Summary of the invention
In order to improve the precision that CQI revises, especially under the less situation of sample size, improve the precision that CQI revises, the embodiment of the invention provides a kind of method and apparatus of channel quality indication (CQI) information correction.Described technical scheme is as follows:
The method of a kind of channel quality indicator (CQI) information correction, described method comprises:
After first moment got access to a CQI information, calculate described corresponding accumulation CQI adjustment amount of first moment;
After second moment got access to the 2nd CQI information, calculate described first constantly and the cycle accumulative total CQI adjustment amount between described second moment;
With described first constantly corresponding accumulation CQI adjustment amount multiply by corresponding first confidence level and add up with accumulative total CQI of described cycle adjustment amount, obtain the described second accumulation CQI adjustment amount of correspondence constantly;
With described second constantly corresponding accumulation CQI adjustment amount multiply by corresponding second confidence level and described the 2nd CQI information adds up, obtain revised the 2nd CQI information.
Wherein, the cycle accumulative total CQI adjustment amount between described first moment of described calculating and described second moment comprises:
According to described first constantly and described second each period of the day from 11 p.m. to 1 a.m between constantly carve carve with its last period of the day from 11 p.m. to 1 a.m between data block transmitted correct and accumulation Block Error Rate that described data block is corresponding whether, calculates CQI adjustment amount of described each period of the day from 11 p.m. to 1 a.m correspondence at quarter;
Described each period of the day from 11 p.m. to 1 a.m is carved corresponding CQI adjustment amount add up, obtain described cycle accumulative total CQI adjustment amount.
Wherein, described according to described first constantly and described second each period of the day from 11 p.m. to 1 a.m between constantly carve carve with its last period of the day from 11 p.m. to 1 a.m between data block transmitted correct and accumulation Block Error Rate that described data block is corresponding whether, the CQI adjustment amount that calculates described each period of the day from 11 p.m. to 1 a.m correspondence at quarter comprises:
When described each period of the day from 11 p.m. to 1 a.m carves with its last period of the day from 11 p.m. to 1 a.m that data block transmitted is correct between quarter, if the accumulation Block Error Rate of described data block correspondence is between presetting first threshold and second threshold value time, it is a preset positive value that described each period of the day from 11 p.m. to 1 a.m corresponding CQI adjustment amount at quarter is set, if the accumulation Block Error Rate of described data block correspondence not between described first threshold and described second threshold value time, arranges described each period of the day from 11 p.m. to 1 a.m and carves corresponding CQI adjustment amount greater than described preset positive value;
When described each period of the day from 11 p.m. to 1 a.m is carved with its last period of the day from 11 p.m. to 1 a.m between quarter during the data block transmitted mistake, if the accumulation Block Error Rate of described data block correspondence is between presetting first threshold and second threshold value time, it is a preset negative value that described each period of the day from 11 p.m. to 1 a.m corresponding CQI adjustment amount at quarter is set, if the accumulation Block Error Rate of described data block correspondence not between described first threshold and described second threshold value time, arranges described each period of the day from 11 p.m. to 1 a.m and carves corresponding CQI adjustment amount less than described preset negative value.
Wherein, described calculating described first comprises constantly and after the cycle accumulative total CQI adjustment amount between described second moment:
If described cycle accumulative total CQI adjustment amount is greater than the first default upper limit, it is described first upper limit that described cycle accumulative total CQI adjustment amount is set;
If described cycle accumulative total CQI adjustment amount is less than the first default lower limit, it is described first lower limit that described cycle accumulative total CQI adjustment amount is set.
Wherein, the described accumulation CQI adjustment amount that obtains described second moment correspondence comprises afterwards:
With the zero clearing of described cycle accumulative total CQI adjustment amount.
Wherein, a described CQI information is that a CQI value, described the 2nd CQI information are that the 2nd CQI value, described accumulation CQI adjustment amount are cycle accumulative total CQI increment for accumulating CQI increment and described cycle accumulative total CQI adjustment amount; Perhaps,
A described CQI information is that a CQI value corresponding spectrum efficiency increment, described the 2nd CQI information are that the corresponding spectrum efficiency increment of the 2nd CQI value, described accumulation CQI adjustment amount are cycle accumulative total spectrum efficiency increment for accumulating spectrum efficiency increment and described cycle accumulative total CQI adjustment amount.
The device of a kind of channel quality indicator (CQI) information correction, described device comprises:
The accumulation module is used for after first moment got access to a CQI information, obtains described corresponding accumulation CQI adjustment amount of first moment;
Computing module is used for after second moment got access to the 2nd CQI information, calculates described first constantly and the cycle accumulative total CQI adjustment amount between described second moment;
Accumulator module, be used for described accumulation module obtain first constantly corresponding accumulation CQI adjustment amount multiply by corresponding first confidence level and add up with the cycle accumulative total CQI adjustment amount that described computing module obtains, obtain the described second accumulation CQI adjustment amount of correspondence constantly;
Correcting module, be used for described accumulator module obtain second constantly corresponding accumulation CQI adjustment amount multiply by the 2nd CQI information that corresponding second confidence level and described computing module obtain and add up, obtain revised the 2nd CQI information.
Wherein, described computing module comprises:
Computing unit, be used for according to described first constantly and described second each period of the day from 11 p.m. to 1 a.m between constantly carve carve with its last period of the day from 11 p.m. to 1 a.m between data block transmitted correct and accumulation Block Error Rate that described data block is corresponding whether, calculates CQI adjustment amount of described each period of the day from 11 p.m. to 1 a.m correspondence at quarter;
The unit that adds up, each period of the day from 11 p.m. to 1 a.m that is used for described computing unit is obtained is carved corresponding CQI adjustment amount and is added up, and obtains described cycle accumulative total CQI adjustment amount.
Wherein, described computing unit comprises:
First computing unit, be used for carving and its last period of the day from 11 p.m. to 1 a.m when data block transmitted is correct between quarter when described each period of the day from 11 p.m. to 1 a.m, if the accumulation Block Error Rate of described data block correspondence is between presetting first threshold and second threshold value time, it is a preset positive value that described each period of the day from 11 p.m. to 1 a.m corresponding CQI adjustment amount at quarter is set, if the accumulation Block Error Rate of described data block correspondence not between described first threshold and described second threshold value time, arranges described each period of the day from 11 p.m. to 1 a.m and carves corresponding CQI adjustment amount greater than described preset positive value;
Second computing unit, be used for carving and its last period of the day from 11 p.m. to 1 a.m between quarter during the data block transmitted mistake when described each period of the day from 11 p.m. to 1 a.m, if the accumulation Block Error Rate of described data block correspondence is between presetting first threshold and second threshold value time, it is a preset negative value that described each period of the day from 11 p.m. to 1 a.m corresponding CQI adjustment amount at quarter is set, if the accumulation Block Error Rate of described data block correspondence not between described first threshold and described second threshold value time, arranges described each period of the day from 11 p.m. to 1 a.m and carves corresponding CQI adjustment amount less than described preset negative value.
Wherein, described computing module, if also be used for described cycle accumulative total CQI adjustment amount greater than the first default upper limit, it is described first upper limit that described cycle accumulative total CQI adjustment amount is set;
If described cycle accumulative total CQI adjustment amount is less than the first default lower limit, it is described first lower limit that described cycle accumulative total CQI adjustment amount is set.
Wherein, described device also comprises: dump block, and after being used for carrying out the function of described accumulator module, with the zero clearing of described cycle accumulative total CQI adjustment amount.
Wherein, a described CQI information is that a CQI value, described the 2nd CQI information are that the 2nd CQI value, described accumulation CQI adjustment amount are cycle accumulative total CQI increment for accumulating CQI increment and described cycle accumulative total CQI adjustment amount; Perhaps,
A described CQI information is that a CQI value corresponding spectrum efficiency increment, described the 2nd CQI information are that the corresponding spectrum efficiency increment of the 2nd CQI value, described accumulation CQI adjustment amount are cycle accumulative total spectrum efficiency increment for accumulating spectrum efficiency increment and described cycle accumulative total CQI adjustment amount.
The beneficial effect that the technical scheme that the embodiment of the invention provides is brought is:
By keeping the accumulation CQI adjustment amount in first moment, with first constantly corresponding accumulation CQI adjustment amount multiply by corresponding first confidence level and cycle totally the CQI adjustment amount add up, obtain corresponding accumulation CQI adjustment amount of second moment, according to the accumulation CQI adjustment amount in second moment the 2nd CQI information is revised then, CQI adjustment information before having taken full advantage of is adjusted current CQI, increase the sample size that CQI adjusts, improved the precision that CQI revises effectively.In addition, carry out the self adaptation adjustment according to accumulation BLER value to revising step-length, when the BLER value is very high or very low, suitably step-length is increased, can fast CQI be adjusted to suitable precision.
Embodiment
For making the purpose, technical solutions and advantages of the present invention clearer, embodiment of the present invention is described further in detail below in conjunction with accompanying drawing.
Embodiment 1
Referring to Fig. 1, present embodiment provides a kind of method of channel quality indication (CQI) information correction, comprising:
101: after first moment got access to a CQI information, calculate corresponding accumulation CQI adjustment amount of first moment;
102: after second moment got access to the 2nd CQI information, calculate first constantly and the cycle accumulative total CQI adjustment amount between second moment;
103: with first constantly corresponding accumulation CQI adjustment amount multiply by corresponding first confidence level and add up with cycle accumulative total CQI adjustment amount, obtain the second accumulation CQI adjustment amount of correspondence constantly;
104: with second constantly corresponding accumulation CQI adjustment amount multiply by corresponding second confidence level and the 2nd CQI information adds up, obtain revised the 2nd CQI information.
The method that present embodiment provides, by keeping the accumulation CQI adjustment amount in first moment, with first constantly corresponding accumulation CQI adjustment amount multiply by corresponding first confidence level and cycle totally the CQI adjustment amount add up, obtain corresponding accumulation CQI adjustment amount of second moment, according to the accumulation CQI adjustment amount in second moment the 2nd CQI information is revised then, CQI adjustment information before having taken full advantage of is adjusted current CQI, increase the sample size that CQI adjusts, improved the precision that CQI revises effectively.
The method of the channel quality indication (CQI) information correction that present embodiment provides is applicable to wireless communication system, LTE(Long Term Evolution especially, Long Term Evolution) system.Referring to Fig. 2, introduce in detail below in conjunction with instantiation.
At first, be defined as follows parameter:
I: in the moment of dispatching of the user uplink/downlink transfer of expression eNB, for convenience of description, present embodiment is with i ∈ (k
0, k
1] the CQI cycle be that example describes, the modification method of other cycles with this cycle is identical, does not repeat them here, wherein k
0Expression eNB gets access to the moment of a CQI information, and namely first constantly, k
1Expression eNB gets access to the moment of the 2nd CQI information, and namely second constantly, (k
0, k
1] CQI cycle of expression.
J: at i ∈ (k
0, k
1] the CQI cycle in j data block of transmission, i.e. data block j, wherein, for descending CQI, data block can be UE to the data block of eNB feeding back ACK/nack message, for up CQI, can be eNB judge whether the correct data block that receives by CRC check to data block.
V
Add(i): expression i is the CQI adjustment amount of correspondence constantly, and the CQI adjustment amount is CQI increment or spectrum efficiency increment, wherein, at wireless communication system, for example in the LTE system, CQI and spectrum efficiency have relation one to one, therefore, also can reach the purpose of adjusting CQI by adjusting spectrum efficiency.
V
Add-sum-period(i): expression i is the cycle accumulative total CQI adjustment amount in this corresponding CQI cycle constantly, and cycle accumulative total CQI adjustment amount is cycle accumulative total CQI increment or cycle accumulative total spectrum efficiency increment.
V
Add-sum: the accumulation CQI adjustment amount after each new CQI information is obtained, accumulation CQI adjustment amount is accumulation CQI increment or accumulation spectrum efficiency increment; For example, V
Add-sum(k
0) expression k
0The accumulation CQI adjustment amount that the moment is corresponding, V
Add-sum(k
1) expression k
1The accumulation CQI adjustment amount that the moment is corresponding.
MCS_eff
In(k
1): at k
1The 2nd CQI information that moment eNB obtains, first/the 2nd CQI information are CQI value or the corresponding spectrum efficiency of CQI value.
MCS_eff
Out(i): in i corresponding revised CQI output variable constantly, i.e. revised the 2nd CQI information, revised CQI output variable is revised CQI output valve or revised spectrum efficiency output valve.
K: the adjustment step-length ratio of the error message of this transmission and correct information; For downlink transfer, then K refers to the adjustment step-length ratio of NACK and ACK, specifically can be by the BLER(Block Error Rate of initial transmission, Block Error Rate) and the feedback error probability of NACK/ACK determine; For uplink, the adjustment step-length ratio when then K refers to that CRC check mistake and verification are correct specifically can be determined by initial BLER value.
Above-mentioned CQI is in the cycle, first k constantly
0Can be last CQI obtains CQI information in the cycle the moment, can be initial time also, the parameter that needs initialization CQI to revise:
Calculate and adjust parameter K, present embodiment does not limit concrete computational methods;
Arrange and adjust step-length step;
V parameter
Add(i)=0, V
Add-sum-period(i)=0, V
Add-sum(i)=0.
Based on above-mentioned definition and initialized parameter, concrete makeover process is as follows:
201: the base station basis (i-1, i] data block transmitted j calculates V in the time period
Add(i), can adopt following two kinds of methods to calculate at least:
First kind: whether correct according to data block transmitted, V is set
Add(i) be fixed value, concrete, if data block j transmission is correct, V
Add(i) be a preset positive value, for example, V
Add(i)=step, if data block j error of transmission, V
Add(i) be a preset negative value, for example, V
Add(i)=-K * step.
Second kind: according to this CQI in the cycle each period of the day from 11 p.m. to 1 a.m carve and correct and the accumulation Block Error Rate that this data block is corresponding whether of data block transmitted between its last period of the day from 11 p.m. to 1 a.m is carved, calculate CQI adjustment amount that each period of the day from 11 p.m. to 1 a.m is carved correspondence, referring to Fig. 2-1, specifically comprise:
201a: whether base station judgment data piece j is first transmission, if be first transmission, and execution in step 201b, otherwise, do not carry out any operation;
201b: correctly whether base station judgment data piece j transmission, if correct, carries out 201c, if erroneous transmissions is carried out 201d;
Concrete, if uplink, then whether the base station can correctly transmit by CRC check judgment data piece j, if the CRC check of this transmission data block is correct, represents that then this transmission is correct, if the CRC check mistake is then represented this error of transmission; If downlink transfer, whether the base station can correctly transmit according to the ACK/NACK information judgment data piece j of UE feedback, if receive ACK information, then data block j transmission is correct, if receive nack message, and then data block j error of transmission.
201c: the accumulation BLER when receiving data block j, calculate the value of adjusting upward V
Add(i);
Wherein, accumulation BLER value is the ratio of erroneous transmissions data block quantity and transmission of data blocks total quantity.
Concrete, when accumulation BLER value is between presetting first threshold x% and the second threshold value y%, V
Add(i) be a preset positive value, otherwise, V
Add(i) greater than this preset positive value.
For example, when x%≤BLER<y%, V
Add(i) adjust upward step-length, i.e. a V
Add(i)=step; When BLER<x%, V
Add(i) adjust upward 1.5 step-lengths, i.e. V
Add(i)=1.5 * step; When y%≤BLER, V
Add(i) adjust upward 2 step-lengths, i.e. V
Add(i)=2 * step.Further, y%≤BLER also can be identical with the adjustment step-length of BLER<x%.
201d: the accumulation BLER when receiving data block j, calculate downward adjusted value V
Add(i);
Wherein, accumulation BLER value calculating method is identical with 201c, repeats no more here.
Concrete, when accumulation BLER value is between presetting first threshold x% and the second threshold value y%, V
Add(i) be a preset negative value, otherwise, V
Add(i) less than this preset negative value.
For example, when x%≤BLER<y%, V
Add(i) adjust K step-length, i.e. V downwards
Add(i)=-K * step; When BLER<x%, V
Add(i) adjust 1.5 * K step-length, i.e. V downwards
Add(i)=-1.5 * K * step; When y%≤BLER, V
Add(i) adjust 2 * K step-length, i.e. V downwards
Add(i)=-2 * K * step.Further, y%≤BLER also can be identical with the adjustment step-length of BLER<x%.
Above-mentionedly carry out the self adaptation adjustment according to accumulation BLER value to revising step-length, when accumulation BLER value is very high or very low, suitably with the step-length increase, can fast CQI be adjusted to suitable precision.
202: the base station is according to V
Add(i) calculate MCS_eff
Out(i), referring to Fig. 2-2, specifically comprise:
202a: the base station is at moment i ∈ (k
0, k
1) do not get access to a new CQI, then upgrade the V in this CQI cycle
Add-sum-period(i) and MCS_eff
Out(i);
V
Add-sum-period(i)=V
Add-sum-period(i-1)+V
Add(i), V
Add-sum-period(i-1) cycle in this corresponding CQI cycle adds up the CQI adjustment amount to expression i-1 constantly.
MCS_eff
Out(i)=MCS_eff
Out(i-1)+V
Add(i), MCS_eff
Out(i) and MCS_eff
Out(i-1) represent the i moment and i-1 revised CQI output variable constantly respectively.
Further, can also limit V
Add-sum-periodAnd MCS_eff
OutScope.Present embodiment is established V
Add-sum-period∈ [a, b] also is V
Add-su-mperio dBe limited to a first time, be limited to b on first, if V
Add-su-mperio>
dB then makes V
Add-sum-periodIf=b is V
Add-sum-period<a then makes V
Add-sum-period=a.Adopt and V
Add-sum-periodIdentical restriction method can be with MCS_eff
OutBe limited in the default scope, for example MCS_eff
Out∈ [min{MCS_eff}, max{MCS_eff}], i.e. Yu She MCS_eff
OutBetween second lower limit and second upper limit.
202b: the base station is at moment i=k
1Get access to a new CQI, calculate V
Add-sum(k
1) and MCS_eff
Out(k
1);
V
Add-sum(k
1)=p (k
0) * V
Add-sum(k
0)+V
Add-sum-period(i=k
1), p (k
0) be k
0Confidence factor constantly, expression V
Add-sum(k
0) confidence level (first confidence level), p (k
0) ∈ [0,1]; V
Add-sum-period(i=k
1) can adopt the method for step 202a to calculate; Work as k
0During for initial time, V
Add-sum(k
0)=0, otherwise, V
Add-sum(k
0) can utilize this formula, the CQI information calculations that relevant information is replaced to its last cycle obtains.
Calculate V
Add-sum(k
1) afterwards, with V
Add-sum-periodZero clearing, i.e. V
Add-sum-period=0.
MCS_eff
Out(k
1)=MCS_eff
In(k
1)+
p(k
1) * V
Add-sum(k
1), p (k
1) be k
1Confidence factor constantly, expression V
Add-sum(k
1) confidence level (second confidence level), p (k
1) ∈ [0,1].In addition, the value of first confidence level and second confidence level can be the same or different.
Wherein, confidence factor belongs to [0,1], with UE(User Equipment, subscriber equipment) movement velocity relevant, the UE movement velocity is more big, confidence factor is more little, the UE movement velocity is more little, confidence factor is more big.The BLER influence of the different systems of CQI is inequality, for example: k
0CQI (k constantly
0) corresponding BLER=50%, k
1CQI (k constantly
1) corresponding BLER=20%, therefore can not be with CQI (k
0) corresponding adjusted value directly applies to CQI (k
1), adopt confidence factor to guarantee this cycle update information and the ratio of the confidence level of update information before here.
The method that present embodiment provides, by keeping the accumulation CQI adjustment amount in first moment, with first constantly corresponding accumulation CQI adjustment amount multiply by corresponding first confidence level and cycle totally the CQI adjustment amount add up, obtain corresponding accumulation CQI adjustment amount of second moment, according to the accumulation CQI adjustment amount in second moment the 2nd CQI information is revised then, CQI adjustment information before having taken full advantage of is adjusted current CQI, increase the sample size that CQI adjusts, improved the precision that CQI revises effectively.In addition, carry out the self adaptation adjustment according to accumulation BLER value to revising step-length, when the BLER value is very high or very low, suitably step-length is increased, can fast CQI be adjusted to suitable precision.
Embodiment 2
Referring to Fig. 3, present embodiment provides a kind of device of channel quality indication (CQI) information correction, comprising:
Accumulation module 301 is used for calculating corresponding accumulation CQI adjustment amount of first moment after first moment got access to a CQI information;
Computing module 302 is used for after second moment got access to the 2nd CQI information, calculates first constantly and the cycle accumulative total CQI adjustment amount between second moment;
Accumulator module 303, be used for accumulate module 301 obtains first constantly corresponding accumulation CQI adjustment amount multiply by corresponding first confidence level and add up with the cycle accumulative total CQI adjustment amount that computing module 302 obtains, obtain the accumulation CQI adjustment amount of second moment correspondence;
Correcting module 304, be used for accumulator module 303 obtain second constantly corresponding accumulation CQI adjustment amount multiply by the 2nd CQI information that corresponding second confidence level and computing module 302 obtain and add up, obtain revised the 2nd CQI information.
Further, computing module 302 comprises:
Computing unit, be used for according to first constantly and second each period of the day from 11 p.m. to 1 a.m between constantly carve carve with its last period of the day from 11 p.m. to 1 a.m between data block transmitted correct and accumulation Block Error Rate that data block is corresponding whether, calculate CQI adjustment amount that each period of the day from 11 p.m. to 1 a.m is carved correspondence;
The unit that adds up, each period of the day from 11 p.m. to 1 a.m that is used for computing unit is obtained is carved corresponding CQI adjustment amount and is added up, and obtains cycle accumulative total CQI adjustment amount.
Further, computing unit comprises:
First computing unit, be used for carving and its last period of the day from 11 p.m. to 1 a.m when data block transmitted is correct between quarter when each period of the day from 11 p.m. to 1 a.m, if the accumulation Block Error Rate of data block correspondence is between presetting first threshold and second threshold value time, it is a preset positive value that each period of the day from 11 p.m. to 1 a.m corresponding CQI adjustment amount at quarter is set, if the accumulation Block Error Rate of data block correspondence not between first threshold and second threshold value time, arranges each period of the day from 11 p.m. to 1 a.m and carves corresponding CQI adjustment amount greater than preset positive value;
Second computing unit, be used for carving and its last period of the day from 11 p.m. to 1 a.m between quarter during the data block transmitted mistake when each period of the day from 11 p.m. to 1 a.m, if the accumulation Block Error Rate of data block correspondence is between presetting first threshold and second threshold value time, it is a preset negative value that each period of the day from 11 p.m. to 1 a.m corresponding CQI adjustment amount at quarter is set, if the accumulation Block Error Rate of data block correspondence not between first threshold and second threshold value time, arranges each period of the day from 11 p.m. to 1 a.m and carves corresponding CQI adjustment amount less than preset negative value.
Further, computing module 302, if also be used for cycle accumulative total CQI adjustment amount greater than the first default upper limit, it is first upper limit that cycle accumulative total CQI adjustment amount is set;
If cycle accumulative total CQI adjustment amount is less than the first default lower limit, it is first lower limit that cycle accumulative total CQI adjustment amount is set.
Further, this device also comprises: dump block, and after being used for carrying out the function of accumulator module 303, will the zero clearing of cycle accumulative total CQI adjustment amount.
Wherein, a CQI information is that a CQI value, the 2nd CQI information are that the 2nd CQI value, accumulation CQI adjustment amount are cycle accumulative total CQI increment for accumulating CQI increment and cycle accumulative total CQI adjustment amount; Perhaps,
The one CQI information is that a CQI value corresponding spectrum efficiency increment, the 2nd CQI information are that the corresponding spectrum efficiency increment of the 2nd CQI value, accumulation CQI adjustment amount are cycle accumulative total spectrum efficiency increment for accumulating spectrum efficiency increment and cycle accumulative total CQI adjustment amount.
The device that present embodiment provides belongs to same design with base station among the method embodiment, and its specific implementation process sees method embodiment for details, repeats no more here.
The device that present embodiment provides, by keeping the accumulation CQI adjustment amount in first moment, with first constantly corresponding accumulation CQI adjustment amount multiply by corresponding first confidence level and cycle totally the CQI adjustment amount add up, obtain corresponding accumulation CQI adjustment amount of second moment, according to the accumulation CQI adjustment amount in second moment the 2nd CQI information is revised then, CQI adjustment information before having taken full advantage of is adjusted current CQI, increase the sample size that CQI adjusts, improved the precision that CQI revises effectively.In addition, carry out the self adaptation adjustment according to accumulation BLER value to revising step-length, when the BLER value is very high or very low, suitably step-length is increased, can fast CQI be adjusted to suitable precision.
All or part of content in the technical scheme that above embodiment provides can realize that its software program is stored in the storage medium that can read by software programming, storage medium for example: the hard disk in the computer, CD or floppy disk.
The above only is preferred embodiment of the present invention, and is in order to limit the present invention, within the spirit and principles in the present invention not all, any modification of doing, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.