CN102065563A - Method and equipment for generating frequency-domain Zadoff-Chu sequences - Google Patents

Abstract

The invention discloses a method and equipment for generating frequency-domain Zadoff-Chu (ZC) sequences. The method comprises the following steps of: generating time-domain ZC sequences according to a formula; calculating the summation of the time-domain ZC sequences; selecting a time-domain sample point value from the ZC sequences according to a predetermined frequency-domain index value; performing a conjugate operation on the selected time-domain sample point value; obtaining a result obtained by multiplying the time-domain ZC sequence by the time-domain sample point value after the conjugate operation; generating a phase rotation angle according to a predetermined cyclic shift offset; and multiplying the result which is obtained by multiplying the time-domain ZC sequence by the time-domain sample point value after the conjugate operation by the phase rotation angle to obtain the frequency-domain ZC sequence. In the method, the aim of transforming the time-domain ZC sequence into the frequency-domain ZC sequence is fulfilled by adopting a digital signal processing process which is equivalent to discrete Fourier transform (DFT); and the problems of large calculation amount, low operating speed, increased chip area and power and the like in the process of generating the frequency-domain ZC sequence by adopting the DFT because calculation numeric value types are not matched in the prior art are solved.

Description

A kind of generation method and apparatus of frequency domain Zadoff-Chu sequence

Technical field

The present invention relates to wireless communication field, relate in particular to a kind of generation method and apparatus of frequency domain Zadoff-Chu sequence.

Background technology

LTE (Long Term Evolution, Long Term Evolution) system is thought accurate 4G wireless communication system widely, it has the transmission rate of the up 50M of descending 100M, support higher translational speed (350km/h) and bigger coverage radius of cell (100 kilometers) simultaneously, support that 200 users in every sub-district are simultaneously online.In addition, LTE also has band width configuration (1.4M～20M), support multi-media broadcasting service and end-to-end QoS characteristics such as (Quality of Service, service quality) flexibly.Therefore LTE also is considered to following aroused in interest developing direction and the candidate's standard of 4G technology of moving.

Before normal subscriber data traffic, UE (User Experience, user experience) at first will carry out random access procedure, so that be used for adjusting up (Uplink) transmitting time, distributes Radio Network Temporary Identifier (RNTI), at random access interference solution etc.In the up link of LTE, Random Access Channel PRACH is used for initiating user's the request of access at random, and the wherein general signaling procedure that inserts at random as shown in Figure 1.Random access procedure was divided into for four steps, and the first step is that UE sends random access guiding preamble sequence, and second one is that eNodeB sends accidental access response, wherein contains the line time adjustment information, and then UE adjusts up transmitting time according to this adjustment information.The 3rd step and the 4th step are Radio Resource control (Radio Resource Control) protocol signalings.Wherein the first step comprises the generative process of the generative process frequency domain ZC sequence of the Preamble sequence that the present invention relates to.UE will generate according to upper strata sequence of indication selection and according to certain step in 64 predefined Preamble sequences.

Being created in the whole random access procedure of Preamble is in consequence, and Preamble is by the Zadoff-Chu sequence promptly, the ZC sequence, and through cyclic shift, time-frequency conversion, the physical resource mapping generates.It is formula 1 that the time domain of ZC sequence generates formula:

$x_u\left(n\right)=e^{-j\frac{\mathrm{\πun}(n+1)}{N_{\mathrm{ZC}}}},0\≤n\≤N_{\mathrm{ZC}}-1---\left(1\right)$

N wherein _ZCBe sequence length, as shown in Figure 1, be divided into four kinds of forms.U is the generation root of ZC sequence, and for form 0～3, its value is 0～837, and is 0～137 for its value of format 4.

The generating apparatus of ZC sequence as shown in Figure 2 in the prior art, generate the ZC sequence of time domain according to formula 1 by time domain sequences generation unit 21, cycle shift unit 22 is selected the side-play amount of a cyclic shift according to the indication on eNodeB and UE upper strata, ZC sequence to time domain is carried out cyclic shift, and its process can be represented by formula 2:

x _u，v(n)＝x _u((n+C _v)mod?N _ZC) (2)

Wherein, C _vBe by the cyclic shift amount that calculates.Finish the time domain generative process of ZC sequence this moment, and the length of this time domain sequences is 839 or 139, as shown in Figure 1.Carry out discrete Fourier transform through DFT unit 23 then, generate frequency domain ZC sequence, counting of this DFT operation is identical with the length of time domain ZC sequence, is 839 or 139.

By said process as can be seen, the discrete Fourier transform of time domain ZC sequence is obtained in the frequency domain ZC sequence process, its operation is counted neither conventional DFT base-2,4,8 count, and the base of stipulating in neither LTE-2,3,5 DFT counts.So, adopt this mode directly time domain ZC sequence to be carried out conversion, realize the process of or DFT at 839 at 139, it is big that meeting amount of calculation occurs because of the evaluation type does not match, arithmetic speed is slow, and problems such as chip area and power consumption increase further can influence the formation speed of Preamble sequence.

Summary of the invention

In view of this, the invention provides a kind of generation method and apparatus of frequency domain ZC sequence, amount of calculation is big in the prior art, arithmetic speed is slow, problems such as chip area and power consumption increase to solve.Its scheme is specially:

A kind of generation method of frequency domain ZC sequence comprises:

Generate time domain ZC sequence according to formula;

Calculate described time domain ZC sequence and;

From described ZC sequence, select the time domain sample value according to default frequency domain index value;

The time domain sample value of described selection is carried out conjugate operation;

Obtain described time domain ZC sequence and with described conjugate operation after the multiplied result of time domain sample value;

Generate phase rotation angle according to the cyclic shift amount that sets in advance;

Multiply each other with described time domain ZC sequence with the multiplied result and the described phase rotation angle of time domain sample value behind the described conjugate operation, obtain frequency domain ZC sequence.

A kind of generation equipment of frequency domain ZC sequence comprises:

Time domain ZC sequence generating unit is used for generating time domain ZC sequence according to formula;

Sum unit, be used to calculate described time domain ZC sequence and;

The sampling point selected cell is used for selecting the time domain sample value according to default frequency domain index value from described ZC sequence;

Conjugate unit is used for the time domain sample value of described selection is carried out conjugate operation;

First unit that multiplies each other, be used to obtain described time domain ZC sequence and with described conjugate operation after the multiplied result of time domain sample value;

The angle generation unit is used for generating phase rotation angle according to the cyclic shift amount that sets in advance;

Second unit that multiplies each other is used for described first the multiply each other result of unit and the result of described angle generation unit multiplied each other, and obtains frequency domain ZC sequence.

From above-mentioned technical scheme as can be seen, the generation method and apparatus of the disclosed frequency domain ZC sequence of the embodiment of the invention is by adopting the digital signal processing of a series of DFT of being equivalent to conversion, realized time domain ZC sequence transformation is obtained the purpose of frequency domain ZC sequence, do not match owing to the evaluation type thereby solved in the prior art, amount of calculation is big in the employing DFT conversion generation frequency domain ZC sequence process, arithmetic speed is slow, problems such as chip area and power consumption increase.

Simultaneously, because the generative process of frequency domain ZC sequence is the committed step in the Preamble sequence generative process, so, further improved Preamble sequence formation speed.

Description of drawings

In order to be illustrated more clearly in the embodiment of the invention or technical scheme of the prior art, to do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art below, apparently, accompanying drawing in describing below only is some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain other accompanying drawing according to these accompanying drawings.

Fig. 1 is a ZC Format Series Lines schematic diagram;

Fig. 2 is the structural representation of the generation equipment of ZC sequence in the prior art;

Fig. 3 is the flow chart of the embodiment of the invention 1 disclosed frequency domain ZC sequence generation method;

Fig. 4 is the structural representation that the embodiment of the invention 2 disclosed frequency domain ZC sequence generate equipment.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the invention, the technical scheme in the embodiment of the invention is clearly and completely described, obviously, described embodiment only is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills belong to the scope of protection of the invention not making the every other embodiment that is obtained under the creative work prerequisite.

The invention discloses a kind of frequency domain ZC sequence generation method, by a series of digital signal processings that are equivalent to the DFT conversion, realized time domain ZC sequence transformation is obtained the purpose of frequency domain ZC sequence, do not match owing to the evaluation type thereby solved in the prior art, amount of calculation is big in the employing DFT conversion generation frequency domain ZC sequence process, arithmetic speed is slow, problems such as chip area and power consumption increase.Its embodiment is as described below:

Embodiment one

The flow process of the disclosed frequency domain ZC sequence of present embodiment generation method comprises as shown in Figure 3:

Step S31, generate time domain ZC sequence according to formula;

Generate time domain ZC sequence according to formula 1;

Step S32, calculate described time domain ZC sequence and;

Utilize formula 3 sequence of calculations and,

$Z_{\mathrm{sum}}=\underset{n=0}{\overset{N_{\mathrm{ZC}}-1}{\mathrm{\Σ}}}{x}_u\left(n\right)---\left(3\right)$

Step S33, the default frequency domain index value of basis are selected the time domain sample value from described ZC sequence;

The index value of supposing this moment is k, and according to the characteristic of ZC sequence, this moment, the time domain index value corresponding with it was u ' k, and then Ci Shi sample value is x _u(u ' k), wherein u ' satisfies mod (u ' u, N _ZC)=1;

Step S34, the time domain sample value of described selection is carried out conjugate operation;

With described sample value x _u(u ' k) carry out conjugate operation to obtain

Step S35, obtain described time domain ZC sequence and with described conjugate operation after the multiplied result of time domain sample value;

With described With described

Multiply each other according to formula 4,

$Z_u\left(k\right)=Z_{\mathrm{sum}}{x}_u^{*}\left(u^{\′}k\right)---\left(4\right)$

The cyclic shift amount that step S36, basis set in advance generates phase rotation angle;

According to cyclic shift amount C _vAccording to formula 5

$A_{C_v}=e^{\frac{j2\mathrm{\π}{C}_{v}k}{N_{\mathrm{ZC}}}---\left(5\right)}$

Generate the angle of phase place rotation.

Step S37, multiply each other, obtain frequency domain ZC sequence with described time domain ZC sequence with the multiplied result and the described phase rotation angle of time domain sample value behind the described conjugate operation.

According to formula 6

$F_u\left(k\right)=A_{C_v}{Z}_u\left(k\right)---\left(6\right)$

Obtain frequency domain ZC sequence.

In the disclosed frequency domain ZC sequence generation of the present embodiment method, adopt a series of equivalent operation, the step that requires to the evaluation type does not appear, avoided because the evaluation type does not match, the amount of calculation that adopts the DFT computing to cause is big, arithmetic speed is slow, problems such as chip area and power consumption increase.

The invention also discloses a kind of generation equipment of frequency domain ZC sequence, be used for substituting existing generation equipment, solve its problem such as computational speed is slow at work, efficient is low.Described under its concrete structure:

Embodiment two

The generation device structure of the disclosed frequency domain ZC sequence of present embodiment comprises as shown in Figure 4:

Time domain ZC sequence generating unit 41, sum unit 42, sampling point selected cell 43, conjugate unit 44, first unit 45, angle generation unit 46 and second unit 47 that multiplies each other that multiplies each other, wherein:

Time domain ZC sequence generating unit 41 is used for generating time domain ZC sequence according to formula; Sum unit 42 be used to calculate described time domain ZC sequence and; Sampling point selected cell 43 is used for selecting the time domain sample value according to default frequency domain index value from described ZC sequence; Conjugate unit 44 is used for the time domain sample value of described selection is carried out conjugate operation; First multiply each other unit 45 be used to obtain described time domain ZC sequence and with described conjugate operation after the multiplied result of time domain sample value; Angle generation unit 46 is used for according to the cyclic shift amount C that sets in advance _vGenerate phase rotation angle; Second unit 47 that multiplies each other is used for described first the multiply each other result of unit and the result of described angle generation unit multiplied each other, and obtains frequency domain ZC sequence.

Wherein first unit 47 that multiplies each other, unit 45 and second that multiplies each other is respectively multiplier.

Each embodiment adopts the mode of going forward one by one to describe in this specification, and what each embodiment stressed all is and the difference of other embodiment that identical similar part is mutually referring to getting final product between each embodiment.For the disclosed device of embodiment, because it is corresponding with the embodiment disclosed method, so description is fairly simple, relevant part partly illustrates referring to method and gets final product.

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

The method of describing in conjunction with embodiment disclosed herein or the step of algorithm can directly use the software module of hardware, processor execution, and perhaps the combination of the two is implemented.Software module can place the storage medium of any other form known in random asccess memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable ROM, register, hard disk, moveable magnetic disc, CD-ROM or the technical field.

To the above-mentioned explanation of the disclosed embodiments, make this area professional and technical personnel can realize or use the present invention.Multiple modification to these embodiment will be conspicuous concerning those skilled in the art, and defined herein General Principle can realize under the situation that does not break away from the spirit or scope of the present invention in other embodiments.Therefore, the present invention will can not be restricted to these embodiment shown in this article, but will meet and principle disclosed herein and features of novelty the wideest corresponding to scope.

Claims (2)

1. the generation method of a frequency domain ZC sequence is characterized in that, comprising:

Generate time domain ZC sequence according to formula;

Calculate described time domain ZC sequence and;

From described ZC sequence, select the time domain sample value according to default frequency domain index value;

The time domain sample value of described selection is carried out conjugate operation;

Obtain described time domain ZC sequence and with described conjugate operation after the multiplied result of time domain sample value;

Generate phase rotation angle according to the cyclic shift amount that sets in advance;

Multiply each other with described time domain ZC sequence with the multiplied result and the described phase rotation angle of time domain sample value behind the described conjugate operation, obtain frequency domain ZC sequence.

2. the generation equipment of a frequency domain ZC sequence is characterized in that, comprising:

Time domain ZC sequence generating unit is used for generating time domain ZC sequence according to formula;

Sum unit, be used to calculate described time domain ZC sequence and;

The sampling point selected cell is used for selecting the time domain sample value according to default frequency domain index value from described ZC sequence;

Conjugate unit is used for the time domain sample value of described selection is carried out conjugate operation;

First unit that multiplies each other, be used to obtain described time domain ZC sequence and with described conjugate operation after the multiplied result of time domain sample value;

The angle generation unit is used for generating phase rotation angle according to the cyclic shift amount that sets in advance;

Second unit that multiplies each other is used for described first the multiply each other result of unit and the result of described angle generation unit multiplied each other, and obtains frequency domain ZC sequence.

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