CN102036408A - Equipment and method for transmitting and receiving random access preamble - Google Patents

Abstract

The invention provides equipment and a method for transmitting and receiving a random access preamble. The equipment comprises a physical layer for transmitting burst comprising the preamble. The preamble comprises a first Zadoff-Chu sequence and a second Zadoff-Chu sequence, and each sequence has the length of N. The first Zadoff-Chu sequence is a periodic sequence of a first sequence index, and the period of the periodic sequence is equal to N; and the second Zadoff-Chu sequence is a periodic sequence of a second sequence index, and the period of the periodic sequence is equal to N.

Description

Be used to transmit and receive the equipment and the method for random access guiding

Technical field

Present disclosure relates to communication system, relates more specifically to cell phone system, and more specifically he relates to leading (preamble) of the access attempts at random that is used for cell phone system.

Background technology

Frequency spectrum is reused by spatial coverage being divided into a plurality of sub-districts by the mobile cellular telephone system, and identical frequency spectrum is reused in each sub-district.Fig. 1 shows this situation with plain mode, shows the sub-district 102 that has base station (BS) 104 and subscriber equipment (UE) 106A, 106B and 106C.In fact, UE is the communication equipment that utilizes cellular telephony, such as cell phone or have the computer of unruled card.UE can be static, perhaps can be in the moving vehicle.For for simplicity,, but in practice, in any single subdistrict, can there be this kind equipment of bigger quantity only at three UE shown in the sub-district 102.

Can adopt various signaling schemes to communicate by letter with BS in this sub-district to allow to share a plurality of UE of a sub-district.Example comprises TDMA (time division multiple access), FDMA (frequency division multiple access), CDMA (code division multiple access) and OFDMA (OFDM), more than only lift several examples.Some system can be used for downlink communication (BS is to UE) with a signaling schemes, and another signaling schemes is used for uplink communication (UE is to BS).In addition, system can utilize different signaling schemes according to the information that exchanges between UE and BS.For example, setting up calling between UE and the BS can utilize and setting up the different signaling schemes that calling and voice or data content are just utilizing under the situation in exchange process.

The cell phone system of current and following conception is utilized Random Access Channel (RACH).RACH is based on the communication channel of competition, and it is used for carrying and inserts transmission at random.For some cellular system, the RACH channel can use the ALOHA agreement.Then, can use other agreements based on competition.When physical layer (PHY) rank is discussed the RACH channel, it can be called PRACH (Physical Random Access Channel).

When UE wishes to set up with being connected of BS, can use the RACH channel, thereby dial outgoing call.The RACH channel can be used for various signal processing purposes, such as being used for regularly adjusting (synchronously), power adjustments and resource request, more than only lift several examples.As a specific example, power adjustments can be utilized so-called open Loop Power control agreement.In this agreement, UE is to the BS transmission preamble, and if BS do not reply that this is leading, UE transmits once more that this is leading so, but is to transmit once more with high power more.This process continues always, and by force to being enough to be used in reception, in this, BS sends to UE and replys up to the signal strength signal intensity that receives at the BS place.Following RACH channel can utilize other agreement to carry out power adjustments.

The PRACH burst comprises that access (RA) is leading at random, to identify access attempts at random.Leading signature and the Cyclic Prefix of comprising of RA, wherein this Cyclic Prefix appends to signature, to help to alleviate ICI (interchannel interference) and ISI (intersymbol interference).UE can be according to selecting concrete RA leading based on the agreement of competition.In 3GPP LTE (third generation partner program Long Term Evolution) standard, propose Zadoff-Chu (ZC) sequence and will be used for the RA signature.3GPP is for the purpose of setting up 3G (third generation) mobile telephone system standard, the cooperation agreement of setting up in December, 1998.3GPP LTE is the plan that 3GPP inside is used to improve UMTS (Universal Mobile Telecommunications System) mobile phone standard.Referring to http://www.3gpp.org.

Mobile UE suffers Doppler frequency shift (DFO) when moving with respect to BS.For high mobility UE, the DFO of generation may cause unacceptable detection mistake in the decoding to the ZC sequence, thereby causes the alert rate of high mistake.Proposed some based on the scheme that repeats, detected performance thereby improve, but think that this type of scheme does not overcome the DFO problem fully, especially under serious relatively DFO condition.

Summary of the invention

As described,, there is related sequence index for each ZC sequence in embodiment.For the execution mode of UE, be used for the RACH burst of access attempts at random, leading in the RACH burst comprises two ZC sequences, wherein the difference of the sequence index of these two ZC sequences has identified the UE of access attempts at random.For the execution mode of the BS that receives the RACH burst, two sequences of recovery from this is leading, and with these two sequences divided by provider's sequence.If this factor sequence is the ZC sequence, then the index sequence of this factor sequence identifies access attempts at random.

In one embodiment, a kind of equipment comprises that physical layer has leading burst with transmission.A this leading Zadoff-Chu sequence and the 2nd Zadoff-Chu sequence of comprising, each sequence all has length N.The one Zadoff-Chu sequence is the periodic sequence that the cycle of first sequence index equals N, and the 2nd Zadoff-Chu sequence is the periodic sequence that the cycle of second sequence index equals N.

For example, the difference of first and second sequence index can be the integer of selecting from the set with N integer, and not having two integers in the set of the described N of a having integer is the congruence of mould N each other (congruent).In a kind of situation, the set of the described N of a having integer is [0, N-1].

In other embodiments, to be selected from the Zadoff-Chu sequence right for a Zadoff-Chu sequence.For example, the Zadoff-Chu sequence is to can comprising the first candidate Zadoff-Chu sequence with first candidate sequence index, and the second candidate Zadoff-Chu sequence with second candidate sequence index.When N was even number, the difference of the first and second candidate sequence index was congruences of N/2 mould N.In a specific implementations, the first candidate sequence index equals the 0 and second candidate sequence index and equals N/2.For example, first difference and second difference of the first candidate sequence index and the second candidate sequence index of the first candidate sequence index and the second candidate sequence index can be the integers of selecting from the set with N integer, and not having two integers in this has the set of N integer is congruences of mould N each other.

In another embodiment, the Zadoff-Chu sequence is to comprising the first candidate Zadoff-Chu sequence with first candidate sequence index, and the second candidate Zadoff-Chu sequence with second candidate sequence index.When N was odd number, the difference of the first and second candidate sequence index was the congruence of (N-1)/2 mould N or (N+1)/2 congruence of mould N.In one example, the first candidate sequence index can equal 0, and the second candidate sequence index can equal (N-1)/2 or (N+1)/2.For example, first difference and second difference of the first candidate sequence index and the second candidate sequence index of the first candidate sequence index and the second candidate sequence index can be the integers of selecting from the set with N integer, and not having two integers in the set with N integer is congruences of mould N each other.

In another execution mode, equipment comprises that physical layer comprises leading burst with reception, and recovery length is first sequence of N and second sequence that length is N from leading.Can use divider with first sequence item by item divided by second sequence, so that the factor sequence with length N to be provided.In one embodiment, can use the coherent detection unit to carry out the periodic Zadoff-Chu sequence that factor sequence and length equal N as cycle of N and sequence index relevant.For example, the coherent detection unit can be that the 2nd Zadoff-Chu sequence of N is carried out relevant with first sequence and from the length that preselected Zadoff-Chu sequence centering is selected.In a specific example, preselected Zadoff-Chu sequence is to comprising that length is N and the first candidate Zadoff-Chu sequence with first candidate sequence index, and length is N and the second candidate Zadoff-Chu sequence with second candidate sequence index.When being even number value for N, the difference of the first and second candidate sequence index is congruences of N/2 mould N, and is odd number value for N, and the difference of the first and second candidate sequence index is (N-1)/2 or (N+1)/2 congruence of mould N.

In another embodiment, a kind of method is disclosed.Transmission comprises leading burst.A this leading Zadoff-Chu sequence and the 2nd Zadoff-Chu sequence of comprising, each sequence all has length N.The one Zadoff-Chu sequence is the periodic sequence that the cycle of first sequence index equals N, and the 2nd Zadoff-Chu sequence is the periodic sequence that the cycle of second sequence index equals N.

In one embodiment, the difference of first and second sequence index is integers of selecting from the set with N integer, and not having two integers in this has the set of N integer is congruences of mould N each other.This set with N integer for example can be [0, N-1].

In the additive method execution mode, reception comprises leading burst.Be similar to preamble, this a leading Zadoff-Chu sequence and the 2nd Zadoff-Chu sequence of comprising, each sequence all has length N.The one Zadoff-Chu sequence is the periodic sequence that the cycle of first sequence index equals N, and the 2nd Zadoff-Chu sequence is the periodic sequence that the cycle of second sequence index equals N.From this is leading, recover to have first sequence and second sequence of length N with length N.With first sequence item by item divided by second sequence so that the factor sequence with length N to be provided.

In one embodiment, be that the Zadoff-Chu sequence of N is carried out relevant with factor sequence and length.For example, can be that the 2nd Zadoff-Chu sequence of N is carried out relevant with first sequence and from the length that preselected Zadoff-Chu sequence centering is selected.The difference of first and second sequence index is integers of selecting from the set with N integer, and not having two integers in this has the set of N integer is congruences of mould N each other.For example, this set with N integer can be [0, N-1].

Provide the foregoing invention content part to select with the notion that is introduced in the reduced form that further describes in the following embodiment part.Key feature or essential feature that this summary of the invention part is not intended to identify claimed theme, the scope that also is not intended to be used for the theme of requirement for restriction protection.

Description of drawings

In order more completely to understand present disclosure and its advantage, now in conjunction with the accompanying drawings also with reference to following description, in the accompanying drawings:

Fig. 1 shows the cell phone system of prior art;

Fig. 2 shows protocol stack that is used for UE and BS and the preamble structure according to execution mode of the present disclosure;

Fig. 3 shows the flow chart according to execution mode of the present disclosure; And

Fig. 4 shows the flow chart according to another execution mode of the present disclosure.

Embodiment

Go through the realization and the use of current preferred implementation below.Yet, should be understood that the disclosure provides a lot of invention designs that are suitable for, these designs can realize in various concrete environment.The embodiment of being discussed only is for the explanation that realizes and use concrete mode of the present invention, and does not limit the scope of the invention.

In the following description, the scope of term " some execution mode " does not limit it and means a more than execution mode, but this scope can comprise an execution mode, more than one execution mode, maybe may comprise all execution modes.

Length is that the ZC sequence of N can be expressed as { a _u(k), k=0,1 ..., N-1}, wherein u is an index, u=0,1 ..., N-1, and can be called sequence index.ZC sequence { a _u(k), k=0,1 ..., N-1} can be generated by following formula

$a_u\left(k\right)=\exp (-\mathrm{j\πu}\frac{k-(k+1)}{N}),$ k＝0，1，...，N-1。

According to above-mentioned expression formula, can see a _u(k) be periodic, the cycle of its index u equals N.Also observe easily from above-mentioned expression formula, the DFT of ZC sequence (discrete Fourier transform (DFT)) is another ZC sequence.That is, DFT is mapped as a ZC sequence another ZC sequence of equal length.Thereby no matter consider in time domain or in frequency domain, the character of ZC sequence all is identical.For the ease of mark, ZC sequence { a _u(k), k=0,1 ..., N-1} will be by a _uExpression.

Can describe execution mode at the simplification protocol stack shown in Fig. 2,202 the PRACH burst (burst) that is labeled as shown in it has and comprises and be labeled as the leading of two ZC sequences of 204 and 206.Except these two ZC sequences, PRACH burst 202 also comprises Cyclic Prefix 208 and guard time 210.During guard time 210, not transmission of PRACH burst 202.Execution mode can be located to realize, comprise the leading of two ZC sequences to provide to have in the physical layer (being labeled as PHY layer 212UE) of UE; And execution mode can be located realization in the physical layer (being labeled as PHY layer 212BS) of BS, and is leading to recover this, thereby identifies access attempts at random.Among UE or the BS some or all physical layer function can realize by one or more integrated circuits, such as ASIC (application-specific integrated circuit (ASIC)) and/or FPGA (field programmable gate array), more than only lift two examples.

According to its definition, the ZC sequence is a sequence of complex numbers.As everyone knows, can pass through the Channel Transmission plural number in the sense, that is, the in-phase component of its real part modulation bandpass signal, and imaginary part is modulated the quadrature component of this bandpass signal.Demodulation will recover homophase and quadrature component.For example, in the situation of OFDMA, the ZC sequence that constitutes UE RACH burst is carried out IDFT (discrete Fourier transform (DFT) inverse transformation), insert Cyclic Prefix then, and upconvert to RF (radio frequency) carrier wave then.When receiving, the RF signal is downconverted to baseband signal (complex value with homophase and quadrature component), remove Cyclic Prefix, and carry out DFT to recover the ZC sequence.

ZC sequence 204 and 206 in the RACH burst 202 of Fig. 2 can be respectively by a _U1And a _U2Expression.That is,

$a_{u1}\left(k\right)=\exp (-\mathrm{j\π}{u}_1\frac{k(k+1)}{N}),$ k＝0，1，...，N-1

And

$a_{u2}\left(k\right)=\exp (-\mathrm{j\π}{u}_2\frac{k(k+1)}{N}),$ k＝0，1，...，N-1

For fear of in subscript, applying mechanically subscript, as the following timestamp that serves as ZC sequence 204, index u ₁Be written as u1.Similar labelling method is applied to u ₂With ZC sequence 206.

For having the ZC of comprising sequence a _U1And a _U2Leading RACH burst, order

Be illustrated in the BS place from ZC sequence a _U1The sequence of recovering, and order

Be illustrated in the BS place from ZC sequence a _U2The sequence of recovering.

According to some execution mode, be used for the leading sequence index u that has that comprises of UE RACH burst ₁And u ₂Satisfy 0≤u ₁-u ₂The ZC sequence of≤N-1, wherein poor Δ u ≡ u ₁-u ₂Sign UERACH inserts at random.At the BS place, the sequence of recovery

Every divided by the sequence of recovering

The item of correspondence to produce factor sequence.If this factor sequence produces the ZC sequence, the index of the factor sequence that then obtains is identified by Δ u, thereby identifies access attempts at random.In other words, if for each k=0,1 ..., N-1, merchant Make q (k)=a _v(k), { a wherein _v(k), k=0,1 ..., N-1} is the ZC sequence of index v, then identifies the poor Δ u that UE RACH inserts at random and is estimated as Δ u=v.

Top description can be represented by the figure of Fig. 3.UE carries out the function by 302,304 and 306 indications.At the UE place, generate (302) two ZC sequences, be expressed as a _U1And a _U2, carry out IDFT (304) afterwards.Comprising a _U1And a _U2Leading back insert (306) Cyclic Prefix, and by Channel Transmission RACH burst (308).Function by 312,314,316,318 and 320 indications is carried out by BS.Remove (312) Cyclic Prefix, carry out DFT (314) afterwards.Recover (316) sequence

With

With

As dividend and

Carry out division (318) as divisor.The merchant that coherent detection (320) identification obtains is the ZC sequence, and the index of this merchant ZC sequence sign UE inserts at random.

Expect that above-mentioned execution mode helps to alleviate the DFO in the sign that UE inserts at random.This can followingly illustrate.For desirable OFDMA channel (noiseless and do not have ISI and ICI), because the sequence that DFO receives can be expressed as

${\hat{a}}_{u1}\left(k\right)=\exp (-\mathrm{j\π}{u}_1\frac{k(k+1)}{N})\exp \left(j2\mathrm{\π\Δf}\frac{\mathrm{kt}}{N}\right),$ k＝0，1，...，N-1，

With

${\hat{a}}_{u2}=\left(k\right)=\exp (-\mathrm{j\π}{u}_2\frac{k(k+1)}{N})\exp \left(j2\mathrm{\π\Δf}\frac{\mathrm{kt}}{N}\right),$ k＝0，1，...，N-1，

Wherein Δ f is the frequency displacement owing to Doppler frequency shift, and T is the length (in time domain) of ZC sequence.The relative velocity of above-mentioned expression formula hypothesis UE and BS is constant in signal duration among the T basically.At each k=0,1 ..., N will

Divided by

Produce factor sequence q, wherein

$q\left(k\right)\≡\frac{{\hat{a}}_{u1}\left(k\right)}{{\hat{a}}_{u2}\left(k\right)}=\exp (-\mathrm{j\π\Δu}\frac{k(k+1)}{N})=a_{u1-u2}\left(k\right),$ k＝0，1，...，N-1。

As can be seen, owing to DFO's

Divided by

Expression formula in phase factor

When carrying out division by cancellation, thereby utilize ZC sequence a easily _{Δ u}Identify factor sequence q.In addition, because the minimum period of each ZC sequence is N, and, insert at random so identify UE clearly because the poor Δ u of sequence index is chosen as by UE to be belonged to integer and gather [0, N-1].

For given leading cost, above-mentioned execution mode is weighed between the influence of opposing DFO and clear and definite leading quantity.For example, if be that the leading lengths table of unit is shown N with the symbol _p, then use length to be N _pThe prior art systems of single ZC sequence allow N in the sub-district _pIndividual clear and definite UE RACH inserts at random, but is to be cost with the susceptibility to DFO.By use two ZC sequences in leading as above-mentioned execution mode, the length of each ZC sequence is N _p/ 2 (easy in order to discuss, suppose N _pBe even number), thus N can be held _p/ 2 clear and definite UE RACH insert at random, but can expect to have bigger robustness in the influence of this type of execution mode for opposing DFO.

By in leading, using ZC sequence, can hold the clear and definite access at random of larger amt in the sub-district, but for this type of short ZC sequence, the alert rate of mistake may rise more than two.For example, some execution mode can be designed to have three ZC sequences, i.e. a _U1, a _U2And a _U3, and can derive two factor sequences,

With

The second sequence index difference Δ u ₂The extra degree of freedom of permission in sign UE RACH inserts at random.Yet the length of each ZC sequence reduces (to suppose N now _pBe odd number) be N _p/ 3, this has increased for the alert rate of the mistake of specific Z C sequence.Thereby this type of execution mode is weighed between undesirable character of shorter ZC sequence and the admissible clear and definite quantity that inserts at random.

Some execution mode increases the quantity that clear and definite RACH inserts at random, and does not increase the quantity of leading middle ZC sequence.An execution mode can be described below.With first in leading (in burst 202, counting from left to right) ZC sequence selection is a ₀Or a _N/2(easy in order to discuss, suppose that N is an even number.Know that from discuss how revising description is the situation of odd number to handle N).If selected a ₀, the 2nd ZC sequence in then leading is a _u, u ∈ [0, N-1] wherein.If a that has been a ZC sequence selection _N/2, the 2nd ZC sequence in then leading is a _u, but u ∈ [N/2, N-1] wherein now.In other words, in last situation, be a ZC sequence selection a ₀, the difference of the sequence index between the first and second ZC sequences can adopted value Δ u=0, and 1 ..., N-1; Yet, in one situation of back, when being a ZC sequence selection a _N/2The time, the difference of the sequence index between the first and second ZC sequences can value Δ u=0, and 1 ..., N/2-1.

BS not only is each k provider as before

And BS is also by right

Carry out coherent detection and distinguish selection a ₀Or a _N/2Two kinds of situations as a ZC sequence.Because a ₀Or a _N/2In the sequence index space, be ultimate range,, strengthened coherent detection substantially so select two ZC sequences to compare less than the centering of N/2 with interval from index space.For being a ZC sequence selection a ₀Situation, the clear and definite quantity that inserts at random is N, and for being a ZC sequence selection a _N/2Situation, the clear and definite quantity that inserts at random is N/2.Thereby for above-mentioned execution mode, the clear and definite total quantity that inserts at random is 3N/2.It should be noted that if be divided by

The time, determine Δ u ∈ [N/2, N-1], can determine that so a ZC sequence is a ₀, and do not need with

With a ₀Relevant.

Execution mode shown in Fig. 3 can be revised as shown in Figure 4.(, need in Fig. 4, not reappear all elements among Fig. 3) for for simplicity.Except the signal processing chain of Fig. 3 indication, in Fig. 4, first sequence of recovering

For coherent detection 418 also is available.If coherent detection 418 determines Δ u and is in the integer set [N/2, N-1], so RACH at random access burst with sequence index difference Δ u sign, and in this situation, a ₀It is the ZC sequence in leading.Yet if determine Δ u in integer set [0, (N/2)-1], coherent detection 418 is also determined

Be a ₀Or a _N/2Then, coherent detection 418 can be distinguished in following two kinds of situations, and promptly the ZC sequence in the burst of transmission is a ₀Or a _N/2, and thereby can clearly identify the RACH burst.

Can under the situation that does not break away from following claimed scope of the present invention, carry out various modifications to described execution mode.For example, in the above-described embodiment, a ZC sequence is defined as first (in proper order) sequence in leading when reading from left to right in burst 202 as shown in Figure 2.Yet selection only is for for simplicity like this.Can describe other execution modes, wherein said " first " ZC sequence is that second (in proper order) sequence in leading and described " second " ZC sequence are first (in proper order) sequences in leading.

In addition, should be understood that the ZC sequence is periodic, the cycle of its sequence index equals N.This means if u is the congruence of v mould N, then a _u=a _vThereby, when describing execution mode, when describing Z C sequence, sequence index can be restricted to integer set [0, N-1] and be without loss of generality.According to this thought, the execution mode of Fig. 3 may be summarized to be can select difference Δ u from the set ζ with N integer, and wherein, not having two integers in set ζ is congruences of mould N each other.

Another modification according to the periodic execution mode of sequence index is, can be with the execution mode shown in term description Fig. 4 more generally, and wherein can be to (a _u, a _v) in select the first and second ZC sequences in leading, wherein the u-v formula is the congruence of N/2 mould N.That is, the first and second ZC sequences are separated N/2 in index space.In addition, these two ZC sequences and the nonessential N/2 that in index space, separates.For example, be the situation of even number for N, two ZC sequences can be separated certain number except N/2 in index space, but can expect that the distance of N/2 has more performance.It should be noted that for N to be the situation of odd number, in some embodiments, the distance in the index space can be (N-1)/2 or (N+1)/2, can also be other values for other execution modes.

Run through the description of execution mode, use various mathematical relationships to describe relation between one or more amounts.For example, mathematical relationship or mathematic(al) manipulation can be represented a kind of like this relation, by this relation, by means of various mathematical operations, such as add, subtract, multiplication and division etc., derive certain amount from one or more other amounts.Perhaps, mathematical relationship can indicate an amount greater than, be less than or equal to another amount.These relations and conversion are not to satisfy fully in practice, and therefore should be interpreted as " being designed to " relation and conversion.Those of ordinary skill in the art can design various useful embodiment and satisfy various mathematical relationships or conversion, but these relations or conversion may be only to the implementor can with the technology tolerance in be met.

Thereby; in following claims; should be understood that; mathematical relationship required for protection or change in practice may be only to the implementor can with the technology tolerance in be met, and the scope of theme required for protection comprises and satisfies claimed like this mathematical relationship or those execution modes of conversion basically.

Although with specific to the language description of structured features and method action execution mode, should be understood that the theme that limits in the appended claims needn't be limited to above-mentioned concrete feature or action.On the contrary, above-mentioned concrete feature or action are open as the exemplary forms that realizes these claims.

Though described the present invention with reference to exemplary embodiment, this description is not intended to be construed as limiting meaning.With reference to described description the time, those skilled in the art will know various modifications and combination and other execution modes of the present invention of exemplary embodiment.Therefore, appended claims is intended to comprise any this type of modification or execution mode.

Claims (22)

1. an equipment comprises;

Physical layer, be used to transmit and comprise leading burst, a described leading Zadoff-Chu sequence and the 2nd Zadoff-Chu sequence of comprising, each sequence all has length N, the cycle that a described Zadoff-Chu sequence is first sequence index equals the periodic sequence of N, and the cycle that described the 2nd Zadoff-Chu sequence is second sequence index equals the periodic sequence of N.

2. equipment according to claim 1, the difference of wherein said first and second sequence index are integers of selecting from the set with N integer, and not having two integers in the set of the described N of a having integer is congruences of mould N each other.

3. equipment according to claim 2, the set of the wherein said N of a having integer are [0, N-1].

4. equipment according to claim 1, it is right that a wherein said Zadoff-Chu sequence is selected from the Zadoff-Chu sequence.

5. equipment according to claim 4, wherein said Zadoff-Chu sequence is to comprising the first candidate Zadoff-Chu sequence with first candidate sequence index, and the second candidate Zadoff-Chu sequence with second candidate sequence index, when wherein N was even number, the difference of the described first and second candidate sequence index was congruences of N/2 mould N.

6. equipment according to claim 5, the wherein said first candidate sequence index equals 0, and the described second candidate sequence index equals N/2.

7. equipment according to claim 6, first difference and second difference of described first candidate sequence index and the described second candidate sequence index of wherein said first candidate sequence index and the described second candidate sequence index are the integers of selecting from the set with N integer, and not having two integers in the set of the described N of a having integer is congruences of mould N each other.

8. equipment according to claim 4, wherein said Zadoff-Chu sequence is to comprising the first candidate Zadoff-Chu sequence with first candidate sequence index, and the second candidate Zadoff-Chu sequence with second candidate sequence index, when wherein N was odd number, the difference of the described first and second candidate sequence index was the congruence of (N-1)/2 mould N or (N+1)/2 congruence of mould N.

9. equipment according to claim 8, the wherein said first candidate sequence index equals 0, and the described second candidate sequence index equals (N-1)/2 or (N+1)/2.

10. equipment according to claim 9, first difference and second difference of described first candidate sequence index and the described second candidate sequence index of wherein said first candidate sequence index and the described second candidate sequence index are the integers of selecting from the set with N integer, and not having two integers in the set of the described N of a having integer is congruences of mould N each other.

11. an equipment comprises:

Physical layer is used to receive and comprises leading burst, and to recover length leading be first sequence of N and second sequence that length is N from described; And

Divider is used for described first sequence item by item divided by described second sequence, is the factor sequence of N so that length to be provided.

12. equipment according to claim 11 further comprises:

The coherent detection unit, being used for described factor sequence and length is that the periodic Zadoff-Chu sequence that equals N in cycle of N and sequence index is carried out relevant.

Carry out relevant 13. equipment according to claim 12, wherein said coherent detection unit further are the 2nd Zadoff-Chu sequence of N with described first sequence and the length of selecting from preselected Zadoff-Chu sequence centering.

14. equipment according to claim 13, wherein said preselected Zadoff-Chu sequence is to comprising that length is N and the first candidate Zadoff-Chu sequence with first candidate sequence index, and length is N and the second candidate Zadoff-Chu sequence with second candidate sequence index, when wherein N is even number, the difference of the described first and second candidate sequence index is congruences of N/2 mould N, and when N was odd number, the difference of the described first and second candidate sequence index was (N-1)/2 or (N+1)/2 congruence of mould N.

15. a method comprises:

Transmission comprises leading burst, a described leading Zadoff-Chu sequence and the 2nd Zadoff-Chu sequence of comprising, each sequence all has length N, the cycle that a described Zadoff-Chu sequence is first sequence index equals the periodic sequence of N, and the cycle that described the 2nd Zadoff-Chu sequence is second sequence index equals the periodic sequence of N.

16. method according to claim 15, the difference of wherein said first and second sequence index are integers of selecting from the set with N integer, not having two integers in the set of the described N of a having integer is congruences of mould N each other.

17. method according to claim 16, the set of the wherein said N of a having integer are [0, N-1].

18. a method comprises:

Reception comprises leading burst, a described leading Zadoff-Chu sequence and the 2nd Zadoff-Chu sequence of comprising, each sequence all has length N, the cycle that a described Zadoff-Chu sequence is first sequence index equals the periodic sequence of N, and described the 2nd Zadoff-Chu sequence cycle that is second sequence index equals the periodic sequence of N;

From described second sequence have first sequence of length N and have length N recovered leading; And

With described first sequence item by item divided by described second sequence, so that the factor sequence with length N to be provided.

19. method according to claim 18 further comprises:

With described factor sequence and length is that the Zadoff-Chu sequence of N is carried out relevant.

20. method according to claim 19 further comprises:

With described first sequence and from the length that preselected Zadoff-Chu sequence centering is selected is that the 2nd Zadoff-Chu sequence of N is carried out relevant.

21. method according to claim 18, the difference of wherein said first and second sequence index are integers of selecting from the set with N integer, not having two integers in the set of the described N of a having integer is congruences of mould N each other.

22. method according to claim 18, the set of the wherein said N of a having integer are [0, N-1].

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