WO2010102564A1

WO2010102564A1 - Base station

Info

Publication number: WO2010102564A1
Application number: PCT/CN2010/070953
Authority: WO
Inventors: 张元涛; 周华; 田军; 王键
Original assignee: 富士通株式会社
Priority date: 2009-03-13
Filing date: 2010-03-10
Publication date: 2010-09-16
Also published as: CN101835194B; CN101835194A

Abstract

A base station and a method for communication between the base station and a relay station are provided by the invention. The base station comprises a transmission unit (604), a reception unit (602), a decision unit (603) and a scheduling unit (604), wherein said decision unit (603) is used for determining whether the relay station has signals to be transmitted to the base station; the scheduling unit (604) schedules the reception unit (602) according to the determining result of the decision unit 603, thus when said relay station has signals to be transmitted to the base station, it makes said reception unit (602) receive data from said relay station in the periods for one or more uplink subframes, which are regarded as uplink relay link subframes, except the uplink subframes for transmitting reception response to data which are transmitted in absolute downlink access link subframes, and said scheduling unit also schedules mobile stations, thus said mobile stations don't send data to said relay station in said periods for uplink relay link subframes.

Description

Base station

Technical field

The present invention relates to communication systems, and more particularly to communication systems including transparent relay stations. Background technique

With the rapid development of wireless multimedia services, users are increasingly demanding data communication capabilities and transmission quality. However, due to the effects of blocking, shadowing, etc. in a complex wireless environment, many communication dead ends are formed. These will make it difficult for users to obtain sustained high-speed and high-quality communication services. To solve this problem, the wireless system uses a relay station to forward wireless communication signals between the base station and the mobile station to increase system throughput and user data rate.

In a wireless communication system including a relay station, the mobile stations can be classified into two types according to the direct communication target of the mobile station, which are a mobile station served by the base station and a mobile station served by the relay station. Figure 1 shows the data forwarding process for a typical relay station. As shown in FIG. 1, UE 1 and UE 2 are mobile stations served by the relay station, and UE 3 is a mobile station served by the base station. UE 1 and UE 2 first transmit data to the relay station RS (relay station reception), and then the RS transmits the collected data (UE 1 data and UE 2 data) to the base station BS (neutral station forwarding). It should be noted that only the relay station RS collects data from the mobile stations served by the relay station and forwards the data to the base station, and the relay station can also receive data from the base station and forward the data to the mobile station served by the relay station. In addition, the number of UEs is also illustrative.

It is generally required that the addition of a relay station in a wireless system does not have any impact on the existing mobile station specification, that is, the relay station is transparent to the mobile station, and the mobile station does not know the existence of the relay station. Generally, a communication link between a base station and a relay station is referred to as a relay link, and a link between a base station or a relay station and a mobile station is referred to as an access link. The communication link from the base station to the relay station is referred to as a downlink relay link, and the communication link from the relay station to the base station is referred to as an uplink relay link; the communication link of the base station or the relay station to the mobile station is referred to as a downlink connection. Incoming link, the communication link from the mobile station to the relay station or base station is called the uplink access link.

In the process of making the present invention, the inventors found that in the TDD system, when a trunk is introduced, there is a collision problem between ACK/NACK feedback and transmitted data. This will be explained below.

In the TDD system, the added relay station has only one RF link, so at a certain time, the relay station can only be in the receiving state or the transmitting state, and cannot be in the transmitting and receiving state at the same time. In the TDD system, the relay station cannot be in the transmitting and receiving state at the same time. Therefore, in the downlink relay link, the relay station is in the receiving state, so the relay station cannot transmit any data to the mobile station at this time; in the uplink relay link, the relay station is in the transmitting state. State, the relay station cannot receive signals from the mobile station.

The following is a brief description of the frame structure of the existing LTE TDD standard. In LTE TDD, one frame is fixed to 10ms and contains 10 1ms subframes. According to the number of uplink subframes and downlink subframes, LTE TDD defines seven frame structures, that is, frame structure 0-6. Some subframes in a 10ms frame are allocated to the downlink, which is called a downlink subframe, and some subframes are assigned to the uplink, which is called an uplink subframe. The base station transmits data in a downlink subframe, and the mobile station or relay station receives data; the mobile station transmits data in an uplink subframe, and the relay station or base station receives data. The following takes an example of Fig. 2 for explanation. 2 is a frame structure 3 of LTE TDD, where D represents a downlink subframe, and subframes #0 and #5-#9 in the figure are downlink subframes. S represents a special subframe, which is subframe #1. Subframe #1 is used for the base station to transmit the peer signal, the mobile station to transmit the access signal, and the transmission and reception of the mobile station and the base station. U denotes an uplink subframe, which is subframes #2, #3, #4. If the downlink subframe #9 is used for the data link of the base station to the relay station, the subframe #9 is referred to as a downlink relay link subframe, and the other downlink subframes are referred to as downlink access link subframes. If uplink subframe #2 is used for the data link of the relay station to the base station, subframe #2 is referred to as an uplink relay link subframe, and other uplink subframes are referred to as uplink access link subframes.

For the downlink, the downlink relay link subframe may be configured as a Broadcast Multicast Single Frequency Network (MBSFN) subframe for transmitting data from the base station to the relay station. The time-frequency structure of a typical MBSFN subframe is shown in Figure 3. As shown, wherein all mobile stations receive control signaling, pilot symbols, and the like from a base station or a relay station in the first or two OFDM symbols of the MBSFN subframe, and the following OFDM symbols are invisible to all mobile stations. Therefore, the OFDM symbol following the MBSFN subframe can be used to transmit the data signal of the base station to the relay station.

Since the broadcast channel, the addressed channel, the peer channel, and the like need to be transmitted in the downlink subframe or the special subframe #0, #1, #5, #6, these four subframes cannot be used as the MBSFN subframe, and can only be used as the MBSFN subframe. The downlink access link subframe is used herein. For the convenience of description, the subframe that can only be used as the downlink access link subframe is referred to as an absolute downlink access link subframe.

After receiving the data transmitted by the base station or the relay station, the mobile station needs to send a decoding response signal ACK/NACK (also referred to herein as reception feedback) to the base station and the relay station, where ACK indicates that the correct signal is decoded, and NACK indicates that the decoding is incorrect. signal. In order to have no impact on the existing LTE TDD standards after joining the relay station, the ACK/NACK feedback must follow the existing LTE TDD standard. The delay between the feedback from receiving data to ACK/NACK is required in the existing standard to be greater than 3ms. Taking FIG. 4 as an example, the third behavior is a fixed ACK/NACK feedback position corresponding to the data transmitted in each subframe. As shown in FIG. 4, the ACK/NACK for the data transmitted in the downlink subframe #0 must be fed back in the subframe #4, and the ACK/NACK of the data transmitted for the uplink subframe #2 must be fed back in the subframe #8. It should be noted that in which subframe the ACK/NACK feedback is specified in the standard, it is generally not changed.

Since subframes #0, #1, #5, and #6 cannot be used as MBSFN subframes, that is, downlink relay link subframes, these subframes can only be used for the base station to transmit data to the mobile station or the relay station to the mobile station. data. The ACK/NACK generated after the mobile station receives the data must be sent in the corresponding fixed uplink subframe. If these uplink subframes are used for the uplink relay link, since the relay station is in the transmission state of the uplink relay link, the relay station will not be able to receive the ACK/NACK from the mobile station, that is, a collision occurs. The generation of such a collision is illustrated by using FIG. 4 as an example. In FIG. 4, subframe #2 is an uplink relay link subframe, that is, data is transmitted from the RS to the BS. Subframe #9 is an MBSFN subframe, that is, a downlink relay link subframe. In the subframe #2 of the next frame, the mobile station feeds back the ACK/NACK corresponding to the data transmitted by the relay station in the subframes #5 and #6 to the relay station, but since the subframe #2 has already been used as the uplink relay link at this time, That is, the relay station is in the transmission state, so the relay station will not be able to receive the ACK/NACK fed back by the mobile station serving the relay station. That is, a collision of ACK/NACK and transmitted data occurs.

For the collision problem between the above ACK/NACK feedback and the transmitted data, a specific solution has not been given in the LTE TDD standard.

Receive feedback (ACK/NACK) from the mobile station can be transmitted by the base station or the relay station in the MBSFN subframe. In some cases, there may also be a collision between the relay station transmitting an ACK/NACK to the mobile station and receiving data from the base station.

It should be noted that the above description of the conventional technology is only for the purpose of facilitating the clear and complete description of the technical solutions of the present invention and is convenient for the understanding of those skilled in the art. The above technical solutions are not considered to be well known to those skilled in the art simply because these solutions are described in the background section of the present invention.

The following is a list of references to the present invention, which are hereby incorporated by reference inso-

1. [Special Wo[I Literature 1]: Tak-ki Yu, et al, Method and apparatus for allocating peer-to-peer resource in relay based wireless communication system (US 20090034447 Al);

2, [Specialty ll literature 2]: Jeffrey D. Bonta, et al "System and method of resource allocation within a communication system (US 20090034432 Al);

3, [Specialty ll Document 3]: Relay system and method for bandwidth allocation and Scheduling (US 20080316954 Al) _;

4, [Specialty ll literature 4]: Radio resource management in wireless cellular networks having multihop relay stations (US 20080220790 Al);

5. [Special radio resource sharing in time and frequency domains among TDD communication systems (US 20080144612 Al);

5. [Non-Patent Document 1] : Nokia, Considerations on TDD Relay, 3GPP TSG-RAN1, Rl-090244;

6. [Non-specialized ll document 2]: LG, UL subframe stealing for in-band relaying in TDD mode, 3GPP TSG-RANl, Rl-090225. Summary of the invention

Embodiments of the present invention have been made in view of the foregoing problems of the prior art for solving or alleviating the problem of ACK/NACK and data collision (hereinafter referred to as ACK/NACK collision).

In order to achieve the above object, the present invention provides the following aspects:

Aspect 1, a base station, the base station includes a transmitting unit, a receiving unit, a determining unit, and a scheduling unit, wherein the determining unit is configured to determine whether the relay station has a signal to be sent to the base station; and the scheduling unit determines, according to the judgment result of the determining unit, The receiving unit performs scheduling, so that when the relay station has a signal to be sent to the base station, the receiving unit is used as an uplink relay link subframe for transmitting on an absolute downlink access link subframe. Receiving the signal from the relay station during one or more uplink subframes other than the uplink subframe of the received feedback of the data, and the scheduling unit further scheduling the mobile station and the relay station, thereby The mobile station does not transmit data to the relay station during the uplink relay link subframe.

The base station according to aspect 1, wherein the determining unit is configured to determine the Whether the base station has a signal to be sent to the relay station; the scheduling unit schedules the transmitting unit according to the judgment result of the determining unit, so that when the base station has a signal to be sent to the relay station, the transmitting unit is caused to be in the downlink Sending, by the relay link subframe, the received feedback to the relay station during the one or more downlink subframes transmitted on the subframe corresponding to the uplink relay link subframe, Notifying the mobile station: the downlink subframe as the downlink relay link subframe is an MBSFN subframe, and the scheduling unit schedules the relay station, so that the relay station is No data is transmitted to the mobile station during the downlink relay link subframe.

Aspect 3. The base station according to aspect 1, characterized in that the signal to be transmitted by the relay station to the base station comprises a data signal to be transmitted to the base station and a reception feedback signal to be transmitted to the base station.

Aspect 4. The base station according to aspect 2, characterized in that the signal to be transmitted by the base station to the relay station comprises a data signal to be transmitted to the relay station and a reception feedback signal to be transmitted to the relay station.

Aspect 5: The base station according to aspect 1, wherein the scheduling unit further performs scheduling, so that when the relay station has a signal to be sent to the base station, the receiving unit is configured as a specific subframe. Receiving the signal from the relay station in a downlink subframe other than the absolute downlink access link subframe, and the scheduling unit notifying the relay station: in a downlink corresponding to the specific subframe The signal is sent in the link subframe, and the scheduling unit notifies the mobile station that the downlink subframe corresponding to the specific subframe is an MBSFN subframe.

Aspect 6. The base station according to aspect 5, wherein the specific subframe includes a period in which the base station transmits a signal to the mobile station.

Aspect 7. The base station according to aspect 6, wherein the specific subframe includes a transition period for converting the base station from a transmitting state to a receiving state and/or rotating the base station from a receiving state. Switch to the transition period of the sending status.

Aspect 8. The base station according to aspect 6, wherein the base station further includes an adjustment unit, where the adjustment unit is configured to adjust a duration of the base station in the receiving state in the specific subframe.

Aspect 9. The base station according to aspect 7, wherein the adjusting unit further adjusts a transition period for converting the base station from a transmitting state to a receiving state and/or converting the base station from a receiving state to a transmitting state. The length of the conversion period.

Aspect 10: A base station, where the base station includes a sending unit, a receiving unit, a determining unit, and a scheduling unit, where

The determining unit is configured to determine whether the relay station has a signal to be sent to the base station;

The scheduling unit schedules the receiving unit according to the judgment result of the determining unit, so as to receive the signal from the relay station in a downlink subframe other than the absolute downlink access link subframe as a specific subframe, And the scheduling unit notifying the relay station that: the signal is sent in a downlink subframe corresponding to the specific subframe, and the scheduling unit notifies the mobile station: corresponding to the specific subframe The downlink subframe is an MBSFN subframe.

Aspect 11. A scheduling method includes the following steps: determining, determining, by a base station, whether data is sent to a relay station, and scheduling a step, and when determining, by the determining step, that there is data sent to the relay station, In a downlink subframe, the base station sends data to the relay station, notifying the mobile station that the downlink subframe is an MBSFN subframe; and scheduling, so that the mobile station is not transmitting the subframe for feedback of the data transmitted by the downlink subframe. Transfer data to the relay station.

Aspect 12: A scheduling method includes the following steps: determining a step, determining whether a relay station has data to be sent to a base station, and scheduling a step, and when determining that the relay station has data to be transmitted to the base station, optionally selecting a certain uplink The frame is used as an uplink relay link subframe, and the scheduling is performed so that the relay station does not send downlink data to the mobile station in the subframe in which the feedback information is carried in the uplink subframe, and is scheduled to make the mobile station not The uplink data is transmitted to the relay station during the uplink subframe.

Aspect 13. The scheduling method according to aspect 12, further comprising the step of: scheduling the relay station to cause the relay station not to transmit a signal to the mobile station in a downlink subframe carrying feedback of data transmitted in the uplink subframe.

Aspect 14, a base station, the base station includes a transmitting unit, a receiving unit, a determining unit, and a scheduling unit, wherein the determining unit is configured to determine whether the relay station has a signal to be sent to the base station, and whether the base station has to send to the base station a signal of the relay station; the scheduling unit performs scheduling according to the judgment result of the judgment unit, thereby (1) when the relay station has a signal to be transmitted to the base station and the base station has a signal to be transmitted to the relay station, And causing the receiving unit to perform one or more uplinks other than an uplink subframe for receiving feedback of data transmitted on an absolute downlink access link subframe as an uplink relay link subframe Receiving a signal from the relay station during a subframe, and the scheduling unit further scheduling the mobile station and the relay station, so that the mobile station does not transmit data to the relay station during the uplink relay link subframe, And causing the sending unit to transmit the feedback on the uplink relay link subframe as a downlink relay link subframe Transmitting the data to the relay station during one or more downlink subframes, the scheduling unit notifying the mobile station that: the downlink subframe corresponding to the downlink relay link subframe is MBSFN subframe, and the scheduling unit schedules the relay station, so that the relay station does not transmit data to the mobile station during the downlink relay link subframe; or at the relay station, there is to be sent to the base station And when the base station has a signal to be transmitted to the relay station, receiving data from the relay station in a downlink subframe other than the absolute downlink access link subframe as a specific subframe, and The scheduling unit notifies the relay station: transmitting uplink data in a downlink subframe corresponding to the specific subframe; (2) determining, in the determining step, that the base station has a signal sent to the relay station However, when the relay station does not send a signal to the base station, in a certain downlink subframe, the base station sends a signal to the relay station, and the notification is shifted. The downlink subframe is an MBSFN subframe; and scheduling is performed, so that the mobile station does not transmit data to the relay station during a subframe that transmits feedback for the data transmitted by the downlink subframe; (3) determining that the relay station is to be transmitted to When the data of the base station is selected, an uplink subframe is selected as an uplink relay link subframe, and scheduling is performed so that the relay station does not send downlink data to the mobile station in a subframe in which the feedback information is carried in the uplink subframe, and The scheduling is performed such that the mobile station does not transmit uplink data to the relay station during the uplink subframe.

These and further aspects and features of the present invention will become more apparent from the description and appended claims. The detailed description of the preferred embodiments of the invention are in the It should be understood that the invention is not limited in scope thereby. The invention includes many modifications, adaptations and equivalents within the scope of the spirit and scope of the appended claims.

Features described and/or illustrated with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, in combination with, or in place of, features in other embodiments. .

It should be emphasized that the term "comprising" or "comprises" or "comprises" or "comprising" or "comprising" or "comprising" or "comprising" or "comprising" or "comprising" or "comprising" or "comprising" or "comprising" or "comprising" or "comprising"

Many aspects of the invention can be better understood with reference to the following drawings. The components in the figures are not drawn to scale, but only to illustrate the principles of the invention. To facilitate the illustration and description of some parts of the invention, the corresponding parts of the drawings may be enlarged, i.e., made larger relative to other components in an exemplary apparatus actually fabricated in accordance with the present invention. Elements and features described in one of the figures or one embodiment of the invention may be combined with elements and features illustrated in one or more other figures or embodiments. In the accompanying drawings, like reference numerals refer to the DRAWINGS The drawings illustrate the preferred embodiments of the invention, and are in the among them:

Figure 1 shows the data forwarding process of a typical relay station system;

2 shows the configuration of the LTE TDD system frame structure 3 and the selected uplink and downlink relay link subframes;

Figure 3 shows the time-frequency structure of the MBSFN subframe;

4 shows an LTE TDD system frame structure 3, illustrating a collision problem of ACK/NACK; FIG. 5 schematically shows a frame structure 3 according to a first embodiment of the present invention;

6 is a schematic structural diagram of a base station according to a first embodiment of the present invention;

Fig. 7 is a view schematically showing the processing in the base station BS shown in Fig. 6 in the case where the frame structure 3 shown in Fig. 5 is employed;

FIG. 8 is a view schematically showing an operation timing chart of a communication system according to an embodiment of the present invention; FIG.

Figure 9 is a schematic illustration of the structure of a particular subframe of an embodiment;

Figure 10 is a schematic illustration of a frame structure 3 in accordance with a second embodiment of the present invention;

Figure 11 is a schematic illustration of another frame structure 3 in accordance with a second embodiment of the present invention;

FIG. 12 shows a scheduling for solving the ACK/NACK collision problem when there is no TDD frame structure shown in FIG. 5, when there is no data communication relayed to the base station;

FIG. 13 is a diagram showing the scheduling of the ACK/NACK collision problem when there is no data transmission from the base station to the relay when there is no base station to relay data communication for the TDD frame structure 3 shown in FIG. 5;

14 shows, for the TDD frame structure 3 shown in FIG. 5, there is a data communication between the relay station and the base station in a certain 10 ms frame, and there is no scheduling of the ACK/NACK collision problem when there is no data communication from the base station to the relay station; FIG. 15 is a diagram showing the TDD frame structure 3 of the second embodiment, where there is a data communication relayed to the base station in a certain 10 ms frame, and there is no scheduling of the ACK/NACK collision problem when there is no data communication from the base station to the relay station;

16 shows, according to an embodiment of the present invention, for a LTE TDD frame structure 3, a 10 ms frame has a base station to a relay station data communication, and there is no relay station to base station data communication, in order to solve the ACK/NACK collision problem Scheduling

FIG. 17 illustrates a data communication between a relay station and a base station in a certain 10 ms frame for a LTE TDD frame structure 3, and a scheduling used to solve an ACK/NACK collision problem when there is no data communication from a base station to a relay station according to an embodiment of the present invention. ;

18 shows an LTE TDD frame structure 3, a data communication between a relay station and a base station in a 10 ms frame, and a scheduling method used to solve an ACK/NACK collision problem when there is no data communication from the base station to the relay station;

Fig. 19 is a flow chart schematically showing a scheduling method of another embodiment of the present invention. detailed description

Hereinafter, a method and an apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings, taking a general communication system including a relay station as an example.

First embodiment

In a first embodiment in accordance with the invention, the base station will not transmit uplinks for feedback of data transmitted on absolute downlink access link subframes (e.g., subframes #0, #1, #5, #6) The subframe is set as an uplink relay link subframe. And setting the downlink access link subframe transmitted on the set uplink relay link subframe to the downlink in the ACK/NACK feedback for the data transmitted on the downlink access link subframe. Following the link subframe, that is, the MBSFN subframe. Fig. 5 schematically shows a frame structure 3 according to a first embodiment of the invention.

As shown in FIG. 5, there are three uplink subframes in the frame structure 3, that is, subframes #2, #3, and #4. Subframe #2 needs to transmit ACK/NACK feedback for data transmitted on the absolute downlink access link subframe (subframe #5, #6), and thus subframe #2 should not be set as the uplink relay link Subframe. Similarly, subframe #4 is to transmit ACK/NACK feedback of data transmitted on the absolute downlink access link subframe (subframe #0), and thus subframe #4 should not be set as the uplink relay link. frame. Thus, subframe #3 is set as an uplink relay link subframe.

There are three non-absolute downlink subframes in frame structure 3, namely subframes #7, #8, #9. ACK/NACK feedback for data transmitted on subframe #9 is transmitted on subframe #4, and ACK/NACK feedback for data transmitted on subframes #7 and #8 is in subframe #3 (also called uplink) The subframe corresponding to the relay link subframe is transmitted on the corresponding subframe of the other frame. Thus, subframes #7 and #8 are both set as downlink relay link subframes.

In the example shown in FIG. 5, ACK/NACK feedback for the transmitted data on subframes #5 and #6 is transmitted in subframe #2, and subframe #2 is not used as an uplink relay link. At this time, the relay station is in the receiving state and will not cause an ACK/NACK collision. Similarly, since subframe 7 and subframe 8 are all used as MBSFN subframes for transmitting BS-to-RS data and ACK/NACK information, the mobile station does not generate ACK/NACK feedback, so it does not change due to subframe #3. It becomes an uplink relay link and causes an ACK/NACK collision.

FIG. 6 is a schematic structural diagram of a base station according to a first embodiment of the present invention. As shown in FIG. 6, the base station according to the first embodiment of the present invention includes a transmitting unit 601, a receiving unit 602, a judging unit 603, and a scheduling unit 604.

The transmitting unit 601 is configured to send various data, control commands, pilot signals, and the like to the mobile station served by the relay station or the base station, and the receiving unit 602 is configured to receive various numbers from the mobile station directly served by the relay station or the base station. According to, feedback, etc. The base station sends control signaling and pilot to the relay station and the mobile station in one or two OFDM symbols preceding each downlink subframe, where the control signaling includes scheduling information of the base station, that is, notifying the mobile station or the relay station Which time-frequency unit of the frame receives the data, and notifies the mobile station and the relay station which time-frequency unit of which uplink subframe transmits data or the like to the base station. The control signaling also includes an ACK/NACK fed back to the mobile station or relay after the base station receives the data of the mobile station or the relay.

The judging unit 603 is for judging whether the base station has data to be transmitted to the relay station, and judging whether the relay station has data to be transmitted to the base station.

The scheduling unit 604 schedules the relay station and the mobile station based on the judgment result of the judgment unit 603. In a first embodiment of the invention, the transmitting unit does not need to transmit uplinks for feedback of data transmitted on absolute downlink access link subframes (e.g., subframes #0, #1, #5, #6) The sub-frame (ie, the set uplink relay link subframe) receives data, ACK/NACK, and the like from the relay station. And transmitting ACK/NACK feedback for the data transmitted thereon in the downlink access link subframe to the relay station during the downlink access link subframe transmitted on the set uplink relay link subframe Downlink data, ACK/NACK, etc.

Fig. 7 shows the processing in the base station BS shown in Fig. 6 in the case where the frame structure 3 shown in Fig. 5 is employed.

First, the determination unit 603 of the base station determines whether the base station is to transmit data to the relay station and determines whether the relay station is to transmit a signal to the base station (S700). If the base station wants to send a signal to the relay station and the relay station wants to send a signal to the base station (S701, YES), then in step S704, the scheduling unit 604 of the base station performs scheduling so that the mobile station is in the uplink relay link subframe (subframe 3) Not transmitting the uplink data, and causing the relay station not to transmit the signal to the mobile station in the downlink relay link subframe (subframe 8) (scheduling 1), and in step S705, causing the transmitting unit 601 to determine the downlink trunk chain The signal transmitted to the relay station on the road, and the receiving unit 602 receives the signal from the relay station on the determined uplink relay link in step S706. If the base station has a signal to If the relay station transmits to the relay station but there is no signal to be transmitted to the base station (S702, YES), since the relay station is in the receiving state in the subframe #7 or #8, in order to avoid collision, the scheduling unit 604 of the base station performs the processing in step S707. Scheduling (scheduling 2), causing the relay station not to transmit data to the mobile station in the subframe (subframe #7 or #8), notifying the mobile station that the subframe is an MBSFN subframe, and in step S708, in the MBSFN sub A signal is sent to the relay station in the frame. If the base station has no signal to transmit to the relay station but the relay station has a signal to transmit to the base station (S703, YES), since the relay station is in the transmitting state in the subframe, the scheduling unit 604 of the base station performs scheduling to enable the mobile station to relay in the uplink. The link subframe (subframe #3) does not transmit an uplink signal (S709), and then receives a signal from the relay station in the uplink relay link subframe (S710). If the base station has no signal to transmit to the relay station and the relay station has no signal to transmit to the base station, the scheduling unit 604 of the base station performs the same conventional scheduling as the prior art without special scheduling (S711).

The determining unit 603 of the base station can decide whether or not to transmit data to the relay station based on the amount of data that can be transmitted in one downlink relay link subframe and the data that needs to be transmitted to the relay station stored at the base station. Specifically, for example, when the amount of data stored is greater than the amount of data that can be transmitted by one downlink relay link subframe, the base station can schedule data transmission to the relay station.

Similarly, the determining unit 603 of the base station judges whether the relay station has data to be transmitted thereto according to the amount of data that can be transmitted in one uplink relay link subframe and the amount of data received at the relay station monitored by the base station. Specifically, for example, when the amount of data received by the relay station is larger than the amount of data that can be transmitted by one uplink relay link subframe, it can be judged that the relay station needs to transmit data thereto.

Whether the mobile station transmits data to the base station or the relay in an uplink subframe is determined by control signaling sent by a corresponding downlink subframe, and if the base station allows the mobile station to transmit data in an uplink subframe, The base station sends control signaling to the mobile station in the first two or three OFDM symbols of the corresponding downlink subframe, indicating whether it is allowed to send data in the uplink subframe, and indicating the time-frequency resource occupied by the transmission data. Wait. Fig. 8 is a view schematically showing an operation timing chart of a communication system of an embodiment of the present invention.

In one frame, the transmitting unit of the base station transmits the pilot to the mobile station served by the base station in the previous one or two OFDM symbols in the MBSFN subframe (subframe #7 or #8) which is the downlink relay link subframe. And information such as control signaling (S100), the relay station transmits information such as pilot and control signaling to the mobile station served by the relay station in the first few OFDM symbols in the MBSFN subframe (S110).

The base station transmits information to the relay station in the subsequent OFDM symbol (S120). The relay station receives information transmitted from the base station in subsequent OFDM symbols.

The mobile station receives information such as pilot or control signaling from the base station or the relay station in the first few OFDM symbols in the MBSFN subframe, and does not receive any information at other times.

Meanwhile, in the uplink relay link subframe #3, the base station receives the information transmitted from the relay station; the relay station transmits the information to the base station (S130); for all the mobile stations, under the scheduling of the base station, remains in the uplink subframe silence.

It should be noted that the diagram of Fig. 8 is schematic, and the processing of the base station, the relay station, and the mobile station in other subframes is omitted to more clearly illustrate the features of the embodiments of the present invention.

As can be seen from the above description, the frame structure followed by the mobile station is completely unchanged, so that the mobile station does not need to make any changes.

Second embodiment

In the second embodiment of the present invention, the base station changes a certain downlink access link subframe into a specific subframe, and the specific subframe is used as an MBSFN subframe for all mobile stations, and receives control signals from the base station and the relay station. The relay station is used as a specific subframe for transmitting control signaling to the mobile station serving the relay station and for transmitting data to the base station. For the base station to be used as a specific subframe, the mobile station for serving the base station transmits control signaling and is used to receive data transmitted by the relay station.

Figure 9 schematically illustrates the structure of a particular subframe of an embodiment. As shown in Figure 9, for the office In some UEs, the subframe is represented as MBSFN. That is, in the previous or two OFDM symbols, the BS and the RS respectively send control signaling and pilots, etc., to the respective serving users, and the BS is in the transmitting state. For convenience of explanation, the time when the BS is in the transmission state in the specific subframe is the downlink period. In the next short period of time (the base station determines the length of this period of time), the BS changes from the transmitting state to the receiving state. This period of time may be referred to as a first transition period or a first guard period, or may not be there. The BS then receives the forwarding data from the RS for the next time, which is referred to as the uplink period. Here, in this time slot, if the base station has ACK/NACK feedback to be transmitted to the relay station, the ACK/NACK feedback may be multiplexed with the data of the base station to the relay station. Finally, the BS changes from the receiving state to the transmitting state, and the period of time may be referred to as a second switching period or a second guard period, or may not have the period.

In addition, although in the example shown in Fig. 9, the transmission period transmits only control signaling, pilots, etc., in an alternative embodiment, BS to RS data may also be transmitted in some symbols.

Fig. 10 schematically shows a frame structure 3 in accordance with a second embodiment of the present invention. As shown in FIG. 10, the non-absolute downlink subframe #7 in the downlink subframe is configured as a specific subframe, and another non-absolute downlink carrying the feedback information for the data transmitted on the specific subframe will be carried. A sub-frame, such as subframe #8 or #9 (shown as subframe #9 in the example of Fig. 10), is set as an MBSFN subframe. At the same time, the scheduling unit of the base station notifies the mobile station that the two subframes (#7 and #9) are MBSFN subframes, and informs the relay station that the subframe 7 is a specific subframe, and the subframe 9 is an MBSFN subframe. It should be noted that the foregoing description is merely exemplary, and other subframes, such as an absolute downlink subframe, may also be set as a specific subframe. Similarly, an absolute downlink subframe can also be set to carry a feedback subframe for feedback of data transmitted on that particular subframe.

In addition, it should be noted that although in the example of FIG. 10, subframe #9 is used as a downlink relay link subframe, it is also possible to configure subframe 7 only as a specific subframe without additionally setting other downlink relay chains. Road subframe (a specific subframe transmits both BS to RS data and RS to BS data). In addition, although In the example of FIG. 10, the subframe 7 is configured as a specific subframe, but other subframes (for example, subframe 8 and subframe 9) may be set as a specific subframe. In addition, multiple specific subframes can be set.

When there is data communication from the relay station to the base station in a 10ms frame, the data is first sent to the BS in the specific subframe #7, RS. After receiving the data, the BS transmits feedback on the received data in subframe #9 of the next frame. Since subframe #7 and subframe #9 are both downlink subframes for the mobile station, no ACK/NACK collision occurs. Similarly, in a 10ms frame, when the base station has data communication to the relay station, it transmits in subframe #9, and the feedback of the RS on the received data can be transmitted in subframe #7 of the next frame. Since subframe #7 and subframe #9 are both downlink subframes for the mobile station, ACK/NACK collision does not occur.

In addition, in the case where an additional MBSFN is not set except for a specific subframe, the feedback of the specific subframe can be set as the specific subframe itself. This is shown, for example, in Figure 11. At this time, it is only necessary to notify the mobile station that the subframe #7 is an MBSFN subframe.

Thus, in the second embodiment of the present invention, the frame structure followed by the mobile station does not change, although the frame structure between the relay station and the base station and the frame structure between the base station and the mobile station and the frame between the relay station and the mobile station The structure is different, but the agreement between the base station and the relay station is relatively easy to implement.

In the second embodiment, the transmitting unit 601 of the base station is configured to send various data, control commands, pilot signals, and the like to the mobile station directly served by the relay station or the base station, and the receiving unit 602 is used for the mobile station directly served from the relay station or the base station. Receive various data, feedback, etc.

The scheduling unit 604 performs scheduling (scheduling 1'). The transmitting unit and the receiving unit are scheduled according to the determination result of the determining unit 603, so that when the determining unit 603 determines that the relay station has data to be transmitted to the base station, the mobile station is notified that the mobile station is not absolute. The downlink subframe is an MBSFN subframe, and the relay station is notified, The non-absolute downlink subframe is a specific subframe, and the non-absolute downlink subframe is used as an uplink relay link subframe, so that the receiving unit 602 is in the specific subframe that is the uplink relay link subframe. The data from the relay station is received in the uplink period.

In addition, the base station according to the second embodiment of the present invention may further include an adjustment unit that is based on the data to be transmitted by the base station to the relay station and the number, type, priority, urgency, etc. of the data to be transmitted to the base station by the relay station, or any of them. Combine, adjust the length of the downlink time slot and the uplink time slot in a specific subframe. The adjusting unit may also adjust the durations of the first protection time slot and the second protection time slot according to channel quality, QoS requirements, and the like.

Further, the second embodiment can be combined with the first embodiment, for example, in the frame structure 3 shown in Fig. 5, the subframe 7 and/or the subframe 9 can be set as a specific subframe.

It should be noted that although the above description of the embodiments of the present invention has been made by taking the frame structure 3 as an example, it should be noted that this is not a limitation of the present invention. For example, for frame structure 1, subframe #3 can be used as an uplink relay link subframe, and subframe #9 is also used as an MBFSN subframe. Subframe #8 can also be used as an uplink relay link subframe, and subframe #4 is also used as an MBFSN subframe. It is also possible to use both subframes #3 and #8 as uplink relay link subframes, and simultaneously use subframes #4 and #9 as MBFSN subframes.

For frame structure 4, one or more of subframes #4, #7, #8, and #9 may be set as specific subframes.

For frame structure 2, subframe #3 can be set to a specific subframe. Alternatively, subframe #2 may be used as an uplink relay link subframe, and subframe #8 may be used as an MBFSN subframe.

Embodiments of the present invention also disclose a relay apparatus including a transmitting unit, a receiving unit, a determining unit, and a scheduling unit. The determining unit determines whether there is data to be sent to the base station and whether the base station has data to send to the relay station, and the scheduling unit schedules the sending unit according to the judgment result of the determining unit, Thereby, the transmitting unit can receive data from the base station for the relay station in a downlink time slot of a specific time slot, and the receiving unit can transmit data of the relay station to the base station in an uplink time slot of the specific time slot.

The present invention discloses a frame structure, which includes a specific subframe, that is, includes as

The slot of the MBFSN subframe in turn includes a frame that is a slot of the uplink relay link subframe.

The present invention also discloses a frame structure in which an uplink subframe that is not used for transmitting ACK/NACK feedback for data transmitted on an absolute downlink access link is used as an uplink relay link subframe, and A downlink subframe transmitted on the uplink relay link subframe is received as a downlink relay link subframe.

The scheduling in Embodiments 1 and 2 will be described in more detail below.

Figure 12 shows the scheduling used to resolve the ACK/NACK collision problem for the TDD frame structure 3 shown in Figure 5 when there is no data communication relayed to the base station. In the example shown in FIG. 12, after the base station sends the relay data, the relay feeds back the ACK/NACK to the base station. As shown in FIG. 12, the subframe #7 and the subframe #8 in the frame #0 serve as the downlink. The relay link subframe is used to transmit the data of the BS to the RS. After the RS receives the data, according to the standard, the ACK/NACK needs to be fed back to the base station by the relay in the subframe #3 in the frame #1. In frame #3, the relay is in the transmitting state, so the scheduling mobile station does not perform data transmission to the relay station in the subframe corresponding to the uplink relay link subframe, and only schedules data transmission from the mobile station to the base station.

FIG. 13 shows the TDD frame structure 3 shown in FIG. 5. When there is a data communication relayed to the base station in a certain 10 ms frame, and there is no base station to relay data communication, the scheduling for solving the ACK/NACK collision problem is performed. In the example of FIG. 13, after the relay station transmits data to the base station, the base station does not feed back ACK/NACK to the relay. As shown in FIG. 13, the subframe #3 in the frame #1 is used as an uplink relay link subframe for transmitting data of the RS to the BS, that is, in the subframe #3, the relay is in the transmitting state, because the frame #0 The neutron frame #7 and the subframe #8 correspond to the subframe ACK/NACK in the subframe #3 in the frame #1, so the relay station to the mobile station is not scheduled in the subframe #7 and the subframe #8 in the frame #0. The data is transmitted, and only the data transmission from the base station to the mobile station is scheduled.

Fig. 14 shows the data communication for the relay station to the base station in a 10 ms frame for the TDD frame structure 3 shown in Fig. 5, and the scheduling for solving the ACK/NACK collision problem when there is no data communication from the base station to the relay station. After the relay station sends the data to the base station, the base station feeds back the ACK/NACK to the relay. As shown in FIG. 14, the subframe #3 in the frame #1 is used as the uplink relay link subframe, and is used for transmitting the data of the RS to the BS. That is, in subframe #3, the relay is in the transmitting state. As in the case of FIG. 12, since subframe #7 and subframe #8 in frame #0 correspond to subframe #3 in frame #1, ACK/NACK is fed back, so subframe #7 and subframe #8 in frame #0 are not. The data transmission of the relay to the mobile station is scheduled, and only the data transmission from the base station to the mobile station is scheduled. In addition, since the RS transmits data to the BS in the subframe #3 of the frame #1, according to the standard, the BS needs to feed back ACK/NACK in the subframe #8 of the frame #1, that is, the subframe of the RS in the frame #1. #8 is in the receiving state, so the data transmission from the RS to the UE is not scheduled, and only the data transmission from the BS to the UE is scheduled.

Fig. 15 shows the TDD frame structure 3 of the second embodiment. In a 10 ms frame, there is data communication relayed to the base station, and there is no scheduling of the ACK/NACK collision problem when there is no data communication from the base station to the relay station. After the relay station sends the data to the base station, the base station feeds back the ACK/NACK to the relay station. As shown in FIG. 15, the subframe #7 in the frame #0 is configured as a specific subframe designed to transmit the data of the RS to the BS, BS. After receiving the data, it is agreed that in the subframe #5 of the frame #1, the BS feeds back the ACK/NACK to the RS, that is, the RS is in the receiving state of the subframe #5, and the mobile station is notified that the subframe #5 is the MBSFN child. The frame does not schedule data transmission from the RS to the UE, and only schedules data transmission from the BS to the UE.

On the other hand, according to other embodiments of the present invention, when it is judged that only the base station transmits the data of the relay station or only the data transmitted by the relay station to the base station, a relatively simple frame structure can be employed between the relay station and the base station.

FIG. 16 shows an LTE TDD frame structure 3. In a 10 ms frame, there is a data communication between a base station and a relay station, and when there is no data communication between the relay station and the base station, the tone used to solve the ACK/NACK collision problem is adopted. Degree. After the base station sends the data to the relay station on the optional downlink relay link, the relay station feeds back to the base station.

ACK/NACK, as shown in FIG. 15, subframe #9 in frame #0 is used as a downlink relay link subframe for transmitting data of the BS to the RS. After the RS receives the data, it needs to be in the frame according to the standard. In subframe #4 in #1, the relay station feeds back ACK/NACK to the base station. That is, in the subframe #4, the relay station is in the transmitting state, so the data transmission from the mobile station to the relay station is not scheduled at this time, and only the data transmission from the mobile station to the base station is scheduled.

It should be noted here that since subframe #9 in frame #0 does not correspond to the ACK/NACK feedback of any uplink subframe, the subframe scheduling before subframe #9 is not constrained.

In this embodiment, the determining unit determines whether the relay station has a signal to be transmitted to the base station (such as ACK/NACK), and the scheduling unit performs scheduling (scheduling 4) so that when the relay station has a signal transmitted to the base station, the mobile station does not A signal is sent to the relay station. Specifically, the BS sends a data transmission to the RS in a certain downlink subframe, and notifies the mobile station that the downlink subframe is an MBSFN subframe, and performs scheduling, so that the mobile station does not transmit for the downlink subframe. The data is transmitted during the sub-frameback of the data.

FIG. 17 shows a data communication between a relay station and a base station in a 10 ms frame for an LTE TDD frame structure 3, and a scheduling used to solve an ACK/NACK collision problem when there is no data communication from a base station to a relay station, and the relay station is considered to be sent to the base station. After the data, the base station will feed back the ACK/NACK to the relay station. As shown in FIG. 17, the subframe #4 in the frame #1 is used as an uplink relay link subframe for transmitting data of the RS to the BS, that is, in the subframe #4, the relay station is in the transmitting state, due to the frame #1. Subframe #0 and subframe #0 in subframe #9 correspond to subframe ACK/NACK in subframe #1 in frame #1, so it is not scheduled in subframe #0 in subframe #1 and subframe #9 in frame #0 The data transmission from the mobile station to the relay station only schedules the data transmission from the base station to the mobile station.

In this embodiment of the present invention, a scheduling method in a base station includes a determining step of determining whether the relay station has data transmitted to the base station; a scheduling step (scheduling 5), determining that the relay station has to be transmitted to the base station In the case of data, an uplink subframe is selected as an uplink relay link subframe, so that the relay station can send data in the uplink subframe, and scheduling is performed so that the relay station is not in its uplink information. The downlink data transmitted to the mobile station in the subframe carried on the frame is scheduled, so that the mobile station does not send the uplink data to the relay station during the uplink subframe.

FIG. 18 shows an LTE TDD frame structure 3, in which a 10 ms frame has a data communication from a relay station to a base station, and when there is no data communication between the base station and the relay station, a scheduling method is adopted to solve the ACK/NACK collision problem, and the method considers the relay station to transmit After the base station data is sent, the base station feeds back the ACK/NACK to the relay station. As shown in FIG. 18, the subframe #4 in the frame #1 is used as an uplink relay link subframe for transmitting data of the RS to the BS, that is, in the subframe #4, the relay station is in the transmitting state, which is the same as in FIG. Since subframe #0 in frame #1 and subframe #9 in frame #0 correspond to subframe ACK/NACK in subframe #1 in frame #1, subframe #0 and frame #0 neutrons in frame #1 In frame #9, data transmission from the mobile station to the relay station is not scheduled, and only data transmission from the base station to the mobile station is scheduled. In addition, since the BS transmits data to the RS in the subframe #4 in the frame #1, according to the standard, the RS needs to feed back ACK/NACK in the subframe #0 of the frame #2, that is, the RS is in the frame #2. Frame #0 is in the transmitting state, so the data transmission from the RS to the UE is not scheduled, and only the data transmission from the BS to the UE is scheduled.

That is, in this embodiment of the present invention, a scheduling method in a base station includes a determining step of determining whether the relay station has data transmitted to the base station; a scheduling step (scheduling 6), determining that the relay station has to transmit When the data of the base station is selected, an uplink subframe is selected as the uplink relay link subframe, so that the relay station can send data in the uplink subframe, and scheduling is performed so that the relay station is not carrying its feedback information on the uplink subframe. The downlink data transmitted to the mobile station in the subframe, and the scheduling relay station causes the relay station to no longer carry a signal to the mobile station in the downlink subframe for the feedback carried in the uplink subframe. The base station also performs scheduling so that the mobile station does not transmit uplink data to the relay station during the uplink subframe.

Fig. 19 is a flow chart schematically showing a scheduling method of another embodiment of the present invention.

As shown in Fig. 19, first, the determination unit 603 of the base station determines whether the base station wants to transmit data to the relay station and determines whether the relay station is to transmit data to the base station (S700). If the base station wants to transmit data to the relay station and the relay station wants to transmit data to the base station (S701, YES), then at step S704', the scheduling unit of the base station 604 scheduling, so that the mobile station does not transmit uplink data in the uplink relay link subframe (subframe 3), and causes the relay station not to transmit data to the mobile station in the downlink relay link subframe (subframe 8) ( Scheduling Γ), and causing the transmitting unit 601 to transmit data to the relay station in the determined downlink relay link or the specific subframe in step S705, and causing the receiving unit 602 to receive the relay station in the specific subframe in step S706' The data. If the base station has data to transmit to the relay station but the relay station has no data to transmit to the base station (S702, YES), then at step S707', the scheduling unit 604 of the base station performs scheduling (scheduling 4), and in step S708, at MBSFN The data is transmitted to the relay station in the subframe. If the base station has no data to transmit to the relay station but the relay station has data to transmit to the base station (S703, YES), since the relay station is in the transmitting state in the subframe, the scheduling unit 604 of the base station performs scheduling (scheduling 5 or 6), The mobile station does not transmit uplink data in the uplink relay link subframe (S709), and then receives data from the relay station in the uplink relay link subframe (S710). o If the base station has no data to send to the relay station and the relay station has no data to When it is transmitted to the base station, the scheduling unit 604 of the base station performs the same conventional scheduling as the prior art without performing special scheduling (S711).

The above apparatus of the present invention may be implemented by hardware or by hardware in combination with software. The present invention relates to a computer readable program that, when executed by a logic component of a base station, enables the base station to implement the base station or component described above, or to cause the base station to implement the various methods described above Or a step. The present invention relates to a computer readable program that, when executed by a logic component of a relay station, enables the relay station to implement the relay station or component described above, or to cause the relay station to implement the various methods described above Or a step. The present invention also relates to a storage medium for storing the above program, such as a hard disk, a magnetic disk, an optical disk, a DVD, a flash, or the like.

The foregoing describes specific embodiments of the invention. Of course, it will be apparent to those skilled in the art that more permutations and combinations of the present invention are possible. All changes, modifications and variations within the spirit and scope of the invention are therefore intended to be included within the scope of the invention.

Claims

A base station comprising a transmitting unit (601), a receiving unit (602), a determining unit (603), and a scheduling unit (604), wherein

The determining unit (603) is configured to determine whether the relay station has a signal to be sent to the base station; the scheduling unit (604) schedules the receiving unit (602) according to the judgment result of the determining unit (603), so that the relay station has The signal to be transmitted to the base station, causing the receiving unit (602) to act as an uplink relay link subframe for transmitting feedback for receiving feedback for data transmitted on the absolute downlink access link subframe Receiving the signal from the relay station during one or more uplink subframes other than the subframe, and

The scheduling unit also schedules the mobile station and the relay station such that the mobile station does not transmit data to the relay station during the uplink relay link subframe.

2. The base station according to claim 1, wherein

The determining unit (603) is configured to determine whether the base station has a signal to be sent to the relay station; the scheduling unit (604) schedules the sending unit (601) according to the determination result of the determining unit (603), thereby When the base station has a signal to be sent to the relay station, the transmitting unit transmits the feedback as a downlink relay link subframe on a subframe corresponding to the uplink relay link subframe. Transmitting the signal to the relay station during one or more downlink subframes,

Notifying the mobile station by the scheduling unit: the downlink subframe that is the downlink relay link subframe is a broadcast multicast single frequency network subframe, and

The scheduling unit schedules the relay station such that the relay station does not transmit data to the mobile station during the downlink relay link subframe.

3. The base station according to claim 1, wherein the signal to be sent by the relay station to the base station comprises a data signal to be sent to the base station and a reception feedback signal to be sent to the base station. number.

The base station according to claim 2, wherein the signal to be transmitted by the base station to the relay station comprises a data signal to be transmitted to the relay station and a reception feedback signal to be transmitted to the relay station.

The base station according to claim 1, wherein the scheduling unit further performs scheduling, thereby

Receiving, by the relay station, a signal to be sent to the base station, receiving, by the receiving unit (602), in a downlink subframe other than the absolute downlink access link subframe as a specific subframe The signal of the relay station, and

The scheduling unit notifies the relay station that: the signal is transmitted in a downlink subframe corresponding to the specific subframe,

The scheduling unit notifies the mobile station that the downlink subframe corresponding to the specific subframe is a broadcast multicast single frequency network subframe.

The base station according to claim 5, wherein the specific subframe includes a period in which the base station transmits a signal to the mobile station.

The base station according to claim 6, wherein the specific subframe includes a transition period for converting the base station from a transmitting state to a receiving state and/or converting the base station from a receiving state to The transition period of the sending status.

The base station according to claim 6, wherein the base station further comprises an adjustment unit, and the adjustment unit is configured to adjust a duration of the base station in the receiving state in the specific subframe.

The base station according to claim 7, wherein the adjusting unit further adjusts a transition period for converting the base station from a transmitting state to a receiving state and/or converting the base station from a receiving state to a transmitting state. The length of the conversion period.

10. A base station, comprising: a transmitting unit (601), a receiving unit (602), a determining unit (603), and a scheduling unit (604), wherein

The determining unit (603) is configured to determine whether the relay station has a signal to be sent to the base station; the scheduling unit (604) schedules the receiving unit (602) according to the judgment result of the determining unit (603), thereby being a specific sub Receiving the signal from the relay station in a downlink subframe other than the absolute downlink access link subframe of the frame, and