Summary of the invention
The invention provides a kind of accidental access method, comprise being used for the method that inserts the method for transmitting terminal at random and be used for inserting at random receiving terminal,, reduce the computation complexity of ZC sequence to simplify the flow process that inserts at random based on the ZC sequence.
The invention provides a kind of method that generates frequency domain ZC sequence, to reduce the computation complexity that generates frequency domain ZC sequence.
The invention provides a kind of accidental access method, be used for inserting transmitting terminal at random, comprising based on the ZC sequence:
A, according to formula:
Directly generate frequency domain ZC sequence, wherein: N
ZcBe the crude sampling rate, c is any non-zero constant;
B, generate the time domain ZC sequence that meets the target sample rate according to said frequency domain ZC sequence;
C, the said time domain ZC sequence of transmission.
In the said method, said B can comprise:
Adopt inverse discrete Fourier transformer inverse-discrete said frequency domain ZC sequence directly to be carried out over-sampling, obtain to meet the time domain ZC sequence of target sample rate according to formula (1):
In the formula (1), N
SEQBe the sampling number of targeting sequencing under the target sample rate,
Resource location for frequency domain ZC sequence.
In the said method, said B can comprise:
B1, employing inverse discrete Fourier transformer inverse-discrete are carried out intermediate treatment according to formula (2) to said frequency domain ZC sequence, obtain the intermediate treatment result:
In the formula (2), N
TempFor carrying out the sampling number of intermediate treatment, N
TempSampling number less than targeting sequencing under the target sample rate;
Resource location for frequency domain ZC sequence;
B2, use the over-sampling filter to carry out the time domain interpolate value in time domain, obtain to meet the time domain ZC sequence of target sample rate said intermediate treatment result.
Preferably, the value of said c is 1.
The present invention also provides a kind of accidental access method based on the ZC sequence, is used for inserting receiving terminal at random, comprising:
A, reception signal obtain N according to received signal
ZCThe point frequency domain ZC sequence; Wherein, N
ZcBe the crude sampling rate;
B, according to formula:
generates local frequency domain ZC sequence; Wherein, c ' is any non-zero constant;
C, to said N
ZCPoint frequency domain ZC sequence and local frequency domain ZC sequence are carried out related operation;
D, carry out the detection and the estimation of RACH according to the result of related operation.
Preferably, the value of said c ' is 1.
The present invention also provides a kind of accidental access method based on the ZC sequence, and this method comprises:
Comprise following processing inserting transmitting terminal at random:
According to formula:
Directly generate frequency domain ZC sequence, wherein: N
ZcBe the crude sampling rate, c is any non-zero constant;
Generate the time domain ZC sequence that meets the target sample rate according to said frequency domain ZC sequence;
Send said time domain ZC sequence.
Comprise following processing inserting receiving terminal at random:
Receive signal, obtain N according to received signal
ZCThe point frequency domain ZC sequence; Wherein, N
ZcBe the crude sampling rate;
According to formula:
generates local frequency domain ZC sequence; Wherein, c ' is any non-zero constant;
To said N
ZCPoint frequency domain ZC sequence and local frequency domain ZC sequence are carried out related operation;
Carry out the detection and the estimation of RACH according to the result of related operation.
The present invention also provides a kind of method that generates frequency domain ZC sequence, and this method comprises:
Do not generate original time domain ZC sequence or cyclic shift time domain ZC sequence, but according to formula:
Directly generate frequency domain ZC sequence, wherein: N
ZcBe sampling number, c is any non-zero constant.
Preferably, the value of said c is 1.
Visible by technique scheme, the random access scheme based on the ZC sequence that the present invention proposes makes full use of common factor X in the ZC sequence
u(0) is the character of a constant; When the time domain ZC sequence of aims of systems sample rate is satisfied in the transmitting terminal generation; Do not generate original time domain ZC sequence or cyclic shift time domain ZC sequence; But directly generate the simplification variant of the corresponding frequency domain ZC sequence of this original time domain ZC sequence or cyclic shift time domain ZC sequence; Satisfy the time domain ZC sequence of aims of systems sample rate according to the simplification variant generation of this frequency domain ZC sequence then, thereby simplified handling process and the computation complexity that inserts transmitting terminal at random.And insert at random when detecting with timing estimation at receiving terminal, do the scheme of correlation computations for the employing frequency domain method, also make full use of common factor X when generating local frequency domain ZC sequence
u(0) is the character of a constant, it is moved on to after the IDFT conversion, perhaps replace, thereby simplified handling process and the computation complexity that inserts receiving terminal at random with any non-zero constant.And the receiving terminal scheme that the transmitting terminal scheme that in real system, can only adopt the present invention to propose perhaps only adopts the present invention to propose is promptly used the present invention and is had very big flexible configuration property.
The random access scheme that adopts the present invention to propose, the characteristic that can either make full use of and keep the ZC sequence originally to be had has the generation characteristic of simple again.The present invention is for existing random access scheme, and complexity is lower.When with random access scheme of the present invention with the ZC time domain sequences, when frequency domain sequence generation method fast combines, can reduce amount of calculation significantly.And, the numerical value of above-mentioned any non-zero constant reasonably is provided with, the position of perhaps any non-zero constant being participated in calculating reasonably is provided with, and can significantly reduce computation complexity.
In addition; The invention allows for a kind of method that generates frequency domain ZC sequence; This method does not generate original time domain ZC sequence or cyclic shift time domain ZC sequence, but directly generates the simplification variant of the frequency domain ZC sequence of this original time domain ZC sequence or cyclic shift time domain ZC sequence correspondence.The scope of application of this method is very extensive; In the technical scheme of any employing ZC of communication system sequence; The ZC sequence generation scheme that is adopted in the original system can be reduced to the ZC sequence generation scheme of the variant of the present invention's proposition; And need not do any change to other designs such as the radio frequency of system, intermediate frequency, base band and algorithm, the change of the optimization method that promptly ZC sequence time domain waveform is generated according to the present invention has independence.
Adopt the random access leader sequence that technical scheme of the present invention generated; Compare with the ZC sequence that the ZC sequence generating method of the theory that does not adopt the present invention to be optimized is generated; The character of the ZC sequence that the present invention generated can't change; For example: characteristics such as the antithesis characteristic of the desirable autocorrelation performance of the sequence of in the LTE system, using and their cross correlation, sequence, leading CM (Cubic Metric) characteristic and root parameter marshalling can not change; Therefore; The random access leader sequence that adopts technical scheme of the present invention to generate can be transplanted in any use ZC sequence other communication system as random access leader sequence at an easy rate, and need not design again system.
Embodiment
For making the object of the invention, technical scheme and advantage clearer, below with reference to the accompanying drawing embodiment that develops simultaneously, the present invention is done further explain.
Fig. 1 is the handling process principle schematic of existing random access scheme.Brief description is made in the processing of carrying out in the face of each module among Fig. 1 down:
Transmitting terminal comprises module 1~module 5, wherein:
Module 1 is used to generate N
ZcPoint time domain ZC sequence, this sequence is called original time domain ZC sequence;
Module 2 is used for original time domain ZC sequence is carried out cyclic shift;
Module 3 is used for the time domain ZC sequence that after cyclic shift, obtains is carried out the DFT conversion, transforms to frequency domain;
Module 4 is used for the frequency domain ZC sequence that after the DFT conversion, obtains is mapped to N
SeqThe point frequency domain ZC sequence, wherein, N
SeqBe the aims of systems sample rate;
Module 5 is used for N
SeqThe point frequency domain ZC sequence is carried out the IDFT conversion, transforms to time domain, is met the time domain ZC sequence of aims of systems sample rate.
The time domain ZC sequence that satisfies the aims of systems sample rate is transferred to receiving terminal by the transmitting terminal channel.
Receiving terminal comprises module 6~module 10, wherein:
Module 6 is used for the N to receiving
SeqPoint time domain ZC sequence is carried out the DFT conversion, transforms to frequency domain;
Module 7 is used for the N that obtains after the DFT conversion
SeqThe point frequency domain ZC sequence is separated mapping and is obtained N
ZcThe point frequency domain ZC sequence;
Module 9 is used to generate local N
ZcThe point frequency domain ZC sequence, and send to module 8;
Module 8 is used for the N from module 7
ZcThe point frequency domain ZC sequence with from the local N of module 9
ZcThe point frequency domain ZC sequence is carried out dot product;
Module 10 is used for carrying out according to the result of dot product the detection and the estimation of RACH.
Defining original time domain ZC sequence is:
In the formula (1), N
ZcBe the crude sampling rate, the frequency domain form of original time domain ZC sequence is shown in the formula (1):
Original time domain ZC sequence shown in the formula (1) is carried out cyclic shift, and the cyclic shift time domain ZC sequence that obtains is:
x
u,v(n)=x
u((n+C
v)mod?N
ZC) (3)
Then the frequency domain form of this cyclic shift time domain ZC sequence is:
The present inventor finds: in random access scheme, and when u is determined value, the X in formula (2) and the formula (4)
u(0) be a constant, therefore, present patent application proposes: this constant can move to any part in the linear process flow process that inserts handling process at random.Further in theory, X
u(0) can move in the equivalent channel model of system; It is negligible often in the design of wireless communication system; Therefore, this discovery not only can be applied in the random access scheme, can also be applied in the technical scheme of any employing ZC of communication system sequence.
Because the frequency domain form of original time domain ZC sequence shown in the formula (1) is C in the formula (4)
vTherefore=0 situation, no longer describes formula respectively to the frequency domain form of the frequency domain form of original time domain ZC sequence or cyclic shift time domain ZC sequence below.
According to top analysis to time domain, frequency domain ZC sequence generation formula, the present inventor draws: comprise a constant in the frequency domain ZC sequence, this constant can move to any part in the linear process flow process that inserts handling process at random.The present invention makes full use of the above-mentioned character of ZC sequence, and the transmitting terminal that adopts the scheme that the ZC sequence inserts at random and the handling process of receiving terminal are optimized, and has proposed a kind of low random access scheme based on the ZC sequence of computation complexity of flexible configuration.
The main thought that the present invention is based on the random access scheme of ZC sequence is:
When the time domain ZC sequence of aims of systems sample rate is satisfied in the transmitting terminal generation; Do not generate original time domain ZC sequence or cyclic shift time domain ZC sequence (among the application; Both are referred to as time domain ZC sequence); But directly generating the simplification variant of the corresponding frequency domain ZC sequence of this time domain ZC sequence, the simplification variant according to this frequency domain ZC sequence generates the time domain ZC sequence that satisfies the aims of systems sample rate then.Wherein, when generating the simplification variant of frequency domain ZC sequence, can be with the common factor X in formula (2) or the formula (4)
u(0) gives up, promptly replace with constant 1.Certainly, also can use other non-zero constant replacement arbitrarily.
When receiving terminal inserts detection and timing estimation at random; For adopting frequency domain method to do the scheme of correlation computations, when generating local frequency domain ZC sequence, can the common factor in the formula be moved on to after the IDFT conversion; And this common factor also can be given up, and promptly replaces with constant 1.Certainly, also can use other non-zero constant replacement arbitrarily.
Above-mentioned main thought inserts at random according to the present invention, and the characteristic that can either make full use of and keep the ZC sequence originally to be had has the generation characteristic of simple again.The present invention is for existing random access scheme, and complexity is lower.When with random access scheme of the present invention with the ZC time domain sequences, when frequency domain sequence generation method fast combines, can reduce amount of calculation significantly.And, the numerical value of above-mentioned any non-zero constant reasonably is provided with, the position of perhaps any non-zero constant being participated in calculating reasonably is provided with, and can significantly reduce computation complexity.
In addition; The scope of application of technical scheme of the present invention is very extensive; In the technical scheme of any employing ZC of communication system sequence; Can generate scheme to the ZC sequence that the ZC sequence generation scheme that is adopted in the original system be reduced to the variant that the present invention proposes, and need not do any change to other designs such as the radio frequency of system, intermediate frequency, base band and algorithm, the change of the optimization method that promptly ZC sequence time domain waveform is generated according to the present invention has independence.And the receiving terminal scheme that the transmitting terminal scheme that in real system, can only adopt the present invention to propose perhaps only adopts the present invention to propose is promptly used the present invention and is had very big flexible configuration property.
The random access scheme that proposes in the face of the present invention down is elaborated.
The transmitting terminal of the random access scheme that the present invention proposes comprises: transmitting terminal first module and transmitting terminal second module, and as shown in Figure 2.The flow process that transmitting terminal sends random access leader sequence is: at first generate the frequency domain ZC sequence corresponding to original time domain ZC sequence or cyclic shift time domain ZC sequence by transmitting terminal first module, that is: generate the simplification variant of frequency domain ZC sequence; Generate corresponding over-sampling time domain sequences by transmitting terminal second module according to this frequency domain ZC sequence then.Particularly:
The processing of transmitting terminal first module can be formulated as:
Promptly give up X in the formula (4)
u(0) this constant.
The handling process of transmitting terminal second module has several kinds, lists preferable two kinds below:
First kind of handling process: this module adopts frequency domain ZC sequence shown in the IDFT transfer pair formula (5) directly to carry out over-sampling, obtains to meet the time domain ZC sequence of target sample rate.The sampling number of order targeting sequencing under the target sample rate is N
SEQ, the generation formula of the time domain ZC sequence of over-sampling is so:
is the resource location of frequency domain ZC sequence in the formula (6).Different to the definition of DFT/IDFT with processing apparatus according to different disposal software, the coefficient in the formula (6)
maybe be different.
Second kind of handling process: the mode that this module adopts IDFT conversion and time domain oversampling to combine generates over-sampling time domain ZC sequence.
At first, use the over-sampling of frequency domain sequence shown in the formula (5) being done a less multiplying power or non-integer multiplying power than the IDFT of small point.This step is an intermediate process steps, will obtain one suc as formula the intermediate treatment result shown in (7).Here, be appreciated that to less than target sample rate corresponding sampling points number than small point.
In the formula (7), N
TempFor carrying out the sampling number of the said intermediate treatment of this step.Different to the definition of DFT/IDFT with processing apparatus according to different disposal software, the coefficient in the formula (7)
maybe be different.
Then, use the over-sampling filter to carry out the time domain interpolate value in time domain, to obtain to meet the time domain ZC sequence of target sample rate to time domain ZC sequence shown in the formula (7).
The receiving terminal of the random access scheme that the present invention proposes comprises: receiving terminal first module, receiving terminal second module, receiving terminal three module and receiving terminal four module, and as shown in Figure 3.The flow process that receiving terminal receives random access leader sequence is:
At first, obtain N by receiving terminal first module according to received signal
ZCThe point frequency domain ZC sequence.The processing of this module can be carried out according to prior art, for example: referring to Fig. 1, will obtain N in module 7
ZCThe point frequency domain ZC sequence repeats no more at this to the detailed process of this module.
Then, generate local frequency domain ZC sequence by receiving terminal second module.The formula that receiving terminal second module generates local frequency domain ZC sequence is:
Corresponding to the processing of transmitting terminal first module, likewise also given up X
u(0) this.
Again by the receiving terminal three module to N from receiving terminal first module
ZCPut frequency domain ZC sequence and carry out related operation from the local frequency domain ZC sequence of receiving terminal second module.The processing of receiving terminal three module is carried out dot product with both exactly, can be formulated as:
In the formula (8), N
DetecBeing counting of IDFT conversion, is the sampling number corresponding to correlated series under the set sample rate.
At last, carry out the detection and the estimation of RACH by the receiving terminal four module according to the result of related operation, whether this module is used for detecting has the user to arrive, if having the user to arrive then estimate timing position.
The above-mentioned random access scheme based on the ZC sequence that the present invention proposes is equivalent to the module 1 in the existing random access scheme shown in Figure 1, module 2, module 3, module 8, module 9 are improved in the function and the calculating that insert at random in the handling process; Simplify the flow process of existing random access scheme, reduced computation complexity.
More than random access scheme that the present invention is proposed based on the ZC sequence specify.On the basis of technique scheme, can also expand.A kind of technical scheme of expansion is:
Transmitting terminal first module adopts following formula to generate frequency domain sequence:
In the formula (9), c is any non-zero constant.
Correspondingly, in receiving terminal second module, the generation formula of local frequency domain sequence is:
In the formula (10), c ' is any non-zero constant.
Adopt the random access leader sequence that technical scheme of the present invention generated; Compare with the ZC sequence that the ZC sequence generating method of the theory that does not adopt the present invention to be optimized is generated; The character of the ZC sequence that the present invention generated can't change; For example: characteristics such as the antithesis characteristic of the desirable autocorrelation performance of the sequence of in the LTE system, using and their cross correlation, sequence, leading CM (Cubic Metric) characteristic and root parameter marshalling can not change; Therefore; The random access leader sequence that adopts technical scheme of the present invention to generate can be transplanted in any use ZC sequence other communication system as random access leader sequence at an easy rate, and need not design again system.
The above is merely preferred embodiment of the present invention, and is in order to restriction the present invention, not all within spirit of the present invention and principle, any modification of being made, is equal to replacement, improvement etc., all should be included within the scope that the present invention protects.