CN105790912B - The selection of ascending pilot frequency and distribution method in TDD mode m assive MIMO systems - Google Patents
The selection of ascending pilot frequency and distribution method in TDD mode m assive MIMO systems Download PDFInfo
- Publication number
- CN105790912B CN105790912B CN201410838686.1A CN201410838686A CN105790912B CN 105790912 B CN105790912 B CN 105790912B CN 201410838686 A CN201410838686 A CN 201410838686A CN 105790912 B CN105790912 B CN 105790912B
- Authority
- CN
- China
- Prior art keywords
- cell
- user
- pilot frequency
- pilot
- sequence
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Mobile Radio Communication Systems (AREA)
- Radio Transmission System (AREA)
Abstract
The present invention provides the selection of ascending pilot frequency and distribution method in a kind of tdd mode massive mimo systems, each cell interacts the associated pilot sequence use information of this cell to adjacent cell, and each cell base station interacts the uplink pilot sequence use information of user in cell and DTX patterns to adjacent each base station；Base station is according to interactive information, it determines in this cell using the dominant subspace using channel matrix between the user and the cell base station of identical uplink pilot sequence in the dominant subspace of channel matrix between the user and the cell base station of a certain uplink pilot sequence and its neighboring community；Judge whether the user in this cell can use identical uplink pilot sequence with the user in neighboring community by the relationship of two dominant subspaces of gained.The selection of ascending pilot frequency and distribution method reduce the ascending pilot frequency pollution of tdd mode massive mimo systems by the information exchange between user and base station and the information exchange between base station in the present invention.
Description
Technical field
The present invention relates to the ascending pilot frequency Pollution restraint sides in tdd mode multiple cell massive MIMO in a kind of 5G systems
Method, more particularly to a kind of TDD (Time Division Duplexing, time division duplex) mode m assive MIMO
The choosing of ascending pilot frequency in (massive Multiple Input Multiple Output, extensive multiple-input and multiple-output) system
It selects and distribution method.
Background technology
In the downlink of the massive mimo systems of tdd mode, in order to reduce the pilot-frequency expense of downlink, lead to
It is often used the method that pilot resources are multiplexed multiple wave beams, to introduce the ascending pilot frequency in multiple cell Massive mimo systems
Pollution.
As shown in Figure 1, having L cell in the extensive MU-MIMO system of tdd mode multiple cell.There are one N antennas for each cell
Base station (Base State, BS) and K single-antenna subscriber.Assuming that all L cells use identical K pilot frequency sequence, and
It is indicated with τ × K orthogonal dimension matrixes Φ, meets ΦHΦ=τ I.Further it is assumed that the pilot transmission of different community is synchronous.That
, the receipt signal matrix of base station iIt is represented by：
In formula, Hi,l∈CN×KChannel matrix is tieed up for N × K in cell l between K user and base station i,To lead
The noise matrix (wherein every is mean value 0, unit variance) to take place frequently during penetrating at the i of base station, ρpFor pilot transmission power.
In order to estimate that channel, base station i are received signal and project to Φ*On, to obtain for estimating channel Hi,iSystem
Metering.By formula (1) it is found that the channel matrix of estimation is：
In the derivation of above formula, Φ is utilizedHΦ=τ I.Kth rowFor channel vector hi,k,iEstimated value.
By formula (2) it is found thatTo use those of same pilot sequence subscriber channel vector h in different communityi,k,l(l=1 ..., L)
Linear combination.This phenomenon is known as pilot pollution.Since pilot pollution leads to channel estimation errors, not only so that uplink
Signal detection performance reduces, and if carrying out the precoding of downlink using the channel matrix, can be to undesired user
Cause prodigious interference.Therefore, Many researchers have carried out a large amount of research work to the method for reducing pilot pollution, it is proposed that
Some solutions.
At present, it has been proposed that some inhibit the scheme of pilot pollution.Several typical schemes are described below.
(1) the pilot pollution Restrain measurement based on agreement
Most directly a kind of method is led using the user of non-orthogonal pilot sequence to lower by channeling or reduction
Frequency polluting effect.But, it is however generally that, there is no can utilize massive MIMO energy concurrent multiplexing a large number of users for channeling
Advantage.This is because although this method improves the signal-to-noise ratio SINR of specific user, but the number of users serviced simultaneously reduces.
In the above-mentioned methods, all users send pilot frequency sequence simultaneously, this just will appear pilot pollution.In order to reduce pilot pollution,
The prior art proposes a kind of scheme being based on time shift (asynchronous) transport protocol, and basic thought is to divide the cell into several groups
A1,…,AΓ, and time shift transport protocol is used in each group, Fig. 2 is the example of Γ=3.As a group A1When middle user emits pilot tone,
Group A2In base station then send the data-signal of downlink.A group A is avoided in this way1With a group A2Pilot pollution between middle user.
At the same time, A is organized1Middle base station needs to exist from group A2With a group A3Estimation group A when the downlink transmitted signal of middle base station1
The channel matrix of middle user.Due to the transmission power ρ of downlinkdThe typically much deeper than power ρ of pilot frequency sequencep, therefore at present still
Do not know this method can provide how many gain.
(2) method based on precoding
Method for precoding based on multi-cell cooperating can inhibit pilot pollution effect.But the information needed between base station is handed over
Mutual expense increases with the increase of antenna number.Therefore, these methods are only applicable to the mimo system with finite antenna number.For
It obtains the advantage of cooperation and restricted information interacts expense, the prior art proposes a kind of pilot pollution precoding (PCP) scheme.
PCP schemes are based on two hypothesis：(a) each base station can obtain the source signal of all users in all cells；(b) all base stations can
Obtain large scale fading coefficient dI, k, l.Due to pilot pollution, channel estimation vectorTo use same pilot in different community
Those of sequence subscriber channel vector hi,k,lThe linear combination of (l=1 ..., L).In PCP schemes, each base station is not to inhibit
It is interfered caused by the channel estimation value that pollutes, but it is that all users send information in network to utilize pilot pollution.But have
Research shows that only working as antenna number N>106When, PCP schemes just begin with performance gain.
(3) it is based on the pilot pollution suppressing method of angle of arrival (AOA)
Some researches show that, in actual channel model, for identical or non-orthogonal pilot sequence certain user,
May and interference be not present between each other.According to the multipath channel models about even linear array (ULA), from cell l user k to
The channel matrix of base station i has following form：
In formula, Θ is multipath number,Independently of path sequence number θ,For the average path of user
Loss, a (θ) are the direction vector of array.For ULA, direction vector is represented by：
In formula, D is antenna spacing, and λ is the wavelength of carrier wave, and θ is the random arrival with probability density function (PDF) f (θ)
Angle (AOA).It is verified, though user use identical pilot frequency sequence, but as long as mutually with nonoverlapping AOA PDF, then its
Pilot tone is difficult to interfere with each other.According to the thought, prior art also teaches a kind of schemes reducing pilot pollution, i.e., will be identical
Pilot frequency sequence distributes to that class user mutually with the PDF for not being overlapped AOA.This method requires between each user of each base station
Correlation matrix meets its dominant subspace and is not overlapped this condition, and each base station is required to know that it is related between all users
Matrix.That is, if there is L base station, there is K user in each base station, then requires each base station that can obtain itself and LK user
Between LK correlation matrix.
Therefore, this method has following defect：
A, this method requires the correlation matrix between each user of each base station to meet its dominant subspace and is not overlapped this
Part, and each base station is required to know its correlation matrix between all users.That is, if there is L base station, in each base station
There is K user, then requires each base station that can obtain its LK correlation matrix between LK user.But actually base station is difficult to
Obtain the information of LK correlation matrix.
B, when 2 users have similar AOA to a certain base station in different community, then the two cannot be distinguished in the base station
User pollutes so as to cause ascending pilot frequency.
(4) the blind suppressing method of pilot pollution based on Subspace partition technology
Method based on Subspace partition technology can equally inhibit pilot pollution.In the prior art, it is proposed that based on spy
Value indicative decomposes the channel vector method of estimation of the channel estimation and iterative projection least square of (EVD).Feature based value is decomposed
(EVD) it is orthogonal that channel estimation methods, which require the channel vector of different user, which enables base station to utilize reception number
According to statistic estimate channel vector.In such methods multiplying property scalar fuzziness can utilize mutually orthogonal district pilots
Sequence solves.
This method may be summarized as follows：It is transmitted the stage in uplink, user elder generation transmission data signal, then sends cell and lead
Frequency sequence.
Estimation procedure includes the following steps：
Step 1：Estimation receives the covariance matrix of signal：
In formula,For the lth base station moment t reception signal.
Step 2：It solves N × K and ties up matrix Ul, kth is classified asCorresponding to close to characteristic value N ρudl,l,kCharacteristic Vectors
Amount.Moreover, by means of pilot frequency sequence, multiplying property matrix Ξ can getlEstimated value
Step 3：Calculate estimated value
But if using two users of same pilot sequence being all located at edge in adjacent two cell and at a distance of relatively close
When, two users are most likely in identical subspace, then EVD methods are difficult to separate the subspace of two users.At this point,
Blind method based on EVD will be unable to effectively reduce pilot pollution.
Invention content
In view of the foregoing deficiencies of prior art, the purpose of the present invention is to provide a kind of tdd mode massive
The selection of ascending pilot frequency and distribution method in mimo system are handed over by the information exchange between user and base station and the information between base station
Mutually, the ascending pilot frequency pollution in tdd mode massive mimo systems is significantly reduced.
In order to achieve the above objects and other related objects, in a kind of tdd mode massive mimo systems of present invention offer
The selection of ascending pilot frequency and distribution method, it is assumed that the massive mimo systems of tdd mode have L cell, each base station to have M roots day
Line, be up to K uplink pilot sequence pilot frequency sequence ak, k=1,2 ..., K have K user in each cell；Each base station is by K items
Uplink pilot sequence akK user in cell is distributed to, user k uses pilot frequency sequence ak；The selection of ascending pilot frequency and distribution side
Method includes the following steps：
Step S1：Assuming that using pilot frequency sequence a in cell lkUser k DTX patterns be pl,k, cell l is by this cell
Associated pilot use information is with the format { ID of cell l：(user's k uplink pilot sequences akSerial number, the DTX patterns of user k
pl,k, k=1,2 ..., K) } interaction give its adjacent (L-1) a cell；
Step S2：When the base station of cell l receives associated pilot use information { the cell j from adjacent (L-1) a cell
ID：(user's k uplink pilot sequences akSerial number, the DTX patterns p of user kj,k, k=1,2 ..., K), j=1 ..., l-1, l+
1 ..., L } after, according in this cell and neighboring community use pilot frequency sequence akUser DTX patterns, calculate adjacent (L-1) it is a
Pilot frequency sequence a is used in cellkUser send signal during union, obtain in adjacent (L-1) a cell use pilot tone
Sequence akTotal DTX patterns, and calculate total DTX patternsSupplementary set
Assuming that the base station of cell l receives T in the total inspection timepA reception sample of signal, whereinTransmission signal
There is T in periodaA reception sample of signal, andTransmission signal during in have Tb=(Tp-Ta) a reception sample of signal；
According to TaAnd TbRelationship determine in this cell use pilot frequency sequence akUser k whether can be a small with adjacent (L-1)
Pilot frequency sequence a is used in areakUser use identical uplink pilot sequence ak。
According to the selection of ascending pilot frequency and distribution method in above-mentioned tdd mode massive mimo systems, wherein：It is described
In step S2, the uplink received signal of the base station of cell lFor
Wherein, ρpIndicate the transmission power of ascending pilot frequency, Hl,jIt indicates to use pilot frequency sequence a in cell jkUser and cell
Channel matrix between the base station of l,For additive white Gaussian noise.
According to the selection of ascending pilot frequency and distribution method in above-mentioned tdd mode massive mimo systems, wherein：If
TbLength can calculate in cell l use pilot frequency sequence akUser uplink base station at receive signal space correlation
Matrix, then the base station of cell l calculate separatelyTransmission signal during andSend signal during it is middle receive signal sky
Between correlation matrix；
Transmission signal during, base station receive only user in its adjacent (L-1) a cell transmission pilot tone letter
Number, it receives signal and is expressed as
Send signal during spatial correlation matrix it is as follows：
Eigenvalues Decomposition beTo obtain the feature matrix corresponding to dominant eigenvalue
Transmission signal during, base station receives only the pilot signal that user k in its this cell is sent, that is, receives
Signal is expressed as
Send signal during spatial correlation matrix it is as follows：
Eigenvalues Decomposition beTo obtain the feature matrix corresponding to dominant eigenvalue
The base station of cell l according toWithRelationship, determine in cell l user k can with pilot tone is used in neighboring community
Sequence akUser use identical pilot frequency sequence ak。
Further, according to the selection of ascending pilot frequency and distribution method in above-mentioned tdd mode massive mimo systems,
Wherein：The base station of cell l according toWithRelationship, determine in cell l user k can with pilot tone sequence is used in neighboring community
Arrange akUser use identical pilot frequency sequence akWhen,
IfCell l uses pilot frequency sequence akUser cannot in neighboring community use pilot tone sequence
Arrange akUser use identical uplink pilot sequence ak；
IfCell l uses pilot frequency sequence akUser k can in neighboring community use pilot frequency sequence
akUser use identical uplink pilot sequence ak。
According to the selection of ascending pilot frequency and distribution method in above-mentioned tdd mode massive mimo systems, wherein：If
Pilot tone a is used in adjacent (L-1) a cell of cell lkThe user of sequence is without using DTX transmission modes, then cell l at this time
Base station be this cell in use pilot tone akThe user k of sequence configures a short-term DTX transmission modes pl,k, and notify the use
Family enters DTX transmission modes pl,k；After receiving the configuration information, which enters DTX transmission modes pl,k；
Base station calculates separately p in cell ll,kTransmission signal during p 'l,kNot p during pilot signal transmitted "l,kIn connect
The spatial correlation matrix of the collection of letters number, and determine use pilot frequency sequence a in neighboring community and this cell respectivelykMobile subscriber master
The feature matrix of characteristic value；
It is determined in this cell in user k and neighboring community according to the relationship between the feature matrix of two dominant eigenvalues
User k whether can use identical pilot frequency sequence ak。
Further, according to the selection of ascending pilot frequency and distribution method in above-mentioned tdd mode massive mimo systems,
Wherein：It is determined in this cell in user k and neighboring community according to the relationship between the feature matrix of two dominant eigenvalues
Whether user k can use identical pilot frequency sequence akWhen,
The transmission pilot frequency sequence a of user k in cell lkPeriod p 'l,k, serving BS simultaneously receive the user transmission
Pilot frequency sequence akThe pilot frequency sequence a sent with adjacent cell userk, receive signal and be expressed as：
pkSend signal during correlation matrix it is as follows：
Eigenvalues Decomposition beAnd obtain the feature matrix corresponding to its dominant eigenvalue
User k's does not send pilot frequency sequence a in cell lkPeriod p "l,k, serving BS receives only its adjacent (L-1)
The pilot frequency sequence a that community user is sentk；Signal is received to be expressed as：
Receive signal correlation matrix be：
Eigenvalues Decomposition beAnd obtain the feature matrix corresponding to its dominant eigenvalue
The base station of cell l according toWithDimension relation, determine user k and adjacent (L-1) a cell in its this cell
In user k whether can use identical pilot frequency sequence ak。
Further, according to the selection of ascending pilot frequency in above-mentioned tdd mode massive mimo systems and distribution side
Method, wherein：The base station of cell l according toWithDimension relation, determine user k and adjacent (L-1) a cell in its this cell
In user k whether can use identical pilot frequency sequence akWhen,
IfDimension withDimension it is identical, cell l use pilot frequency sequence akUser cannot in neighboring community
Use pilot frequency sequence akUser use identical uplink pilot sequence ak；
IfDimension be more thanDimension, cell l use pilot frequency sequence akUser can be used with neighboring community
Pilot frequency sequence akUser use identical uplink pilot sequence ak。
As described above, the selection of ascending pilot frequency and distribution method in the tdd mode massive mimo systems of the present invention, tool
There is following advantageous effect：
(1) by the information exchange between user and base station and the information exchange between base station, tdd mode is significantly reduced
Ascending pilot frequency pollution in massive mimo systems；
(2) these information exchanges are likely to be standardized in following massive mimo systems.
Description of the drawings
Fig. 1 is shown as the schematic diagram of the extensive MU-MIMO system of cell in the prior art；
Fig. 2 is shown as the schematic diagram of the pilot schemes based on time shift in the prior art；
Fig. 3 is shown as the selection of ascending pilot frequency and distribution method in the tdd mode massive-MIMO systems of the present invention
Flow chart.
Specific implementation mode
Illustrate that embodiments of the present invention, those skilled in the art can be by this specification below by way of specific specific example
Disclosed content understands other advantages and effect of the present invention easily.The present invention can also pass through in addition different specific realities
The mode of applying is embodied or practiced, the various details in this specification can also be based on different viewpoints with application, without departing from
Various modifications or alterations are carried out under the spirit of the present invention.
It should be noted that the diagram provided in the present embodiment only illustrates the basic conception of the present invention in a schematic way,
Then component count, shape and size when only display is with related component in the present invention rather than according to actual implementation in schema are painted
System, when actual implementation kenel, quantity and the ratio of each component can be a kind of random change, and its assembly layout kenel also may be used
It can be increasingly complex.
It is first, each small in the tdd mode massive-MIMO systems of the present invention in the selection and distribution method of ascending pilot frequency
Area interacts the associated pilot sequence use information of this cell to neighboring community, and each cell base station leads the uplink of user in cell
Frequency sequence use information and DTX patterns are interacted to adjacent each base station；Then, base station is led according to the correlation from neighbor cell base station
The interactive information of frequency sequence use information determines in this cell using between the user and the cell base station of a certain uplink pilot sequence
Believe using between the user and the cell base station of identical uplink pilot sequence in the dominant subspace of channel matrix and its neighboring community
The dominant subspace of road matrix；Finally, whether can come the user judged in this cell by the relationship of two dominant subspaces of gained
Identical uplink pilot sequence is used with the user in neighboring community.
Assuming that the massive mimo systems of tdd mode have L cell, each base station to have M root antennas.Further it is assumed that at most
There is K uplink pilot sequence pilot frequency sequence ak(k=1,2 ..., K), and have K user in each cell.Moreover, it is assumed that each base station
By K uplink pilot sequence akK user in cell is distributed to, and assumes that user k uses pilot frequency sequence ak。
With reference to Fig. 3, in tdd mode massive-MIMO systems of the invention the selection of ascending pilot frequency include with distribution method
Following steps：
Step S1：Assuming that using pilot frequency sequence a in cell lkUser k DTX (user discontinuously propagates) pattern be pl,k,
Cell l is by the associated pilot use information of this cell with the format { ID of cell l：(user's k uplink pilot sequences akSerial number, use
The DTX patterns p of family kl,k, k=1,2 ..., K) } interaction give its adjacent (L-1) a cell.
Step S2：When the base station of cell l receives associated pilot use information { the cell j from adjacent (L-1) a cell
ID：(user's k uplink pilot sequences akSerial number, the DTX patterns p of user kj,k, k=1,2 ..., K), j=1 ..., l-1, l+
1 ..., L } after, according in this cell and neighboring community use pilot frequency sequence akUser DTX patterns, calculate adjacent (L-1) it is a
Pilot frequency sequence a is used in cellkUser send signal during union, obtain in adjacent (L-1) a cell use pilot tone
Sequence akTotal DTX patterns, and calculate total DTX patternsSupplementary set
Assuming that the base station of cell l receives T in the total inspection timepA reception sample of signal, whereinTransmission signal
There is T in periodaA reception sample of signal, andTransmission signal during in have Tb=(Tp-Ta) a reception sample of signal.Cell
The uplink received signal of the base station of lWith following form:
In formula, ρpIndicate the transmission power of ascending pilot frequency, Hl,jIt indicates to use pilot frequency sequence a in cell jkUser and cell
Channel matrix between the base station of l,For additive white Gaussian noise.
According to TaAnd TbRelationship, the base station of cell l divides the following two kinds situation (when for other situations, using similar place
Reason method) come determine in this cell use pilot frequency sequence akUser k whether can in adjacent (L-1) a cell use pilot tone sequence
Arrange akUser use identical uplink pilot sequence ak：
A, situation 1：
If TbLength be enough to calculate in cell l use pilot frequency sequence akUser uplink base station at receive letter
Number spatial correlation matrix, then the base station of cell l calculate separatelyTransmission signal during andTransmission signal during in
Receive the spatial correlation matrix of signal.
BecauseTransmission signal during, base station receives only the transmission pilot tone of user in its adjacent (L-1) a cell
Signal receives signal and is represented by
It calculates Send signal during spatial correlation matrix it is as follows：
Then, it calculatesEigenvalues DecompositionAnd thus obtain the spy for corresponding to its dominant eigenvalue
Levy vector matrix
On the other hand, existTransmission signal during, base station receives only the pilot tone letter that user k in its this cell is sent
Number, i.e., it receives signal and is represented by
Then, it calculates Send signal during spatial correlation matrix it is as follows：
Then, it calculatesEigenvalues DecompositionAnd thus obtain the spy for corresponding to its dominant eigenvalue
Levy vector matrix
Finally, the base station of cell l according toWithRelationship, determine that can user k make with neighboring community in cell l
With pilot frequency sequence akThose of user use identical pilot frequency sequence ak.It is specific as follows：
If a)Show to use pilot frequency sequence a in cell lkUser k and the base stations cell l between channel
Pilot frequency sequence a is used in matrix and adjacent (L-1) a cellkThose of have between channel matrix between user and the base stations cell l
There is very strong correlation.At this point, cell l uses pilot frequency sequence akUser and the ascending pilot frequency of its adjacent cell user between exist it is strong
Interference.So cell l uses pilot frequency sequence akUser cannot use ak, need to distribute other ascending pilot frequency sequences for the user
Row；
If b)Then cell l uses pilot frequency sequence akUser k and the uplink of its adjacent cell user lead
Strong jamming is not present between frequency.At this point, cell l uses pilot frequency sequence akUser k can be used with user those of in its adjacent cell
Identical uplink pilot sequence ak。
B, situation 2：
If using pilot tone a in adjacent (L-1) a cell of cell lkThose of sequence user is not transmitted using DTX
Pattern (i.e. Tb=0), then the base station of cell l is that pilot tone a is used in this cell at this timekThe user k of sequence configure one it is short-term
DTX transmission modes pl,k(without notifying its adjacent base station), and the user is notified to enter DTX transmission modes pl,k.Receive the configuration
After information, which enters DTX transmission modes pl,k。
Then, base station BS calculates separately p in cell ll,kTransmission signal during p 'l,kNot during pilot signal transmitted
p″l,kIn its receive the spatial correlation matrix of signal, and determine use pilot frequency sequence a in neighboring community and this cell respectivelykShifting
Employ the feature matrix of the dominant eigenvalue at family.
Then, according to the relationship between the feature matrix of two dominant eigenvalues, to determine, user k and neighbour are small in this cell
Whether the user k in area can use identical pilot frequency sequence ak。
It is specific to determine that method is as follows：
The transmission pilot frequency sequence a of user k in cell lkPeriod p 'l,k, serving BS simultaneously receive the user transmission
Pilot frequency sequence akThe pilot frequency sequence a sent with its adjacent cell userk.Therefore, reception signal at this time is represented by：
Then, p is calculatedkSend signal during correlation matrix it is as follows：
Then, it calculatesEigenvalues DecompositionAnd thus obtain the spy for corresponding to its dominant eigenvalue
Levy vector matrix
On the other hand, user k does not send pilot frequency sequence a in cell lkPeriod p "l,k, serving BS receives only it
The pilot frequency sequence a that adjacent (L-1) community user is sentk.Therefore, reception signal at this time is expressed as：
Similarly, the correlation matrix for receiving signal is calculated：
Similarly, it calculatesEigenvalues DecompositionAnd it thus obtains corresponding to its dominant eigenvalue
Feature matrix
Finally, the base station of cell l according toWithDimension relation, determine in its this cell user k and adjacent (L-1)
Whether the user k in a cell can use identical pilot frequency sequence ak, specific as follows：
If a)Dimension withDimension it is identical, then show that following two channels are highly relevant：In cell l
Channel matrixes of the user k to the base station in channel matrix and its adjacent (L-1) cell between user k and its serving BS.This
When, cell l uses pilot frequency sequence akUser k (L-1) cells adjacent thereto in user ascending pilot frequency between there will be capable and experienced
It disturbs.So the user k in cell l cannot use uplink pilot sequence ak, need to distribute other ascending pilot frequency sequences for the user
Row.
If b)Dimension be more thanDimension, then show that the correlation of following two channels is poor：User k in cell l
Channel matrixes of the user k to the base station in channel matrix and its adjacent (L-1) cell between its serving BS.At this point, cell
L uses pilot frequency sequence akUser k (L-1) cells adjacent thereto in user ascending pilot frequency between be not present strong jamming.So
The user k in cell l can use uplink pilot sequence a at this timek。
In conclusion the selection of ascending pilot frequency and distribution method are logical in the tdd mode massive mimo systems of the present invention
The information exchange between the information exchange between user and base station and base station is crossed, tdd mode massive MIMO systems are significantly reduced
Ascending pilot frequency pollution in system；These information exchanges are likely to be standardized in following massive mimo systems.
So the present invention effectively overcomes various shortcoming in the prior art and has high industrial utilization.
The above-described embodiments merely illustrate the principles and effects of the present invention, and is not intended to limit the present invention.It is any ripe
The personage for knowing this technology can all carry out modifications and changes to above-described embodiment without violating the spirit and scope of the present invention.Cause
This, institute is complete without departing from the spirit and technical ideas disclosed in the present invention by those of ordinary skill in the art such as
At all equivalent modifications or change, should by the present invention claim be covered.
Claims (7)
1. the selection of ascending pilot frequency and distribution method in a kind of tdd mode massive mimo systems, it is characterised in that：Assuming that
The massive mimo systems of tdd mode have L cell, each base station to have M root antennas, be up to K uplink pilot sequence pilot tone
Sequence ak, k=1,2 ..., K have K user in each cell；Each base station is by K uplink pilot sequence akDistribute to the K in cell
A user, user k use pilot frequency sequence ak；
The selection of ascending pilot frequency includes the following steps with distribution method：
Step S1：Assuming that using pilot frequency sequence a in cell lkUser k DTX patterns be pl,k, cell l is by the correlation of this cell
Pilot tone use information is with the format { ID of cell l：(user's k uplink pilot sequences akSerial number, user k DTX patterns pl,k, k=
1,2 ..., K) interactive to adjacent (L-1) a cell；
Step S2：When the base station of cell l receive the associated pilot use information from adjacent (L-1) a cell { cell j's
ID：(user's k uplink pilot sequences akSerial number, the DTX patterns p of user kj,k, k=1,2 ..., K), j=1 ..., l-1, l+
1 ..., L } after, according in this cell and neighboring community use pilot frequency sequence akUser DTX patterns, calculate adjacent (L-1) it is a
Pilot frequency sequence a is used in cellkUser send signal during union, obtain in adjacent (L-1) a cell use pilot tone
Sequence akTotal DTX patterns, and calculate total DTX patternsSupplementary set
Assuming that the base station of cell l receives T in the total inspection timepA reception sample of signal, whereinTransmission signal during
In have TaA reception sample of signal, andTransmission signal during in have Tb=(Tp-Ta) a reception sample of signal；
According to TaAnd TbRelationship determine in this cell use pilot frequency sequence akUser k whether can in adjacent (L-1) a cell
Use pilot frequency sequence akUser use identical uplink pilot sequence ak。
2. the selection of ascending pilot frequency and distribution method in tdd mode massive mimo systems according to claim 1,
It is characterized in that：In the step S2, the uplink received signal of the base station of cell lFor
Wherein, ρpIndicate the transmission power of ascending pilot frequency, Hl,jIt indicates to use pilot frequency sequence a in cell jkUser and cell l
Channel matrix between base station,For additive white Gaussian noise.
3. the selection of ascending pilot frequency and distribution method in tdd mode massive mimo systems according to claim 1,
It is characterized in that：If TbLength can calculate in cell l use pilot frequency sequence akUser uplink base station at receive letter
Number spatial correlation matrix, then the base station of cell l calculate separatelyTransmission signal during andTransmission signal during in
Receive the spatial correlation matrix of signal；
Transmission signal during, base station receives only the pilot signal transmitted of user in its adjacent (L-1) a cell, connects
The collection of letters number is expressed as
Send signal during spatial correlation matrix it is as follows：
Eigenvalues Decomposition beTo obtain the feature matrix corresponding to dominant eigenvalue
Transmission signal during, base station receives only the pilot signal that user k in its this cell is sent, that is, receives signal
It is expressed as
Send signal during spatial correlation matrix it is as follows：
Eigenvalues Decomposition beTo obtain the feature matrix corresponding to dominant eigenvalue
The base station of cell l according toWithRelationship, determine in cell l user k can with pilot frequency sequence is used in neighboring community
akUser use identical pilot frequency sequence ak。
4. the selection of ascending pilot frequency and distribution method in tdd mode massive mimo systems according to claim 3,
It is characterized in that：The base station of cell l according toWithRelationship, determine in cell l user k can in neighboring community using leading
Frequency sequence akUser use identical pilot frequency sequence akWhen,
IfCell l uses pilot frequency sequence akUser cannot in neighboring community use pilot frequency sequence ak's
User uses identical uplink pilot sequence ak；
IfCell l uses pilot frequency sequence akUser k can in neighboring community use pilot frequency sequence ak's
User uses identical uplink pilot sequence ak。
5. the selection of ascending pilot frequency and distribution method in tdd mode massive mimo systems according to claim 1,
It is characterized in that：If using pilot tone a in adjacent (L-1) a cell of cell lkThe user of sequence using DTX without transmitting mould
Formula, then the base station of cell l is that pilot tone a is used in this cell at this timekThe user k of sequence configures a short-term DTX transmission mode
pl,k, and the user is notified to enter DTX transmission modes pl,k；After receiving the configuration information, which enters the DTX transmission modes
pl,k；
Base station calculates separately p in cell ll,kTransmission signal during p 'l,kNot p during pilot signal transmitted "l,kMiddle reception letter
Number spatial correlation matrix, and determine use pilot frequency sequence a in neighboring community and this cell respectivelykMobile subscriber main feature
The feature matrix of value；
The use in this cell in user k and neighboring community is determined according to the relationship between the feature matrix of two dominant eigenvalues
Whether family k can use identical pilot frequency sequence ak。
6. the selection of ascending pilot frequency and distribution method in tdd mode massive mimo systems according to claim 5,
It is characterized in that：User k and neighboring community in this cell are determined according to the relationship between the feature matrix of two dominant eigenvalues
In user k whether can use identical pilot frequency sequence akWhen,
The transmission pilot frequency sequence a of user k in cell lkPeriod p 'l,k, serving BS simultaneously receive the user transmission pilot tone
Sequence akThe pilot frequency sequence a sent with adjacent cell userk, receive signal and be expressed as：
pkSend signal during correlation matrix it is as follows：
Eigenvalues Decomposition beAnd obtain the feature matrix corresponding to its dominant eigenvalue
User k's does not send pilot frequency sequence a in cell lkPeriod p "l,k, serving BS receives only its adjacent (L-1) cell and uses
The pilot frequency sequence a that family is sentk；Signal is received to be expressed as：
Receive signal correlation matrix be：
Eigenvalues Decomposition beAnd obtain the feature matrix corresponding to its dominant eigenvalue
The base station of cell l according toWithDimension relation, determine in its this cell in user k and adjacent (L-1) a cell
Whether user k can use identical pilot frequency sequence ak。
7. the selection of ascending pilot frequency and distribution method in tdd mode massive mimo systems according to claim 6,
It is characterized in that：The base station of cell l according toWithDimension relation, determine that user k and adjacent (L-1) are a small in its this cell
Whether the user k in area can use identical pilot frequency sequence akWhen,
IfDimension withDimension it is identical, cell l use pilot frequency sequence akUser cannot be used with neighboring community
Pilot frequency sequence akUser use identical uplink pilot sequence ak；
IfDimension be more thanDimension, cell l use pilot frequency sequence akUser can in neighboring community use pilot tone
Sequence akUser use identical uplink pilot sequence ak。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410838686.1A CN105790912B (en) | 2014-12-26 | 2014-12-26 | The selection of ascending pilot frequency and distribution method in TDD mode m assive MIMO systems |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410838686.1A CN105790912B (en) | 2014-12-26 | 2014-12-26 | The selection of ascending pilot frequency and distribution method in TDD mode m assive MIMO systems |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105790912A CN105790912A (en) | 2016-07-20 |
| CN105790912B true CN105790912B (en) | 2018-10-19 |
Family
ID=56389156
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410838686.1A Expired - Fee Related CN105790912B (en) | 2014-12-26 | 2014-12-26 | The selection of ascending pilot frequency and distribution method in TDD mode m assive MIMO systems |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105790912B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116582225B (en) * | 2023-07-12 | 2023-11-03 | 极芯通讯技术(南京)有限公司 | Method, device and storage medium for determining validity of discontinuous transmission signal |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102545983A (en) * | 2012-01-09 | 2012-07-04 | 清华大学 | Processing method and device for pilot frequency in multi-point cooperative transmission system |
| CN103634816A (en) * | 2013-11-01 | 2014-03-12 | 南京邮电大学 | Method for eliminating pilot pollution-based interference in multi-cell massive MIMO (Multiple Input Multiple Output) |
| CN104009947A (en) * | 2014-06-19 | 2014-08-27 | 华中科技大学 | Pilot signal sending and channel estimation method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103220028B (en) * | 2012-01-21 | 2016-03-30 | 华为技术有限公司 | Pilot signal transmitting method, channel estimation methods, Apparatus and system |
-
2014
- 2014-12-26 CN CN201410838686.1A patent/CN105790912B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102545983A (en) * | 2012-01-09 | 2012-07-04 | 清华大学 | Processing method and device for pilot frequency in multi-point cooperative transmission system |
| CN103634816A (en) * | 2013-11-01 | 2014-03-12 | 南京邮电大学 | Method for eliminating pilot pollution-based interference in multi-cell massive MIMO (Multiple Input Multiple Output) |
| CN104009947A (en) * | 2014-06-19 | 2014-08-27 | 华中科技大学 | Pilot signal sending and channel estimation method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105790912A (en) | 2016-07-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105790913B (en) | The selection and distribution method of ascending pilot frequency in fdd mode massive-MIMO system | |
| CN103312389B (en) | A kind of multiuser interference suppression method, terminal and base station | |
| CN101388752B (en) | Uplink transmission method, terminal and base station based on time division duplexing system | |
| CN103326761B (en) | Channel condition information processing method and processing device | |
| Kim et al. | Hierarchical maritime radio networks for internet of maritime things | |
| CN105122667A (en) | Method and apparatus for providing control information for fractional beamforming in a wireless communication system | |
| EP3185434B1 (en) | Method and device for beamforming | |
| CN103997394A (en) | Multi-cell coordination large-scale MIMO pilot frequency multiplexing transmission method | |
| US11329699B2 (en) | Disturbance mitigation | |
| CN107431589A (en) | Method and apparatus for handling and distributing uplink pilot | |
| CN105706375B (en) | The method and apparatus that topological pilot pollution for extensive mimo system is eliminated | |
| Lee et al. | Transceiver design based on interference alignment in MIMO interfering broadcast channels | |
| CN106936552A (en) | Uplink pilot sequence distribution method and base station in extensive mimo system | |
| CN108781096A (en) | Wireless communication system, wireless base station and user equipment | |
| Cheikh et al. | Analytical joint processing multi-point cooperation performance in Rayleigh fading | |
| CN101156335B (en) | Wireless base station apparatus | |
| CN104683005A (en) | Interference suppression method and interference suppression device | |
| CN103384228A (en) | Continuous pre-coding and user selection united algorithm for multi-user MIMO (Multiple-Input Multiple-Output) broadcast channel | |
| CN104734767A (en) | Multi-cell partial collaboration downlink MIMO (multiple input multiple output) robust double-layer precoding method | |
| CN101378282B (en) | Method and apparatus for processing signal of multi-input multi-output system | |
| CN101378281B (en) | Method and apparatus for processing signal of multi-input multi-output system | |
| Zirwas et al. | Key solutions for a massive MIMO FDD system | |
| CN105790912B (en) | The selection of ascending pilot frequency and distribution method in TDD mode m assive MIMO systems | |
| Li et al. | NOMA-aided massive MIMO downlink with distributed antenna arrays | |
| CN102077484B (en) | Synthesized beam-forming method and system for SC MBMS transmission |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20181019 Termination date: 20181226 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |