CN101483501B - Method for adaptively regulating modulation encoding mode based on CINR - Google Patents

Abstract

The present invention provides a method for adjusting modulation coding mode based on CINR self-adaption. The method comprises the following steps: computing multi-frame average value of CINR measured values, eliminating the abnormal values of CINR measured values according to the multi-frame average value, and using the average value of residual frames after eliminating the abnormal values as CINR statistic; preventing the fluctuation of chosen modulation coding mode when the CINR statistic falls in the CINR threshold junctions corresponding to two adjacent grade modulating coding modes, wherein the modulation coding mode of each grade is respectively provided with an exit threshold CINR_THfloor which is switched to low order, a least entering threshold CINR_THin and an exit threshold CINR_THceiling that is switched to high order and the switching area between the modulation coding modes of adjacent grades; and dynamically adjusting the CINR threshold corresponding with each modulation coding mode according to the block-error rate BLER. Thereby the system stability and communication quality are ensured when the bandwidth is fully used and the spectrum efficiency is increased.

Description

A kind of method of adjusting modulation coding mode based on the CINR self adaptation

Technical field

The present invention relates to a kind of link circuit self-adapting method of adjustment in the communication system, relate in particular to a kind of method, on-the-fly modify the method for the CINR thresholding of each modulation coding mode correspondence simultaneously according to block error rate BLER (block error rate) according to carrier-in-interference noise ratio CINR (carrier-to-interference-and-noise ratio) adjustment modulation coding mode.

Background technology

In wireless communication system, channel quality is constantly to change, and the basic thought of link adaptation techniques is exactly that the basic parameter that can regulate comprises modulation system, coded system etc. according to current channel circumstance self adaptation conditioning signal transmission parameters.The gain of the system channel capacity that obtains by adaptive technique is very tangible, and this adaptive technique has been thought one of important means that improves effectively in the wireless communication system availability of frequency spectrum widely.

The principle of Adaptive Modulation and Coding strategy is exactly when channel condition is better, adopts high order modulation and high-rate coded mode, when channel condition is relatively poor, adopts low-order-modulated and low rate coding mode.The basic principle of Adaptive Modulation and Coding strategy is: define a channel quality indicator variable, i.e. and channel condition information, as: SNR, SINR or CINR etc., according to the channel condition information on time, frequency or the space, adjust the modulation coding mode of signal.The direct CINR thresholding that the CINR measured value of every frame is corresponding with current modulation coding mode of traditional Adaptive Modulation and Coding scheme (is CINR as the channel quality indicator variable) is made comparisons and is judged whether to adjust modulation coding mode, if the measurement of CINR is inaccurate or have an exceptional value, to cause the adjustment of many not right modulation coding modes, reduce the stability of system.Traditional Adaptive Modulation and Coding scheme is divided into the Lower Threshold and two of the Upper threshold that transfers high-order to that transfers low order to the CINR thresholding of each modulation coding mode correspondence, the Upper threshold of modulation coding mode N correspondence equates with the Lower Threshold of the adjacent rank modulation coding mode N+1 of higher order, if being the CINR of N and calculating, current modulation coding mode near the Upper threshold of grade N, fluctuates, because the Upper threshold of grade N equates with the Lower Threshold of N+1, then this moment, modulation coding mode will be changed between N and N+1 back and forth, thereby had also reduced the stability of system.

Traditional Adaptive Modulation and Coding scheme is a definite value by the adjustment amount that BLER on-the-fly modifies the CINR thresholding, if the relative adjustment amount of scope is very big between the last Lower Threshold of the CINR of certain modulation coding mode correspondence, it is just too slow to regulate the speed, and might reduce spectrum efficiency like this or reduce communication quality; Scope is near adjustment amount between the Lower Threshold if the CINR of certain modulation coding mode correspondence goes up, and it is just too fast to regulate the speed, and might reduce the stability of a system like this.

Therefore, need a kind of simple effective method, overcome the above shortcoming that traditional Adaptive Modulation and Coding scheme exists, when improving the general efficient of frequency, guarantee the stability of a system and communication quality.

Summary of the invention

The object of the present invention is to provide the method for a kind of simple and effective self adaptation adjustment modulation coding mode in the communication system, especially propose to adjust the method for modulation coding mode, on-the-fly modify the method for the CINR thresholding of each modulation coding mode correspondence simultaneously according to BLER based on the CINR self adaptation.

A kind of method based on CINR self adaptation adjustment modulation coding mode according to the channel quality of communication link, is dynamically adjusted modulation system and coded system, when ensuring signal quality, improves spectrum efficiency to greatest extent, it is characterized in that, comprising:

(A), calculate the multi-frame mean value of CINR measured value, according to described multi-frame mean value the exceptional value of CINR measured value is rejected, with the mean value of the residue frame after the rejecting abnormalities value as the CINR statistical value;

(B), the modulation coding mode of each grade have respectively transfer low order to withdraw from thresholding CINR_TH _Floor, minimum enters thresholding CINR_TH _InWith transfer high-order to withdraw from thresholding CINR_TH _Ceiling

If the CINR statistical value is greater than the CINR_TH of current modulation coding mode _Ceiling, then modulation coding mode is adjusted into adjacent high-grade modulation coding mode;

If the CINR statistical value is less than the CINR_TH of current modulation coding mode _Floor, and current resource satisfies the adjustment of modulation coding mode, then modulation coding mode is adjusted into adjacent inferior grade modulation coding mode; Otherwise, execution in step (C);

If the CINR statistical value is greater than CINR_TH _FloorAnd less than CINR_TH _Ceiling, execution in step (C);

(C), dynamically adjust the CINR thresholding of each modulation coding mode correspondence according to block error rate BLER.

Described step (A) specifically comprises: calculate the multi-frame mean value CINR of L frame CINR measured value, calculate the CINR measured value of each frame in the L frame and the poor Δ CINRi of described multi-frame mean value CINR, add up the symbol accumulated value of the CINR measured value of each frame in the L frame then $N_{\mathrm{sign}}=\underset{i=1}{\overset{L}{\mathrm{\Σ}}}\mathrm{Sgn}\left({\mathrm{\ΔCINR}}_i\right),$ Wherein

If 1≤i≤L wherein is N _SignAbsolute value greater than the non-negative thresholding SIGN_TH of a setting, then in the L frame, reject symbol and N _SignInconsistent frame, with the mean value CINR ' of remaining L ' frame as the CINR statistical value; If N _Sign=0, then with the multi-frame mean value CINR of L frame as the CINR statistical value.

Wherein, the CINR_TH of current modulation coding mode _CeilingCINR_TH with adjacent high-grade modulation coding mode _InEquate the CINR_TH of same hierarchical modulation coded system _InGreater than CINR_TH _Floor, there is lap in the transition region between the modulation coding mode of adjacent rank, avoids the frequent adjustment between two adjacent rank modulation coding modes.

Wherein, the step of dynamically adjusting the CINR thresholding of each modulation coding mode correspondence according to block error rate BLER comprises:

(C1), carry out the adjustment of quick CINR thresholding, the bLock error rate BLER that organizes each group successive frame in the successive frame is compared with bLock error rate short-term goal BLER_SHORT_TARGET more, statistics BLER is greater than the number of the group of BLER_SHORT_TARGET, when BLER greater than the number of the group of BLER_SHORT_TARGET when adjusting thresholding ADJUST_TH2, improve the CINR thresholding of all modulation coding modes; When BLER greater than the number of the group of BLER_SHORT_TARGET when adjusting thresholding ADJUST_TH2, transfer at a slow speed the CINR thresholding to and adjust (C2);

(C2), the adjustment of CINR thresholding is compared the block error rate BLER of continuous multiple frames with the high target BLER_HIGH_TARGET of Block Error Rate at a slow speed, if BLER greater than BLER_HIGH_TARGET, then improves the CINR thresholding; Otherwise, BLER is compared with Block Error Rate low target BLER_LOW_TARGET, if BLER less than Block Error Rate low target BLER_LOW_TARGET, then reduces the CINR thresholding; Other situations are not adjusted the CINR threshold value.

The measurement period that described quick CINR thresholding is adjusted is short, the number of the successive frame that each group of being added up is included is few, be suitable for the situation that BLER burst changes, the CINR thresholding adjustment when being used for channel quality and changing suddenly can be adjusted modulation coding mode faster according to channel variation;

The measurement period that the described thresholding of CINR is at a slow speed adjusted is long, measurement period much larger than quick CINR thresholding adjustment, be suitable for BLER and change situation stably, the CINR thresholding adjustment when being used for the channel quality smooth change can be adjusted modulation coding mode more accurately according to channel variation.

CINR statistics by steps A has overcome because the adjustment of the modulation coding mode that unusual measured value causes, three CINR thresholdings that step B is set, when having avoided the CINR statistical value to drop on the CINR thresholding intersection of adjacent rank modulation coding mode correspondence, the modulation coding mode between fluctuation of choosing, the dynamic CINR adjustment amount of step C has overcome the excessive or too small influence that modulation coding mode is regulated the speed of CINR thresholding adjustment amount, thereby when making full use of bandwidth, improving spectrum efficiency, guaranteed the stability and the communication quality of system.

Description of drawings

Fig. 1 is the method flow diagram that self adaptation of the present invention is adjusted modulation coding mode;

Fig. 2 is the flow chart of CINR threshold regulating method of the present invention;

Fig. 3 is the schematic diagram of the CINR thresholding of modulation coding mode correspondence of the present invention.

Embodiment

Further specify the specific embodiment of the present invention below in conjunction with accompanying drawing.

The invention provides the method for a kind of self adaptation adjustment modulation coding mode in the communication system, automatically adjust modulation coding mode according to the CINR statistical value, and adjust the pairing CINR thresholding of each modulation coding mode by the BLER statistical value, Fig. 1 is the flow chart that self adaptation of the present invention is adjusted modulation coding mode, and concrete steps are as follows:

The calculating of steps A, CINR statistical value:

Calculate the multi-frame mean value of CINR measured value, according to described multi-frame mean value the exceptional value of CINR measured value is rejected then, will reject the mean value of residue frame after the exceptional value as the CINR statistical value.

In order to guarantee the accuracy of CINR statistical value, the CINR measured value of multiframe (L frame) is got the multi-frame mean value, that is:

$\stackrel{\‾}{\mathrm{CINR}}=\frac{\underset{i=1}{\overset{L}{\mathrm{\Σ}}}{\mathrm{CINR}}_i}{L}.$

In order to overcome the exceptional value influence of CINR measured value, need be with abnormality value removing, symbolization criterion of the present invention is determined exceptional value, concrete grammar is: at first calculate multi-frame mean value CINR poor of each frame CINR measured value and described L frame in the L frame, that is: Δ CINR _i=CINR _i-CINR, 1≤i≤L wherein adds up the symbol accumulated value of L frame CINR measured value then $N_{\mathrm{sign}}=\underset{i=1}{\overset{L}{\mathrm{\Σ}}}\mathrm{Sgn}\left({\mathrm{\ΔCINR}}_i\right),$ Wherein

1≤i≤L wherein.

If N _SignAbsolute value greater than the non-negative thresholding SIGN_TH of a setting, then in the L frame, reject symbol and N _SignInconsistent frame, with remaining L ' (L '≤CINR threshold value that L) the mean value CINR ' of frame is corresponding with the modulation coding mode of current use makes comparisons, and carries out the adjustment of modulation coding mode subsequently;

If N _Sign=0, then that the multi-frame mean value CINR of L frame is corresponding with the modulation coding mode of current use CINR threshold value is made comparisons, and carries out the adjustment of modulation coding mode subsequently; Other situation explanation multi-frame mean values are unusual, do not carry out operation subsequently, finish this modulation coding mode adjustment.

The adjustment of step B, modulation coding mode:

The CINR threshold value that the CINR statistical value that calculates according to steps A is corresponding with presently used modulation coding mode judges whether to adjust modulation coding mode.

The division of CINR thresholding as shown in Figure 3, the modulation coding mode of each grade is corresponding respectively transfer low order to withdraw from thresholding CINR_TH _Floor, minimum enters thresholding CINR_TH _InWith transfer high-order to withdraw from thresholding CINR_TH _CeilingThree CINR thresholdings.When the CINR statistical value that calculates greater than current modulation coding mode transfer high-order to withdraw from thresholding CINR_TH _CeilingDuring value, then modulation coding mode is adjusted into adjacent high-grade decode-regulating mode by current modulation coding mode; When the CINR value that calculates less than current modulation coding mode transfer low order to withdraw from thresholding CINR_TH _FloorValue the time, then modulation coding mode is adjusted into adjacent inferior grade decode-regulating mode by current modulation coding mode, to realize the self adaptation adjustment of modulation coding mode.The CINR_TH of the modulation coding mode of grade N+1 _In ^N+1CINR_TH with the modulation coding mode of grade N _Ceiling ^NEquate the CINR_TH of the modulation coding mode of grade N+1 _Floor ^N+1Less than CINR_TH _In ^N+1

A specific embodiment of the present invention is, presently used modulation coding mode is grade N, calculate the CINR statistical value in steps A, the CINR threshold value of steps A being calculated CINR statistical value and current modulation coding mode compares, if the CINR statistical value that is calculated is greater than CINR_TH _Ceiling ^N, then modulation coding mode is adjusted into adjacent grade N+1 by grade N.After modulation coding mode is adjusted into grade N+1, even the new CINR statistical value that steps A is calculated is at CINR_TH _In ^N+1(be CINR_TH _Ceiling ^N) near among a small circle fluctuation (usually new CINR statistical value is at CINR_TH _Ceiling ^Nslightly change up and down), because ${\mathrm{CINR}\_\mathrm{TH}}_{\mathrm{floor}}^{N+1}<{\mathrm{CINR}\_\mathrm{TH}}_{\mathrm{in}}^{N+1},$ So modulation coding mode still remains N+1, and can not fluctuate between N and N+1.

Have only when the channel quality variation and make to calculate

Or channel quality improves feasible

The time just might to adjust modulation coding mode once more be N or N+2.By high-grade modulation coding mode when the conversion of adjacent inferior grade modulation coding mode, or can between two kinds of adjacent modulation coding modes, not fluctuate when the adjacent high-grade modulation coding mode conversion, thereby when improving spectrum efficiency, guaranteed the stability of system by the inferior grade modulation coding mode.

The concrete adjustment process of modulation coding mode is established the current modulation coding mode that uses and is N as shown in Figure 1, and CINR statistical value and the pairing CINR threshold value of current modulation coding mode that steps A is calculated compare, if described calculating Then in current all modulation coding modes, search and whether have modulation coding mode M (M ≠ N) makes described calculating If do not exist, explanation can't be adjusted current modulation coding mode, forwards step C to; If exist, examine current resource and can satisfy the adjustment that modulation coding mode is revised as M, if do not satisfy, explanation can't be adjusted modulation coding mode, forwards step C to; If satisfy, the modification modulation coding mode is M, and revises related resource information, finishes this Adaptive Modulation and Coding adjustment.

If described calculating $\mathrm{CINR}>{\mathrm{CINR}\_\mathrm{TH}}_{\mathrm{ceiling}}^N,$ Then in all modulation coding modes of current support, search and whether have modulation coding mode M (M ≠ N) make $\mathrm{CINR}>{\mathrm{CINR}\_\mathrm{TH}}_{\mathrm{in}}^M,$ If do not exist, the modulation coding mode that current use is described forwards step C to for the modulation coding mode of the highest ranking of the CINR that can support described calculating.If exist, the modification modulation coding mode is M, and revises related resource information, finishes this Adaptive Modulation and Coding adjustment.

If the CINR statistical value that steps A is calculated satisfies ${\mathrm{CINR}\_\mathrm{TH}}_{\mathrm{floor}}^N<\mathrm{CINR}<{\mathrm{CINR}\_\mathrm{TH}}_{\mathrm{ceiling}}^N,$ Explanation need not be adjusted current modulation coding mode, forwards step C to.

Step C, dynamically adjust the CINR thresholding of each modulation coding mode correspondence according to block error rate BLER:

CINR thresholding adjustment mode of the present invention comprises: adjustment of CINR thresholding and CINR thresholding accent fast at a slow speed.

The CINR thresholding is adjusted mode fast, the block error rate BLER of organizing each group successive frame in the successive frame is compared with Block Error Rate short-term goal BLER_SHORT_TARGET more, statistics BLER is greater than the number of the group of BLER_SHORT_TARGET, when BLER greater than the number of the group of BLER_SHORT_TARGET when adjusting thresholding, then improve the CINR thresholding; When BLER greater than the number of the group of BLER_SHORT_TARGET when adjusting thresholding, then transfer CINR thresholding adjustment at a slow speed to;

The CINR thresholding is adjusted mode at a slow speed, and the high target BLER_HIGH_TARGET of block error rate BLER and Block Error Rate of continuous multiple frames is compared, and greater than BLER_HIGH_TARGET, then improves the CINR thresholding as if BLER; Otherwise, BLER is compared with Block Error Rate low target BLER_LOW_TARGET, if BLER less than Block Error Rate low target BLER_LOW_TARGET, then reduces the CINR thresholding; Other situations are not adjusted the CINR threshold value.Wherein, BLER_LOW_TARGET＜BLER_HIGH_TARGET＜BLER_SHORT_TARGET.

In order to overcome the excessive or too small influence of regulating the speed of CINR threshold value adjustment amount to modulation coding mode, the CINR threshold value scope that the adjustment amount of CINR threshold value and currently used modulation coding mode are corresponding and reduce that still to improve thresholding relevant, the concrete adjustment process of CINR threshold value be as shown in Figure 2:

At first add up unaltered continuous frame number FRAME_NUM_TH1 of modulation coding mode and FRAME_NUM_TH2, wherein, FRAME_NUM_TH1 is continuous frame number during the CINR thresholding is adjusted at a slow speed, the measurement period of CINR thresholding adjustment mode is long at a slow speed, be suitable for BLER and change situation stably, CINR thresholding adjustment when being used for the channel quality smooth change is so that adjust modulation coding mode more accurately according to channel variation.

FRAME_NUM_TH2 is every group a continuous frame number during quick CINR thresholding is adjusted, the CINR thresholding is adjusted the measurement period weak point of mode fast, the number of the successive frame that each group of being added up is included is few, be suitable for the situation that the BLER burst changes, CINR thresholding adjustment when being used for channel quality and changing suddenly is so that comparatively fast adjust modulation coding mode according to channel variation.

According to the specific embodiment of the present invention, when the CINR thresholding was adjusted at a slow speed, FRAME_NUM_TH1 was the continuous frame number of statistics; When fast the CINR thresholding was adjusted, FRAME_NUM_TH2 was number of the included successive frame of each group, and ADJUST_TH1 is the group number of the successive frame that will add up, and ADJUST_TH2 is setting thresholding, wherein an ADJUST_TH1＞ADJUST_TH2.When the CINR thresholding is adjusted at a slow speed, in order to reflect quality of channel more accurately, need the continuous frame number of statistics abundant, therefore, FRAME_NUM_TH1＞FRAME_NUM_TH2 * ADJUST_TH1.

The BLER of each group of step (C1), calculating ADJUST_TH1 group successive frame obtains ADJUST_TH1 BLER, and wherein, each group successive frame comprises FRAME_NUM_TH2 successive frame;

Step (C2), an above-mentioned ADJUST_TH1 BLER is compared with BLER_SHORT_TARGET respectively, obtain the number short_frame_num of the group of BLER＞BLER_SHORT_TARGET, wherein, the BLER thresholding of Block Error Rate short-term goal BLER_SHORT_TARGET for setting;

Step (C3) is if short_frame_num 〉=ADJUST_TH2, the channel quality variation is described, adopt current modulation coding mode can not satisfy demand on signal quality, short_frame_num is set to 0, finish the statistics of successive frame in advance, and improving the CINR threshold value of all modulation coding mode correspondences, adjustment amount is $\frac{{\mathrm{CINR}\_\mathrm{TH}}_{\mathrm{ceiling}}-{\mathrm{CINR}\_\mathrm{TH}}_{\mathrm{floor}}}{\mathrm{RISE}\_\mathrm{CINR}\_\mathrm{TH}\_\mathrm{FACTOR}},$ Wherein, CINR_TH _Floor, CINR_TH _CeilingBe the pairing threshold value of presently used modulation coding mode, the positive integer of RISE_CINR_TH_FACTOR for setting; If short_frame_num＜ADJUST_TH2, then short_frame_num is set to 0, forwards step (C4) to;

The BLER of step (C4), FRAME_NUM_TH1 successive frame of calculating;

Step (C5), if BLER＞BLER_HIGH_TARGET, wherein, BLER_HIGH_TARGET＜BLER_SHORT_TARGET, the channel quality variation is described, adopt current modulation coding mode can not satisfy demand on signal quality, improve the CINR thresholding of each modulation coding mode correspondence, adjustment amount is $\frac{{\mathrm{CINR}\_\mathrm{TH}}_{\mathrm{ceiling}}-{\mathrm{CINR}\_\mathrm{TH}}_{\mathrm{floor}}}{\mathrm{RISE}\_\mathrm{CINR}\_\mathrm{TH}\_\mathrm{FACTOR}},$ Wherein CINR_TH is the pairing threshold value of presently used modulation coding mode, the positive integer of RISE_CINR_TH_FACTOR for setting; Otherwise, execution in step (C6);

Step (C6), if BLER＜BLER_LOW_TARGET, wherein, BLER_LOW_TARGET＜BLER_HIGH_TARGET＜BLER_SHORT_TARGET, illustrate that channel quality improves, in order effectively to utilize bandwidth, reduce the CINR thresholding of each modulation coding mode correspondence, adjustment amount is $\frac{{\mathrm{CINR}\_\mathrm{TH}}_{\mathrm{floor}}-{\mathrm{CINR}\_\mathrm{TH}}_{\mathrm{ceiling}}}{\mathrm{LOWER}\_\mathrm{CINR}\_\mathrm{TH}\_\mathrm{FACTOR}},$ Wherein CINR_TH is the pairing threshold value of presently used modulation coding mode, and LOWER_CINR_TH_FACTOR is a positive integer and greater than RISE_CINR_TH_FACTOR.

Step (C7), other situations are not adjusted the CINR threshold value.

The Adaptive Modulation and Coding scheme that the present invention proposes, amount of calculation is little, and is effectively simple, can adjust modulation and coded system neatly according to the link channel quality, when ensuring signal quality, improves spectrum efficiency to greatest extent.

Claims (4)

1. the method based on CINR self adaptation adjustment modulation coding mode according to the channel quality of communication link, is dynamically adjusted modulation system and coded system, when ensuring signal quality, improves spectrum efficiency to greatest extent, it is characterized in that, comprising:

(A), calculate the multi-frame mean value of CINR measured value, according to described multi-frame mean value the exceptional value of CINR measured value is rejected, with the mean value of the residue frame after the rejecting abnormalities value as the CINR statistical value;

(B), the modulation coding mode of each grade have respectively transfer low order to withdraw from thresholding CINR_TH _Floor, minimum enters thresholding CINR_TH _InWith transfer high-order to withdraw from thresholding CINR_TH _Ceiling

If the CINR statistical value is greater than the CINR_TH of current modulation coding mode _Ceiling, then modulation coding mode is adjusted into adjacent high-grade modulation coding mode;

If the CINR statistical value is less than the CINR_TH of current modulation coding mode _Floor, and current resource satisfies the adjustment of modulation coding mode, then modulation coding mode is adjusted into adjacent inferior grade modulation coding mode; Otherwise, execution in step (C);

If the CINR statistical value is more than or equal to CINR_TH _FloorAnd smaller or equal to CINR_TH _Ceiling, execution in step (C);

(C), dynamically adjust the CINR thresholding of each modulation coding mode correspondence according to block error rate BLER;

Wherein, according to described multi-frame mean value the exceptional value of CINR measured value is rejected and be specially: the multi-frame mean value of at first calculating each frame CINR measured value and described L frame in the L frame

Poor, that is:

1≤i≤L wherein adds up the symbol accumulated value of L frame CINR measured value then

Wherein 1≤i≤L wherein;

If N _SignAbsolute value greater than the non-negative thresholding SIGN_TH of a setting, then in the L frame, reject symbol and N _SignInconsistent frame, with remaining L ' (L '≤L) mean value of frame

The CINR threshold value corresponding with the modulation coding mode of current use made comparisons, and carries out the adjustment of modulation coding mode subsequently;

If N _Sign=0, then with the multi-frame mean value of L frame The CINR threshold value corresponding with the modulation coding mode of current use made comparisons, and carries out the adjustment of modulation coding mode subsequently; Other situation explanation multi-frame mean values are unusual, do not carry out operation subsequently, finish this modulation coding mode adjustment.

2. method according to claim 1 is characterized in that: the CINR_TH of current modulation coding mode _CeilingCINR_TH with adjacent high-grade modulation coding mode _InEquate that the thresholding of same hierarchical modulation coded system closes and is: CINR_TH _Ceiling＞CINR_TH _In＞CINR_TH _Floor, there is lap in the transition region between the modulation coding mode of adjacent rank, avoids the frequent adjustment between two adjacent rank modulation coding modes.

3. method according to claim 1 is characterized in that, the step of dynamically adjusting the CINR thresholding of each modulation coding mode correspondence according to block error rate BLER comprises:

(C1), carry out the adjustment of quick CINR thresholding, the block error rate BLER of organizing each group successive frame in the successive frame is compared with Block Error Rate short-term goal BLER_SHORT_TARGET more, statistics BLER is greater than the number of the group of BLER_SHORT_TARGET, when BLER greater than the number of the group of BLER_SHORT_TARGET when adjusting thresholding ADJUST_TH2, improve the CINR thresholding of all modulation coding modes; When BLER greater than the number of the group of BLER_SHORT_TARGET when adjusting thresholding ADJUST_TH2, transfer at a slow speed the CINR thresholding to and adjust (C2);

(C2), the adjustment of CINR thresholding is compared the block error rate BLER of continuous multiple frames with the high target BLER_HIGH_TARGET of Block Error Rate at a slow speed, if BLER greater than BLER_HIGH_TARGET, then improves the CINR thresholding; Otherwise, BLER is compared with Block Error Rate low target BLER_LOW_TARGET, if BLER less than Block Error Rate low target BLER_LOW_TARGET, then reduces the CINR thresholding; Other situations are not adjusted the CINR threshold value.

4. method according to claim 3 is characterized in that,

The measurement period that described quick CINR thresholding is adjusted is short, the number of the successive frame that each group of being added up is included is few, be suitable for the situation that BLER burst changes, the CINR thresholding adjustment when being used for channel quality and changing suddenly can be adjusted modulation coding mode faster according to channel variation;

The measurement period that the described thresholding of CINR is at a slow speed adjusted is long, measurement period much larger than quick CINR thresholding adjustment, be suitable for BLER and change situation stably, the CINR thresholding adjustment when being used for the channel quality smooth change can be adjusted modulation coding mode more accurately according to channel variation.

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