CN104753831A - Method and device for detecting quantity of adjacent region antenna ports - Google Patents

Abstract

The invention provides a method for detecting quantity of adjacent region antenna ports. The method comprises the steps of acquiring frequency domain channel estimation according to a received signal of a frequency domain reference signal (RS) and a reference signal of a local RS; performing inverse discrete Fourier transform on the frequency domain channel estimation so as to obtain time domain channel estimation; computing the time domain signal-noise ratio of each adjacent region antenna port according to the time domain channel estimation; and judging the quantity of the adjacent region antenna ports according to the time domain signal-noise ratios of all the adjacent region antenna ports. The method can detect the exact quantity of antenna ports interfering an adjacent region presently in real time, provides necessary prior information for cell specific reference signal (CRS) interference elimination of the adjacent region, and helps to further improve the co-frequency anti-interference capacity of the terminal.

Description

A kind of method and device detecting adjacent area antenna port number

Technical field

The present invention relates to communication technique field, particularly a kind of method and device detecting adjacent area antenna port number.

Background technology

In LTE system, for co-channel interference, prior art adopts the method for resource coordination between base station to solve, and is called for short Inter-Cell Interference Coordination (ICIC, Inter-Cell Interference Coordinate).Its basic thought by managing radio resources, presence of intercell interference is controlled, and is a kind ofly to consider that resource in multiple community uses and the situation such as load and the multiple cell radio resource management scenarios of carrying out.

But, the interference of inter-cell traffic data can only be solved by ICIC technology preferably, interfering with each other of minizone reference signal (RS, Reference Signal) can not be solved.For typical cell reference signals (CRS, Cell specific Reference Signal), base station side is all that full bandwidth sends, and for this kind of interference signal, current interference coordination technique is insurmountable.

In LTE wireless communication system, in the interference cancellation techniques of common frequency multi-cell, first need to know adjacent area antenna port number, this information is that required prior information is eliminated in adjacent area interference.Usually, when known cell number (CellID), the local CRS signal of this community can be obtained, thus rebuild the CRS Received signal strength of this community, and carry out interference and eliminate.Before the reconstruction carrying out interference signal and elimination, be badly in need of the problem solving the detection of adjacent area antenna port number, correctly could carry out interference and eliminate.

Summary of the invention

The object of the present invention is to provide a kind of method and the device that detect adjacent area antenna port number, cannot solve to solve existing interference coordination technique the problem that minizone reference signal interferes with each other.

For solving the problems of the technologies described above, the invention provides a kind of method detecting adjacent area antenna port number, comprising:

According to the Received signal strength at frequency domain RS place and the reference signal at local RS place, obtain channel estimation in frequency domain;

Described channel estimation in frequency domain is carried out discrete fourier inversion, obtains time domain channel and estimate;

The time domain signal to noise ratio calculating each adjacent area antenna port is estimated according to described time domain channel;

The quantity of adjacent area antenna port is judged according to all adjacent area antenna port time domain signal to noise ratios.

Preferably, in the method for described detection adjacent area antenna port number, in the step obtaining channel estimation in frequency domain, adopt the Received signal strength of least square method according to frequency domain reference signal RS place and the reference signal at local reference signal place, obtain channel estimation in frequency domain.

Preferably, in the method for described detection adjacent area antenna port number, described channel estimation in frequency domain is being carried out discrete fourier inversion, obtain in the step of time domain channel estimation, by after integral number power that the dimension of described channel estimation in frequency domain to be mended into by channel estimation in frequency domain 2 by the mode of zero padding, again channel estimation in frequency domain is done to the discrete fourier inversion of the integral number power of 2, estimate to obtain time domain channel.

Preferably, in the method for described detection adjacent area antenna port number, judging in the step of the quantity of adjacent area antenna port according to all adjacent area antenna port time domain signal to noise ratios, the antenna port number preset with one after adjacent area antenna port time domain signal to noise ratio is done computing judges that thresholding compares, thus judges the quantity of adjacent area antenna port.

Preferably, in the method for described detection adjacent area antenna port number, the quantity of described adjacent area antenna is four, is judging in the step of the quantity of adjacent area antenna port according to all adjacent area antenna port time domain signal to noise ratios,

First by the time domain signal to noise ratio of the time domain signal to noise ratio of antenna port 2 and antenna port 0 with compare judgement, if antenna port 2 exists, then judge that the quantity of adjacent area antenna port is 4;

Otherwise, then by the time domain signal to noise ratio of the time domain signal to noise ratio of antenna port 1 and antenna port 0 with compare judgement, if antenna port 1 exists, then judge that the quantity of adjacent area antenna port is 2; Otherwise then the quantity of adjacent area antenna port is 1.

Accordingly, the present invention also provides a kind of device detecting adjacent area antenna port number, comprising:

Channel estimation in frequency domain unit, for according to the Received signal strength at frequency domain RS place and the reference signal at local RS place, obtains channel estimation in frequency domain;

Discrete fourier inversion converter unit, for described channel estimation in frequency domain is carried out discrete fourier inversion, obtains time domain channel and estimates;

Snr computation unit, for estimating according to described time domain channel the time domain signal to noise ratio calculating each adjacent area antenna port;

Antenna port number judging unit, for judging the quantity of adjacent area antenna port according to all adjacent area antenna port time domain signal to noise ratios.

Preferably, in the device of described detection adjacent area antenna port number, in channel estimation in frequency domain unit, adopt the Received signal strength of least square method according to frequency domain reference signal RS place and the reference signal at local reference signal place, obtain channel estimation in frequency domain.

Preferably, in the device of described detection adjacent area antenna port number, in discrete fourier inversion converter unit, by after integral number power that the dimension of described channel estimation in frequency domain to be mended into by channel estimation in frequency domain 2 by the mode of zero padding, again channel estimation in frequency domain is done to the discrete fourier inversion of the integral number power of 2, estimate to obtain time domain channel.

Preferably, in the device of described detection adjacent area antenna port number, in antenna port number judging unit, the antenna port number preset with after adjacent area antenna port time domain signal to noise ratio is done computing judges that thresholding compares, thus judges the quantity of adjacent area antenna port.

The method of detection adjacent area antenna port number provided by the invention and device, there is following beneficial effect: the present invention detects the antenna port number that current interference adjacent area is definite in real time, disturb for adjacent area CRS the process such as elimination to provide necessary prior information, contribute to the same frequency antijamming capability improving terminal further.

Accompanying drawing explanation

Fig. 1 is the schematic diagram that the present invention detects the device of adjacent area antenna port number;

Fig. 2 is the schematic diagram that the present invention detects the method for adjacent area antenna port number;

Fig. 3 is the method testing process schematic diagram of the detection adjacent area antenna port number of the embodiment of the present invention 1.

Embodiment

Below in conjunction with the drawings and specific embodiments, the method for the detection adjacent area antenna port number that the present invention proposes and device are described in further detail.According to the following describes and claims, advantages and features of the invention will be clearer.It should be noted that, accompanying drawing all adopts the form that simplifies very much and all uses non-ratio accurately, only in order to object that is convenient, the aid illustration embodiment of the present invention lucidly.

Along with development and the LTE(Long Term Evolution of wireless communication technology, Long Term Evolution) communication system rise in the world, Radio Resource day is becoming tight.In order to improve the availability of frequency spectrum of LTE system, identical networking becomes a kind of effective solution.In the LTE system of identical networking, there are other communities multiple with its use same frequency in each home cell, thus mutually between form co-channel interference.

In LTE system, channel estimating is MIMO(multiple-input, multiple-output) basis of the key technology such as detection, measurement, feedback.Usually, reference signal (RS, Reference Signal) is used to carry out channel estimating in LTE.These RS determine for fixing Cell ID, and that is for this co-channel interference signal determined of RS, we can carry out rebuilding and eliminating.But, before interference being rebuild and eliminates, first need to detect these interference and whether exist, and there are how many antenna ports etc. in interfered cell.

Please refer to Fig. 1, it is the schematic diagram that the present invention detects the device of adjacent area antenna port number.As shown in Figure 1, the invention provides a kind of device detecting adjacent area antenna port number, solve the problem of the antenna port number detecting adjacent area how in real time, the device of described detection adjacent area antenna port number comprises: channel estimation in frequency domain unit 101, discrete fourier inversion converter unit 102, snr computation unit 103 and antenna port number judging unit 104;

Described channel estimation in frequency domain unit 101, for according to the Received signal strength at frequency domain RS place and the reference signal at local RS place, obtains channel estimation in frequency domain;

Described discrete fourier inversion converter unit 102, for described channel estimation in frequency domain is carried out discrete fourier inversion, obtains time domain channel and estimates;

Described snr computation unit 103 is for estimating according to described time domain channel the time domain signal to noise ratio calculating each adjacent area antenna port;

Described antenna port number judging unit 104 is for judging the quantity of adjacent area antenna port according to all adjacent area antenna port time domain signal to noise ratios.

Accordingly, please refer to Fig. 2, it is the schematic diagram that the present invention detects the method for adjacent area antenna port number.As shown in Figure 2, the invention provides a kind of method detecting adjacent area antenna port number, comprising:

S201: according to the Received signal strength at frequency domain RS place and the reference signal at local RS place, obtains channel estimation in frequency domain;

S202: described channel estimation in frequency domain is carried out discrete fourier inversion, obtains time domain channel and estimates;

S203: estimate the time domain signal to noise ratio calculating each adjacent area antenna port according to described time domain channel;

S204: the quantity judging adjacent area antenna port according to all adjacent area antenna port time domain signal to noise ratios.

[embodiment 1]

The antenna configuration received for two two of main flow typical in LTE, and for the OFDM(Orthogonal Frequency Division Multiplexing of a band RS, orthogonal frequency division multiplexi) symbol is described.Concrete grammar is as follows:

S201: according to the Received signal strength at frequency domain RS place with the reference signal at local RS place obtain channel estimation in frequency domain

In a preferred embodiment, LS(Least Square is adopted, least square) algorithm carries out channel estimation in frequency domain.

LS is estimated as follows shown in publicity: wherein, for the result of channel estimation in frequency domain; for the Received signal strength at frequency domain RS place; for the reference signal at local RS place, r is reception antenna numbering, and p is transmitting antenna port numbers, r ∈ { 0,1}, p ∈ { 0,1}.

Further, with be all vector, dimension is the RS number of individual antenna port in current sign, relevant with system bandwidth.Especially, in the present embodiment, supposing the system bandwidth is 20M, then the RS number of individual antenna port is 200,

That is: $\begin{array}{c}{\hat{H}}_{\mathrm{LS}}^{(r,p)}={[{\hat{h}}_{\mathrm{LS},0}^{(r,p)},{\hat{h}}_{\mathrm{LS},1}^{(r,p)}...,{\hat{h}}_{\mathrm{LS},199}^{(r,p)}]}^T\\ {\tilde{G}}^{(r,p)}={[{\tilde{g}}_0^{(r,p)},{\tilde{g}}_1^{(r,p)}...,{\tilde{g}}_{199}^{(r,p)}]}^T\\ {\tilde{R}}^{\left(p\right)}={[{\tilde{r}}_0^{\left(p\right)},{\tilde{r}}_1^{\left(p\right)}...,{\tilde{r}}_{199}^{\left(p\right)}]}^T\end{array}$

S202: by described channel estimation in frequency domain carry out discrete fourier inversion (IDFT conversion), obtain time domain channel and estimate

Due under broadband system, may there is stronger frequency selective fading in frequency domain, so from the more difficult antenna port number judging adjacent area of frequency domain.So, need, by IDFT, channel estimation in frequency domain is transformed to time domain, and then judge further.

In a preferred embodiment, the present embodiment passes through IFFT(Inverse Fast Fourier Transform, fast discrete Fourier inversion) realize IDFT fast.

Concrete, in this step, first channel estimation in frequency domain by the method for zero padding, channel estimation in frequency domain dimension mend into 2 integral number power; Preferably, in the present embodiment, dimension is mended to 256, obtaining channel estimating is ${\tilde{H}}_{\mathrm{LS}}^{(r,p)}={[{\tilde{h}}_{\mathrm{LS},0}^{(r,p)}{\tilde{h}}_{\mathrm{LS},1}^{(r,p)}...,{\tilde{h}}_{\mathrm{LS},255}^{(r,p)}]}^T$ Wherein,

${\tilde{h}}_{\mathrm{LS},i}^{(r,p)}=\left\{\begin{array}{cc}{\hat{h}}_{\mathrm{LS},i}^{(r,p)}& 0\≤i\≤199\\ 0& 200\≤i\≤255\end{array}\right.$

Then, to channel estimation in frequency domain do the IFFT conversion of 256, obtain time domain channel impulse response $H_{\mathrm{cir}}^{(r,p)}=[h_{\mathrm{cir},0}^{(r,p)},h_{\mathrm{cir},1}^{(r,p)},...,h_{\mathrm{cir},255}^{(r,p)}]:$ $H_{\mathrm{cir}}^{(r,p)}=\mathrm{IFFT}\left({\tilde{H}}_{\mathrm{LS}}^{(r,p)}\right);$

S203: estimate the time domain signal to noise ratio snr calculating each adjacent area antenna port according to described time domain channel ^(p);

Concrete, in this step, respond according to time domain channel impulse calculate signal power and the noise power of antenna port respectively.

First, calculate tap power for:

$\mathrm{po}{w}_{\mathrm{cir}}^{(r,p)}={[{\left|h_{\mathrm{cir},i=0}^{(r,p)}\right|}^2,{\left|h_{\mathrm{cir},i=1}^{(r,p)}\right|}^2,...,{\left|h_{\mathrm{cir},i=255}^{(r,p)}\right|}^2]}^T$

Especially, in the present embodiment, maximum tap power is set as signal power.Signal power calculate according to following formula:

$\mathrm{po}{e}_{\max }^{(r,p)}=\max \left\{\mathrm{po}{w}_{\mathrm{cir},i}^{(r,p)}\right\},i=0,...,255$

Then, the power averaging getting rear 128 taps, as noise power, thinks that the latter half that time domain channel impulse responds is all noise tap (selection of noise tap may affect by tap energies leakage, receive advance etc., needs to carry out relevant position adjustment).

Noise power calculate according to following formula:

${\mathrm{\Γ}}_{\mathrm{noise}}^{(r,p)}=\frac{1}{128}\·\underset{128}{\overset{255}{\mathrm{\Σ}}}\mathrm{po}{w}_{\mathrm{cir},i}^{(r,p)}$

Finally, the signal to noise ratio snr of p antenna port on r reception antenna is defined ^{(r, p)}, calculate according to following formula: $\mathrm{SN}{R}^{(r,p)}=\mathrm{po}{w}_{\max }^{(r,p)}/{\mathrm{\Γ}}_{\mathrm{noise}}^{(r,p)}$

Further, to two reception antennas of same antenna port signal to noise ratio be averaged:

SNR ^(p)＝(SNR ^(0,p)+SNR ^(1,p))/2

S204: the quantity judging adjacent area antenna port according to all adjacent area antennas port time domain signal to noise ratio snr (p).

Concrete, in this step, according to the antenna port time domain signal to noise ratio snr that step S203 obtains ^(p), judge according to following formula:

Wherein, α is the thresholding that antenna port number judges, experimental needs set, and in the present embodiment, select 10dB.

In this specification, each embodiment adopts the mode of going forward one by one to describe, and what each embodiment stressed is the difference with other embodiments, between each embodiment identical similar portion mutually see.Such as, the antenna received for four four is described, identical with the antenna that two two are received in detection method, but different on testing process.At this, concrete testing process of setting forth the antenna that four four are received, and detection method is not just repeating.

When four antenna ports detect, first calculate antenna port 2(or joint antenna port 3 and calculate) signal to noise ratio, compare judgement with antenna port 0.Suppose that antenna port 2 exists, be then judged to 4 antenna ports; Otherwise calculate the signal to noise ratio of antenna port 1 again, compare judgement with antenna port 0.Suppose that antenna port 1 exists, be then judged to 2 antenna ports, otherwise be judged to 1 antenna port.

Professional can also recognize further, in conjunction with unit and the algorithm steps of each example of embodiment disclosed herein description, can realize with electronic hardware, computer software or the combination of the two, in order to the interchangeability of hardware and software is clearly described, generally describe composition and the step of each example in the above description according to function.These functions perform with hardware or software mode actually, depend on application-specific and the design constraint of technical scheme.Professional and technical personnel can use distinct methods to realize described function to each specifically should being used for, but this realization should not thought and exceeds scope of the present invention.

Foregoing description is only the description to present pre-ferred embodiments, any restriction not to the scope of the invention, and any change that the those of ordinary skill in field of the present invention does according to above-mentioned disclosure, modification, all belong to the protection range of claims.

Claims (9)

1. detect a method for adjacent area antenna port number, it is characterized in that, comprising:

According to the Received signal strength at frequency domain RS place and the reference signal at local RS place, obtain channel estimation in frequency domain;

Described channel estimation in frequency domain is carried out discrete fourier inversion, obtains time domain channel and estimate;

The time domain signal to noise ratio calculating each adjacent area antenna port is estimated according to described time domain channel;

The quantity of adjacent area antenna port is judged according to all adjacent area antenna port time domain signal to noise ratios.

2. the method detecting adjacent area antenna port number as claimed in claim 1, it is characterized in that, in the step obtaining channel estimation in frequency domain, adopt the Received signal strength of least square method according to frequency domain reference signal RS place and the reference signal at local reference signal place, obtain channel estimation in frequency domain.

3. the method detecting adjacent area antenna port number as claimed in claim 1, it is characterized in that, described channel estimation in frequency domain is being carried out discrete fourier inversion, obtain in the step of time domain channel estimation, by after integral number power that the dimension of described channel estimation in frequency domain to be mended into by channel estimation in frequency domain 2 by the mode of zero padding, again channel estimation in frequency domain is done to the discrete fourier inversion of the integral number power of 2, estimate to obtain time domain channel.

4. the method detecting adjacent area antenna port number as claimed in claim 1, it is characterized in that, judging in the step of the quantity of adjacent area antenna port according to all adjacent area antenna port time domain signal to noise ratios, the antenna port number preset with one after adjacent area antenna port time domain signal to noise ratio is done computing judges that thresholding compares, thus judges the quantity of adjacent area antenna port.

5., as the method for the detection adjacent area antenna port number as described in arbitrary in claim 1-4, it is characterized in that, the quantity of described adjacent area antenna is four, is judging in the step of the quantity of adjacent area antenna port according to all adjacent area antenna port time domain signal to noise ratios,

First by the time domain signal to noise ratio of the time domain signal to noise ratio of antenna port 2 and antenna port 0 with compare judgement, if antenna port 2 exists, then judge that the quantity of adjacent area antenna port is 4;

Otherwise, then by the time domain signal to noise ratio of the time domain signal to noise ratio of antenna port 1 and antenna port 0 with compare judgement, if antenna port 1 exists, then judge that the quantity of adjacent area antenna port is 2; Otherwise then the quantity of adjacent area antenna port is 1.

6. detect a device for adjacent area antenna port number, it is characterized in that, comprising:

Channel estimation in frequency domain unit, for according to the Received signal strength at frequency domain RS place and the reference signal at local RS place, obtains channel estimation in frequency domain;

Discrete fourier inversion converter unit, for described channel estimation in frequency domain is carried out discrete fourier inversion, obtains time domain channel and estimates;

Snr computation unit, for estimating according to described time domain channel the time domain signal to noise ratio calculating each adjacent area antenna port;

Antenna port number judging unit, for judging the quantity of adjacent area antenna port according to all adjacent area antenna port time domain signal to noise ratios.

7. the device detecting adjacent area antenna port number as claimed in claim 6, it is characterized in that, in channel estimation in frequency domain unit, adopt the Received signal strength of least square method according to frequency domain reference signal RS place and the reference signal at local reference signal place, obtain channel estimation in frequency domain.

8. the device detecting adjacent area antenna port number as claimed in claim 6, it is characterized in that, in discrete fourier inversion converter unit, by after integral number power that the dimension of described channel estimation in frequency domain to be mended into by channel estimation in frequency domain 2 by the mode of zero padding, again channel estimation in frequency domain is done to the discrete fourier inversion of the integral number power of 2, estimate to obtain time domain channel.

9. the device detecting adjacent area antenna port number as claimed in claim 6, it is characterized in that, in antenna port number judging unit, the antenna port number preset with after adjacent area antenna port time domain signal to noise ratio is done computing judges that thresholding compares, thus judges the quantity of adjacent area antenna port.