CN101835194A - base station - Google Patents

Abstract

The invention relates to a base station and a method for communicating between the base station and a relay station. The base station includes a sending unit (601), a receiving unit (602), a judging unit (603) and a scheduling unit (604), wherein the judging unit (603) is used to judge 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 judging unit 603, so that when the relay station has a signal to be sent to the base station, the receiving unit (602) is used as an uplink relay link receiving data from said relay station during one or more uplink subframes of a subframe other than uplink subframes used to transmit reception feedback for data transmitted on an absolute downlink access link subframe, And the scheduling unit also schedules the mobile station, so that the mobile station does not send data to the relay station during the uplink relay link subframe.

Description

base station

technical field

The invention relates to a communication system, in particular to a communication system with a transparent relay station.

Background technique

With the rapid development of wireless multimedia services, users have higher and higher requirements on data communication capabilities and transmission quality. However, due to the influence of obstacles, shadows and other factors in the complex wireless environment, many communication dead spots are formed. These will make it difficult for users to obtain continuous high-speed and high-quality communication services. To solve this problem, wireless systems use relay stations to forward wireless communication signals between base stations and mobile stations to increase system throughput and user data rates.

In a wireless communication system including relay stations, mobile stations can be divided into two types according to their direct communication objects, namely mobile stations served by base stations and mobile stations served by relay stations. Figure 1 shows the data forwarding process of a typical relay station. As shown in Figure 1, UE 1 and UE 2 are mobile stations served by relay stations, and UE 3 is a mobile station served by base stations. UE 1 and UE 2 first send data to the relay station RS (relay station reception), and then RS sends the collected data (UE 1 data and UE 2 data) to the base station BS (relay station forwarding). It should be noted that FIG. 1 only shows that the relay station RS collects data from the mobile station served by the relay station and forwards the data to the base station. 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 adding a relay station in a wireless system does not have any impact on existing mobile station specifications, 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 called a relay link, and a link between a base station or a relay station and a mobile station is called an access link. The communication link from the base station to the relay station is called the downlink relay link, the communication link from the relay station to the base station is called the uplink relay link; the communication link from the base station or the relay station to the mobile station is called the downlink access link, and the mobile station The communication link from a station to a relay station or a base station is called an uplink access link.

During the process of making the present invention, the inventor found that in the TDD system, when a relay is introduced, there is a collision problem between ACK/NACK feedback and transmitted data. This is explained below.

In the TDD system, the added relay station has only one radio frequency link, so the relay station can only be in the receiving state or the transmitting state at a certain time, and cannot be in the transmitting and receiving state at the same time. In the TDD system, the relay station cannot be in the state of transmitting and receiving at the same time, so in the downlink relay link, the relay station is in the receiving state, so the relay station cannot send 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 frame structure of the existing LTE TDD standard is briefly described below. In LTE TDD, a frame is fixed at 10ms and includes 10 subframes of 1ms. According to the number of uplink subframes and downlink subframes, LTE TDD defines seven frame structures, namely frame structures 0-6. Some subframes in a 10ms frame are assigned to the downlink, called downlink subframes, and some subframes are assigned to the uplink, called uplink subframes. The base station sends data in the downlink subframe, and the mobile station or the relay station receives the data; the mobile station sends data in the uplink subframe, and the relay station or the base station receives the data. In the following, FIG. 2 is taken as an example for description. Figure 2 is the 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 in the figure. Subframe #1 is used for the base station to transmit synchronization signals, the mobile station to transmit access signals, and the mobile station and the base station to transmit and receive switching. U represents an uplink subframe, and subframes #2, #3, and #4 are shown in the figure. If the downlink subframe #9 is used for the data link from the base station to the relay station, then the subframe #9 is called a downlink relay link subframe, and other downlink subframes are called downlink access link subframes. If the uplink subframe #2 is used for the data link from the relay station to the base station, then the subframe #2 is called an uplink relay link subframe, and other uplink subframes are called uplink access link subframes.

For the downlink, the downlink relay link subframe can be configured as a broadcast multicast single frequency network (MBSFN) subframe, which is used to transmit data from the base station to the relay station. The time-frequency structure of a typical MBSFN subframe is shown in Figure 3, in which all mobile stations receive information such as control signaling and pilot symbols from the base station or relay station in the first one or two OFDM symbols of the MBSFN subframe, The subsequent OFDM symbols are invisible to all mobile stations, so the OFDM symbols following the MBSFN subframe can be used to transmit data signals from the base station to the relay station.

Since broadcast channels, addressing channels, synchronization channels, etc. need to be transmitted in downlink subframes or special subframes #0, #1, #5, #6, these four subframes cannot be used as MBSFN subframes, but can only be used as downlink The access link subframe, in this paper, for the convenience of description, the subframe that can only be used as the downlink access link subframe is called an absolute downlink access link subframe.

After the mobile station receives the data sent by the base station or the relay station, it needs to send a decoding response signal ACK/NACK (also referred to as receiving feedback in this article) to the base station and the relay station, where ACK indicates that the decoding is correct, and NACK indicates that the decoding is wrong. Signal. In order not to have any impact on the existing LTE TDD standard after joining the relay station, the ACK/NACK feedback must follow the existing LTE TDD standard. The existing standard stipulates that the time delay between receiving data and ACK/NACK feedback needs to be greater than 3ms. Taking FIG. 4 as an example, the third row corresponds to a fixed ACK/NACK feedback position corresponding to data transmitted in each subframe. As shown in Figure 4, ACK/NACK for data sent in downlink subframe #0 must be fed back in subframe #4, and ACK/NACK for data sent in uplink subframe #2 must be fed back in subframe #8. It should be noted that the subframe in which the ACK/NACK is fed back here is specified in the standard and generally does not change.

Since subframes #0, #1, #5, and #6 can no longer be used as MBSFN subframes, that is, downlink relay link subframes, these subframes can only be used for sending data from the base station to the mobile station or from the relay station to the mobile station. data. However, 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 sending state on 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.

Taking FIG. 4 as an example to illustrate the occurrence of such collisions, subframe #2 in FIG. 4 is an uplink relay link subframe, that is, data is transmitted from RS to 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 to the relay station the ACK/NACK corresponding to the data sent by the relay station in subframes #5 and #6, but since the subframe #2 has been used as an uplink relay link at this time, That is, the relay station is in the sending state, so the relay station will not be able to receive the ACK/NACK fed back by the mobile station served by the relay station. That is, a collision between ACK/NACK and sent data occurs.

The LTE TDD standard has not yet given a specific solution to the above-mentioned collision problem between ACK/NACK feedback and transmitted data.

Reception feedback (ACK/NACK) from a base station or a relay station to a mobile station may be transmitted in an MBSFN subframe. In some cases, there will also be a collision between the relay station sending 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 convenience of a clear and complete description of the technical solution of the present invention, and for the convenience of those skilled in the art to understand. It cannot be considered that the above technical solutions are known to those skilled in the art just because these solutions are described in the background of the present invention.

References for the present invention are listed below and are hereby incorporated by reference as if fully described in this specification.

1. [Patent Document 1]: Tak-ki Yu, et al., Method and apparatus for allocating peer-to-peer resource in relay based wireless communication system (US20090034447A1);

2. [Patent Document 2]: Jeffrey D.Bonta, et al., System and method of resource allocation within a communication system (US 20090034432A1);

3. [Patent Document 3]: Relay system and method for bandwidth allocation and scheduling (US 20080316954A1);

4. [Patent Document 4]: Radio resource management in wireless cellular networks having multihop relay stations (US 20080220790A1);

5. [Patent Document 5]: Flexible radio resource sharing in time and frequency domains among TDD communication systems (US 20080144612A1);

5. [Non-Patent Document 1]: Nokia, Considerations on TDD Relay, 3GPPTSG-RAN1, R1-090244;

6. [Non-Patent Document 2]: LG, UL subframe stealing for in-band relaying in TDD mode, 3GPP TSG-RAN1, R1-090225.

Contents of the invention

Embodiments of the present invention are made in view of the aforementioned problems in the prior art, and are used to solve or alleviate 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 sending unit, a receiving unit, a judging unit and a scheduling unit, wherein the judging unit is used to judge whether the relay station has a signal to be sent to the base station; The receiving unit performs scheduling, so that when the relay station has a signal to be sent to the base station, the receiving unit transmits on the subframe used for transmitting the absolute downlink access link as the uplink relay link subframe The signal from the relay station is received during one or more uplink subframes other than the uplink subframe of the data receiving feedback, and the scheduling unit also schedules the mobile station and the relay station, so that The mobile station does not send data to the relay station during the uplink relay link subframe.

Aspect 2. The base station according to aspect 1, wherein the judging unit is used to judge whether the base station has a signal to be sent to the relay station; the scheduling unit schedules the sending unit according to the judging result of the judging unit, Therefore, when the base station has a signal to be sent to the relay station, the sending unit receives feedback in the subframe corresponding to the uplink relay link subframe as the downlink relay link subframe Send the signal to the relay station during one or more downlink subframes transmitted on the Internet, and the scheduling unit notifies 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 does not send data to the mobile station during the downlink relay link subframe.

Aspect 3. The base station according to aspect 1, wherein the signal to be sent by the relay station to the base station includes a data signal to be sent to the base station and a reception feedback signal to be sent to the base station.

Aspect 4. The base station according to aspect 2, wherein the signal to be sent by the base station to the relay station includes a data signal to be sent to the relay station and a reception feedback signal to be sent 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, The signal from the relay station is received in a downlink subframe other than the absolute downlink access link subframe, and the scheduling unit notifies the relay station: in the downlink subframe corresponding to the specific subframe The signal is sent in a 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 during which the base station sends a signal to the mobile station.

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

Aspect 8. The base station according to aspect 6, wherein the base station further includes an adjustment unit configured to adjust the 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 the transition period for the base station to transition from the transmitting state to the receiving state and/or the transition period for the base station to transition from the receiving state to the transmitting state The length of the transition window.

Aspect 10, a base station, the base station includes a sending unit, a receiving unit, a judging unit, and a scheduling unit, wherein

The judging unit is used to judge 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 judging unit, so as to receive the signal from the relay station in a downlink subframe other than the absolute downlink subframe as a specific subframe, And the scheduling unit notifies the relay station: to send the signal in the downlink subframe corresponding to the specific subframe, and the scheduling unit notifies the mobile station: the downlink subframe corresponding to the specific subframe The downlink subframe is an MBSFN subframe.

Aspect 11. A scheduling method, comprising the following steps: judging step, judging whether the base station has data sent to the relay station, scheduling step, when judging that there is data sent to the relay station in the judging step, then in a certain downlink subframe, the base station sends data to the relay station, notifies the mobile station that the downlink subframe is an MBSFN subframe; and performs scheduling so that the mobile station does not transmit data to the relay station during the subframe during which the feedback of the data transmitted for the downlink subframe is transmitted .

Aspect 12. A scheduling method, comprising the following steps: a judging step, judging whether the relay station has data to be sent to the base station, and a scheduling step, selecting a certain uplink subframe as the uplink when judging that the relay station has data to be transmitted to the base station The subframe of the relay link is scheduled so that the relay station does not send the downlink data to the mobile station in the subframe whose feedback information is carried on the uplink subframe, and the scheduling is performed so that the mobile station does not send the downlink data to the mobile station during the uplink subframe. The relay station sends uplink data.

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

Aspect 14, a base station, the base station includes a sending unit, a receiving unit, a judging unit, and a scheduling unit, wherein the judging unit is used to judge whether the relay station has a signal to be sent to the base station and whether the base station has a signal to be sent to the base station The signal of the relay station; the scheduling unit schedules the receiving unit according to the judgment result of the judging unit, so that (1) when the relay station has a signal to be sent to the base station and the base station has a signal to be sent to the relay station, causing the receiving unit to operate on one or more uplink subframes other than uplink subframes used to transmit reception feedback for data transmitted on absolute downlink access link subframes as uplink relay link subframes receiving a signal from the relay station during the subframe, and the scheduling unit also schedules the mobile station and the relay station, so that the mobile station does not send data to the relay station during the uplink relay link subframe, causing the sending unit to send the data to the relay station during one or more downlink subframes whose reception feedback is transmitted on the uplink relay link subframe as a downlink relay link subframe , the scheduling unit notifies the mobile station that the downlink subframe corresponding to the downlink relay link subframe is an MBSFN subframe, and the scheduling unit schedules the relay station, so that the The relay station does not send data to the mobile station during the subframe of the downlink relay link; or when the relay station has a signal to be sent to the base station and the base station has a signal to be sent to the relay station, as a specific The data from the relay station is received in a downlink subframe other than the absolute downlink subframe of the subframe, and the scheduling unit notifies the relay station: in the subframe corresponding to the specific subframe (2) when the judgment step judges that the base station has a signal sent to the relay station but the relay station does not send a signal to the base station, so that in a certain downlink subframe, The base station sends a signal to the relay station to inform the mobile station that the downlink subframe is an MBSFN subframe; and schedules so that the mobile station does not transmit data to the relay station during the subframe during which the feedback of the data transmitted for the downlink subframe is transmitted; (3 ) When it is determined that the relay station has data to be transmitted to the base station, select a certain uplink subframe as the uplink relay link subframe, and perform scheduling so that the relay station is not in the subframe whose feedback information is carried on the uplink subframe Send downlink data to the mobile station, and perform scheduling so that the mobile station does not send uplink data to the relay station during the uplink subframe.

These and further aspects and features of the present invention will become more apparent with reference to the following description and drawings. In the description and drawings, specific embodiments of the invention are disclosed in detail, indicating the manner in which the principles of the invention may be employed. It should be understood that the invention is not thereby limited in scope. The invention embraces many changes, modifications and equivalents within the spirit and scope of the appended claims.

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

It should be emphasized that the term "comprising/comprising" when used herein refers to the presence of a feature, integer, step or component, but does not exclude the presence or addition of one or more other features, integers, steps or components.

Many aspects of the invention can be better understood with reference to the following figures. The components in the figures are not drawn to scale, merely illustrating the principles of the invention. For ease of illustration and description of some parts of the invention, corresponding parts in the drawings may be exaggerated, ie made larger relative to other parts in an exemplary device actually manufactured in accordance with the invention. Elements and features described in one drawing or one embodiment of the present invention may be combined with elements and features shown in one or more other drawings or embodiments. Furthermore, in the drawings, like numerals indicate corresponding parts in the several figures and may be used to indicate corresponding parts used in more than one embodiment.

Description of drawings

The accompanying drawings illustrate preferred embodiments of the present invention, and constitute a part of the specification, and are used to explain the principle of the present invention in further detail together with the text description. in:

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

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

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

Figure 4 shows the LTE TDD system frame structure 3, illustrating the collision problem of ACK/NACK;

FIG. 5 schematically shows a frame structure 3 according to the first embodiment of the present invention;

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

Fig. 7 schematically shows the processing in the base station BS shown in Fig. 6 when the frame structure 3 shown in Fig. 5 is adopted;

FIG. 8 schematically shows an operation sequence diagram of a communication system according to an embodiment of the present invention;

FIG. 9 schematically shows the structure of a specific subframe in an embodiment;

Fig. 10 schematically shows a frame structure 3 according to a second embodiment of the present invention;

Fig. 11 schematically shows another frame structure 3 according to the second embodiment of the present invention;

FIG. 12 shows the scheduling adopted for solving the ACK/NACK collision problem when there is no data communication relayed to the base station for the TDD frame structure 3 shown in FIG. 5;

FIG. 13 shows the scheduling for solving the ACK/NACK collision problem when there is data communication from the relay to the base station in a certain 10 ms frame for the TDD frame structure 3 shown in FIG. 5 , but there is no data communication from the base station to the relay;

FIG. 14 shows the scheduling for solving the ACK/NACK collision problem when there is data communication from the relay station to the base station in a certain 10 ms frame for the TDD frame structure 3 shown in FIG. 5 , but there is no data communication from the base station to the relay station;

FIG. 15 shows the TDD frame structure 3 of the second embodiment. When there is data communication from the relay to the base station in a certain 10 ms frame, and there is no data communication from the base station to the relay station, the scheduling is performed to solve the ACK/NACK collision problem;

Fig. 16 shows according to the embodiment of the present invention, for LTE TDD frame structure 3, when there is data communication from the base station to the relay station in a certain 10ms frame, when there is no data communication from the relay station to the base station, the ACK/NACK collision problem is adopted to solve the problem Scheduling;

Fig. 17 shows according to the embodiment of the present invention, for LTE TDD frame structure 3, when there is data communication from the relay station to the base station in a certain 10ms frame, when there is no data communication from the base station to the relay station, the scheduling adopted for solving the ACK/NACK collision problem ;

Figure 18 shows the LTE TDD frame structure 3, when there is data communication from the relay station to the base station in a certain 10ms frame, and there is no data communication from the base station to the relay station, the scheduling method adopted for solving the ACK/NACK collision problem; and

Fig. 19 schematically shows a flowchart of a scheduling method according to another embodiment of the present invention.

Detailed ways

In the following, a general communication system including a relay station is taken as an example, and the method and device in the embodiments of the present invention will be described with reference to the accompanying drawings.

first embodiment

In the first embodiment according to the invention, the base station will not transmit the uplink link for the feedback of the data transmitted on the absolute downlink access link subframe (eg subframe #0, #1, #5, #6) The subframe is set as an uplink relay link subframe. and set the ACK/NACK feedback for the data transmitted in the downlink access link subframe to be transmitted in the set uplink relay link subframe as the downlink subframe The subsequent link subframe is the MBSFN subframe.

Fig. 5 schematically shows the frame structure 3 according to the first embodiment of the present invention.

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

In frame structure 3, there are three non-absolute downlink subframes, ie, subframes #7, #8, and #9. The ACK/NACK feedback for data transmitted on subframe #9 is transmitted on subframe #4, while the ACK/NACK feedback for data transmitted on subframe #7 and #8 is transmitted on subframe #3 (also referred to as uplink The subframe corresponding to the relay link subframe, since it is transmitted on the corresponding subframe of the other frame). Therefore, both subframes #7 and #8 are set as downlink relay link subframes.

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

Fig. 6 shows 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 sending unit 601 , a receiving unit 602 , a judging unit 603 and a scheduling unit 604 .

The sending unit 601 is used to send various data, control instructions, pilot signals, etc. to the mobile station served by the relay station or base station, and the receiving unit 602 is used to receive various data, feedback, etc. from the mobile station directly served by the relay station or base station. The base station sends control signaling and pilots to the relay station and the mobile station in the first two or three OFDM symbols of each downlink subframe, where the control signaling contains the scheduling information of the base station, that is, notifies the mobile station or the relay station Which time-frequency unit of the frame receives data, and notifies the mobile station and the relay station which time-frequency unit of the uplink subframe to send data to the base station, etc. The control signaling also includes the ACK/NACK that the base station feeds back to the mobile station or the relay after receiving the data from the mobile station or the relay.

The judging unit 603 is configured to judge whether the base station has data to be sent to the relay station, and judge whether the relay station has data to be sent to the base station.

The scheduling unit 604 schedules the relay station and the mobile station according to the judgment result of the judging unit 603 .

In the first embodiment of the present invention, the transmitting unit does not transmit feedback for data transmitted on absolute downlink subframes (eg, subframes #0, #1, #5, #6) in the uplink Data, ACK/NACK, etc. from the relay station are received on the subframe (ie, the configured uplink relay link subframe). And the ACK/NACK feedback for the data transmitted on it in the downlink access link subframe is transmitted 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 processing in the base station BS shown in FIG. 6 in the case of employing the frame structure 3 shown in FIG. 5 .

First, the judging unit 603 of the base station judges whether the base station will send data to the relay station and judges whether the relay station will send a signal to the base station (S700). If the base station is to send a signal to the relay station and the relay station is 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 not in the uplink relay link subframe (subframe 3) Send uplink data, and make the relay station not send the signal to the mobile station in the downlink relay link subframe (subframe 8) (scheduling 1), and make the sending unit 601 on the determined downlink relay link in step S705 The signal is sent to the relay station, and in step S706, the receiving unit 602 is enabled to receive the signal from the relay station on the determined uplink relay link. If the base station has a signal to send to the relay station but the relay station has no signal to send to the base station (S702, yes), then since the relay station is in the receiving state in subframe #7 or #8, in order to avoid collision, in step S707, the base station's The scheduling unit 604 performs scheduling (scheduling 2), so that the relay station does not send data to the mobile station in the subframe (subframe #7 or #8), and notifies the mobile station that the subframe is an MBSFN subframe, and in step S708, Signals are sent to the relay station in the MBSFN subframe. If the base station has no signal to send to the relay station but the relay station has a signal to send to the base station (S703, yes), then because the relay station is in the sending state in this subframe, the scheduling unit 604 of the base station performs scheduling to make the mobile station 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 an uplink relay link subframe (S710). If the base station has no signal to send to the relay station and the relay station has no signal to send to the base station, the scheduling unit 604 of the base station does not perform special scheduling, but performs the same conventional scheduling as in the prior art (S711).

The judging unit 603 of the base station may determine whether to send data to the relay station according to the amount of data that can be transmitted in one downlink relay link subframe and the data stored at the base station that needs to be sent to the relay station. Specifically, for example, when the amount of stored data is greater than the amount of data that can be transmitted in one downlink relay link subframe, the base station may schedule data transmission to the relay station.

Similarly, the judging unit 603 of the base station judges whether the relay station has data to be sent to it according to the amount of data that can be transmitted in an uplink relay link subframe and the amount of data received by the relay station monitored by the base station. Specifically, for example, when the amount of data received by the relay station is greater than the amount of data that can be transmitted in one uplink relay link subframe, it may be determined that the relay station needs to send data to it.

Whether the mobile station sends data to the base station or the relay in a certain uplink subframe is determined by the control signaling sent by a corresponding downlink subframe before. If the base station allows the mobile station to send data in a certain uplink subframe, Then 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 this uplink subframe, and indicating the time-frequency resource occupied by the sending data wait.

Fig. 8 schematically shows an operation sequence diagram of the communication system according to the 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 first one or two OFDM symbols in the MBSFN subframe (subframe #7 or #8) which is the downlink relay link subframe and control signaling and other information (S100), the relay station sends information such as pilot frequency 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 following OFDM symbol (S120). And the relay station receives the information sent from the base station in the subsequent OFDM symbols.

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

At the same time, in the uplink relay link subframe #3, the base station receives information sent from the relay station; the relay station sends information to the base station (S130); for all mobile stations, under the scheduling of the base station, keep silence.

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

It can be seen from the above description that the frame structure followed by the mobile station has not changed at all, so 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 signaling from the base station and the relay station. For the relay station, it is used as a specific subframe for sending control signaling to the mobile station served by the relay station and for sending data to the base station. The base station is used as a specific subframe for sending control signaling to the mobile station served by the base station and for receiving data sent by the relay station.

Fig. 9 schematically shows the structure of a specific subframe in an embodiment. As shown in Figure 9, for all UEs, this subframe behaves as MBSFN, that is, in the previous one or two OFDM symbols, the BS and the RS respectively send control signaling and pilots for their respective served users. At this time, the BS for sending status. For the convenience of description, the time when the BS is in the sending state in the specific subframe is referred to as 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 sending state to the receiving state. This period of time may be called the first conversion period or the first protection period, or there may be no such period. Then the BS receives forwarded data from the RS in the next period, which is called the uplink period. Here, in this time slot, if the base station has ACK/NACK feedback to send to the relay station, the ACK/NACK feedback can be multiplexed with the data from the base station to the relay station for transmission. Finally, the BS changes from the receiving state to the sending state. This period of time may be called the second transition period or the second guard period, or may not have this period.

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

Fig. 10 schematically shows a frame structure 3 according to a second embodiment of the present invention. As shown in Figure 10, the non-absolute downlink subframe #7 in the downlink subframe is configured as a specific subframe, and will carry another non-absolute downlink subframe #7 of the reception feedback information for the data transmitted on the specific subframe A subframe, 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 informs 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 only exemplary, and other subframes, such as an absolute downlink subframe, may also be set as specific subframes. Likewise, an absolute downlink subframe may also be set as a feedback subframe carrying feedback for data transmitted on the specific subframe.

In addition, it should be noted that although subframe #9 is used as a downlink relay link subframe in the example of FIG. A subframe (when a specific subframe transmits both data from the BS to the RS and data from the RS to the BS). In addition, although subframe 7 is configured as a specific subframe in the example of FIG. 10 , other subframes (for example, subframe 8 and subframe 9 ) may be set as specific subframes. In addition, a plurality of specific subframes can be set.

When there is data communication from the relay station to the base station in a certain 10 ms frame, firstly in the specific subframe #7, the RS sends data to the BS. After receiving the data, the BS sends feedback on the received data in subframe #9 of the next frame. For the mobile station, both subframe #7 and subframe #9 are downlink subframes, so ACK/NACK collision will not occur. Similarly, in a certain 10ms frame, when the base station has data communication with the relay station, it transmits in subframe #9, and the feedback of the RS on the received data can be sent in subframe #7 of the next frame. For the mobile station, both subframe #7 and subframe #9 are downlink subframes, so ACK/NACK collision will not occur.

In addition, in the case where no other MBSFN is set except for the specific subframe, the feedback of the specific subframe may be set as the specific subframe itself. This is shown, for example, in FIG. 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 has not changed, although the frame structure between the relay station and the base station is the same as the frame structure between the base station and the mobile station and the frame structure between the relay station and the mobile station. The structures are different, but the agreement between the base station and the relay station is relatively easy to implement.

In the second embodiment, the sending unit 601 of the base station is used to send various data, control instructions, pilot signals, etc. Receive various data, feedback, etc.

The judging unit 603 is configured to judge whether the base station has data to be sent to the relay station, and judge whether the relay station has data to be sent to the base station.

The scheduling unit 604 performs scheduling (scheduling 1') to schedule the sending unit and the receiving unit according to the judgment result of the judging unit 603, so that when the judging unit 603 judges that the relay station has data to be sent to the base station, it notifies the mobile station of a non-absolute The downlink subframe is an MBSFN subframe, and the relay station is notified that 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 acts as The data from the relay station is received in the uplink period in the specific subframe of the uplink relay link subframe.

In addition, the base station according to the second embodiment of the present invention may further include an adjustment unit, which adjusts the data according to the data to be sent by the base station to the relay station and the quantity, type, priority, urgency, etc., or any of them. combination to adjust the lengths of downlink time slots and uplink time slots in a specific subframe. The adjustment unit may also adjust the duration of the first guard time slot and the second guard time slot according to channel quality, QoS requirements and the like.

In addition, the second embodiment may be combined with the first embodiment. For example, in frame structure 3 shown in FIG. 5 , subframe 7 and/or subframe 9 may be set as specific subframes.

It should be noted that although the above description of the embodiments of the present invention is based on 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 may be used as an uplink relay link subframe, and subframe #9 may be used as an MBFSN subframe at the same time. It is also possible to use subframe #8 as an uplink relay link subframe, and simultaneously use subframe #4 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 may be set as 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 at the same time.

The embodiment of the present invention also discloses a relay device, which includes a sending unit, a receiving unit, a judging unit and a scheduling unit. The judging unit judges whether there is data to be sent to the base station and whether the base station has data to be sent to the relay station, and the scheduling unit schedules the sending unit according to the judging result of the judging unit, so that the sending unit can receive data from the base station in a downlink time slot of a specific time slot. The data for the relay station, and the receiving unit can send the data from the relay station to the base station in the uplink time slot of the specific time slot.

The invention discloses a frame structure, which includes a specific subframe, that is, a frame including time slots as MBFSN subframes and time slots as uplink relay link subframes.

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

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

FIG. 12 shows the scheduling adopted to solve the ACK/NACK collision problem when there is no data communication relayed to the base station for the TDD frame structure 3 shown in FIG. 5 . In the example shown in Figure 12, it is considered that after the base station sends data to the relay, the relay will feed back ACK/NACK to the base station, as shown in Figure 12, subframe #7 and subframe #8 in frame #0 are used as downlink The relay link subframe is used to transmit data from the BS to the RS. After the RS receives the data, according to the standard, the relay needs to feed back ACK/NACK to the base station in the subframe #3 of the frame #1, that is, the subframe In frame #3, the relay is in the transmitting state, so the scheduling mobile station does not transmit data 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 data communication from the relay to the base station in a certain 10 ms frame, but there is no data communication from the base station to the relay, the scheduling is performed to solve the ACK/NACK collision problem. In the example in FIG. 13 , after the relay station sends data to the base station, the base station does not feed back ACK/NACK to the relay. As shown in Figure 13, subframe #3 in frame #1 is used as an uplink relay link subframe for transmitting data from the RS to the BS, that is, in subframe #3, the relay is in the sending state, and because frame #0 Subframe #7 and subframe #8 correspond to subframe #3 feeding back ACK/NACK in frame #1, so subframe #7 and subframe #8 in frame #0 do not schedule data transmission from the relay station to the mobile station, only schedule Data transmission from base station to mobile station.

FIG. 14 shows the scheduling for solving the ACK/NACK collision problem when there is data communication from the relay station to the base station in a certain 10 ms frame and there is no data communication from the base station to the relay station for the TDD frame structure 3 shown in FIG. 5 . After the relay station sends data to the base station, the base station will feed back ACK/NACK to the relay, as shown in Figure 14, subframe #3 in frame #1 is used as an uplink relay link subframe for transmitting data from RS to BS, That is, in subframe #3, the relay is in the transmitting state. Same as in FIG. 12, since subframe #7 and subframe #8 in frame #0 correspond to subframe #3 in frame #1 feeding back ACK/NACK, so in frame #0, subframe #7 and subframe #8 do not The data transmission from 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, after the RS sends 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 RS in the subframe of the frame #1 #8 is in the receiving state, so the data transmission from the RS to the UE is not scheduled, but only the data transmission from the BS to the UE is scheduled.

Figure 15 shows the TDD frame structure 3 of the second embodiment. When there is data communication from the relay to the base station in a certain 10 ms frame, but there is no data communication from the base station to the relay station, the scheduling is performed to solve the ACK/NACK collision problem. After the relay station sends data to the base station, the base station will feed back ACK/NACK to the relay station. As shown in Figure 15, subframe #7 in frame #0 is configured as a specific subframe designed for sending data from RS to BS, and BS After receiving the data, it is agreed that the BS will feed back ACK/NACK to the RS in the subframe #5 of the frame #1, that is, the RS is in the receiving state in the subframe #5, and at this time, the mobile station is notified that the subframe #5 is an MBSFN subframe. frame, does not schedule the data transmission from the RS to the UE, but only schedules the 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 sent by the relay station to the base station, a relatively simple frame structure may also be adopted between the relay station and the base station.

Figure 16 shows the LTE TDD frame structure 3, when there is data communication from the base station to the relay station in a certain 10ms frame, and there is no data communication from the relay station to the base station, the scheduling adopted to solve the ACK/NACK collision problem. After the base station sends data to the relay station on the optional downlink relay link, the relay station will feed back ACK/NACK to the base station, as shown in Figure 15, subframe #9 in frame #0 is used as the subframe of the downlink relay link, using When transmitting data from the BS to the RS, the RS needs to feed back ACK/NACK to the base station by the relay station in the subframe #4 of the frame #1 after receiving the data according to the standard. That is, in subframe #4, the relay station is in the transmitting state, so at this time, data transmission from the mobile station to the relay station is not scheduled, and only 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 ACK/NACK feedback of any uplink subframe, the scheduling of subframes before subframe #9 is not constrained.

In this embodiment, the judgment unit judges whether the relay station has a signal (such as ACK/NACK) to be sent to the base station, and the scheduling unit performs scheduling (scheduling 4), so that when the relay station has a signal to be sent to the base station, the mobile station does not It will send a signal to the relay station. Specifically, the BS sends data to the RS in a certain downlink subframe, notifies the mobile station that the downlink subframe is an MBSFN subframe, and schedules it so that the mobile station does not transmit data for the downlink subframe. The data is transmitted during the feedback subframe of the data.

Figure 17 shows for LTE TDD frame structure 3, when there is data communication from the relay station to the base station in a certain 10ms frame, and there is no data communication from the base station to the relay station, the scheduling adopted to solve the problem of ACK/NACK collision, considering the relay station to the base station After receiving the data, the base station will feed back ACK/NACK to the relay station. As shown in Figure 17, subframe #4 in frame #1 is used as an uplink relay link subframe for transmitting data from the RS to the BS, that is, in subframe #4, the relay station is in the transmitting state. Subframe #0 and subframe #9 in frame #0 correspond to ACK/NACK feedback in subframe #4 in frame #1, so there is no scheduling in subframe #0 in frame #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 judging step, judging whether the relay station has data to be sent to the base station; a scheduling step (scheduling 5), when judging that the relay station has data to be transmitted to the base station , choose a certain uplink subframe as the uplink relay link subframe, so that the relay station can send data in the uplink subframe, and perform scheduling so that the relay station is not in the subframe whose feedback information is carried on the uplink subframe Send downlink data to the mobile station, and perform scheduling so that the mobile station does not send uplink data to the relay station during the uplink subframe.

Figure 18 shows the LTE TDD frame structure 3. When there is data communication from the relay station to the base station in a certain 10ms frame, but there is no data communication from the base station to the relay station, the scheduling method adopted to solve the ACK/NACK collision problem takes into account the relay station sending After sending data to the base station, the base station will feed back ACK/NACK to the relay station. As shown in Figure 18, subframe #4 in frame #1 is used as an uplink relay link subframe for transmitting data from the RS to the BS, that is, in subframe #4, the relay station is in the transmitting state, which is the same as in Figure 9 , since subframe #0 in frame #1 and subframe #9 in frame #0 correspond to subframe #4 in frame #1 feeding back ACK/NACK, so subframe #0 in frame #1 and subframe #0 in frame #0 In frame #9, data transmission from the mobile station to the relay station is not scheduled, but only data transmission from the base station to the mobile station is scheduled. In addition, after the BS sends data to the RS in the subframe #4 of 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 in the subframe #2 of the frame #2 Frame #0 is in the sending state, so the data transmission from the RS to the UE is not scheduled, but 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 judging step, judging whether the relay station has data to send to the base station; For data, a certain 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 does not use the subframe whose feedback information is carried on the uplink subframe. The downlink data sent to the mobile station in the frame, and the relay station is scheduled so that the relay station no longer carries the feedback carried in the uplink subframe to send signals to the mobile station in the downlink subframe. The base station also performs scheduling so that the mobile station does not send uplink data to the relay station during the uplink subframe period.

Fig. 19 schematically shows a flowchart of a scheduling method according to another embodiment of the present invention.

As shown in FIG. 19, first, the judgment unit 603 of the base station judges whether the base station will send data to the relay station and judges whether the relay station will send data to the base station (S700). If the base station is to send data to the relay station and the relay station is to send data 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) Do not send uplink data, and make the relay station not send data to the mobile station in the subframe (subframe 8) of the downlink relay link (scheduling 1'), and in step S705, make the sending unit 601 transmit in the determined downlink relay link In step S706', the receiving unit 602 is enabled to receive data from the relay station in the specific subframe. If the base station has data to send to the relay station but the relay station has no data to send to the base station (S702, yes), then in step S707′, the scheduling unit 604 of the base station performs scheduling (scheduling 4), and in step S708, in the MBSFN subframe Send data to the relay station. If the base station has no data to send to the relay station but the relay station has data to send to the base station (S703, Yes), then because the relay station is in the sending state in this subframe, the scheduling unit 604 of the base station performs scheduling (scheduling 5 or 6), so that 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). If the base station has no data to send to the relay station and the relay station has no data to send to the base station, the scheduling unit 604 of the base station does not perform special scheduling, but performs the same conventional scheduling as in the prior art (S711).

The above devices of the present invention can be implemented by hardware, or by combining hardware and software. The present invention relates to such a computer-readable program, when the program is executed by the logic components of the base station, it can make the base station realize the above-mentioned base station or constituent parts, or make the base station realize the above-mentioned various methods or steps. The present invention relates to such a computer-readable program, when the program is executed by the logic unit of the relay station, it can make the relay station realize the above-mentioned relay station or constituent parts, or make the relay station realize the above-mentioned various methods or steps. The present invention also relates to a storage medium for storing the above program, such as hard disk, magnetic disk, optical disk, DVD, flash, etc.

Specific embodiments of the present invention have been described above. Of course, those of ordinary skill in the art will appreciate that many more permutations and combinations of the present invention are possible. Therefore, all changes, modifications and changes within the spirit and scope of the claims of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A base station, the base station comprising a sending unit (601), a receiving unit (602), a judging unit (603) and a scheduling unit (604), wherein The judging unit (603) is used to judge 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 judging unit (603), so that when the relay station has a signal to be sent to the base station, the receiving unit (602) is used as an uplink receiving from the relay station during one or more uplink subframes other than uplink subframes of the link subframe used to transmit reception feedback for data transmitted on the absolute downlink access link subframe of the signal, and The scheduling unit also schedules the mobile station and the relay station, so that the mobile station does not send data to the relay station during the uplink relay link subframe. 2. The base station according to claim 1, characterized in that, The judging unit (603) is used to judge 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 judgment result of the judging unit (603), so that when the base station has a signal to be sent to the relay station, the sending unit acts as a downlink relay link sending said signal to said relay station during one or more downlink subframes of a subframe whose reception feedback is transmitted on a subframe corresponding to the uplink relay link subframe, The scheduling unit notifies the mobile station that the downlink subframe serving as the downlink relay link subframe is a broadcast multicast single frequency network subframe, and The scheduling unit schedules the relay station so that the relay station does not send 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 includes a data signal to be sent to the base station and a reception feedback signal to be sent to the base station. 4. The base station according to claim 2, wherein the signal to be sent by the base station to the relay station includes a data signal to be sent to the relay station and a reception feedback signal to be sent to the relay station. 5. The base station according to claim 1, wherein the scheduling unit also performs scheduling, so that When the relay station has a signal to be sent to the base station, make the receiving unit (602) receive the signal from said signal of the relay station, and The scheduling unit notifies the relay station: to send the signal in the 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. 6. The base station according to claim 5, wherein the specific subframe includes a period during which the base station sends signals to the mobile station. 7. The base station according to claim 6, characterized in that, the specific subframe includes a switching period for switching the base station from a transmitting state to a receiving state and/or switching the base station from a receiving state to a receiving state The transition period for sending states. 8. The base station according to claim 6, wherein the base station further comprises an adjusting unit, the adjusting unit is configured to adjust the duration of the receiving state of the base station in the specific subframe. 9. The base station according to claim 7, wherein the adjusting unit further adjusts the transition period for the base station to transition from the transmitting state to the receiving state and/or the transition period for the base station to transition from the receiving state to the transmitting state. The length of the transition window. 10. A base station, comprising a sending unit (601), a receiving unit (602), a judging unit (603) and a scheduling unit (604), wherein The judging unit (603) is used to judge 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 judging unit (603), so that in the downlink subframes other than the absolute downlink access link subframes that are specific subframes receiving said signal from the relay station, and The scheduling unit notifies the relay station: to send the signal in the 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.

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