CN101997568A - Method and device for scrambling positioning reference signals - Google Patents

Abstract

The embodiment of the invention discloses a method and a device for scrambling positioning reference signals and belongs to the field of communication. The method comprises the following steps of: acquiring a time slot serial number ns, an orthogonal frequency division multiplexing (OFDM) symbol serial number l, a cell identity cyclic prefix (CP) length identity network control protocol (NCP); acquiring frequency shift information vshift of the positioning reference signals (PRSs); acquiring a scrambling sequence according to the acquired ns, l, NCP and vshift; and scrambling the PRSs according to the scrambling sequence. The device comprises an information acquisition module, a scrambling sequence acquisition module and a scrambling module. In the technical scheme provided by the embodiment of the invention, the scrambling sequence of the generated PRSs has higher randomness by using the frequency shift information as an element of the scrambling sequence, the mutual interference among the PRSs received by user equipment (UE) at the same time is reduced, and the positioning precision of the UE is improved. A register of a Gold sequence is fully used, and the waste of resources is reduced.

Description

A kind of method and device that location reference signals is carried out scrambling

Technical field

The present invention relates to the communications field, particularly a kind of method and device that location reference signals is carried out scrambling.

Background technology

Along with development of Communication Technique, in LTE (Long Term Evolution, the Long Term Evolution) system application of portable terminal location technology more and more widely, for example, SOS telephone service, specific tracking service etc.The portable terminal location technology is the technology that portable terminal is accurately measured in residing geographical position sometime, by in the base station to UE (UserEquipment, subscriber equipment) carries PRS (Positioning Reference Signal in the subframe that issues, location reference signals) realizes the location (wherein, the subframe of carrying PRS is called positioning sub-frame) of portable terminal.For the accurate location of UE, UE need detect the PRS that a plurality of base stations issue, and is which base station issues in order to make UE can distinguish the PRS that receives, the frequency shift (FS) position of the PRS that adopt in the positioning sub-frame that issues separately each base station must be different.But because that the employing of LTE system is OFDMA (Orthogonal Frequency Division Multiple Access, OFDM) access way, PRS has only 6 kinds of different frequency location modes of deflection under this access way, and the number of base stations that needs in the LTE system to support is 504, therefore for UE, at synchronization, the frequency shift (FS) position of the PRS of two base stations of receiving may be identical, this just makes PRS interfere with each other easily, the collision incident takes place in the PRS that causes UE to receive, thus the accurate location that also just can not realize UE.

In order to reduce collision probability from the PRS of different base station, reduce the collision incident, the PRS randomization that the base station is issued usually, is handled the randomization that realizes PRS by the PRS in the time slot is carried out scrambling.In the LTE system, utilize scramble sequence to realize that PRS is carried out scrambling to be handled, wherein, scramble sequence employing length is 31 Gold sequence (being that the number of registers is 31).Referring to Fig. 1, the Gold sequence is by producing through XOR after the initialization of two m sequences, and x among Fig. 1 (i) is the initialization value of first m sequence of input, and first m sequence adopts set form initialization (x (0)=1 (highest order), x (1)=...=x (30)=0), c _InitBe the initialization value of second m sequence of input,, therefore can pass through to change c because x (i) fixes _InitJust can generate different Gold sequences, c in the prior art _InitBe that scrambling formula by CRS (Cell-Specific Reference Signal, cell special reference) obtains, referring to as follows:

$c_{\mathrm{init}}=2^{10}\·(7\·(n_{\text{s}}+1)+l+1)\·(2\·N_{\mathrm{ID}}^{\mathrm{cell}}+1)+2\·N_{\mathrm{ID}}^{\mathrm{cell}}+N_{\mathrm{CP}}\·\·\·\left(1\right)$

In the formula (1), c _InitBe the initialization value of second m sequence generating the Gold sequence, n _sFor time slot sequence number, l be OFDM symbol sequence number,

Be base station IDs, N _CPBe CP (Cyclic Prefix, Cyclic Prefix) length mark.

After above-mentioned prior art was analyzed, the inventor found:

The c that through type (1) obtains _Init≤ 2 ²⁸-1, i.e. c _InitScope be 0～(2 ²⁸-1), therefore the initialization value of second m sequence of the generation Gold sequence of the scrambling formula (1) of CRS acquisition is limited in scope as can be seen, so also the initialization value of the feasible Gold sequence that produces is limited, and then make that the randomness of PRS is limited, collision probability when therefore the PRS of different districts arrives UE is still bigger, the problem that interferes with each other between the PRS still compares serious, thereby also just influences the accurate of location; And, from c _Init≤ 2 ²⁸As can be seen, utilize the scrambling formula of CRS to carry out 28 registers that the Gold sequence has only been used in scrambling in-1, the wasting of resources is more serious.

Summary of the invention

In order to reduce interfering with each other between the PRS that different base station issues, improve the precision that UE is positioned, reduce the wasting of resources, the embodiment of the invention provides a kind of method that location reference signals is carried out scrambling, and described method comprises:

Obtain time slot sequence number n _s, orthogonal frequency division multiplex OFDM symbol sequence number l, cell ID

Cyclic prefix CP length mark N _CPObtain the frequency offset information v of location reference signals PRS _ShiftAccording to the described n that obtains _s, l,

N _CPAnd v _ShiftGenerate scramble sequence; According to described scramble sequence described PRS is carried out scrambling.

The embodiment of the invention provides a kind of device that location reference signals is carried out scrambling, and described device comprises: information acquisition module, scramble sequence generation module and scrambling module; Described information acquisition module is used to obtain time slot sequence number n _s, orthogonal frequency division multiplex OFDM symbol sequence number l, cell ID

Cyclic prefix CP length mark N _CPAlso be used to obtain the frequency offset information v of location reference signals PRS _ShiftDescribed scramble sequence generation module is used for the n that obtains according to described information acquisition module _s, l,

N _CPAnd v _ShiftGenerate scramble sequence; Described scrambling module is used for according to the scramble sequence that described scramble sequence generation module generates described PRS being carried out scrambling.

The beneficial effect of the technical scheme that the embodiment of the invention provides is: by frequency offset information being used as the element of scramble sequence, the scramble sequence of the feasible PRS that generates has had bigger randomness, reduce UE interfering with each other between the PRS that synchronization is received, improved the precision that UE is positioned; And made full use of the register of Gold sequence, reduced the wasting of resources.

Description of drawings

Fig. 1 is the schematic diagram of the generation Gold sequence that provides of prior art.

Fig. 2 be the normal sub-frames that provides of the embodiment of the invention 1 under the situation of different antennae configuration and CP length, the schematic diagram of PRS.

Fig. 3 be the embodiment of the invention 1 provide location reference signals is carried out the flow chart of the method for scrambling.

Fig. 4 is the schematic representation of apparatus that location reference signals is carried out scrambling that the embodiment of the invention 2 provides.

Embodiment

For making the purpose, technical solutions and advantages of the present invention clearer, embodiment of the present invention is described further in detail below in conjunction with accompanying drawing.

Referring to Fig. 2, for normal sub-frames under the situation of different antennae configuration and CP (Cyclic Prefix, Cyclic Prefix) length, the schematic diagram of PRS, wherein, the little square frame of black is represented PRS, R0 and dapple square frame are represented is CRS under the different antennae.Owing to adopt the access way of OFDMA in the LTE system, the information-bearing that is user in the sub-district is on mutually orthogonal different carrier, time, a last radio frames length was 10ms, comprise 10 subframes, each subframe is 1ms, each subframe comprises 2 time slots, when the CP of subframe is normal CP, each time slot comprises 7 OFDM symbols, when the CP of subframe was expansion CP, each time slot comprised 6 OFDM symbols, on the frequency is to be made of a plurality of subcarriers, a subcarrier under OFDM symbol is called a RE (Resource Element, Resource Unit), 12 subcarriers and a time slot constitute a RB (Resource Block, Resource Block), each subframe comprises two RB, and promptly the RB piece is right.As can be seen from Figure 2, although the distance in each OFDM symbol between the PRS is the same, but the position difference that on frequency domain, takies, PRS has 6 kinds of different frequency location skews in the RE position of a RB piece centering correspondence, and the number of cells that needs in the LTE system to support is 504, therefore at synchronization, the frequency shift (FS) position of two sub-districts may be identical, cause the collision incident may take place, therefore by PRS is carried out scrambling handle make PRS realize randomization after, collision probability when the PRS of different districts arrives UE has also just reduced, thereby also just can realize accurate localization.

For interfering with each other between the PRS that can reduce different districts greatly, the precision that raising positions UE, the embodiment of the invention provides a kind of method for scrambling that location reference signals is carried out, for convenience of explanation, scramble sequence is that example is carried out with the Gold sequence in the embodiment of the invention, referring to Fig. 3, this method comprises:

101: obtain time slot sequence number n _s, OFDM symbol sequence number l, cell ID

CP length mark N _CP, and obtain the frequency offset information v of PRS _Shift

Wherein, as previously mentioned, n _s, l,

And N _CPBe the information that agreement is reserved in the LTE system, repeat no more herein.

Wherein, because therefore each sub-district, needs the base station when UE issues current positioning sub-frame in the frequency offset information difference that each positioning sub-frame adopts, get access to the frequency offset information that this positioning sub-frame adopts, promptly need to obtain the frequency offset information of the current PRS that issues.Wherein, frequency offset information v _ShiftObtain manner can for:

Wherein,

Perhaps be:

$v_{\mathrm{shift}}=N_{\mathrm{Cell}}^{\mathrm{ID}}\mathrm{mod}6$

Perhaps be:

$v_{\mathrm{shift}}\left(i\right)=(v_{\mathrm{shift}}(i-1)+\left(\underset{k=i\·10+1}{\overset{i\·10+9}{\mathrm{\Σ}}}c\left(k\right)2^{k-(i\·10+1)}\right)\mathrm{mod}{N}_{\mathrm{sb}}+1){\mathrm{mod}N}_{\mathrm{sb}};$

Wherein, N _Sb=6,

v _shift(-1)＝0，

Perhaps be:

Wherein,

Perhaps be:

$v_{\mathrm{shift}}\left(i\right)=(v_{\mathrm{shift}}(i-1)+\left(\underset{k=i\·10+1}{\overset{i\·10+9}{\mathrm{\Σ}}}c\left(k\right)2^{k-(i\·10+1)}\right)\mathrm{mod}5+1)\mathrm{mod}6,$

Wherein, $v_{\mathrm{shift}}(-1)=N_{\mathrm{Cell}}^{\mathrm{ID}}$

Perhaps be:

$v_{\mathrm{shift}}\left(i\right)=((v_{\mathrm{shift}}(i-1)+\left(\underset{k=i\·10+1}{\overset{i\·10+9}{\mathrm{\Σ}}}c\left(k\right)2^{k-(i\·10+1)}\right)\mathrm{mod}5+1)\mathrm{mod}6+N_{\mathrm{Cell}}^{\mathrm{ID}})\mathrm{mod}6,$

Wherein, v _Shift(1)=0

Perhaps be:

$v_{\mathrm{shift}}\left(i\right)=(w\left(i\right)+N_{\mathrm{Cell}}^{\mathrm{ID}})\mathrm{mod}6;$

Wherein, $w\left(i\right)=(w(i-1)+\left(\underset{k=i\·10+1}{\overset{i\·10+9}{\mathrm{\Σ}}}c\left(k\right)2^{k-(i\·10+1)}\right)\mathrm{mod}5+1)\mathrm{mod}6,$

w(-1)＝0

Obtaining frequency offset information v _ShiftThe various forms of expression in, c () is the Gold sequence, and the initialization value of this c () is

T, j and k represent the variable of calculation times, and mod represents to get surplus, and i represents subframe numbers, 6 kinds of frequency location modes of deflection of 6 expressions.

Those skilled in the art can know that frequency offset information can as above several modes acquire, and also can adopt other mode to obtain, and the embodiment of the invention is not done any restriction to this.

As previously mentioned, because the frequency shift (FS) pattern of PRS has and has only 6 kinds in the LTE system, and LTE number of base stations that system supports is 504, therefore for UE, at synchronization, the frequency shift (FS) position of the PRS of two base stations of receiving may be identical, and this just makes PRS interfere with each other easily, collision incident, the accurate location that just can not realize UE take place in the PRS that causes UE to receive.In order effectively to avoid the problems referred to above, need carry out scrambling to PRS handles, the content that the method that the embodiment of the invention provides is obtained based on above-mentioned steps 101 and step 102, obtain the Gold sequence, according to this Gold sequence PRS is carried out scrambling, increasing reduces PRS further the collision incident takes place the degree of randomization of the PRS that issues.See for details as follows:

102: according to the time slot sequence number n that obtains _s, OFDM symbol sequence number l, cell ID

CP length mark N _CP, and the frequency offset information of PRS, generate scramble sequence;

103: PRS is carried out scrambling according to the scramble sequence that generates.

In the embodiment of the invention, according to the n that obtains _s, l,

N _CPAnd v _ShiftGenerate scramble sequence, comprising: the initialization value that obtains first m sequence;

According to the n that obtains _s, l,

N _CPAnd v _Shift, obtain the initialization value c of second m sequence _Init

Generate scramble sequence according to the initialization value of first m sequence and the initialization value of second m sequence.

Wherein, as shown in Figure 1, the initialization value that generates first m sequence of Gold sequence is fixed, so generate the Gold sequence that the initialization value of second m sequence of Gold sequence directly affects generation.

Therefore,, according to the n that obtains _s, l,

N _CPAnd v _Shift, obtain the initialization value c of second m sequence _Init, specific implementation can be as follows:

1)、 $c_{\mathrm{init}}=2^{10}\·(7\·(n_{\text{s}}+1)+l+1)\·((v_{\mathrm{shift}}+1)\·2\·N_{\mathrm{ID}}^{\mathrm{cell}}+1)+2\·N_{\mathrm{ID}}^{\mathrm{cell}}+N_{\mathrm{CP}}\·\·\·\left(2\right)$

In the formula (2), c _InitBe the initialization value of second m sequence generating the Gold sequence, n _sFor time slot sequence number, l be OFDM symbol sequence number, Be cell ID, N _CPBe CP length mark, v _ShiftBe frequency offset information.

Perhaps,

2)、 $c_{\mathrm{init}}=2^{10}\·(7\·(n_{\text{s}}+1)+l+1)\·(v_{\mathrm{shift}}+1)\·(2\·N_{\mathrm{ID}}^{\mathrm{cell}}+1)+2\·N_{\mathrm{ID}}^{\mathrm{cell}}+N_{\mathrm{CP}}\·\·\·\left(3\right)$

In the formula (3), c _InitBe the initialization value of second m sequence generating the Gold sequence, n _sFor time slot sequence number, l be OFDM symbol sequence number,

Be cell ID, N _CPBe CP length mark, v _ShiftBe frequency offset information.

Need to prove that the embodiment of the invention has only been enumerated two kinds of formula (2) and (3) that obtain the initialization value of second m sequence, but be not limited to this two formula (2) and (3).

To sum up, by with the element of frequency offset information, thereby strengthen degree of randomization, further, reduce PRS the collision incident takes place the PRS that issues as the scramble sequence of PRS being carried out scrambling (present embodiment is the Gold sequence).

The CRS scrambling formula of prior art In, because n _sSmaller or equal to 19, l is smaller or equal to 6,

Smaller or equal to 503, N _CPSmaller or equal to 1, can obtain c _Init≤ 2 ²⁸-1, the initialization value scope of second m sequence that promptly generates the Gold sequence is 0～(2 ²⁸-1), and in the formula (2) and (3) of frequency offset information that the embodiment of the invention provides, because n as the scramble sequence element that PRS is carried out scrambling with PRS _sSmaller or equal to 19, l is smaller or equal to 6,

Smaller or equal to 503, N _CPSmaller or equal to 1, v _ShiftSmaller or equal to 5, can obtain c _Init≤ 2 ³⁰-1, the initialization value scope of second m sequence that promptly generates the Gold sequence is 0～(2 ³⁰-1), can obviously find out, the initialization value scope that generates second m sequence of Gold sequence has increased greatly with respect to prior art, because the initialization value of Gold sequence and second m sequence has confidential relation, after the initialization value scope of second m sequence increases, the scope of the Gold sequence that generates also just increases greatly, after utilizing this Gold sequence that PRS is carried out scrambling, also just increased the randomness of PRS, reduce the collision probability of the PRS that UE receives at synchronization, thereby increased the accuracy of UE location.And c from the prior art acquisition _Init≤ 2 ²⁸As can be seen, in 31 registers that the Gold sequence provides, only used 28 registers in-1, so the scrambling scheme of prior art do not make full use of Gold sequence 31 bit registers, and the c that calculates from the scrambling apparatus that the embodiment of the invention provides _Init≤ 2 ³⁰Find out in-1 that the scrambling apparatus that the embodiment of the invention provides has used 30 registers,, made full use of the register of Gold sequence, reduced the wasting of resources with respect to prior art.

By emulation the scheme that prior art and the embodiment of the invention provide is contrasted in the present embodiment, simulated conditions is that system bandwidth is 10M, PRS adopts the frequency shift (FS) pattern of normal sub-frames when normal CP and the emission of two antennas, sliding window is 4 OFDM symbols (sliding window is the OFDM symbol of continuous several transmission PRS), target BS is cell0, the collision base station is cell1～cell503, and 20 time slots of emulation continuity, simulation result are referring to table 1:

Table 1

	The collision incident	Collide probability
			Prior art	20	5.16e-4
The embodiment of the invention	13	3.36e-4

As can be seen from Table 1, after adopting the prior art scrambling scheme, the collision incident that the PRS that UE receives takes place is 20, the collision probability is 5.16e-4, and the scrambling apparatus that adopts the embodiment of the invention to provide, at first obtain the initialization value of second m sequence, then generate the Gold sequence, utilize this Gold sequence that PRS is carried out scrambling then, the collision incident that the PRS that makes UE receive takes place is 13, and the collision probability is 3.36e-4, therefore, can find out obviously that the scheme that the embodiment of the invention provides has significantly reduced the collision incident that PRS that UE receives takes place, and has reduced the collision probability.

The embodiment of the invention is by being used as frequency offset information the element of scramble sequence, the initialization value of second m sequence is increased greatly, the scope of the Gold sequence of generation is also increased greatly, after utilizing this Gold sequence that PRS is carried out scrambling, the randomness of PRS has also just increased greatly, thereby reduction that can be bigger collides probability, minimizing collision incident, weaken UE interfering with each other between the PRS that synchronization is received, thereby improved the precision that UE is positioned; Further, because frequency offset information is known, do not increase so generate the complexity of scramble sequence yet; And, owing to increased frequency offset information, increased the initialization value scope of second m sequence, make scrambling scheme that the embodiment of the invention provides with respect to prior art, fully used the register of Gold sequence, reduced the wasting of resources.

Embodiment 2

The embodiment of the invention provides a kind of device that location reference signals is carried out scrambling, scramble sequence is that example is carried out with the Gold sequence in the embodiment of the invention, referring to Fig. 4, this device comprises: information acquisition module 201, scramble sequence generation module 202 and scrambling module 203;

Information acquisition module 201 is used to obtain time slot sequence number n _s, OFDM symbol sequence number l, cell ID

CP length mark N _CP, also be used to obtain the frequency offset information v of PRS _Shift

Wherein, as previously mentioned, n _s, l,

And N _CPBe the information that agreement is reserved in the LTE system, repeat no more herein.Because the frequency offset information difference that adopt at each positioning sub-frame each sub-district, therefore, need the base station when UE issues current positioning sub-frame, get access to the frequency offset information that this positioning sub-frame adopts, promptly need to obtain the frequency offset information of the current PRS that issues.Wherein, frequency offset information v _ShiftObtain manner can for:

Wherein,

Perhaps be:

$v_{\mathrm{shift}}=N_{\mathrm{Cell}}^{\mathrm{ID}}\mathrm{mod}6$

Perhaps be:

$v_{\mathrm{shift}}\left(i\right)=(v_{\mathrm{shift}}(i-1)+\left(\underset{k=i\·10+1}{\overset{i\·10+9}{\mathrm{\Σ}}}c\left(k\right)2^{k-(i\·10+1)}\right)\mathrm{mod}{N}_{\mathrm{sb}}+1){\mathrm{mod}N}_{\mathrm{sb}};$

Wherein, N _Sb=6,

v _shift(-1)＝0，

Perhaps be:

Perhaps be:

$v_{\mathrm{shift}}\left(i\right)=(v_{\mathrm{shift}}(i-1)+\left(\underset{k=i\·10+1}{\overset{i\·10+9}{\mathrm{\Σ}}}c\left(k\right)2^{k-(i\·10+1)}\right)\mathrm{mod}5+1)\mathrm{mod}6$

$v_{\mathrm{shift}}(-1)=N_{\mathrm{Cell}}^{\mathrm{ID}}$

Perhaps be:

$v_{\mathrm{shift}}\left(i\right)=((v_{\mathrm{shift}}(i-1)+\left(\underset{k=i\·10+1}{\overset{i\·10+9}{\mathrm{\Σ}}}c\left(k\right)2^{k-(i\·10+1)}\right)\mathrm{mod}5+1)\mathrm{mod}6+N_{\mathrm{Cell}}^{\mathrm{ID}})\mathrm{mod}6$

v _shift(-1)＝0

Perhaps be:

$v_{\mathrm{shift}}\left(i\right)=(w\left(i\right)+N_{\mathrm{Cell}}^{\mathrm{ID}})\mathrm{mod}6;$

Wherein, $w\left(i\right)=(w(i-1)+\left(\underset{k=i\·10+1}{\overset{i\·10+9}{\mathrm{\Σ}}}c\left(k\right)2^{k-(i\·10+1)}\right)\mathrm{mod}5+1)\mathrm{mod}6$

w(-1)＝0

Obtaining frequency offset information v _ShiftThe various forms of expression in, c () is the Gold sequence, and the initialization value of this c () is

T, j and k represent the variable of calculation times, and mod represents to get surplus, and i represents subframe numbers, 6 kinds of frequency location modes of deflection of 6 expressions.

Those skilled in the art can know that frequency offset information can as above several modes acquire, and also can adopt other mode to obtain, and the embodiment of the invention is not done any restriction to this.

As previously mentioned, because the frequency shift (FS) pattern of PRS has and has only 6 kinds in the LTE system, and LTE number of base stations that system supports is 504, therefore for UE, at synchronization, the frequency shift (FS) position of the PRS of two base stations of receiving may be identical, and this just makes PRS interfere with each other easily, collision incident, the accurate location that just can not realize UE take place in the PRS that causes UE to receive.In order effectively to avoid the problems referred to above, need carry out scrambling to PRS handles, the content that the device that the embodiment of the invention provides obtains based on information acquisition module 201, obtain the Gold sequence, utilize this Gold sequence that PRS is carried out scrambling, increasing reduces PRS further the collision incident takes place the degree of randomization of the PRS that issues.See scramble sequence generation module 202 for details:

Scramble sequence generation module 202 is used for the n that obtains according to information acquisition module 201 _s, l,

N _CPAnd v _ShiftGenerate scramble sequence;

Scrambling module 203 is used for according to the scramble sequence that scramble sequence generation module 202 generates PRS being carried out scrambling.

Wherein, scramble sequence generation module 202 specifically comprises:

First acquiring unit is used to obtain the initialization value of first m sequence;

Second acquisition unit is used for the n that obtains according to information acquisition module 201 _s, l, N _CPAnd v _Shift, obtain the initialization value c of second m sequence _Init

Generation unit, the initialization value of second m sequence that the initialization value of first m sequence that is used for obtaining according to first acquiring unit and second acquisition unit obtain generates scramble sequence.

Wherein, as shown in Figure 1, the initialization value that generates first m sequence of Gold sequence is fixed, so generate the Gold sequence that the initialization value of second m sequence of Gold sequence directly affects generation.

Concrete, second acquisition unit obtains the initialization value c of second m sequence _InitConcrete formula be:

1)、 $c_{\mathrm{init}}=2^{10}\·(7\·(n_{\text{s}}+1)+l+1)\·((v_{\mathrm{shift}}+1)\·2\·N_{\mathrm{ID}}^{\mathrm{cell}}+1)+2\·N_{\mathrm{ID}}^{\mathrm{cell}}+N_{\mathrm{CP}}\·\·\·\left(4\right)$

In the formula (4), c _InitBe the initialization value of second m sequence generating the Gold sequence, n _sFor time slot sequence number, l be OFDM symbol sequence number, Be cell ID, N _CPBe the CP length mark.

Perhaps,

2)、 $c_{\mathrm{init}}=2^{10}\·(7\·(n_{\text{s}}+1)+l+1)\·(v_{\mathrm{shift}}+1)\·(2\·N_{\mathrm{ID}}^{\mathrm{cell}}+1)+2\·N_{\mathrm{ID}}^{\mathrm{cell}}+N_{\mathrm{CP}}\·\·\·\left(5\right)$

In the formula (5), c _InitBe the initialization value of second m sequence generating the Gold sequence, n _sFor time slot sequence number, l be OFDM symbol sequence number,

Be cell ID, N _CPBe the CP length mark.

Need to prove that the embodiment of the invention has only been enumerated two kinds of formula (4) and (5) of calculating the initialization value of second the m sequence that generates the Gold sequence, but is not limited to this two formula (4) and (5).

To sum up, by with the element of frequency offset information, thereby strengthen degree of randomization, further, reduce PRS the collision incident takes place the PRS that issues as the scramble sequence of PRS being carried out scrambling (present embodiment is the Gold sequence).

The CRS scrambling formula of prior art

In, because n _sSmaller or equal to 19, l is smaller or equal to 6,

Smaller or equal to 503, N _CPSmaller or equal to 1, can obtain c _Init≤ 2 ²⁸-1, the initialization value scope of second m sequence that promptly generates the Gold sequence is 0～(2 ²⁸-1), and in the formula (6) and (7) of frequency offset information with PRS provided by the invention, because n as the scramble sequence element that PRS is carried out scrambling _sSmaller or equal to 19, l is smaller or equal to 6,

Smaller or equal to 503, N _CPSmaller or equal to 1, v _ShiftSmaller or equal to 5, can obtain c _Init≤ 2 ³⁰-1, the initialization value scope of second m sequence that promptly generates the Gold sequence is 0～(2 ³⁰-1), can obviously find out, the initialization value scope that generates second m sequence of Gold sequence has increased greatly with respect to prior art, because the Gold sequence has direct relation with second the m sequence that generates the Gold sequence, after the initialization value scope of second m sequence increases, the scope of the Gold sequence that generates also just increases greatly, after utilizing this Gold sequence that PRS is carried out scrambling, also just increased the randomness of PRS, reduce the collision probability of the PRS that UE receives at synchronization, thereby increased the accuracy of UE location.And c from the prior art acquisition _Init≤ 2 ²⁸As can be seen, in 31 registers that the Gold sequence provides, only used 28 registers in-1, so the scrambling scheme of prior art do not make full use of Gold sequence 31 bit registers, and the c that calculates from the scrambling apparatus that the embodiment of the invention provides _Init≤ 2 ³⁰Find out in-1 that the scrambling apparatus that the embodiment of the invention provides has used 30 registers,, made full use of the register of Gold sequence, reduced the wasting of resources with respect to prior art.

The embodiment of the invention is by being used as frequency offset information the element of scramble sequence, the initialization value of second m sequence is increased greatly, the scope of the Gold sequence of generation is also increased greatly, after utilizing this Gold sequence that PRS is carried out scrambling, the randomness of PRS has also just increased greatly, thereby reduction that can be bigger collides probability, minimizing collision incident, weaken UE interfering with each other between the PRS that synchronization is received, thereby improved the precision that UE is positioned; Further, because frequency offset information is known, do not increase so generate the complexity of scramble sequence yet; And, owing to increased frequency offset information, increased the initialization value scope of second m sequence, make scrambling apparatus that the embodiment of the invention provides with respect to prior art, fully used the register of Gold sequence, reduced the wasting of resources.

The embodiment of the invention can utilize software to realize that corresponding software programs can be stored in the storage medium that can read, for example, and in the hard disk of computer, buffer memory or the CD.

The above only is preferred embodiment of the present invention, and is in order to restriction the present invention, within the spirit and principles in the present invention not all, any modification of being done, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (10)

1. the method that location reference signals is carried out scrambling is characterized in that, described method comprises:

Obtain time slot sequence number n _s, orthogonal frequency division multiplex OFDM symbol sequence number l, cell ID

Cyclic prefix CP length mark N _CPObtain the frequency offset information v of location reference signals PRS _Shift

According to the described n that obtains _s, l,

N _CPAnd v _ShiftGenerate scramble sequence;

According to described scramble sequence described PRS is carried out scrambling.

2. method according to claim 1 is characterized in that, according to the described n that obtains _s, l, N _CPAnd v _ShiftGenerate scramble sequence, comprising:

Obtain the initialization value of first m sequence;

According to described n _s, l,

N _CPAnd v _Shift, obtain the initialization value c of second m sequence _Init

Generate scramble sequence according to the initialization value of described first m sequence and the initialization value of described second m sequence.

3. method according to claim 2 is characterized in that, according to described n _s, l,

N _CPAnd v _Shift, obtain the initialization value c of second m sequence _Init, be specially:

$c_{\mathrm{init}}=2^{10}\·(7\·(n_{\text{s}}+1)+l+1)\·((v_{\mathrm{shift}}+1)\·2\·N_{\mathrm{ID}}^{\mathrm{cell}}+1)+2\·N_{\mathrm{ID}}^{\mathrm{cell}}+N_{\mathrm{CP}}$

Wherein, c _InitBe the initialization value of second m sequence, n _sFor time slot sequence number, l be OFDM symbol sequence number,

Be cell ID, N _CPBe CP length mark, v _ShiftBe frequency offset information.

4. method according to claim 2 is characterized in that, according to described n _s, l,

N _CPAnd v _Shift, obtain the initialization value c of second m sequence _Init, be specially:

$c_{\mathrm{init}}=2^{10}\·(7\·(n_{\text{s}}+1)+l+1)\·(v_{\mathrm{shift}}+1)\·(2\·N_{\mathrm{ID}}^{\mathrm{cell}}+1)+2\·N_{\mathrm{ID}}^{\mathrm{cell}}+N_{\mathrm{CP}}$

Wherein, c _InitBe the initialization value of second m sequence, n _sFor time slot sequence number, l be OFDM symbol sequence number,

Be cell ID, N _CPBe CP length mark, v _ShiftBe frequency offset information.

5. according to any described method of claim 1-4, it is characterized in that, obtain the frequency offset information v of location reference signals PRS _Shift, be specially:

Wherein,

Or: $v_{\mathrm{shift}}=N_{\mathrm{Cell}}^{\mathrm{ID}}\mathrm{mod}6$

Or: $v_{\mathrm{shift}}\left(i\right)=(v_{\mathrm{shift}}(i-1)+\left(\underset{k=i\·10+1}{\overset{i\·10+9}{\mathrm{\Σ}}}c\left(k\right)2^{k-(i\·10+1)}\right)\mathrm{mod}{N}_{\mathrm{sb}}+1){\mathrm{mod}N}_{\mathrm{sb}};$

Wherein, N _Sb=6; v _Shift(1)=0;

Or:

Wherein,

Or: $v_{\mathrm{shift}}\left(i\right)=((v_{\mathrm{shift}}(i-1)+\left(\underset{k=i\·10+1}{\overset{i\·10+9}{\mathrm{\Σ}}}c\left(k\right)2^{k-(i\·10+1)}\right)\mathrm{mod}5+1)\mathrm{mod}6+N_{\mathrm{Cell}}^{\mathrm{ID}})\mathrm{mod}6;$

Wherein, v _Shift(1)=0;

Or: $v_{\mathrm{shift}}\left(i\right)=(w\left(i\right)+N_{\mathrm{Cell}}^{\mathrm{ID}})\mathrm{mod}6$

Wherein, $w\left(i\right)=(w(i-1)+\left(\underset{k=i\·10+1}{\overset{i\·10+9}{\mathrm{\Σ}}}c\left(k\right)2^{k-(i\·10+1)}\right)\mathrm{mod}5+1)\mathrm{mod}6;$ w(-1)＝0；

Wherein, v _ShiftThe expression frequency offset information, c () is a scramble sequence, and the initial value of described c () is a cell ID

T, j and k represent the variable of calculation times, and i represents subframe numbers, and mod represents to get surplus.

6. the device that location reference signals is carried out scrambling is characterized in that, described device comprises: information acquisition module, scramble sequence generation module and scrambling module;

Described information acquisition module is used to obtain time slot sequence number n _s, orthogonal frequency division multiplex OFDM symbol sequence number l, cell ID

Cyclic prefix CP length mark N _CPAlso be used to obtain the frequency offset information v of location reference signals PRS _Shift

Described scramble sequence acquisition module is used for the n that obtains according to described information acquisition module _s, l,

N _CPAnd v _ShiftGenerate scramble sequence;

Described scrambling module is used for according to the scramble sequence that described scramble sequence generation module generates described PRS being carried out scrambling.

7. device according to claim 6 is characterized in that, described scramble sequence generation module specifically comprises:

First acquiring unit is used to obtain the initialization value of first m sequence;

Second acquisition unit is used for the n that obtains according to described information acquisition module _s, l,

N _CPAnd v _Shift, obtain the initialization value c of second m sequence _Init

Generation unit, the initialization value that is used for the initialization value of first m sequence of obtaining according to described first acquiring unit and second m sequence that described second acquisition unit obtains generates scramble sequence.

8. device according to claim 7 is characterized in that, described second acquisition unit obtains the initialization value c of second m sequence _InitConcrete formula be:

$c_{\mathrm{init}}=2^{10}\·(7\·(n_{\text{s}}+1)+l+1)\·((v_{\mathrm{shift}}+1)\·2\·N_{\mathrm{ID}}^{\mathrm{cell}}+1)+2\·N_{\mathrm{ID}}^{\mathrm{cell}}+N_{\mathrm{CP}};$

Wherein, c _InitBe the initialization value of second m sequence, n _sFor time slot sequence number, l be orthogonal frequency division multiplex OFDM symbol sequence number,

Be cell ID, N _CPBe cyclic prefix CP length mark, v _ShiftBe frequency offset information.

9. device according to claim 7 is characterized in that, described second acquisition unit obtains the initialization value c of second m sequence _InitConcrete formula be:

$c_{\mathrm{init}}=2^{10}\·(7\·(n_{\text{s}}+1)+l+1)\·(v_{\mathrm{shift}}+1)\·(2\·N_{\mathrm{ID}}^{\mathrm{cell}}+1)+2\·N_{\mathrm{ID}}^{\mathrm{cell}}+N_{\mathrm{CP}};$

Wherein, c _InitBe the initialization value of second m sequence, n _sFor time slot sequence number, l be OFDM symbol sequence number,

Be cell ID, N _CPBe CP length mark, v _ShiftBe frequency offset information.

10. according to any described device of claim 6-9, it is characterized in that the frequency offset information that described information acquisition module obtains is:

Wherein,

Or: $v_{\mathrm{shift}}=N_{\mathrm{Cell}}^{\mathrm{ID}}\mathrm{mod}6$

Or: $v_{\mathrm{shift}}\left(i\right)=(v_{\mathrm{shift}}(i-1)+\left(\underset{k=i\·10+1}{\overset{i\·10+9}{\mathrm{\Σ}}}c\left(k\right)2^{k-(i\·10+1)}\right)\mathrm{mod}{N}_{\mathrm{sb}}+1){\mathrm{mod}N}_{\mathrm{sb}};$

Wherein, N _Sb=6; v _Shift(1)=0;

Or:

Wherein,

Or: $v_{\mathrm{shift}}\left(i\right)=(v_{\mathrm{shift}}(i-1)+\left(\underset{k=i\·10+1}{\overset{i\·10+9}{\mathrm{\Σ}}}c\left(k\right)2^{k-(i\·10+1)}\right)\mathrm{mod}5+1)\mathrm{mod}6;$

$v_{\mathrm{shift}}(-1)=N_{\mathrm{Cell}}^{\mathrm{ID}};$

Or: $v_{\mathrm{shift}}\left(i\right)=((v_{\mathrm{shift}}(i-1)+\left(\underset{k=i\·10+1}{\overset{i\·10+9}{\mathrm{\Σ}}}c\left(k\right)2^{k-(i\·10+1)}\right)\mathrm{mod}5+1)\mathrm{mod}6+N_{\mathrm{Cell}}^{\mathrm{ID}})\mathrm{mod}6;$

Wherein, $v_{\mathrm{shift}}(-1)=0;$

Or: $v_{\mathrm{shift}}\left(i\right)=(w\left(i\right)+N_{\mathrm{Cell}}^{\mathrm{ID}})\mathrm{mod}6$

Wherein, $w\left(i\right)=(w(i-1)+\left(\underset{k=i\·10+1}{\overset{i\·10+9}{\mathrm{\Σ}}}c\left(k\right)2^{k-(i\·10+1)}\right)\mathrm{mod}5+1)\mathrm{mod}6;$ w(-1)＝0；

Wherein, v _ShiftThe expression frequency offset information, c () is a scramble sequence, and the initial value of described c () is a cell ID

T, j and k represent the variable of calculation times, and i represents subframe numbers, and mod represents to get surplus.

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