CN104753649B - Method, communication equipment and mobile communication system for generating and sending feedback information - Google Patents

Abstract

Some embodiments of the present disclosure relate to methods, communication devices and mobile communication systems for generating and sending feedback information. Specifically, some embodiments use acknowledgment (ACK) as feedback information for special subframes in the feedback window to improve downlink traffic.

Description

Method, communication device and mobile communication system for generating and sending feedback information

technical field

Aspects of the present disclosure relate generally to wireless communication technologies, and in particular to methods, communication devices and mobile communication systems for generating and transmitting feedback information.

Background technique

Mobile communication systems, such as LTE‐TDD (Long Term Evolution‐Time Division Duplex, Long Term Evolution‐Time Division Duplex) systems use HARQ (Hybrid Automatic Repeat Request, Hybrid Automatic Repeat Request) to improve the reliability of data transmission. In the technical solution using HARQ, the communication equipment, such as user equipment (UE, User-Equipment), decodes the received downlink data packet, and if the decoding is successful, it will feedback to the base station (BS, Base Station) ACK (ACKnowledgment, positive response). If the decoding fails, NACK (Negative ACKnowledgment, negative response) is fed back to the base station. The base station will retransmit the data packet after receiving the NACK.

public content

Aspects of the present disclosure describe methods, communication devices and mobile communication systems for generating and sending feedback information.

According to an aspect of the present disclosure, a method for generating feedback information in a mobile communication system includes: receiving a downlink transmission; when the feedback information generated for a plurality of downlink subframes in the feedback window is an acknowledgment (ACK) When , an acknowledgment (ACK) is generated as the feedback information of the special subframe in the feedback window.

According to another aspect of the present disclosure, a method for sending feedback information in a mobile communication system includes: receiving a downlink transmission; when feedback information generated for a plurality of downlink subframes in a feedback window is an acknowledgment (ACK) , generating an acknowledgment (ACK) as feedback information of the special subframe in the feedback window; using physical uplink control channel format 1b channel selection (PUCCH format1b channel selection) to send the feedback information of the feedback window.

According to another aspect of the present disclosure, a communication device for a mobile communication system includes: a receiving module, configured to receive downlink transmission; a feedback information generation module, configured to generate feedback for multiple downlink subframes in a feedback window When the information is an acknowledgment (ACK), an acknowledgment (ACK) is generated as feedback information of the special subframe in the feedback window.

According to another aspect of the present disclosure, a mobile communication system includes a base station and user equipment. the base station is configured to send a downlink transmission; and the user equipment is configured to receive the downlink transmission and generate an acknowledgment (ACK) when the feedback information generated for the plurality of downlink subframes in the feedback window is an acknowledgment (ACK) The acknowledgment (ACK) is used as the feedback information of the special subframe in the feedback window.

Description of drawings

In the following description, aspects of the disclosure will be described with reference to the following drawings.

FIG. 1 is a schematic diagram of a mobile communication system including a base station and user equipment.

FIG. 2 is a schematic diagram of a frame structure of an LTE-TDD system.

Fig. 3 is a schematic diagram showing the association between uplink subframes and downlink/special subframes in the feedback window for LTE-TDD uplink/downlink configuration 2.

FIG. 4 is a flowchart of a method for generating feedback information in a mobile communication system according to an aspect of the present disclosure.

FIG. 5 is a schematic diagram of a communication device for a mobile communication system according to an aspect of the present disclosure.

Detailed ways

FIG. 1 shows a mobile communication system including a base station and user equipment. A physical channel between a user equipment and a base station can be divided into a downlink channel and an uplink channel. The downlink channel includes the physical downlink shared channel (PDSCH, Physical Downlink Shared Channel) for carrying the downlink shared channel (DL‐SCH, Downlink Shared Channel) and paging channel (PCH, Paging Channel), and the uplink The channel channel includes a physical uplink control channel (PUCCH, Physical Uplink Control Channel) for carrying feedback information in response to downlink transmission, a scheduling request (SR, Scheduling Request) and a channel quality indicator (CQI, Channel Quality Indicator).

FIG. 2 shows the frame structure of the LTE-TDD system. In this example, a radio frame (radio frame), that is, a system frame, has a length of, for example, 10 ms, and each radio frame is equally divided into two half frames with a length of 5 ms. Each half-frame contains 8 time slots with a length of 0.5ms and 3 special domains, namely downlink pilot time slot (DwPTS, Downlink Pilot frequencyTime Slot), guard interval (GP, Gap of Protection,) and uplink pilot time Slot (UpPTS, Uplink Pilotfrequency Time Slot). As shown in the figure, each radio frame is composed of 10 subframes (subframe), these 10 subframes include 2 special subframes and each special subframe is composed of the above-mentioned 3 special fields. In this example, the length of the 3 special fields is 1 ms. In one example, the time unit Ts=1/(15000×2048) seconds.

LTE-TDD separates the transmission and reception channels by time on the same carrier, so it can have different frame structures for uplink/downlink configurations. Table 1 shows seven different LTE-TDD uplink/downlink configurations, where D represents a downlink subframe, U represents an uplink subframe, and S represents the above-mentioned special subframe containing three special fields.

Table 1

As shown in Table 1, for LTE-TDD uplink/downlink configuration 2, subframes 2 and 7 are used for uplink transmission among the 10 subframes in one frame (system frame), and subframes 0, 3, 4, 5, 8, 9 are used for downlink transmission, and subframes 1 and 6 are used for transmission of special subframes.

In LTE releases, such as Rel-8/9, the downlink association index is disclosed in Table 2 below, where the association of uplink subframe n with downlink/special subframe n-k is shown. Specifically, after the decoding of the downlink/special subframe n-k is completed, the signaling of whether the data transmitted in the downlink/special subframe n-k needs to be retransmitted will be fed back to the base station on the uplink subframe n . Table 2 shows the value of k, which depends on the uplink and downlink configuration of the mobile communication system and the specific subframe number n.

Table 2

As shown in Table 2, for LTE-TDD uplink/downlink configuration 2, the values of k are 8, 7, 4, and 6, that is, the 8th, 7th, 4th, and 6th downlink/special subframes before the uplink subframe 2 Give feedback. For example, for an uplink subframe with sfn (system frame number, system frame number) = m, subframe (subframe) = 2, the feedback is associated with the following downlink/special subframes:

(sfn=m‐1, subframe=4),

(sfn=m‐1, subframe=5),

(sfn=m‐1, subframe=8),

(sfn=m‐1, subframe=6);

For uplink subframes with sfn (system frame number)=m, subframe=7, the feedback is associated with the following downlink/special subframes:

(sfn=m‐1, subframe=9),

(sfn=m, subframe=0),

(sfn=m, subframe=3),

(sfn=m, subframe=1).

Figure 3 shows the association of uplink subframes and downlink/special subframes in the feedback window for LTE-TDD uplink/downlink configuration 2.

In LTE releases, such as Rel-8/9, a multiplexing ACK/NACK feedback mode is defined. This mode uses different PUCCH (Physical Uplink Control Channel) channels and different modulation symbols on the channels to represent the feedback status composed of the feedback information of the downlink/special subframe. Specifically, for LTE-TDD uplink/downlink configuration 2, the multiplexed ACK/NACK feedback mode uses the index of the PUCCH channel and the 2-bit information b(0) and b(1) of PUCCH format 1b to indicate the feedback state, which is also called It is PUCCH format 1b channel selection (PUCCH format1b channel selection). Feedback information includes: ACK, NACK and DTX (Discontinuous Transmission, discontinuous transmission).

As mentioned above, for LTE-TDD uplink/downlink configuration 2, 4 downlink/special subframes need to be fed back within 1 uplink subframe, as shown in Figure 3 . Table 3 is the ACK/NACK multiplexing transmission mapping table in LTE Rel-8/9. In this table, feedback information (ie, HARQ-ACK, automatic repeat request response) HARQ-ACK(0), HARQ-ACK(1), HARQ-ACK(2), HARQ-ACK(3) correspond to the feedback 4 downlink/special subframes in the window. The feedback window refers to multiple downlink/special subframes associated with the same uplink subframe. In this table, Indicates the selected PUCCH channel resource, and 2-bit information b(0) and b(1) are used to form different modulation symbols. It can be understood that Table 3 can be used in any Rel-10 and above systems compatible with LTE Rel-8/9.

table 3

When the LTE-TDD uplink/downlink configuration is 2, when the downlink transmission uses the normal cyclic prefix mode, the special subframe configuration is 0 or 5, or when the downlink transmission uses the extended cyclic prefix mode, the special subframe configuration is 0 Or in the case of 4, when all downlink subframes of the feedback window transmitted in the physical downlink shared channel are successfully decoded, the following feedback information will be generated:

HARQ‐ACK(0)=ACK,

HARQ‐ACK(1)=ACK,

HARQ‐ACK(2)=ACK,

HARQ-ACK(3)=DTX.

Referring to FIG. 3 , for uplink subframe 2 with sfn=m, these feedback information correspond to subframes 4, 5, 8, and 6 in the feedback window with sfn=m−1, respectively. It can be seen that DTX (Discontinuous Transmission) will be fed back for the special subframe 6 at this time. This is because downlink pilot slots in special subframes with different characteristic subframe configurations and different cyclic prefix patterns have specific lengths, as shown in Table 4 below. When the special subframe is configured as 0 or 5 in normal cyclic prefix mode, or when the special subframe is configured as 0 or 4 in extended cyclic prefix mode, the downlink pilot slot cannot be used due to the specific length Physical downlink shared channel transmission.

For uplink subframe 7, the feedback situation is similar to uplink subframe 2, and uplink subframe 7 corresponding to subframe 9, 0, 3, and 1 in the feedback window will also feed back (ACK, ACK, ACK, DTX), where the subframe 1 is a special subframe.

Table 4

According to the above, according to Table 3 and Figure 3, the generated feedback information for downlink/special subframes (4, 5, 8, 6) and (9, 0, 3, 1) is HARQ-ACK(0)=ACK, HARQ-ACK(1)=ACK, HARQ-ACK(2)=ACK, HARQ-ACK(3)=DTX. These feedback information will correspond to n(P1U)CCH=n(P1U)CCH,1, coded b(0), b(1)=1,0. However, (ACK, ACK, ACK, DTX) will have the same channel selection and coding as (ACK, ACK, NACK/DTX, ACK) and (ACK, ACK, NACK/DTX, NACK/DTX) in Table 3. In this way, the base station will not be able to distinguish between (ACK, ACK, ACK, DTX) and (ACK, ACK, NACK/DTX, NACK/DTX), so as to judge that the downlink subframe 8 or 3 is wrongly received by the user equipment and scheduled for retransmission . This would cause unnecessary retransmissions and reduce downlink traffic.

FIG. 4 is a flowchart of a method of generating feedback information in an LTE-TDD system according to an aspect of the present disclosure.

As shown in Figure 4, in process 301, downlink transmission is received, and in process 302, the feedback information corresponding to the downlink subframe of the feedback window is generated, and in process 303, when all the downlink subframes of the feedback window are judged When all the feedback information is an acknowledgment (ACK), an acknowledgment (ACK) is generated as the feedback information of the special subframe in the feedback window. The resulting HARQ-ACK(0), HARQ-ACK(1), HARQ-ACK(2), HARQ-ACK(3) are (ACK, ACK, ACK, ACK), which correspond to the first Entries such that n(P1U)CCH=n(P1U)CCH,1 are selected, encoding b(0), b(1)=1,1, whereby retransmissions can be avoided. In this example, the special subframe is configured as 0 or 5 in the normal cyclic prefix mode, and is configured as 0 or 4 in the extended cyclic prefix mode.

According to another aspect of the present disclosure, a method for generating feedback information in a mobile communication system is disclosed. In this example, the method includes: receiving a downlink transmission; and when feedback information generated for a plurality of downlink subframes in a feedback window is an acknowledgment (ACK), generating an acknowledgment (ACK) as an acknowledgment (ACK) in the feedback window Feedback information of a special subframe.

In an example, the mobile communication system may be an LTE-TDD system, and the uplink/downlink configuration of the LTE-TDD system is 2.

In another example, if the downlink transmission uses a normal cyclic prefix mode, the special subframe configuration is 0 or 5, and wherein, if the downlink transmission uses an extended cyclic prefix mode, the special subframe configuration 0 or 4.

In another example, the feedback information is: acknowledgment, acknowledgment, acknowledgment, acknowledgment (ACK, ACK, ACK, ACK).

According to another aspect of the present disclosure, a method for sending feedback information in a mobile communication system is disclosed. In this example, the method includes: receiving a downlink transmission; when feedback information generated for a plurality of downlink subframes in a feedback window is an acknowledgment (ACK), generating an acknowledgment (ACK) as a special acknowledgment (ACK) in the feedback window Feedback information of the subframe; and sending the feedback information of the feedback window by using physical uplink control channel format 1b channel selection.

In an example, the mobile communication system may be an LTE-TDD system, and the uplink/downlink configuration of the LTE-TDD system is 2.

In another example, if the downlink transmission uses a normal cyclic prefix mode, the special subframe configuration is 0 or 5, and wherein, if the downlink transmission uses an extended cyclic prefix mode, the special subframe configuration 0 or 4.

In another example, the feedback information is: acknowledgment, acknowledgment, acknowledgment, acknowledgment (ACK, ACK, ACK, ACK).

In another example, the feedback information is sent according to a mapping table. The mapping table may be an ACK/NACK multiplexing transmission mapping table in LTE Rel-8/9.

It can be understood that when the physical uplink control channel contains other uplink control information (UCI, Uplink Control Information) other than ACK/NACK, such as scheduling request (SR, Scheduling Request) or channel quality indicator (CQI, Channel Quality Indicator), the base station will not confuse the feedback status because of the different encoding methods.

FIG. 5 is a schematic diagram of a communication device for a mobile communication system such as an LTE-TDD system according to an aspect of the present disclosure. As shown in the figure, the communication device includes: a receiving module for receiving downlink transmission; a feedback information generating module for when the feedback information generated for multiple downlink subframes in the feedback window is an acknowledgment (ACK) , generating an acknowledgment (ACK) as the feedback information of the special subframe in the feedback window.

In an example, the communication device may further include a sending module, configured to use a physical uplink control channel format 1b channel selection to send the feedback information of the feedback window.

In an example, the mobile communication system may be an LTE-TDD system, and the uplink/downlink configuration of the LTE-TDD system is 2.

In another example, if the downlink transmission uses a normal cyclic prefix mode, the special subframe configuration is 0 or 5, and wherein, if the downlink transmission uses an extended cyclic prefix mode, the special subframe configuration 0 or 4.

In another example, the feedback information is: acknowledgment, acknowledgment, acknowledgment, acknowledgment (ACK, ACK, ACK, ACK).

In another example, the feedback information is sent according to a mapping table. The mapping table may be an ACK/NACK multiplexing transmission mapping table in LTE Rel-8/9.

In another example, the communication device may be a user equipment or a relay station.

According to another aspect of the present disclosure, a mobile communication system is disclosed. The mobile communication system includes a base station and user equipment. The base station is configured to send a downlink transmission, and the user equipment is configured to receive the downlink transmission, and to generate an acknowledgment (ACK) when the feedback information generated for the plurality of downlink subframes in the feedback window is an acknowledgment (ACK). The acknowledgment (ACK) is used as the feedback information of the special subframe in the feedback window.

In an example, the user equipment is further configured to use physical uplink control channel format 1b channel selection to send the feedback information of the feedback window.

In an example, the mobile communication system may be an LTE-TDD system, and the uplink/downlink configuration of the LTE-TDD system is 2.

In another example, if the downlink transmission uses a normal cyclic prefix mode, the special subframe configuration is 0 or 5, and wherein, if the downlink transmission uses an extended cyclic prefix mode, the special subframe configuration 0 or 4.

In another example, the feedback information is: acknowledgment, acknowledgment, acknowledgment, acknowledgment (ACK, ACK, ACK, ACK).

In another example, the feedback information is sent according to a mapping table. The mapping table may be an ACK/NACK multiplexing transmission mapping table in LTE Rel-8/9.

In this way, unnecessary retransmissions are avoided, improving downlink traffic.

Although the disclosure has been shown and described with respect to one or more implementations, equivalent changes and modifications will become apparent to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. Furthermore, although a particular feature of the present disclosure may be disclosed with respect to only one of multiple implementations, for any given or particular application, such feature may be combined with one or more of the other implementations where it may be desirable and advantageous. combined with other features.

Claims (14)

1. A method for generating feedback information in a mobile communication system, comprising: receiving downlink transmissions; When the feedback information generated for multiple downlink subframes in the feedback window is an acknowledgment (ACK), generate an acknowledgment (ACK) as the feedback information of the special subframe in the feedback window, wherein the mobile communication system is Long Term Evolution-Time Division Duplex (LTE-TDD) system, and the uplink/downlink configuration of the LTE-TDD system is 2, wherein, if the downlink transmission uses the normal cyclic prefix mode, the special subframe configuration is 0 or 5, and wherein, if the downlink transmission uses the extended cyclic prefix mode, the special subframe configuration is 0 or 4. 2. The method according to claim 1, wherein the feedback information is: acknowledgment, acknowledgment, acknowledgment, acknowledgment (ACK, ACK, ACK, ACK). 3. A method for sending feedback information in a mobile communication system, comprising: receiving downlink transmissions; When the feedback information generated for multiple downlink subframes in the feedback window is an acknowledgment (ACK), generate an acknowledgment (ACK) as the feedback information of the special subframe in the feedback window; using physical uplink control channel format 1b channel selection (PUCCH format 1b channel selection) to send the feedback information of the feedback window, wherein the mobile communication system is a long-term evolution-time division duplex (LTE-TDD) system, and The uplink/downlink configuration of the LTE-TDD system is 2, wherein if the downlink transmission uses the normal cyclic prefix mode, the special subframe configuration is 0 or 5, and wherein, if the downlink transmission uses the extended In cyclic prefix mode, the special subframe configuration is 0 or 4. 4. The method according to claim 3, wherein the feedback information for each subframe in the feedback window is: acknowledgment, acknowledgment, acknowledgment, acknowledgment (ACK, ACK, ACK, ACK). 5. The method of claim 3, wherein the feedback information is sent according to a mapping table. 6. A communication device for a mobile communication system, comprising: a receiving module, configured to receive downlink transmissions; The feedback information generation module is used to generate an acknowledgment (ACK) as the feedback information of the special subframe in the feedback window when the feedback information generated for multiple downlink subframes in the feedback window is an acknowledgment (ACK), wherein , the mobile communication system is a Long Term Evolution-Time Division Duplex (LTE-TDD) system, and the uplink/downlink configuration of the LTE-TDD system is 2, wherein, if the downlink transmission uses a normal cyclic prefix mode, then The special subframe configuration is 0 or 5, and wherein, if the downlink transmission uses the extended cyclic prefix mode, the special subframe configuration is 0 or 4. 7. The communication device of claim 6, further comprising: A sending module, configured to use a physical uplink control channel format 1b channel selection (PUCCH format 1b channel selection) to send the feedback information of the feedback window. 8. The communication device according to claim 6, wherein the feedback information for each subframe in the feedback window is: acknowledgment, acknowledgment, acknowledgment, acknowledgment (ACK, ACK, ACK, ACK). 9. The communication device of claim 8, wherein the feedback information is sent according to a mapping table. 10. The communication device of claim 6, wherein the communication device is a user equipment or a relay station. 11. A mobile communication system, characterized in that, comprising: a base station configured to send a downlink transmission, The user equipment is configured to receive the downlink transmission, and when the feedback information generated for a plurality of downlink subframes in the feedback window is an acknowledgment (ACK), generate an acknowledgment (ACK) as a special acknowledgment (ACK) in the feedback window Subframe feedback information, wherein the mobile communication system is a Long Term Evolution-Time Division Duplex (LTE-TDD) system, and the uplink/downlink configuration of the LTE-TDD system is 2, wherein if the downlink transmission If the normal cyclic prefix mode is used, the special subframe configuration is 0 or 5, and wherein, if the downlink transmission uses the extended cyclic prefix mode, the special subframe configuration is 0 or 4. 12. The mobile communication system according to claim 11, wherein the user equipment is further configured to use physical uplink control channel format 1b channel selection (PUCCH format 1b channel selection) to transmit the feedback information of the feedback window. 13. The mobile communication system according to claim 11, wherein the feedback information for each subframe in the feedback window is: acknowledgment, acknowledgment, acknowledgment, acknowledgment (ACK, ACK, ACK, ACK) . 14. The mobile communication system of claim 13, wherein the feedback information is transmitted according to a mapping table.