CN104468434A - LTE-based descrambling device and method - Google Patents

Abstract

The invention discloses an LTE-based descrambling device and method and relates to mobile communication systems. The LTE-based descrambling device comprises a preprocessing unit, an RS position detection unit and a descrambling unit, wherein the preprocessing unit preprocesses symbol indexes of data to be descrambled, so that symbol indexes corresponding to the positions of a reference signal (RS) under an ordinary cyclic prefix (CP) and an extended CP are consistent; the RS position detection unit marks out the symbol indexes corresponding to the positions of the RS from the preprocessed data to be descrambled; the descrambling unit descrambles the marked data to be descrambled of the symbol indexes corresponding to the positions of the RS according to a local scrambling sequence c(n). The invention further discloses the LTE-based descrambling method. According to the technical scheme, the basic descrambling function is achieved, unification of different modes is achieved, the scramble generation time is shortened, the scramble generation speed is increased, and the LTE-based descrambling device and method have very high application value in an LTE wireless communication system.

Description

A kind of descrambler based on LTE and method

Technical field

The present invention relates in mobile communication system, particularly relate to a kind of descrambler based on LTE and method.

Background technology

LTE(Long Term Evolution) technology is the evolution of 3G technology, it adopts OFDM and MIMO as key technology, not only can reach the peak rate of the up 50M of descending 150M, and spectrum efficiency is higher, can according to the system bandwidth of business demand flexible configuration 1.4-20M.Not only like this, relative to 3G technology, it also also improves cell edge receptivity, improves cell capacity and reduce system delay.

But in LTE protocol, Normal CP is different with the mapping position of RS under Extended CP, and RS type is more.Existing conventional implementation, needs numerous Rule of judgment, and implementation procedure is comparatively loaded down with trivial details.

Summary of the invention

Technical problem to be solved by this invention is, provides a kind of descrambler based on LTE and method, to improve descrambling efficiency.

In order to solve the problems of the technologies described above, the invention discloses a kind of descrambler based on LTE, this device comprises:

Pretreatment unit, the notation index treating descrambling data carries out preliminary treatment, makes to treat that general cyclic prefix in descrambling data (CP) notation index corresponding with reference signal (RS) position under expansion CP is consistent;

RS position detection unit, marks notation index corresponding to RS position from pretreated treating descrambling data;

To what mark notation index corresponding to described RS position, Descrambling unit, treats that descrambling data carries out descrambling operation according to local scrambler sequence c (n).

Alternatively, above-mentioned descrambler also comprises:

Scrambler generation unit, adopts the be shifted mode of 2 bits of a clock cycle to produce two sequential values to form described local scrambler sequence simultaneously.

Alternatively, in above-mentioned descrambler, described scrambler generation unit produces local scrambler sequence c (n) according to following formula: $r_{{l,n}_s}\left(m\right)=\frac{1}{\sqrt{2}}(1-2\·c\left(2m\right))+j\frac{1}{\sqrt{2}}(1-2\·(2m+1)),m=\mathrm{0,1},...,{2N}_{\mathrm{RB}}^{\max ,\mathrm{DL}}-1$

Wherein, $\left\{\begin{array}{c}c\left(n\right)=(x_1(n+N_C)+x_2(n+N_C))\mathrm{mod}2\\ x_1(n+31)=(x_1(n+3)+x_1\left(n\right))\mathrm{mod}2\\ x_2(n+31)=(x_2(n+3)+x_2(n+2)+x_2(n+1)+x_2\left(n\right))\mathrm{mod}2\end{array}\right..$

Alternatively, in above-mentioned descrambler, N _c=1600 immobilize, x ₁n the initial value of () is x ₁(0)=1, x ₁(n)=0, n=1,2 ..., 30; x ₂n the initial value of () is wherein c _initcomputing formula as follows:

$c_{\mathrm{init}}=2^{10}\·(7\·(n_s+1)+l+1)\·(2\·N_{\mathrm{ID}}^{\mathrm{cell}}+1)+2\·N_{\mathrm{ID}}^{\mathrm{cell}}+N_{\mathrm{CP}}.$

Alternatively, in above-mentioned descrambler, described Descrambling unit, to described local scrambler sequence c (n) and mark notation index corresponding to described RS position treat that descrambling data does conjugation multiply operation to realize descrambling.

The invention also discloses a kind of de-scrambling method based on LTE, comprising:

The notation index first treating descrambling data carries out preliminary treatment, makes to treat that general cyclic prefix in descrambling data (CP) notation index corresponding with reference signal (RS) position under expansion CP is consistent;

Notation index corresponding to RS position is marked descrambling data again from pretreated treating;

Finally treat that descrambling data carries out descrambling operation according to local scrambler sequence c (n) to what mark notation index corresponding to described RS position.

Alternatively, said method also comprises:

Adopt the be shifted mode of 2 bits of a clock cycle to produce two sequential values to form described local scrambler sequence simultaneously.

Alternatively, in said method, produce local scrambler sequence c (n) according to following formula:

$r_{{l,n}_s}\left(m\right)=\frac{1}{\sqrt{2}}(1-2\·c\left(2m\right))+j\frac{1}{\sqrt{2}}(1-2\·(2m+1)),m=\mathrm{0,1},...,{2N}_{\mathrm{RB}}^{\max ,\mathrm{DL}}-1$

Wherein, $\left\{\begin{array}{c}c\left(n\right)=(x_1(n+N_C)+x_2(n+N_C))\mathrm{mod}2\\ x_1(n+31)=(x_1(n+3)+x_1\left(n\right))\mathrm{mod}2\\ x_2(n+31)=(x_2(n+3)+x_2(n+2)+x_2(n+1)+x_2\left(n\right))\mathrm{mod}2\end{array}\right..$

Alternatively, in said method, N _c=1600 immobilize, x ₁n the initial value of () is x ₁(0)=1, x ₁(n)=0, n=1,2 ..., 30; x ₂n the initial value of () is wherein c _initcomputing formula as follows:

$c_{\mathrm{init}}=2^{10}\·(7\·(n_s+1)+l+1)\·(2\·N_{\mathrm{ID}}^{\mathrm{cell}}+1)+2\·N_{\mathrm{ID}}^{\mathrm{cell}}+N_{\mathrm{CP}}.$

Alternatively, in said method, treat that descrambling data carries out descrambling operation and refers to according to local scrambler sequence c (n) to what mark notation index corresponding to described RS position:

To described local scrambler sequence c (n) and mark notation index corresponding to described RS position treat that descrambling data does conjugation multiply operation to realize descrambling.

Technical solution of the present invention provides a kind of scrambler generation device based on LTE protocol and method, not only achieve the basic function of descrambling, also achieve the unification of different mode, also shorten scrambler generation time, improve scrambler and produce speed, have very high using value at LTE wireless communication system.

Accompanying drawing explanation

Fig. 1 is the hardware implementing block diagram of descrambler of the present invention;

Fig. 2 is that x1 (n) sequence produces block diagram;

Fig. 3 is that x2 (n) sequence produces block diagram;

Fig. 4 is that Cell RS distributes schematic diagram;

Fig. 5 is that Vshift is identical with emission port, Cell RS position view when CP pattern is different;

Fig. 6 is that CP pattern is identical with emission port, Cell RS position view when Vshift is different;

When Fig. 7 is CP pattern difference, Cell RS position is unified detects schematic diagram;

When Fig. 8 is Vshift difference, Cell RS position is unified detects schematic diagram;

Fig. 9 is the hardware implementing schematic diagram of Descrambling unit in descrambler of the present invention.

Embodiment

For making the object, technical solutions and advantages of the present invention clearly understand, hereafter will be described in further detail technical solution of the present invention by reference to the accompanying drawings.It should be noted that, when not conflicting, the feature in the embodiment of the application and embodiment can combine arbitrarily mutually.

Embodiment 1

Present inventor sums up the mapping feature of RS under different mode, before detection scrambler position, carry out preliminary treatment to notation index, realizes the unification of RS position probing under Normal CP and Extended CP; In units of symbol, realize the unification of RS and Cell RS descrambling on Port4; The number of times of sequential shift is optimized, produces the parity bit of scrambler sequence simultaneously, so not only shorten scrambler generation time, and facilitate descrambling operation.

Based on above-mentioned thought, the present embodiment provides a kind of descrambler based on LTE, does conjugation multiply operation, at least comprise pretreatment unit, RS position detection unit and Descrambling unit by the RS data received and local c (n) sequence.

Pretreatment unit, the notation index treating descrambling data carries out preliminary treatment, makes to treat that general cyclic prefix in descrambling data (CP) notation index corresponding with reference signal (RS) position under expansion CP is consistent;

RS position detection unit, marks notation index corresponding to RS position from pretreated treating descrambling data;

To what mark notation index corresponding to described RS position, Descrambling unit, treats that descrambling data carries out descrambling operation according to local scrambler sequence c (n).

Preferably, on the basis of said apparatus, also comprise scrambler generation unit, now, based on the descrambler of LTE hardware structure as shown in Figure 1.

This scrambler generation unit: according to LTE protocol, adopts the mode of a clock cycle displacement 2bits to produce two sequential values to form local scrambler sequence simultaneously.

Below the concrete enforcement of processing unit each in Fig. 1 is described in further detail:

The hardware implementing of scrambler generation unit

According to agreement, c (n) sequence is by x ₁(n) sequence and x ₂n () mould 2 adds generation, formula is as follows:

$\left\{\begin{array}{c}c\left(n\right)=(x_1(n+N_C)+x_2(n+N_C))\mathrm{mod}2\\ x_1(n+31)=(x_1(n+3)+x_1\left(n\right))\mathrm{mod}2\\ x_2(n+31)=(x_2(n+3)+x_2(n+2)+x_2(n+1)+x_2\left(n\right))\mathrm{mod}2\end{array}\right.$

Wherein N _c=1600 immobilize, x ₁n the initial value of () is x ₁(0)=1, x ₁(n)=0, n=1,2 ..., 30; x ₂n the initial value of () is wherein c _initcomputing formula as follows:

$c_{\mathrm{init}}=2^{10}\·(7\·(n_s+1)+l+1)\·(2\·N_{\mathrm{ID}}^{\mathrm{cell}}+1)+2\·N_{\mathrm{ID}}^{\mathrm{cell}}+N_{\mathrm{CP}}$

Therefore, c (n) sequence be obtained, first must calculate x ₁(n) sequence and x ₂(n) sequence.

Due to x ₁n the initial value of () sequence is fixing, this just means that the sequential value at its 1600 place is also fixing, and we can, after reset signal arrives, be the sequential value at 1600 places to 31bits initialization of register like this.Work as x ₁n () index signal is started working after, first carry out calculating x according to formula ₁(30) value, and move to right 1, counter cumulative 1.Then carry out the concurrent operation that 2 groups of moulds 2 add below at every turn, and counter cumulative 2.Here the effect adopting 2 groups of moulds 2 to add is the reference signal used in reference signal generates is occur in pairs, produces the step of sequence after so just can adjusting.X ₁n the hardware implementing structure of () sequence as shown in Figure 2.

For x ₂(n) sequence, its initial value C _initwith No. slot, symbol number, community ID and CP pattern relevant, its initial value is not different in the same time, therefore x ₂n () sequence can only obtain C _initits initial value could be calculated afterwards.This programme adopts software to issue the mode (at least in advance subframe 800 clk) of the sequence initial value of each symbol, and hardware starts to carry out displacement and calculates after receiving sequence initial value, and obtain the sequential value at 1600 places, other calculates and x ₁n () sequence is the same, hardware implementing block diagram as shown in Figure 3.

According to x ₁(n) and x ₂n () sequence, we can obtain c (n) sequence.Due to x ₁(n) and x ₂n () sequence is all a clk displacement twice, export two sequential values, therefore c (n) sequence is also export two sequential values simultaneously simultaneously.Finally define according to the formula of CELL RS, we can obtain the local RS sequence produced.

$r_{{l,n}_s}\left(m\right)=\frac{1}{\sqrt{2}}(1-2\·c\left(2m\right))+j\frac{1}{\sqrt{2}}(1-2\·(2m+1)),m=\mathrm{0,1},...,{2N}_{\mathrm{RB}}^{\max ,\mathrm{DL}}-1$

It should be noted that the real scrambler needed is and current distribution RB number relevant, in the majority of cases, the sequence of 440 length is all used, and in other situation, we only use one section, the centre of sequence, so we are at initialization x ₁(n) and x ₂just must consider this problem when (n) sequence, calculate the position that we need sequence in advance.The scrambler service condition of 440 scrambler sequence as shown in Figure 4.

The hardware implementing of RS position detection unit

According to LTE protocol, the position of Cell RS and CP pattern, symbolic number, transmitting terminal slogan and vshift have relation.Even if emission port and Vshift are identical, if CP pattern is different, the position of RS is also different, as shown in Figure 5.Can find out in Fig. 5 left hand view, only just there is RS at symbol 0, state=0 and symbol 4, state=3, can find out only just there is RS at symbol 0, state=0 and symbol 3, state=3 in Fig. 5 right part of flg, namely RS is in the same sub-carrier of not same symbol.

Not only like this, even if emission port is identical, if Vshift is different, so the position of RS also can be different, as shown in Figure 6.Can find out in Fig. 6 left hand view, only just there is RS at symbol 0, state=0 and symbol 4, state=3, can find out only just there is RS at symbol 0, state=1 and symbol 4, state=4 in Fig. 6 right part of flg, namely RS is in the different sub carrier of same symbol.

In order to solve the problem that RS position changes with CP patterns of change, we are when hardware implementing, symbol count under Extended CP pattern is changed into 0,1,2,4,5,6 countings from original 0,1,2,3,4,5, as shown in Figure 7, RS appears on the position of symbol 0, state=0 and symbol 4, state=3, under so just achieving different CP pattern, the unified of RS position detects

In order to solve the problem that RS position changes with Vshift change, before hardware implementing, pretreatment unit is according to the difference of vshift, different initial conditions is given to state value, as shown in Figure 8, namely RS appears on the position of symbol 0, state=0 and symbol 4, state=3, and under so just achieving different vshift, the unified of RS position detects.

The hardware implementing of Descrambling unit

Descrambling module is actually a complex multiplication module, and only because multiplication factor is more special, namely RS signal value is then we can common factor extract, so RS signal can be equivalent to ± 1 ± j.Can find out, the complex multiplication now inputting data and RS signal only has addition and inversion operation, is finally multiplied by a real number factor again hardware implementing structure as shown in Figure 9.

Embodiment 2

The present embodiment provides a kind of de-scrambling method based on LTE, comprises following operation:

The notation index first treating descrambling data carries out preliminary treatment, makes to treat that general cyclic prefix in descrambling data (CP) notation index corresponding with reference signal (RS) position under expansion CP is consistent;

Notation index corresponding to RS position is marked descrambling data again from pretreated treating;

Finally treat that descrambling data carries out descrambling operation according to local scrambler sequence c (n) to what mark notation index corresponding to described RS position.

Based on the above method, also comprise the operation generating local mask code sequence, particularly, the be shifted mode of 2 bits of a clock cycle can be adopted to produce two sequential values to form described local scrambler sequence simultaneously.

Wherein, in the present embodiment, local scrambler sequence c (n) can be produced according to following formula:

$r_{{l,n}_s}\left(m\right)=\frac{1}{\sqrt{2}}(1-2\·c\left(2m\right))+j\frac{1}{\sqrt{2}}(1-2\·(2m+1)),m=\mathrm{0,1},...,{2N}_{\mathrm{RB}}^{\max ,\mathrm{DL}}-1$

Wherein, $\left\{\begin{array}{c}c\left(n\right)=(x_1(n+N_C)+x_2(n+N_C))\mathrm{mod}2\\ x_1(n+31)=(x_1(n+3)+x_1\left(n\right))\mathrm{mod}2\\ x_2(n+31)=(x_2(n+3)+x_2(n+2)+x_2(n+1)+x_2\left(n\right))\mathrm{mod}2\end{array}\right..$

It should be noted that, N _c=1600 immobilize, x ₁n the initial value of () is x ₁(0)=1, x ₁(n)=0, n=1,2 ..., 30; x ₂n the initial value of () is and c _initcomputing formula as follows:

$c_{\mathrm{init}}=2^{10}\·(7\·(n_s+1)+l+1)\·(2\·N_{\mathrm{ID}}^{\mathrm{cell}}+1)+2\·N_{\mathrm{ID}}^{\mathrm{cell}}+N_{\mathrm{CP}}.$

In actual mechanical process, treat that namely descrambling data carries out descrambling operation according to local scrambler sequence c (n) to what mark notation index corresponding to described RS position, to described local scrambler sequence c (n) and mark notation index corresponding to described RS position treat that descrambling data does conjugation multiply operation to realize descrambling.

The all or part of step that one of ordinary skill in the art will appreciate that in said method is carried out instruction related hardware by program and is completed, and described program can be stored in computer-readable recording medium, as read-only memory, disk or CD etc.Alternatively, all or part of step of above-described embodiment also can use one or more integrated circuit to realize.Correspondingly, each module/unit in above-described embodiment can adopt the form of hardware to realize, and the form of software function module also can be adopted to realize.The application is not restricted to the combination of the hardware and software of any particular form.

The above, be only preferred embodiments of the present invention, be not intended to limit protection scope of the present invention.Within the spirit and principles in the present invention all, any amendment made, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (10)

1. based on a descrambler of Long Term Evolution (LTE), it is characterized in that, this device comprises:

Pretreatment unit, the notation index treating descrambling data carries out preliminary treatment, makes to treat that general cyclic prefix in descrambling data (CP) notation index corresponding with reference signal (RS) position under expansion CP is consistent;

RS position detection unit, marks notation index corresponding to RS position from pretreated treating descrambling data;

To what mark notation index corresponding to described RS position, Descrambling unit, treats that descrambling data carries out descrambling operation according to local scrambler sequence c (n).

2. descrambler as claimed in claim 1, it is characterized in that, this device also comprises:

Scrambler generation unit, adopts the be shifted mode of 2 bits of a clock cycle to produce two sequential values to form described local scrambler sequence simultaneously.

3. device as claimed in claim 2, it is characterized in that, described scrambler generation unit produces local scrambler sequence c (n) according to following formula:

$r_{{l,n}_s}\left(m\right)=\frac{1}{\sqrt{2}}(1-2\·c\left(2m\right))+j\frac{1}{\sqrt{2}}(1-2\·(2m+1)),m=\mathrm{0,1},...,{2N}_{\mathrm{RB}}^{\max ,\mathrm{DL}}-1$

Wherein, $\left\{\begin{array}{c}c\left(n\right)=(x_1(n+N_C)+x_2(n+N_C))\mathrm{mod}2\\ x_1(n+31)=(x_1(n+3)+x_1\left(n\right))\mathrm{mod}2\\ x_2(n+31)=(x_2(n+3)+x_2(n+2)+x_2(n+1)+x_2\left(n\right))\mathrm{mod}2\end{array}\right..$

4. device as claimed in claim 3, is characterized in that,

N _c=1600 immobilize, x ₁n the initial value of () is x ₁(0)=1, x ₁(n)=0, n=1,2 ..., 30; x ₂n the initial value of () is wherein c _initcomputing formula as follows:

$c_{\mathrm{init}}=2^{10}\·(7\·(n_s+1)+l+1)\·(2\·N_{\mathrm{ID}}^{\mathrm{cell}}+1)+2\·N_{\mathrm{ID}}^{\mathrm{cell}}+N_{\mathrm{CP}}.$

5. the device as described in any one of Claims 1-4, is characterized in that,

Described Descrambling unit, to described local scrambler sequence c (n) and mark notation index corresponding to described RS position treat that descrambling data does conjugation multiply operation to realize descrambling.

6. based on a de-scrambling method of Long Term Evolution (LTE), it is characterized in that, the method comprises:

The notation index first treating descrambling data carries out preliminary treatment, makes to treat that general cyclic prefix in descrambling data (CP) notation index corresponding with reference signal (RS) position under expansion CP is consistent;

Notation index corresponding to RS position is marked descrambling data again from pretreated treating;

Finally treat that descrambling data carries out descrambling operation according to local scrambler sequence c (n) to what mark notation index corresponding to described RS position.

7. method as claimed in claim 6, it is characterized in that, the method also comprises:

Adopt the be shifted mode of 2 bits of a clock cycle to produce two sequential values to form described local scrambler sequence simultaneously.

8. method as claimed in claim 7, is characterized in that, produce local scrambler sequence c (n) according to following formula:

$r_{{l,n}_s}\left(m\right)=\frac{1}{\sqrt{2}}(1-2\·c\left(2m\right))+j\frac{1}{\sqrt{2}}(1-2\·(2m+1)),m=\mathrm{0,1},...,{2N}_{\mathrm{RB}}^{\max ,\mathrm{DL}}-1$

Wherein, $\left\{\begin{array}{c}c\left(n\right)=(x_1(n+N_C)+x_2(n+N_C))\mathrm{mod}2\\ x_1(n+31)=(x_1(n+3)+x_1\left(n\right))\mathrm{mod}2\\ x_2(n+31)=(x_2(n+3)+x_2(n+2)+x_2(n+1)+x_2\left(n\right))\mathrm{mod}2\end{array}\right..$

9. method as claimed in claim 8, is characterized in that,

N _c=1600 immobilize, x ₁n the initial value of () is x ₁(0)=1, x ₁(n)=0, n=1,2 ..., 30; x ₂n the initial value of () is wherein c _initcomputing formula as follows:

$c_{\mathrm{init}}=2^{10}\·(7\·(n_s+1)+l+1)\·(2\·N_{\mathrm{ID}}^{\mathrm{cell}}+1)+2\·N_{\mathrm{ID}}^{\mathrm{cell}}+N_{\mathrm{CP}}.$

10. the method as described in any one of claim 6 to 9, is characterized in that, treats that descrambling data carries out descrambling operation and refers to according to local scrambler sequence c (n) to what mark notation index corresponding to described RS position:

To described local scrambler sequence c (n) and mark notation index corresponding to described RS position treat that descrambling data does conjugation multiply operation to realize descrambling.