame 402.

In this case, in the first embodiment, when the HARQ mode information indicates that the response can be transmitted in a radio band different from the radio band in which the data is received, the response from the radio communication terminal apparatus 104 to the base station 101 is It is sent as follows: The response 441 to the data 440 is transmitted in the second subframe 462 of the radio frame 412 in the band # 2, and the response 446 to the

data

442, 443, and 445 is transmitted in the second subframe 472 of the radio frame 413. .

On the other hand, the response to the data 447 and 448 is a response 450 transmitted to the second subframe 473 of the radio frame 414. However, the response 449 of the fourth subframe 434 of the radio frame 402 in the band # 1 can be transmitted earlier in time than the response 450 is transmitted.

As described above, there is a case in which it is possible to transmit the response earlier in time when the response is transmitted in the radio band in which the data is received, than in the case where the response is transmitted in a radio band different from the radio band in which the data is received. Therefore, in the present embodiment, the wireless communication terminal device 104 selects a wireless band in which a response can be transmitted earlier in time according to the combination of subframe configurations of the wireless band to be used, and transmits the response. enable.

In the present embodiment, the base station 101 uses information about a radio band including a radio band for transmitting a response from a position (subframe number) in a radio frame of a subframe as shown in FIG. To the wireless communication terminal device 104. In addition to the radio band, the HARQ mode information may include a positional relationship of subframes in the radio band for transmitting a response.

In other words, in FIG. 14, as indicated by reference numeral 1401, if the number of the subframe in which the wireless communication terminal apparatus 104 received the downlink data in band # 1 is either 0 or 9, the response is Transmit in band # 1. Further, if the number of the subframe in which the wireless communication terminal apparatus 104 received the downlink data in band # 1 is either 0 or 9, it is specified that a response is transmitted in subframe number 4 in band # 1. May be.

Also, if the number of the subframe in which the wireless communication terminal apparatus 104 received the downlink data in band # 1 is any of 5, 6, 7, and 8, a response is transmitted in band # 2. Further, if the number of the subframe in which the wireless communication terminal apparatus 104 received the downlink signal in the band # 1 is any one of 5, 6, 7, and 8, the subframe number in the band # 2 is changed to the subframe of 2. To send a response.

As described above, as shown in FIG. 14, it is possible to improve the performance of the wireless communication system 100 as compared with the first embodiment by designating the optimum wireless band for performing a response. In addition to designating the optimum radio band for performing a response, the position of the subframe in the radio band is designated, so that the number of the subframe to which the radio communication terminal apparatus 104 transmits the response is set for each downlink data. Therefore, the amount of processing can be reduced.

FIG. 15 is a flowchart for explaining processing of the wireless communication terminal device 104 in the present embodiment. This flowchart can be performed in place of the flowchart of FIG.

In step S1501, the reception wireless unit 704 of the wireless band transmission / reception unit 702 # 1 or 702 # 2 receives data. In step S1502, identification information (for example, identification information such as # 1 and # 2) of the wireless band that received the data is substituted into variable B. In step S1503, the variable S is substituted with the number of the subframe that received the radio signal. For example, when data 448 is received, 0 is substituted into the variable S.

In step S1504, it is determined whether a response to B and S is specified. If responses to B and S are designated, the next process is step S1505, and a response is made in the subframe of the designated radio band. For example, if B is 1 and S is 0, a response is made with subframe number 4 of radio band # 1 from the table of FIG.

If the response to B and S is not specified in step S1504, the next process is step S1506, and a response is made in the default subframe.

The default subframe is a subframe of a radio band in which data is received. As an example of the default subframe, there is an uplink (U) subframe after a predetermined number of subframes from the subframe of the radio band in which data is received. Alternatively, as in the first embodiment, if a response in a radio band having a shorter TTI than the subframe in the radio band in which data is received is possible, the TTI is a subframe in a shorter radio band.

As described above, in the present embodiment, the performance in the wireless communication system can be improved as compared with the first embodiment by explicitly specifying the wireless band in which the wireless communication terminal device 104 transmits a response.

In the above disclosure, the uplink / downlink configurations are described using the uplink / downlink configurations # 3 and # 4. However, the contents of the disclosure can be applied even when other uplink / downlink configurations are used. Is possible. Further, the number of radio bands having different subframe configurations may be three or more.

In the above disclosure, the base station 101 and the wireless communication terminal device 104 have been described as communicating with TDD in the wireless bands # 1 and # 2. However, for example, the base station 101 and the wireless communication terminal apparatus 104 can also be connected with FDD in the wireless band # 2. Applicable. Note that FDD is an abbreviation for Frequency Division Multiplex.

100 wireless communication system 101 base station 103 wireless area 104 wireless

communication terminal device

105, 106

wireless link

201, 202

subband

211, 212

filter

401, 402, 411, 412, 413, 414

wireless frame

425, 426, 427, 428, 429, 430, 432, 433, 434

Subframe

440, 442, 443, 445, 448

Downlink data

441, 444, 446, 449, 450 Response 601 Antenna 602 # 1, 602 # 2 Radio band transceiver 603 Transmission radio unit 604 Reception radio unit 605 Demodulation / decoding unit 606 Encoding / modulation unit 607 HARQ information extraction unit 608 Control information extraction unit 609 HARQ mode determination unit 610 HARQ mode transmission unit 611 Radio circuit control unit 612 Radio channel control information creation unit 613 User Management unit 614 system information management and storage unit 615 broadcast information generating unit 702 # 1,702 # 2 radio band transceiver 703 transmits the radio section 704 receives the radio unit 705 demodulation and decoding unit 706 coding and modulation unit 707 HARQACK transmission unit 707
708 Reception state determination unit 709 Control information extraction unit 710 HARQ mode reception unit 711 HARQ ACK transmission instruction unit 712 Radio channel control unit 713 Radio channel control information creation unit 714 User management unit 715 System information management / storage unit 716 Broadcast information reception unit 801 901 CPU
802, 902

Memory

803, 903 DSP
804, 904

RF circuit

805, 905 NIF
1401 Wireless band identifier

Claims

A data transmission unit for transmitting data to the wireless communication terminal device in the first wireless band;
The data transmission unit receives either an acknowledgment or a negative response to data transmitted in the first radio band from the radio communication terminal apparatus in a second radio band having a subframe configuration different from that of the first radio band. A response receiver
A base station.
The base station according to claim 1, wherein the TTI of the second radio band is shorter than the TTI (Transmission Time Interval) of the first radio band.
The base station according to claim 1 or 2, further comprising a notification unit that notifies the wireless communication terminal device of information related to the second wireless band.
For the information on the second radio band, the radio communication terminal apparatus transmits either the acknowledgment or the negative response for each subframe number of the data received from the base station in the first radio band. The base station according to claim 3, including designation of a radio band transmitted by the terminal device.
The information on the second radio band is a designation of a subframe number transmitted by the radio communication terminal apparatus for each of the subframe numbers of the data received by the radio communication terminal apparatus. The base station according to claim 4, comprising:
Based on the information on the second radio band by the notifying unit, the radio communication terminal device receives either an acknowledgment or a negative response to the data received from the base station in the second radio band. 6. The transmission device according to claim 3, wherein the terminal device transmits earlier in time than the wireless communication terminal device transmits either an acknowledgment or a negative response in the first wireless band. Base station.
The base station according to any one of claims 1 to 6, which performs time division duplex communication with the wireless communication terminal device.
A data receiving unit for receiving data from the base station in the first radio band;
A response for transmitting either an acknowledgment or a negative response to the data received by the data receiving unit in the first radio band to the base station in a second radio band having a subframe configuration different from that of the first radio band. A transmission unit;
A wireless communication terminal device.
The radio communication terminal apparatus according to claim 8, wherein the TTI of the second radio band is shorter than the TTI (Transmission Time Interval) of the first radio band.
The wireless communication terminal device according to claim 8 or 9, further comprising an information receiving unit that receives information related to the second wireless band.
The wireless communication according to claim 10, wherein the information on the second wireless band includes a wireless band for transmitting either the acknowledgment or the negative acknowledgment for each subframe number of the data received from the base station. Terminal device.
The radio according to claim 11, wherein the information on the second radio band includes a subframe number for transmitting either the acknowledgment or the negative acknowledgment for each subframe number of the data received from the base station. Communication terminal device.
Based on the information on the second radio band, it is more positive in the first radio band to transmit either an acknowledgment or a negative response to the data received from the base station in the second radio band. The wireless communication terminal apparatus according to any one of claims 10 to 12, which is earlier in time than transmitting either one of a response and a negative response.
The radio communication terminal apparatus according to any one of claims 8 to 13, which performs time division duplex communication with the base station.
A base station and a wireless communication terminal device,
The base station
A data transmission unit for transmitting data to the wireless communication terminal device in a first wireless band;
A response receiving unit that receives either an acknowledgment or a negative response to the data transmitted by the data transmitting unit from the wireless communication terminal device in a second wireless band having a subframe configuration different from the first wireless band;
With
The wireless communication terminal device
A data receiving unit for receiving data in the first radio band from the base station;
A response transmitter for transmitting either an acknowledgment or a negative response to the data received by the data receiver in the second radio band;
A wireless communication system.
The wireless communication system according to claim 15, wherein a TTI of the second wireless band is shorter than a TTI (Transmission Time Interval) of the first wireless band.
The base station has a notification unit that notifies the wireless communication terminal device of information related to the second wireless band,
The wireless communication system according to claim 15 or 16, wherein the wireless communication terminal device includes an information receiving unit that receives information related to the second wireless band.
For the information on the second radio band, the radio communication terminal apparatus transmits either the acknowledgment or the negative response for each subframe number of the data received from the base station in the first radio band. The wireless communication system according to claim 17, comprising designation of a wireless band transmitted by the terminal device.
The information on the second radio band is a designation of a subframe number transmitted by the radio communication terminal apparatus for each of the subframe numbers of the data received by the radio communication terminal apparatus. The wireless communication system according to claim 18, comprising:
The wireless communication terminal device sends either an acknowledgment or a negative response to the data received from the base station by the wireless communication terminal device based on the information on the second wireless band by the base station. 20. The wireless communication terminal device that transmits in a wireless band is earlier in time than the wireless communication terminal device transmits either an acknowledgment or a negative response in the first wireless band. The wireless communication system according to any one of the above.
The wireless communication system according to any one of claims 15 to 20, wherein the base station and the wireless communication terminal device perform time division duplex communication.
A response processing method between a base station and a wireless communication terminal device communicating with the base station,
From the base station, transmit data to the wireless communication terminal device in a first wireless band,
A response processing method in which either an acknowledgment or a negative response to the data is transmitted from the wireless communication terminal apparatus in a second wireless band having a subframe configuration different from that of the first wireless band.
The response processing method according to claim 22, wherein a TTI of the second radio band is shorter than a TTI (Transmission Time Interval) of the first radio band.
The response processing method according to claim 22 or 23, wherein the base station notifies the wireless communication terminal device of information related to the second wireless band.
The information on the second radio band is a radio that transmits either the acknowledgment or the negative acknowledgment for each subframe number of data that the radio communication terminal apparatus receives from the base station in the first radio band. The response processing method according to claim 24, further comprising designation of a band.
The information on the second radio band is a sub-transmission for transmitting either the acknowledgment or the negative acknowledgment for each subframe number of data received by the radio communication terminal apparatus from the base station in the first radio band. 26. The response processing method according to claim 25, including designation of a frame number.
Based on the information about the second radio band, the radio communication terminal apparatus transmits either an acknowledgment or a negative response to the data received from the base station in the second radio band. The response processing method according to any one of claims 24 to 26, wherein the communication terminal device is earlier in time than transmitting either an acknowledgment or a negative response in the first radio band.
The response processing method according to any one of claims 22 to 27, wherein the base station and the wireless communication terminal apparatus perform time division duplex communication.