JP6756673B2 - Wireless terminals, wireless base stations, wireless communication systems, and wireless communication methods - Google Patents

Description

The present invention relates to wireless terminals, wireless base stations, wireless communication systems, and wireless communication methods.

In recent years, in wireless communication systems such as mobile phone systems (cellular systems), discussions have been held on next-generation wireless communication technologies in order to further increase the speed and capacity of wireless communication. For example, 3GPP (3rd Generation Partnership Project), a standardization organization, proposes a communication standard called LTE (Long Term Evolution) and a communication standard called LTE-A (LTE-Advanced) based on LTE wireless communication technology. Has been done.

The latest communication standard completed in 3GPP is Release 10 for LTE-A, which is a major extension of LTE-compatible Releases 8 and 9. Currently, discussions are underway toward the completion of Release 11, which is an extension of Release 10. Hereinafter, unless otherwise specified, "LTE" shall include LTE and LTE-A, as well as other wireless communication systems that extend them.

Release 11 of 3GPP includes various technologies, and one of them is MTC (Machine Type Communication). MTC corresponds to so-called M2M (Machine To Machine) communication in the LTE system, and refers to a communication form in which machines (Machines) exchange information without human intervention. Specific application examples of MTC include monitoring of meters for electricity, gas, water, etc., crime prevention monitoring, monitoring of various devices, sensor networks, and the like. It is also assumed that, for example, electrical equipment in the home will cooperate with each other by supporting MTC. Discussions on MTC in 3GPP have just begun, but since MTC is considered to have an extremely wide range of applications, it is expected that lively discussions will continue as a promising technology in 3GPP.

Special Table 2010-519793 Japanese Unexamined Patent Publication No. 2012-80415

3GPP TS46.211 V11.0.0 (2012-09) 3GPP TS46.212 V11.0.0 (2012-09) 3GPP TS46.213 V11.0.0 (2012-09) 3GPP TR36.321 V11.0.0 (2012-09) 3GPP TR36.331 V11.0.0 (2012-09)

Various devices corresponding to MTC are generally called MTC devices, but it is considered that MTC devices have some different properties as compared with general mobile phone terminals (so-called cellular terminals). For MTC devices, considering these differences in properties, consider changing (extending or simplifying, etc.) various controls and processes applied to general mobile phone terminals as necessary. There is a need to. This is because if various controls and processes applied to a general mobile phone terminal are applied to the MTC device as they are, adverse effects may occur or functional redundancy may occur.

However, discussions on MTC devices have only just begun, and the reality is that there are countless studies on various controls and processes based on the nature of MTC. In particular, there is an aspect that little progress has been made on the scheduling method based on the nature of MTC. Although some scheduling methods have already been specified in the current LTE system, these are not always sufficiently efficient in view of changes in the usage patterns of mobile phone terminals such as MTC devices in the present and future. there is a possibility.

Although the explanation leading to the above problem has been given based on the MTC device in the LTE system, this problem can be extended to general mobile phone terminals. That is, although some scheduling methods have already been defined in the current LTE system, these may not always be sufficiently efficient in view of changes in the usage patterns of mobile phone terminals now and in the future.

The disclosed technology has been made in view of the above, and in one aspect, wireless terminals, wireless base stations, which can perform efficient scheduling based on changes in the usage patterns of mobile phone terminals now and in the future. It is an object of the present invention to provide a wireless communication system and a wireless communication method.

In one embodiment, a receiver for receiving the first information including information on the communication distance in the communication of Ru place in communication intervals comprising a plurality of sections from the radio base station, based on the first information, the and a communication unit for performing pre-Symbol communications and a radio base station, the first information, for changing the predetermined number of sections performing pre Symbol communications among the plurality of sections for each of the communication section Includes second information.

One aspect of the wireless terminals, wireless base stations, wireless communication systems, and wireless communication methods disclosed in this case has the effect of being able to perform efficient scheduling in light of changes in the current and future usage patterns of mobile phone terminals. Play.

FIG. 1 is a diagram showing an example of an upstream semi-persistent scheduling processing sequence. FIG. 2 is an enlarged view of a part of an example of the processing sequence of the upstream semi-persistent scheduling. FIG. 3 is a diagram showing an example of a processing sequence of downlink semi-persistent scheduling. FIG. 4 is an enlarged view of a part of an example of the processing sequence of the downlink semi-persistent scheduling. FIG. 5 is a diagram showing an example of a processing sequence of the wireless communication system according to the first embodiment. FIG. 6 is an enlarged view of a part of an example of the processing sequence of the wireless communication system according to the first embodiment. FIG. 7 is a diagram showing an example of a processing sequence of the wireless communication system according to the second embodiment. FIG. 8 is a diagram showing an example of an RRC signal in a conventional LTE system. FIG. 9 is a diagram showing an example of an RRC signal in the wireless communication system according to the second embodiment. 10A to 10B are diagrams showing an example of DCI in the wireless communication system according to the second embodiment. FIG. 11 is an enlarged view of a part of an example of the processing sequence of the wireless communication system according to the second embodiment. FIG. 12 is a diagram showing an example of a processing sequence of the wireless communication system according to the third embodiment (no free resource allocation in the upstream case). FIG. 13 is a diagram showing an example of a processing sequence of the wireless communication system according to the third embodiment (with free resource allocation in the upstream case). FIG. 14 is a diagram showing an example of a processing sequence of the wireless communication system according to the third embodiment (with free resource allocation in the case of downlink). FIG. 15 is a diagram showing an example of a processing sequence of the wireless communication system according to the fourth embodiment. FIG. 16 is a diagram showing an example of a processing sequence of the wireless communication system according to the fifth embodiment. FIG. 17 is a diagram showing another example of the processing sequence of the wireless communication system according to the fifth embodiment. FIG. 18 is a diagram showing a configuration of a wireless communication system according to each embodiment. FIG. 19 is a functional block diagram showing a configuration of a radio base station according to each embodiment. FIG. 20 is a functional block diagram showing a configuration of a wireless terminal according to each embodiment. FIG. 21 is a diagram showing a hardware configuration of a radio base station according to each embodiment. FIG. 22 is a diagram showing a hardware configuration of a wireless terminal according to each embodiment.

Hereinafter, embodiments of the disclosed wireless terminal, wireless base station, wireless communication system, and wireless communication method will be described with reference to the drawings. Although it will be described as a separate embodiment for convenience, it goes without saying that by combining the respective embodiments, the effect of the combination can be obtained and the usefulness can be further enhanced.

[Location of the problem]
First, before explaining each embodiment, the location of a problem in the prior art will be described. It should be noted that this problem was newly discovered as a result of the inventor's detailed examination of the prior art, and was not known in the past.

As mentioned above, MTC devices are considered to have some different properties compared to common mobile phone terminals (so-called cellular terminals). For example, one of the unique properties of MTC devices is that most MTC devices do not move (or are extremely limited even if they move). This is because a general mobile phone terminal may move at high speed (such as when moving in a high-speed vehicle), but it is difficult to assume such a case for MTC devices such as electricity meters and security sensors.

Since MTC devices rarely move, it is considered that MTC devices hardly require the mobility required for general mobile phone terminals. For example, in an MTC device, the handover function may not be necessary. Here, we focus on scheduling for MTC devices. Here, scheduling means that a wireless base station specifies a wireless resource, a modulation method, a coding method, etc. used for transmission / reception to a wireless terminal (including an MTC device).

Given the property of almost no movement, it is considered that there is little significance in implementing so-called dynamic scheduling in MTC devices. Here, the dynamic scheduling is to perform dynamic scheduling each time transmission / reception is performed. In LTE dynamic scheduling, Adaptive Modulation and Coding (AMC) is adopted as an elemental technology. Adaptive modulation coding is a technology that enhances communication efficiency by sequentially selecting the modulation method and coding method used for data transmission and reception according to the wireless quality, and in particular, wireless quality such as wireless terminals moving at high speed. It is effective when the value is liable to change. However, as mentioned above, the MTC device does not move much, and the radio quality is considered to be almost constant. Therefore, it is considered that the need to perform adaptive modulation coding is less than that of a general mobile phone terminal. Be done.

On the contrary, when dynamic scheduling is performed on MTC devices, there is a concern that a large amount of signaling (control signal) will be generated. In particular, there is a problem in the case of performing uplink data transmission (data transmission from a wireless terminal to a wireless base station) based on dynamic scheduling. When downlink data is transmitted (data transmission from a wireless base station to a wireless terminal) based on dynamic scheduling, the wireless base station uses control information to indicate the downlink data and the wireless resource that maps the downlink data. Since it is only necessary to send a certain DCI (Downlink Control Information) to the wireless terminal together, the amount of signaling does not matter much. On the other hand, in uplink data transmission, a wireless base station cannot allocate an appropriate amount of wireless resources without knowing the existence and data size of uplink data that the wireless terminal wants to transmit, so compared to downlink data transmission. The processing becomes complicated.

Specifically, in the transmission of uplink data based on dynamic scheduling, two round-trip control signals are transmitted and received between the wireless terminal and the wireless base station each time the data is transmitted. Specifically, first, the wireless terminal transmits SR (Scheduling Request), which is a control signal requesting transmission of uplink data, to the wireless base station. The radio base station then sends an Initial UL Grant to the radio terminal that allocates a predetermined amount of uplink radio resources. Then, the wireless terminal transmits a BSR (Buffer Status Report) indicating the data size of the uplink data to the wireless base station based on a predetermined amount of uplink radio resources allocated by the Initial UL Grant. Finally, the radio base station determines the radio resource to be allocated to the radio terminal based on the received BSR, and transmits a UL Grant to the radio terminal indicating that the radio terminal is allowed to transmit uplink based on the radio resource. ..

As described above, a large amount of signaling is required especially for upstream data transmission based on dynamic scheduling. Here, it is assumed that the number of MTC devices will be larger than that of general mobile phone terminals. Therefore, if dynamic scheduling is performed on the MTC device, there is a concern that the amount of signaling in the system will be enormous. As the amount of signaling increases, the radio resources that can be used to send and receive data are compressed, and should be avoided from the viewpoint of efficient use of radio resources. In addition, MTC devices are often required to save power, but as the amount of signaling increases, the power consumption required for the processing also increases, which is considered undesirable.

On the other hand, in LTE, a scheduling method called Semi-Persistent Scheduling (SPS) is defined for the dynamic scheduling described above. SPS does not allocate radio resources in a rotating manner like dynamic scheduling, but allocates radio resources semi-persistently.

FIG. 1 shows an example of the upstream SPS processing sequence in LTE. Here, the uplink (wireless communication from the wireless terminal 20 to the wireless base station 10) SPS will be described, but in LTE, the SPS is also applied to the downlink (wireless communication from the wireless base station 10 to the wireless terminal 20). be able to.

First, in S101 of FIG. 1, the radio base station 10 notifies the radio terminal 20 of basic parameters in the SPS. The notification of S101 is transmitted and received via the Physical Downlink Shared CHannel (PDSCH) by the RRC signal which is L3 (Layer 3) signaling. The SPS parameters notified by the RRC signal of S101 include, for example, the SPS communication interval and the like. The radio base station 10 can set the SPS communication interval in units of subframes (1 msec). The RRC signal of S101 only notifies the basic parameters of SPS, and transmission / reception based on SPS is not started at the timing based on this RRC signal.

Next, in S102, the radio base station 10 transmits a control signal for activating the SPS to the radio terminal 20. The control signal of S102 is transmitted and received via a physical downlink control channel (PDCCH: Physical Downlink Control CHannel) by DCI (Downlink Control Information) which is L1 (Layer 1) signaling. The control signal of S102 activates the SPS whose basic parameters are set by the RRC signal of S101, and transmission / reception based on the SPS is started. The DCI corresponding to the control signal of S102 includes the parameters necessary for executing the SPS. The parameters included in the DCI are the specification of the radio resource corresponding to the Physical Uplink Shared CHannel in each subframe in which the SPS-based transmission is performed, and the modulation coding method (MCS) applied to the SPS-based transmission. : Modulation and Coding) is included.

Then, from S103 to S109, the wireless terminal 20 performs transmission based on SPS via PUSCH without using special signaling. The first transmission based on the SPS, S103, is performed four subframes after the subframes in which DCI is transmitted and received in S102. After that, in the subframe for each communication interval notified by the RRC signal of S101, the wireless terminal 20 transmits to the wireless base station 10 based on SPS via PUSCH.

FIG. 2 shows an enlarged view corresponding to S102 to S105 of FIG. FIG. 2 illustrates a case where the communication interval of SPS is 20 subframes as an example. As shown in FIG. 2, as described above, the first transmission based on the SPS, S103, is performed four subframes after the subframe in which DCI is received in S102. After that, the wireless terminal 20 transmits to the wireless base station 10 based on SPS in each 1 subframe every 20 subframes which is the communication interval.

Returning to FIG. 1, in S110, the radio base station 10 transmits a control signal for releasing the SPS to the radio terminal 20. The control signal of S110 is transmitted and received by DCI via PDSCH as in S102. The control signal of S110 releases the SPS activated in S103, and transmission / reception based on the SPS is terminated. As a result, transmission based on SPS is not performed after S106. However, if the radio base station 10 activates the SPS again after S106, the radio terminal 20 can restart the transmission based on the SPS.

As an example in FIG. 1, the radio base station 10 opens the SPS after transmission based on the SPS is performed 7 times or more (including omission in the figure), but the radio base station 10 has an arbitrary timing. You can release the SPS with. For example, the wireless base station 10 can release the SPS at the timing when the application using the SPS (call by VoIP, etc.) is completed.

On the other hand, FIG. 3 shows an example of the downlink SPS processing sequence in LTE. Further, FIG. 4 shows an enlarged view corresponding to S202 to S205 of FIG. In the uplink SPS shown in FIGS. 1 and 2, each transmission (S103 to S109) was performed via PUSCH, whereas in the downlink SPS shown in FIGS. 3 to 4, each transmission (S203 to S209) was performed. Is different in that it is done via PDSCH.

According to the SPS described with reference to FIGS. 1 to 4, it is not necessary to perform signaling for allocating radio resources each time data is transmitted as in dynamic scheduling. For example, if the transmission as shown in S103 to S109 of FIG. 1 is performed by dynamic scheduling, signaling for resource allocation is required for each transmission of S103 to S109. On the other hand, in the SPS shown in FIG. 1, signaling for resource allocation is not required for each transmission of S103 to S109. The only signaling required in the SPS shown in FIG. 1 is S101 and S102 to start the SPS-based transmission and S110 to end the SPS-based transmission. Therefore, according to SPS, it is possible to suppress the amount of signaling as compared with dynamic scheduling. It is considered that the effect of suppressing the amount of signaling increases as the number of times the SPS is transmitted (or the execution period of the SPS becomes longer).

On the other hand, SPS also has disadvantages in comparison with dynamic scheduling. One of the disadvantages of SPS is that it is more vulnerable to changes in the wireless environment than dynamic scheduling. This disadvantage is due to the fact that the adaptive modulation coding described above cannot be applied to SPS. Since adaptive modulation coding is realized by specifying the MCS according to the wireless environment for each communication, signaling for notifying the MCS is required for each communication. However, since SPS omits signaling every time it communicates, it is inherently impossible to apply adaptive modulation coding. Therefore, in SPS, the MCS specified at the time of activation (S102 in FIG. 1) is continuously used until the time of release (S110 in FIG. 1). Therefore, in SPS, it is not possible to change to MCS that is resistant to errors, for example, when the wireless environment deteriorates after activation. Therefore, SPS has the property of being vulnerable to changes in the wireless environment. If you want to change to an error-resistant MCS, you need to re-activate the SPS. Reactivation of SPS includes parameters necessary for execution of SPS, as in the case of activation of SPS. The parameters included in the DCI are the specification of the radio resource corresponding to the Physical Uplink Shared CHannel in each subframe in which the SPS-based transmission is performed, and the modulation coding method (MCS) applied to the SPS-based transmission. : Modulation and Coding) is included.

Returning to scheduling for MTC devices, MTC devices are considered to be relatively compatible with the SPS described above. First, as mentioned above, adaptive modulation coding is not applied to SPS, but it is considered to have little adverse effect on MTC devices where there is almost no change in radio quality due to movement. Further, even if the SPS is upstream, signaling is only at the beginning and the end, and unlike dynamic scheduling, signaling is not transmitted / received each time uplink data is transmitted. Therefore, the amount of signaling sent and received by the MTC device can be suppressed.

As described above, when SPS is applied to an MTC device, it is considered that the advantages of SPS can be enjoyed with almost no influence from the disadvantages of SPS. Therefore, MTC devices are compatible with SPS, and it is desirable to apply SPS to MTC devices for scheduling.

By the way, SPS has conventionally been assumed to be applied to VoIP and the like as described above. Here, since the call data based on VoIP is voice data, it is considered that the amount of data per transmission is not so large.

On the other hand, in the future, when SPS is applied to MTC devices, it is expected that data such as relatively large moving images and still images will be transmitted and received. As an example, consider applying SPS to a surveillance camera that supports MTC. The surveillance camera transmits images taken at a predetermined cycle to the server at a predetermined communication interval (for example, 80 msec) based on the SPS. In such a case, a relatively large amount of data will be transmitted and received in each transmission of SPS.

Here, when the wireless terminal 20 sends a relatively large amount of data, it is necessary to allocate a relatively large amount of wireless resources to the wireless terminal 20. In order to realize this in the conventional SPS, it is necessary to allocate a relatively large radio resource in one subframe corresponding to the transmission timing of the SPS. In this case, a relatively large radio resource is reserved semi-continuously for the specific radio terminal 20 for each subframe corresponding to the transmission timing of the SPS. However, allocating a relatively large radio resource to a specific radio terminal 20 in a future subframe deprives the flexibility of radio resource allocation in the subframe of another radio terminal 20 in advance, which is not preferable. ..

For example, when the number of wireless terminals 20 that carry out SPS increases, it is possible that a certain subframe may be compressed by the wireless resource for SPS. In such a case, if data transmission other than SPS with high priority or urgency occurs in the subframe compressed by the radio resource for SPS, it is assumed that it will be difficult to deal with it. In particular, considering that the number of wireless terminals 20 will increase due to the spread of MTC devices in the future, it is considered that the flexibility of allocation of wireless resources should be ensured as much as possible.

Further, in addition to the above circumstances, it is considered that many MTC devices have a characteristic that small-sized data is frequently generated, such as various sensor devices in a sensor network. In such an MTC device, there is a concern that the allocation of radio resources may be insufficient in the one-shot type SPS as shown in FIGS. 1 to 4. It is also possible to apply one-shot type SPS to such MTC devices on the premise that the data to be transmitted is buffered to some extent. However, the memory installed in the MTC device is often small, and so much data cannot be buffered, so it is considered that the MTC device and the one-shot type SPS are not so compatible.

Although the above description is based on the MTC device as an example, the above problem is not necessarily limited to the MTC device. It is considered that the above problem can occur, for example, in a normal mobile phone terminal used in a form similar to or similar to that of an MTC device.

Summarizing the above, it is considered that the conventional SPS was not supposed to send and receive relatively large data such as image data. Therefore, if the conventional SPS is applied as it is to a mobile phone terminal including an MTC device such as a surveillance camera, there is a possibility that the flexibility in allocating wireless resources in the future will be lost. Further, since the MTC device has a feature that small data is generated frequently, it is difficult for the conventional one-shot type SPS to handle it. As described above, this problem was newly discovered as a result of the inventor's detailed examination of the prior art, and has not been known in the past. Hereinafter, each embodiment of the present application for solving this problem will be described in order.

[First Embodiment]
In the first embodiment, the wireless base station 10 designates the wireless terminal 20 as a communication interval for communication performed at a predetermined communication interval and a communication section for performing the communication at each communication interval. In other words, the receiving unit that receives the first information including the communication interval in the communication performed at the communication interval consisting of a plurality of sections from the radio base station, and the radio base station and the communication based on the first information. The first information includes a wireless terminal 20 including a second information indicating that the communication is performed in a predetermined number of sections among the plurality of sections, a wireless communication system including the same, and the like. Corresponds to.

The premise of the wireless communication system of the first embodiment will be described. The wireless resource used by the wireless communication system of the first embodiment has at least a time component, and for convenience, the unit of the time component will be referred to as a communication section. It is assumed that the radio base station 10 and the radio terminal 20 can transmit and receive in units of communication sections in the time direction. The term "communication section" is merely an example of a term indicating a unit of a time component of a radio resource, and is referred to as a term such as a frame, a subframe, a slot, a time slot, or (simply) a section. Needless to say, the replacement does not impair the essence of the present invention.

Further, in the first embodiment, the description will be made based on the case where the present invention is applied to the uplink transmission having a communication interval (transmission from the wireless terminal 20 to the wireless base station 10 having a communication interval). However, it should be noted that the present invention can be similarly applied to downlink transmission having a communication interval (transmission from the radio base station 10 to the wireless terminal 20 having a communication interval).

FIG. 5 shows an example of the processing sequence of the wireless communication system according to the first embodiment.

In S301, the radio base station 10 allocates radio resources for transmission having a communication interval by the radio terminal 20 to the radio terminal 20. The radio base station 10 allocates the radio resource for transmission having a communication interval by transmitting information indicating the radio resource for transmission having a communication interval (hereinafter, referred to as resource information for convenience) to the radio terminal 20. Will be done.

Here, the resource information shall include at least information indicating the communication interval of the radio resource. The information indicating the communication interval of the radio resource can be, for example, the number of communication sections (N, which is a positive integer of 2 or more).

Further, the resource information includes at least information indicating a communication section to which radio resources are allocated at each communication interval (each N communication section) (hereinafter, referred to as communication section instruction information for convenience). The communication section instruction information can be rephrased as information indicating a communication section that can be transmitted by the wireless terminal 20 at each communication interval (each N communication section). Some examples can be considered as the communication section instruction information. For example, assuming that radio resources for transmission having a communication interval at each communication interval are allocated on continuous communication sections, the communication section instruction information is the number of the continuous communication sections (1 or more is N). Let it be M, which is a positive integer less than or equal to -1).

On the other hand, without the above premise, the radio resource for transmission having a communication interval at each communication interval may be allocated on a non-continuous communication section. As an example in this case, the communication section instruction information can be an N-bit bitmap. Each bit in the N-bit bitmap indicates the presence or absence of radio resource allocation in each of the N communication sections corresponding to each communication interval. When an N-bit bitmap is adopted, the length of the bitmap indicates the communication interval, so that it is not necessary to include separate information indicating the communication interval in the resource information.

Further, the resource information transmitted by the radio base station 10 in S301 may include information related to radio resources used for transmission having a communication interval other than the above-mentioned information indicating the communication interval and the communication section instruction information. For example, the resource information may include information (for example, frequency information and time information) for identifying the radio resource assigned to the communication section indicated by the communication section instruction information. Further, the resource information may include information indicating the timing of the first transmission in the transmission having a communication interval (for example, offset information of the communication section).

Next, in each of S302 to S308, the radio terminal 20 transmits to the radio base station 10 based on the radio resource having the communication interval allocated in S301. In other words, in each of S302 to S308, the wireless terminal 20 transmits to the wireless base station 10 with a communication interval based on the resource information received in S301. Here, as described above, the resource information includes at least information indicating a communication interval and communication section instruction information. Therefore, in each of S302 to S308, the wireless terminal 20 communicates with the wireless base station 10 in the communication section specified by the information indicating the communication interval included in the resource information received in S301 and the communication section instruction information. Make a transmission with.

FIG. 6 shows an enlarged view corresponding to S302 to S304 of FIG. As an example, FIG. 6 shows a case where the communication interval N in the transmission performed by the wireless terminal 20 is 20 communication sections. Further, FIG. 6 shows, as an example, the number M of the continuous communication sections indicated by the communication section instruction information on the premise that the radio resources for communication are arranged on the continuous communication sections at each communication interval. Is shown in the case of 8. At this time, as shown in S302 to S304 of FIG. 6, the wireless terminal 20 can transmit to the wireless base station 10 in the communication intervals of 20 communication sections and in 8 consecutive communication sections in each communication interval.

According to the wireless communication system according to the first embodiment described above, when the wireless base station 10 allocates wireless resources for transmission having a communication interval, it is possible to allocate wireless resources across a plurality of communication sections at each communication interval. It will be possible. This makes it possible to flexibly allocate radio resources in transmission with a communication interval in the time direction.

As a result, according to the first embodiment, in the case of transmitting with a communication interval, when transmitting relatively large data in each communication interval, it is possible to divide the data into a plurality of communication sections and transmit the data. .. Therefore, the radio resources reserved in advance in the plurality of communication sections are reduced. As a result, in the transmission having a communication interval, the radio resources in a certain communication section are less likely to be compressed, and the above-mentioned problem can be solved.

Further, the first embodiment can be realized without increasing the amount of signaling as compared with the conventional transmission having a communication interval illustrated in FIG. 1 and the like. Further, when the first embodiment is compared with dynamic scheduling, the amount of signaling can be significantly reduced as compared with the transmission having a conventional communication interval. For example, if it is attempted to realize the transmission of FIG. 2 exemplifying the transmission having a conventional communication interval by dynamic scheduling, it requires three times of signaling, whereas the transmission of FIG. 6 exemplifying the first embodiment will be realized by dynamic scheduling. Then, since signaling is required 24 times, it can be seen that the first embodiment has a large effect of reducing the amount of signaling.

In addition to these, according to the first embodiment, the data to be transmitted at each communication interval can be divided into a plurality of communication sections and transmitted. As a result, when the transmission power is constant, the transmission power per bit increases relatively, so that coverage is improved. In other words, since a modulation method / coding method that is resistant to errors can be used, the effect of improving communication characteristics can be obtained.

[Second Embodiment]
The second embodiment is an embodiment corresponding to a case where the present invention is applied to SPS (Semi-Persistent Scheduling) transmission of LTE. In a word, the conventional SPS shown in FIGS. 1 to 4 is a one-shot type, whereas the SPS of the second embodiment realizes a multi-shot type SPS.

Also in the second embodiment, the description will be given based on the case where the present invention is applied to the upstream SPS transmission. However, it should be noted that the present invention can be similarly applied to downlink SPS transmission.

The premise of the wireless communication system of the second embodiment will be described. The radio resource has a time component, and the unit of the time component is a subframe (1 msec). It is assumed that the radio base station 10 and the radio terminal 20 can transmit and receive in subframe units in the time direction.

FIG. 7 shows an example of the processing sequence of the wireless communication system according to the second embodiment.

In S401, the radio base station 10 transmits an RRC signal including SPS parameters to the radio terminal 20. More specifically, the RRC Connection Setup message, the RRC Connection Reconfiguration message, or the RRC Connection Reestablishment message, which are RRC signals transmitted by the radio base station 10 to the radio terminal 20, each include a Radio Resource Config Dedicated information element. And the Radio Resource Config Dedicated information element can include the SPS-Config information element. This SPS-Config information element contains various parameters related to SPS. Therefore, in S401, the radio base station 10 stores the SPS-Config in any one of the RRC Connection Setup message, the RRC Connection Reconfiguration message, and the RRC Connection Reestablishment message, and transmits the SPS-Config to the radio terminal 20.

Here, for comparison, first, the SPS-Config information element in the conventional LTE system will be described. First, the SPS-Config information element includes the parameters semi Persist Sched C-RNTI, sps-Config DL information element, and sps-Config UL information element. Here, the semi Persist SchedC-RNTI corresponds to the identifier of the wireless terminal 20 in the SPS, and is used when determining whether or not the above-mentioned DCI is addressed to itself. In addition, the sps-Config DL information element and the sps-Config UL information element include various parameters for the downlink SPS and the uplink SPS, respectively. In the following, the explanation will be based on the sps-Config UL information element, but the sps-Config DL information element can be handled in almost the same way.

FIG. 8 shows the sps-Config UL information element in the conventional LTE system. The SPS-Config UL information element contains several parameters related to SPS, and one of them, semi Persist Scheduling Interval UL, is a parameter indicating the communication interval of the uplink SPS. It is stipulated that the semi Persist Scheduling Interval UL can take values of 10, 20, 32, 40, 64, 80, 128, 160, 320, or 640 subframes, respectively. Therefore, the radio base station 10 can notify the radio terminal 20 of the communication interval of the uplink SPS by transmitting an RRC signal in which one of these values is set to the semi Persist Scheduling Interval UL.

On the other hand, FIG. 9 shows the SPS-Config UL information element in the second embodiment. Unlike FIG. 8, the SPS-Config UL information element of FIG. 9 includes the semi Persist Scheduling Interval UL as one of the parameters (underlined part). Here, semi Persist Scheduling Interval UL is a parameter representing the number of consecutive subframes that can be transmitted at each communication interval of the uplink SPS. Here, as an example, it is assumed that transmission is possible only in continuous subframes at each communication interval of SPS, as described in the first embodiment.

The semi Persist Scheduling Interval UL in FIG. 9 is assumed to be 3-bit information as an example. Also, with eight values from 000 to 111 based on 3 bits, the semi Persist Scheduling Interval UL sets 1, 2, 4, 8, and 16 as the number of consecutive subframes that can be transmitted at each uplink SPS communication interval. , 32, 64, 128.

Summarizing the above, in S401, the radio base station 10 has information indicating the communication interval of the SPS (semi Persist Scheduling Interval UL) and information indicating the number of consecutive subframes that can be transmitted at each communication interval of the SPS (semi Persist Scheduling). An RRC signal including Interval UL) is transmitted to the wireless terminal 20. On the other hand, the wireless terminal 20 receives the RRC signal transmitted by the wireless base station 10.

Next, in S402, the radio base station 10 transmits a control signal for activating the SPS to the radio terminal 20. More specifically, the radio base station 10 sets a predetermined value for a predetermined parameter included in DCI (Down link Information), which is downlink control information, and then transmits the SRS to the wireless terminal 20. Activate. Here, activation of SPS corresponds to activating SPS based on the parameters set in S301.

As the DCI in this embodiment, the same DCI as in general LTE can be used. FIGS. 10A to 10B show DCI in this embodiment. DCI defines several formats, each with a different role. When activating the upstream SPS, use DCI format 0. DCI format 0 is the control information used for dynamic scheduling of uplink data, but it is also used for activation of uplink SPS. DCI format 0 includes fields such as NDI, TPC command for scheduled PDSCH, Cyclic shift RM RS, MCS and RV, Resource Block, etc.

By setting the values of these fields of DCI format 0 to the values shown in the "Activation" column of the table shown in FIG. 10A, the radio base station 10 activates the uplink SPS for the radio terminal 20. Can be notified. Here, although the MCS field is a 5-bit field, the first 1 bit is set to 0, and the remaining 4 bits specify the modulation coding method used in SPS. In addition, the Resource Block has a different size depending on the uplink bandwidth (for example, 6 bits when the uplink bandwidth is 50 MHz and 8 bits when the uplink bandwidth is 100 MHz), but each transmission is performed by SPS. A resource block in a subframe (a division of the upstream bandwidth, which is a resource unit in the frequency direction) can be specified.

On the other hand, when activating the downlink SPS, one of DCI formats 1, 1A, 2, 2A, 2B, and 2C is used. By setting the values of these fields of these DCI format 0 to the values indicated by the "Activation" column in the table shown in FIG. 10B, the radio base station 10 activates the downlink SPS for the radio terminal 20. You can notify that you want to.

Next, in S403 to S409 of FIG. 7, the wireless terminal 20 performs transmission based on SPS. These SPS transmissions are executed based on various parameters notified by the RRC signal of S401 and the DCI of S402.

FIG. 11 shows an enlarged view corresponding to S402 to S405 of FIG. As described with reference to FIG. 2, S403, which corresponds to the first transmission based on SPS, is performed four subframes of the subframes in which DCI is transmitted and received in S402. Since the timing difference (in the case of FDD) of these four subframes is a fixed value predetermined in the specifications, the wireless terminal 20 is based on the timing of receiving S402 without receiving an instruction or the like from the wireless base station 10. It is possible to recognize the timing of the first transmission of SPS.

After that, as shown in S403 to S405 of FIG. 11 and S403 to S409 of FIG. 7, the wireless terminal is based on the values of semi Persist Scheduling Interval UL and semi Persist Scheduling Interval UL notified by the RRC signal of S401. 20 transmits to the radio base station 10 based on SPS. As an example, FIG. 11 shows a case where the value of the semi Persist Scheduling Interval UL included in the RRC signal of S401 is 20 subframes. Further, FIG. 11 shows, as an example, the case where the value of the semi Persist Scheduling Interval UL included in the RRC signal of S401 is 8 subframes. At this time, as shown in S403 to S405 of FIG. 11, the wireless terminal 20 can transmit to the wireless base station 10 at a communication interval of 20 subframes and in 8 subframes continuous at each communication interval.

Next, the processing of the transmission of consecutive subframes at each communication interval (for example, the transmission of eight consecutive subframes as shown in S403 of FIG. 11) will be described in detail. Here, for simplification of the description, it is assumed that the data transmitted by the wireless terminal 20 at each communication interval is determined before the transmission of the communication interval. Then, the data to be transmitted at each communication interval shall be divided into subframes of semi Persist Scheduling Interval UL and transmitted.

In S403 or the like, the wireless terminal 20 divides the data transmitted at the communication interval into semi Persist Scheduling Interval ULs and transmits the data in each of the consecutive semi Persist Scheduling Interval UL subframes. In the example of FIG. 11, in S403 or the like, the wireless terminal 20 divides the data to be transmitted at the communication interval into eight and transmits the data in each of eight consecutive subframes. At this time, the wireless terminal 20 encodes and modulates the divided data in each of the semi Persist Scheduling Interval UL subframes based on the MCS specified by the DCI of S402. Further, the wireless terminal 20 maps the coded and modulated divided data to the Resource Block specified by the DCI of S402 in each of the semi Persist Scheduling Interval UL subframes. As described above, the wireless terminal 20 can perform transmission based on SPS corresponding to S403 and the like.

By the way, in the LTE system, retransmission control is performed. Therefore, when the wireless base station 10 receives the data, it transmits an ACK signal or an NACK signal, which is a response signal, to the wireless terminal 20. The ACK signal is a response signal indicating that the data has been successfully received (decoded). On the other hand, the NACK signal is a response signal indicating that data reception (decoding) has failed. The wireless terminal 20 determines whether or not to retransmit the data based on these response signals. In the LTE system, it is stipulated that an ACK signal or a NACK signal is transmitted in the subframe four times after the subframe in which the data is received.

Although the ACK signal and the NACK signal for each data are not shown in FIGS. 7 and 11, the radio base station 10 of the present embodiment transmits the ACK signal or the NACK signal to the wireless terminal 20 according to the reception result. .. Several methods can be considered for transmitting the ACK signal and the NACK signal. As the simplest method, an ACK signal or an NACK signal can be transmitted for each subframe according to a general LTE system (referred to as an individual response method for convenience). In the individual response method, retransmission can also be performed for each subframe. According to the individual response method, in the case shown in FIG. 11, the radio base station 10 needs to transmit an ACK signal or a NACK signal to the radio terminal 20 for each of the eight subframes transmitted by SPS at each communication interval. That is, in the example of FIG. 11, eight ACK signals or NACK signals are required for each communication interval of SPS transmission.

Although the individual response method of transmitting the ACK signal or the NACK signal for each subframe is familiar to the existing LTE system, there is a concern that the amount of signaling becomes enormous. Therefore, a method of transmitting one ACK signal or NACK signal for each communication interval can be considered (for convenience, it is called a batch response method). Explaining based on the example of FIG. 11, the radio base station 10 receives up to the last (eighth) subframe that can communicate at each communication interval, and then receives all the subframes that can communicate at the communication interval. If is successful, send an ACK only once. On the other hand, the radio base station 10 transmits NACK only once when the reception of even one subframe that can communicate at the communication interval fails. However, in the case of the batch response method, if retransmission is required, it is necessary to retransmit eight subframes at once. Therefore, the amount of signaling is reduced, but another problem arises in which the amount of data to be retransmitted increases.

Therefore, a retransmission method that combines an individual response method and a batch response method can be considered. For example, the radio base station 10 transmits an ACK only once at the end when all the subframes that can be transmitted at a certain communication interval are successfully received. On the other hand, if reception fails in any of the subframes that can be transmitted at the communication interval, the radio base station 10 can transmit an ACK signal or an NACK signal for each subframe after that subframe. By doing so, it is possible to suppress the amount of signaling and to perform retransmission for each subframe.

Alternatively, although the ACK signal or NACK signal is a 1-bit signal, it is conceivable to extend this to a plurality of bits. For example, an ACK signal or an NACK signal can be an 8-bit bitmap, and can be associated with the reception result of each of the eight subframes that can be transmitted at each communication interval in FIG. Also in this method, retransmission for each subframe is possible while suppressing the amount of signaling.

In the case of retransmission, the wireless terminal 20 can perform retransmission using the wireless resources allocated from the wireless base station 10 based on dynamic scheduling. It is also possible to perform retransmission using the radio resource of the next communication interval.

Finally, in the second embodiment described above, as an example, a case where it is assumed that transmission is possible only in continuous subframes at each communication interval of SPS transmission is described. However, this premise is not essential in the second embodiment (including other embodiments based on the second embodiment described below). That is, in the second embodiment, transmission may be possible in subframes that are not continuous at each communication interval of SPS transmission.

Specifically, in the above description, the SPS transmission parameter semi Persist Scheduling Interval UL represents the number of consecutive subframes that can be transmitted at each communication interval of the uplink SPS, but is not limited to this. As an example, the semi Persist Scheduling Interval UL can be a bitmap consisting of the number of bits for the communication interval (subframe unit) of SPS transmission. At this time, in the semi Persist Scheduling Interval UL, each bit in the bitmap indicates the presence or absence of radio resource allocation in each communicable subframe at each communication interval. Further, the semi Persist Scheduling Interval UL is used as a bitmap consisting of a predetermined number of bits, and each bit in the bitmap indicates whether or not radio resource allocation is performed in each subframe having a predetermined number of bits from the beginning in each communication interval. Good.

According to the second embodiment described above, various effects similar to those of the first embodiment can be obtained.

That is, according to the wireless communication system according to the second embodiment, when the wireless base station 10 allocates wireless resources for SPS, it is possible to allocate wireless resources spanning a plurality of subframes at each communication interval. This makes it possible to flexibly allocate radio resources for SPS in the time direction.

As a result, according to the second embodiment, when SPS is performed, when relatively large data is transmitted at each communication interval, it is possible to divide the data into a plurality of subframes and transmit the data. Therefore, the radio resources reserved in advance in the plurality of subframes become small. As a result, in SPS, the radio resources of a certain subframe are less likely to be overwhelmed, and the above-mentioned problems can be solved.

Further, the second embodiment can be realized without increasing the amount of signaling as compared with the conventional SPS illustrated in FIG. 1 and the like. Further, when the second embodiment is compared with dynamic scheduling, the amount of signaling can be significantly reduced as compared with the conventional SPS. For example, when the transmission of FIG. 2 exemplifying the conventional SPS is realized by dynamic scheduling, signaling is required three times, whereas when the transmission of FIG. 11 exemplifying the second embodiment is realized by dynamic scheduling, 24 times. It can be seen that the second embodiment has a large effect of reducing the amount of signaling because it requires signaling.

In addition to these, according to the second embodiment, the data to be transmitted at each communication interval can be divided into a plurality of subframes and transmitted. As a result, when the transmission power is constant, the transmission power per bit increases relatively, so that coverage is improved. In other words, since a modulation method / coding method that is resistant to errors can be used, the effect of improving communication characteristics can be obtained.

[Third Embodiment]
The third embodiment is a modification applicable to the first embodiment or the second embodiment. Hereinafter, a modified example based on the second embodiment will be described as an example of the third embodiment, but a modified example based on the first embodiment can be configured in the same manner.

Also in the third embodiment, the description will be given based on the case where the present invention is applied to the upstream SPS transmission. However, it should be noted that the present invention can be similarly applied to downlink SPS transmission. Further, as shown in the first embodiment, it goes without saying that the present invention is generally applicable not only to SPS in LTE but also to communication having a communication interval.

FIG. 12 shows an example of the processing sequence of the wireless communication system according to the third embodiment. FIG. 12 corresponds to individual SPS transmissions (for example, S403 in FIG. 11) in the SPS of the second embodiment. As an example, the SPS transmission shown in FIG. 12 is based on the premise that the value of the semi Persist Scheduling Interval UL in the second embodiment is 8 subframes. In other words, S501 to S508 of FIG. 12 correspond to eight consecutive subframes transmitted in S403 and the like of FIG. It should be noted that the number of eight is only an example here, and it goes without saying that the present embodiment can be applied to other numbers.

The premise of the third embodiment will be described. In the second embodiment, the data transmitted at each communication interval of the SPS is divided and transmitted in all of the continuous semi Persist Scheduling Interval UL subframes. On the other hand, in the third embodiment, it is not necessary to divide and transmit the data transmitted at each communication interval of the SPS in all of the continuous semi Persist Scheduling Interval UL subframes. In the third embodiment, the data to be transmitted at each communication interval of SPS is divided into an arbitrary number of subframes from the beginning among the semi Persist Scheduling Interval UL subframes that can be transmitted continuously at each communication interval. Can be sent.

For example, in SPS, it is possible that the data to be transmitted happens to be small. In such a case, it is less necessary to divide the small data into many subframes and transmit the data. Rather, it is considered that it is often desirable to divide such small data into the minimum necessary frames and transmit it because it is possible to suppress an increase in power consumption due to an increase in the number of transmissions. Based on this reason, in the present embodiment, as described above, it is necessary to divide and transmit the data to be transmitted at each communication interval of SPS in all the continuous subframes that can be transmitted at each communication interval. I will not do it.

In S501 to S502 of FIG. 12, the wireless terminal 20 performs SPS transmission in the first two subframes among the subframes that can be transmitted at a certain communication interval. Here, it goes without saying that two is an example and other numbers may be used.

In S503 of FIG. 12, the wireless terminal 20 notifies the wireless base station 10 of the end of transmission indicating that the SPS transmission in the communication interval has ended. The notification indicating the end of transmission (hereinafter referred to as the transmission end notification) can be performed using, for example, a radio resource for SPS transmission. It is considered inefficient to allocate the radio resource for this notification separately. As the transmission end notification, for example, a BSR (Buffer Status Report) indicating the data size of the uplink data in which the buffer size is set to 0 can be used. Since the BSR is information transmitted via PUSCH, the transmission end notification using the BSR can be performed using the radio resource for SPS transmission. The transmission end notification using BSR may be transmitted in the subframe next to the subframe in which the data was transmitted last, or may be stored in an empty part of the subframe in which the data is transmitted last and transmitted. You can also.

In S504 to S508 of FIG. 12, the wireless terminal 20 does not perform SPS transmission. In S504 to S508, the radio base station 10 also does not perform SPS reception processing. This is because the transmission end notification of S503 allows the wireless base station 10 to recognize in advance that the wireless terminal 20 does not transmit in the subframes of S504 to S508.

When BSR is used as the transmission end notification of S503, SPS is temporarily released. Therefore, the wireless terminal 20 not only does not perform transmission in S504 to S508, but also does not perform SPS transmission in the communication interval after the communication interval corresponding to S501 to S508. In this case, the wireless base station 10 can restart the SPS transmission in the wireless terminal 20 by activating the SPS again in the wireless terminal 20.

According to the third embodiment shown in FIG. 12, the wireless terminal 20 can reduce the number of transmissions in each communication interval of SPS transmission as needed, and the power consumption of the wireless terminal 20 can be reduced.

In the above description, the BSR is used as the transmission end notification of S503, but in S503, the wireless terminal 20 can also notify the wireless base station 10 of the transmission end by another method. As an example, the wireless terminal 20 can notify the wireless base station 10 of the end of transmission by not transmitting in the subframe of S503. Further, the wireless base station 10 may be notified of the end of transmission by not performing transmission in a predetermined number of subframes including S503. In this case, the predetermined number can be the number of subframes indicated by implicit Release After, which is a parameter included in SPS-Config UL shown in FIG. The fact that the wireless terminal 20 does not transmit in implicit release after subframes indicates that the wireless terminal 20 explicitly releases SPS transmission. Therefore, in this case, SPS is released once. By activating the SPS for the wireless terminal 20 again, the wireless base station 10 can restart the SPS transmission to the wireless terminal 20.

Further, as the transmission end notification of S503, a new signal for notifying the transmission end may be defined and used. This new signal may be transmitted via PUCCH, for example, or may be transmitted via PUSCH. When transmitting via PUSCH, for example, it can be performed using a radio resource for SPS transmission. It is considered inefficient to allocate the radio resource for this notification separately.

Further, when this new signal is used as the transmission end notification of S503, the SPS may not be released. In this case, the wireless terminal 20 does not perform transmission in S504 to S508, but performs SPS transmission in the communication interval after the communication interval corresponding to S501 to S508. In other words, since the SPS transmission is not released once, the wireless terminal 20 can continue the SPS transmission without the radio base station 10 activating the SPS for the wireless terminal 20 again.

Next, a further modification of the third embodiment will be described. In the third embodiment shown in FIG. 12, the wireless terminal 20 does not transmit in S504 to S508, but the wireless resource for transmitting at this time is already allocated by the RRC signal and DCI in advance. That is, in S504 to S508 of FIG. 12, since the wireless terminal 20 does not perform transmission, the already allocated wireless resource is wasted. This is not preferable from the viewpoint of efficient use of wireless resources. Therefore, in the modification of the third embodiment described below, the radio base station 10 can allocate the radio resource that the radio terminal 20 does not transmit to another radio terminal. As a result, it is considered that the empty cost of the wireless resource can be suppressed, and the wireless resource can be efficiently used while suppressing the amount of signaling.

FIG. 13 shows an example of the processing sequence of the wireless communication system according to the modified example of the third embodiment. Since two wireless terminals 20 appear in FIG. 13 and FIG. 14 described later, one is referred to as a wireless terminal 20a and the other is referred to as another wireless terminal 20b for convenience.

In FIG. 13 and the following description, when alphabetic characters are added to the numbers assigned to each process in the figure, it is assumed that the processes having the same number are executed at the same subframe timing. For example, S604a and S604b are executed at the same subframe timing.

Since S601a to S603a in FIG. 13 are the same processes as S501 to S503 in FIG. 12, description thereof will be omitted here.

In S604a to S608a of FIG. 13, the wireless terminal 20a does not transmit, as in S504 to S508 of FIG. On the other hand, in S604b, the radio base station 10 transmits a UL Grant to another radio terminal 20b other than the radio terminal 20a. In this UL Grant, the radio base station 10 specifies the radio resources for uplink transmission to be allocated to the other radio terminal 20b, but all or part of the radio resources are released by the radio resources for SPS transmission of the radio terminal 20a. Can be used. The specifications stipulate that the radio resource specified by UL grant is a radio resource on the subframe four times after the subframe to which the UL grant is transmitted. Therefore, the radio base station 10 can allocate the released resources to the other radio terminal 20b by using UL grant only when the released radio resources are after 4 subframes.

In S608b of FIG. 13, the other wireless terminal 20b transmits uplink data to the wireless base station 10 based on the UL Grant of S604b. As described above, S608b corresponds to four subframes after S604b. As a result, the wireless resources for uplink transmission released by the wireless terminal 20a can be allocated to the other wireless terminal 20b, so that the uplink wireless resources can be efficiently used.

The released wireless resource for uplink can be reused for downlink communication for another wireless terminal 20b. When the radio terminal 20a transmits the release in a certain subframe, the radio base station 10 can detect the release request in the subframe. Then, the released wireless resource can be used as a downlink resource for another wireless terminal 20b. Specifically, in the next subframe, the radio resource for transmitting PDSCH is specified by PDCCH.

By the way, FIG. 13 shows a modified example of the third embodiment based on the upstream SPS. On the other hand, FIG. 14 shows an example of the processing sequence of the wireless communication system according to the modified example of the third embodiment based on the downlink SPS. In S701a to S702a, the radio base station 10 performs downlink SPS transmission, and in S703a, the radio base station 10 notifies the radio terminal 20a of the end of transmission.

As described above, in the case of uplink, a time lag of 4 subframes is required between the allocation of radio resources by the radio base station 10 (UL Grant) and the uplink transmission corresponding to the allocation. On the other hand, in the case of downlink, the allocation of radio resources (DCI) by the radio base station 10 and the downlink data transmission are performed in the same subframe. Therefore, as illustrated in S704b to S706b of FIG. 14, the radio base station 10 allocates downlink resources and transmits downlink data to another wireless terminal 20b from the next subframe after transmitting the transmission end notification. Can be done.

According to the modified example of the third embodiment shown in FIGS. 13 to 14, the wireless terminal 20a can reduce the number of transmissions in each communication interval of SPS transmission as necessary, and the wireless terminal can be reduced as necessary. The power consumption of 20a can be reduced. Further, according to the modified example of the third embodiment, it is possible to allocate the wireless resource for SPS transmission that is not transmitted to another wireless terminal 20b. As a result, the empty cost of the wireless resource for SPS transmission is suppressed, which has the effect of enabling efficient use of the wireless resource.

[Fourth Embodiment]
The fourth embodiment is a modification applicable to the first to third embodiments. Hereinafter, a modified example based on the second embodiment will be described as an example of the fourth embodiment, but a modified example based on the first embodiment and a modified example based on the third embodiment can be configured in the same manner. ..

Also in the fourth embodiment, the description will be given based on the case where the present invention is applied to the upstream SPS transmission. However, it should be noted that the present invention can be similarly applied to downlink SPS transmission. Further, as shown in the first embodiment, it goes without saying that the present invention is generally applicable not only to SPS in LTE but also to communication having a communication interval.

FIG. 15 shows an example of the processing sequence of the wireless communication system according to the fourth embodiment. FIG. 15 corresponds to individual SPS transmissions (for example, S403 in FIG. 11) in the SPS of the second embodiment.

FIG. 15 shows an example of the processing sequence of the wireless communication system according to the fourth embodiment. FIG. 15 corresponds to individual SPS transmissions (for example, S403 in FIG. 11) in the SPS of the fourth embodiment. As an example, the SPS transmission shown in FIG. 15 is premised on the value of the semi Persist Scheduling Interval UL in the second embodiment being 8 subframes. In other words, S801 to S808 of FIG. 15 correspond to eight consecutive subframes transmitted in S403 and the like of FIG. It should be noted that the number of eight is only an example here, and it goes without saying that the present embodiment can be applied to other numbers.

In S801 to S806 of FIG. 15, the wireless terminal 20 performs SPS transmission in the first six subframes out of eight consecutive subframes that can be transmitted at a certain communication interval. Here, it goes without saying that 6 is an example and other numbers may be used.

In S807 of FIG. 15, the wireless terminal 20 transmits an extension request to extend the SPS transmission to the wireless base station 10. This extension request can be realized by, for example, SR (Scheduling Request), which is a control signal used in conventional dynamic scheduling. In this case, it is desirable that the system policy presupposes that the radio base station 10 does not perform dynamic scheduling on a predetermined radio terminal 20 (for example, an MTC device) during SPS transmission. This is because the MTC device during SPS transmission does not need to transmit SR for dynamic scheduling, and SR can be used as a control signal for SPS extension. On the other hand, even with such a premise, it is considered that there is little harmful effect because the normal MTC device does not cause irregular transmission such as Web traffic and dynamic scheduling is considered unnecessary. If SR is used as an extension request for SPS transmission under the above premise, when SR is received from an MTC device in which SPS is being executed, the radio base station 10 is requested to extend SPS without performing normal dynamic scheduling. It can be recognized as a new one.

Further, the signal for requesting extension of S807 can be defined separately from SR. The signal for the extension request may be transmitted via PUCCH, for example, or may be transmitted via PUSCH. When transmitting via PUSCH, for example, it can be performed using a radio resource for SPS transmission. It is considered inefficient to allocate the radio resource for this notification separately.

In S808 of FIG. 15, the radio base station 10 transmits an extension response in response to the extension request of S807. As the prolongation response, for example, DCI used for (re) activating SPS can be used. DCI can be transmitted via PDCCH.

Further, as the extended response, a signal different from DCI can be newly defined and used. In this case, the extended response may include information indicating whether to allow the extension of the SPS transmission. Further, the extended response may specify a period for extending the SPS (for example, the number of subframes). The extended response may be transmitted via PDCCH, for example, or may be transmitted via PDSCH.

Although not shown in FIG. 15, the wireless terminal 20 may transmit uplink data in the same subframe as S808. It should be noted that since the subframe of S808 corresponds to the SPS transmission before the extension, the wireless terminal 20 can transmit in the S808 regardless of whether or not the extension of the SPS transmission is permitted by the radio base station 10. ..

Then, in S809 to S810 of FIG. 15, the wireless terminal 20 performs the extended SPS transmission. The extension period of SPS transmission may or may not be fixed. As described above, the extension period of the SPS transmission may be specified from the radio base station 10 to the radio terminal 20 by an extension request, or may be notified by any other downlink signal. In FIG. 15, the extended SPS transmission is performed by two subframes, but it goes without saying that this number is only an example.

In FIG. 15, the extended response of S808 may be omitted. The extended response also has an aspect of a response signal to the extension request, but especially when the extended response is transmitted via the PUCCH by SR or the like, the PUCCH has a low error rate, so the significance of the response signal is not very high. When the extension response is omitted, the wireless terminal 20 can recognize that the extension request is not permitted because the ACK is not returned for the extended SPS transmission.

According to the fourth embodiment described above, the SPS transmission at a certain communication interval can be extended. In other words, according to the fourth embodiment, it is possible to increase the number of subframes that perform SPS transmission at a certain communication interval as needed.

[Fifth Embodiment]
The fifth embodiment is a modification in which the present invention is combined with intermittent reception. The fifth embodiment can be appropriately combined with the second to fourth embodiments.

Also in the fifth embodiment, the description will be given based on the case where the present invention is applied to the upstream SPS transmission. However, it should be noted that the present invention can be similarly applied to downlink SPS transmission. Further, as shown in the first embodiment, it goes without saying that the present invention is generally applicable not only to SPS in LTE but also to communication having a communication interval.

In LTE systems, a function called Discontinous Reception (DRX) has been introduced. DRX is a technology for reducing the power consumption of the wireless terminal 20 during communication. Since the wireless terminal 20 during communication needs to receive a control signal (PDCCH) or the like which is a signal indicating data communication due to the intermittentness of data communication, the power of the communication function cannot be completely turned off. However, it is not preferable in terms of power consumption that the wireless terminal 20 during communication always turns on the power of the communication function. Therefore, in DRX, it is decided to intermittently perform reception processing of control signals, etc., provide an essential section for reception, monitor control signals, etc. in that section, and power the communication function during the period when reception is not performed. By turning off, the power consumption of the wireless terminal 20 during communication is reduced.

Although DRX realizes intermittent reception, it is also possible to perform intermittent transmission (DTX: Discontinous Transmission) in accordance with DRX. This is because the power of the communication function is turned on during the reception period in the DRX. Thereby, the SPS and the DRX can be combined, and the invention of the present application based on the SPS and the DRX can be combined.

FIG. 16 shows an example of a processing sequence of the wireless communication system according to the fifth embodiment, which is a combination of the present invention according to the second embodiment and the DRX. As shown in FIG. 16, the wireless terminal 20 performing DRX performs reception (activity) and pause based on a reception period and a pause period repeated in a cycle called a DRX cycle. In FIG. 16, for convenience, the reception period is represented by ON and the pause period is represented by OFF. Specifically, S901b, S903b, and S905b in FIG. 16 correspond to the reception period, and S902b and S904b correspond to the rest period, respectively. Here, since the reception period of DRX is called active time in the LTE specifications, this term will be used hereafter.

In the example of FIG. 16, the transmission period of the SPS of the present invention and the activity time of the DRX coincide with each other. Specifically, the timings are such that S901a and S901b, S903a and S903b, and S905a and S905b in FIG. 16 coincide with each other. In other words, it can be said that DRX and SPS are linked. Here, the SPS transmission shown in FIG. 16 is based on the premise that the value of the semi Persist Scheduling Interval UL, which is a parameter of the SPS transmission, is 8 subframes, as an example. The DRX activity time is set by the radio base station 10 transmitting an RRC signal to the radio terminal 20. Since it is the wireless base station 10 that determines various settings for both the DRX and the SPS, the wireless base station 10 can link the DRX and the SPS in the wireless terminal 20 as shown in FIG.

Note that FIG. 16 is an example of a combination of the present invention based on SPS and DRX, and the activity time of DRX and the transmission period of SPS of the present invention do not necessarily have to match. However, the SPS transmission period must be included in the DRX activity time. This is because the communication function of the wireless terminal 20 is turned off during a period other than the DRX activity time, so that it is impossible to perform SPS transmission.

Here, when the invention of the present application based on SPS and DRX are combined, it is considered that the SPS transmission period is extended as in the fourth embodiment. FIG. 17 shows an example of a processing sequence of a wireless communication system related to an extension of the SPS transmission period of the fifth embodiment, which is a combination of the present invention according to the second embodiment and DRX. FIG. 17 is an enlarged view of SPS transmission and DRX reception (for example, S801a and S801b in FIG. 16) for one communication interval. Also, as an example, it is assumed that the value of semi Persist Scheduling Interval UL, which is a parameter of SPS transmission, is 8 subframes.

In S1001 to S1007 of FIG. 17, the wireless terminal 20 transmits uplink data based on SPS. Then, in S1008 of FIG. 17, the wireless terminal 20 transmits the same SPS transmission extension request as in S807 of FIG. 15 to the wireless base station 10. However, SR is used for the extension request of S1008. In the extension request of S807, SR was only one example, but in S1008, it is necessary to use SR.

Here, S1008 in FIG. 17 is the last subframe that can be transmitted at a certain communication interval of SPS, and is the last subframe of the DRX activity time. Therefore, even if the extension request to the SPS is transmitted by using the SR in S1008, the power of the communication function is turned off by the end of the DRX activity time in S1009, so that the wireless terminal 20 cannot receive the extension response. It seems to be.

However, in LTE, when the wireless terminal 20 transmits SR, it is stipulated that the activity time of DRX is extended as shown in FIG. 17 (provided that SR is pending). Further, in LTE, it is stipulated that the wireless terminal 20 monitors (receives) PDCCH during the activity time of DRX. Therefore, in S1009 of FIG. 17, when the radio base station 10 transmits an extended response via PDCCH, for example, using DCI for (re) activating SPS, the wireless terminal 20 can receive the extended response. become. As a result, in S101 to S1011 the wireless terminal 20 can perform the extended SPS transmission in the extended DRX activity time.

According to the fifth embodiment described above, when the present invention and DRX are combined, the SPS transmission period can be extended by extending the DRX activity time without requiring separate signaling. Become.

[Network Configuration of Wireless Communication System of Each Embodiment]
Next, the network configuration of the wireless communication system 1 of the first embodiment will be described with reference to FIG. As shown in FIG. 18, the wireless communication system 1 has a wireless base station 10 and a wireless terminal 20. The radio base station 10 forms the cell C10. The wireless terminal 20 exists in cell C10. It should be noted that in the present application, the radio base station 10 may be referred to as a “transmitting station” and the radio terminal 20 may be referred to as a “receiving station”.

The wireless base station 10 is connected to the network device 3 via a wired connection, and the network device 3 is connected to the network 2 via a wired connection. The radio base station 10 is provided so as to be able to transmit and receive data and control information to and from other radio base stations via the network device 3 and the network 2.

The wireless base station 10 may separate the wireless communication function with the wireless terminal 20 and the digital signal processing and control function into separate devices. In this case, a device having a wireless communication function is called an RRH (Remote Radio Head), and a device having a digital signal processing and control function is called a BBU (Base Band Unit). The RRH is installed so as to project from the BBU, and a wired connection may be made between them by an optical fiber or the like. Further, the radio base station 10 is a radio base station of various scales in addition to small radio base stations (including micro radio base stations, femto radio base stations, etc.) such as macro radio base stations and pico radio base stations. Good. Further, when a relay station that relays wireless communication between the wireless base station 10 and the wireless terminal 20 is used, the relay station (transmission / reception with the wireless terminal 20 and its control) is also included in the wireless base station 10 of the present application. May be.

On the other hand, the wireless terminal 20 communicates with the wireless base station 10 by wireless communication.

The wireless terminal 20 may be a wireless terminal such as a mobile phone, a smartphone, a PDA (Personal Digital Assistant), a personal computer (Personal Computer), and various devices and devices (sensor devices and the like) having a wireless communication function. Further, when a relay station that relays wireless communication between the wireless base station 10 and the wireless terminal is used, the relay station (transmission and reception with the wireless base station 10 and its control) is also included in the wireless terminal 20 of this paper. May be good.

The network device 3 includes, for example, a communication unit and a control unit, and each of these components is connected so that signals and data can be input and output in one direction or both directions. The network device 3 is realized by, for example, a gateway. As a hardware configuration of the network device 3, for example, the communication unit is realized by an interface circuit, and the control unit is realized by a processor and a memory.

The specific embodiment of the distribution / integration of each component of the wireless base station and the wireless terminal is not limited to the embodiment of the first embodiment, and all or a part thereof may be used according to various loads, usage conditions, and the like. , It can be functionally or physically distributed / integrated in any unit. For example, the memory may be connected via a network or a cable as an external device of a wireless base station or a wireless terminal.

[Functional configuration of each device in the wireless communication system of each embodiment]
Next, the functional configuration of each device in the wireless communication system of each embodiment will be described with reference to FIGS. 19 to 20.

FIG. 19 is a functional block diagram showing the configuration of the radio base station 10. As shown in FIG. 19, the radio base station 10 includes a transmitting unit 11, a receiving unit 12, and a control unit 13. Each of these components is connected so that signals and data can be input and output in one direction or both directions. The transmitting unit 11 and the receiving unit 12 are collectively referred to as a communication unit 14.

The transmission unit 11 transmits the data signal and the control signal via the antenna by wireless communication. The antenna may be common to both transmission and reception. The transmission unit 11 transmits a downlink signal via, for example, a downlink data channel or a control channel. The downlink physical data channel includes, for example, an individual data channel PDSCH (Physical Downlink Shared Channel). Further, the downlink physical control channel includes, for example, an individual control channel PDCCH (Physical Downlink Control Channel). The signals to be transmitted include, for example, an L1 / L2 control signal transmitted to the connected wireless terminal 20 on the individual control channel, a user data signal transmitted to the connected wireless terminal 20 on the individual data channel, and an RRC (Radio). Resource Control) Contains control signals. Also, the signal to be transmitted includes, for example, a reference signal used for channel estimation and demodulation.

Specific examples of the signal transmitted by the transmission unit 11 include each signal transmitted by each radio base station 10 in FIGS. 1 to 7 or 11 to 17. Specifically, the transmission unit 11 can transmit the SPS parameter notification in FIGS. 1, 3 and 7 to the wireless terminal 20 by RRC signaling via PDSCH. The transmission unit 11 can transmit the SPS activation and SPS release in FIGS. 1 to 4, 7 and 11 to the wireless terminal 20 via the PDCCH. The transmission unit 11 can transmit the downlink SPS-based transmission in FIGS. 3 to 4 and 14 to the wireless terminal 20 via the PDSCH. The transmission unit 11 can transmit the transmission parameter notification shown in FIG. 5 to the wireless terminal 20. The transmission unit 11 can transmit the UL Grant in FIG. 13 to the wireless terminal 20 (corresponding to another wireless terminal 20b in FIG. 13) via the PDCCH. The transmission unit 11 can transmit the transmission end notification in FIG. 14 to the wireless terminal 20 via, for example, PDCCH or PDSCH. The transmission unit 11 can transmit the DCI in FIG. 14 to the wireless terminal 20 (corresponding to another wireless terminal 20b in FIG. 13) via the PDCCH. The transmission unit 11 can transmit the downlink data transmission in FIG. 14 to the wireless terminal 20 (corresponding to another wireless terminal 20b in FIG. 13) via the PDSCH. The transmission unit 11 can transmit the extended response shown in FIGS. 15 and 17 to the wireless terminal 20 via, for example, PDCCH.

The receiving unit 12 receives the data signal and the control signal transmitted from the wireless terminal 20 by the first wireless communication via the antenna. The receiving unit 12 receives an uplink signal via, for example, an uplink data channel or a control channel. The upstream physical data channel includes, for example, an individual data channel PUSCH (Physical Uplink Shared Channel). Further, the upstream physical control channel includes, for example, an individual control channel PUCCH (Physical Uplink Control Channel). The received signal is, for example, an L1 / L2 control signal transmitted from the connected wireless terminal 20 on the individual control channel, a user data signal transmitted from the connected wireless terminal 20 on the individual data channel, or an RRC (Radio). Resource Control) Contains control signals. The received signal also includes, for example, a reference signal used for channel estimation and demodulation.

Specific examples of the signal transmitted by the receiving unit 12 include each signal received by each radio base station 10 in FIGS. 1 to 7 or 11 to 17. Specifically, the receiving unit 12 can receive the transmission based on the uplink SPS in FIGS. 1 to 2, 7, 11, 13 and 15 to 17 from the wireless terminal 20 via the PUSCH. .. The receiving unit 12 can receive the uplink transmission shown in FIGS. 5 to 6 from the wireless terminal 20. The receiving unit 12 can receive the transmission end notification in FIGS. 12 to 13 from the wireless terminal 20 via, for example, PUSCH. The receiving unit 12 can receive the uplink data transmission in FIG. 13 from the wireless terminal 20 (corresponding to another wireless terminal 20b in FIG. 13) via, for example, PUSCH. The receiving unit 12 can receive the extension request in FIGS. 15 and 17 from the wireless terminal 20 via, for example, PUCCH.

The control unit 13 outputs the data to be transmitted and the control information to the transmission unit 11. The control unit 13 inputs received data and control information from the reception unit 12. The control unit 13 acquires data and control information from the network device 3 and other wireless base stations via a wired connection or a wireless connection. In addition to these, the control unit performs various controls related to various transmission signals transmitted by the transmission unit 11 and various reception signals received by the reception unit 12.

Specific examples of the processes controlled by the control unit 13 include various processes executed by each radio base station 10 in FIGS. 1 to 7 and 11 to 17. Specifically, the control unit 13 can control the transmission process of the SPS parameter notification in FIGS. 1, 3 and 7. The control unit 13 can control the transmission processing of SPS activation and SPS release in FIGS. 1 to 4, 7 and 11. The control unit 13 can control the transmission process based on the downlink SPS in FIGS. 3 to 4 and 14. The control unit 13 can control the transmission process of the transmission parameter notification in FIG. The control unit 13 can control the UL Grant transmission process in FIG. The control unit 13 can control the transmission process of the transmission end notification in FIG. The control unit 13 can control the DCI transmission process in FIG. The control unit 13 can control the transmission process of the downlink data transmission in FIG. The control unit 13 can control the transmission process of the extended response in FIGS. 15 and 17. The control unit 13 can control the reception process based on the uplink SPS in FIGS. 1 to 2, 7, 11, 11 to 13, and 15 to 17. The control unit 13 can control the reception process of the uplink transmission in FIGS. 5 to 6. The control unit 13 can control the reception process of the transmission end notification in FIGS. 12 to 13. The control unit 13 can control the reception process of the upstream data transmission in FIG. The control unit 13 can control the reception process of the extension request in FIGS. 15 and 17.

FIG. 20 is a functional block diagram showing the configuration of the wireless terminal 20. As shown in FIG. 20, the wireless terminal 20 includes a transmission unit 21, a reception unit 22, and a control unit 23. Each of these components is connected so that signals and data can be input and output in one direction or both directions. The transmitting unit 21 and the receiving unit 22 are collectively referred to as a communication unit 24.

The transmission unit 21 transmits the data signal and the control signal via the antenna by wireless communication. The antenna may be common to both transmission and reception. The transmission unit 21 transmits an uplink signal via, for example, an uplink data channel or control channel. The upstream physical data channel includes, for example, an individual data channel PUSCH (Physical Uplink Shared Channel). Further, the upstream physical control channel includes, for example, an individual control channel PUCCH (Physical Uplink Control Channel). The signals to be transmitted include, for example, an L1 / L2 control signal transmitted to the connected wireless base station 10 on the individual control channel, a user data signal transmitted to the connected wireless base station 10 on the individual data channel, and an RRC (Radio). Resource Control) Contains control signals. Also, the signal to be transmitted includes, for example, a reference signal used for channel estimation and demodulation.

Specific examples of the signal transmitted by the transmission unit 21 include each signal transmitted by each wireless terminal 20 in FIGS. 1 to 7 or 11 to 17. Specifically, the transmission unit 21 transmits the uplink SPS-based transmissions in FIGS. 1 to 2, 7, 11, 13 and 15 to 17 to the radio base station 10 via PUSCH. sell. The transmission unit 21 can transmit the uplink transmission shown in FIGS. 5 to 6 to the radio base station 10. The transmission unit 21 can transmit the transmission end notification in FIGS. 12 to 13 to the radio base station 10 via, for example, PUSCH. The transmission unit 21 can transmit the uplink data transmission shown in FIG. 13 to the radio base station 10 via, for example, PUSCH. The transmission unit 21 can transmit the extension request in FIGS. 15 and 17 to the radio base station 10 via, for example, PUCCH.

The receiving unit 22 receives the data signal and the control signal transmitted from the wireless base station 10 by wireless communication via the antenna. The receiving unit 22 receives a downlink signal via, for example, a downlink data channel or a control channel. The downlink physical data channel includes, for example, an individual data channel PDSCH (Physical Downlink Shared Channel). Further, the downlink physical control channel includes, for example, an individual control channel PDCCH (Physical Downlink Control Channel). The received signal is, for example, an L1 / L2 control signal transmitted from the connected wireless base station 10 on the individual control channel, a user data signal transmitted from the connected wireless base station 10 on the individual data channel, or an RRC (Radio). Resource Control) Contains control signals. The received signal also includes, for example, a reference signal used for channel estimation and demodulation.

Specific examples of the signal received by the receiving unit 22 include each signal received by each wireless terminal 20 in FIGS. 1 to 7 or 11 to 17. Specifically, the receiving unit 22 can receive the SPS parameter notifications in FIGS. 1, 3, 7, and 7 from the radio base station 10 by RRC signaling via PDSCH. The receiving unit 22 can receive the SPS activation and SPS release in FIGS. 1 to 4 and 11 from the radio base station 10 via the PDCCH. The receiving unit 22 can receive the downlink SPS-based transmissions in FIGS. 3 to 4 and 14 from the radio base station 10 via the PDSCH. The receiving unit 22 can receive the transmission parameter notification shown in FIG. 5 from the radio base station 10. The receiving unit 22 can receive the UL Grant shown in FIG. 13 from the radio base station 10 via the PDCCH. The receiving unit 22 may receive the transmission end notification in FIG. 14 from the radio base station 10 via, for example, PDCCH or PDSCH. The receiving unit 22 can receive the DCI shown in FIG. 14 from the radio base station 10 via the PDCCH. The receiving unit 22 can receive the downlink data transmission in FIG. 14 from the radio base station 10 via the PDSCH. The receiving unit 22 may receive the extended response in FIGS. 15 and 17 from the radio base station 10 via, for example, the PDCCH.

The control unit 23 outputs the data to be transmitted and the control information to the transmission unit 21. The control unit 23 inputs received data and control information from the reception unit 22. The control unit 23 acquires data and control information from the network device 3 and other wireless base stations via a wired connection or a wireless connection. In addition to these, the control unit performs various controls related to various transmission signals transmitted by the transmission unit 21 and various reception signals received by the reception unit 22.

Specific examples of the processes controlled by the control unit 23 include various processes executed by the wireless terminals 20 in FIGS. 1 to 7 and 11 to 17. Specifically, the control unit 23 can control the reception process of the SPS parameter notification in FIGS. 1, 3 and 7. The control unit 23 can control the reception processing of SPS activation and SPS release in FIGS. 1 to 4, 7 and 11. The control unit 23 can control the reception process based on the downlink SPS in FIGS. 3 to 4 and 14. The control unit 23 can control the reception process of the transmission parameter notification in FIG. The control unit 23 can control the UL Grant reception process in FIG. The control unit 23 can control the reception process of the transmission end notification in FIG. The control unit 23 can control the DCI reception process in FIG. The control unit 23 can control the reception process of the downlink data transmission in FIG. The control unit 23 can control the reception process of the extended response in FIGS. 15 and 17. The control unit 23 can control the transmission process based on the uplink SPS in FIGS. 1 to 2, 7, 11, 13 and 15 to 17. The control unit 23 can control the transmission process of the uplink transmission in FIGS. 5 to 6. The control unit 23 can control the transmission process of the transmission end notification in FIGS. 12 to 13. The control unit 23 can control the transmission process of the upstream data transmission in FIG. The control unit 23 can control the transmission process of the extension request in FIGS. 15 and 17.

[Hardware configuration of each device in the wireless communication system of each embodiment]
The hardware configuration of each device in the wireless communication system of each embodiment and each modification will be described with reference to FIGS. 21 to 22.

FIG. 21 is a diagram showing a hardware configuration of the radio base station 10. As shown in FIG. 21, the radio base station 10 has, as hardware components, for example, an RF (Radio Frequency) circuit 32 including an antenna 31, a CPU (Central Processing Unit) 33, and a DSP (Digital Signal Processor) 34. And a memory 35 and a network IF (Interface) 36. The CPU is connected so that various signals and data can be input and output via the bus. The memory 35 includes at least one of a RAM (Random Access Memory) such as an SDRAM (Synchronous Dynamic Random Access Memory), a ROM (Read Only Memory), and a flash memory, and stores programs, control information, and data.

The correspondence between the functional configuration of the radio base station 10 shown in FIG. 19 and the hardware configuration of the radio base station 10 shown in FIG. 21 will be described. The transmitting unit 11 and the receiving unit 12 (or the communication unit 14) are realized by, for example, an RF circuit 32, or an antenna 31 and an RF circuit 32. The control unit 13 is realized by, for example, a CPU 33, a DSP 34, a memory 35, a digital electronic circuit (not shown), or the like. Examples of the digital electronic circuit include an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programming Gate Array), an LSI (LargeScale Integration), and the like.

FIG. 22 is a diagram showing a hardware configuration of the wireless terminal 20. As shown in FIG. 22, the wireless terminal 20 has, for example, an RF circuit 42 including an antenna 41, a CPU 43, and a memory 44 as hardware components. Further, the wireless terminal 20 may have a display device such as an LCD (Liquid Crystal Display) connected to the CPU 43. The memory 44 includes at least one of RAM such as SDRAM, ROM, and flash memory, and stores programs, control information, and data.

The correspondence between the functional configuration of the wireless terminal 20 shown in FIG. 20 and the hardware configuration of the wireless terminal 20 shown in FIG. 22 will be described. The transmitting unit 21 and the receiving unit 22 (or the communication unit 24) are realized by, for example, an RF circuit 42, or an antenna 41 and an RF circuit 42. The control unit 23 is realized by, for example, a CPU 43, a memory 44, a digital electronic circuit (not shown), or the like. Examples of the digital electronic circuit include ASIC, FPGA, LSI and the like.

1 Wireless communication system 2 Network 3 Network device 10 Wireless base station C10 Cell 20 Wireless terminal

Claims (18)

A receiving unit that receives first information including bitmap information corresponding to the communication interval in communication performed at a communication interval consisting of a plurality of sections from a radio base station.
Based on the first information, the radio base station and the communication unit that performs the communication are provided.
The bitmap information is in the communication distance, it viewed including the second information indicating a transmittable predetermined number of intervals,
The predetermined transmittable sections correspond to the presence or absence of allocation of radio resources indicated by each bit among the sections corresponding to each bit in the bitmap.
Wireless terminal. The communication unit transmits / receives signals based on different data in each of the predetermined sections.
The wireless terminal according to claim 1. The communication is transmission
The first or second aspect of claim 1 or 2, wherein when the communication unit does not perform the transmission in the remaining section of the predetermined section after a certain section, the communication unit notifies the radio base station of the end of transmission. Wireless terminal. The wireless terminal according to claim 3, wherein the wireless base station allocates wireless resources for the transmission in at least a part of the remaining sections to other wireless terminals when notified of the end of transmission. The wireless terminal according to claim 4, wherein at least a part of the remaining section is a section excluding a section corresponding to a period required for the other wireless terminal to transmit data in the remaining section. The wireless terminal according to claim 3, wherein the communication unit does not notify the end of transmission when the remaining section is less than the section corresponding to the period required for the other wireless terminal to transmit data. The wireless terminal according to claim 3, wherein the communication unit notifies the end of transmission by using the wireless resource for the transmission. The wireless terminal according to any one of claims 1 to 7, wherein the predetermined number of sections includes a plurality of discontinuous sections included in the communication interval. A transmission unit that transmits the first information including the bitmap information corresponding to the communication interval in the communication performed at the communication interval consisting of a plurality of sections to the wireless terminal.
Based on the first information, the wireless terminal and the communication unit that performs the communication are provided.
The bitmap information is in the communication distance, viewed including the second information indicating a transmittable predetermined number of intervals, the transmittable predetermined number of intervals, of the interval corresponding to each bit in the bitmap, Depending on whether or not the radio resource is allocated, which is indicated by each of the above bits.
Radio base station. The communication unit transmits / receives signals based on different data in each of the predetermined sections.
The radio base station according to claim 9. The communication is reception
A claim that the communication unit receives a notification of the end of transmission from the wireless terminal when the wireless terminal does not perform transmission corresponding to the reception in the remaining section of the predetermined section after a certain section. The radio base station according to 9 or 10. The radio according to claim 11, wherein when the communication unit receives the notification of the end of transmission, the communication unit transmits information for allocating the radio resource for the transmission in at least a part of the remaining section to another radio terminal. base station. The radio base station according to claim 12, wherein at least a part of the remaining section is a section excluding a section corresponding to a period required for the other radio terminal to transmit data in the remaining section. The wireless base station according to claim 11, wherein the wireless terminal does not notify the end of transmission when the remaining section is less than a section corresponding to a period required for another wireless terminal to transmit data. The radio base station according to claim 11, wherein the communication unit receives the notification of the end of transmission by using the radio resource for the transmission. The radio base station according to any one of claims 9 to 15, wherein the predetermined number of sections includes a plurality of discontinuous sections included in the communication interval. With wireless terminals
A wireless base station that transmits first information including bitmap information corresponding to the communication interval in communication performed at a communication interval consisting of a plurality of sections to the wireless terminal, and
It is a wireless communication system equipped with
The wireless terminal performs the communication with the wireless base station based on the first information.
The bitmap information is in the communication distance, viewed including the second information indicating a transmittable predetermined number of intervals, the transmittable predetermined number of intervals, of the interval corresponding to each bit in the bitmap, Depending on whether or not the radio resource is allocated, which is indicated by each of the above bits.
Wireless communication system. The radio base station transmits the first information including the bitmap information corresponding to the communication interval in the communication performed at the communication interval consisting of a plurality of sections to the wireless terminal.
A wireless communication method in which the wireless terminal performs the communication with the wireless base station based on the first information.
The bitmap information is in the communication distance, it viewed including the second information indicating a transmittable predetermined number of intervals,
The predetermined transmittable sections correspond to the presence or absence of allocation of radio resources indicated by each bit among the sections corresponding to each bit in the bitmap.
Wireless communication method.