CN102905345B - Method for LTE (long term evolution) cell verification - Google Patents

Abstract

The invention discloses a method for LTE (long term evolution) cell verification. The method is characterized by including the steps of performing CHE (channel estimation) by odd subcarrier or even subcarrier of an SSS (secondary synchronization signal) according to result of SSS detection, smoothing, interpolating and extrapolating the channel estimation to acquire a CheSSS; performing CHE of frequency domain by a former RS (received signal) and a latter RS of the SSS, smoothing and interpolating the CHE, and averaging the CHE of the SSS and the CHE of the frequency domain to acquire CheRS; balancing a PSS (primary synchronization signal) by the CheSSS and performing normalization and multi-antenna superposition by corresponding RSSI (received signal strength indication). Measurement of a wrong cell and measurement of a correct cell are separated, and probability of leak detection is not increased as far as possible while probability of false alarm is reduced.

Description

A kind of LTE community verification method

Technical field

The invention belongs to mobile communication technology field, particularly a kind of LTE community verification method.

Background technology

The features such as LTE (LTE:Long Term Evolution, Long Term Evolution), as the main flow communication technology of future generation, has transmission rate high, and the availability of frequency spectrum is high, and receiver is simple.When UE rigidly connects community and maybe needs to switch, UE need to carry out Cell searching, to determine community own resident or that switch, in Cell searching, UE need to verify the community searching, to determine which is efficient cell, and which is invalid cell.Original verification method generally adopts PSS (PSS:Primary Synchronization Signal, master sync signal) correlation or SSS (SSS:Secondary Synchronization Signal, auxiliary synchronous signals) correlation is verified, the shortcoming of this algorithm is that the tolerance size that it adopts under different signal to noise ratios is different, and along with the not isometric size of channel fading is also different, therefore cannot select a unified threshold value that can be applied to various situations.

Summary of the invention

The object of this invention is to provide a kind of LTE community verification method, to solve the problem that tolerance that algorithm of the prior art selects cannot be unified with variation and the channel fading of signal to noise ratio.

Technical solution of the present invention is that a kind of LTE community verification method, comprises the following steps:

A1, the result detecting according to SSS, utilizes the odd subcarriers of SSS or even subcarriers to carry out channel estimating, and this channel estimating is carried out to level and smooth and interpolation and extrapolation, obtains the channel estimating CheSSS of SSS;

A2, utilize the previous RS of SSS and SSS after a RS carry out channel estimation in frequency domain, this channel estimating is carried out to level and smooth and interpolation, and both channel estimating is averaged to the channel estimating CheRS that obtains RS;

A3, utilizes CheSSS PSS is carried out to equilibrium and utilize corresponding RSSI to be normalized and carry out the stack of many antennas;

A4, utilizes CheSSS the previous RS of SSS is carried out to equilibrium and utilize corresponding RSSI to be normalized and carry out the stack of many antennas;

A5, utilize CheSSS to SSS after a RS carry out equilibrium and utilize corresponding RSSI to be normalized and carry out the stack of many antennas;

A6, utilizes CheRS SSS is carried out to equilibrium and utilize corresponding RSSI to be normalized and carry out the stack of many antennas;

A7, the sequence summation after PSS equilibrium and the stack of many antennas, tries to achieve the tolerance MetricPSS of PSS;

A8, the sequence summation after SSS equilibrium and the stack of many antennas, tries to achieve the tolerance MetricSSS of SSS;

A9, the sequence summation being positioned at after the previous RS equilibrium of SSS and the stack of many antennas, tries to achieve the tolerance MetricRS of first RS ₁;

A10, the sequence summation being positioned at after SSS after the balanced and many antennas stacks of RS, tries to achieve the tolerance MetricRS of second RS ₂;

A11, by MetricPSS, MetricSSS, MetricRS ₁and MetricRS ₂addition obtains final Metric;

A12, according to | Metric| ²descending sequence is carried out in all communities, refer to the mould square of asking plural;

A13, selects | Metric| ²be greater than a predefined threshold value S ₁community, all the other communities are all considered as invalid cell;

A14, traversal step A13 provide according to | Metric| ²descending efficient cell list of sorting, in table the value of the ID mould 3 of i community with show in the value of 1st～i-1Ge community ID mould 3 identical, to i community | MetricSSS+MetricRS ₁+ MetricRS ₂| ²with a predefined threshold value S ₂compare, when it is greater than S ₂think that community is effective, otherwise think invalid;

A15, traversal step A14 provide according to | Metric| ²descending efficient cell list of sorting, in table the value of the ID mould 6 of i community with show in the value of 1st～i-1Ge community ID mould 6 identical, to i community | MetricSSS| ²with a predefined threshold value S ₃compare, when | MetricSSS| ²be greater than S ₃think that community is effective, otherwise think invalid;

A16, traversal step A15 provide according to | Metric| ²descending efficient cell list of sorting, i community in table | Metric| ²with first community in table | Metric| ²ratio be less than a predefined threshold value S ₄, think that this community is effective, otherwise think invalid, thereby draw final efficient cell list.

The invention enables the tolerance of wrong cell to separate with the tolerance of correct community, when reducing false alarm probability, do not improve undetected probability as far as possible.

Accompanying drawing explanation

Fig. 1 is two RS and the distribution in frame of two synchronizing symbols under TDD and fdd mode.

Fig. 2 is the structure chart that calculates SSS channel estimating in technical solution of the present invention.

Embodiment

As shown in Figure 2, first SSS is divided into odd even two parts according to the sequence number of subcarrier, sequence of parity is carried out respectively to channel estimating, the method for channel estimating is as follows:

$\left\{\begin{array}{c}h\left(2k\right)=r_{\mathrm{SSS}}\left(2k\right)S_{\mathrm{SSS}}\left(2k\right)\\ h(2k+1)=r_{\mathrm{SSS}}(2k+1)S_{\mathrm{SSS}}(2k+1)\end{array}\right.k=\mathrm{0,1},\·\·\·,30---\left(1\right)$

In formula, r _sSS(k) be to receive SSS frequency domain sequence, S _sSSbe local SSS frequency domain sequence, odd-even channel is estimated to carry out respectively level and smooth de-noising, the method that smoothly can adopt adjacent some subcarriers to be averaged is carried out, and the odd-even channel after level and smooth estimates to be respectively h _mA(2k) and h _mA(2k+1).Ask both energy to be

$\left\{\begin{array}{c}{P}_{\mathrm{even}}=\underset{k=0}{\overset{30}{\mathrm{\Σ}}}{\left|h_{\mathrm{MA}}\left(2k\right)\right|}^2\\ P_{\mathrm{odd}}=\underset{k=0}{\overset{30}{\mathrm{\Σ}}}{\left|h_{\mathrm{MA}}(2k+1)\right|}^2\end{array}\right.---\left(2\right)$

If even number energy P _even< P _oddselect h _mA(2k) carry out next step operation, otherwise select h _mA(2k+1) carry out next step operation.

The odd-even channel of selecting according to previous step estimates to carry out interpolation, if what select is that even-numbered channels is estimated, utilize the channel estimating interpolation in even subcarriers to go out the channel estimation value in odd subcarriers, if what select is that odd-numbered channels is estimated, utilize the channel estimating interpolation in odd subcarriers to go out the channel estimation value in even subcarriers.Interpolation can adopt first-order linear interpolation also can adopt other interpolation methods.Because SSS frequency domain sequence only has 62 available points, the channel estimating of 62 points need to be extrapolated to 72 subcarriers and get on, in the time of extrapolation, also can utilize first-order linear extrapolation or other Extrapolation method.So just obtain the channel estimating CheSSS of 72 points.

Secondly, take out the previous RS frequency domain symbol of SSS, take out RS subcarrier, by the conjugation of subcarrier and local RS sequence, multiply each other and have

$h_{\mathrm{RS}}\left(k\right)=r_{\mathrm{RS}}\left(k\right)S_{\mathrm{RS}}^{*}\left(k\right)---\left(3\right)$

In formula, r _rS(k) be to receive RS subcarrier, S _rS(k) be local RS sequence. to ask conjugation.Then to h _rS(k) carry out smoothly, the channel estimating interpolation after utilization is level and smooth the channel estimating on extrapolated 72 subcarriers, obtain CheRS ₁.It is CheRS that same method can obtain the channel estimating of a RS frequency domain symbol after SSS ₂.The channel estimating of the channel estimating of the previous RS of SSS and a rear RS is on average obtained to the channel estimating CheRS of final RS.

Obtaining just can calculating various tolerance after channel estimating, is first to have according to the tolerance MetricPSS of CheSSS calculating PSS

$\mathrm{MetricPSS}=\underset{\mathrm{rx}\_\mathrm{Ant}\_\mathrm{num}}{\mathrm{\&Sigma;}}\frac{\underset{k}{\mathrm{\&Sigma;}}{r}_{\mathrm{PSS}}\left(k\right)S_{\mathrm{PSS}}^{*}\left(k\right)\mathrm{CheSS}{S}^{*}\left(k\right)}{\underset{k}{\mathrm{\&Sigma;}}{\left|r_{\mathrm{PSS}}\left(k\right)\right|}^2}---\left(4\right)$

R in formula _pSS(k) be to receive PSS frequency domain sequence, S _pSS(k) be the local sequence of PSS, rx_Ant_num is reception antenna number.

Then according to CheRS, SSS is carried out to equilibrium and obtain the tolerance MetricSSS of SSS

$\mathrm{MetricSSS}=\underset{\mathrm{rx}\_\mathrm{Ant}\_\mathrm{num}}{\mathrm{\&Sigma;}}\frac{\underset{k}{\mathrm{\&Sigma;}}{r}_{\mathrm{SSS}}\left(k\right)S_{\mathrm{SSS}}^{*}\left(k\right)\mathrm{CheR}{S}^{*}\left(k\right)}{\underset{k}{\mathrm{\&Sigma;}}{\left|r_{\mathrm{SSS}}\left(k\right)\right|}^2}---\left(5\right)$

And by identical method, calculate the tolerance of RS

$\mathrm{MetricR}{S}_1=\underset{\mathrm{rx}\_\mathrm{Ant}\_\mathrm{num}}{\mathrm{\&Sigma;}}\frac{\underset{k}{\mathrm{\&Sigma;}}{r}_{\mathrm{RS}1}\left(k\right)S_{\mathrm{RS}1}^{*}\left(k\right)\mathrm{CheSS}{S}^{*}\left(k\right)}{\underset{k}{\mathrm{\&Sigma;}}{\left|r_{\mathrm{RS}1}\left(k\right)\right|}^2}---\left(6\right)$

$\mathrm{MetricR}{S}_2=\underset{\mathrm{rx}\_\mathrm{Ant}\_\mathrm{num}}{\mathrm{\&Sigma;}}\frac{\underset{k}{\mathrm{\&Sigma;}}{r}_{\mathrm{RS}2}\left(k\right)S_{\mathrm{RS}2}^{*}\left(k\right)\mathrm{CheSS}{S}^{*}\left(k\right)}{\underset{k}{\mathrm{\&Sigma;}}{\left|r_{\mathrm{RS}2}\left(k\right)\right|}^2}---\left(7\right)$

After being added, these four tolerance obtain final Metric

Metric＝MetricPSS+MetricSSS+MetricRS ₁+MetricRS ₂ (8)

According to | Metric| ²original cell list is sorted according to descending, obtain cell list L1.

Traversal L1, selects | Metric| ²be greater than a predefined threshold value S ₁community, all the other communities are all considered as invalid cell, obtain cell list L2.

Traversal L2, in table the value of the ID mould 3 of i community with show in the value of 1st～i-1Ge community ID mould 3 identical, to i community | MetricSSS+MetricRS ₁+ MetricRS ₂| ²with a predefined threshold value S ₂compare, when it is greater than S ₂think that community is effective, otherwise think invalid, obtain cell list L3.

Traversal L3, in table the value of the ID mould 6 of i community with show in the value of 1st～i-1Ge community ID mould 6 identical, to i community | MetricSSS| ²with a predefined threshold value S ₃compare, when | MetricSSS| ²be greater than S ₃think that community is effective, otherwise think invalid, obtain cell list L4.

Traversal L4, i community in table | Metric| ²with first community in table | Metric| ²ratio be greater than a predefined threshold value S ₄, think that this community is effective, otherwise think invalid, thereby draw final efficient cell list.

Claims (1)

1. Yi Zhong LTE community verification method, is characterized in that, comprises the following steps:

A1, the result detecting according to auxiliary synchronous signals (SSS), utilize odd subcarriers and the even subcarriers of this auxiliary synchronous signals (SSS) to carry out channel estimating, this channel estimating is carried out to level and smooth and interpolation and extrapolation, obtain the channel estimating CheSSS of this auxiliary synchronous signals (SSS);

A2, utilize the previous reference signal of this auxiliary synchronous signals (SSS) (RS) and the rear reference signal of this auxiliary synchronous signals (SSS) (RS) to carry out channel estimation in frequency domain, this channel estimating is carried out to level and smooth and interpolation, and both channel estimating are averaged to the channel estimating CheRS that obtains reference signal (RS);

A3, utilizes CheSSS to carry out equilibrium to master sync signal (PSS) and utilizes the signal strength signal intensity of corresponding reception indicate (RSSI) to be normalized and carry out the stack of many antennas;

A4, utilizes CheSSS to carry out equilibrium to the previous reference signal of this auxiliary synchronous signals (SSS) (RS) and utilizes the signal strength signal intensity of corresponding reception indicate (RSSI) to be normalized and carry out the stack of many antennas;

A5, utilizes CheSSS to carry out equilibrium to the rear reference signal of this auxiliary synchronous signals (SSS) (RS) and utilizes the signal strength signal intensity of corresponding reception indicate (RSSI) to be normalized and carry out the stack of many antennas;

A6, utilizes CheRS to carry out equilibrium to this auxiliary synchronous signals (SSS) and utilizes the signal strength signal intensity of corresponding reception indicate (RSSI) to be normalized and carry out the stack of many antennas;

A7, the sequence summation after this master sync signal (PSS) equilibrium and the stack of many antennas, tries to achieve the tolerance MetricPSS of this master sync signal (PSS);

A8, the sequence summation after this auxiliary synchronous signals (SSS) equilibrium and the stack of many antennas, tries to achieve the tolerance MetricSSS of this auxiliary synchronous signals (SSS);

A9, the sequence summation being positioned at after the previous reference signal of this auxiliary synchronous signals (SSS) (RS) equilibrium and the stack of many antennas, tries to achieve the tolerance MetricRS of first reference signal (RS) ₁;

A10, the sequence summation being positioned at after the rear reference signal of this auxiliary synchronous signals (SSS) (RS) equilibrium and the stack of many antennas, tries to achieve the tolerance MetricRS of second reference signal (RS) ₂;

A11, by MetricPSS, MetricSSS, MetricRS ₁and MetricRS ₂addition obtains final Metric;

A12, according to | Metric| ²descending sequence is carried out in all communities, | Metric| ²refer to the mould square of asking plural;

A13, selects | Metric| ²be greater than a predefined threshold value S ₁community, all the other communities are all considered as invalid cell;

A14, traversal step A13 provide according to | Metric| ²the efficient cell list of descending sequence, in table the value of the ID mould 3 of i community with show in the value of 1st～i-1Ge community ID mould 3 identical, to i community | MetricSSS+MetricRS ₁+ MetricRS ₂| ²with a predefined threshold value S ₂compare, when it is greater than S ₂think that community is effective, otherwise think invalid;

A15, traversal step A14 provide according to | Metric| ²the efficient cell list of descending sequence, in table the value of the ID mould 6 of i community with show in the value of 1st～i-1Ge community ID mould 6 identical, to i community | MetricSSS| ²with a predefined threshold value S ₃compare, when | MetricSSS| ²be greater than S ₃think that community is effective, otherwise think invalid;

A16, traversal step A15 provide according to | Metric| ²the efficient cell list of descending sequence, i community in table | Metric| ²with first community in table | Metric| ²ratio be less than a predefined threshold value S ₄, think that this community is effective, otherwise think invalid, thereby draw final efficient cell list.