CN104980389A - Differential new user selection access method applicable to non-orthogonal multi-access system - Google Patents

Abstract

The invention provides a differential new user selection access method applicable to a non-orthogonal multi-access system, and relates to differential new user selection access technology applicable to non-orthogonal multi-access systems. The differential new user selection access method is used for enabling new users in the non-orthogonal multi-access system to better access the network. The method comprises the following steps: a first step, establishing an information resource pool of a full-band candidate user set; a second step, selecting sub-bands which satisfy bandwidth requirements; a third step, sequentially calculating differences of signal to interference plus noise power ratios; a fourth step, calculating a ratio A<l> of the number of users, satisfying preset standards, of each sub-band to the total number of candidate users of the sub-band, and sorting the ratios A<l> from small to large; a fifth step, carrying out selection according to the expression described in the specification; and a sixth step, carrying out non-orthogonal coding on the new access user information and other candidate user information through superposition coding, and conducting signal transmission. The differential new user selection access method provided by the invention is applicable to the differential new user selection access of the non-orthogonal multi-access system, and can satisfy the demand of a 5G new user access solution in the future.

Description

The new user's otherness being suitable for non-orthogonal multiple system selects cut-in method

Technical field

The present invention relates to a kind of new user's otherness being suitable for non-orthogonal multiple system (NOMA, Non-Orthogonal Multiple Access) and select access technology.

Background technology

Mobile communication technology develops into today, and frequency spectrum resource also becomes more and more nervous.Meanwhile, in order to meet the mobile service demand rapidly increased, people have started can meet in searching the new mobile communication technology that Consumer's Experience demand can improve again spectrum efficiency.There has been proposed non-orthogonal multiple technology (NOMA, Non-Orthogonal Multiple Access) under this background.

Non-orthogonal multiple technology (NOMA, Non-Orthogonal Multiple Access) basic thought be transmitting terminal adopt non-orthogonal manner send user profile, initiatively introduce interfere information, main employing superimposed code (SC, Superposition Coding) realize, correct demodulation is realized by serial interference delete (SIC, Successive Interference Cancellation) receiver or other effective receiver at receiving terminal.Although adopt the Receiver Complexity of SIC technology to improve, spectrum efficiency can be improved well.Spectrum efficiency is exchanged for, the essence of NOMA technology that Here it is by the complexity improving receiver.

The subchannel transmission of NOMA technology still adopts OFDM (OFDM, Orthogonal Frequency DivisionMultiplexing) technology, orthogonal between subchannel, do not interfere with each other, but every sub-channels no longer only distributes to a user, but multiple user shares.Same subchannel is non orthogonal transmissions between different user, will inter-user interference problem be produced like this, therefore, SIC technology will be adopted to carry out Multiuser Detection at receiving terminal, thus realize the correct object receiving corresponding information.At transmitting terminal, adopt power sharing technology to send to the different user on same subchannel, the signal power of different users is distributed according to relevant algorithm, and the signal power arriving each user of receiving terminal is like this different.SIC receiver carries out interference in a certain order according to different families signal power size again to be eliminated, and realizes correct demodulation, also reaches the object distinguishing user simultaneously.

New user's access scheme in LTE system is all for orthogonal multiple access system.New user's access scheme under non-orthogonal system cannot scheme under directly transplanting orthogonal system, needs new user's otherness of the applicable non-orthogonal multiple system of proposition one to select access scheme, meets the demand of the new user's access scheme of following 5G.

Summary of the invention

The present invention is better linked into network in order to the access customer that newly adds met under non-orthogonal multiple system, thus provides a kind of new user's otherness being suitable for non-orthogonal multiple system to select cut-in method.

The new user's otherness being suitable for non-orthogonal multiple system selects cut-in method, and it is realized by following steps:

Step one, whole frequency band B is divided into S sub-band, S is positive integer; The multiplexing N number of candidate user of each sub-band, N is positive integer; In each sub-band, the channel condition of self and affiliated sub-band number are placed in a memory by N number of candidate user, and sort by the size of sub-band; Thus set up the information resources pond of the candidate user collection of Whole frequency band;

Step 2, new access user are according to the business demand of self, the sub-band initial value meeting own service demand is selected in the information resources pond of the candidate user collection of Whole frequency band, record meets the sub-band sequence number of amount of bandwidth afterwards, and concentrates number of users to sort from small to large according to candidate user follow-up all sub-bands meeting bandwidth demand;

Step 3, sequence according to step 2, order computation is all to be met the dry of all candidate user in the sub-band of bandwidth demand and makes an uproar than difference, and judges whether to meet:

|SINR _i+1-SINR _j+1|>10dB

Record all candidate user numbers meeting this condition; J is positive integer, and the initial value of j is 0;

Step 4, calculate the ratio A that number of users that each sub-band meets step 3 conditional accounts for the total candidate user of this sub-band _l, and press ratio A _lsort from small to large;

Step 5, calculating:

$\underset{l\&Element;S}{\max }{A}_l$

The sub-band accessed is selected as new user;

Step 6, adopt supercomposed coding to realize nonopiate coding other candidate user information in new access user information and this sub-band, and carry out signal transmission.

According to the sequence of step 2 described in step 3, order computation is all to be met the dry of all candidate user in the sub-band of bandwidth demand and makes an uproar than difference, and judges whether to meet:

|SINR _i+1-SINR _j+1|>10dB

Recording all concrete grammars meeting the candidate user number of this condition is:

Step 3 one, by the user in sub-band i according to order from small to large arranges;

H _irepresent the gain of user i respective channels; σ _irepresent the noise power under user i respective channels;

Step 3 two, according to formula:

${\mathrm{\&Gamma;}}_j^i=\frac{{\mathrm{\&beta;}}_{i}P{\left|h_i\right|}^2}{P{\left|h_i\right|}^2{\mathrm{\&Sigma;}}_{k=i+1}^N{\mathrm{\&beta;}}_k+{\mathrm{\&sigma;}}_i^2}$

Calculate the Signal to Interference plus Noise Ratio of each candidate user i is sub-band order; The order of j user;

In formula: β _irepresent the power allocation factor of a jth user; The transmitting power that each sub-band of P distributes;

Step 3 three, according to formula:

${\mathrm{\&Delta;\&Gamma;}}_{i,j}^l=(\frac{{\mathrm{\&beta;}}_i{\left|h_i\right|}^2}{{\left|h_i\right|}^2{\mathrm{\&Sigma;}}_{k=i+1}^N{\mathrm{\&beta;}}_k+\frac{1}{P}{\mathrm{\&sigma;}}_i^2}-\frac{{\mathrm{\&beta;}}_j{\left|h_j\right|}^2}{{\left|h_j\right|}^2{\mathrm{\&Sigma;}}_{k=j+1}^N{\mathrm{\&beta;}}_k+\frac{1}{P}{\mathrm{\&sigma;}}_j^2})$

Calculate the difference of Signal to Interference plus Noise Ratio

Whether the difference that step 3 four, determining step three or three obtain meets:

|SINR _i+1-SINR _j+1|>10dB

Step 3 five, record meet the number of users of step 3 four.

Ratio A is pressed described in step 4 _lcarry out in the process sorted from small to large,

If there is the situation that ratio is equal, then the sub-band that prioritizing selection candidate user number is few; If there is the situation that ratio is all equal with candidate user number, then the sequencing between corresponding ratio is determined at random.

The one that the present invention proposes is suitable for the new user access method of non-orthogonal multiple system (NOMA, Non-Orthogonal Multiple Access), its main advantage: the new user access request one, meeting non-orthogonal system.Two, new access scheme has fully used for reference the advantage in orthogonal scheme, has both considered the overall channel maximum capacity of system, has considered again the fairness between user.The present invention can meet the demand of the new user's access scheme of following 5G.

Accompanying drawing explanation

Fig. 1 is the CDF curve emulation schematic diagram based on user SINR difference;

Fig. 2 is that under NOMA system, different sub-band user distributes emulation schematic diagram;

Fig. 3 is new user access method flow chart under NOMA system;

Fig. 4 is new user's access strategy performance simulation schematic diagram under NOMA system;

Embodiment

Embodiment one, composition graphs 1 to Fig. 4 illustrate this embodiment, and the new user access method under the non-orthogonal multiple system that this patent proposes, is mainly divided into following steps:

The first step: the information resources pond setting up Whole frequency band candidate user collection

Whole frequency band B is divided into S sub-band, the multiplexing N number of user of each sub-band, in order to new access user is linked into the sub-band meeting Applied criteria easily, first will set up the information resources pond of the candidate user collection of each sub-band on whole frequency band.

The information resources pond of candidate user of doing collection is that the channel condition of self and affiliated sub-band number are placed on a memory by the candidate user in each sub-band, sorts by the size of sub-band.The time of access has been saved in the foundation of resource pool.

Second step: chooser frequency band, meets bandwidth demand

New access user is according to the business demand of self, the sub-band initial value meeting self-demand is selected in resource pool, record meets the sub-band sequence number of amount of bandwidth afterwards, and follow-up all sub-bands meeting bandwidth demand are concentrated number of users order sequence from small to large according to candidate user.

3rd step: order computation Signal to Interference plus Noise Ratio difference (SINR Difference)

In order to ensure the error propagation (EP that user in sub-band selected in NOMA system is as far as possible little when receiving terminal adopts serial interference elimination (SIC), Error Propagation), need to select the difference of the Signal to Interference plus Noise Ratio between new user and candidate user to meet the curve shown in Fig. 1.

Curve from shown in Fig. 1:

|SINR _i+1-SINR _j+1|>10dB (3)

Meet (3) formula and just can ensure that less error propagation exists.

(1), by channel condition, user is sorted

By the user in sub-band i according to order arrangement from small to large.

(2) Signal to Interference plus Noise Ratio of user, is calculated

Wherein in i-th sub-band, the Signal to Interference plus Noise Ratio calculating formula of a jth user is:

${\mathrm{\&Gamma;}}_j^i=\frac{{\mathrm{\&beta;}}_{i}P{\left|h_i\right|}^2}{P{\left|h_i\right|}^2{\mathrm{\&Sigma;}}_{k=i+1}^N{\mathrm{\&beta;}}_k+{\mathrm{\&sigma;}}_i^2}---\left(4\right)$

Wherein represent the Signal to Interference plus Noise Ratio (SINR) of a jth user in i-th sub-band.

(3), SINR difference is calculated:

${\mathrm{\&Delta;\&Gamma;}}_{i,j}^l=(\frac{{\mathrm{\&beta;}}_i{\left|h_i\right|}^2}{{\left|h_i\right|}^2{\mathrm{\&Sigma;}}_{k=i+1}^N{\mathrm{\&beta;}}_k+\frac{1}{P}{\mathrm{\&sigma;}}_i^2}-\frac{{\mathrm{\&beta;}}_j{\left|h_j\right|}^2}{{\left|h_j\right|}^2{\mathrm{\&Sigma;}}_{k=j+1}^N{\mathrm{\&beta;}}_k+\frac{1}{P}{\mathrm{\&sigma;}}_j^2})---\left(5\right)$

(4) record meet the number of users of (3) formula.

4th step, calculate each sub-band and meet the ratio A that the number of users of (3) formula accounts for the total candidate user of each sub-band _l, by ratio A _lorder sequence from small to large.

5th step: select

Under the condition that ratio is equal, select the sub-band that candidate user number is few; If ratio is all equal with candidate user number, just select wherein at random.

6th step: adopt supercomposed coding to realize nonopiate coding new access user information and other candidate user information.The transmission of settling signal afterwards.

The present invention proposes the Applied criteria of algorithm:

1, power system capacity maximal criterion

$\underset{i\&Element;S}{\max }{C}_{\mathrm{NOMA}}\left(\mathrm{\&Gamma;}\right)---\left(1a\right)$

$s.t.\underset{j=1}{\overset{N}{\mathrm{\&Sigma;}}}{\mathrm{\&beta;}}_j=1,{\mathrm{\&beta;}}_j>0---\left(1b\right)$

$\underset{i=1}{\overset{S}{\mathrm{\&Sigma;}}}{W}_i=B,W_i>0---\left(1c\right)$

Wherein: C _nOMA(Γ) represent the channel capacity of NOMA multi-address system, Γ represents Signal to Interference plus Noise Ratio, and S represents the total number of sub-band that bandwidth B is distributed, β _jrepresent the power allocation factor of a jth user, N represents user's number multiplexing on each sub-band.

2, fairness criterion

Consider the fairness of each user's transmission rate,

$\underset{i\&Element;S}{\min }|R_{\mathrm{new}}-\frac{1}{N}{C}_{\mathrm{NOMA}}\left(\mathrm{\&Gamma;}\right)|---\left(2a\right)$

$s.t.\underset{j=1}{\overset{N}{\mathrm{\&Sigma;}}}{\mathrm{\&beta;}}_j=1,{\mathrm{\&beta;}}_j>0---\left(2b\right)$

$\underset{i=1}{\overset{S}{\mathrm{\&Sigma;}}}{W}_i=B,W_i>0---\left(2c\right)$

Wherein:

$R_i=\mathrm{lo}{g}_2(1+\frac{{\mathrm{\&beta;}}_{i}P{\left|h_i\right|}^2}{P{\left|h_i\right|}^2{\mathrm{\&Sigma;}}_{k=i+1}^N{\mathrm{\&beta;}}_k+{\mathrm{\&sigma;}}_i^2})$

Wherein: P represents the transmitting power that each sub-band distributes, | h _i| ²the gain of user i respective channels, represent the noise power under user i respective channels.

Below adopt concrete l-G simulation test that effect of the present invention is described:

1, application scenarios explanation

Due under non-orthogonal multiple system, the restriction of its channel condition of new access user, Resourse Distribute is the problem of a primary study, and interference be selected few, and SINR differs by more than on the sub-band of EP generation scope.Fig. 2 gives and accesses situation the user of different sub-bands.

2, new user access method flow chart under non-orthogonal multiple system

In order to describe said method clearly, provide the flow chart of method, as shown in Figure 3.

3, method performance simulation

According to the scheme that the present invention proposes, compare with traditional new user's random access scheme, its simulated effect figure as shown in Figure 4, wherein IWF (Iteration Water Filling), FTPA (Fractional Transmit Power Allocation) and FPA (FixedPower Allocation) power allocation scheme.

Under identical power allocation scheme, otherness of the present invention selects the performance of access to be obviously better than random selection scheme, and its performance makes an appointment 1.5dB greatly.

Claims (3)

1. the new user's otherness being suitable for non-orthogonal multiple system selects cut-in method, it is characterized in that: it is realized by following steps:

Step one, whole frequency band B is divided into S sub-band, S is positive integer; The multiplexing N number of candidate user of each sub-band, N is positive integer; In each sub-band, the channel condition of self and affiliated sub-band number are placed in a memory by N number of candidate user, and sort by the size of sub-band; Thus set up the information resources pond of the candidate user collection of Whole frequency band;

Step 2, new access user are according to the business demand of self, the sub-band initial value meeting own service demand is selected in the information resources pond of the candidate user collection of Whole frequency band, record meets the sub-band sequence number of amount of bandwidth afterwards, and concentrates number of users to sort from small to large according to candidate user follow-up all sub-bands meeting bandwidth demand;

Step 3, sequence according to step 2, order computation is all to be met the dry of all candidate user in the sub-band of bandwidth demand and makes an uproar than difference, and judges whether to meet:

|SINR _i+1-SINR _j+1|>10dB

Record all candidate user numbers meeting this condition; J is positive integer, and the initial value of j is 0;

Step 4, calculate the ratio A that number of users that each sub-band meets step 3 conditional accounts for the total candidate user of this sub-band _l, and press ratio A _lsort from small to large;

Step 5, calculating:

$\underset{l\&Element;S}{\max }{A}_l$

The sub-band accessed is selected as new user;

Step 6, adopt supercomposed coding to realize nonopiate coding other candidate user information in new access user information and this sub-band, and carry out signal transmission.

2. the new user's otherness being suitable for non-orthogonal multiple system according to claim 1 selects cut-in method, it is characterized in that the sequence according to step 2 described in step 3, order computation is all to be met the dry of all candidate user in the sub-band of bandwidth demand and makes an uproar than difference, and judges whether to meet:

|SINR _i+1-SINR _j+1|>10dB

Recording all concrete grammars meeting the candidate user number of this condition is:

Step 3 one, by the user in sub-band i according to order from small to large arranges;

H _irepresent the gain of user i respective channels; σ _irepresent the noise power under user i respective channels;

Step 3 two, according to formula:

${{\mathrm{\&Gamma;}}^i}_j=\frac{{\mathrm{\&beta;}}_{i}P{\left|h_i\right|}^2}{P{\left|h_i\right|}^2{\mathrm{\&Sigma;}}_{k=i+1}^N{\mathrm{\&beta;}}_k+{\mathrm{\&sigma;}}_i^2}$

Calculate the Signal to Interference plus Noise Ratio of each candidate user i is sub-band order; The order of j user;

In formula: β _irepresent the power allocation factor of a jth user; The transmitting power that each sub-band of P distributes;

Step 3 three, according to formula:

$\mathrm{\&Delta;}{\mathrm{\&Gamma;}}_{i,j}^l=(\frac{{\mathrm{\&beta;}}_i{\left|h_i\right|}^2}{{\left|h_i\right|}^2{\mathrm{\&Sigma;}}_{k=i+1}^N{\mathrm{\&beta;}}_k+\frac{1}{P}{\mathrm{\&sigma;}}_i^2}-\frac{{\mathrm{\&beta;}}_j{\left|h_j\right|}^2}{{\left|h_j\right|}^2{\mathrm{\&Sigma;}}_{k=j+1}^N{\mathrm{\&beta;}}_k+\frac{1}{P}{\mathrm{\&sigma;}}_j^2})$

Calculate the difference of Signal to Interference plus Noise Ratio

Whether the difference that step 3 four, determining step three or three obtain meets:

|SINR _i+1-SINR _j+1|>10dB

Step 3 five, record meet the number of users of step 3 four.

3. the new user's otherness being suitable for non-orthogonal multiple system according to claim 1 selects cut-in method, it is characterized in that described in step 4 by ratio A _lcarry out in the process sorted from small to large,

If there is the situation that ratio is equal, then the sub-band that prioritizing selection candidate user number is few; If there is the situation that ratio is all equal with candidate user number, then the sequencing between corresponding ratio is determined at random.