Summary of the invention
The invention provides the method for a kind of definite downlink transfer MCS, can not take ascending resource.
The method of a kind of definite downlink transfer MCS that the embodiment of the invention proposes comprises the steps:
The downlink transfer result of the user feedback in A, the record block error rate BLER statistical length generates the user and transmits the outcome record tabulation;
B, transmit in the outcome record tabulation content recorded according to the user and calculate Block Error Rate;
The Block Error Rate adjustment MCS that C, basis count.
Preferably, said steps A comprises:
A1, judge whether a last radio frames has received the transmission result of user feedback, as if receiving, execution in step A2 then, otherwise execution in step A4;
A2, judge whether the transmission result of the feedback receive meets statistical requirements, if meet, execution in step A3 then, otherwise execution in step A4;
A3, the transmission result of qualified feedback is inserted into the gauge outfit that the user is transmitted the outcome record tabulation, and continues execution in step A5;
A4, will transmit result " NONE " and be inserted into the gauge outfit that the user is transmitted outcome record tabulation, and continue execution in step A5.
Whether A5, the user who judges current record transmit the length of outcome record tabulation more than or equal to the BLER statistical length, if continue execution in step B, otherwise, return the transmission result that steps A 1 continues to receive next radio frames user feedback.
Preferably, steps A 5 said judged results be the user of current record transmit outcome record tabulation length greater than the BLER statistical length, then further comprise: transmit the outcome record tabulation from the user and delete being arranged in part that tail of the queue surpasses the BLER statistical length.
Preferably, said BLER statistical length=10 radio frames.
Preferably; Said user transmits that each content recorded is that a radio frames is received the transmission result of user feedback in data transmission procedure in the outcome record tabulation; Span is ACK, NACK or NONE; Wherein ACK representes the transmission success on this radio frames, and NACK representes the bust this on this radio frames, and NONE representes not transmit on this radio frames data or the feedback result received does not meet statistical requirements.
Preferably, said feedback result does not meet statistical requirements and comprises: the MCS that the corresponding transmission of feedback is used is not up-to-date adjusted MCS.
Preferably, step B is said transmits in the outcome record tabulation content recorded according to the user and calculates Block Error Rate and comprise:
Count the user and transmit that ACK in the outcome record tabulation counts ACK_NUM and NACK counts NACK_NUM;
Calculate Block Error Rate according to following formula:
Block Error Rate=NACK_NUM/ (ACK_NUM+NACK_NUM).
Preferably, the Block Error Rate adjustment MCS that counts of the said basis of step C comprises:
If the Block Error Rate that counts, then will transmit the MCS decline single order that uses more than or equal to pre-configured maximum Block Error Rate MAX_BLER;
If the Block Error Rate that counts smaller or equal to the minimum Block Error Rate MIN_BLER that is provided with in advance, then will transmit the MCS rising single order that uses;
If do not meet above situation, then keep MCS constant.
Preferably, said maximum Block Error Rate MAX_BLER=0.1.
Preferably, said minimum Block Error Rate MIN_BLER=0.
Can find out that from above technical scheme the transmission result of the user feedback that obtains according to statistics calculates Block Error Rate, MCS adjusted according to the value of Block Error Rate, the not extra uplink transmission resource that takies, and then increase the uplink capacity of system.When adjustment MCS, can reach and fall the effect that rises slowly soon, thereby guarantee that the Block Error Rate in the whole transmission course is lower, and be in the acceptable scope.It is slow that this method is applicable to that relatively channel circumstance changes, the system that terminal location is fixing.
Embodiment
The present invention program's core concept is: the base station is monitored the Block Error Rate (BLER) of downlink transfer in real time; The MCS that uses according to Block Error Rate adjustment downlink transfer then; The basic principle of adjustment is: if Block Error Rate is excessive, then reduce MCS, if Block Error Rate is too small; Then raise MCS; Thereby the MCS that transmission is used both can follow the tracks of the variation of channel circumstance, can guarantee that again transmitting Block Error Rate is in the acceptable scope, thereby made the uplink throughput of transmission approach the uplink throughput of the maximum that channel can carry as far as possible.
For making technical scheme of the present invention and effect thereof clearer, below the present invention is carried out further setting forth in detail through specific embodiment.
The technical scheme that the embodiment of the invention proposes is mainly divided two stages, and the phase I is monitoring BLER, and the another one stage is exactly to trigger the MCS that the adjustment transmission is used according to detecting the BLER that obtains.
It is as shown in Figure 1 that the embodiment of the invention proposes to fix really the method flow of row transmission MCS, comprises the steps:
Step 101: the downlink transfer result of the user feedback of record in the past period generates the user and transmits the outcome record tabulation.
The length of said time is called the BLER statistical length, and the BLER statistical length is made as can join value, and proposed arrangement is 10 radio frames.
The user transmits that each content recorded is that a radio frames is received the transmission result of user feedback in data transmission procedure in the outcome record tabulation; Span is { ACK; NACK, NONE}, wherein ACK representes the transmission success on this radio frames; NACK representes the bust this on this radio frames, and NONE representes not transmit on this radio frames data or the feedback result received does not meet statistical requirements.
In addition, the user is transmitted in the outcome record tabulation and is also disposed two amounts: acceptable maximum Block Error Rate MAX_BLER in the transmission course, suggestion value 0.1; Minimum Block Error Rate MIN_BLER, suggestion value 0.
Step 102: transmit content recorded calculating Block Error Rate in the outcome record tabulation according to the user.
Count after the user transmits ACK in the outcome record tabulation and count ACK_NUM and NACK and count NACK_NUM, calculate Block Error Rate according to following method:
Block Error Rate=NACK_NUM/ (ACK_NUM+NACK_NUM).
If the MCS that the corresponding transmission of feedback is used is not up-to-date adjusted MCS, then do not add up this feedback.More than for the regulation that does not meet statistical requirements, can make the Block Error Rate that obtains of statistics more accurate, thereby help algorithm to make the judgement of more reasonably adjusting MCS.
Step 103: according to the Block Error Rate adjustment MCS that counts.Method of adjustment is specific as follows:
If the Block Error Rate that calculates, then will transmit the MCS decline single order that uses more than or equal to MAX_BLER.
If the Block Error Rate that calculates is smaller or equal to MIN_BLER, and ACK number and NACK count sum more than or equal to the BLER statistical length, then will transmit the MCS rising single order that uses.
If do not meet above situation, then keep MCS constant.
Fig. 2 has provided the detailed implementing procedure of method of embodiment of the invention proposition downlink transfer MCS, comprises the steps:
Step 201: judge whether a last radio frames has received the transmission result of user feedback, if receive that then execution in step 202, otherwise execution in step 204.
Step 202: judge whether the feedback of receiving meets statistical requirements, if meet, then execution in step 203, otherwise execution in step 204.
In the embodiment of the invention, meet following condition then for not meeting statistical requirements: the MCS that the corresponding transmission of feedback is used is not up-to-date adjusted MCS.
Step 203: the transmission result of qualified feedback is inserted into the gauge outfit that the user is transmitted the outcome record tabulation, and continues execution in step 205.
Step 204: will transmit result " NONE " and be inserted into the gauge outfit that the user is transmitted the outcome record tabulation, and continue execution in step 205.
Step 205: whether the user who judges current record transmits the length of outcome record tabulation more than or equal to the BLER statistical length, if continue execution in step 206, otherwise, return the transmission result that step 201 continues to receive next radio frames user feedback.
If the user is transmitted the BLER statistical length that the length of outcome record tabulation has surpassed regulation, then delete from tabulation above the part of BLER statistical length being arranged in tail of the queue.
Step 206: in the tabulation of statistics of user's transmission outcome record, ACK number, NACK number and BLER in the tabulation of transmission outcome record.
Step 207: whether judge the NACK sum draw more than or equal to (BLER statistical length * MAX_BLER), if execution in step 208 then, otherwise execution in step 209.
Step 208: will transmit the MCS that uses and reduce single order, execution in step 211.
Step 209: judge whether to satisfy the condition that raises MCS, if satisfy, execution in step 210, otherwise finish this flow process.
Satisfying the condition that raises MCS is: ACK number that a last step statistics obtains and NACK count sum and observe length more than or equal to raising MCS, and BLER is less than or equal to MIN_BLER.
Step 210: will transmit the MCS rising single order that uses, and continue execution in step 211 then.
Step 211: empty the tabulation of transmission outcome record, and finish this flow process.
The present invention provides a kind of descending MCS system of selection, changes under the slower prerequisite at the channel circumstance of system, can satisfy system for the demand that the more business resource is provided as far as possible, thus the elevator system up-link capacity, and its advantage comprises:
(1) the not extra uplink transmission resource that takies, and then the uplink capacity of increase system.
(2) when adjustment MCS, can reach and fall the effect that rises slowly soon, thereby guarantee that the Block Error Rate in the whole transmission course is lower, and be in the acceptable scope.
The above is merely preferred embodiment of the present invention, and is in order to restriction the present invention, not all within spirit of the present invention and principle, any modification of being made, is equal to replacement, improvement etc., all should be included within the scope that the present invention protects.