CN1481099A - Method of matched filter bank for estimating wave direction of maultiple paths signals in CDMA and its device - Google Patents
Method of matched filter bank for estimating wave direction of maultiple paths signals in CDMA and its device Download PDFInfo
- Publication number
- CN1481099A CN1481099A CNA031496555A CN03149655A CN1481099A CN 1481099 A CN1481099 A CN 1481099A CN A031496555 A CNA031496555 A CN A031496555A CN 03149655 A CN03149655 A CN 03149655A CN 1481099 A CN1481099 A CN 1481099A
- Authority
- CN
- China
- Prior art keywords
- signal
- user
- matched filter
- filter banks
- arrival
- 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.)
- Granted
Links
Images
Abstract
First, separation of user multipaths signals is carried out and the output of matched filter group under asynchronous multipaths channels is calculated by using connected matched filter group behind array antenna. Next, covariance matrix of user multipaths signals is evaluated from output of matched filter group. Then, calculation of covariance matrix eigenvalue decomposion is carried out. Finally, based on main eigenvector of covariance matrix eigenvalue decomposion, estimating wave distination direction of user multipaths signals is realized. The device includes (1) separation of user multipaths signals based on matched filter group and calculation module, (2) estimator of wave destination direction of user multipaths signals. The method and device is simple and feasible as well as suitable for estimating wave destination direction of user multipaths signals in array antenna of CDMA system.
Description
Technical field
The invention belongs to code division multiple access cdma cellular field of wireless communications.
Background technology
The cdma cellular communication technology is simple with its frequency planning, power system capacity is big, ability of anti-multipath is strong, good communication quality, electromagnetic interference are little etc., and characteristics demonstrate huge development potentiality, are the mainstream technologys of future mobile communications.If particularly in cdma system, use array antenna can improve capacity, spectrum efficiency, communication quality and the coverage of system significantly and high-precision wireless location service is provided.The direction of arrival of user multipaths signal estimates that the user radio location technology that wave beam to down link forms, reduces to disturb and estimates based on angle has important function in the array antenna CDMA system, is one of key technology of array antenna CDMA system.
In the past few decades, proposed many signal direction of arrival DOA algorithm for estimating, be commonly referred to traditional DOA algorithm for estimating based on aerial array.Traditional DOA algorithm for estimating such as multiple signal classification method MUSIC and require the array number of aerial array more than signal number by invariable rotary technology estimated signal parameter ESPRIT algorithm, and signal source spatially can not be overlapping, otherwise aerial array can't effectively be estimated the DOA of signal source.
The up channel of cdma system is generally asynchronous multipath channel, and user job is in identical frequency range.Tens users are arranged in the typical cellular sub-district usually, and each user's signal can produce many single sub path again, makes traditional DOA algorithm for estimating based on aerial array can not directly apply in the array antenna CDMA system.
Summary of the invention
Technical problem solved by the invention is to propose a kind of matched filter banks CDMA multipath method for estimating signal wave direction and device.This method can effectively be differentiated the direction of arrival with the estimating user multipath signal.The device based on said method that the present invention proposes is simple, and the direction of arrival that is very suitable for array antenna CDMA system user multipath signal is estimated.
Technical scheme of the present invention-matched filter banks CDMA multipath method for estimating signal wave direction:
The output that at first utilizes the matched filter banks that connects after the array antenna array element to carry out the separation of user multipaths signal and calculate matched filter banks under the asynchronous multipath channel, secondly directly utilize the covariance matrix of the output estimating user multipath signal of matched filter banks, and then carry out the calculating of covariance matrix feature decomposition, realize at last estimating based on the user multipaths signal direction of arrival of covariance matrix feature decomposition principal eigenvector.
Its process is as follows:
At first user multipaths signal is separated and the output of calculating matched filter banks: utilize matched filter banks user multipaths signal effectively to be separated and utilize the output of the property calculation matched filter banks that is associated of transmission signals signature waveform under the asynchronous multipath channel based on matched filter banks.
Secondly estimate covariance matrix: to isolated user's multipath signal ask its Estimation of covariance matrix, obtain the user multipaths signal Estimation of covariance matrix.
Then, calculating user multipaths signal covariance matrix is carried out feature decomposition, obtain the principal eigenvector of corresponding eigenvalue of maximum.
At last, realize the estimation of user multipaths signal direction of arrival: after obtaining principal eigenvector, utilize multiple signal classification method estimating user multipath signal direction of arrival based on principal eigenvector.
Matched filter banks CDMA multipath signal direction of arrival estimation unit.This device comprises: the user multipaths signal based on matched filter banks separates and computing module A and user multipaths signal direction of arrival estimator B two parts, separate and the input of the input termination array antenna baseband sampling signal of computing module A based on the user multipaths signal of matched filter banks, based on the input of the output termination user multipaths signal direction of arrival estimator B of the user multipaths signal separation of matched filter banks and computing module A.
Below to the invention in each composition discussed respectively.
1. the user multipaths signal based on matched filter banks separates and calculating
A. the received signal of array
Investigate one and go up line asynchronous multipath channel array antenna CDMA system.Be without loss of generality, suppose that further mobile channel is the frequency selectivity slow fading channel, the correlation time of channel is much larger than symbol period.Certain cellular cell has K user launching bpsk signal by multipath channel separately in the supposing the system.Like this, k the N bit signal that the user launched can be expressed as:
In [formula 1] formula, A
kThe amplitude of representing k subscriber signal, b
k(n) { 1 ,+1} represents the n bit signal of general transmission such as k user, c to ∈
k(t) k user's of expression frequency spreading wave has
In [formula 2] formula, c
Kg∈ 1, and+1} (g=0 ..., G-1) be its spreading code, p (t) is that width is Y
cCut general pulse, T
bBe the bit interval time, G is defined as G=T
b/ T
cSpreading gain, its frequency spreading wave has normalized energy, promptly
Equally, suppose that the information bit that each user launches is independently, the information bit of different user also is independently.
Suppose that base station array antenna has M array element, customer mobile terminal adopts single antenna.Like this, the baseband multi-path channel between k user transmitter and base station receiver can represent that its impulse response vector is with the many output of single input SIMO channels
[formula 3] wherein, L is each user's a multipath number, α
KlAnd τ
K, lBe respectively the multiple decay and the time delay of k user l footpath signal,
Be that corresponding k user l footpath signal direction of arrival is θ
K, l(t) array vector.
Like this, base station array antenna receives total signal and is
[formula 4]
Wherein, * represents convolution, μ
K, l=A
kα
K, lBe the complex magnitude of k user l footpath signal of being received, w (t) is that average is 0, and covariance matrix is σ
2I
MThe additive white Gaussian noise vector, I
MIt is the unit matrix of M * M.
Be defined as follows vector
Wherein,
Wherein,
Wherein,
Wherein,
o
LBe complete 1 column vector in L * 1, represents that Kronecker is long-pending.
Like this, the base station array antenna that provides of formula 4 receives total signal and can be expressed as by matrix form
[formula 5]
B. the calculating of matched filter banks output
The output of all users and multipath composition thereof matched filter banks on all array elements of array antenna can provide sufficient statistical information to detecting numerical chracter.At t ∈ [nT
b, (n+1) T
b) time interval M * 1 dimension bank of filters of being matched with k user l footpath frequency spreading wave is output as
[formula 6]
Because the characteristic of hypothesis channel is that Rayleigh changes fading channel slowly, usually multidiameter delay τ
K, lIn-less-than symbol interval T always
bIn this case, n symbol of the signature waveform that directly transmits by l of k user only is associated by (n-l), n, (n+l) individual symbol of l footpath transmission feature waveform with k user.Therefore, formula 6 can be written as
[formula 7]
Wherein,
With
[formula 8]
Diagonal matrix
Be the correlation matrix of frequency spreading wave between different user and footpath, be defined as
Wherein,
[formula 9]
The time invariant features waveform and the total in-less-than symbol interval T of multidiameter delay
bSituation under, obtain easily
Therefore, formula 9 can further push away into
With
If it is known supposing the multidiameter delay of different user, R
K ', l ', k, l (n)(1), R
K ', l ', k, l (n)And R (0),
K ', l ', k, l (n)(1) can be calculated, because cdma system user's signature waveform is known in advance.
Can easily see w from formula 10
K, l (n)Remain the additive white Gaussian noise vector, its average still is 0, and variance is σ
2I
MR
K, l, k, l (n)(0).
2. the user multipaths signal direction of arrival is estimated
A. the calculating of covariance matrix
Output y based on formula 7 matched filter banks
K, l (n), the direction of arrival θ of k user l footpath signal
K, lCan estimate by the MUSIC class algorithm of one of subspace algorithm.Comparing yard matched filter banks will disturb and noise power with the multiple access that spreading gain G suppresses on each bay with the power of desired signal.Like this, corresponding covariance matrix R
Y, k, lThe e of principal eigenvector
1, k, lTo be the direction of arrival θ of k user l footpath signal
K, lProvide one well to estimate.Covariance matrix R
Y, k, lBe defined as
[formula 11] wherein, E{} represent the expectation.
In practice, R
Y, k, lExact value be unavailable, must estimate by the data that receive.Covariance matrix R
Y, k, lCan form true R by Q continuous observation or sampling based on the measurement model of formula 7
Y, k, lEmploying estimate
Promptly
[formula 12]
B. the feature decomposition of covariance matrix
To resulting sampling covariance matrix
Carry out feature decomposition, obtain covariance matrix R
Y, k, lPrincipal eigenvector e
1, k, lEstimation
C. the user multipaths signal direction of arrival is estimated
At last, realize the estimation of user multipaths signal direction of arrival.In the estimation that obtains k user l footpath signal covariance matrix feature decomposition principal eigenvector
After, can realize k user l footpath signal direction of arrival θ
K, lEstimation
Concrete steps are:
At first, structure spatial spectrum function,
[formula 13] wherein, reciprocity pitch arrays antenna has
Then, search volume spectral function P
MUThe spectrum peak direction of arrival that just can obtain corresponding k user l footpath signal estimate.The direction of arrival θ of corresponding k user l footpath signal
K, lBe estimated as
[formula 13]
Beneficial effect of the present invention: at first, because the estimation of user multipaths signal direction of arrival is that directly output realizes that therefore, its topmost advantage is exactly that structure, method are simple based on matched filter banks.Secondly, method does not require the number of signals of the array number of array antenna more than user and multipath thereof; Simultaneously, method does not need to detect the signal source number of user and multipath thereof, and these are that traditional multiple signal classification method is necessary.In addition, owing to only need the single spatial spectrum peak of search, therefore, corresponding estimated result is very reliable.These all make the present invention be very suitable for practical application.
Description of drawings
Fig. 1 is the device general diagram.
Fig. 2 is a matched filter banks schematic diagram after each array element.
Fig. 3-the 6th, the performance legend of Wave arrival direction estimating method that the present invention carries.
Embodiment
The present invention is described in further detail below in conjunction with accompanying drawing.
The method according to this invention is applicable to the CDMA mobile communication system of any employing array antenna.
Fig. 1 has provided this method and has been applied to the device detailed structure schematic diagram that the array antenna direct sequence spread spectrum codes is divided multiple access DS-CDMA mobile communication system.
This device comprises: the user multipaths signal based on matched filter banks separates and computing module A and user multipaths signal direction of arrival estimator B two parts composition, separate and the input of the input termination array antenna baseband sampling signal of computing module A based on the user multipaths signal of matched filter banks, based on the input of the output termination user multipaths signal direction of arrival estimator B of the user multipaths signal separation of matched filter banks and computing module A.
User multipaths signal direction of arrival estimator B comprises user multipaths signal correlation matrix computing module B101, covariance matrix feature decomposition module B102, user multipaths signal direction of arrival estimation module B103.Wherein user multipaths signal separation and computing module A, user multipaths signal correlation matrix computing module B101, covariance matrix feature decomposition module B102, the user multipaths signal direction of arrival estimation module B103 based on matched filter banks is connected in series successively in proper order.
Concrete signal processing is as follows: at first, the base-band analog signal that each array element of array antenna is received into is after modulus A/D conversion, become digital signal, the user multipaths signal that enters then based on matched filter banks separates and calculator modules A, this module realizes the separation of user multipaths signal according to the different delay of user multipaths signal by matched filter banks, calculates the desired user multipath signal y of matched filter banks output simultaneously according to formula 7
K, l (n), its result offers user multipaths signal correlator block B101.In user multipaths signal correlator block B101, the continuous observation of Q or the sampling line correlation of going forward side by side is carried out in the output of matched filter banks calculate and form the true covariance matrix R of desired user multipath signal
Y, k, lEmploying estimate
Covariance matrix feature decomposition module B102 receives the output of user multipaths signal correlator block B101 and the employing of desired user multipath signal covariance matrix is estimated
Matrix carries out feature decomposition, obtains principal eigenvector e
1, k, lEstimation
And will
Be input to user multipaths signal direction of arrival estimator module B103.User multipaths signal direction of arrival estimator module B103 receives
After, obtain desired user multipath signal direction of arrival θ
K, lEstimation
Fig. 3-6 has provided based on array antenna DS-CDMA system user multipath signal direction of arrival estimation under the asynchronous multipath channel of matched filter banks output the result of signal to noise ratio snr.Provided the influence of number of users, spread processing gain and array structure respectively to estimated performance.For estimate estimation performance to 50 times independently simulation result carried out on average, and adopted standard error SD as evaluation index, it is defined as
[formula 14] wherein, U is the number of times of independent experiment.
Concrete simulated conditions is as follows: the employing array element distance is that the evenly equally spaced 5 array element Straight Wire Antenna arrays in half wavelength lambda/2 receive the BPSK multipath signal.Be without loss of generality, suppose that channel is two footpath rayleigh fading channels, each directly has identical energy, and the relative delay of multipath signal is in a mark space.Spreading code is that the gain of picked at random is 64 frequency expansion sequence, obtains Estimation of covariance matrix with 20 times observations or sampling length
Might as well suppose to have respectively 3 and 6 users to be randomly dispersed in the sub-district, user's footpath direction of arrival that expectation is estimated is 27 °.
As seen from Figure 3, method proposed by the invention is estimated very effective to the direction of arrival of user multipaths signal, and its result is suitable for practical application.Though along with the increase estimation performance of number of users can descend to some extent, because the effect of spreading gain, the influence that number of users increases will be limited.The result of Fig. 4 has further shown this point.As can be seen from Figure 4, when spreading gain increased, owing to suppress the enhancing of multiple access interference capability, estimation performance significantly improved.
Fig. 5 and Fig. 6 have shown the influence of array structure to estimated performance.Fig. 5 shows the increase along with array number, and estimation performance can improve.Particularly can observe from Fig. 6, when strengthen between array element apart from the time, estimation performance can be significantly improved.This be since in both cases the resolving power of aerial array all be enhanced.
It is worthy of note, even when two of different user or many strips directly arrive the direction of arrival of aerial array when identical, because it is that each CDMA user has been assigned with unique spreading code that method has been utilized the intrinsic characteristic of CDMA signal, therefore the direction of arrival in each son footpath still can effectively be estimated in this case.
Claims (5)
1. matched filter banks CDMA multipath method for estimating signal wave direction, the output that it is characterized in that at first utilizing the matched filter banks that connects after the array antenna array element to carry out the separation of user multipaths signal and calculate matched filter banks under the asynchronous multipath channel, secondly directly utilize the covariance matrix of the output estimating user multipath signal of matched filter banks, and then carry out the calculating of covariance matrix feature decomposition, realize at last estimating based on the user multipaths signal direction of arrival of covariance matrix feature decomposition principal eigenvector.
2. matched filter banks CDMA multipath method for estimating signal wave direction according to claim 1, the calculating that it is characterized in that matched filter banks output are the characteristic realizations that is associated that utilizes transmission signals signature waveform under the asynchronous multipath channel.
3. according to the described matched filter banks CDMA multipath of claim 1 method for estimating signal wave direction, it is characterized in that utilizing multiple signal classification method estimating user multipath signal direction of arrival based on principal eigenvector.
4. matched filter banks CDMA multipath signal direction of arrival estimation unit, it is characterized in that this device is by separating based on the user multipaths signal of matched filter banks and computing module A and user multipaths signal direction of arrival estimator B two parts are formed, separate and the input of the input termination array antenna baseband sampling signal of computing module A based on the user multipaths signal of matched filter banks, based on the input of the output termination user multipaths signal direction of arrival estimator B of the user multipaths signal separation of matched filter banks and computing module A.
5. according to the described matched filter banks CDMA multipath of claim 4 signal direction of arrival estimation unit, it is characterized in that user multipaths signal direction of arrival estimator (B) comprises user multipaths signal correlation matrix computing module (B101), covariance matrix feature decomposition module (B102), user multipaths signal direction of arrival estimation module (B103), wherein the user multipaths signal based on matched filter banks separates and computing module (A), user multipaths signal correlation matrix computing module (B101), covariance matrix feature decomposition module (B102), user multipaths signal direction of arrival estimation module (B103) order successively is connected in series.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN 03149655 CN1209891C (en) | 2003-08-06 | 2003-08-06 | Method of matched filter bank for estimating wave direction of maultiple paths signals in CDMA and its device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN 03149655 CN1209891C (en) | 2003-08-06 | 2003-08-06 | Method of matched filter bank for estimating wave direction of maultiple paths signals in CDMA and its device |
Publications (2)
Publication Number | Publication Date |
---|---|
CN1481099A true CN1481099A (en) | 2004-03-10 |
CN1209891C CN1209891C (en) | 2005-07-06 |
Family
ID=34156344
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN 03149655 Expired - Fee Related CN1209891C (en) | 2003-08-06 | 2003-08-06 | Method of matched filter bank for estimating wave direction of maultiple paths signals in CDMA and its device |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN1209891C (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN100345402C (en) * | 2004-07-06 | 2007-10-24 | 中兴通讯股份有限公司 | High resolution estimation method for incoming wave direction of mobile communication system |
CN101292451B (en) * | 2005-10-17 | 2011-10-12 | Nxp股份有限公司 | Signal-to-interference + noise ratio estimator and method, mobile terminal having this estimator |
CN103260240A (en) * | 2013-05-23 | 2013-08-21 | 北京邮电大学 | Scattering information source locating method based on distribution matching in large-scale MIMO system |
CN104820216A (en) * | 2015-05-08 | 2015-08-05 | 西北工业大学 | Multipath signal angle-of-arrival estimation method based on array response rotation invariance |
-
2003
- 2003-08-06 CN CN 03149655 patent/CN1209891C/en not_active Expired - Fee Related
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN100345402C (en) * | 2004-07-06 | 2007-10-24 | 中兴通讯股份有限公司 | High resolution estimation method for incoming wave direction of mobile communication system |
CN101292451B (en) * | 2005-10-17 | 2011-10-12 | Nxp股份有限公司 | Signal-to-interference + noise ratio estimator and method, mobile terminal having this estimator |
CN103260240A (en) * | 2013-05-23 | 2013-08-21 | 北京邮电大学 | Scattering information source locating method based on distribution matching in large-scale MIMO system |
CN103260240B (en) * | 2013-05-23 | 2016-06-01 | 北京邮电大学 | Based on the scattering signal source locating method of distribution coupling in extensive MIMO |
CN104820216A (en) * | 2015-05-08 | 2015-08-05 | 西北工业大学 | Multipath signal angle-of-arrival estimation method based on array response rotation invariance |
CN104820216B (en) * | 2015-05-08 | 2017-03-08 | 西北工业大学 | Multipath signal direction of arrival estimation method based on array response rotational invariance |
Also Published As
Publication number | Publication date |
---|---|
CN1209891C (en) | 2005-07-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN101291165B (en) | Sequence detecting method and apparatus for multi-antenna system | |
CN101467358B (en) | Method and system for detecting preambles in a multi-cell system | |
CN1108071C (en) | Signal processing method for terminal in CDMA mobile communication system | |
CN102364885A (en) | Frequency spectrum sensing method based on signal frequency spectrum envelope | |
CN1481100A (en) | Method of time space solution for estimating wave diretion of maultiple paths signals in correlative CDMA and its device | |
CN101056285A (en) | Parallel interference elimination channel estimation method and device in the radio mobile communication system | |
CN1139192C (en) | Adaptive array up receiving method and receiving for radio communication system | |
CN1520077A (en) | Method for estimating channel containing multiple code sets in time slot CDMA system | |
CN1481099A (en) | Method of matched filter bank for estimating wave direction of maultiple paths signals in CDMA and its device | |
CN100512047C (en) | Estimating method of reach direction of user signal wave of array antenna MC-CDMA system | |
CN100385810C (en) | Two-dimensional spread-spectrum chip-level differential detection method | |
CN1199052C (en) | Method of raising accuracy estimation of received signal wave arrival direction | |
CN1180542C (en) | Ruike receiver multipath searching device using energy estimation and multipath searching method | |
CN100345402C (en) | High resolution estimation method for incoming wave direction of mobile communication system | |
CN1054251C (en) | Method for testing spectrum spreading signal in code division multi-address radio communication system | |
CN100536379C (en) | Space-time spectrum extending method and circuit using generalized complementary matching filter | |
CN1225209A (en) | A delay estimation method and a receiver | |
CN1155178C (en) | Method and equipment for up receiving array in wireless communicaltion system | |
CN1921324B (en) | Multipath searching method for code division multiple access communication system | |
CN1561006A (en) | Correlated receiver and signal receiving method for super-broad band radio communication system | |
CN1585318A (en) | Space characteristic extracting and signal reaching direction estimating method for CDMA wireless telecommunication | |
CN1145297C (en) | Code filtering down beam forming device and method for CDMA | |
CN101106412B (en) | MC-DS-CDMA uplink receiving method and device for array antenna | |
CN100512083C (en) | Uplink receiving method for array antenna MT-CDMA system | |
CN1816026A (en) | Channel estimation method and apparatus |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
C06 | Publication | ||
PB01 | Publication | ||
C10 | Entry into substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
C14 | Grant of patent or utility model | ||
GR01 | Patent grant | ||
C19 | Lapse of patent right due to non-payment of the annual fee | ||
CF01 | Termination of patent right due to non-payment of annual fee |