CN1190091C - Dynamic channel allocation combined data retransmitting method in time-division duplex system - Google Patents
Dynamic channel allocation combined data retransmitting method in time-division duplex system Download PDFInfo
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- CN1190091C CN1190091C CN 02116409 CN02116409A CN1190091C CN 1190091 C CN1190091 C CN 1190091C CN 02116409 CN02116409 CN 02116409 CN 02116409 A CN02116409 A CN 02116409A CN 1190091 C CN1190091 C CN 1190091C
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Abstract
The present invention discloses a data retransmitting method with the combination of dynamic channel allocation in a time division duplex system. The present invention comprises steps that (a) a base station transmits a new downlink data packet according to a currently given channel priority; (b) a mobile station carries out circulation redundancy check on the received data packet and measures the quality of a downlink channel; when the check result is correct, the priority of a current channel is increased, and the step a is returned to; when the check result is not correct, the check result and the measured quality value of the downlink channel are sent to the base station; after the reception of the base station, the base station determines whether the transmission mistake of the data packet is caused by the channel; when the transmission fault of the data packet is not caused by the channel, the current channel retransmits a data block which is mistakenly transmitted, and the step b is returned to; when the transmission fault of the data packet is caused by the channel, the priority of the current channel is decreased, the base station allocates an idle channel with high priority to a user again, or the original channel retransmits the data block which is mistakenly transmitted, and the step b is returned to. When the method is used, nonstop retransmission caused by a channel reason can be avoided, and the correctness of the new transmission of data is also ensured; consequently, the system efficiency is increased.
Description
Technical field
The present invention relates to a kind of data re-transmission technology that is applicable to tdd systems, be meant especially a kind of in tdd systems the data repeating method in conjunction with dynamic channel allocation.
Background of invention
In 3G (Third Generation) Moblie (3G) system, fast development along with internet (Internet), people are to inserting Internet whenever and wherever possible, and the demand of high-speed downloads mass data is increasing from network, and the business demand of wireless high-speed data transmission also increases rapidly thereupon.Simultaneously, the enhancing of 3G agreement makes it to support higher message transmission rate to become and presses for.But, because channel condition is comparatively complicated, phenomenons such as data-bag lost and biography mistake can appear in the transmission course, require this moment the re-transmission of this packet just very necessary.
At present, the method of a kind of automatic repeat requests of mixing (HARQ) has been proposed for retransmission mechanism, its principle is exactly: H-ARQ carries out cyclic redundancy school inspection (CRC) at receiving terminal to decoded information, the result of verification feeds back to transmitting terminal, the information that transmitting terminal is made mistakes to CRC check retransmits, the information that retransmits refers generally to redundant information, decides according to the H-ARQ mode is different.H-ARQ also is a kind of link adaptation techniques, can represent the operation principle of HARQ technology with Fig. 1.Among Fig. 1, suppose that A and B represent two users respectively, A11 is the transmission first time of a certain data block of party A-subscriber, because transmitting terminal is received error of transmission sign NACK (A), therefore this data block is retransmitted, and A12 promptly represents the transmission second time of this data block; In like manner, B11 is the transmission first time of a certain data block of party B-subscriber, because transmitting terminal is received error of transmission sign NACK (B), therefore this data block is retransmitted, B12 promptly represents the transmission second time of this data block, receives error of transmission sign NACK (B) again after the transmission for the second time, so this data block is retransmitted again, B13 promptly represents the transmission for the third time of this data block, receive ACK (B) after, transmit B21 the first time that the party B-subscriber just begins another data block.
In above-mentioned transfer of data and retransmission processes, if owing to the reason of channel itself, such as: current channel condition extreme difference and can't recover, so, just might cause the undying re-transmission of data, not only waste system resource, reduce system effectiveness, and can because data can not correctly transmit and cause the whole system can't operate as normal.But, also do not relate to how in retransmission processes, what to redistribute channel according in the prior art, with and available distribution method.
Summary of the invention
In order to improve the capacity of system, usually without exception employing channel reuse technology in the wireless communication system of sub-district system, be dynamic channel allocation (DCA) technology, utilize limited channel resource efficiently, can provide user as much as possible to insert is the purpose of channel allocation technique.So, when causing data re-transmission,, will solve the data that the channel reason causes effectively and ceaselessly retransmit, improve the accuracy of transfer of data if can be reasonably in conjunction with dynamic channel allocation and data re-transmission technology owing to the channel reason.
In view of this, main purpose of the present invention be to provide a kind of in tdd systems the data repeating method in conjunction with dynamic channel allocation, make it can avoid the re-transmission ceaselessly that causes owing to the channel reason, simultaneously the correctness that data are transmitted again be can guarantee, thereby efficient, stability, reliability and the accuracy of system improved.
For achieving the above object, technical scheme of the present invention specifically is achieved in that
A kind of in tdd systems in conjunction with the data repeating method of dynamic channel allocation, it comprises the steps: at least
A. the base station is by new downlink data packet of current given channel priority transmission;
B. travelling carriage carries out the quality that the cyclic redundancy school is examined (CRC) and measured down channel to the packet that receives, if check results is correct, then increases the priority of current channel, returns step a; Otherwise, check results and the down channel quality value that records are delivered to the base station, enter step c;
C. after check results and down channel quality value are received in the base station, judge whether because channel causes the data packet transmission mistake, if not, then retransmit the wrong data block of this biography with current channel, return step b; If, then reduce the priority of current channel, judge whether the channel priority after reducing equals the channel priority lower limit, if equal, then the base station retransmits the data block of this biography mistake for this user distributes a high idle channel of priority again; If be not equal to, then whether redistribute channel according to this number of retransmissions decision that passes wrong data block, return step b.
In this method, step b further comprises: when check results was correct, travelling carriage was delivered to the base station with this check results; After receive the base station, the priority of current channel is added 1, judges then whether the new priority of current channel equals the channel priority upper limit, if equal, then with the new priority of current channel divided by 2, return step a; If less than, then directly return step a.
Judge whether among the step c because channel causes the data packet transmission mistake further to comprise:
C11. after check results is received in the base station, measure the quality of up channel earlier;
C12. calculate the measured value after this up channel weighting then, wherein, the measured value after this channel weights be uplink signal-channel quality value and down channel quality value be multiplied by respectively behind weighted factor, the β and, and this weighted factor and β sum are 1;
Whether the absolute value of difference of c13. judging measured value after this up channel weighting and benchmark signal interference ratio reference value again more than or equal to the thresholding difference of judging channel quality, if more than or equal to, then be to cause the data packet transmission mistake, otherwise be not by channel.
In step c, if cause the data packet transmission mistake by the channel reason, then the base station subtracts 1 with the priority of current channel.
Channel priority after reducing is not equal under the channel priority prescribes a time limit, step c further comprises: the base station judges whether this number of retransmissions that passes wrong data block equals predefined retransmission threshold value, if equal, then the base station is chosen an idle channel that priority is the highest and is retransmitted the wrong data block of this biography from the current channel priority table of this user; Otherwise, continue to retransmit the wrong data block of this biography with current channel.In such cases, need the base station to preestablish the retransmission threshold value that passes wrong data block.
Channel priority after reducing is not equal under the channel priority prescribes a time limit, step c also can further comprise: travelling carriage judges whether this number of retransmissions that passes wrong data block equals predefined retransmission threshold value, if equal, then send request and change channel massage to the base station, after receive the base station, from the current channel priority table of this user, choose an idle channel that priority is the highest and retransmit the wrong data block of this biography; Otherwise, continue to retransmit the wrong data block of this biography with current channel.In such cases, travelling carriage will preestablish the retransmission threshold value that passes wrong data block.
This method also needs to preestablish the thresholding difference of the channel priority upper limit, channel priority lower limit and judgement channel quality, and the channel that offers base station node B according to the current channel quality and the radio network controller (RNC) of reporting of user, the base station is provided with a channel priority table for each user in advance.Wherein, the higher limit of channel priority be 2 index doubly.
By such scheme as can be seen, key of the present invention is: whether system judges that according to channel quality needs change transmission channel when the data re-transmission, to improve the accuracy of transfer of data, avoid the re-transmission ceaselessly that causes owing to the channel reason, and then improve the system transmissions quality.
Therefore, provided by the present invention in tdd systems in conjunction with the data repeating method of dynamic channel allocation, by the estimation of channel quality being judged the erroneous transmissions that whether has caused packet owing to the reason of channel, if the channel reason causes the data packet transmission mistake, redistribute an idle channel that channel condition is good then for this user; If not the reason of channel condition, then need not redistribute channel, and continue to use original channel to carry out the re-transmission of packet.This method can be avoided causing undying re-transmission owing to the reason of bad channel quality on the one hand, reduces resource waste; Also can improve the accuracy of data re-transmission on the other hand, thereby improve systematic function and efficient, the stability of enhanced system, reliability and validity are guaranteed the normal operation of system.
Description of drawings
Fig. 1 is for mixing the principle schematic of automatic repeat requests operator scheme one example;
The particular flow sheet that Fig. 2 realizes for the inventive method.
Embodiment
The present invention is further described in more detail below in conjunction with drawings and the specific embodiments.
The prerequisite that the present invention realizes is: suppose that this wireless communication system adopts the time division duplex technology and uses dynamic channel allocating technology in order, and this system supports retransmission mechanism.Preestablish following parameter simultaneously:
1) Uphold is the upper limit of channel priority, and this value should be set at 2 index doubly, so that represented by bit, such as being made as 16,32,64,128,256 or the like, establishes Uphold=256 in the present embodiment;
2) Downhold is the lower limit of channel priority, establishes Downhold=0 in the present embodiment;
3) SIR
DownThe signal interference ratio of the down channel that the expression mobile station side is estimated;
4) SIR
OnThe signal interference ratio of the up channel that expression base station node B side is estimated;
5) SIR
EstThe signal interference ratio of the received signal that the weighting of expression base station side forms, SIR
EstIn weighted factor, the β value used are approaching more can reflect quality of channel more, α=β=0.5 is established in and alpha+beta=1 in the present embodiment;
6) SIR
TarExpression radio network controller (RNC) calculates the external ring power control target signal interference ratio of gained, and RNC calculates resulting CRC check result to its each base station of administering to carry out grand diversity and merge and draw.Because it is very slow that this value changes, and can be used as benchmark signal interference ratio reference value.Wherein, outer shroud is meant the loop between base station and the mobile switching centre;
7) Threshold is for judging the thresholding difference of channel quality, and present embodiment is established Threshold=5dB;
8) ACK/NACK be subscriber equipment (UE) end after CRC check, the sign whether transmission of the bag of feedback successful, ACK represents success, NACK represents to fail.
9) n is for to retransmit the number of times that certain passes wrong data block with current channel, and initial value is made as 0; N passes the retransmission threshold value of wrong data block for this, and this N value is passed to the base station under determining by system is high-rise.
Referring to shown in Figure 2, the specific implementation of data repeating method of the present invention may further comprise the steps at least:
(1) new downlink data packet P1 of base station transmits, and n=0 is set.
(2) travelling carriage carries out CRC check to the packet P1 that receives, and measures the quality SIR of down channel
Down=a.If current check results to data block is ACK, then ACK is sent to the base station, enter step 3); If current check results to data block is NACK, then with NACK and down channel quality SIR
DownBe sent to the base station, enter step 4).
(3) after the base station receives ACK information, the priority of this channel is added 1, it is new priority=former priority+1, and judge whether this new priority equals 256, if equal, then with priority 2 56 divided by 2, obtain new priority=128 of this channel, return step 1) with the new data block of new priority 1 28 transmission; If less than, then directly return step 1) with the new data block of new priority transmission.
(4) after the base station receives nack message, at first need to measure the quality of up channel, record SIR
On=b, the measured value with the uplink and downlink channel quality is weighted merging by following formula then, obtains the measured value SIR of this moment after this channel weights
Est:
SIR
est＝0.5×a+0.5×b
Need to judge whether channel is the reason that causes the data packet transmission mistake this moment:
If 1. | SIR
Est-SIR
Tar| 〉=5dB, illustrate that channel quality is the main cause that makes the mistake and transmit, because the current signal interference ratio of channel can demonstrate fully the current quality condition of this channel, so, subtract 1 with the priority of this channel this moment earlier, be new priority=former priority-1, while n=n+1, whether the new priority of judging channel then equals Downhold=0, if equal, then the base station is given priority that is higher than the priority lower limit of this channel allocation again, such as: make Downhold=64, the base station is therefrom selected the according to priority unified ordering of the available free channel in the current channel priority table of this user an idle channel that priority is the highest again and is redistributed to this user afterwards, and retransmit the wrong data block of this biography, and put n=0 with new channel; If new priority is not equal to Downhold, judge then whether this error block retransmits N time, if not, then continue to retransmit the wrong data block of this biography with current channel, otherwise, illustrate that the condition of current channel has been unsuitable for transmitting data again, then the base station is with the according to priority unified ordering of the available free channel in the current channel priority table of this user, therefrom select an idle channel that priority is the highest and redistribute, and retransmit the wrong data block of this biography with new channel to this user.
Because the transmission of channel quality problems affect data block in the time of need redistributing channel, can also decide when change channel by travelling carriage, specific implementation is such when being confirmed to be: set the count value n that a recording data blocks retransmits at travelling carriage in advance
UEAnd threshold value N
UE, n of every re-transmission
UEAdd 1.So, if | SIR
Est-SIR
Tar| 〉=5dB, then the priority with this channel subtracts 1, simultaneously mobile station side n
UE=n
UE+ 1, whether the new priority of judging channel then equals Downhold=0, if equal, then the base station is given priority that is higher than the priority lower limit of this channel allocation again, the base station is with the according to priority unified ordering of the available free channel in the current channel priority table of this user afterwards, therefrom select an idle channel that priority is the highest again and redistribute, and retransmit the wrong data block of this biography with new channel to this user, and travelling carriage side n
UE=0; If new priority is not equal to Downhold, then travelling carriage judges whether this error block has retransmitted N
UEInferior, if not, then continue to retransmit the wrong data block of this biography with current channel, otherwise, travelling carriage is sent out the replacing channel request to the base station, from the current channel priority table of this user, select an idle channel that priority is the highest after receive the base station and redistribute, and retransmit the wrong data block of this biography with new channel to this user.
If 2. channel quality is better, promptly | SIR
Est-SIR
Tar|＜5dB, illustrate that channel quality is not the main cause that causes the packet error transmission, needn't redistribute channel this moment, and the priority of this channel is also constant, promptly continues to use former channel to retransmit the wrong data block of this biography.
Return step 2) handle.
In above-mentioned processing procedure, all can set in advance a channel priority table for each user, comprise in the table that the current available channel of this user and each channel corresponding priorities are other, this channel priority table is to determine jointly according to the channel that the current channel quality of reporting of user and RNC offer Node B.Wherein, the priority initial value of each channel is decided at random by the base station, the initial priority of each channel is essentially identical, can be made as the mean value of Uphold and Downhold earlier, the situation of quality situation that reports along with UE and RNC feedback is carried out the rearrangement of channel at the channel priority table of each UE then.
For the maintenance of channel priority table, RNC can constantly notify each base station, present operable channel, and the renewal of channel priority table is carried out in the base station according to this information.Each user of while is in the idle measure channel quality constantly that does not pass data and send the base station to, is used for the renewal and the maintenance of channel priority table equally.Therefore, when the data retransmission selective channel, just do not need, and the direct selection of finishing channel by Node B on time delay, can be complementary with retransmission delay time fully by RNC.
As can be seen, the present invention judges according to channel quality whether needs change channel transmitted when retransmitting, when needs change transmission channel, adopt dynamic channel assignment method to carry out the selection of retransfer channel, that is: the base station is distributed the high channel of priority of a free time preferentially to be used for transmitting from the channel priority table that is provided with for each user in advance to finish data re-transmission.So, can guarantee when current channel condition is bad, to use better channel that the data block of erroneous transmissions is retransmitted the re-transmission ceaselessly that so not only can avoid the reason owing to bad channel quality to cause, and can guarantee the correctness of transfer of data, thereby improve the efficient of system.
Claims (12)
1, a kind of in tdd systems in conjunction with the data repeating method of dynamic channel allocation, it is characterized in that comprising the steps: at least
A. the base station is by new downlink data packet of current given channel priority transmission;
B. travelling carriage carries out the quality that the cyclic redundancy school is examined CRC and measured down channel to the packet that receives, if check results is correct, then increases the priority of current channel, returns step a; Otherwise, check results and the down channel quality value that records are delivered to the base station, enter step c;
C. after check results and down channel quality value are received in the base station, judge whether because channel causes the data packet transmission mistake, if not, then retransmit the wrong data block of this biography with current channel, return step b; If, then reduce the priority of current channel, judge whether the channel priority after reducing equals the channel priority lower limit, if equal, then the base station retransmits the data block of this biography mistake for this user distributes a high idle channel of priority again; If be not equal to, then whether redistribute channel according to this number of retransmissions decision that passes wrong data block, return step b.
2, data repeating method according to claim 1, it is characterized in that step b further comprises: when check results was correct, travelling carriage was delivered to the base station with this check results; After receive the base station, the priority of current channel is added 1, judges then whether the new priority of current channel equals the channel priority upper limit, if equal, then with the new priority of current channel divided by 2, return step a; If less than, then directly return step a.
3, data repeating method according to claim 1 is characterized in that judging whether among the step c because channel causes the data packet transmission mistake further to comprise:
C11. after check results is received in the base station, measure the quality of up channel earlier;
C12. calculate the measured value after this up channel weighting then;
Whether the absolute value of difference of c13. judging measured value after this up channel weighting and benchmark signal interference ratio reference value again more than or equal to the thresholding difference of judging channel quality, if more than or equal to, then be to cause the data packet transmission mistake, otherwise be not by channel.
4, data repeating method according to claim 1, it is characterized in that step c further comprises: if cause the data packet transmission mistake by the channel reason, then the base station subtracts 1 with the priority of current channel.
5, data repeating method according to claim 1, it is characterized in that step c further comprises: the channel priority after reducing is not equal under the channel priority prescribes a time limit, the base station judges whether this number of retransmissions that passes wrong data block equals predefined retransmission threshold value, if equal, then the base station is chosen an idle channel that priority is the highest and is retransmitted the wrong data block of this biography from the current channel priority table of this user; Otherwise, continue to retransmit the wrong data block of this biography with current channel.
6, data repeating method according to claim 5 is characterized in that this method comprises that further the base station preestablishes the retransmission threshold value that passes wrong data block.
7, data repeating method according to claim 1, it is characterized in that step c further comprises: the channel priority after reducing is not equal under the channel priority prescribes a time limit, travelling carriage judges whether this number of retransmissions that passes wrong data block equals predefined retransmission threshold value, if equal, then send request and change channel massage to the base station, after receive the base station, from the current channel priority table of this user, choose an idle channel that priority is the highest and retransmit the wrong data block of this biography; Otherwise, continue to retransmit the wrong data block of this biography with current channel.
8, data repeating method according to claim 7 is characterized in that this method further is included in travelling carriage and preestablishes the retransmission threshold value that passes wrong data block.
9, data repeating method according to claim 1 and 2 is characterized in that this method further comprises: the thresholding difference that preestablishes the channel priority upper limit, channel priority lower limit and judge channel quality.
10, data repeating method according to claim 9 is characterized in that: the higher limit of setting channel priority be 2 index doubly.
11, data repeating method according to claim 1, it is characterized in that this method further comprises: according to the channel that the current channel quality and the radio network controller (RNC) of reporting of user offers the base station, the base station is provided with a channel priority table for each user in advance.
12, method according to claim 3 is characterized in that: set measured value after this channel weights and be uplink signal-channel quality value and down channel quality value be multiplied by respectively behind weighted factor, the β and, and set this weighted factor and the β sum is 1.
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| Application Number | Priority Date | Filing Date | Title |
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| CN 02116409 CN1190091C (en) | 2002-04-02 | 2002-04-02 | Dynamic channel allocation combined data retransmitting method in time-division duplex system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02116409 CN1190091C (en) | 2002-04-02 | 2002-04-02 | Dynamic channel allocation combined data retransmitting method in time-division duplex system |
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| CN1449206A CN1449206A (en) | 2003-10-15 |
| CN1190091C true CN1190091C (en) | 2005-02-16 |
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| CN100358388C (en) * | 2004-03-04 | 2007-12-26 | Ut斯达康通讯有限公司 | Dynamic channel distributing method |
| CN101615972B (en) * | 2008-06-25 | 2013-10-09 | 华为技术有限公司 | Methods and devices for rank check and rank mask as well as communication system |
| CN102256364A (en) * | 2010-05-18 | 2011-11-23 | 中兴通讯股份有限公司 | Channel distribution method, apparatus and system thereof |
| US11005635B2 (en) | 2015-09-22 | 2021-05-11 | Qualcomm Incorporated | Reliable channel assisted hybrid-arq |
| CN113873674A (en) | 2015-11-05 | 2021-12-31 | 索尼公司 | Electronic device in wireless communication system and method for wireless communication |
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