JP2020123983A - Communication apparatus, radio communication system, and radio communication method - Google Patents

Abstract

To provide a communication apparatus, a radio communication system, and a radio communication method capable of improving the communication efficiency of the radio communication system.SOLUTION: In the mobile telephone system, a communication apparatus 11 determines the applicability of retransmission control based on either communication status, communication volume, or type of data to be transmitted relevant to radio communication with a communication apparatus 12 (S101). The communication apparatus 11 generates a control signal that includes a piece of information that indicates whether retransmission control should be applied and transmits the control signal to the communication apparatus 12 (S102). On the other hand, receiving the control signal, the communication apparatus 12 controls the application of the retransmission control according to the information that represents the applicability of the retransmission control included in the control signal (S103). The communication apparatus 11 and the communication apparatus 12 executes the radio communication depending on the control result of applying retransmission control (S104).SELECTED DRAWING: Figure 2

Description

The present invention relates to, for example, a communication device that performs wireless communication, a wireless communication system, and a wireless communication method.

In a wireless communication system such as a mobile communication system, data communicated on the wireless communication system due to an increase in the number of connected communication terminals, improvement in quality of transmitted data, or diversification of services provided The quantity is increasing. Therefore, in order to increase the communication capacity of the wireless communication system, various technologies have been developed and standardized as a standard of the wireless communication system (for example, see Non-Patent Documents 1 to 11).

3GPP TS36.300 v13.3.0, March 2016 3GPP TS36.211 v13.1.0, March 2016 3GPP TS36.212 v13.1.0, March 2016 3GPP TS36.213 v13.1.1, March 2016 3GPP TS36.321 v13.1.0, March 2016 3GPP TS36.322 v13.1.0, March 2016 3GPP TS36.323 v13.1.0, March 2016 3GPP TS36.331 v13.1.0, March 2016 3GPP TS36.413 v13.2.0, March 2016 3GPP TS36.423 v13.3.0, March 2016 3GPP TS36.881 v0.6.0, February 2016

However, the amount of data transmitted over wireless communication systems can grow ever more. Therefore, it is required to improve the communication efficiency of the wireless communication system.

In one aspect, the present invention aims to provide a communication device capable of improving the communication efficiency of a wireless communication network.

According to one embodiment, a communication device is provided. This communication device includes a wireless processing unit that transmits or receives a wireless signal and information that is included in a wireless signal received from another communication device via the wireless processing unit and that indicates whether to apply retransmission control. Accordingly, the control unit controls the application of retransmission control.

According to another embodiment, there is provided a wireless communication system having a first communication device and a second communication device. In this wireless communication system, the first communication device transmits a wireless signal including information indicating whether to apply retransmission control to the second communication device, and the second communication device responds to the information. Control the application of retransmission control.

According to another embodiment, a wireless communication method in a wireless communication system having a first communication device and a second communication device is provided. In this wireless communication method, the first communication device transmits a wireless signal including information indicating whether or not to apply retransmission control to the second communication device, and the second communication device responds to the information. It includes controlling the application of retransmission control.

According to yet another embodiment, a communication device is provided. This communication device is a wireless processing unit that transmits or receives a wireless signal and a communication state of wireless communication with another communication device, a communication amount, or data transmitted between the communication device and another communication device. Determine whether to apply the retransmission control based on at least one of the types, generate a wireless signal including information indicating whether to apply the retransmission control based on the determination result, and wirelessly generate the wireless signal. It has a control part which transmits to another communication apparatus via a processing part.

The communication device disclosed in this specification can improve communication efficiency of a wireless communication system.

FIG. 1 is a schematic configuration diagram of a wireless communication system according to the first embodiment. FIG. 2 is an operation sequence diagram of communication processing relating to retransmission control. FIG. 3 is a schematic configuration diagram of one communication device included in the wireless communication system according to the first embodiment. FIG. 4 is a functional block diagram of a control unit of one communication device related to retransmission control. FIG. 5 is an operation flowchart of one communication device regarding retransmission control. FIG. 6 is a schematic configuration diagram of the other communication device included in the wireless communication system according to the first embodiment. FIG. 7 is an operation flowchart of the other communication device regarding retransmission control. FIG. 8 is a schematic configuration diagram of a wireless communication system according to the second embodiment. FIG. 9 is a schematic configuration diagram of the base station. FIG. 10 is a schematic configuration diagram of a mobile station. FIG. 11A is a diagram showing an example of the structure of data transmitted in an uplink signal when retransmission control is applied, and FIG. 11B is an uplink when retransmission control is not applied. It is a figure which shows an example of the structure of the data transmitted by a signal. FIG. 11C is a diagram showing another example of the structure of the data transmitted by the uplink signal.

Hereinafter, a communication device, a wireless communication system, and a communication method will be described with reference to the drawings.
Hybrid automatic repeat request (HARQ) is adopted in so-called Long Term Evolution (LTE), Worldwide Interoperability for Microwave Access (WiMAX), which is one of the mobile communication standards. HARQ is one of the technologies related to retransmission control in which the communication device on the transmission side retransmits the data when the communication device on the reception side cannot reproduce the data correctly, and combines the forward error correction code and the automatic retransmission request. It is a thing. In HARQ, a communication device on the receiving side, for example, a base station is a communication device on the transmitting side, for example, to notify the communication device on the transmitting side whether or not the data received from the mobile station can be normally reproduced, an Ack signal or Nack Send a signal. Then, the communication device on the transmission side that has received the Nack signal divides the data into individual parts and retransmits them. As a result, the communication device on the receiving side can normally reproduce data that could not be reproduced normally.

However, depending on the type of data, there is also traffic (Low Latency Communication Traffic, LLC Traffic) with a low tolerance for delay, although a certain transmission error is tolerated. Regarding LLC Traffic, suppressing the delay may be prioritized over suppressing the transmission error, and in such a case, retransmission control may not be performed.

Regarding the uplink, a contention based physical uplink shared channel (CB-PUSCH) is under study. Then, transmission of LLC Traffic data using CB-PUSCH is being considered. In such a case, when HARQ is applied, although the retransmission control is unnecessary, the transmission of the Ack signal or the Nack signal is performed, so that the communication efficiency in wireless communication is reduced.

Therefore, according to the present embodiment, one communication device, for example, based on at least one of the communication state, the communication amount or the type of data to be transmitted, determines whether to apply the retransmission control, The applicability is notified to the other communication device. The other communication device controls the application of the retransmission control according to the notification. When the retransmission control is applied, the other communication device attaches the error detection code related to the retransmission control to the transmitted signal, and when the retransmission control is not applied, the other communication device transmits the error detection code. Not attached to transmitted signals. As a result, the communication device and the wireless communication system including such a communication device improve communication efficiency.

In this specification, the base station and the mobile station are examples of communication devices. Also, Node B, eNode B, new eNode B, access point, etc. are examples of base stations. Furthermore, a mobile terminal or User Equipment (UE) is an example of a mobile station. Further, in the present specification, HARQ, Automatic repeat-request (ARQ) and the like are examples of retransmission control. Then, the error detection code related to the retransmission control is used in the communication device on the receiving side to determine whether or not to perform the retransmission request, depending on whether or not the received data is normally reproduced. This is an error detection code. The error detection code also includes an error correction code.

FIG. 1 is a schematic configuration diagram of a wireless communication system according to the first embodiment. The wireless communication system 1 includes a communication device 11 and a communication device 12. The communication device 11 and the communication device 12 transmit signals to each other by wireless communication. Note that either one or both of the communication device 11 and the communication device 12 may be a mobile terminal, or may be a fixed communication device.

The communication device 11 transmits the communication state or communication amount of wireless communication between the communication device 11 and the communication device 12, or between the communication device 11 and the communication device 12 at regular intervals or at predetermined timing. Applicability of retransmission control is determined according to the type of data.

Each time the communication device 11 determines the applicability of the retransmission control, the communication device 11 generates a control signal including information indicating the applicability of the retransmission control, and transmits the control signal to the communication device 12. In addition, in the wireless communication with the communication device 12, the communication device 11 controls the application of the retransmission control according to the determination result of the applicability. That is, when the retransmission control is not applied, the communication device 11 transmits a response signal such as Ack/Nack regardless of whether or not the data included in the wireless signal received from the communication device 12 is normally reproduced. Do not send to.

On the other hand, when the retransmission control is applied, the communication device 11 executes error detection processing according to the error detection code attached to the wireless signal on the wireless signal according to the application of the retransmission control. It is determined whether or not the data included in the wireless signal is normally reproduced. Then, the communication device 11 transmits a different response signal to the communication device 12 depending on whether or not the data included in the wireless signal received from the communication device 12 is normally reproduced. For example, when the data included in the wireless signal received from the communication device 12 is normally reproduced, the communication device 11 transmits an Ack signal to the communication device 12. On the other hand, when the data included in the wireless signal received from the communication device 12 is not normally reproduced, the communication device 11 transmits the Nack signal to the communication device 12. As the error detection code, for example, a Cyclic Redundancy Check (CRC) code is used.

On the other hand, every time the communication device 12 receives from the communication device 11 a control signal including information indicating the applicability of retransmission control, the communication device 12 refers to the information and controls the application of retransmission control. That is, if the received control signal includes information indicating that retransmission control is not applied, the communication device 12 does not apply retransmission control. In this case, the communication device 12 does not attach the error detection code related to the retransmission control to the radio signal transmitted to the communication device 11. Further, in this case, since the communication device 12 does not need to store the data included in the wireless signal transmitted to the communication device 11 in the storage unit of the communication device 12 for retransmission, after transmitting the wireless signal, the wireless signal is transmitted. The data contained in may be discarded.

On the other hand, if the received control signal includes information indicating that the retransmission control is applied, the communication device 12 applies the retransmission control. In this case, the communication device 12 attaches an error detection code related to retransmission control to the radio signal transmitted to the communication device 11. Further, the communication device 12 retransmits the data included in the wireless signal transmitted to the communication device 11 until it is confirmed that the data transmitted on the communication device 11 side is normally reproduced or until a certain period of time elapses. For this purpose, it is stored in the storage unit of the communication device 12. Then, when the communication device 12 receives a signal requesting retransmission from the communication device 11 (for example, a Nack signal), the communication device 12 retransmits a wireless signal including a part or all of data corresponding to the signal.

FIG. 2 is an operation sequence diagram of communication processing relating to retransmission control according to this embodiment.
The communication device 11 determines whether or not to apply the retransmission control based on any one of the communication state, the communication amount, and the type of data to be transmitted regarding the wireless communication with the communication device 12 (step S101). Then, the communication device 11 generates a control signal including information indicating whether or not retransmission control is applicable, and transmits the control signal to the communication device 12 (step S102).

On the other hand, when the communication device 12 receives the control signal, the communication device 12 controls the application of the retransmission control according to the information indicating whether the retransmission control is included in the control signal (step S103). Then, the communication device 11 and the communication device 12 execute wireless communication according to the control result of the application of the retransmission control (step S104).

FIG. 3 is a schematic configuration diagram of the communication device 11. The communication device 11 includes an antenna 21, a wireless processing unit 22, a storage unit 23, and a control unit 24. The wireless processing unit 22, the storage unit 23, and the control unit 24 are formed as separate circuits. Alternatively, each of these units may be mounted on the communication device 11 as one or a plurality of integrated circuits in which circuits corresponding to the respective units are integrated.

The antenna 21 transmits the transmission signal transmitted via the wireless processing unit 22 as a wireless signal. Further, the antenna 21 receives a wireless signal from the communication device 12, converts the wireless signal into an electric signal to form a received signal, and transmits the received signal to the wireless processing unit 22. The antenna 21 may have an antenna for transmission and an antenna for reception separately.

The wireless processing unit 22 converts the transmission signal received from the control unit 24 into an analog signal, and then superimposes it on a carrier wave having a wireless frequency designated by the control unit 24. Then, the wireless processing unit 22 amplifies the transmission signal superimposed on the carrier wave to a desired level by a high power amplifier (not shown), and transmits the transmission signal to the antenna 21.

Further, the wireless processing unit 22 amplifies the received signal received from the antenna 21 with a low noise amplifier (not shown). The radio processing unit 22 multiplies the amplified received signal by a periodic signal having an intermediate frequency to convert the frequency of the received signal from the radio frequency to the baseband frequency. Then, the wireless processing unit 22 performs analog/digital conversion on the received signal having the baseband frequency, and then passes it to the control unit 24.

The storage unit 23 has, for example, a rewritable nonvolatile semiconductor memory or a volatile semiconductor memory. The storage unit 23 stores various types of information for communicating with the communication device 12, various types of information transmitted or received by the communication device 11, various types of programs operating on the communication device 11, and the like. Further, the storage unit 23 stores various kinds of information used for determining whether or not the retransmission control is applicable.

The control unit 24 has, for example, one or a plurality of processors and their peripheral circuits. Then, the control unit 24 modulates and multiplexes the transmission signal according to a predetermined modulation method. Then, the control unit 24 passes the modulated and multiplexed transmission signal to the wireless processing unit 22.

On the other hand, the control unit 24 separates the received signals received from the wireless processing unit 22 according to a predetermined multiplexing method, and demodulates the separated received signals, respectively. Then, the control unit 24 extracts various control information or data included in the demodulated received signal. Then, the control unit 24 executes processing according to the extracted control information or data.

Furthermore, the control unit 24 executes various processes for executing wireless communication, such as transmission power control and call control.

Further, the control unit 24 executes various kinds of processing for determining the applicability of retransmission control.
FIG. 4 is a functional block diagram of the control unit 24 related to the retransmission control. The control unit 24 has a retransmission control unit 241, a notification unit 242, and a retransmission control execution unit 243. Each of these units included in the control unit 24 is realized by a computer program operating on a processor included in the control unit 24. Alternatively, each of these units included in the control unit 24 may be implemented in the communication device 11 separately from the processor included in the control unit 24, as one or a plurality of integrated circuits in which circuits that implement the functions of the respective units are integrated. Good.

The retransmission control unit 241 determines whether or not the retransmission control can be applied depending on the communication state or communication amount of wireless communication between the communication device 11 and the communication device 12 or the type of data transmitted between the communication device 11 and the communication device 12. To decide.

For example, the retransmission control unit 241 may determine not to apply the retransmission control when the value of the parameter indicating the wireless quality of the wireless signal received from the communication device 12 satisfies a predetermined quality standard. On the other hand, the retransmission control unit 241 may determine to apply the retransmission control when the value of the parameter indicating the wireless quality does not satisfy the predetermined quality standard.

Alternatively, the retransmission control unit 241 determines not to apply the retransmission control when the amount of data transmitted at one time is less than or equal to a predetermined threshold, while the amount of data transmitted at one time is greater than the predetermined threshold. It may be decided to apply the retransmission control to. Alternatively, the retransmission control unit 241 determines not to apply the retransmission control when the relative movement speed of the communication device 12 with respect to the communication device 11 is equal to or lower than a predetermined threshold, while the relative movement speed is predetermined. It may be determined that the retransmission control is applied when it is faster than the threshold. Alternatively, when the communication device 11 can set a plurality of communicable ranges, when the communication device 12 moves from one communicable range to another communicable range within the latest predetermined period, the retransmission control unit 241. May decide to apply retransmission control. On the other hand, when the communication device 12 remains within one of the communicable ranges within the latest predetermined period, the communication device 11 may determine not to apply the retransmission control.

Further, when the data transmitted from the communication device 12 to the communication device 11 is LLC Traffic data such as streaming data and voice call data, the retransmission control unit 241 determines not to apply the retransmission control. Good. The retransmission control unit 241 also performs retransmission control when the data transmitted from the communication device 12 to the communication device 11 is data transmitted at a constant cycle, such as Internet of Things (IoT) data. You may decide not to apply. On the other hand, if the data transmitted from the communication device 12 to the communication device 11 is the data required to be normally reproduced by the communication device 11 or a device to which the data is transferred via the communication device 11, the data is retransmitted. The control unit 241 may determine to apply the retransmission control.

Furthermore, the retransmission control unit 241 may determine the applicability of the retransmission control based on, for example, a combination of two or more of the communication state, the communication amount, and the data type. For example, the retransmission control unit 241 determines to apply the retransmission control when the condition for applying the retransmission control is satisfied with respect to any of the above examples of some parameters, and in other cases, You may decide not to apply retransmission control.

The retransmission control unit 241 notifies the notification unit 242 and the retransmission control execution unit 243 of information indicating whether or not retransmission control is applicable.

The notification unit 242 generates a control signal including information indicating the applicability of the retransmission control every time the retransmission control unit 241 determines the applicability of the retransmission control. The control signal is an example of a transmission signal transmitted from the communication device 11 to the communication device 12. Then, the notification unit 242 transmits the control signal to the communication device 12 via the wireless processing unit 22 and the antenna 21.

The retransmission control execution unit 243 executes retransmission control.
FIG. 5 is an operation flowchart of the communication device 11 regarding retransmission control, which is executed by the retransmission control execution unit 243.

The retransmission control execution unit 243 determines whether or not the retransmission control is applied, based on the information indicating whether or not the retransmission control is applicable, notified from the retransmission control unit 241 (step S201). When the retransmission control is applied (step S201-Yes), the retransmission control execution unit 243 responds to the error detection code added to the data included in the received signal from the communication device 12 according to the application of the retransmission control. Perform error detection processing on the data. Then, the retransmission control execution unit 243 determines whether the data is normally reproduced (step S202). Then, the retransmission control execution unit 243 generates a different response signal depending on whether or not the data included in the received signal is normally reproduced. For example, when the data included in the received signal is normally reproduced (step S202-Yes), the retransmission control execution unit 243 generates an Ack signal and communicates the Ack signal via the wireless processing unit 22 and the antenna 21. The data is transmitted to the device 12 (step S203).

On the other hand, when the data included in the received signal is not normally reproduced (step S202-No), the retransmission control execution unit 243 generates a Nack signal, and the Nack signal is transmitted to the communication device via the wireless processing unit 22 and the antenna 21. 12 (step S204). The Nack signal is an example of a retransmission request signal that requests the communication device 12 to retransmit data. Then, the retransmission control execution unit 243 uses the data retransmitted according to the retransmission control adopted by the wireless communication system 1 to reproduce the data included in the original received signal (step S205). It should be noted that the retransmission control execution unit 243 may repeat the processing from step S202 onward, if necessary.

On the other hand, when the retransmission control is not applied in step S201 (step S201-No), the retransmission control execution unit 243 does not execute the retransmission control. Therefore, the retransmission control execution unit 243 does not generate a response signal such as Ack/Nack regardless of whether the data included in the reception signal received from the communication device 12 is normally reproduced.

FIG. 6 is a schematic configuration diagram of the communication device 12. The communication device 12 includes an antenna 31, a wireless processing unit 32, a storage unit 33, and a control unit 34. The wireless processing unit 32, the storage unit 33, and the control unit 34 are formed as separate circuits. Alternatively, each of these units may be mounted on the communication device 12 as one or a plurality of integrated circuits in which circuits corresponding to the respective units are integrated.

The antenna 31 transmits the transmission signal transmitted via the wireless processing unit 32 as a wireless signal. Further, the antenna 31 receives a wireless signal from the communication device 11, converts the wireless signal into an electric signal to form a received signal, and transmits the received signal to the wireless processing unit 32. Note that the antenna 31 may have a transmitting antenna and a receiving antenna separately.

The wireless processing unit 32 converts the transmission signal received from the control unit 34 into an analog signal, and then superimposes it on a carrier wave having a wireless frequency designated by the control unit 34. Then, the wireless processing unit 32 amplifies the transmission signal superimposed on the carrier wave to a desired level by a high power amplifier (not shown), and transmits the transmission signal to the antenna 31.

Further, the wireless processing unit 32 amplifies the reception signal received from the antenna 31 by a low noise amplifier (not shown). The radio processing unit 32 multiplies the amplified received signal by a periodic signal having an intermediate frequency to convert the frequency of the received signal from the radio frequency to the baseband frequency. Then, the wireless processing unit 32 performs analog/digital conversion on the received signal having the baseband frequency, and then passes it to the control unit 34.

The storage unit 33 includes, for example, a rewritable nonvolatile semiconductor memory or a volatile semiconductor memory. The storage unit 33 stores various kinds of information for communicating with the communication device 11, various kinds of information transmitted or received by the communication device 12, and various programs operated by the communication device 12. Further, the storage unit 33 stores various kinds of information used for executing the retransmission control. Further, the storage unit 33 stores the once-transmitted transmission signal for a certain period when the retransmission control is applied.

The control unit 34 has, for example, one or a plurality of processors and their peripheral circuits. Then, the control unit 34 modulates and multiplexes the transmission signal according to a predetermined modulation method. Then, the control unit 34 passes the modulated and multiplexed transmission signal to the wireless processing unit 32.

On the other hand, the control unit 34 separates the received signals received from the wireless processing unit 32 according to a predetermined multiplexing method, and demodulates the separated received signals, respectively. Then, the control unit 34 extracts various control information or data included in the demodulated received signal. Then, the control unit 34 executes processing according to the extracted control information or data.

Further, the control unit 34 executes various processes for executing wireless communication, such as transmission power control and call control.

Further, every time the control unit 34 receives from the communication device 11 a control signal including information indicating the applicability of retransmission control, the control unit 34 refers to the information and controls the application of retransmission control.
FIG. 7 is an operation flowchart of the communication device 12 relating to retransmission control executed by the control unit 34.

The control unit 34 determines whether the received control signal includes information indicating that retransmission control is applied (step S301).

If the received control signal includes information indicating that retransmission control is applied (Yes at step S301), the control unit 34 applies retransmission control. In this case, the control unit 34 attaches an error detection code related to retransmission control to the data included in the transmission signal to be transmitted to the communication device 11, and generates the transmission signal (step S302). Then, the control unit 34 transmits the transmission signal to the communication device 11 via the wireless processing unit 32 and the antenna 31.

In addition, the control unit 34 retransmits the data included in the transmission signal transmitted to the communication device 11 until it is confirmed that the data transmitted on the communication device 11 side is normally reproduced or until a certain period of time elapses. For this purpose, the data is stored in the storage unit 33 (step S303). When the control unit 34 receives a signal requesting retransmission from the communication device 11 (for example, a Nack signal), the control unit 34 generates a transmission signal for retransmission including some or all of the data included in the transmission signal. The control unit 34 transmits the generated transmission signal to the communication device 11 via the wireless processing unit 32 and the antenna 31 (step S304).

On the other hand, in step S301, if the received control signal includes information indicating that retransmission control is not applied (step S301-No), the control unit 34 does not apply retransmission control. In this case, the control unit 34 generates the transmission signal without adding the error detection code related to the retransmission control to the data included in the transmission signal transmitted to the communication device 11 (step S305). Then, the control unit 34 transmits the transmission signal to the communication device 11 via the wireless processing unit 32 and the antenna 31. Further, in this case, the control unit 34 may discard the data included in the transmission signal transmitted to the communication device 11 without storing the data in the storage unit 33.

As described above, in this wireless communication system, one communication device determines the applicability of the retransmission control and notifies the other communication device of the applicability. Then, the other communication device controls the application of the retransmission control according to the notification. Therefore, this wireless communication system can dynamically switch whether or not to apply the retransmission control, so that it is possible to suppress a decrease in communication efficiency due to the retransmission control when it is not necessary to apply the retransmission control. As a result, the wireless communication system and each communication device included in the wireless communication system can improve communication efficiency.

Next, a wireless communication system according to the second embodiment will be described. This wireless communication system has a base station and a mobile station. Then, the base station determines whether or not to apply the retransmission control based on the communication state or the amount of communication of wireless communication with the mobile station, and transmits a control signal including information indicating the applicability to the mobile station. The mobile station controls the application of retransmission control according to the information.

FIG. 8 is a schematic configuration diagram of a wireless communication system according to the second embodiment. The wireless communication system 2 according to the second embodiment includes a base station 41 and a mobile station 42. The base station 41 and the mobile station 42 are examples of communication devices. Further, the number of base stations included in the wireless communication system 2 is not limited to one and may be plural. Similarly, the number of mobile stations included in the wireless communication system 2 is not limited to one and may be plural.

The base station 41 and the mobile station 42 execute communication processing related to retransmission control according to the operation sequence shown in FIG. In the present embodiment, the communication device 11 in FIG. 2 may be used as the base station 41, and the communication device 12 may be used as the mobile station 42 to execute communication processing relating to retransmission control.

That is, the base station 41, like the communication device 11 in the first embodiment, has a communication state or a communication volume of wireless communication between the base station 41 and the mobile station 42 at regular intervals or at a predetermined timing. Whether or not to apply the retransmission control is determined according to. The predetermined timing may be, for example, a handover or a connection request.

Each time the base station 41 determines whether to apply the retransmission control, the base station 41 generates a control signal including information indicating whether the retransmission control is applicable, and transmits the control signal to the mobile station 42. Further, the base station 41 controls the application of the retransmission control in the wireless communication with the mobile station 42 according to the determination result of the applicability. That is, when retransmission control is not applied, the base station 41 transmits a response signal such as Ack/Nack to the communication device regardless of whether the data included in the uplink signal received from the mobile station 42 is normally reproduced. Do not send to 12.

On the other hand, when retransmission control is applied, the base station 41 performs error detection processing according to the error detection code attached to the wireless signal on the wireless signal according to the application of the retransmission control. It is determined whether or not the data included in the wireless signal is normally reproduced. Then, the base station 41 transmits a different response signal to the mobile station 42 depending on whether or not the data included in the uplink signal received from the mobile station 42 is normally reproduced.

On the other hand, each time the mobile station 42 receives a downlink control signal including information indicating whether or not retransmission control is applicable from the base station 41, the mobile station 42 refers to that information, as in the communication device 12 in the first embodiment. Then, the application of retransmission control is controlled. That is, if the received control signal includes information indicating that retransmission control is not applied, the mobile station 42 does not apply retransmission control. In this case, the mobile station 42 does not attach the error detection code related to the retransmission control to the data included in the uplink signal transmitted to the base station 41. Further, in this case, since the data included in the uplink signal already transmitted to the base station 41 is not retransmitted, the mobile station 42 discards the data included in the already transmitted uplink signal without storing it in the storage unit. May be.

On the other hand, if the received control signal includes information indicating that retransmission control is applied, the mobile station 42 applies retransmission control. In this case, the mobile station 42 attaches an error detection code related to retransmission control to the uplink signal transmitted to the base station 41. In addition, the mobile station 42 retransmits the data included in the uplink signal transmitted to the base station 41 until it is confirmed that the data transmitted from the base station 41 side is normally reproduced or until a certain period of time elapses. It is stored in the storage unit for. Then, when the mobile station 42 receives a signal requesting retransmission from the base station 41 (for example, a Nack signal), it retransmits part or all of the data corresponding to the signal.

When there are a plurality of mobile stations connected to the base station 41, the base station 41 may determine whether to apply retransmission control for each mobile station. Then, the base station 41 may notify each mobile station of a control signal including information indicating whether or not retransmission control is applicable to the mobile station.

FIG. 9 is a schematic configuration diagram of the base station 41. The base station 41 includes an antenna 51, a wireless processing unit 52, a wired interface unit 53, a storage unit 54, and a control unit 55. The wireless processing unit 52, the storage unit 54, and the control unit 55 are formed as separate circuits. Alternatively, each of these units may be implemented in the base station 41 as one or a plurality of integrated circuits in which circuits corresponding to the respective units are integrated.

The antenna 51 transmits the downlink signal transmitted via the wireless processing unit 52 as a wireless signal. Further, the antenna 51 receives a radio signal from the mobile station 42, converts the radio signal into an electric signal into an uplink signal, and transmits the uplink signal to the radio processing unit 52. Note that the antenna 51 may have a transmitting antenna and a receiving antenna separately.

The radio processing unit 52 converts the downlink signal received from the control unit 55 into an analog signal, and then superimposes the downlink signal on a carrier wave having a radio frequency designated by the control unit 55. Then, the wireless processing unit 52 amplifies the downlink signal superimposed on the carrier wave to a desired level by a high power amplifier (not shown), and transmits the downlink signal to the antenna 51.

Further, the wireless processing unit 52 amplifies the uplink signal received from the antenna 51 with a low noise amplifier (not shown). The radio processing unit 52 converts the frequency of the uplink signal from the radio frequency to the baseband frequency by multiplying the amplified uplink signal by a periodic signal having an intermediate frequency. Then, the wireless processing unit 52 performs analog/digital conversion on the uplink signal having the baseband frequency, and then passes it to the control unit 55.

The wired interface unit 53 has a communication interface circuit for connecting the base station 41 to an upper node device (not shown) and another base station. Then, the wired interface unit 53 analyzes the signal received from the upper node device according to the S1 interface, and extracts the downlink signal and the control signal included in the signal. Furthermore, the wired interface unit 53 analyzes a signal received from another base station according to the X2 interface and extracts a control signal included in the signal. Then, the wired interface unit 53 passes the extracted downlink signal and control signal to the control unit 55.

On the other hand, the wired interface unit 53 converts the uplink signal received from the control unit 55 into a signal in a format according to the S1 interface, and then outputs the signal to the upper node device. The wired interface unit 53 also converts a control signal transmitted to another base station into a format conforming to the X2 interface. Then, the wired interface unit 53 outputs the control signal to another base station.

The storage unit 54 has, for example, a rewritable nonvolatile semiconductor memory or a volatile semiconductor memory. The storage unit 54 stores various kinds of information for communicating with the mobile station 42, various kinds of information transmitted or received by the base station 41, and various programs operated by the base station 41. Further, the storage unit 54 stores various kinds of information used for determining whether or not the retransmission control is applicable.

The control unit 55 has, for example, one or a plurality of processors and their peripheral circuits. Then, the control unit 55 modulates and multiplexes the downlink signal according to the modulation and multiplexing method adopted in the communication standard with which the wireless communication system 2 complies. Then, the control unit 55 passes the modulated and multiplexed downlink signal to the wireless processing unit 52. For example, the control unit 55 modulates and multiplexes the downlink signal according to Orthogonal frequency-division multiple access (OFDMA).

On the other hand, the control unit 55 separates the uplink signal received from the wireless processing unit 52 according to the modulation and multiplexing method adopted in the communication standard with which the wireless communication system 2 complies, and demodulates the separated received signals. For example, the control unit 55 separates and demodulates the uplink signal according to Single-Carrier Frequency Division Multiple Access (SC-FDMA) or a multiplexing method according to another FDMA method. Then, the control unit 55 outputs the demodulated uplink signal to the wired interface unit 53. Further, the control unit 55 extracts various signals referred to by the base station 41, for example, control information relating to call control, or parameters indicating the communication state or communication amount from the mobile station 42 from the demodulated uplink signal. ..

Further, the control unit 55 executes various processes for executing wireless communication such as transmission power control and call control. Further, the control unit 55 executes various kinds of processing for determining whether to apply the retransmission control. Therefore, the control unit 55, similar to the control unit 24 of the communication device 11 according to the first embodiment shown in FIG. 4, has a retransmission control unit 241, a notification unit 242, and a retransmission control execution unit regarding retransmission control. 243.

The retransmission control unit 241 determines whether to apply the retransmission control, for example, according to the communication state or the communication amount of the wireless communication between the base station 41 and the mobile station 42. HARQ is used as the retransmission control, for example.

For example, the retransmission control unit 241 may determine not to apply the retransmission control when the value of the parameter indicating the radio quality of the downlink signal or the uplink signal satisfies a predetermined quality standard. The parameter indicating the wireless quality is an example of the parameter indicating the communication state of the wireless communication between the base station 41 and the mobile station 42. On the other hand, the retransmission control unit 241 may determine to apply the retransmission control when the value of the parameter indicating the wireless quality does not satisfy the predetermined quality standard. For example, Channel Quality Indicator (CQI) is used as a parameter indicating wireless quality. In this case, the retransmission control unit 241 compares the CQI included in the measurement report received by the base station 41 from the mobile station 42 with a predetermined threshold. Then, the retransmission control unit 241 may determine not to apply the retransmission control when the CQI is equal to or more than the predetermined threshold, and may determine to apply the retransmission control when the CQI is less than the predetermined threshold.

Alternatively, the measurement value of the Sounding Reference Signal (SRS) transmitted from the mobile station 42 may be used as the parameter indicating the radio quality. Also in this case, the retransmission control unit 241 compares the measured value with the threshold value. Then, the retransmission control unit 241 determines not to apply the retransmission control when the measured value is equal to or more than the predetermined threshold value, and determines to apply the retransmission control when the measured value is less than the predetermined threshold value. Good.

Alternatively, the retransmission control unit 241 determines not to apply the retransmission control when the relative movement speed of the mobile station 42 with respect to the base station 41 is equal to or lower than a predetermined threshold, while the relative movement speed is determined to be the predetermined threshold. It may be decided to apply the retransmission control when it is faster than the above. The relative moving speed of the mobile station 42 with respect to the base station 41 is another example of the parameter indicating the communication state of wireless communication between the base station 41 and the mobile station 42. In this case, the retransmission control unit 241 may use, for example, the moving speed of the mobile station 42, which is estimated by measuring the Doppler frequency and is notified from the mobile station 42, to determine whether to apply the retransmission control. Alternatively, the retransmission control unit 241 may calculate the moving speed of the mobile station 42 based on the time change of the position information of the mobile station 42.

Alternatively, when the base station 41 can set a plurality of communicable ranges, when the mobile station 42 moves from any communicable range to another communicable range within the latest predetermined period, the retransmission control unit 241. May decide to apply retransmission control. On the other hand, when the mobile station 42 remains within one of the communicable ranges within the latest predetermined period, the retransmission control unit 241 may determine not to apply the retransmission control. Whether or not the mobile station 42 has moved between the communicable ranges is another example of the parameter indicating the communication state of the wireless communication between the base station 41 and the mobile station 42. The communicable range can be, for example, a cell or a beam.

Alternatively, the retransmission control unit 241 decides not to apply the retransmission control when the size of the Transport Block is equal to or smaller than a predetermined threshold, while applying the retransmission control when the size of the Transport Block is larger than the predetermined threshold. Then you may decide. The size of the Transport Block is an example of the parameter indicating the communication amount.

Furthermore, the retransmission control unit 241 may determine whether to apply the retransmission control, for example, based on the combination of the communication state or the communication amount. For example, the retransmission control unit 241 determines to apply the retransmission control when the condition for applying the retransmission control is satisfied with respect to any of the above examples of some parameters, and in other cases, You may decide not to apply retransmission control.

The retransmission control unit 241 notifies the notification unit 242 and the retransmission control execution unit 243 of information indicating whether or not retransmission control is applicable.

The notification unit 242 generates a control signal including information indicating the applicability of the retransmission control each time the retransmission control unit 241 determines the applicability of the retransmission control, or at regular intervals. Then, the notification unit 242 transmits the control signal to the mobile station 42 via the wireless processing unit 52 and the antenna 51. In addition, the notification unit 242 can use the control signal as a signal transmitted via a physical downlink control channel (PDCCH). Alternatively, the notification unit 242 can use the control signal as a MAC control element (MAC CE) signal or a Radio Resource Control (RRC) signal.

The retransmission control execution unit 243 executes the retransmission control, for example, according to the operation flowchart shown in FIG. 5, similarly to the communication device 11 in the first embodiment. That is, when the retransmission control is applied, the retransmission control execution unit 243 performs the error detection process according to the error detection code added to the uplink signal according to the application of the retransmission control adopted in the wireless communication system 2. Perform on uplink signals. Thereby, the retransmission control execution unit 243 determines whether or not the data included in the uplink signal is normally reproduced. For example, the retransmission control execution unit 243 determines whether the transport block is normally reproduced, based on the CRC code attached to the transport block included in the uplink signal. Then, for example, when the data included in the uplink signal is normally reproduced, the retransmission control execution unit 243 generates an Ack signal and transmits the Ack signal to the mobile station 42 via the wireless processing unit 52 and the antenna 51. To do. On the other hand, when the data included in the uplink signal is not normally reproduced, the retransmission control execution unit 243 generates a Nack signal and transmits the Nack signal to the mobile station 42 via the wireless processing unit 52 and the antenna 51. Also, the retransmission control execution unit 243 uses the data retransmitted from the mobile station 42 to reproduce the data included in the original uplink signal.

On the other hand, when the retransmission control is not applied, the retransmission control execution unit 243 generates a response signal such as Ack/Nack regardless of whether the data included in the radio signal received from the mobile station 42 is normally reproduced. do not do.

FIG. 10 is a schematic configuration diagram of the mobile station 42. The mobile station 42 has an antenna 61, a wireless processing unit 62, a storage unit 63, and a control unit 64. Further, the mobile station 42 may include one or more of a user interface (not shown) such as a touch panel, a microphone (not shown), a speaker (not shown), and a camera (not shown). .. Furthermore, the mobile station 42 may have a Global Positioning System (GPS) receiver (not shown) for measuring the position of the mobile station 42. The wireless processing unit 62, the storage unit 63, and the control unit 64 are formed as separate circuits. Alternatively, each of these units may be implemented in the mobile station 42 as one or a plurality of integrated circuits in which circuits corresponding to the respective units are integrated.

The antenna 61 transmits the uplink signal transmitted via the wireless processing unit 62 as a wireless signal. Further, the antenna 61 receives a radio signal from the base station 41, converts the radio signal into an electric signal into a downlink signal, and transmits the downlink signal to the radio processing unit 62. Note that the antenna 61 may have a transmitting antenna and a receiving antenna separately.

The wireless processing unit 62 converts the uplink signal received from the control unit 64 into an analog signal and then superimposes it on a carrier wave having a wireless frequency designated by the control unit 64. Then, the wireless processing unit 62 amplifies the uplink signal superimposed on the carrier wave to a desired level by a high power amplifier (not shown), and transmits the uplink signal to the antenna 61.

The wireless processing unit 62 also amplifies the downlink signal received from the antenna 61 with a low noise amplifier (not shown). The radio processing unit 62 converts the frequency of the downlink signal from the radio frequency to the baseband frequency by multiplying the amplified downlink signal by a periodic signal having an intermediate frequency. Then, the wireless processing unit 62 performs analog/digital conversion on the downlink signal having the baseband frequency, and then passes it to the control unit 64.

The storage unit 63 has, for example, a rewritable nonvolatile semiconductor memory or a volatile semiconductor memory. The storage unit 63 stores various kinds of information for communicating with the base station 41, various kinds of information transmitted or received by the mobile station 42, and various programs operated by the mobile station 42. Further, the storage unit 63 stores various kinds of information used for executing the retransmission control. Furthermore, when the retransmission control is applied, the storage unit 63 stores the once transmitted uplink signal for a certain period according to the retransmission control adopted by the wireless communication system 2, for example, HARQ.

The control unit 64 has, for example, one or a plurality of processors and their peripheral circuits. Then, the control unit 64 modulates and multiplexes the uplink signal according to the modulation and multiplexing method adopted in the communication standard with which the wireless communication system 2 complies. Then, the control unit 64 passes the modulated and multiplexed uplink signal to the wireless processing unit 62. For example, the control unit 64 modulates and multiplexes the uplink signal according to SC-FDMA or a multiplexing method according to another FDMA method.

On the other hand, the control unit 64 separates the downlink signal received from the wireless processing unit 62 according to the modulation and multiplexing scheme adopted by the communication standard with which the wireless communication system 2 complies, and demodulates the separated received signals, respectively. For example, the control unit 64 separates and demodulates the downlink signal according to OFDMA. Then, the control unit 64 extracts various control information or data included in the demodulated received signal. Then, the control unit 64 executes processing according to the extracted control information or data. For example, when the downlink signal includes an audio signal, the control unit 64 reproduces the audio signal via the speaker. When the downlink signal includes a video signal, the control unit 64 reproduces the video signal via the touch panel.

Further, the control unit 64 executes various processes such as a connection request process for executing wireless communication with the base station 41.

The control unit 64 also executes various processes for executing retransmission control. The control unit 64, for example, the CQI, the moving speed of the mobile station 42, or the current position of the mobile station 42, an uplink signal including information used to determine the applicability of retransmission control, at regular intervals, Alternatively, it is generated at a predetermined timing. The predetermined timing may be, for example, a handover or a connection request. Then, the control unit 64 transmits the uplink signal to the base station 41 via the wireless processing unit 62 and the antenna 61.

In addition, every time the control unit 64 receives a control signal including information indicating the applicability of retransmission control from the base station 41, the control unit 64 refers to the information and controls the application of retransmission control. For example, the control unit 64 may control the application of the retransmission control, for example, according to the operation flowchart illustrated in FIG. 7, similarly to the communication device 12 according to the second embodiment.

That is, if the received control signal includes information indicating that retransmission control is applied, the control unit 64 applies retransmission control. In this case, the control unit 64 adds an error detection code related to retransmission control to the uplink signal. The control unit 64 can use a CRC code as the error detection code, for example. In addition, the control unit 64 retransmits the transmitted uplink signal until a signal (for example, an Ack signal) indicating that the data transmitted from the base station 41 is normally reproduced is notified or until a certain period of time elapses. It is stored in the storage unit 63 for this purpose. Then, when the control unit 64 receives a signal requesting retransmission from the base station 41 (for example, a Nack signal), the control unit 64 generates an uplink signal for retransmission including some or all of the data included in the uplink signal. .. The control unit 64 transmits the generated uplink signal to the base station 41 via the wireless processing unit 62 and the antenna 61.

On the other hand, if the received control signal includes information indicating that retransmission control is not applied, the control unit 64 does not apply retransmission control. In this case, the control unit 64 does not attach the error detection code related to the retransmission control to the data included in the uplink signal. Further, in this case, the control unit 64 may discard the data included in the uplink signal transmitted to the base station 41 without storing it in the storage unit 63.

FIG. 11A is a diagram showing an example of the structure of data transmitted in an uplink signal when retransmission control is applied, and FIG. 11B is an uplink when retransmission control is not applied. It is a figure which shows an example of the structure of the data transmitted by a signal.

As shown in FIG. 11(A), a CRC code 1102 of a predetermined length (for example, 24 bit length) is attached to each code block 1101 included in the uplink signal in the physical (PHY) layer. Then, the base station 41 uses the CRC code 1102 to determine whether or not each code block 1101 is normally reproduced. Further, when retransmission control is applied, in the Media access control (MAC) layer, one or more code blocks 1101 to a transport block 1103 and a predetermined length for retransmission control, for example, ARQ/Nack determination of HARQ ( For example, a 24-bit length CRC code 1104 is obtained. Then, based on the CRC code 1104, it is determined whether the transport block 1103 is reproduced normally. Then, an RLC Protocol Data Unit (RLC PDU) 1105 is obtained from the transport block 1103 in the Radio Link Control (RLC) layer. Then, the RLC PDU 1105 is divided into a plurality of RLC SDUs 1106. Each RLC SDU 1106 is, for example, IP packetized and transmitted from the base station 41 to the upper node device.

On the other hand, as shown in FIG. 11B, even when the retransmission control is not applied, each of the physical layer uses the CRC code 1112 of a predetermined length (for example, 24 bit length) attached to each code block 1111. It is determined whether the code block 1111 is reproduced normally. Then, in the MAC layer, a transport block 1113 is obtained from one or more code blocks 1111. However, when retransmission control is not applied, the transport block 1113 is not provided with a CRC code for retransmission control. Then, in the RLC layer, the RLC PDU 1115 is obtained from the transport block 1113. Then, the RLC PDU 1115 is divided into a plurality of RLC SDUs 1116. Each RLC SDU 1116 is, for example, IP packetized and transmitted from the base station 41 to the upper node device.

As another example, as shown in FIG. 11(C), a layer for executing retransmission control-related processing on data 1120 included in a signal transmitted by an uplink signal is used for retransmission control. Whether or not the error detection code 1121 is added may be switched. That is, when the retransmission control is applied, the error detection code 1121 is attached to the data 1120, while when the retransmission control is not applied, the error detection code 1121 may be omitted. The error detection code 1121 may be a CRC code or another error detection code.

As described above, in the wireless communication system according to the second embodiment, the base station determines the applicability of retransmission control and notifies the mobile station of the applicability. Then, the mobile station controls the application of retransmission control according to the notification. Therefore, this wireless communication system can dynamically switch whether or not to apply the retransmission control, so that it is possible to suppress a decrease in communication efficiency due to the retransmission control when it is not necessary to apply the retransmission control. As a result, this wireless communication system can improve communication efficiency.

According to the modification, the mobile station may determine whether to apply the retransmission control, generate an uplink control signal including information indicating whether the retransmission control is applicable, and transmit the uplink control signal to the base station. Then, the base station may control the application of the retransmission control according to the information included in the control signal and indicating whether the retransmission control is applicable.

In this case, for example, even if the control unit 64 of the mobile station 42 shown in FIG. 10 executes the processes of the retransmission control unit 241, the notification unit 242, and the retransmission control execution unit 243 shown in FIG. Good. In this case, the control unit 64 may determine whether to apply the retransmission control, for example, according to the type of data transmitted from the base station 41 to the mobile station 42. For example, the control unit 64 may specify the type of data transmitted from the base station 41 to the mobile station 42 based on the application program or the like being executed by the control unit 64. Then, the control unit 64 determines that the retransmission control is not applied when the data transmitted from the base station 41 to the mobile station 42 is data that requires real-time processing, such as streaming data and voice call data. May be. In addition, the control unit 64 applies the retransmission control even when the data transmitted from the base station 41 to the mobile station 42 is data transmitted at a constant cycle, such as Internet of Things (IoT) data. You may decide not to. On the other hand, when the data transmitted from the base station 41 to the mobile station 42 is data required to be reproduced normally in the mobile station 42, for example, some computer program, the control unit 64 controls the retransmission control. May be applied.
Then, the control unit 64 may generate an uplink control signal including information indicating whether or not retransmission control is applicable, and transmit the control signal to the base station 41 via the wireless processing unit 62 and the antenna 61.

On the other hand, like the control unit 64 of the mobile station 42, the control unit 55 of the base station 41 may control the application of the retransmission control based on the uplink control signal received from the mobile station 42.

Further, according to another modification, even when retransmission control is not applied, the base station 41 or the mobile station 42 attaches an error detection code related to retransmission control to the data included in the downlink signal or the uplink signal. You may. Alternatively, the base station 41 or the mobile station 42 may differ the error detection code added to the data when the retransmission control is applied and the error detection code added to the data when the retransmission control is not applied. Good. For example, rather than the error correction capability of the error detection code (error correction code) added to the data when the retransmission control is applied, the error detection code (error correction code) added to the data when the retransmission control is not applied The error correction capability of may be higher.

According to yet another modification, one of the base station 41 and the mobile station 42 sends a control signal including information indicating whether to apply an error detection code related to retransmission control to the base station 41 and the mobile station. It may be transmitted to the other of the stations 42. Note that this control signal can be, for example, a signal transmitted via the PDCCH, a MAC CE signal, or an RRC signal, as in the above embodiment. Further, the criterion for determining whether to apply the error detection code related to the retransmission control can be the same as the criterion for determining whether to apply the retransmission control, for example. Then, the base station 41 or the mobile station 42 that receives the control signal may control the application of the error detection code related to the retransmission control according to the control signal. For example, when the control signal includes information indicating that the error detection code related to the retransmission control is not added, the base station 41 or the mobile station 42 that has received the control signal changes the data included in the transmission signal. , No error detection code related to retransmission control is attached. In this case, the mobile station 42 or the base station 41 that has received the transmission signal detects an error that is not associated with retransmission control, such as the CRC code attached to the code block shown in FIG. The code may be used to execute the retransmission control. On the other hand, when the control signal includes the information indicating that the error detection code related to the retransmission control is added, the base station 41 or the mobile station 42 that has received the control signal retransmits the data included in the transmission signal. An error detection code related to control is attached. As a result, the wireless communication system can dynamically switch whether or not to attach the error detection code related to the retransmission control to the data to be transmitted. This wireless communication system can reduce the communication amount by the bit amount corresponding to the error detection code when it is not necessary to additionally attach the error detection code related to the retransmission control. As a result, this wireless communication system can improve communication efficiency.

The control signal may include information indicating whether or not to apply the error detection code related to the retransmission control, together with information indicating whether or not the retransmission control is appropriate. Alternatively, one of the base station 41 and the mobile station 42 includes a control signal including information indicating whether to apply an error detection code related to retransmission control, and a control signal including information indicating appropriateness of retransmission control. Either one of them may be transmitted to the other of the base station 41 and the mobile station 42.

It should be noted that the above-described respective embodiments or modified examples may be combined. For example, the communication device 11 in the first embodiment may be the base station 41 or the mobile station 42 in the second embodiment or the modification. Similarly, the communication device 12 in the first embodiment may be the base station 41 or the mobile station 42 in the second embodiment or the modification.

All examples and specific terms given herein are intended for instructional purposes to help the reader understand the invention and the concepts contributed by the inventor to the promotion of the art. It is to be construed as not limiting to the constitution of any example herein, such specific examples and conditions relating to indicating the superiority and inferiority of the present invention. While the embodiments of the invention have been described in detail, it should be understood that various changes, substitutions and modifications can be made thereto without departing from the spirit and scope of the invention.

1, 2 Wireless communication system 11, 12 Communication device 41 Base station 42 Mobile station 21, 31, 51, 61 Antenna 22, 32, 52, 62 Wireless processing unit 23, 33, 54, 63 Storage unit 24, 34, 55, 64 control unit 53 wired interface unit 241 retransmission control unit 242 notification unit 243 retransmission control execution unit

Claims (9)

A communication device,
A wireless processing unit that transmits or receives a wireless signal,
A control unit that controls the application of the retransmission control according to information indicating whether or not to apply the retransmission control, which is included in a wireless signal received from another communication device via the wireless processing unit. ,
The control unit detects an error for each data block in the first layer and the second layer set when transmitting a radio signal to the other communication device, depending on whether or not to apply the retransmission control. A communication device for controlling whether or not a code is given to form a radio signal for transmitting the data block. When the retransmission control is not applied, the control unit adds the error detection code to the data block of the first layer included in the radio signal transmitted to the other communication device, and the data block of the second layer. The communication device according to claim 1, wherein the error detection code is not attached to the. When applying the retransmission control, the control unit adds the error detection code to the data block of the first layer and the data block of the second layer included in the radio signal transmitted to the other communication device. The communication device according to claim 2, wherein: A communication system having a first communication device and a second communication device,
The first communication device transmits a radio signal including information indicating whether to apply retransmission control to the second communication device,
The second communication device controls application of the retransmission control according to the information,
The second communication device is a data block in a first layer and a second layer set when transmitting a radio signal to the first communication device according to whether to apply the retransmission control. A communication system for controlling whether or not to add an error detection code for each and forming a radio signal for transmitting the data block. When not applying the retransmission control, the second communication device adds the error detection code to a data block of the first layer included in a radio signal transmitted to the first communication device, and The communication system according to claim 4, wherein the error detection code is not added to a data block of a layer. When applying the retransmission control, the second communication device detects the error in the data block of the first layer and the data block of the second layer included in the radio signal transmitted to the first communication device. The communication system according to claim 5, wherein a code is added. Included in the radio signal received from the other communication device, according to the information indicating whether to apply the retransmission control, controlling the application of the retransmission control,
Whether an error detection code is added to each data block in the first layer and the second layer set when transmitting a radio signal to the other radio device depending on whether or not the retransmission control is applied A communication method comprising controlling whether or not to form a radio signal for transmitting the data block. When the retransmission control is not applied, the error detection code is added to the data block of the first layer included in the radio signal transmitted to the other communication device, and the error detection code is added to the data block of the second layer. 8. The communication method according to claim 7, wherein is not attached. When the retransmission control is applied, the error detection code is added to the data block of the first layer and the data block of the second layer included in the radio signal transmitted to the other communication device. The communication method according to claim 8.

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