Background technology
Relaying (Relay) technology is as the key technology of B3G/4G, and oneself occupies critical role in the research of Long Term Evolution (LTE, Long Term Evolution) standard.In system, introduce RN and can play the effect of improving the network coverage, improving user throughput, but RN has changed original network configuration simultaneously.Fig. 1 is the composition structural representation of junction network, as shown in Figure 1, the TDD system of introducing RN has been divided into two-hop link by the one hop link between original eNB in LTE network (enhanced Node B) and UE, back haul link (Backhaul Link) between formation eNB and RN and the Access Link between RN and UE, the UE that accepts service under RN covers is called relay domain UE.
In LTE system, signal is unit with transmission block (TB, Transmission Block), mixes the feedback of automatic repeat request (HARQ, Hybrid Automatic Repeat Request) process and retransmits accordingly.Receiving terminal receives after signal, according to the receipt decoding situation of signal, generates confirmations/non-confirmation (ACK/NACK) information, if receive correctly, generates ACK information, if receive incorrect, generation nack message, and ACK/NACK information is fed back to transmitting terminal; Transmitting terminal is for further processing according to the feedback information receiving, if receive ACK information, continues the new data of transmission, if receive nack message, the corresponding data that take defeat is transferred to receiving terminal again.
According to the re-transmission mode of data, HARQ process can be divided into two kinds of synchronous HARQ and asynchronous HARQ.Wherein, synchronous HARQ process refers to after transmitting terminal receives NACK feedback, carries out the re-transmission of data in the set time position of making an appointment.Such as, the HARQ process of LTE TDD system uplink transfer of data adopts synchronous HARQ, UE receives after the NACK feedback and corresponding ascending resource mandate (UL Grant) information of eNB, the uplink retransmission of the enterprising row data of sub-frame of uplink of time-scale (Timing Table) defined arranging in system.
Table 1 is the Timing Table of the existing protocol specification of LTE TDD system, and wherein " D " represents descending sub frame, and " U " represents sub-frame of uplink, and " S " represents special subframe; According to agreement, stipulate, 1 radio frames (frame) is 10ms, and subframe (subframe) formation by 10 1ms, is expressed as #0~#9, TDD system has 7 kinds to the configuration mode of uplink and downlink subframe in radio frames, is Configuration0~Configuration6.As shown in table 1, stipulated the descending sub frame of carrying nack message and UL Grant information, and fixing sequential relationship between the uplink retransmission resource of distributing, be that eNB issues nack message and UL Grant information in n subframe to UE, UE uses distributed resource to carry out uplink retransmission according to these information in n+k subframe.The regulation of sub-frame interval k is as shown in table 1, such as k value corresponding to the #1 subframe of Configuration0 is 6, be illustrated in UE in #1 subframe and receive after NACK feedback and UL Grant information, in #7 subframe, use distributed re-transmission resource to carry out uplink retransmission to corresponding data.
Because Timing Table has fixed the descending sub frame of carrying UL Grant and the sub-frame interval of its uplink retransmission resource place sub-frame of uplink distributing, the sequential relationship of formation system regulation.ENB, when configuration indication UE carries out uplink retransmission, only need indicate the configuration of concrete physical resource with UL Grant information, does not need the subframe that retransmits resource place that indication distributes.
Table 1
In introducing the TDD system of RN, network configuration has become the double bounce structure of eNB-RN-UE from the single-hop networks of original eNB-UE.While carrying out the relay forwarding of data due to RN between eNB and UE, RN can not receive simultaneously and transmit in same frequency range, therefore, RN can not carry out to eNB the transmission of upstream data when receiving from relay domain UE upward signal, similarly, RN, when carrying out transmitting uplink data to eNB, also cannot receive the upward signal of relay domain UE.Also be there is to kindred circumstances in the transmission of downstream signal, when RN receives the downstream signal of eNB, cannot, simultaneously to relay domain UE transmitting downstream signal, when RN launches downstream signal to relay domain UE, also cannot receive the downstream signal from eNB.For RN, Backhaul Link and Access Link need to divide with time division way.
Consider that RN is in the time-division property of Backhaul Link and Access Link, if adopt the Timing Table mode with fixed timing relationship to be configured the uplink retransmission of relay domain UE, under TDD system, can bring such problem: when system configuration RN carries out uplink to eNB in n subframe, n subframe may be also the subframe that certain relay domain UE need carry out uplink retransmission simultaneously, and RN cannot receive the uplink retransmission signal of this relay domain UE in this subframe, this will cause this ascending HARQ to retransmit unsuccessfully, thereby caused RN invalid to the scheduling of this uplink retransmission, resource utilization and the user throughput of system have been reduced.
Summary of the invention
In view of this, main purpose of the present invention is to provide a kind of method of uplink retransmission of access link, can improve the flexibility of uplink retransmission of access link configuration, improves HARQ retransmission efficiency, resource utilization ratio and user throughput.
Another object of the present invention is to provide a kind of system of uplink retransmission of access link, can improve the flexibility of uplink retransmission of access link configuration, improve HARQ retransmission efficiency, resource utilization ratio and user throughput.
For achieving the above object, technical scheme of the present invention is achieved in that
A method that realizes uplink retransmission of access link, the method comprises the following steps:
Relay station RN generates non-confirmation NACK feedback to the uplink of relay domain UE, and the corresponding uplink retransmission subframe that arranges of the system of judging and self are during to the back haul link uplink transmission conflict of base station, RN is that described relay domain UE collocating uplink retransmits additional indication information, and sends to NACK feedback and ascending resource authorization message the described relay domain UE that needs uplink retransmission;
Described relay domain UE obtains the additional indication information of uplink retransmission, obtain the configuration indication to uplink retransmission subframe, and the re-transmission resource of distributing according to ascending resource authorization message in the uplink retransmission subframe of indication is carried out uplink retransmission.
The additional indication information of described uplink retransmission is skew indication information s; Wherein s round numbers, and after skew adjustment, indicated re-transmission subframe is sub-frame of uplink.
Described relay domain UE obtains the configuration of uplink retransmission subframe is indicated and carried out uplink retransmission, specifically comprises:
On the basis of the n+k subframe of stipulating at the time-scale of system setting, carry out the skew of s subframe and adjust, in n+k+s subframe, the re-transmission resource that relay domain UE distributes according to ascending resource authorization message is carried out uplink retransmission;
Wherein, n subframe represents the descending sub frame at ascending resource authorization message place, and k is the sub-frame interval of the ascending resource place subframe of the ascending resource authorization message place subframe that provides of time-scale and its configuration indication.
The additional indication information of described uplink retransmission is specific sub-frame indication information c;
Described specific sub-frame indication information c is certain sub-frame of uplink of current wireless frame, or certain sub-frame of uplink of certain radio frames after current wireless frame.
Described relay domain UE obtains the configuration of uplink retransmission subframe is indicated and carried out uplink retransmission, specifically comprises:
Described relay domain UE is directly in the indicated c subframe of specific sub-frame indication information c, and the re-transmission resource of distributing according to ascending resource authorization message is carried out uplink retransmission.
The additional indication information of described uplink retransmission is sub-frame of uplink skew indication information t, wherein t round numbers.
Described relay domain UE obtains uplink retransmission subframe and carries out uplink retransmission, specifically comprises:
On the basis of the n+k subframe of stipulating at the time-scale setting in advance, carry out sub-frame of uplink skew and adjust, on t sub-frame of uplink after n+k subframe, the re-transmission resource that relay domain UE distributes according to ascending resource authorization message is carried out uplink retransmission;
Wherein, n subframe represents the descending sub frame at ascending resource authorization message place, and k is the sub-frame interval of the ascending resource place subframe of the ascending resource authorization message place subframe that provides of time-scale and its configuration indication.
The method also comprises: when described RN judges uplink retransmission subframe that system sets in advance and do not conflict to the back haul link uplink of base station with self, RN sends to relay domain UE by NACK feedback and UL authorization message, in the uplink retransmission subframe of the time-scale regulation that relay domain UE arranges in system, the re-transmission resource of distributing according to UL authorization message is carried out uplink retransmission.
Described RN further sends to relay domain UE by the additional indication information of the uplink retransmission of configuration;
The additional indication information of described uplink retransmission is set to without indicated value.
Realize a system for uplink retransmission of access link, this system comprises relay station RN and relay domain UE, wherein,
RN, for carrying out back haul link uplink according to base station to the configuration information of RN uplink; When the sub-frame of uplink of stipulating at the time-scale of system setting can not carry out uplink retransmission to RN for relay domain UE, by uplink retransmission, add the uplink retransmission subframe position that indication information is adjusted relay domain UE, indication relay domain UE carries out uplink retransmission on other available sub-frame of uplink;
Relay domain UE, for the additional indication information of NACK feedback, ascending resource authorization message and uplink retransmission according to RN, or NACK feedback and ascending resource authorization message, obtain the indication to uplink retransmission subframe position, and the re-transmission resource of distributing according to ascending resource authorization message is carried out uplink retransmission in the uplink retransmission subframe obtaining.
Described RN at least comprises judging unit and processing unit, wherein,
Judging unit, for generating at RN after non-confirmation feedback, configuration information according to system to back haul link uplink, whether the corresponding uplink retransmission subframe that judges system setting exists and conflicts to the back haul link uplink of base station with self, and by judged result notifier processes unit;
Processing unit, for the uplink retransmission of the judged result configuration indication relay domain UE according to judging unit; If receive, judgment result is that and have conflict, collocating uplink retransmits additional indication information, and sends to described relay domain UE with NACK feedback and ascending resource authorization message;
If receive, judgment result is that not conflict, to described relay domain UE, send NACK feedback and ascending resource authorization message; Or the additional indication information of uplink retransmission by being configured to without indicated value, sends to described relay domain UE with NACK feedback and ascending resource authorization message.
The technical scheme providing from the invention described above can be found out, when the sub-frame of uplink of the Timing of system setting Table regulation can not carry out uplink retransmission to RN for relay domain UE, RN adds indication information by uplink retransmission, adjust the position of uplink retransmission subframe, indication relay domain UE carries out uplink retransmission on other available sub-frame of uplink.Realize the effective configuration to relay domain UE uplink retransmission, improved the configuration flexibility of relay domain UE uplink retransmission, improved HARQ retransmission efficiency, resource utilization ratio and user throughput.
Embodiment
Fig. 2 is the flow chart that the present invention realizes the method for uplink retransmission, and as shown in Figure 2, the inventive method comprises the following steps:
Step 200:RN does not correctly receive the uplink of certain relay domain UE, and this uplink is generated to NACK feedback.
Step 201:RN judge corresponding uplink retransmission subframe that system arranges whether with self uplink transmission conflict to the back haul link of eNB, if conflict enters step 202; If do not conflicted, enter step 203.
Step 202:RN collocating uplink retransmits additional indication information, and sends to NACK feedback and UL Grant information the relay domain UE that needs uplink retransmission.Enter step 204.
The additional indication information of uplink retransmission, for adjusting the position of uplink retransmission subframe, indicates corresponding relay domain UE to carry out uplink retransmission in the subframe of configuration indication.The additional indication information of uplink retransmission can be to specify a concrete sub-frame of uplink position, can be also one with respect to the side-play amount of the sub-frame of uplink position of Timing Table standard.Wherein, concrete sub-frame of uplink position can be certain sub-frame of uplink of current wireless frame, or certain sub-frame of uplink of certain radio frames after current wireless frame; Side-play amount can be sub-frame offset or sub-frame of uplink side-play amount.
The additional indication information of uplink retransmission can be an indication information that is independent of NACK feedback and UL Grant information, also can be included in UL Grant information, forms new UL Grant information format.The send mode of the additional indication information of uplink retransmission is not limited to the protection range of the inventive method, as long as the additional indication information of uplink retransmission can be sent to relay domain UE.
Specifically, uplink retransmission additional configuration information is:
Method one: the indicating means of sub-frame offset.
The additional indication information of described uplink retransmission is skew indication information s; Wherein s round numbers, and after skew adjustment, indicated re-transmission subframe is sub-frame of uplink.
Method two: the indicating means of concrete subframe.
Described uplink retransmission additional configurations indication information is specific sub-frame indication information c; Described specific sub-frame indication information c is certain sub-frame of uplink of current wireless frame, or certain sub-frame of uplink of certain radio frames after current wireless frame
Method three: sub-frame of uplink skew indicating means
Described uplink retransmission additional configurations indication information is sub-frame of uplink skew indication information t, wherein t round numbers.Method three can further reduce the expense of indication information.
Step 203:RN sends to relay domain UE by NACK feedback and UL Grant information.Specific implementation and the prior art of this step are in full accord, repeat no more here.
Further, RN also can send to corresponding relay domain UE with NACK feedback and UL Grant information by the additional indication information of uplink retransmission, and just the additional indication information of uplink retransmission is now set to without indicated value, as 0, or puts sky etc.
Step 204: relay domain UE obtains the configuration indication to uplink retransmission, and the re-transmission resource of distributing according to UL Grant information in the uplink retransmission subframe of configuration is carried out uplink retransmission.
The method of obtaining uplink retransmission subframe in this step is: if the information that relay domain UE receives only comprises nack message and UL Grant information, relay domain UE obtains uplink retransmission subframe position according to the regulation of the Timing Table of standard;
If the information receiving also comprises uplink retransmission and adds indication information, when the additional indication information of uplink retransmission is side-play amount, relay domain UE is on the basis of the uplink retransmission subframe of Timing Table defined, according to the additional indication information of uplink retransmission, adjust again, obtain the uplink retransmission subframe position of configuration indication; When the additional indication information of uplink retransmission is concrete subframe position, relay domain UE directly using the additional indication information indication of uplink retransmission sub-frame of uplink as uplink retransmission subframe.
The method one of corresponding step 202, carries out the skew of s subframe and adjusts on the basis of the n+k subframe of stipulating at the time-scale of system setting, in n+k+s subframe, the re-transmission resource that relay domain UE distributes according to ascending resource authorization message is carried out uplink retransmission.Wherein, n subframe represents the descending sub frame at ascending resource authorization message place, and k is the sub-frame interval of the ascending resource place subframe of the ascending resource authorization message place subframe that provides of time-scale and its configuration indication.
Method two in corresponding step 202, suppose relay territory UE receives NACK feedback in n subframe, corresponding UL Grant information and specific sub-frame indication information, now, relay domain UE no longer considers the sequential relationship of Timing Table defined, directly, according to the indication of specific sub-frame indication information, the re-transmission resource of distributing according to UL Grant information in indicated c subframe is carried out uplink retransmission.
Method three in corresponding step 202, on the basis of the n+k subframe of stipulating at the time-scale setting in advance, carrying out sub-frame of uplink skew adjusts, on t sub-frame of uplink after n+k subframe, the re-transmission resource that relay domain UE distributes according to ascending resource authorization message is carried out uplink retransmission.Wherein, n subframe represents the descending sub frame at ascending resource authorization message place, and k is the sub-frame interval of the ascending resource place subframe of the ascending resource authorization message place subframe that provides of time-scale and its configuration indication.
The inventive method also comprises: when described RN judges uplink retransmission subframe that system sets in advance and do not conflict to the back haul link uplink of base station with self, RN sends to relay domain UE by NACK feedback and UL authorization message, in the uplink retransmission subframe of the time-scale regulation that relay domain UE arranges in system, the re-transmission resource of distributing according to UL authorization message is carried out uplink retransmission.
Pass through the inventive method, when the sub-frame of uplink of Timing Table regulation can not carry out the re-transmission of upward signal to RN for relay domain UE, by RN indication relay domain, UE carries out uplink retransmission on other available sub-frame of uplink, realized the effective configuration to relay domain UE uplink retransmission, improve the configuration flexibility of relay domain UE uplink retransmission, improved efficiency, resource utilization ratio and user throughput that HARQ retransmits.
For the inventive method, a kind of system that realizes uplink retransmission of access link is also provided, Fig. 3 is the composition structural representation of the present invention's system of realizing uplink retransmission, as shown in Figure 3, this system comprises RN and relay domain UE, wherein,
RN, for carrying out back haul link uplink according to base station to the configuration information of RN uplink; When the sub-frame of uplink of stipulating at the time-scale of system setting can not carry out uplink retransmission to RN for relay domain UE, by uplink retransmission, add the uplink retransmission subframe position that indication information is adjusted relay domain UE, indication relay domain UE carries out uplink retransmission on other available sub-frame of uplink;
Relay domain UE, for the additional indication information of NACK feedback, ascending resource authorization message and uplink retransmission according to RN, or NACK feedback and ascending resource authorization message, obtain the indication to uplink retransmission subframe position, and the re-transmission resource of distributing according to ascending resource authorization message is carried out uplink retransmission in the uplink retransmission subframe obtaining.
RN at least comprises judging unit and processing unit, wherein,
Judging unit, for generating at RN after non-confirmation feedback, the configuration according to system to back haul link uplink, whether the corresponding uplink retransmission subframe that judges system setting exists and conflicts to the uplink of base station with self, and by judged result notifier processes unit.
Processing unit, for the uplink retransmission of the judged result configuration indication relay domain UE according to judging unit; If receive, judgment result is that and have conflict, collocating uplink retransmits additional indication information, and sends to described relay domain UE with NACK feedback and ascending resource authorization message;
If receive, judgment result is that not conflict, to described relay domain UE, send NACK feedback and ascending resource authorization message; Or the additional indication information of uplink retransmission by being configured to without indicated value, sends to described relay domain UE with NACK feedback and ascending resource authorization message.
The Timing Table shown in table 1 of take is below example, the inventive method is described in detail in conjunction with the embodiments.
Fig. 4 is the schematic diagram of the embodiment mono-of uplink retransmission configuration indication of the present invention, in embodiment mono-, using skew indication information as the additional indication information of uplink retransmission, and indication relay domain UE carries out the skew adjustment of s subframe, carries out uplink retransmission in corresponding subframe, as shown in Figure 4
Suppose under TDD configuration6 configuration, eNB configuration RN carries out Backhaul Link uplink in the #4 of m+1 radio frames subframe, and in this subframe, RN can not receive the uplink of relay domain UE.When RN is when the #9 of m radio frames subframe sends NACK feedback and UL Grant information to certain relay domain UE, by the sequential relationship k=5 of Timing Table, this UE should carry out uplink retransmission in the #4 of m+1 radio frames subframe, and this re-transmission RN cannot receive.
According to the inventive method, RN is when the #9 of m radio frames subframe sends NACK and UL Grant information to this UE, and indication UE is offset indication information s.
As shown in Figure 4, suppose s=-1, this UE skew on the basis of the #4 subframe of Timing Table regulation is adjusted in #3 subframe and to RN, is carried out uplink retransmission according to the ascending resource of UL Grant information distribution; Suppose s=4, UE carries out uplink retransmission according to the ascending resource of UL Grant information distribution to RN in the #8 of m+1 radio frames subframe.
If in the #4 of m+1 radio frames subframe, eNB does not configure RN and carries out back haul link uplink, and the uplink retransmission of this relay domain UE and the uplink of RN are without conflicting, and RN sends NACK and this uplink retransmission of UL Grant information configuration to this UE; RN also can send the additional indication information of uplink retransmission to UE, indicated value s=0 now, as shown in Figure 4.
Fig. 5 is the schematic diagram of the embodiment bis-of uplink retransmission configuration indication of the present invention, in embodiment bis-, using specific sub-frame indication information as the additional indication information of uplink retransmission, indication relay domain UE carries out uplink retransmission in certain specific c subframe, c subframe is current wireless frame certain sub-frame of uplink of certain radio frames afterwards, as shown in Figure 5.
Suppose under TDD configuration3 configuration, eNB configuration RN carries out Backhaul Link uplink in the #2 of m+1 radio frames subframe, and in this subframe, RN can not receive the uplink of relay domain UE.When RN is when the #8 of m radio frames subframe sends NACK feedback and UL Grant information to certain relay domain UE, by the sequential relationship k=4 of Timing Table, UE should carry out uplink retransmission in the #2 of m+1 radio frames subframe, and this re-transmission RN cannot receive.
According to the inventive method, RN when the #8 of m radio frames subframe sends NACK and UL Grant information to this UE in, indication UE specific sub-frame indication information c.
As shown in Figure 5, suppose c=m+1 radio frames #3 subframe, this UE, according to the indication of specific sub-frame indication information in the #3 of m+1 radio frames subframe, carries out uplink retransmission according to the ascending resource of UL Grant information distribution to RN.
Fig. 6 is the schematic diagram of embodiment tri-of the indication of uplink retransmission of the present invention, in embodiment tri-, using specific sub-frame indication information as the additional indication information of uplink retransmission, indication relay domain UE carries out uplink retransmission in certain specific c subframe, and c subframe is certain sub-frame of uplink of current wireless frame, as shown in Figure 6.
Suppose under TDD configuration0 configuration, eNB configuration RN carries out Backhaul Link uplink in the #7 of m radio frames subframe, and, in this subframe, RN can not receive the uplink of relay domain UE.When RN is when the #1 of m radio frames subframe sends NACK feedback and UL Grant information to certain relay domain UE, by the sequential relationship k=6 of Timing Table, UE should carry out uplink retransmission in the #7 of n radio frames subframe, and this re-transmission RN cannot receive.
According to the inventive method, RN also indicates UE specific sub-frame indication information c when this UE sends NACK and UL Grant information simultaneously in the #1 of m radio frames subframe.
As shown in Figure 6, suppose c=current wireless frame #9 subframe, this UE, according to the indication of specific sub-frame indication information in the #9 subframe of current wireless frame (m radio frames), carries out uplink retransmission according to the ascending resource of UL Grant information distribution to RN.
Fig. 7 is the schematic diagram of embodiment tetra-of the indication of uplink retransmission of the present invention, the sub-frame of uplink of usining in embodiment tetra-skew indication information t is as the additional indication information of uplink retransmission, on t the sub-frame of uplink of indication relay domain UE after the subframe of Timing Table regulation, carry out uplink retransmission, as shown in Figure 7.
Suppose under TDD configuration6 configuration, eNB configuration RN carries out Backhaul Link uplink in the #4 of m+1 radio frames subframe, and, in this subframe, RN can not receive the uplink of relay domain UE.When RN is when the #9 of m radio frames subframe sends NACK feedback and UL Grant information to certain relay domain UE, by the sequential relationship k=5 of Timing Table, UE should carry out uplink retransmission in the #4 of m+1 radio frames subframe, and this re-transmission RN cannot receive.
According to the inventive method, RN when the #9 of m radio frames subframe sends NACK and UL Grant information to this UE in, indication UE sub-frame of uplink skew indication information t.
As shown in Figure 7, suppose t=-1, UE skew on the basis of the #4 subframe of Timing Table regulation is adjusted in #3 subframe and to RN, is carried out uplink retransmission according to the ascending resource of UL Grant information distribution; Suppose t=1, UE carries out uplink retransmission according to the ascending resource of UL Grant information distribution to RN in the #7 of m+1 radio frames subframe.
If in the #4 of m+1 radio frames subframe, eNB does not configure RN and carries out back haul link uplink, and the uplink retransmission of this relay domain UE and the uplink of RN are without conflicting, and RN sends NACK and this uplink retransmission of UL Grant information configuration to this UE; RN also can send the additional indication information of uplink retransmission to UE, indicated value t=0 now, as shown in Figure 7.
The above, be only preferred embodiment of the present invention, is not intended to limit protection scope of the present invention, all any modifications of doing within the spirit and principles in the present invention, is equal to and replaces and improvement etc., within all should being included in protection scope of the present invention.