CN101720129B - Resource distribution method, base station and communication system - Google Patents

Abstract

The invention discloses a resource distribution method, a base station and a communication system. The method comprises the following steps of: calculating a first sub-carrier number used when meeting the first MCS demodulation threshold and a first throughput to be achieved under the first MCS by using the first sub-carrier number; calculating a second sub-carrier number used when meeting the second MCS demodulation threshold and a second throughput to be achieved under the second MCS by using the second sub-carrier number; comparing the first throughput with the second throughput, if the first throughput is greater than the second throughput, distributing sub-carriers with the number which is the first sub-carrier number corresponding to the first throughput for the MS and determining the first MCS corresponding to the first throughput as the MCS used by the MS. In the method, base station and system provided by the embodiment of the invention, the MCS with maximum throughput is selected as the MCS used by the MS, thereby improving the uplink throughput of the base station.

Description

Resource allocation methods, base station and communication system

Technical field

The present invention relates to the communication technology, relate in particular to a kind of resource allocation methods, base station and communication system.

Background technology

OFDM (Orthogonal Frequency Division Multiple Access; Be called for short OFDMA) with its availability of frequency spectrum and flexibility efficiently; By inserting of microwave whole world interoperability (the Wor1dwide Interoperability for Microwave Access Form of forum; Be called for short WiMAX) be adopted as aerial physical layer standard with Long Term Evolution project (Long Term Evolution, abbreviation LTE).The OFDMA system is as a multi-carrier communications systems, and is mutually orthogonal between each subcarrier, forms a plurality of low rate channels independent of each other, and a plurality of low rate channels merge, and can obtain an IA High Speed Channel.Under the certain situation of up path loss (being called for short " path loss "); The power that improves subcarrier just can obtain better upward signal; Satisfy higher modulation coding mode (Modulation Coding Scheme thus; Abbreviation MCS) demodulation threshold finally can transmit more upstream data on each subcarrier, obtain bigger up user throughput.

Similarly, under the certain situation of up path loss, the power of each subcarrier is fixedly the time, and the upstream data amount that each subcarrier can transmit is also relatively stable, uses more subcarriers, just can obtain high more up user's throughput.In order to obtain higher throughput, generally tend to distribute uplink sub-carrier as much as possible and the high as far as possible MCS of code rate to travelling carriage (MobileStation is called for short MS).Total transmitting power of MS increases along with the increase of number of subcarriers.When MS reached maximum generation power, the relation between sub-carrier power and the sub-carrier number was shown in formula (1):

Power _sc＝Tx _max-10*lg(SubcarrierNum) (1)

Wherein, Power _ScBe the corresponding sub-carrier power of the demodulation threshold of different MCS, Tx _MaxBe the maximum transmission power of MS, SubcarrierNum is a sub-carrier number.

In order to obtain big as far as possible uplink throughput, certain methods is provided in the prior art, yet the uplink throughput that these methods can obtain is limited.

Summary of the invention

The embodiment of the invention provides a kind of resource allocation methods, base station and communication system to the problem that prior art exists, and can improve the uplink throughput of base station.

The embodiment of the invention provides a kind of resource allocation methods, comprising: employable first sub-carrier number of institute and said first sub-carrier number of employing can reach under a said MCS first throughput when calculate satisfying the demodulation threshold of the first modulation coding mode MCS; Employable second carrier number of institute and said second sub-carrier number of employing can reach under said the 2nd MCS second throughput when calculate satisfying the demodulation threshold of the 2nd MCS; More said first throughput and second throughput; If comparative result is that said first throughput is greater than said second throughput; Be the subcarrier of the first corresponding sub-carrier number of said first throughput for the mobile station MS quantity allotted then, and confirm the MCS that the corresponding MCS of said first throughput uses as MS.

The embodiment of the invention also provides a kind of base station; Comprise: first processing module, employable first sub-carrier number of institute and said first sub-carrier number of employing can reach under a said MCS first throughput when being used to calculate the demodulation threshold that satisfies the first modulation coding mode MCS; Second processing module, employable second carrier number of institute and said second sub-carrier number of employing can reach under said the 2nd MCS second throughput when being used to calculate the demodulation threshold that satisfies the 2nd MCS; Comparison module is used for second throughput that first throughput that more said first processing module calculates and said second processing module calculate; Distribution module; The comparative result that is used at said comparison module is under the situation of said first throughput greater than said second throughput; For the mobile station MS quantity allotted is the subcarrier of the first corresponding sub-carrier number of said first throughput, and confirm the MCS that the corresponding MCS of said first throughput uses as MS.

The embodiment of the invention also provides a kind of communication system, comprise foregoing base station and with the MS of this base station communication.

The method that the embodiment of the invention provides, base station and communication system; Through first sub-carrier number under the demodulation threshold that calculates a MCS and first throughput; And second sub-carrier number under the demodulation threshold of the 2nd MCS and second throughput; With bigger in first throughput and second a throughput pairing sub-carrier number as the subcarrier data of distributing to MS, and with the MCS of bigger in first throughput and second a throughput pairing MCS as MS.Select MCS in this way, and the allocation of subcarriers number, can guarantee that the uplink throughput of base station is maximum, compared with prior art, improved the uplink throughput of base station.

Through accompanying drawing and embodiment, the technical scheme of the embodiment of the invention is done further detailed description below.

Description of drawings

Shown in Figure 1 is resource allocation methods embodiment flow chart of the present invention;

Shown in Figure 2 for the structural representation of base station embodiment one of the present invention;

Shown in Figure 3 for the structural representation of base station embodiment two of the present invention.

Embodiment

Be illustrated in figure 1 as resource allocation methods embodiment flow chart of the present invention, comprise:

Step 101, employable first sub-carrier number of institute and employing first sub-carrier number can reach under a MCS first throughput when calculate satisfying the demodulation threshold of a MCS.

Step 102, employable second carrier number of institute and said second sub-carrier number of employing can reach under the 2nd MCS second throughput when calculate satisfying the demodulation threshold of the 2nd MCS.

Step 103, comparison first throughput and second throughput; If comparative result is that first throughput is greater than second throughput; Be the subcarrier of the first corresponding sub-carrier number of first throughput for the MS quantity allotted then, and confirm the MCS that the corresponding MCS of first throughput uses as MS.

In the step 103, if comparative result be second throughput greater than first throughput, be the subcarrier of the second corresponding sub-carrier number of second throughput for the MS quantity allotted then, and confirm the MCS of the 2nd corresponding MCS of second throughput as the MS use.

If comparative result is that first throughput equals second throughput; At this moment first throughput is also identical with second sub-carrier number with first sub-carrier number of second throughput correspondence; Can be the subcarrier of the corresponding sub-carrier number of any throughput for the MS quantity allotted so, and confirm the MCS that the corresponding MCS of any throughput uses as MS.

Step 103 has come down to select a sub-carrier number and a MCS that bigger throughput is corresponding, so just can guarantee that current throughput is maximum.

In the step 101 and 102, when calculating first sub-carrier number and second sub-carrier number, can calculate according to the current sub-carrier power that MS reports.

The step of calculating first sub-carrier number in the step 101 can comprise:

101a, according to formula Power _Sc-1=Current Re portedPower _Sc+ (T arg etSNR ₁-sub-carrier power when CurrentSNR) calculate satisfying the demodulation threshold of a MCS: wherein, Power _Sc-1Be the corresponding sub-carrier power of demodulation threshold of a MCS, Current Re portedPower _ScBe the current sub-carrier power that said MS reports, T arg etSNR ₁Be the demodulation threshold of a MCS, CurrentSNR is the signal to noise ratio that current base station receives signal.

101b, according to formula ${\mathrm{SubcarrierNum}}_1={10}^{({\mathrm{Tx}}_{\mathrm{Max}}-{\mathrm{Power}}_{\mathrm{Sc}-1})/10}$ Employable first sub-carrier number when calculating the demodulation threshold that satisfies a MCS; Wherein, SubcarrierNum ₁Be first sub-carrier number, Power _Sc-1Be the corresponding sub-carrier power of demodulation threshold of a MCS, Tx _MaxMaximum transmission power for MS.

In the step 101, the step of calculating first throughput can comprise: according to formula ${\mathrm{Thruputput}}_1=M_1*{10}^{({\mathrm{Tx}}_{\mathrm{Max}}-{\mathrm{Power}}_{\mathrm{Sc}-1})/10}$ First throughput that calculating adopts first sub-carrier number to reach under a MCS; Wherein, Thruput ₁Be first throughput that a MCS adopts first sub-carrier number to reach down, M ₁It is the code check under the MCS demodulation threshold.

The step of calculating second sub-carrier number in the step 102 can comprise:

102a, according to formula Power _Sc-2=Current Re portedPower _Sc+ (T arg etSNR ₂-sub-carrier power when CurrentSNR) calculate satisfying the demodulation threshold of the 2nd MCS: wherein, Power _Sc-2Be the corresponding sub-carrier power of demodulation threshold of the 2nd MCS, Current Re portedPower _ScBe the current sub-carrier power that said MS reports, TargetSNR ₂Be the demodulation threshold of the 2nd MCS, CurrentSNR is the signal to noise ratio that current base station receives signal.

102b, according to formula ${\mathrm{SubcarrierNum}}_2={10}^{({\mathrm{Tx}}_{\mathrm{Max}}-{\mathrm{Power}}_{\mathrm{Sc}-2})/10}$ Employable second sub-carrier number when calculating the demodulation threshold that satisfies the 2nd MCS; Wherein, SubcarrierNum ₂Be second sub-carrier number, Power _Sc-2Be the corresponding sub-carrier power of demodulation threshold of the 2nd MCS, Tx _MaxMaximum transmission power for MS.

In the step 102, the step of calculating second throughput can comprise: according to formula ${\mathrm{Thruputput}}_2=M_2*{10}^{({\mathrm{Tx}}_{\mathrm{Max}}-{\mathrm{Power}}_{\mathrm{Sc}-2})/10}$ Second throughput that calculating adopts first sub-carrier number to reach under the 2nd MCS; Wherein, Thruput ₂Be second throughput that the 2nd MCS adopts second sub-carrier number to reach down, M ₂It is the code check under the 2nd MCS demodulation threshold.

In the foregoing description; Calculate a MCS corresponding sub-carrier power, first sub-carrier number and first throughput, and adopted respectively to the concrete formula of a MCS with to the concrete formula of the 2nd MCS when the corresponding sub-carrier power of the 2nd MSC, second sub-carrier number and second throughput.In practical application, the MCS kind is a lot, and the formula that calculates various MCS corresponding sub-carrier power, sub-carrier power and throughput can be summarized and is unified into following several formula:

The formula that calculates the corresponding sub-carrier power of different MCS demodulation thresholds can be shown in formula (2):

Power _sc＝Current?Re?portedPower _sc+(T?arg?etSNR-CurrentSNR) (2)

Wherein, Power _ScBe the corresponding sub-carrier power of different MCS demodulation thresholds, Current Re portedPower _ScBe the sub-carrier power that MS sends, T arg etSNR is the corresponding demodulation thresholds of different MCS, and demodulation threshold representes recently with noise that usually CurrentSNR is the signal to noise ratio (Signal Noise Ratio is called for short SNR) that current base station receives signal.

The formula that calculates corresponding sub-carrier number of different MCS demodulation threshold and throughput can be shown in formula (3) and (4):

$\mathrm{Thruputput}=M*{10}^{({\mathrm{Tx}}_{\max }-{\mathrm{Power}}_{\mathrm{sc}})/10}---\left(3\right)$

$\mathrm{SubcarrierNum}={10}^{({\mathrm{Tx}}_{\max }-{\mathrm{Power}}_{\mathrm{sc}})/10}---\left(4\right)$

In the formula (3), Thruput is a throughput, and M is the code check under the different MCS demodulation thresholds.

In the step 101 and 102, if first sub-carrier number that calculates greater than the upper limit of sub-carrier number, then with the upper limit of sub-carrier number as this first sub-carrier number; If second sub-carrier number that calculates is greater than the upper limit of sub-carrier number, then with the upper limit of sub-carrier number as this second sub-carrier number.

Below so that the implementation procedure of the embodiment of the invention one to be described based on the object lesson in the system of OFDMA.

Suppose that the MCS of use comprises 16QAM3/4,16QAM1/2, these three rank of QPSK1/2.QAM is quadrature amplitude modulation (Quadrature Amplitude Modulation is called for short QAM), and QPSK is the strong control of orthogonal phase shift (Quadrature Phase Shift Keying is called for short QPSK).The demodulation threshold of each rank MCS is shown in table one:

The demodulation threshold of table one, each rank MCS

MCS	Demodulation threshold
		16QAM3/4	15db
16QAM1/2	12db
		QPSK1/2	6db

Suppose that the maximum transmission power of MS is 23dbm, the up path loss of eating dishes without rice or wine increases so that the speed of 1db/s is linear.When sub-carrier power be-during 6dbm, MS reaches maximum transmission power, (that is to say that sub-carrier number reaches the upper limit, promptly sub-carrier number is 10 to the maximum to use whole uplink sub-carrier ^[23-(6)]/10).This moment, MCS was 16QAM3/4, and the signal to noise ratio that current base station receives signal is 15db.When sub-carrier power during less than-6dbm, MS does not reach maximum transmission power, and the sub-carrier number that calculates according to formula (3) equals the sub-carrier number upper limit.

In sub-carrier power be-during 6dbm; Up path loss continues to increase, and throughput descends, owing to reached the maximum transmission power of MS this moment; Obtain big as far as possible throughput so need or increase sub-carrier number, at this moment just need to select suitable MCS and sub-carrier number the MCS depression of order.

The base station receives the current sub-carrier power that MS reports, and based on aforementioned hypothesis, current sub-carrier power should be-6dbm, and the current base station snr of received signal is 15db.When path loss increases with the speed of 1db/s, be 15db if keep the base station received signal signal to noise ratio, then need guarantee that sub-carrier power promotes with the speed synchronization of 1db/s through reducing sub-carrier number.At this moment, sub-carrier number is 10 ^{[23-(6+x)]/10}, wherein, x is the path loss recruitment, the initial sub-carrier power of MS is-6dbm that if path loss increases x, then current sub-carrier power-6 adds x.Each base station all need calculate the sub-carrier power that various MCS need after receiving the sub-carrier power that MS reports.When path loss had increased 1.8db, the corresponding sub-carrier power of demodulation threshold that these three kinds of MCS of 16QAM3/4,16QAM1/2 and QPSK1/2 were calculated and obtained in the base station respectively was respectively:

P1＝Power _sc＝Current?Re?portedPower _sc+(T?arg?etSNR-CurrentSNR)

＝-6+1.8+(15-15)＝-4.2dbm

P2＝Power _sc＝Current?Re?portedPower _sc+(T?arg?etSNR-CurrentSNR)

＝-6+1.8+(12-15)＝-7.2dbm

P3＝Power _sc＝Current?Re?portedPower _sc+(T?arg?etSNR-CurrentSNR)

＝-6+1.8+(6-15)＝-13.2dbm

P1, P2, P3 are respectively the corresponding sub-carrier power of demodulation threshold of these three kinds of MCS of 16QAM3/4,16QAM1/2 and QPSK1/2, for 16QAM3/4, because path loss has increased 1.8db, so Current Re portedPower in the formula (2) _ScFor (6+1.8), CurrentSNR is 15db, can know according to table one, and T arg etSNR is 15db.For 16QAM1/2, because path loss has increased 1.8db, so Current Re portedPower in the formula (2) _ScFor (6+1.8), CurrentSNR is 15db, can know according to table one, and T arg etSNR is 12db.For QPSK1/24, because path loss has increased 1.8db, so Current Re portedPower in the formula (2) _ScFor (6+1.8), CurrentSNR is 15db, can know according to table one, and T arg etSNR is 6db.

When if MCS adopt to use 16QAM1/2 with QPSK1/2, this moment, it is maximum that the MS uplink transmission power does not also reach because the decline of demodulation threshold, so all calculate with-6dbm when calculating subcarrier, is maximum sub-carrier number.The sub-carrier power substitution formula (4) that the demodulation threshold of these three kinds of MCS is corresponding, the sub-carrier number that obtains three kinds of MCS correspondences is:

S1＝10 ^{[23-(-4.2)]/10}；

S2＝10 ^[23(-6)]/10；

S3＝10 ^[23-(-6)]/10。

S1, S2, S3 are respectively the corresponding sub-carrier number of demodulation threshold of these three kinds of MCS of 16QAM3/4,16QAM1/2 and QPSK1/2, Tx _MaxBe 23dbm, the sub-carrier power Power that the demodulation threshold of these three kinds of MCS of 16QAM3/4,16QAM1/2 and QPSK1/2 is corresponding _ScBe respectively-4.2dbm ,-7.2dbm and-13.2dbm.

When if MCS adopt to use 16QAM1/2 with QPSK1/2, this moment, it is maximum that the MS uplink transmission power does not also reach because the decline of demodulation threshold, so all calculate with-6dbm when calculating subcarrier, is maximum sub-carrier number.The sub-carrier power substitution formula (3) that the demodulation threshold of these three kinds of MCS is corresponding, the corresponding throughput of demodulation threshold that obtains three kinds of MCS is:

T1＝M1*10 ^{[23-(-4.2)]/10}＝3*10 ^{[23-(-4.2)]/10}；

T2＝M2*10 ^[23-(-6)]/10＝2*10 ^[23-(-6)1/10；

T3＝M3*10 ^[23-(-6)]/10＝10 ^[23-(-6)]/10。

M1, M2, M3 are respectively these three kinds of MCS corresponding code rate of 16QAM3/4,16QAM1/2 and QPSK1/2.T1, T2, T3 are respectively the corresponding throughput of demodulation threshold of these three kinds of MCS of 16QAM3/4,16QAM1/2 and QPSK1/2.

Compare T1, T2 and T3, T2 is maximum, and then the base station is with the MCS depression of order, and as current MCS, this MCS also is the MCS of the current use of MS with 16QAM1/2, and selects S2 as the sub-carrier number of distributing to MS.So-called depression of order is meant from the high MCS of code rate to become the low MCS of code rate.The modulating-coding speed of 16QAM3/4,16QAM1/2 is different; 3/4,1/2 presentation code efficient, the exponent number difference that different modulating-coding speed is corresponding is divided into MCS multistage usually; Exponent number is high more; Modulating-coding speed is high more, and for example, exponent number can be 16QAM3/4,16QAM1/2, QPSK1/2 respectively from high to low.

After the MCS that use 16QAM1/2 as current MS the base station, the base station adopts 16QAM1/2 to carry out the modulating-coding of signal, and the base station notifies the MCS of current employing to MS, makes MS also adopt 16QAM1/2 to carry out the modulating-coding of signal.The base station is also notified current sub-carrier number to MS.Like this, the base station uplink throughput just can reach maximum.

In the above-mentioned example; The base station calculates sub-carrier number and the throughput under the demodulation threshold of 16QAM3/4,16QAM1/2, these three kinds of MCS of QPSK1/2; Select the maximum MCS of throughput as current MCS; And distribute to the sub-carrier number of MS to the maximum corresponding sub-carrier number of MCS of this throughput the most, can guarantee uplink throughput maximum under current up path loss state of base station like this.

Above-mentioned example has provided three kinds of MCS, can use more kinds of MCS in the practical application, can certainly be two kinds of MCS.No matter but be two kinds of MSC or multiple MCS, all need compare between any two.So; When adopting the method that the embodiment of the invention provides; With regard to relation between the two; Can calculate first sub-carrier number and first throughput under the demodulation threshold of a MCS; And second sub-carrier number under the demodulation threshold of the 2nd MCS and second throughput, with bigger in first throughput and second a throughput pairing sub-carrier number as the subcarrier data of distributing to MS, and with the MCS of bigger in first throughput and second a throughput pairing MCS as MS.Select MCS in this way, and the allocation of subcarriers number, can guarantee that the throughput of single MS is maximum, thereby the uplink throughput that guarantees the base station is maximum, compared with prior art, has improved the uplink throughput of base station.

Through concrete data two kinds of effects that resource allocation methods is compared and can be obtained in uplink resource allocating method provided by the invention and the prior art are described below.

A kind of resource allocation methods that provides in the prior art is the efficiency comes first method; This method is specially: when MS reaches maximum transmission power; Satisfying under the service quality prerequisite of (Quality of Service is called for short QoS), preferentially use the higher MCS of code rate; When up path loss increases, improve the power of each subcarrier through continuous minimizing sub-carrier number, make the frequency efficiency of each subcarrier be fully used like this, thereby make that the uplink throughput of base station is maximum.

The another kind of resource allocation methods that provides in the prior art is a sub-carrier power efficiency comes first method, and this method is specially: when MS reaches maximum transmission power, satisfying under the prerequisite of QoS, preferentially use subcarrier as much as possible.Because the demodulation threshold of the MCS that exponent number is adjacent generally differs more than the 3db; If with the MCS depression of order; Operable number of subcarriers is 2 times before the depression of order; And the modulating-coding speed of the adjacent MCS of exponent number generally can not differ 2 times, so just can remedy because the loss of the code rate that depression of order brings.Keeping under the identical prerequisite of MS generation power, can obtain more effectively to utilize the transmitting power of MS than uplink throughput higher before the depression of order.

Still suppose that the MCS of use comprises 16QAM3/4,16QAM1/2, these three rank of QPSK1/2.The demodulation threshold of each rank MCS is shown in table one.Suppose that the maximum transmission power of MS is 23dbm, the up loss of eating dishes without rice or wine increases so that the speed of 1db/s is linear.When sub-carrier power be-during 6dbm, MS reaches maximum transmission power, uses whole uplink sub-carrier (that is to say that sub-carrier number reaches the upper limit).This moment, MCS was 16QAM3/4, and the signal to noise ratio that current base station receives signal is 15db.

Adopt the frequency efficiency mode of priority, MCS is 16QAM3/4 at the beginning.In sub-carrier power be-during 6dbm, sub-carrier number is 10 ^[23-(6)]/10, this sub-carrier number has reached the sub-carrier number upper limit.Up path loss continues to increase, and need guarantee frequency efficiency (promptly as far as possible guaranteeing to adopt high-order MCS) through reducing sub-carrier number.Along with sub-carrier number reduces, throughput is along curve 3*10 ^(23-x)/10Descend 3*10 ^(23-x)/10The corresponding throughput of sub-carrier power x during for 16QAM3/4.The minimum throughout of supposing qos requirement is 0.5*10 ^(23+6)/10, accounting equation 3*10 ^(23-x)/10=0.5*10 ^(23+6)/10, can get x=1.8dbm.That is to say that when throughput was reduced to the minimum throughout of qos requirement, sub-carrier power was 1.8dbm.Continuation increase along with up path loss; Sub-carrier power rises to the time that 1.8dbm needs [1.8-(6)]/1=7.8s from-6dbm; 7.8s afterwards, the sub-carrier power of 1.8dbm can't satisfy the demodulation threshold under the current MCS, then with the MCS depression of order to 16QAM1/2.The demodulation threshold of 16QAM1/2 is than the low 3db of the demodulation threshold of 16QAM3/4, and this moment, subcarrier transmitting power can corresponding reduction 3db, so sub-carrier power is reduced to 1.8-3=-1.2dbm from 1.8dbm.At this moment, throughput is 2*10 ^(23+12)/10Along with up path loss increases, guarantee frequency efficiency through reducing sub-carrier number, throughput is along curve 2*10 ^(23-x)/10Descend 2*10 ^(23-x)/10The corresponding throughput of sub-carrier power x during for 16QAM1/2.Accounting equation 2*10 ^(23-x)/10=0.5*10 ^(23+6)/10, can get x=0dbm.That is to say that when throughput was reduced to the minimum throughout of qos requirement, sub-carrier power was 0dbm.Continuation increase along with up path loss; Sub-carrier power rises to the time that 0dbm needs [0-(1.2)]/1=1.2s from-1.2dbm; 1.2s afterwards, the sub-carrier power of 0dbm can't satisfy the demodulation threshold under the current MCS, then with the MCS depression of order to QPSK1/2.The demodulation threshold of QPSK1/2 is than the low 6db of the demodulation threshold of 16QAM1/2, and this moment, subcarrier transmitting power can corresponding reduction 6db, so sub-carrier power is reduced to 0-6=-6dbm from 0dbm.At this moment, throughput is 10 ^(23+6)/10Along with up path loss increases, guarantee frequency efficiency through reducing sub-carrier number, throughput is along curve 10 ^(23-x)/10Descend 10 ^(23-x)/10The corresponding throughput of sub-carrier power x during for QPSK1/2.Accounting equation 10 ^(23-x)/10=0.5*10 ^(23+6)/10, can get x=-3dbm.That is to say that when throughput was reduced to the minimum throughout of qos requirement, sub-carrier power was-3dbm.Along with the continuation of up path loss increases, sub-carrier power from-6dbm rise to-3dbm needs the time of [3-(6)]/1=3s, this moment sub-carrier number 10 ^[23-(3)]/10With at the beginning 10 ^[23-(6)]/10Compare, reduced 1/2.

From MCS is 16QAM3/4 until QPSK1/2, and sub-carrier number is from 10 ^[23-(6)]/10Reduce to 10 ^[23-(3)]/10, up path loss has increased 12db, lasts 12s, and total throughput is:

$\underset{-6}{\overset{1.8}{\∫}}3*{10}^{(23-x)/10}\mathrm{dx}+\underset{-1.2}{\overset{0}{\∫}}2*{10}^{(23-x)/10}\mathrm{dx}+\underset{-6}{\overset{-3}{\∫}}{10}^{(23-x)/10}\mathrm{dx}=A.$

Adopt the subcarrier effect mode of priority, MCS is 16QAM3/4 at the beginning.In sub-carrier power be-during 6dbm, sub-carrier number is 10 ^[23-(6)]/10, this sub-carrier number has reached the sub-carrier number upper limit.Up path loss continues to increase, need be through the MCS depression of order being guaranteed sub-carrier number reaches the sub-carrier number upper limit.So to 16QAM1/2,16QAM1/2 compares with 16QAM3/4 with the MCS depression of order, demodulation threshold has reduced 3db, the corresponding reduction of sub-carrier power 3db, so sub-carrier power becomes-9dbm from-6dbm, throughput remains 2*10 ^(23+6)/10Along with the increase of up path loss, need sub-carrier power be risen to-6dbm from-9dbm, the SNR of up reception signal has reached the critical value of 16QAM1/2 demodulation threshold, that is to say, through behind [6-(9)]/1=3s, need be with the MCS depression of order to QPSK1/2.The MCS depression of order is behind QPSK1/2, and QPSK compares with 16QAM1/2, and demodulation threshold has reduced 6db, the corresponding reduction of sub-carrier power 6db, so sub-carrier power becomes-12dbm from-6dbm, throughput remains 10 ^(23+6)/10Along with up path loss increases, need sub-carrier power be risen to-6dbm from-12dbm, the SNR of up reception signal reaches the critical value of the demodulation threshold of QPSK1/2, that is to say, and through behind [6-(12)]/1=6s, sub-carrier power reaches-6dbm.Can't have to reduce the demodulation threshold that sub-carrier number satisfies QPSK1/2 this moment through the MCS depression of order being guaranteed sub-carrier number reaches the sub-carrier number upper limit.Through behind [3-(6)]/1=3s, sub-carrier power rises to-3dbm, and sub-carrier number is 10 ^(23+3)/10, with at the beginning 10 ^[23-(6)]/10Compare, reduced 1/2.

From MCS is 16QAM3/4 until QPSK1/2, and sub-carrier number is from 10 ^[23-(6)]/10Reduce to 10 ^[23-(3)]/10, up path loss has increased 12db, lasts 12s, and total throughput is:

$\underset{-9}{\overset{-6}{\∫}}2*{10}^{(23+6)/10}\mathrm{dx}+\underset{-12}{\overset{-6}{\∫}}{10}^{(23+6)/10}\mathrm{dx}+\underset{-6}{\overset{-3}{\∫}}{10}^{(23-x)/10}\mathrm{dx}=B.$

The method of the resource allocation that the employing embodiment of the invention provides, MCS is 16QAM3/4 at the beginning.In sub-carrier power be-during 6dbm, sub-carrier number is 10 ^[23-(6)]/10, this sub-carrier number has reached the sub-carrier number upper limit.Up path loss continues to increase, and throughput is along curve 3*10 ^(23-x)/10Descend; Speed decline 1.8s; Obtain the corresponding sub-carrier power of different MCS demodulation thresholds; The sub-carrier power that 16QAM3/4,16QAM1/2 and QPSK are corresponding is respectively-4.2dbm ,-7.2dbm ,-13.2dbm, then sub-carrier power separately is updated to formula (2) and (3), obtain throughput and be respectively: 3*10 ^(23+42)/10, 2*10 ^(23+6)/10, 10 ^(23+6)/10, the throughput that the demodulation threshold of 16QAM1/2 is corresponding is maximum, thus select the MCS depression of order to 16QAM1/2, and select 10 ^(23+6)/10As current sub-carrier number.Depression of order is behind 16QAM1/2, and demodulation threshold has reduced 3db, and correspondingly sub-carrier power reduces 3db, and sub-carrier power has the surplus of 1.2db, so behind the 1.2s, reach the maximum uplink transmission power of MS, throughput is along curve 2*10 then ^(23-x)/10Behind the decline 3s; The base station obtains the corresponding sub-carrier power of different MCS demodulation thresholds; The sub-carrier power that 16QAM3/4,16QAM1/2 and QPSK are corresponding be respectively 0dbm ,-3dbm with-(method of calculating sub-carrier power is with aforementioned identical for 9dbm; Repeat no more here), then sub-carrier power separately is updated to formula (2) and (3), obtain throughput and be respectively: 3*10 ^(23+0)/10, 2*10 ^(23+3)/10, 10 ^(23+6)/10, 10 ^(23+6)/10Maximum is so select the MCS depression of order to QPSK1/2.Behind QPSK1/2, demodulation threshold reduces 6db with the MCS depression of order, and sub-carrier power has the surplus of 3db, so, behind the 3s, reduce sub-carrier number again, to satisfy demodulation threshold.After passing through 3s again, sub-carrier power is increased to-3dbm from-6dbm, sub-carrier number and original 10 ^(23+6)/10Compare, reduced 1/2.

From MCS is 16QAM3/4 until QPSK1/2, and sub-carrier number is from 10 ^[23-(6)]/10Reduce to 10 ^[23-(3)]/10, up path loss has increased 12db, lasts 12s, and total throughput is:

$\underset{-6}{\overset{-4.2}{\∫}}3*{10}^{(23-x)/10}\mathrm{dx}+1.2*2*{10}^{(23+6)/10}+\underset{-6}{\overset{-3}{\∫}}2*{10}^{(23-x)/10}\mathrm{dx}+3*{10}^{(23+6)/10}+\underset{-6}{\overset{-3}{\∫}}{10}^{(23-x)/10}\mathrm{dx}=C.$

The resource allocation methods that adopts the embodiment of the invention to provide is compared with adopting the frequency efficiency mode of priority; Throughput in this 12s can increase (C-A)/A ≈ 18%; The resource allocation methods that adopts the embodiment of the invention to provide is compared with adopting the spectrum efficiency mode of priority, and the throughput in this 12s can increase (C-B)/B ≈ 15%.

Through above-mentioned comparison, can find out that the resource allocation methods that adopts the embodiment of the invention to provide can improve throughput.What be worth explanation is; In the above-mentioned example; The throughput of only having chosen in the 12s time compares, and the method that provides of the embodiment of the invention is not limited to the concrete time period in fact, in the whole base station and the communication process between the MS; The method that adopts the embodiment of the invention to provide can obtain big as far as possible uplink throughput.

Be illustrated in figure 2 as the structural representation of base station embodiment one of the present invention, this base station comprises first processing module 11, second processing module 12, comparison module 13 and distribution module 14.

Employable first sub-carrier number of institute and employing first sub-carrier number can reach under a MCS first throughput when first processing module 11 is used to calculate the demodulation threshold that satisfies a MCS.Employable second carrier number of institute and employing second sub-carrier number can reach under the 2nd MCS second throughput when second processing module 12 is used to calculate the demodulation threshold that satisfies the 2nd MCS.Comparison module 13 is used for second throughput that first throughput that comparison first processing module 11 calculates and second processing module calculate.The comparative result that distribution module 14 is used at comparison module 13 is under the situation of first throughput greater than second throughput; For the MS quantity allotted is the subcarrier of the first corresponding sub-carrier number of first throughput, and confirm the MCS that the corresponding MCS of first throughput uses as MS.

First processing module 11 specifically can be used for the current sub-carrier power that reports according to MS, employable first sub-carrier number of institute and said first sub-carrier number of employing can reach under a MCS first throughput when calculating the demodulation threshold that satisfies a MCS.

Second processing module 12 specifically can be used for the current sub-carrier power that reports according to MS, employable second sub-carrier number of institute and said second sub-carrier number of employing can reach under the 2nd MCS second throughput when calculating the demodulation threshold that satisfies the 2nd MCS.

Be illustrated in figure 3 as the structural representation of base station embodiment two of the present invention, in this base station, first processing module 11 can comprise first submodule 111 and second submodule 112.

First submodule 111 is used for according to formula Power _Sc-1=Current Re portedPower _Sc+ (T arg etSNR ₁-CurrentSNR), the sub-carrier power when calculating the demodulation threshold that satisfies a MCS; According to formula ${\mathrm{SubcarrierNum}}_1={10}^{({\mathrm{Tx}}_{\mathrm{Max}}-{\mathrm{Power}}_{\mathrm{Sc}-1})/10}$ Employable first sub-carrier number when calculating the demodulation threshold that satisfies a MCS.Second submodule 112 is used for according to formula ${\mathrm{Thruputput}}_1=M_1*{10}^{({\mathrm{Tx}}_{\mathrm{Max}}-{\mathrm{Power}}_{\mathrm{Sc}-1})/10},$ First throughput that calculating adopts first sub-carrier number to reach under a MCS.First sub-carrier number is that first submodule 111 calculates first sub-carrier number that obtains.

Second processing module 12 can comprise the 3rd submodule 121 and the 4th submodule 122.The 3rd submodule 121 is used for according to formula Power _Sc-2=Current Re portedPower _Sc+ (T arg etSNR ₂-sub-carrier power when CurrentSNR) calculate satisfying the demodulation threshold of the 2nd MCS: according to formula ${\mathrm{SubcarrierNum}}_2={10}^{({\mathrm{Tx}}_{\mathrm{Max}}-{\mathrm{Power}}_{\mathrm{Sc}-2})/10}$ Employable second sub-carrier number when calculating the demodulation threshold that satisfies the 2nd MCS.The 4th submodule 122 is used for according to formula ${\mathrm{Thruputput}}_2=M_2*{10}^{({\mathrm{Tx}}_{\mathrm{Max}}-{\mathrm{Power}}_{\mathrm{Sc}-2})/10}$ Second throughput that calculating adopts second sub-carrier number to reach under the 2nd MCS.Second sub-carrier number is that the 3rd submodule 121 calculates second sub-carrier number that obtains.

In Fig. 2 and embodiment shown in Figure 3, first processing module can also be used under the situation of first sub-carrier number greater than the sub-carrier number upper limit that calculates, with the upper limit of sub-carrier number as first sub-carrier number; Second processing module can also be used under the situation of second sub-carrier number greater than the sub-carrier number upper limit that calculates, with the upper limit of subcarrier as second sub-carrier number.

The embodiment of the invention also provides a kind of communication system, comprise as Fig. 2 or base station shown in Figure 3 and with the MS of this base station communication.Owing in apparatus embodiments, describe in detail, repeated no more in the base station in the system here about the base station.

When base station that the employing embodiment of the invention provides or system; Can calculate first sub-carrier number and first throughput under the demodulation threshold of a MCS; And second sub-carrier number under the demodulation threshold of the 2nd MCS and second throughput; With bigger in first throughput and second a throughput pairing sub-carrier number as the subcarrier data of distributing to MS, and with the MCS of bigger in first throughput and second a throughput pairing MCS as MS.Select MCS in this way, and the allocation of subcarriers number, can guarantee that the throughput of single MS is maximum, thereby the uplink throughput that guarantees the base station is maximum, compared with prior art, has improved the uplink throughput of base station.

Because the 4th generation, (4G) GSM generally adopted the interface-free resources Two dimensional Distribution based on OFDMA, therefore, the resource allocation methods that the embodiment of the invention provides also can be applied to the resource allocation of WiMAX system and LTE system.

One of ordinary skill in the art will appreciate that all or part of flow process that realizes in the foregoing description method; Be to instruct relevant hardware to accomplish through computer program; This program can be stored in the computer read/write memory medium; This program can comprise the flow process like the embodiment of above-mentioned each side method when carrying out.Wherein, this storage medium can be magnetic disc, CD, read-only storage memory body (Read-Only Memory is called for short ROM) or stores memory body (Random Acces s Memory is called for short RAM) etc. at random.

What should explain at last is: above embodiment is only in order to technical scheme of the present invention to be described but not limit it; Although the present invention has been carried out detailed explanation with reference to preferred embodiment; Those of ordinary skill in the art is to be understood that: it still can make amendment or be equal to replacement technical scheme of the present invention, also can not make amended technical scheme break away from the spirit and the scope of technical scheme of the present invention and these are revised or be equal to replacement.

Claims (5)

1. a resource allocation methods is characterized in that, comprising:

According to formula Power _Sc-1=Current ReportedPower _Sc+ (TargetSNR ₁-CurrentSNR), the sub-carrier power when calculating the demodulation threshold that satisfies a MCS;

Wherein, Power _Sc-1Be the corresponding sub-carrier power of demodulation threshold of a MCS, CurrentReportedPower _ScBe the current sub-carrier power that MS reports, TargetSNR ₁Be the demodulation threshold of a MCS, CurrentSNR is the signal to noise ratio that current base station receives signal;

According to formula

Employable first sub-carrier number when calculating the demodulation threshold that satisfies a MCS; Wherein, SubcarrierNum ₁Be first sub-carrier number, Power _Sc-1For calculate satisfy the demodulation threshold of a MCS time sub-carrier power, Tx _MaxMaximum transmission power for MS;

According to formula

First throughput that calculating adopts said first sub-carrier number to reach under a said MCS; Wherein, Thruput ₁Be first throughput that a MCS adopts said first sub-carrier number to reach down, M ₁It is the code check under the MCS demodulation threshold;

According to formula Power _Sc-2=CurrentReportedPower _Sc+ (TargetSNR ₂Sub-carrier power when one CurrentSNR) calculating the demodulation threshold that satisfies the 2nd MCS: wherein, Power _Sc-2Be the corresponding sub-carrier power of demodulation threshold of the 2nd MCS, CurrentReportedPower _ScBe the current sub-carrier power that said MS reports, TargetSNR ₂Be the demodulation threshold of the 2nd MCS, CurrentSNR is the signal to noise ratio that current base station receives signal;

According to formula

Employable second sub-carrier number when calculating the demodulation threshold that satisfies the 2nd MCS; Wherein, SubcarrierNum ₂Be second sub-carrier number, Power _Sc-2Be the corresponding sub-carrier power of demodulation threshold of the 2nd MCS, Tx _MaxMaximum transmission power for MS;

According to formula

Second throughput that calculating adopts first sub-carrier number to reach under the 2nd MCS; Wherein, Thruput ₂Be second throughput that the 2nd MCS adopts second sub-carrier number to reach down, M ₂It is the code check under the 2nd MCS demodulation threshold;

More said first throughput and second throughput; If comparative result is that said first throughput is greater than said second throughput; Be the subcarrier of the first corresponding sub-carrier number of said first throughput for the mobile station MS quantity allotted then, and confirm the MCS that the corresponding MCS of said first throughput uses as MS.

2. resource allocation methods according to claim 1 is characterized in that, if first sub-carrier number that calculates greater than the upper limit of sub-carrier number, then with the upper limit of sub-carrier number as this first sub-carrier number; If second sub-carrier number that calculates is greater than the upper limit of sub-carrier number, then with the upper limit of sub-carrier number as this second sub-carrier number.

3. a base station is characterized in that, comprising:

First processing module, said first processing module comprises:

First submodule is used for according to formula Power _Sc-1=CurrentReportedPower _Sc+ (TargetSNR ₁-CurrentSNR), the sub-carrier power when calculating the demodulation threshold that satisfies a MCS; Wherein, Power _Sc-1Be the corresponding sub-carrier power of demodulation threshold of a MCS, CurrentRe portedPower _ScBe the current sub-carrier power that said MS reports, TargetSNR ₁Be the demodulation threshold of a MCS, CurrentSNR is the signal to noise ratio that current base station receives signal; According to formula Employable first sub-carrier number when calculating the demodulation threshold that satisfies a MCS; Wherein, SubcarrierNum ₁Be first sub-carrier number, Power _Sc-1Be the corresponding sub-carrier power of demodulation threshold of a MCS, Tx _MaxMaximum transmission power for MS;

Second submodule is used for according to formula

First throughput that calculating adopts said first sub-carrier number to reach under a said MCS; Wherein, Thruput ₁Be first throughput that a MCS adopts said first sub-carrier number to reach down, M ₁It is the code check under the MCS demodulation threshold;

Second processing module is used for according to formula Power _Sc-2=Current Re portedPower _Sc+ (TargetSNR ₂-sub-carrier power when CurrentSNR) calculate satisfying the demodulation threshold of the 2nd MCS: wherein, Power _Sc-2Be the corresponding sub-carrier power of demodulation threshold of the 2nd MCS, CurrentReportedPower _ScBe the current sub-carrier power that said MS reports, TargetSNR ₂Be the demodulation threshold of the 2nd MCS, CurrentSNR is the signal to noise ratio that current base station receives signal; According to formula

Employable second sub-carrier number when calculating the demodulation threshold that satisfies the 2nd MCS; Wherein, SubcarrierNum ₂Be second sub-carrier number, Power _Sc-2Be the corresponding sub-carrier power of demodulation threshold of the 2nd MCS, Tx _MaxMaximum transmission power for MS; According to formula

Second throughput that calculating adopts first sub-carrier number to reach under the 2nd MCS; Wherein, Thruput ₂Be second throughput that the 2nd MCS adopts second sub-carrier number to reach down, M ₂It is the code check under the 2nd MCS demodulation threshold;

Comparison module is used for second throughput that first throughput that more said first processing module calculates and said second processing module calculate;

Distribution module; The comparative result that is used at said comparison module is under the situation of said first throughput greater than said second throughput; For the mobile station MS quantity allotted is the subcarrier of the first corresponding sub-carrier number of said first throughput, and confirm the MCS that the corresponding MCS of said first throughput uses as MS.

4. base station according to claim 3 is characterized in that, said first processing module also is used under the situation of first sub-carrier number greater than the sub-carrier number upper limit that calculates, with the upper limit of sub-carrier number as first sub-carrier number;

Said second processing module also is used under the situation of second sub-carrier number greater than the sub-carrier number upper limit that calculates, with the upper limit of subcarrier as second sub-carrier number.

5. a communication system is characterized in that, comprise as claim 3 or 4 described base stations and with the mobile station MS of said base station communication.

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