CN104796247A - Resource allocation method for large-scale MIMO (multiple input multiple output) communication systems - Google Patents

Abstract

The invention discloses a resource allocation method for large-scale MIMO (multiple input multiple output) communication systems, belongs to the technical field of wireless communication and aims to solve the technical problem that pilot pollution causes mutual interference of multiple cells and multiple users by a simple and easy method. The resource allocation method includes: dividing resources into multiple parts, with the number of parts being equal to a maximal number of users in each cell; numbering the users in each cell and allocating the resources. The pilot sequences or data resources of the users, having the same numbers, in different cells are orthogonally intersected. The resource allocation method is suitable for the large-scale MIMO communication systems.

Description

A kind of resource allocation methods of extensive multiple-input-multiple-output communication system

Technical field

The present invention relates to wireless communication technology field, specifically, relate to a kind of resource allocation methods of extensive multiple-input-multiple-output communication system.

Background technology

Multi-antenna technology has been employed for some modern wireless systems, and this technology not only improves throughput but also can provide high-quality service for a large number of users.But along with increasing rapidly of number of users, wireless system small area internal interference has become the principal element that restriction transmission rate promotes, extensive multiple-input-multiple-output communication system (Multiple-Input Multiple-Output, be called for short MIMO) appearance can effectively alleviate this problem, the throughput of elevator system.

But in extensive multiple-input-multiple-output communication system, the interference problem of pilot pollution in other words between multiple cell multi-user, seriously restricts the lifting of this systematic function.Inventor finds, the method of existing anti-pilot pollution, mostly put forth effort on employing Anti-interference algorithm, carry out interference at receiving terminal to eliminate, and then obtain channel condition information (Channel State Information accurately, be called for short CSI), but the complexity of the reception mechanism of base station can be improved like this, that improves base station realizes cost.

Summary of the invention

The object of the present invention is to provide a kind of resource allocation methods of extensive multiple-input-multiple-output communication system, during to be existed by simple and easy to do method solution pilot pollution, between multiple cell multi-user, occur the technical problem of interference mutually.

The invention provides a kind of resource allocation methods of extensive multiple-input-multiple-output communication system, the method comprises:

Resource is divided into some parts, and the number of resource equals the maximum of each community user number;

For the Customs Assigned Number of each community and Resources allocation, wherein, pilot frequency sequence or the data resource of the user of the identical numbering in different districts are orthogonal and staggered.

Wherein, the pilot frequency sequence of the user of the identical numbering in different districts or data resource orthogonal and staggeredly to comprise:

The pilot frequency sequence of the user of the identical numbering in different districts is identical, and data resource is orthogonal and staggered in time domain.

Wherein, the pilot frequency sequence of the user of the identical numbering in different districts or data resource orthogonal and staggeredly to comprise:

The pilot frequency sequence of the user of the identical numbering in different districts is identical, and data resource is orthogonal and staggered on frequency domain.

Wherein, the pilot frequency sequence of the user of the identical numbering in different districts or data resource orthogonal and staggeredly to comprise:

The pilot frequency sequence of the user of the identical numbering in different districts is orthogonal and staggered, the time domain of data resource and frequency domain position overlap.

Wherein, some parts resource are divided into comprise:

Resource is average or non-be equally divided into some parts.

Wherein, the pilot frequency sequence of same user and data resource adopt time-multiplexed mode.

Wherein, in same community, the pilot frequency sequence of each user and data resource all adopt the mode of frequency division multiplexing.

Wherein, the frequency duplex factor as one of different districts is 1.

Present invention offers following beneficial effect: the resource allocation methods embodiments providing a kind of extensive multiple-input-multiple-output communication system, this method avoid targeted customer and be subject to a certain/certain user pilot pollution simultaneously and data interference, effectively raise the Signal to Interference plus Noise Ratio that receiving terminal receives data, improve the communication efficiency of user.

Other features and advantages of the present invention will be set forth in the following description, and, partly become apparent from specification, or understand by implementing the present invention.Object of the present invention and other advantages realize by structure specifically noted in specification, claims and accompanying drawing and obtain.

Accompanying drawing explanation

In order to be illustrated more clearly in the technical scheme in the embodiment of the present invention, accompanying drawing required in describing is done simple introduction below to embodiment:

Fig. 1 is the resource allocation methods flow chart of the extensive multiple-input-multiple-output communication system in the embodiment of the present invention;

Fig. 2 is the Resourse Distribute schematic diagram of single-carrier system up link of the prior art;

Fig. 3 is the Resourse Distribute schematic diagram of the single-carrier system up link in the embodiment of the present invention;

Fig. 4 is the Resourse Distribute schematic diagram of ofdm system up link of the prior art;

Fig. 5 is the Resourse Distribute schematic diagram of the ofdm system up link in the embodiment of the present invention.

Embodiment

Describe embodiments of the present invention in detail below with reference to drawings and Examples, to the present invention, how application technology means solve technical problem whereby, and the implementation procedure reaching technique effect can fully understand and implement according to this.It should be noted that, only otherwise form conflict, each embodiment in the present invention and each feature in each embodiment can be combined with each other, and the technical scheme formed is all within protection scope of the present invention.

Embodiments provide a kind of resource allocation methods of extensive multiple-input-multiple-output communication system, as shown in Figure 1, the method comprises:

Step S101, resource is divided into some parts, the number of resource equals the maximum of each community user number.

Extensive multiple-input-multiple-output communication system in the embodiment of the present invention, in order to flexible utilization resource, improves the utilance of resource, can adopt the mode of non-mean allocation; Accordingly, for the consideration reducing process complexity, this extensive multiple-input-multiple-output communication system also can adopt the mode of mean allocation.The resource allocation methods provided due to the embodiment of the present invention mainly considers the corresponding relation of data resource and pilot frequency sequence, therefore hereafter simple in order to describe, and only considers the mode of mean allocation resource.

If the number of users of each community is identical, then the number of resource is consistent with the number of users of each community.In addition, if the number of users of each community is not etc., then in order to ensure that the user of each community can carry out proper communication, the number of users of the community that the number of resource is maximum with number of users in each community is identical.

Step S102, for the Customs Assigned Number of each community and Resources allocation, wherein, pilot frequency sequence or the data resource of the user of the identical numbering in different districts are orthogonal and staggered.

For the resource allocation conditions of single-carrier system up link of the prior art, as shown in Figure 2, the pilot frequency sequence of the users such as the user 1 in community 1, user 2 and user 3 is orthogonal, the data resource of the pilot frequency sequence respective user 1 of user 1, accordingly, the data resource of the pilot frequency sequence respective user 2 of user 2, the data resource of the pilot frequency sequence respective user 3 of user 3.Further, be also same resource allocation conditions in community 2 and community 3.Meanwhile, the pilot frequency sequence of the user 1 that community 1, community 2 and community 3 are respective is identical, and accordingly, the pilot frequency sequence of the user 2 that community 1, community 2 and community 3 are respective is identical, and the pilot frequency sequence of the user 3 that community 1, community 2 and community 3 are respective is identical.

Namely the pilot frequency sequence of the user of same community difference numbering is orthogonal, the pilot frequency sequence of the user of the same numbering of different districts is identical, simultaneously, no matter overlapping mutually in time domain or frequency domain all customer data resource is, in this case, receiving terminal carries out least square method (Least Square, be called for short LS) channel estimating or linear minimum mean-squared error method (Linear Minimum Mean Square Error, be called for short LMMSE) channel estimating time, the pilot tone of the user of the same numbering in different districts can be disturbed mutually, cause pilot pollution, and then reduce the Signal to Interference plus Noise Ratio of receiving terminal, it is disturbed accurately to identify, differentiate the signal of each user.

Specifically, receiving terminal is after receiving the signal of user terminal, the operations such as pilot channel estimation, reception merging treatment (such as Maximal ratio combiner (Maximal Ratio Combining is called for short MRC) receives), input can be performed successively.If receiving terminal adopts extensive reception antenna, according to the processing procedure of the above-mentioned signal to user terminal, there is following formula:

${\mathrm{SIR}}_{\mathrm{jk}}=\frac{{\mathrm{\β}}_{\mathrm{jkj}}^2}{{\mathrm{\Σ}}_{l\≠j}{\mathrm{\β}}_{\mathrm{jkl}}^2}$

In above formula, SIR _jkfor the Signal to Interference plus Noise Ratio of j community receiving target user (k user); for energy slow fading (comprising free space to decline and the shadow fading) factor of channel between l community k user and j cell-site antenna.This formula illustrates, when receiving terminal adopts extensive antenna to carry out the reception of signal, reception accuracy restricts the user in the identical numbering in other communities completely, namely produces pilot pollution.

And in embodiments of the present invention, interfere with each other when communicating to prevent the user of the identical numbering in different districts, namely the situation that the reception accuracy brought of pilot pollution is limited occurs, can make the pilot frequency sequence of the user of the identical numbering in different districts or the orthogonal line interlacing of going forward side by side of data resource, wherein staggered concrete mode refers to hereafter.

In the first concrete enforcement scene that the embodiment of the present invention provides, the resource allocation conditions of single-carrier system up link is as shown in Figure 3 known, the pilot frequency sequence of the user 1 of community 1, user 2 and user 3 is orthogonal, but the data resource of the user 1 of community 1, user 2 and user 3 is orthogonal in time domain, not overlapping.Similar, in community 2 and community 3, the pilot frequency sequence of user 1, user 2 and user 3 is orthogonal, and data resource is orthogonal in time domain, not overlapping.

Further, in the concrete enforcement scene shown in Fig. 3, in community 1, community 2 and community 3, the data resource of the user of identical numbering is not only orthogonal in time domain, also staggered in time domain.Such as, for the user 1 of each community, receiving terminal at the data resource of the user 1 of the first reception community 1, at the data resource of the user 1 of the second reception community 2, at the data resource of the user 1 of the 3rd reception community 3.The data resource of the user of the identical numbering in different districts mutually staggers in time domain, the generation of the problem that the reception accuracy that can fundamentally prevent pilot pollution from bringing declines.

Wherein, in order to make the data resource of the user of the identical numbering in different districts orthogonal and staggered in sequential, when Resources allocation, can distribute according to the thought of cyclic shift.Such as, as shown in Figure 3, the data resource of the user 2 of community 1 is at the second reception, then according to the thought of cyclic shift, the data resource of the user 2 of community 2 is at the 3rd reception, and the data resource of the user 2 of community 3 is at the first reception.No matter there are how many communities, in each community, have how many users, all can carry out the distribution of resource according to the thought of cyclic shift.

In addition, also according to actual conditions, resource can be carried out Random assignment or other distribution methods.As long as can ensure that any user is subject to the source no user that the source user of pilot pollution and data disturb and occurs simultaneously, no matter which kind of distribution method is all applicable to the embodiment of the present invention.

Obviously, above-mentioned first specifically implements scene for single-carrier system, and for multicarrier system, the technical scheme that the embodiment of the present invention provides is applicable equally.Specific as follows:

As shown in Figure 4, for OFDM of the prior art (Orthogonal Frequency DiversityMultiplexing, be called for short OFDM) resource allocation conditions of system up-link, for community 1, community 2 and community 3, the frequency domain that the pilot frequency sequence of user 1, user 2 and user 3 is corresponding is spaced from each other, the pilot frequency sequence that user 1, user 2 and user 3 are respective simultaneously and data resource time domain are spaced from each other, and frequency domain is consistent.Deposit in case at pilot pollution, ofdm system cannot ensure the communication quality of user equally.

For ofdm system, specifically implement in scene in second of the embodiment of the present invention, as shown in Figure 5, in community 1, community 2 and community 3, pilot frequency sequence, the data resource of the user of different numbering are all spaced from each other on frequency domain, the data resource of the user of identical numbering time, overlapping on frequency domain, and the pilot frequency sequence of the user of identical numbering is orthogonal and staggered.Utilize staggered thought, the source user of the source user of pilot pollution and data interference can be made not occur simultaneously, such as, in the pilot frequency sequence of the user 1 of community 1, community 2, in the pilot frequency sequence of user 3 and community 3, the pilot frequency sequence of user 2 is identical, in the pilot frequency sequence of the user 2 of community 1, community 2, in the pilot frequency sequence of user 1 and community 3, the pilot frequency sequence of user 3 is identical, and in the pilot frequency sequence of the user 3 of community 1, community 2, in the pilot frequency sequence of user 2 and community 3, the pilot frequency sequence of user 1 is identical.Distribution like this, the generation of the problem that the reception accuracy that can fundamentally prevent pilot pollution from bringing declines.

Obviously, specifically implement in scene second, the same thought according to cyclic shift carries out the distribution of pilot frequency sequence.In addition, also according to actual conditions, resource can be carried out Random assignment or other distribution methods.As long as can ensure that the source user of pilot pollution and the source user of data interference do not occur simultaneously, no matter which kind of distribution method is all applicable to the embodiment of the present invention.

Second specifically implement scene about this, have following theoretical foundation:

Known F (F is the sub-carrier number of OFDM symbol) rank unit matrix is I _f=[e ₁, e ₂..., e _f], if $\mathrm{\Ω}=\{{\mathrm{\ω}}_1,{\mathrm{\ω}}_2,...,{\mathrm{\ω}}_n\}\⋐\{\mathrm{1,2},...,F\},$ Definition resource assignment matrix is $I_F^{\mathrm{\Ω}}=[e_{{\mathrm{\ω}}_1},e_{{\mathrm{\ω}}_2},...,e_{{\mathrm{\ω}}_n}].$

Known Fourier transform matrix is partial Fourier transform matrix is

Suppose that pilot frequency sequence and the data resource of the user k of community l can be expressed as:

And community l ₀the Received signal strength of base station end every root antenna m can be expressed as:

${\stackrel{\→}{r}}^{{\mathrm{cl}}_0\mathrm{am}}=\underset{l=1}{\overset{L}{\mathrm{\Σ}}}\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{H}_{\mathrm{am}}^{l_0\mathrm{cluk}}{\stackrel{\→}{x}}^{\mathrm{cluk}},$

Wherein,

Utilize resource assignment matrix defined above, obtain the reference signal of the user k received, as follows:

${\left(I_F^{{\mathrm{\Ω}}_k}\right)}^T{\stackrel{\→}{r}}_p^{{\mathrm{cl}}_0\mathrm{am}}={\left(I_F^{{\mathrm{\Ω}}_k}\right)}^T\underset{l=1}{\overset{L}{\mathrm{\Σ}}}\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\mathrm{diag}\left(h_{\mathrm{am},p}^{l_0\mathrm{cluk}}\right){\stackrel{\→}{x}}_p^{\mathrm{cluk}}=\underset{l=1}{\overset{L}{\mathrm{\Σ}}}\mathrm{diag}\left(h_{\mathrm{am},p_{{\mathrm{\Ω}}_k}}^{l_0{\mathrm{cluk}}_l^{{\mathrm{\Ω}}_k}}\right){\stackrel{\→}{x}}_{p_{{\mathrm{\Ω}}_k}}^{{\mathrm{cluk}}_l^{{\mathrm{\Ω}}_k}},$

In above formula second "=" according to can the character of reference resources allocation matrix, and to have

Community l ₀base station end to corresponding to Ω in this community _kthe user of upper Resources allocation channel estimating be:

${\hat{h}}_{\mathrm{am},p_{{\mathrm{\Ω}}_k}}^{l_0{\mathrm{cl}}_0{\mathrm{uk}}_{l_0}^{{\mathrm{\Ω}}_k}}={\left(I_F^{{\mathrm{\Ω}}_k}\right)}^T{\stackrel{\→}{r}}_p^{{\mathrm{cl}}_0\mathrm{am}}./{\stackrel{\→}{x}}_{p_{{\mathrm{\Ω}}_k}}^{{\mathrm{cluk}}_l^{{\mathrm{\Ω}}_k}}=\underset{l=1}{\overset{L}{\mathrm{\Σ}}}{h}_{\mathrm{am},p_{{\mathrm{\Ω}}_k}}^{l_0{\mathrm{cluk}}_l^{{\mathrm{\Ω}}_k}},$

Wherein, user be expressed as community l ₀in be assigned to Ω _kthe user of resource.

Above formula distortion can be obtained further:

${\hat{h}}_{\mathrm{am},p}^{l_0{\mathrm{cl}}_0{\mathrm{uk}}_{l_0}^{{\mathrm{\Ω}}_k}}=\underset{l=1}{\overset{L}{\mathrm{\Σ}}}{h}_{\mathrm{am},p}^{l_0{\mathrm{cluk}}_l^{{\mathrm{\Ω}}_k}}.$

Consider community l ₀the single Resource Unit of base station end multiple antennas on data:

In conjunction with channel estimating, after receiving terminal MRC detects, output is:

The interference that the interference pilot tone of certain user being subject to due to Resource Allocation Formula of the present invention, data are subject to comes from the interference user group of difference (without occuring simultaneously), be similar to mutually orthogonal character according to the different up channel of extensive antenna again, above formula can obtain sending signal accurately.

Above, embodiments provide a kind of resource allocation methods of extensive multiple-input-multiple-output communication system, this method avoid targeted customer and be subject to a certain/certain user pilot pollution simultaneously and data interference, effectively raise the Signal to Interference plus Noise Ratio that receiving terminal receives data, improve the communication efficiency of user.

Although execution mode disclosed in this invention is as above, the execution mode that described content just adopts for the ease of understanding the present invention, and be not used to limit the present invention.Technical staff in any the technical field of the invention; under the prerequisite not departing from spirit and scope disclosed in this invention; any amendment and change can be done what implement in form and in details; but scope of patent protection of the present invention, the scope that still must define with appending claims is as the criterion.

Claims (8)

1. a resource allocation methods for extensive multiple-input-multiple-output communication system, is characterized in that, comprising:

Resource is divided into some parts, and the number of resource equals the maximum of each community user number;

For the Customs Assigned Number of each community and Resources allocation, wherein, pilot frequency sequence or the data resource of the user of the identical numbering in different districts are orthogonal and staggered.

2. method according to claim 1, is characterized in that, the pilot frequency sequence of the user of the identical numbering in different districts or data resource orthogonal and staggeredly to comprise:

The pilot frequency sequence of the user of the identical numbering in different districts is identical, and data resource is orthogonal and staggered in time domain.

3. method according to claim 1, is characterized in that, the pilot frequency sequence of the user of the identical numbering in different districts or data resource orthogonal and staggeredly to comprise:

The pilot frequency sequence of the user of the identical numbering in different districts is identical, and data resource is orthogonal and staggered on frequency domain.

4. method according to claim 1, is characterized in that, the pilot frequency sequence of the user of the identical numbering in different districts or data resource orthogonal and staggeredly to comprise:

The pilot frequency sequence of the user of the identical numbering in different districts is orthogonal and staggered, the time domain of data resource and frequency domain position overlap.

5. the method according to any one of Claims 1-4, is characterized in that, resource is divided into some parts to comprise:

Resource is average or non-be equally divided into some parts.

6. method according to claim 5, is characterized in that,

The pilot frequency sequence of same user and data resource adopt time-multiplexed mode.

7. method according to claim 5, is characterized in that,

In same community, the pilot frequency sequence of each user and data resource all adopt the mode of frequency division multiplexing.

8. method according to claim 5, is characterized in that,

The frequency duplex factor as one of different districts is 1.